Change search
Refine search result
1234 51 - 100 of 159
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 51.
    Junesand, Carl
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Olsson, Fredrik
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Xiang, Yu
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Gau, Ming-Horng
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Surface morphology of indium phosphide grown on silicon by nano-epitaxial lateral overgrowth2009In: Physica Status Solidi. C, Current topics in solid state physics, ISSN 1610-1634, E-ISSN 1610-1642, Vol. 6, no 12, p. 2785-2788Article in journal (Refereed)
    Abstract [en]

    InP is grown on Si by nano-epitaxial lateral overgrowth (NELOG or nano-ELOG) on patterns consisting of net-type openings under different growth conditions. Surface morphology is characterized with AFM and profilometer and optical quality assessed by Micro Photoluminescence measurements (mu-PL). Results show that growth conditions affect both morphology and optical quality, with thicker layers generally corresponding to better surface morphology. Lower growth temperature seems to improve surface morphology irrespective of thickness, and ELOG layers exhibit significantly better morphology than the planar layer.

  • 52.
    Junesand, Carl
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Wang, Zhechao
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    InP overgrowth on SiO2 for active photonic devices on silicon2010In: Proceedings of SPIE - The International Society for Optical Engineering, SPIE - International Society for Optical Engineering, 2010, Vol. 7606Conference paper (Refereed)
    Abstract [en]

    ntegrationof III-V materials on silicon wafer for active photonic deviceshave previously been achieved by growing thick III-V layers ontop of silicon or by bonding the III-V stack layersonto a silicon wafer. Another way is the epitaxial lateralovergrowth (ELOG) of a thin III-V material from a seedlayer directly on the silicon wafer, which can be usedas a platform for the growth of active devices. Asa prestudy, we have investigated lateral overgrowth of InP byHydride Vapor Phase Epitaxy (HVPE) over SiO2 masks of differentthickness on InP substrates from openings in the mask. Openingswhich varied in direction, width and separation were made withE-beam lithography allowing a good dimension control even for nano-sizedopenings (down to 100 nm wide). This mimics overgrowth ofInP on top of SiO2/Si waveguides. By optimizing the growthconditions in terms of growth temperature and partial pressure ofthe source gases with respect to the opening direction, separationand width, we show that a thin (~200 nm) layerof InP with good morphology and crystalline quality can begrown laterally on top of SiO2. Due to the thingrown InP layer, amplification structures on top of it canbe well integrated with the underlying silicon waveguides. The proposedELOG technology provides a promising integration platform for hybrid InP/siliconactive devices.

  • 53. Kamp, M.
    et al.
    Hofmann, J.
    Forchel, A.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Ultrashort InGaAsP/InP lasers with deeply etched Bragg mirrors2001In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 78, no 26, p. 4074-4075Article in journal (Refereed)
    Abstract [en]

    We have fabricated short cavity lasers with deeply etched Bragg mirrors based on 1.55 mum emitting InGaAsP/InP laser structures. Continuous-wave operation has been obtained for devices with a length of 40 mum, showing threshold currents of 12 mA. The dynamic properties of the lasers were studied by measurements of the relative intensity noise (RIN). A maximum modulation frequency of 8.4 GHz was extracted from the RIN data.

  • 54.
    Kataria, Himanshu
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Wang, Zhechao
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Metaferia, Wondwosen
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Sun, Yan-Ting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Bazin, Alexandre
    CNRS.
    Raineri, Fabrice
    CNRS.
    Mages, Phil
    UCSB.
    Julian, Nick
    UCSB.
    Bowers, John
    UCSB.
    Towards a monolithically integrated III-V laser on silicon: Optimization of multi-quantum well growth of InP on Si2013In: Semiconductor Science and Technology, ISSN 0268-1242, E-ISSN 1361-6641, Vol. 28, no 9, p. 094008-Article in journal (Refereed)
    Abstract [en]

    High-quality InGaAsP/InP multi-quantum wells (MQWs) on the isolated areas of indium phosphide on silicon necessary for realizing a monolithically integrated silicon laser is achieved. Indium phosphide layer on silicon, the pre-requisite for the growth of quantum wells is achieved via nano-epitaxial lateral overgrowth (NELOG) technique from a defective seed indium phosphide layer on silicon. This technique makes use of epitaxial lateral overgrowth (ELOG) from closely spaced (1 m) e-beam lithography-patterned nano-sized openings (∼300 nm) by low-pressure hydride vapor phase epitaxy. A silicon dioxide mask with carefully designed opening patterns and thickness with respect to the opening width is used to block the defects propagating from the indium phosphide seed layer by the so-called necking effect. Growth conditions are optimized to obtain smooth surface morphology even after coalescence of laterally grown indium phosphide from adjacent openings. Surface morphology and optical properties of the NELOG indium phosphide layer are studied using atomic force microscopy, cathodoluminescence and room temperature -photoluminescence (-PL) measurements. Metal organic vapor phase epitaxial growth of InGaAsP/InP MQWs on the NELOG indium phosphide is conducted. The mask patterns to avoid loading effect that can cause excessive well/barrier thickness and composition change with respect to the targeted values is optimized. Cross-sectional transmission electron microscope studies show that the coalesced NELOG InP on Si is defect-free. PL measurement results indicate the good material quality of the grown MQWs. Microdisk (MD) cavities are fabricated from the MQWs on ELOG layer. PL spectra reveal the existence of resonant modes arising out of these MD cavities. A mode solver using finite difference method indicates the pertinent steps that should be adopted to realize lasing.

  • 55.
    Kataria, Himanshu
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Metaferia, Wondwosen
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Junesand, Carl
    Sun, Yanting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Loududoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Monolithic integration of InP based structures on silicon for optical interconnects2014In: 2014 ECS and SMEQ Joint International Meeting, 2014, no 6, p. 523-531Conference paper (Refereed)
    Abstract [en]

    Monolithic integration of InP based structures on Si for optical interconnects is presented. Different strategies are demonstrated to achieve requisite InP platform on Si. In the first strategy, defect free isolated areas of epitaxially and laterally overgrown InP are obtained on Si and the InGaAsP based quantum wells directly grown on these templates have shown high material quality with uniform interfaces. In the second strategy, selective area growth is exploited to achieve InP nano pyramids on Si which can be used for the growth of quantum dot structures. In the third and the final strategy, a method is presented to achieve direct interface between InP and Si using corrugated epitaxial lateral overgrowth.

  • 56.
    Kataria, Himanshu
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Metaferia, Wondwosen
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Zhang, Chong
    Julian, Nick
    Bowers, John E.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Simple Epitaxial Lateral Overgrowth Process as a Strategy for Photonic Integration on Silicon2014In: IEEE Journal of Selected Topics in Quantum Electronics, ISSN 1077-260X, E-ISSN 1558-4542, Vol. 20, no 4, p. 8201407-Article in journal (Refereed)
    Abstract [en]

    In this paper we propose a strategy to achieve monolithic integration of III-Vs on Si for photonic integration through a simple process. By mimicking the SiO2/Si/SiO2 waveguide necessary to couple light from the gain medium on its top, we adopt a similar to 2 mu m thick silicon dioxide mask for epitaxial lateral overgrowth (ELOG) of InP on Si. The ELOG InP layer as wells as the subsequently grown quantum wells (similar to 1. 55 mu m) have been analyzed by photoluminescence and transmission electron microscopy and found to have high optical quality and very good interface. The studies are strategically important for a monolithic platform that holds great potential in addressing the future need to have an integrated platform consisting of both III-Vs and Si on same chip.

