Change search
ReferencesLink to record
Permanent link

Direct link
Ion beam etching of InP based materials
KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
2001 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Dry etching is an important technique for pattern transferin fabrication of most opto-electronic devices, since it canprovide good control of both structure size and shape even on asub-micron scale. Unfortunately, this process step may causedamage to the material which is detrimental to deviceperformance. It is therefore an objective of this thesis todevelop and investigate low damage etching processes for InPbased devices.

An ion beam system in combination with hydrocarbon (CH4) based chemistries is used for etching. At variousion energies and gas flows the etching is performed in twomodes, reactive ion beam etching (RIBE) and chemical assistedion beam etching (CAIBE). How these conditions affect both etchcharacteristics (e.g. etch rates and profiles, surfacemorphology and polymer formation) and etch induced damage (onoptical and electrical properties) is evaluated and discussed.Attention is also paid to the effects of typical post etchingtreatments such as annealing on the optical and electricalproperties. An important finding is the correlation betweenas-etched surface morphology and recovery/degradation inphotoluminescence upon annealing in PH3. Since this type of atmosphere is typical forcrystal regrowth (an important process step in III/Vprocessing) a positive result is imperative. A low ion energy N2/CH4/H2CAIBE process is developed which not onlysatisfies this criteria but also exhibits good etchcharacteristics. This process is used successfully in thefabrication of laser gratings. In addition to this, the abilityof the ion beam system to modify the surface morphology in acontrollable manner is exploited. By exposing such modifiedsurfaces to AsH3/PH3, a new way to vary size and density of InAs(P)islands formed on the InP surfaces by the As/P exchangereaction is presented.

This thesis also proposes a new etch chemistry, namelytrimethylamine ((CH3)3N or TMA), which is a more efficient methyl sourcecompared to CH4because of the low energy required to break the H3C-N bond. Since methyl radicals are needed for theetching it is presumably a better etching chemistry. A similarinvestigation as for the CH4chemistry is performed, and it is found that bothin terms of etch characteristics and etch induced damage thisnew chemistry is superior. Extremely smooth morphologies, lowetch induced damage and an almost complete recovery uponannealing can be obtained with this process. Significantly,this is also so at relatively high ion energies which allowshigher etch rates.

Keywords:InP, dry etching, ion beam etching, RIBE,CAIBE, hydrocarbon chemistry, trimethylamine, As/P exchangereaction, morpholoy, low damage, AFM, SCM, annealing

Place, publisher, year, edition, pages
Kista: Mikroelektronik och informationsteknik , 2001. , vii, 47 p.
Trita-HMA, ISSN 1404-0379 ; 2001:2
Keyword [en]
InP, dry etching, ion beam etching, RIBE, CAIBE, hydrocarbon chemistry, trimethylamine, As/P exchange reaction, morphology, low damage, AFM, SCM, annealing
URN: urn:nbn:se:kth:diva-3160OAI: diva2:8927
Public defence
NR 20140805Available from: 2001-05-22 Created: 2001-05-22Bibliographically approved

Open Access in DiVA

fulltext(819 kB)3224 downloads
File information
File name FULLTEXT01.pdfFile size 819 kBChecksum SHA-1
Type fulltextMimetype application/pdf

By organisation
Microelectronics and Information Technology, IMIT

Search outside of DiVA

GoogleGoogle Scholar
Total: 3224 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 484 hits
ReferencesLink to record
Permanent link

Direct link