Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (10 of 171) Show all publications
Fan, X., Smith, A. D., Forsberg, F., Wagner, S., Schröder, S., Akbari, S. S., . . . Niklaus, F. (2020). Manufacture and characterization of graphene membranes with suspended silicon proof masses for MEMS and NEMS applications. MICROSYSTEMS & NANOENGINEERING, 6(1), Article ID 17.
Open this publication in new window or tab >>Manufacture and characterization of graphene membranes with suspended silicon proof masses for MEMS and NEMS applications
Show others...
2020 (English)In: MICROSYSTEMS & NANOENGINEERING, ISSN 2055-7434, Vol. 6, no 1, article id 17Article in journal (Refereed) Published
Abstract [en]

Graphene's unparalleled strength, chemical stability, ultimate surface-to-volume ratio and excellent electronic properties make it an ideal candidate as a material for membranes in micro- and nanoelectromechanical systems (MEMS and NEMS). However, the integration of graphene into MEMS or NEMS devices and suspended structures such as proof masses on graphene membranes raises several technological challenges, including collapse and rupture of the graphene. We have developed a robust route for realizing membranes made of double-layer CVD graphene and suspending large silicon proof masses on membranes with high yields. We have demonstrated the manufacture of square graphene membranes with side lengths from 7 mu m to 110 mu m, and suspended proof masses consisting of solid silicon cubes that are from 5 mu mx5 mu mx16.4 mu m to 100 mu mx100 mu mx16.4 mu m in size. Our approach is compatible with wafer-scale MEMS and semiconductor manufacturing technologies, and the manufacturing yields of the graphene membranes with suspended proof masses were >90%, with >70% of the graphene membranes having >90% graphene area without visible defects. The measured resonance frequencies of the realized structures ranged from tens to hundreds of kHz, with quality factors ranging from 63 to 148. The graphene membranes with suspended proof masses were extremely robust, and were able to withstand indentation forces from an atomic force microscope (AFM) tip of up to 7000nN. The proposed approach for the reliable and large-scale manufacture of graphene membranes with suspended proof masses will enable the development and study of innovative NEMS devices with new functionalities and improved performances.

Place, publisher, year, edition, pages
NATURE PUBLISHING GROUP, 2020
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-273501 (URN)10.1038/s41378-019-0128-4 (DOI)000528968400001 ()2-s2.0-85083758503 (Scopus ID)
Note

QC 20200520

Available from: 2020-05-20 Created: 2020-05-20 Last updated: 2020-05-20Bibliographically approved
Ribet, F., Wang, X., Laakso, M., Pagliano, S., Niklaus, F., Roxhed, N. & Stemme, G. (2020). Vertical integration of microchips by magnetic assembly and edge wire bonding. MICROSYSTEMS & NANOENGINEERING, 6(1), Article ID 12.
Open this publication in new window or tab >>Vertical integration of microchips by magnetic assembly and edge wire bonding
Show others...
2020 (English)In: MICROSYSTEMS & NANOENGINEERING, ISSN 2055-7434, Vol. 6, no 1, article id 12Article in journal (Refereed) Published
Abstract [en]

The out-of-plane integration of microfabricated planar microchips into functional three-dimensional (3D) devices is a challenge in various emerging MEMS applications such as advanced biosensors and flow sensors. However, no conventional approach currently provides a versatile solution to vertically assemble sensitive or fragile microchips into a separate receiving substrate and to create electrical connections. In this study, we present a method to realize vertical magnetic-field-assisted assembly of discrete silicon microchips into a target receiving substrate and subsequent electrical contacting of the microchips by edge wire bonding, to create interconnections between the receiving substrate and the vertically oriented microchips. Vertical assembly is achieved by combining carefully designed microchip geometries for shape matching and striped patterns of the ferromagnetic material (nickel) on the backside of the microchips, enabling controlled vertical lifting directionality independently of the microchip's aspect ratio. To form electrical connections between the receiving substrate and a vertically assembled microchip, featuring standard metallic contact electrodes only on its frontside, an edge wire bonding process was developed to realize ball bonds on the top sidewall of the vertically placed microchip. The top sidewall features silicon trenches in correspondence to the frontside electrodes, which induce deformation of the free air balls and result in both mechanical ball bond fixation and around-the-edge metallic connections. The edge wire bonds are realized at room temperature and show minimal contact resistance (<0.2 Omega) and excellent mechanical robustness (>168mN in pull tests). In our approach, the microchips and the receiving substrate are independently manufactured using standard silicon micromachining processes and materials, with a subsequent heterogeneous integration of the components. Thus, this integration technology potentially enables emerging MEMS applications that require 3D out-of-plane assembly of microchips.