  • 57.
    Kataria, Himanshu
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Metaferia, Wondwosen
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Nagarajan, Murali
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Sun, Yanting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Carrier-transport, optical and structural properties of large area ELOG InP on Si using conventional optical lithography2013In: 2013 International Conference on Indium Phosphide and Related Materials (IPRM), IEEE conference proceedings, 2013, p. 6562592-Conference paper (Refereed)
    Abstract [en]

    We present the carrier-transport, optical and structural properties of InP deposited on Si by Epitaxial Lateral Overgrowth (ELOG) in a Low Pressure-Hydride Vapor phase epitaxy (LP-HVPE). Hall measurements, micro photoluminescence (μ-PL) and X-ray diffraction (XRD) were used to study the above-mentioned respective properties at room temperature. It is the first time that electrical properties of ELOG InP on Si are studied by Hall measurements. Prior to ELOG, etching of patterned silicon dioxide (SiO2) mask leading to a high aspect ratio, i. e. mask thickness to opening width >2 was optimized to eliminate defect propagation even above the opening. Dense high aspect ratio structures were fabricated in SiO2 to obtain ELOG InP on Si, coalesced over large area, making it feasible to perform Hall measurements. We examine this method and study Hall mobility, strain and optical quality of large area ELOG InP on Si.

  • 58.
    Kataria, Himanshu
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Metaferia, Wondwosen T.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Zhang, Chong
    Bowers, John E.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    High quality large area ELOG InP on silicon for photonic integration using conventional optical lithography2014In: SMART PHOTONIC AND OPTOELECTRONIC INTEGRATED CIRCUITS XVI, 2014, p. 898904-Conference paper (Refereed)
    Abstract [en]

    A simple method of growing large areas of InP on Si through Epitaxial Lateral Overgrowth (ELOG) is presented. Isolated areas of high quality InP suitable for photonic integration are grown in deeply etched SiO2 mask fabricated using conventional optical lithography and reactive ion etching. This method is particularly attractive for monolithically integrating laser sources grown on InP with Si/SiO2 waveguide structure as the mask. The high optical quality of multi quantum well (MQW) layers grown on the ELOG layer is promisingly supportive of the feasibility of this method for mass production.

  • 59.
    Kjebon, Olle
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Hammarlund, B.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Lindgren, S.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Rask, M
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Ojala, P.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Landgren, Gunnar
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Broberg, B.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    1.55 μm buried heterostructure laser via regrowth of semi-insulating InP:Fe around vertical mesas fabricated by reactive ion etching using methane and hydrogen1991In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 59, no 3, p. 235-255Article in journal (Refereed)
    Abstract [en]

    A GaInAsP/InP Fabry-Perot-type buried-heterostructure quantum well laser operating at 1.55 μm has been realized utilizing iron-doped semi-insulating InP around vertical mesas fabricated by reactive ion etching using methane and hydrogen. A maximum cw output power of 19 mW has been achieved on as-cleaved chips of 300 μm length with a quantum efficiency of 21% per facet. Threshold currents lie between 20 and 25 mA. As low as 2 Ω series resistance has been measured despite an ohmic contact area not exceeding that of the 2-μm-wide mesa. A 3 dB bandwidth of 7.5 GHz at 12 mW output power is obtained from the small-signal frequency modulation measurements.

  • 60.
    Kjebon, Olle
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Wallin, J
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Regrowth of semi-insulating iron doped InP around reactive ion etched laser mesas in <110> and <-110> directions by hydride vapour phase epitaxy1992In: Indium Phosphide and Related Materials, 1992., Fourth International Conference on, 1992, p. 48-50Conference paper (Other academic)
    Abstract [en]

    Hydride vapor phase epitaxy (HVPE) has been used for regrowth of semi-insulating iron doped InP around reactive ion etched laser mesas in <110> and <-110> directions. The regrowth morphology and the electrical properties are similar in both cases. It is also demonstrated that HVPE is a quick and easy technique to realize buried heterostructure (BH) lasers in both <110> and <-110> directions

  • 61.
    Kjebon, Olle
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Wallin, J
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Westergren, Urban
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Lindgren, S
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Extremely Low Parasitic 1.55 mm Lasers for Direct Amplitude High Frequency Modulation up to 20 GHz1992In: ECOC'93 , vol. 2: 19th European Conference on Optical Communication, Montreux, Switzerland, 1992, p. 201-204Conference paper (Other academic)
  • 62.
    Kjebon, Olle
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Schatz, Richard
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP. KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Nilsson, Stefan
    KTH, Superseded Departments, Electronics.
    Stålnacke, Björn
    KTH, Superseded Departments, Electronics.
    Modulation response measurements and evaluation of MQW InGaAsP lasers of various designs1996In: Proc. SPIE, Vol. 2684, 1996, p. 138-152Conference paper (Other academic)
    Abstract [en]

    Resultsfrom modulation measurements of 40 high-speed multi quantum well (MQW)lasers ((lambda) equals 1.55 micrometer) of various designs are presented.By fitting the careful calibrated measurements, both magnitude and phase,to an analytical transfer function we were able to determineif a certain laser was limited by thermal effects, parasitic-likeeffects, or nonlinear gain effects. We found that most ofthe devices in the study were limited by thermal effectsand/or contact parasitics. The parasitics were found to be determinedby the width of the high-doped contact layer and claddinglayers below the metallic contact. It was also found thata high doping of the separate confinement heterostructure (SCH) layersdecreases the damping of the relaxation peak since it facilitatesthe carrier transport. Improved contact design and high doped SCH-layersresulted in modulation bandwidths of around 24 GHz.

  • 63.
    Kjebon, Olle
    et al.
    KTH, Superseded Departments, Electronics.
    Schatz, Richard
    KTH, Superseded Departments, Electronics.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Electronics.
    Nilsson, Stefan
    KTH, Superseded Departments, Electronics.
    Stålnacke, Björn
    KTH, Superseded Departments, Electronics.
    Bäckbom, Lena
    KTH, Superseded Departments, Electronics.
    30GHz direct modulation bandwidth indetuned loaded InGaAsP DBR lasers at1.55 μm wavelength1997In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 33, p. 488-489Article in journal (Refereed)
    Abstract [en]

    An increased resonance frequency and reduced damping of theresonance peak leading to a record high modulation bandwidth of30GHz were observed in 1.55 mm InGaAsP DBR lasers. Theseresults are attributed to the mechanism of detuned loading.

  • 64.
    Kjebon, Olle
    et al.
    KTH, Superseded Departments, Electronics.
    Öhlander, U
    KTH, Superseded Departments, Electronics.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Electronics.
    Wallin, J
    KTH, Superseded Departments, Electronics.
    Streubel, K
    KTH, Superseded Departments, Electronics.
    Nilsson, S
    KTH, Superseded Departments, Electronics.
    Klinga, T
    KTH, Superseded Departments, Electronics.
    Multi quantum well 1.55 μm DFB lasers with low threshold current, high resonance frequency and bandwidth at low current injection1994In:  Semiconductor Laser Conference, 1994: 14th IEEE International, 1994, p. 221-222Conference paper (Other academic)
    Abstract [en]

    Summary form only given. Multi quantum well GaInAsP DFB buried heterostructure lasers with low threshold, 3.4 mA, large slope of resonance frequency versus square root of current above threshold, 2.6 GHz/mA1/2 and high maximum bandwidth, 21.7 GHz, have been fabricated

  • 65.
    Lankinen, A.
    et al.
    Optoelectronics Laboratory, Helsinki University of Technology.
    Tuomi, T.
    Optoelectronics Laboratory, Helsinki University of Technology.
    Karilahti, M.
    Optoelectronics Laboratory, Helsinki University of Technology.
    Zytkiewicz, Z. R.
    Institute of Physics, Polish Academy of Sciences.
    Domagala, J. Z.
    Institute of Physics, Polish Academy of Sciences.
    McNally, P. J.
    Research Institute for Networks and Communications Engineering, Dublin City University.
    Sun, Yan-Ting
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Olsson, Fredrik
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Crystal Defects and Strain of Epitaxial InP Layers Laterally Overgrown on Si2006In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 6, no 5, p. 1096-1100Article in journal (Refereed)
    Abstract [en]

    Defects in epitaxial laterally overgrown (ELO) InP layers are examined by high-resolution X-ray diffraction and synchrotron X-ray back-reflection and transmission topography. X-ray diffraction maps produce information about the overall crystal quality of the epitaxial layers in the InP ELO sample. The topographs show small angle boundaries, and the associated dislocations are located at the boundaries between the crystallites; allowing for their relative tilt, the maximum value for this is 0.06 degrees. No defects inside the crystallites can be seen in the topographs, except for a small bending of 0.04 degrees at most, of the ELO lattice planes. The section topographs show deformed X-ray interference fringes resulting from the large strain of the silicon lattice below the seeding areas.

  • 66. Liang, Y.
    et al.
    Peretti, R.
    Liverini, V.
    Süess, M. J.
    Vigneron, P. -B
    Wolf, J. M.
    Bonzon, C.
    Bismuto, A.
    Lourdudoss, Sebastian
    KTH, School of Engineering Sciences (SCI), Applied Physics, Semiconductor Materials, HMA.
    Metaferia, W.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Semiconductor Materials, HMA.
    Balaji, M.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Semiconductor Materials, HMA.
    Gini, E.
    Beck, M.
    Faist, J.
    Buried heterostructure photonic crystal quantum cascade laser: Towards 2D large-area single-mode operation2016In: Optics InfoBase Conference Papers, OSA - The Optical Society , 2016Conference paper (Refereed)
    Abstract [en]

    We demonstrate a buried-heterostructure photonic-crystal quantum cascade laser operating at room temperature. The large-area coherent lasing enabled an output peak power of 0.88 W at 263 K with single-mode behavior and narrow far field pattern.

  • 67.
    Liu, X. Y.
    et al.
    Chalmers University of Technology.
    Aggerstam, Thomas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Holmström, P.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Andersson, T.G.
    Cracks in GaN/AlN multiple quantum well structures grown by MBE2008In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 100, p. 042026-Article in journal (Refereed)
    Abstract [en]

    Due to the large lattice constant mismatch and thermal expansion coefficient difference between GaN and AlN, large strain is generated inside the GaN/AlN multiple quantum wells, which causes cracks in the structure. We investigated such cracks by optical microscopy and AFM. The crack density was studied with buffer and cap layer thickness, the number of quantum well periods, and the temperature reduction rate after growth as parameters. It was found that the crack density increased exponentially, with the number of periods above 4. Besides, a very thin, 100 nm, GaN buffer layer and similar to 300 nm GaN cap layer greatly reduced the crack density.

  • 68. Liu, X. Y.
    et al.
    Janes, P.
    Holmstrom, P.
    Aggerstam, T.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Andersson, T. G.
    Growth of GaN and GaN/AlN multiple quantum wells on sapphire, Si and GaN template by molecular beam epitaxy2007In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 300, no 1, p. 79-82Article in journal (Refereed)
    Abstract [en]

    GaN layers of 280 nm thick were grown on sapphire, silicon (1 1 1) and GaN template by plasma assisted molecular beam epitaxy. From atomic force microscopy and high-resolution X-ray diffraction, it was found that GaN grown on sapphire and template gave smooth surface (RMS less then 0.5 nm) and very high crystalline quality (FWHM of (0 0 0 2) scan on sapphire only 48 arcsec). However, GaN growth on Si (1 1 1) provided rough surface and poor crystalline quality. The GaN/AlN multiple quantum well structures were grown on sapphire and template. Intersubband absorption spectra from Fourier transform infrared spectroscopy indicated that layers on GaN templates had better performances than on sapphire substrates.

  • 69. Liu, X.Y
    et al.
    Aggerstam, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Andersson, T. G.
    Investigation of intersubband absorption of GaN/AlN multiple quantum wells grown on different substrates by molecular beam epitaxy2007In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 301, no SPEC. ISS., p. 301-302Article in journal (Refereed)
    Abstract [en]

    Ten period GaN/AlN multiple quantum well (MQW) structures were grown by plasma-assisted molecular beam epitaxy (MBE) on sapphire substrates and metal-organic vapour-phase epitaxy (MOVPE)-grown GaN templates. Samples were investigated by high-resolution X-ray diffraction (HR-XRD) and Fourier transform infrared (FT-IR) spectroscopy. Intersubband (IS) absorbances and FWHM of IS absorption peaks indicated that samples grown on the GaN templates had better characteristics, resulting in a FWHM as low as 93 meV at a peak energy of 700 meV.

  • 70. Lo, Ikai
    et al.
    Gau, M. H.
    Tsai, J. K.
    Chen, Y. L.
    Chang, Z. J.
    Wang, W. T.
    Chiang, J. C.
    Aggerstam, T.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Anomalous k-dependent spin splitting in wurtzite AlxGa1-xN/GaN heterostructures2007In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 75, no 24Article in journal (Refereed)
    Abstract [en]

    We have observed the k-dependent spin splitting in wurtzite AlxGa1-xN/GaN heterostructures. An anomalous beating pattern was observed in Shubnikov-de Haas measurements due to the interference of Rashba and Dresselhaus spin-orbit interactions. The dominant mechanism for the k-dependent spin splitting at high values of k is attributed to Dresselhaus term which is enhanced by the Delta(C1)-Delta(C3) coupling of wurtzite band folding effect. The interference of Rashba and Dresselhaus effects in the AlxGa1-xN/GaN heterostructure provides a potential candidate for the gate-controlled spin-polarized spintronic devices.