Place, publisher, year, edition, pages
NATURE PUBLISHING GROUP, 2020
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-271286 (URN)10.1038/s41378-019-0126-6 (DOI)000517590500001 ()2-s2.0-85079738557 (Scopus ID)
Note

QC 20200331

Available from: 2020-03-31 Created: 2020-03-31 Last updated: 2020-03-31Bibliographically approved
Laakso, M., Pagliano, S., Shah, U., Mårtensson, G. E., Stemme, G. & Niklaus, F. (2020). Water in contact with the backside of a silicon substrate enables drilling of high-quality holes through the substrate using ultrashort laser pulses. Optics Express, 28(2), 1394-1408
Open this publication in new window or tab >>Water in contact with the backside of a silicon substrate enables drilling of high-quality holes through the substrate using ultrashort laser pulses
Show others...
2020 (English)In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 28, no 2, p. 1394-1408Article in journal (Refereed) Published
Abstract [en]

Holes through silicon substrates are used in silicon microsystems, for example in vertical electrical interconnects. In comparison to deep reactive ion etching, laser drilling is a versatile method for forming these holes, but laser drilling suffers from poor hole quality. In this article, water is used in the silicon drilling process to remove debris and the shape deformations of the holes. Water is introduced into the drilling process through the backside of the substrate to minimize negative effects to the drilling process. Drilling of inclined holes is also demonstrated. The inclined holes could find applications in radio frequency devices.

Place, publisher, year, edition, pages
Optical Society of America, 2020
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-267818 (URN)10.1364/OE.377256 (DOI)000513232200048 ()2-s2.0-85078512474 (Scopus ID)
Note

QC 20200227

Available from: 2020-02-27 Created: 2020-02-27 Last updated: 2020-03-16Bibliographically approved
Smith, A. D., Li, Q., Vyas, A., Haque, M. M., Wang, K., Velasco, A., . . . Enoksson, P. (2019). Carbon-Based Electrode Materials for Microsupercapacitors in Self-Powering Sensor Networks: Present and Future Development. Sensors, 19(19), Article ID 4231.
Open this publication in new window or tab >>Carbon-Based Electrode Materials for Microsupercapacitors in Self-Powering Sensor Networks: Present and Future Development
Show others...
2019 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, no 19, article id 4231Article in journal (Refereed) Published
Abstract [en]

There is an urgent need to fulfill future energy demands for micro and nanoelectronics. This work outlines a number of important design features for carbon-based microsupercapacitors, which enhance both their performance and integration potential and are critical for complimentary metal oxide semiconductor (CMOS) compatibility. Based on these design features, we present CMOS-compatible, graphene-based microsupercapacitors that can be integrated at the back end of the line of the integrated circuit fabrication. Electrode materials and their interfaces play a crucial role for the device characteristics. As such, different carbon-based materials are discussed and the importance of careful design of current collector/electrode interfaces is emphasized. Electrode adhesion is an important factor to improve device performance and uniformity. Additionally, doping of the electrodes can greatly improve the energy density of the devices. As microsupercapacitors are engineered for targeted applications, device scaling is critically important, and we present the first steps toward general scaling trends. Last, we outline a potential future integration scheme for a complete microsystem on a chip, containing sensors, logic, power generation, power management, and power storage. Such a system would be self-powering.

Keywords
energy storage, IoT, microsupercapacitors, self-powering systems, sensor networks
National Category
Nano Technology Other Electrical Engineering, Electronic Engineering, Information Engineering Energy Engineering
Identifiers
urn:nbn:se:kth:diva-261098 (URN)10.3390/s19194231 (DOI)000494823200175 ()31569477 (PubMedID)2-s2.0-85072778122 (Scopus ID)
Note

QC 20191106

Available from: 2019-10-01 Created: 2019-10-01 Last updated: 2020-03-09Bibliographically approved
Quack, N., Sattari, H., Takabayashi, A. Y., Zhang, Y., Edinger, P., Errando-Herranz, C., . . . Bogaerts, W. (2019). Exploiting Mechanics at the Nanoscale to Enhance Photonic Integrated Circuits. In: 2019 Optical Fiber Communications Conference and Exhibition, OFC 2019 - Proceedings: . Paper presented at 2019 Optical Fiber Communications Conference and Exhibition, OFC 2019; San Diego; United States; 3 March 2019 through 7 March 2019 (pp. 1-3). Institute of Electrical and Electronics Engineers (IEEE), Article ID 8696652.
Open this publication in new window or tab >>Exploiting Mechanics at the Nanoscale to Enhance Photonic Integrated Circuits
Show others...
2019 (English)In: 2019 Optical Fiber Communications Conference and Exhibition, OFC 2019 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2019, p. 1-3, article id 8696652Conference paper, Published paper (Refereed)
Abstract [en]