  • 71. Lo, Ikai
    et al.
    Tsai, J. K.
    Gau, M. H.
    Chen, Y. L.
    Chang, Z. J.
    Wang, W. T.
    Chiang, J. C.
    Wang, K. R.
    Chen, C-N
    Aggerstam, Thomas
    KTH, School of Information and Communication Technology (ICT), Centres, Electrum Laboratory, ELAB.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Centres, Electrum Laboratory, ELAB.
    Study of two-subband population in Fe-doped AlxGa1-xN/GaN heterostructures by persistent photoconductivity effect2006In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 74, no 24, p. 245325-Article in journal (Refereed)
    Abstract [en]

    The electronic properties of Fe-doped Al0.31Ga0.69N/GaN heterostructures have been studied by Shubnikov-de Haas measurement. The lowest two subbands of the two-dimensional electron gas in the heterointerface were populated. After the low temperature illumination, the electron density increases from 11.99x10(12) cm(-2) to 13.40x10(12) cm(-2) for the first subband and from 0.66x10(12) cm(-2) to 0.94x10(12) cm(-2) for the second subband. The persistent photoconductivity effect (similar to 13% increase) is mostly attributed to the Fe-related deep-donor level in GaN layer. The second subband starts to populate when the first subband is filled at a density of 9.40x10(12) cm(-2). We obtained the energy separation between the first and second subbands to be 105 meV.

  • 72.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Heteroepitaxy and selective area heteroepitaxy for silicon photonics2012In: Current opinion in solid state & materials science, ISSN 1359-0286, E-ISSN 1879-0348, Vol. 16, no 2, p. 91-99Article, review/survey (Refereed)
    Abstract [en]

    This article reviews the major achievements in recent years on heteroepitaxy and selective area heteroepitaxy that are relevant to silicon photonics. Material aspects are given due importance without trying to cover all kinds of devices. Under heteroepitaxy several systems based on GaAs, InP and GaSb and their related materials and dilute III-nitrides all on Si substrates are covered and assessed. Quantum dot and quantum well lasers are taken as device examples. The potential of the emerging SnGeSi/Si system is highlighted. Under selective area heteroepitaxy, growth of InP from SiO2 trenches in Si and epitaxial lateral overgrowth of InP on silicon are exemplified as the potential routes for monolithic integration on silicon. The expected trends and anticipated advances are indicated.

  • 73.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Heteroepitaxy of InP on Si for photonic and photovoltaic applications2016In: 2016 COMPOUND SEMICONDUCTOR WEEK (CSW) INCLUDES 28TH INTERNATIONAL CONFERENCE ON INDIUM PHOSPHIDE & RELATED MATERIALS (IPRM) & 43RD INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS (ISCS), IEEE, 2016Conference paper (Refereed)
  • 74.
    Lourdudoss, Sebastian
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Bowers, John E.
    Univ Calif Santa Barbara, Inst Energy Efficiency, Santa Barbara, CA 93106 USA..
    Jagadish, Chennupati
    Australian Natl Univ, Res Sch Phys & Engn, Dept Elect Mat Engn, Canberra, ACT 2601, Australia..
    SEMICONDUCTORS AND SEMIMETALS Future Directions in Silicon Photonics Preface2019In: FUTURE DIRECTIONS IN SILICON PHOTONICS / [ed] Lourdudoss, S Bowers, JE Jagadish, C, ELSEVIER ACADEMIC PRESS INC , 2019, p. XV-XVIIIChapter in book (Refereed)
  • 75.
    Lourdudoss, Sebastian
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Chen, R. T.
    Jagadish, C.
    Preface2018In: Semiconductors and Semimetals, Academic Press Inc. , 2018, p. ix-xiChapter in book (Refereed)
  • 76.
    Lourdudoss, Sebastian
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Hammarlund, Bo
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Kjebon, Olle
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    An investigation on hydride VPE growth and properties of semi-insulating InP:Fe1990In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 19, no 9, p. 981-987Article in journal (Refereed)
    Abstract [en]

    Growth of highly resistive semi-insulating InP : Fe has been achieved by the Hydride VPE technique in an ambient consisting mostly of nitrogen. After dealing with some thermodynamic considerations pertinent to InP:Fe growth, the experimental growth parameters are described. It is shown that various amounts of iron can be introduced into the InP crystal just by varying the temperature of the iron source. The crystal quality of the grown material is estimated to be good by etch pit density and x-ray diffraction analyses. Current-voltage behaviour and capacitance studies on an n+-SI-n+ structure are explained by invoking the theory of current injection in solids by Lampert and Mark: the experimental current densities at the threshold of each observed regime are compared with the theoretically derived current densities; in the absence of current injection, the measured capacitance is found to be the same as the geometrical capacitance.

  • 77.
    Lourdudoss, Sebastian
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    Kataria, Himanshu
    Metaferia, Wondwosen
    Omanakuttan, Giriprasanth
    KTH, School of Engineering Sciences (SCI), Applied Physics, Semiconductor Materials, HMA.
    Sun, Yan-Ting
    KTH, School of Engineering Sciences (SCI), Applied Physics, Semiconductor Materials, HMA.
    Wang, Zhechao
    Olsson, Fredrik
    Trends in heteroepitaxy of III-Vs on silicon for photonic and photovoltaic applications2017In: SMART PHOTONIC AND OPTOELECTRONIC INTEGRATED CIRCUITS XIX / [ed] Eldada, LA Lee, EH He, S, 2017, article id UNSP 1010705Conference paper (Refereed)
    Abstract [en]

    We present and compare the existing methods of heteroepitaxy of III-Vs on silicon and their trends. We focus on the epitaxial lateral overgrowth (ELOG) method as a means of achieving good quality III-Vs on silicon. Initially conducted primarily by near-equilibrium epitaxial methods such as liquid phase epitaxy and hydride vapour phase epitaxy, nowadays ELOG is being carried out even by non-equilibrium methods such as metal organic vapour phase epitaxy. In the ELOG method, the intermediate defective seed and the mask layers still exist between the laterally grown purer III-V layer and silicon. In a modified ELOG method called corrugated epitaxial lateral overgrowth (CELOG) method, it is possible to obtain direct interface between the III-V layer and silicon. In this presentation we exemplify some recent results obtained by these techniques. We assess the potentials of these methods along with the other existing methods for realizing truly monolithic photonic integration on silicon and III-V/Si heterojunction solar cells.

  • 78.
    Lourdudoss, Sebastian
    et al.
    KTH, Superseded Departments, Electronics.
    Kjebon, Olle
    KTH, Superseded Departments, Electronics.
    Hydride vapor phase epitaxy revisited1997In: IEEE Journal of Selected Topics in Quantum Electronics, ISSN 1077-260X, E-ISSN 1558-4542, Vol. 3, no 3, p. 749-767Article in journal (Refereed)
  • 79.
    Lourdudoss, Sebastian
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP. KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Kjebon, Olle
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Schatz, Richard
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP. KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Nilsson, Stefan
    Stålnacke, Björn
    Fabrication and analysis of directly modulated 1.55 µm semiconductor lasers of bandwidth up to 30 GHz1997In: 4th Annual meeting of European Research Network of Excellence on the Physics and Technology of Mesoscopic Systems (Phantoms), March 1997, Aachen, Germany, paper D2.11., 1997Conference paper (Refereed)
  • 80.
    Lourdudoss, Sebastian
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Metaferia, Wondwosen
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA. Epiclarus AB, Sweden.
    Manavaimaran, Balaji
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Ferre, S.
    Simozrag, B.
    Carras, M.
    Peretti, R.
    Liverini, V.
    Beck, M.
    Faist, J.
    Hydride vapour phase epitaxy assisted buried heterostructure quantum cascade lasers for sensing applications2015In: QUANTUM SENSING AND NANOPHOTONIC DEVICES XII, 2015, Vol. 9370, article id 93700DConference paper (Refereed)
    Abstract [en]

    Buried heterostructure (BH) lasers are routinely fabricated for telecom applications. Development of quantum cascade lasers (QCL) for sensing applications has largely benefited from the technological achievements established for telecom lasers. However, new demands are to be met with when fabricating BH-QCLs. For example, hetero-cascade and multi-stack QCLs, with several different active regions stacked on top of each other, are used to obtain a broad composite gain or increased peak output power. Such structures have thick etch ridges which puts severe demand in carrying out regrowth of semi-insulating layer around very deeply etched (>10 mu m) ridges in short time to realize BH-QCL. For comparison, telecom laser ridges are normally only <5 mu m deep. We demonstrate here that hydride vapour phase epitaxy (HVPE) is capable of meeting this new demand adequately through the fabrication of BH-QCLs in less than 45 minutes for burying ridges etched down to 10-15 mu m deep. This has to be compared with the normally used regrowth time of several hours, e.g., in a metal organic vapour phase epitaxy (MOVPE) reactor. This includes also micro-stripe lasers resembling grating-like ridges for enhanced thermal dissipation in the lateral direction. In addition, we also demonstrate HVPE capability to realize buried heterostructure photonic crystal QCLs for the first time. These buried lasers offer flexibility in collecting light from the surface and relatively facile device characterization feasibility of QCLs in general; but the more important benefits of such lasers are enhanced light matter interaction leading to ultra-high cavity Q-factors, tight optical confinement, possibility to control the emitted mode pattern and beam shape and substantial reduction in laser threshold.

  • 81.
    Lourdudoss, Sebastian
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. KTH, School of Information and Communication Technology (ICT), Centres, Electrum Laboratory, ELAB.
    Olsson, Fredrik
    KTH, School of Information and Communication Technology (ICT), Centres, Electrum Laboratory, ELAB.
    Barrios, C. A.
    Hakkarainen, Teppo
    KTH, School of Information and Communication Technology (ICT), Centres, Electrum Laboratory, ELAB.
    Berrier, Audrey
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Anand, Srinivasan
    KTH, School of Information and Communication Technology (ICT), Centres, Electrum Laboratory, ELAB. KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Aubert, Amandine
    KTH, School of Information and Communication Technology (ICT), Centres, Electrum Laboratory, ELAB.
    Berggren, Jesper
    KTH, School of Information and Communication Technology (ICT), Centres, Electrum Laboratory, ELAB. KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Broeke, R. G.
    Cao, J.
    Chubun, N.
    Seo, S. -W
    Baek, J. -H
    Aihara, K.
    Pharn, Anh-Vu
    Ben Yoo, S. J.
    Avella, M.
    Jimenez, J.
    Heteroepitaxy and selective epitaxy for discrete and integrated devices2006In: 2006 CONFERENCE ON OPTOELECTRONIC AND MICROELECTRONIC MATERIALS & DEVICES, NEW YORK: IEEE , 2006, p. 309-311Conference paper (Refereed)
    Abstract [en]

    We present first results on heteroepitaxy of InP on silicon on insulator (SOI). We also demonstrate InP nanopillar fabrication by means of selective epitaxy. Selective epitaxy is also exploited to fabricate advanced photonic integrated devices for Optical Code Division Multiplex Access (OCDMA) networking applications.

  • 82.
    Lourdudoss, Sebastian
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Olsson, Fredrik
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Sun, Yanting
    Novel routes in heteroepitaxy and selective area growth for nanophotonics2008In: Quantum Sensing and Nanophotonic Devices V / [ed] Sudharsanan, R; Jelen, C, 2008, Vol. 6900, p. H9000-H9000Conference paper (Refereed)
    Abstract [en]

    Integration of active photonic components on silicon and silicon on insulator (SOI) would be versatile for nanophotonics since CMOS compatible processes are available for fabricating passive devices on Si/SOI. Selective area growth of III-V semiconductors is also attractive for realising periodic structures for nanophotonics. Here we report on the recent results of high quality InP on Si and InP on SOI achieved by means of nanopatterning. MQW structures have been realised on InP/Si and InP/SOI. We would elaborate routes for monolithic integration of active and passive devices for nanophotonics.

  • 83.
    Lourdudoss, Sebastian
    et al.
    KTH, Superseded Departments, Electronics.
    Rodríguez Messmer, E.
    KTH, Superseded Departments, Electronics.
    Kjebon, Olle
    KTH, Superseded Departments, Electronics.
    Landgren, Gunnar
    KTH, Superseded Departments, Electronics.
    Temporally resolved selective regrowth of InP around [110] and [110] mesas1996In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 25, no 3, p. 389-394Article in journal (Refereed)
    Abstract [en]

    Temporally resolved selective regrowth of InP around reactive ion etched [110] and [110] directional mesas is studied by hydride vapor phase epitaxy at the growth temperatures of 600, 650, 685, and 700°C. The regrowth profiles are strikingly different depending upon the mesa orientation. The results are interpreted by invoking the difference in the bonding configurations of these mesas as well as the growth facility in a direction leading to the largest reduction of dangling bonds under the growth conditions. Various emerging planes during regrowth are identified and are {hhl} planes with initial values of l/h ≤ 3 but ≥ 3 as the planarization is approached. Initial lateral growth defined as the growth away from the mesa at half of its height in the very first minute is a decreasing function of temperature when plotted as Arrhenius curves. Such a behavior is attributed to the exothermicity of the reaction and to an enhanced pyrolysis of PH3 to P2. The lateral growth rate is much larger than that on the planar substrate. This should be taken into account when regrowth of a doped layer (e.g. InP:Fe or InP:Zn) is carried out to fabricate a buried heterostructure device since the dopant concentration can be very much lower than the one optimized on the planar substrates.

  • 84. Luryi, Serge
    et al.
    Semyonov, Oleg
    Subashiev, Arsen
    Abeles, Joseph
    Chan, Winston
    Shellenbarger, Zane
    Metaferia, Wondwosen
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Effects of thermal treatment on radiative properties of HVPE grown InP layers2014In: Solid-State Electronics, ISSN 0038-1101, E-ISSN 1879-2405, Vol. 95, p. 15-18Article in journal (Refereed)
    Abstract [en]

    Radiative efficiency of highly luminescent bulk InP wafers severely degrades upon heat treatment involved in epitaxial growth of quaternary layers and fabrication of photodiodes on the surface. This unfortunate property impedes the use of bulk InP as scintillator material. On the other hand, it is known that thin epitaxial InP layers, grown by molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD), do not exhibit any degradation. These layers, however, are too thin to be useful in scintillators. The capability of hydride vapor phase epitaxy (HVPE) process to grow thick bulk-like layers in reasonable time is well known, but the radiative properties of HVPE InP layers are not known. We have studied radiative properties of 21 mu m thick InP layers grown by HVPE and found them comparable to those of best luminescent bulk InP virgin wafers. In contrast to the bulk wafers, the radiative efficiency of HVPE layers does not degrade upon heat treatment. This opens up the possibility of implementing free-standing epitaxial InP scintillator structures endowed with surface photodiodes for registration of the scintillation. (C) 2014 Elsevier Ltd. All rights reserved.