With the maturing and the increasing complexity of Silicon Photonics technology, novel avenues are pursued to reduce power consumption and to provide enhanced functionality: exploiting mechanical movement in advanced Silicon Photonic Integrated Circuits provides a promising path to access a strong modulation of the effective index and to low power consumption by employing mechanically stable and thus non-volatile states. In this paper, we will discuss recent achievements in the development of MEMS enabled systems in Silicon Photonics and outline the roadmap towards reconfigurable general Photonic Integrated Circuits.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2019
Keywords
integrated optics, silicon photonics, MEMS, reconfigurable photonics
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Nano Technology
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-258915 (URN)2-s2.0-85065483032 (Scopus ID)978-1-943580-53-8 (ISBN)
Conference
2019 Optical Fiber Communications Conference and Exhibition, OFC 2019; San Diego; United States; 3 March 2019 through 7 March 2019
Projects
MORPHIC
Note

QC 20191112

Available from: 2019-09-11 Created: 2019-09-11 Last updated: 2019-12-04Bibliographically approved
Pagliano, S., Gota, F., Raja, S. N., Dubois, V. J., Stemme, G. & Niklaus, F. (2019). Feedback-free electromigrated tunneling junctions from crack-defined gold nanowires. In: Feedback-free electromigrated tunneling junctions from crack-defined gold nanowires: . Paper presented at 32nd IEEE International Conference on Micro Electro Mechanical Systems, Seoul, Korea, from 27-31 January 2019..
Open this publication in new window or tab >>Feedback-free electromigrated tunneling junctions from crack-defined gold nanowires
Show others...
2019 (English)In: Feedback-free electromigrated tunneling junctions from crack-defined gold nanowires, 2019Conference paper, Published paper (Refereed)
Abstract [en]

Tunneling junctions are pairs of electrodes separated by gaps of a few nanometers (< 3 nm) that allow electrons to tunnel across the gap. Tunneling junctions are of great importance for applications such as label-free biomolecule sensing and single molecule electronics, but their fabrication remains difficult and laborious. In this paper, we present a simple 2-stage process for the fabrication of tunneling junctions consisting of electrode pairs made of gold (Au). This is achieved by combining a novel methodology for fabricating crack-defined Au nanowires at wafer-scale with a constant voltage, feedback-free electromigration procedure to form tunneling nanogaps free of debris.

Keywords
tunneling junctions, crack junction, electromigration
National Category
Nano Technology
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-250572 (URN)
Conference
32nd IEEE International Conference on Micro Electro Mechanical Systems, Seoul, Korea, from 27-31 January 2019.
Note

QCR 20190820

Available from: 2019-04-30 Created: 2019-04-30 Last updated: 2019-08-20Bibliographically approved
Pagliano, S., Gota, F., Raja, S. N., Dubois, V. J., Stemme, G. & Niklaus, F. (2019). Feedback-Free Electromigrated Tunneling Junctions from Crack-Defined Gold Nanowires. In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS): . Paper presented at 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS), 27-31 Jan. 2019 (pp. 365-367). IEEE conference proceedings
Open this publication in new window or tab >>Feedback-Free Electromigrated Tunneling Junctions from Crack-Defined Gold Nanowires
Show others...
2019 (English)In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), IEEE conference proceedings, 2019, p. 365-367Conference paper, Published paper (Refereed)
Abstract [en]

Tunneling junctions are pairs of electrodes separated by gaps of a few nanometers that allow electrons to tunnel across the gap. Tunneling junctions are of great importance for applications such as label-free biomolecule sensing and single molecule electronics, but their fabrication remains difficult and laborious. In this paper, we present a simple 2-stage process for the fabrication of tunneling junctions consisting of electrode pairs made of gold (Au). This is achieved by combining a novel methodology for fabricating crack-defined Au nanowires at wafer-scale with a constant voltage, feedback-free electromigration procedure to form tunneling nanogaps free of debris.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2019
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-268311 (URN)10.1109/MEMSYS.2019.8870698 (DOI)2-s2.0-85074354086 (Scopus ID)
Conference
2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS), 27-31 Jan. 2019
Note

QC 20200310

Available from: 2020-03-10 Created: 2020-03-10 Last updated: 2020-03-10Bibliographically approved
Fan, X., Fredrik, F., Smith, A. D., Schröder, S., Wagner, S., Rödjegård, H., . . . Niklaus, F. (2019). Graphene ribbons with suspended masses as transducers in ultra-small nanoelectromechanical accelerometers. Nature Electronics, 2(9), 394-404
Open this publication in new window or tab >>Graphene ribbons with suspended masses as transducers in ultra-small nanoelectromechanical accelerometers
Show others...
2019 (English)In: Nature Electronics, ISSN 2520-1131, Vol. 2, no 9, p. 394-404Article in journal (Refereed) Published
Abstract [eo]

Nanoelectromechanical system (NEMS) sensors and actuators could be of use in the development of next-generation mobile, wearable and implantable devices. However, these NEMS devices require transducers that are ultra-small, sensitive and can be fabricated at low cost. Here, we show that suspended double-layer graphene ribbons with attached silicon proof masses can be used as combined spring–mass and piezoresistive transducers. The transducers, which are created using processes that are compatible with large-scale semiconductor manufacturing technologies, can yield NEMS accelerometers that occupy at least two orders of magnitude smaller die area than conventional state-of-the-art silicon accelerometers. With our devices, we also extract the Young’s modulus values of double-layer graphene and show that the graphene ribbons have significant built-in stresses.