  • 85.
    Manavaimaran, Balaji
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA. Anna Univ, Ctr Crystal Growth, Madras 600025, Tamil Nadu, India.
    Ramesh, R.
    Arivazhagan, P.
    Jayasakthi, M.
    Loganathan, R.
    Prabakaran, K.
    Suresh, S.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Baskar, K.
    Influence of initial growth stages on AlN epilayers grown by metal organic chemical vapor deposition2015In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 414, p. 69-75Article in journal (Refereed)
    Abstract [en]

    AIN layers of thickness of about 2 mu m have been grown with AIN nucleation layers (NLs) on (001) sapphire substrates using metal organic chemical vapor deposition. Increasing the AlN-NL deposition temperature from 850 to 1250 degrees C has been found to have significant effect on the surface morphology and the structural quality of the AIN layers. The surface morphology of the AlN-NLs and the AIN layers has been assessed using atomic force microscopy (AFM). The AM images of the AlN-NLs reveal the coalescence pattern of NLs. AM images of the AlN layers and the in-situ reflectance measurement disclose the surface morphology and the growth pattern of the AIN layers, respectively. Smooth surface with macro-steps and terrace features has been achieved for the AIN layer grown on the NL deposited at 950 degrees C. The structural quality of AIN layers has been studied by high resolution X-ray diffraction and Raman spectroscopy. The screw dislocation density from (002) reflection and the average edge dislocation density from (102), (302) and (100) reflections of the AIN layer on NL deposited at 950 degrees C are estimated to be 9 x 10(7) cm(-2) and 4.4 x 10(9) cm(-2), respectively. Lateral correlation length (L) is calculated from the (114) reciprocal space mapping of the AIN layers and correlated with the edge dislocation density of the AIN layers. Raman E-2 (high) phonon mode indicates compressive strain in the AIN layers grown on the NLs deposited at various temperatures. From this work, it has been inferred that the uniform coalescence of the nucleation islands and the complete coverage of AlN-NL determine the surface morphology and the structural quality of the subsequently grown AIN layers.

  • 86. Messmer, E. R.
    et al.
    Lindstrom, T.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    In situ mesa etching and immediate regrowth in a HVPE reactor for buried heterostructure device fabrication2000In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 210, no 4, p. 600-612Article in journal (Refereed)
    Abstract [en]

    Mesa etching in a hydride vapour-phase epitaxy (HVPE) reactor has been studied. Etched depth. underetching and shape of the mesas have been analysed as a function of partial pressures of active gases (HCl, PPI, and InCl) stripe orientation and etching temperature. The experimental results show that the depth and undercut can be etched independently. We propose qualitative mechanisms for etching each of the emerging crystallographic planes ((0 0 1), ( 1 1 0) and {1 1 1}). In situ mesa etching with immediate regrowth was applied to the fabrication of buried heterostructure Fabry-Perot lasers. No surface contamination due to exposure to ambient and low process time are advantages of this technique.

  • 87. Messmer, E. R.
    et al.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Analysis of regrowth evolution around VCSEL type mesas2000In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 219, no 3, p. 185-192Article in journal (Refereed)
    Abstract [en]

    Morphological evolution during hydride vapour phase epitaxial regrowth of InP around vertical cavity surface emitting laser type mesas is studied by varying the input InCl partial pressure. The various emerging planes, indices of which are orientation dependent, have been identified and their growth rates measured. The nature of the emerging planes depends on whether (111)A or (111)B plane is formed initially: further growth relies heavily on how well (111)A or (111)B can collaborate with (001) surface. This is explained in terms of crystallographic structure together with the dangling bond approach. Equal planarisation on the orthogonal directions is feasible at lower InCl partial pressures.

  • 88. Messmer, E. R.
    et al.
    Soderstrom, D.
    Hult, P.
    Marcinkevicius, Saulius
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Look, D. C.
    Properties of semi-insulating GaAs: Fe grown by hydride vapor phase epitaxy2000In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 147, no 8, p. 3109-3110Article in journal (Refereed)
    Abstract [en]

    In this paper we analyze GaAs grown by hydride vapor phase epitaxy (HVPE) and doped with four different iron concentrations between 4 X 10(16) and 4.5 X 10(20) cm(-3). From temperature dependent current-voltage measurements we observed the highest resistivity in the lowest doped sample. We also quantified the activation energy. These results together with those of time resolved photoluminescence measurements indicate that in the sample with the lowest Fe concentration, EL2 may be dominant. From the analysis of the time resolved photoluminescence measurements, the intrinsic EL2 concentration and the electron and hole capture cross sections of Fe in GaAs were estimated.

  • 89.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Dagur, Pritesh
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Hu, Chen
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Polycrystalline indium phosphide on silicon using a simple chemical route2013In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 113, no 9, p. 093504-Article in journal (Refereed)
    Abstract [en]

    We describe a simple, aqueous and low thermal budget process for deposition of polycrystalline indium phosphide on silicon substrate. Using stoichiometric indium oxide films prepared from its spin-coated precursor on silicon as an intermediate step, we achieve stoichiometric indium phosphide films through phosphidisation. Both indium oxide and indium phosphide have been characterized for surface morphology, chemical composition, and crystallinity. The morphology and crystalline structure of the films have been explained in terms of the process steps involved in our deposition method. Incomplete phosphidisation of indium oxide to indium phosphide results in the restructuring of the partly unconverted oxide at the phosphidisation temperature. The optical properties of the indium phosphide films have been analyzed using micro photoluminescence and the results compared with those of a homoepitaxial layer and a theoretical model. The results indicate that good optical quality polycrystalline indium phosphide has been achieved. The Hall measurements indicate that the carrier mobilities of our samples are among the best available in the literature. Although this paper presents the results of indium phosphide deposition on silicon substrate, the method that we present is generic and can be used for deposition on any suitable substrate that is flexible and cheap which makes it attractive as a batch process for photovoltaic applications.

  • 90.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Dev, Apurba
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Kataria, Himanshu
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Sun, Yanting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Anand, Srinivasan
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Tommila, Juha
    Pozina, Galia
    Hultman, Lars
    Guina, Mircea
    Niemi, Tapio
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    High quality InP nanopyramidal frusta on Si2014In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 16, no 21, p. 4624-4632Article in journal (Refereed)
    Abstract [en]

    Nanosized octagonal pyramidal frusta of indium phosphide were selectively grown at circular hole openings on a silicon dioxide mask deposited on indium phosphide and indium phosphide pre-coated silicon substrates. The eight facets of the frusta were determined to be {111} and {110} truncated by a top (100) facet. The size of the top flat surface can be controlled by the diameter of the openings in the mask and the separation between them. The limited height of the frusta is attributed to kinetically controlled selective growth on the (100) top surface. Independent analyses with photoluminescence, cathodoluminescence and scanning spreading resistance measurements confirm certain doping enrichment in the frustum facets. This is understood to be due to crystallographic orientation dependent dopant incorporation. The blue shift from the respective spectra is the result of this enrichment exhibiting the Burstein-Moss effect. Very bright panchromatic cathodoluminescence images indicate that the top surfaces of the frusta are free from dislocations. The good optical and morphological quality of the nanopyramidal frusta indicates that the fabrication method is very attractive for the growth of site-, shape-, and number-controlled semiconductor quantum dot structures on silicon for nanophotonic applications.