Place, publisher, year, edition, pages
Nature Publishing Group, 2019
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-259517 (URN)10.1038/s41928-019-0287-1 (DOI)000486394600009 ()2-s2.0-85072131685 (Scopus ID)
Note

QC 20191004

Available from: 2019-09-16 Created: 2019-09-16 Last updated: 2019-10-14Bibliographically approved
Enrico, A., Dubois, V. J., Niklaus, F. & Stemme, G. (2019). Manufacturing of Sub-20 NM Wide Single Nanowire Devices using Conventional Stepper Lithography. In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS): . Paper presented at 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS), 27-31 Jan. 2019 (pp. 244-247). IEEE conference proceedings
Open this publication in new window or tab >>Manufacturing of Sub-20 NM Wide Single Nanowire Devices using Conventional Stepper Lithography
2019 (English)In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), IEEE conference proceedings, 2019, p. 244-247Conference paper, Published paper (Refereed)
Abstract [en]

Single nanowires have a broad range of applications in chemical and bio-sensing, photonics, and material science, but realizing individual nanowire devices in a scalable manner remains extremely challenging. This work presents a scalable and flexible method to realize single gold nanowire devices. We use conventional optical stepper lithography to generate notched beam structures, and crack lithography to obtain sub-20-nm-wide nanogaps at the notches, thereby obtaining a suitable shadow mask to define a single nanowire device. Then a gold evaporation step through the shadow mask forms the individual gold nanowires with positional and dimensional accuracy and with electrical contacts to probing pads.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2019
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-268309 (URN)10.1109/MEMSYS.2019.8870647 (DOI)2-s2.0-85074363946 (Scopus ID)
Conference
2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS), 27-31 Jan. 2019
Note

QC 20200310

Available from: 2020-03-10 Created: 2020-03-10 Last updated: 2020-03-10Bibliographically approved
Shi, X., Huang, Z., Laakso, M., Niklaus, F., Sliz, R., Fabritius, T., . . . Cao, W. (2019). Quantitative assessment of structural and compositional colors induced by femtosecond laser: A case study on 301LN stainless steel surface. Applied Surface Science, 484, 655-662
Open this publication in new window or tab >>Quantitative assessment of structural and compositional colors induced by femtosecond laser: A case study on 301LN stainless steel surface
Show others...
2019 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 484, p. 655-662Article in journal (Refereed) Published
Abstract [en]

The topic of durable coloration and passivation of metal surfaces using state-of-the-art techniques has gained enormous attention and devotion with unremitting efforts of researchers worldwide. Although femtosecond laser marking has been performed on many metals, the related coloration mechanisms are mainly referred to structural colors produced by the interaction of visible light with periodic surface structures. Yet, general quantitative determination of the resulting colors and their origins remain elusive. In this work, we realized quantitative separations of structural colors and compositional pigmentary colors on 301LN austenitic stainless steel surfaces that were treated by femtosecond laser machining. The overall color information was extracted from surface reflectance, with structural color given by numerical simulations, and oxide compositions by chemical state analysis. It was shown that the laser-induced apparent colors of 301LN steel surfaces were combinations of structural and compositional colorations, with the former dominating the angular response and the latter setting up the brownish bases. In addition to the quantification of colors, the analysis method in this work may be useful for the generation and specification of tailored color palettes for practical coloration on metal surfaces by femtosecond laser marking.

Place, publisher, year, edition, pages
Elsevier B.V., 2019
Keywords
Compositional color, Femtosecond laser marking, Laser coloration, Structural color, Chemical analysis, Femtosecond lasers, Marking machines, Microalloyed steel, Structural metals, Chemical state analysis, Femtosecond laser machining, Periodic surface structures, Quantitative assessments, Quantitative determinations, Quantitative separation, State-of-the-art techniques, Color
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-252501 (URN)10.1016/j.apsusc.2019.04.147 (DOI)000471830700072 ()2-s2.0-85064510118 (Scopus ID)
Note

Correction in DOI:10.1016/j.apsusc.2019.144583 ISI:000502040600167

QC 20190711. QC 20200115

Available from: 2019-07-11 Created: 2019-07-11 Last updated: 2020-03-10Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-0525-8647

Search in DiVA

Show all publications