  • 91.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Gau, Ming-Horng
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Lo, Ikai
    Pozina, Galia
    Hultman, Lars
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Morphological evolution during epitaxial lateral overgrowth of indium phosphide on silicon2011In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 332, no 1, p. 27-33Article in journal (Refereed)
    Abstract [en]

    Epitaxial lateral overgrowth of InP from mesh and line openings on masked InP seed layer on Si(0 0 1) wafer is investigated. Coalescence occurred more rapidly from the mesh openings than from the line openings. Lethargic coalescence in the line openings is attributed to the gradual formation of growth retarding boundary planes in the initial stages of growth. Extended growth leads to complete coalescence in both types of openings. The surface roughness of the coalesced layer is inversely proportional to its thickness. Cathodoluminescence studies on the uncoalesced islands show the emergence of facets with orientation-dependent dopant concentration, but reveal no defects, in contrast to the coalesced regions. The latter are relaxed and their dislocation density deduced from panchromatic cathodoluminescence mapping varies from 6 x 10(6) to 4 x 10(7) cm(-2) depending on the layer thickness; the reduced density at higher thickness indicates partial self annihilation of dislocations. TEM cross-section studies show that most of the threading dislocations originating in the InP seed layer/Si interface are blocked by the mask, but new dislocations are generated. Some of these dislocations are associated with bounding planar defects such as stacking faults, possibly generated during lateral growth across the mask due to unevenness of the mask surface.

  • 92.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Kataria, Himanshu
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Sun, Yan-Ting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Optimization of InP growth directly on Si by corrugated epitaxial lateral overgrowth2015In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 48, no 4, p. 045102-Article in journal (Refereed)
    Abstract [en]

    In an attempt to achieve an InP-Si heterointerface, a new and generic method, the corrugated epitaxial lateral overgrowth (CELOG) technique in a hydride vapor phase epitaxy reactor, was studied. An InP seed layer on Si (0 0 1) was patterned into closely spaced etched mesa stripes, revealing the Si surface in between them. The surface with the mesa stripes resembles a corrugated surface. The top and sidewalls of the mesa stripes were then covered by a SiO2 mask after which the line openings on top of the mesa stripes were patterned. Growth of InP was performed on this corrugated surface. It is shown that growth of InP emerges selectively from the openings and not on the exposed silicon surface, but gradually spreads laterally to create a direct interface with the silicon, hence the name CELOG. We study the growth behavior using growth parameters. The lateral growth is bounded by high index boundary planes of {3 3 1} and {2 1 1}. The atomic arrangement of these planes, crystallographic orientation dependent dopant incorporation and gas phase supersaturation are shown to affect the extent of lateral growth. A lateral to vertical growth rate ratio as large as 3.6 is achieved. X-ray diffraction studies confirm substantial crystalline quality improvement of the CELOG InP compared to the InP seed layer. Transmission electron microscopy studies reveal the formation of a direct InP-Si heterointerface by CELOG without threading dislocations. While CELOG is shown to avoid dislocations that could arise due to the large lattice mismatch (8%) between InP and Si, staking faults could be seen in the layer. These are probably created by the surface roughness of the Si surface or SiO2 mask which in turn would have been a consequence of the initial process treatments. The direct InP-Si heterointerface can find applications in high efficiency and cost-effective Si based III-V semiconductor multijunction solar cells and optoelectronics integration.

  • 93.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Simozrag, B.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA. Epiclarus AB, Sweden .
    Sun, Yan-Ting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Carras, M.
    Blanchard, R.
    Capasso, F.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Demonstration of a Quick Process to Achieve Buried Heterostructure QCL Leading to High Power and Wall Plug Efficiency2014In: LASER TECHNOLOGY FOR DEFENSE AND SECURITY X, 2014, Vol. 9081, p. 90810O-Conference paper (Refereed)
    Abstract [en]

    Together with the optimal basic design, buried heterostructure quantum cascade laser (BH-QCL) with semi-insulating regrowth offers unique possibility to achieve an effective thermal dissipation and lateral single mode. We demonstrate here for the first time realization of BH-QCLs with a single step regrowth of highly resistive (>1x10(8) ohm.cm) semi-insulating InP:Fe in less than 45 minutes in a flexible hydride vapour phase epitaxy process for burying ridges etched down to 10-15 mu m deep both with and without mask overhang. The fabricated BH-QCLs emitting at similar to 4.7 mu m and similar to 5.5 mu m were characterized. 2 mm long 5.5 mu m lasers with ridge width 17-22 mu m, regrown with mask overhang, exhibited no leakage current. Large width and high doping in the structure did not permit high current density for CW operation. 5 mm long 4.7 mu m BH-QCLs of ridge widths varying from 6-14 mu m regrown without mask overhang, besides being spatially monomode, TM00, exhibited WPE of similar to 8-9% with an output power of 1.5 - 2.5 W at room temperature and under CW operation. Thus, we demonstrate a simple, flexible, quick, stable and single-step regrowth process with extremely good planarization for realizing buried QCLs leading to monomode, high power and high WPE.

  • 94.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Simozrag, Bouzid
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA. Epiclarus AB, Sweden.
    Sun, Yanting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Carras, Mathieu
    Blanchard, Romain
    Capasso, Federico
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Demonstration of a quick process to achieve buried heterostructure quantum cascade laser leading to high power and wall plug efficiency2014In: Optical Engineering: The Journal of SPIE, ISSN 0091-3286, E-ISSN 1560-2303, Vol. 53, no 8, p. 087104-Article in journal (Refereed)
    Abstract [en]

    Together with the optimal basic design, buried heterostructure quantum cascade laser (BH-QCL) with semi-insulating regrowth offers a unique possibility to achieve an effective thermal dissipation and lateral single mode. We demonstrate here the realization of BH-QCLs with a single-step regrowth of highly resistive (>1 x 10(8) ohm . cm) semi-insulating InP: Fe in <45 min for the first time in a flexible hydride vapor phase epitaxy process for burying ridges etched down to 10 to 15 mu m depth, both with and without mask overhang. The fabricated BH-QCLs emitting at similar to 4.7 and similar to 5.5 mu m were characterized. 2-mm-long 5.5-mu m lasers with a ridge width of 17 to 22 mu m, regrown with mask overhang, exhibited no leakage current. Large width and high doping in the structure did not permit high current density for continuous wave (CW) operation. 5-mm-long 4.7-mu m BH-QCLs of ridge widths varying from 6 to 14 mu m regrown without mu mask overhang, besides being spatially monomode, TM00, exhibited wall plug efficiency (WPE) of similar to 8 to 9% with an output power of 1.5 to 2.5 W at room temperature and under CW operation. Thus, we demonstrate a quick, flexible, and single-step regrowth process with good planarization for realizing buried QCLs leading to monomode, high power, and high WPE.

  • 95.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Simozrag, Bouzid
    Junesand, Carl
    Sun, Yan-Ting
    Carras, Mathieu
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    A quick and a flexible hydride vapor phase epitaxy process to achieve buried heterostructure quantum cascade lasers2014In: ECS Transactions, Electrochemical Society, 2014, no 17, p. 61-68Conference paper (Refereed)
    Abstract [en]

    BH-QCLs were fabricated with regrowth of semi-insulating InP:Fe in hydride vapor phase epitaxy reactor. Two types of lateral ridge QCL designs were considered: (i) closely spaced ridges with double trenches and (ii) widely and uniformly spaced ridges. The etched depth varies from 6 to 15 μm in the former and 6 to10 μm in the latter. Double trenches of about 14 μm deep take only &lt; 40 minutes to planarize while the same time is needed to planarize about 8 μm deep trenches with uniform ridges. In any case the achieved growth rate is higher by at least one order of magnitude than that can be achieved in MBE and MOVPE. Some fabricated BH-QCLs are characterized and they exhibit spatially monomode (TMoo) laser with an output power of as high as 2.4 W and wall plug efficiency of ∼8-9% at RT under CW operation.

  • 96.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Sun, Yan-Ting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Dagur, Pritesh
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Alternative Approaches in Growth of Polycrystalline InP on Si2014In: 26th International Conference on Indium Phosphide and Related Materials (IPRM), IEEE , 2014, p. 6880571-Conference paper (Refereed)
    Abstract [en]

    III-V semiconductors are suitable for high efficiency and radiation resistant solar cells. However, the high cost of these materials limited the application of these solar cells only for specialty application. High quality polycrystalline III-V thin films on low cost substrate are the viable solutions for the problem. In this work we demonstrate two new approaches to grow polycrystalline InP on Si(001) substrate. (i) A simple chemical solution route which makes use of deposition of In2O3 on Si and its subsequent phosphidisation and (ii) In assisted growth that involves deposition of In metal on Si and subsequent growth of InP from its precursors in hydride vapor phase epitaxy. Both techniques are generic and can be applied to other semiconductors on low cost and flexible substrates.

  • 97.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Sun, Yanting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Pietralunga, Silvia M.
    Zani, Maurizio
    Tagliaferri, Alberto
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Polycrystalline indium phosphide on silicon by indium assisted growth in hydride vapor phase epitaxy2014In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 116, no 3, p. 033519-Article in journal (Refereed)
    Abstract [en]

    Polycrystalline InP was grown on Si(001) and Si(111) substrates by using indium (In) metal as a starting material in hydride vapor phase epitaxy (HVPE) reactor. In metal was deposited on silicon substrates by thermal evaporation technique. The deposited In resulted in islands of different size and was found to be polycrystalline in nature. Different growth experiments of growing InP were performed, and the growth mechanism was investigated. Atomic force microscopy and scanning electron microscopy for morphological investigation, Scanning Auger microscopy for surface and compositional analyses, powder X-ray diffraction for crystallinity, and micro photoluminescence for optical quality assessment were conducted. It is shown that the growth starts first by phosphidisation of the In islands to InP followed by subsequent selective deposition of InP in HVPE regardless of the Si substrate orientation. Polycrystalline InP of large grain size is achieved and the growth rate as high as 21 mu m/h is obtained on both substrates. Sulfur doping of the polycrystalline InP was investigated by growing alternating layers of sulfur doped and unintentionally doped InP for equal interval of time. These layers could be delineated by stain etching showing that enough amount of sulfur can be incorporated. Grains of large lateral dimension up to 3 mu m polycrystalline InP on Si with good morphological and optical quality is obtained. The process is generic and it can also be applied for the growth of other polycrystalline III-V semiconductor layers on low cost and flexible substrates for solar cell applications.

  • 98.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Sun, Yanting
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Pietralunga, SIlvia M.
    Zani, Maurizio
    Tagliaferri, Alberto
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Polycrystalline InP on Si by using In metal assisted growth in hydride  vapor phase epitaxy2014In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550Article in journal (Refereed)
  • 99.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Tommila, J.
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Kataria, Himanshu
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Hu, Chen
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Guina, M.
    Niemi, T.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Selective area heteroepitaxy through nanoimprint lithography for large area InP on Si2012In: Physica Status Solidi. C, Current topics in solid state physics, ISSN 1610-1634, E-ISSN 1610-1642, Vol. 9, no 7, p. 1610-1613Article in journal (Refereed)
    Abstract [en]

    The use of nanoimprint lithography, a low cost and time saving alternative to E-beam lithography, for growing heteroepitaxial indium phosphide layer on silicon is demonstrated. Two types of patterns on 500 nm and 200 nm thick silicon dioxide mask either on InP substrate or InP seed layer on silicon were generated by UV nanoimprint lithography: (i) circular openings of diameter 150 nm and 200 nm and (ii) line openings of width ranging from 200 nm to 500 nm. Selective area growth and epitaxial lateral overgrowth of InP were conducted on these patterns in a low pressure hydride vapour phase epitaxy reactor. The epitaxial layers obtained were characterized by atomic force microscopy, scanning electron microscopy and micro photoluminescence. The growth from the circular openings on InP substrate and InP (seed) on Si substrate is extremely selective with similar growth morphology. The final shape has an octahedral flat top pyramid type geometry. These can be used as templates for growing InP nanostructures on silicon. The grown InP layers from the line openings on InP substrates are ∌ 2.5 Όm thick with root mean square surface roughness as low as 2 nm. Completely coalesced layer of InP over an area of 1.5 mm x 1.5 mm was obtained.The room temperature photoluminescence intensity from InP layers on InP substrate is 55% of that of homoepitaxial InP layer. The decrease in PL intensity with respect to that of the homoepitaxial layer is probably due to defects associated with stacking faults caused by surface roughness of the mask surface. Thus in this study, we have demonstrated that growth of heteroepitaxial InP both homogeneously and selectively on the large area of silicon can be achieved. This opens up the feasibility of growing InP on large area silicon for several photonic applications.

  • 100.
    Metaferia, Wondwosen
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Semiconductor Materials, HMA (Closed 20120101).
    Tommila, J.
    Kataria, Himanshu
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Semiconductor Materials, HMA (Closed 20120101).
    Junesand, Carl
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Semiconductor Materials, HMA (Closed 20120101).
    Sun, Yanting
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Semiconductor Materials, HMA (Closed 20120101).
    Guina, M.
    Niemi, T.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101), Semiconductor Materials, HMA (Closed 20120101).
    Selective area heteroepitaxy of InP nanopyramidal frusta on Si for nanophotonics2013In: Indium Phosphide and Related Materials (IPRM), 2012 International Conference on, IEEE , 2013, p. 81-84Conference paper (Refereed)
    Abstract [en]

    InP nanopyramidal frusta on InP and InP precoated Si substrates were grown selectively from nano-imprinted circular openings in silicon dioxide mask using a low pressure hydride vapor phase epitaxy reactor. The grown InP nanopyramidal frusta, octagonal in shape, were characterized by Atomic Force Microscopy, Scanning Electron Microscopy and Photoluminescence. The growth is extremely selective and uniform over the entire patterned area on both substrates. The measured diagonal of the top surface is 30 nm and 90 nm for the nanopyramidal frusta grown from 120 nm and 300 nm diameter openings, respectively. The size and morphology as well as the optical quality of these pyramidal frusta make them suitable templates for quantum dot structures for nano photonics and silicon photonics.

1234 51 - 100 of 159
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf