OPTOELECTRONIC WORKSHOPS 00 OPTO-ELECTRONICS

The CECOM Center for Night Vision and Electro-OpticsOPTOELECTRONIC WORKSHOPS00OPTO-ELECTRONICS IN IIl-V SEMICONDUCTORS:MATERIALS AND DEVICESMay 3, 1988sponsored jointly byARO-URI Center for Opto-Electronic Systems ResearchThe Institute of Optics, University of Rochester

*UNCLASSIFIEDSECURITY CLASSIFICATIODOF THIS PAGEREPORT DOCUMENTATION PAGEIs. REPORT SECURITY CLASSIFICATION1b. RESTRICTIVE MARKINdS2&. SECURITY CLASSIFICATION AUTHIORITY3. DISTR11UTIO)iIAVAjLABIuTy OF REPORT2b. DECLASE FCATION/OOWWJ6RADING SCHEDULEApproved for public release;distribution unlimited.4. PERFORMING ORGANIZATION REPORT NUMBER(S)5.MONITORING ORGANIZATION REPORT KUMER(S)6a. NAME OF PERFORMING OPCGANIZATION7a. NAME OF MONITORING ORGANIZATION6b. OFFICE SYMBOL(If applicable)University of RochesterU.S6c. ADDRESS (Oty. State, a&d ZIP Code)ryRserhOfc7b. ADDRESS (Cty, State, and ZIP Code)The Insitute of OpticsRochester, NY 14627P. 0. Box 12211Research Triangle Park, NCBe. NAME OF FUNDISPONSORINGORGANIZATION6b. OFFICE SYMBOL(f ipplcbe)O9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBERU. S. Army Research Office19403-?Sc. ADDRESS (City, State, and ZIP Code)27709-2211k6710. SOURCE OF FUNDING NUMBERSP. 0. Box 12211PROGRAMELEMENT NO.27709-2211Research Triangle Park, NCPROJECTNO.KUNO.IONSNN.INO.NOr11. TITLE (Includ SeCurityC alafako)Optoelectronic Workshop III:12. PERSONAL. AUTHOR(S)Gr13a. TYPE OF REPORTOpto-Electronics in IIl-V Semiconductors:and DevicesMaterialsik13ab. TIME COVERED14. DATE OF REPORT (YearMontADayS1.PAGE COUNTFROMTOMay 3, 19881'16. SUPPLEMENTARY NOTATION The view, opinions and/or findings contained in thisreport are thoseITechnicalof hr) auhan17.FIELDIshulda n fficial Deartuent of the Army position,1S. SUBJECT TERMS (Condinu on rewi Nfneceaavy end ilentify by block number)nbef"AcosCOSATI CODESGROUPSUB-GROUWorkshop:III-V Semiconductors:Materials and Devices'9. ABSTRACT (Contu an reve'se If necenaiy and Ident by block number)'T his workshop on pto-Electronics in Ill-V Semiconductors: Materials and Deviceskrepresents the third of a series of intensive academic/ government interactions inthe field of advanced electro-optics, as part of the Army sponsored UniversityResearch initiative., By documenting the associated technology status and dialogueit is hoped that thi\,baseline will serve all interested parties towards providing asolution to high priority Army requirements. Responsible for program andprogram execution areDr. Nicholas George, University of Rochester (ARO-URI) andDr. Rudy Buser, NVEOC.* A--'It f\Lo20. DISTRIBUTION/ AVAELAIUY OF ABSTRACTO3UNCLASSIFIEDJNLIMTED - 0 SAME AS RPT.22a. NAME OF RESPONSIBLE INDIVIDUALNicholas GeorgeDD FORM 1473, B4 MAR121. ABSTRACT SECURITY CLASSIFICATIONC) OTIC USERSUnclassifiedI22b. TELEPH4ONE (include Arts Code)I716-275-241783 APR edition may be used until eidtauted.'AX other editions are obsoWee---122c. OFFICE SYMBOLSECURITY gLSSFICATION OF TIS PAGEUNCLASSIFIED

OPTOELECTRONIC WORKSHOPONOPTO-ELECTRONICS IN IIl-V SEMICONDUCTORSMATERIALS AND DEVICESOrganizer: ARO-URI-University of Rochesterand CECOM Center for Night Vision and Electro-Optics1.INTRODUCTION2.SUMMARY -- INCLUDING FOLLOW-UP3.VIEWGRAPH PRESENTATIONSA.Center for Opto-Electronic Svstems ResearchOrganizer -- Gary WicksOptical Properties and Technologies of III-V MaterialsGary WicksSuperlattice DisorderingSusan Houde-WalterOptical Interactions in Indirect Bandgap:Il-V Semiconductors and SiliconDennis HallIII-V Optoelectronics for Optical Communication.Thomas BrownB.4.CECOM Center for Night Vision and Electro-OpticsOrganizer-- L. N. DurvasulaLIST OF ATTENDEESAccesslon'c rNTIS GRA&IDTIC TABJustifioatlonDi stribut on/Availabllty CodesDistSpeo lal

1.INTRODUCTIONThis workshop on "Opto-Electronics in Ill-V Semiconductors: Materials andDevices" represents the third of a series of intensive academic/ governmentinteractions in the field of advanced electro-optics, as part of the Armysponsored University Research Initiative. By documenting the associatedtechnology status and dialogue it is hoped that this baseline will serve allinterested parties towards providing a solution to high priority Armyrequirements. Responsible for program and program execution areDr. Nicholas George, University of Rochester (ARO-URI) and Dr. Rudy Buser,CCNVEO.

2.SUMMARY AND FOLLOW-UP ACTIONRudy Buser started the workshop with a short talk. He mentioned two areas ofIll-V s which are of interest at NVEOC: 'ocal plane arrays of 10 pm detectors; andmonolithic integration--sources; detectors, etc.Ward Trussel spoke about NVEOC's interest in high power laser diode arrays forYAG pumpingSeveral NVEOC personnel expressed interest in high power/high efficiency visible(green) lasers with good beam quality. One way of doing this is by doubling thediode pumped YAG lasers. Dennis Hall received some intercst when hementioned the possibility of green GaP lasers,George Simonis spoke of interest in optoelectronics at Harry Diamond Labs.Their activities include: doping superlattices for optical modulation; resonanttunneling (mainly theory); piezoreflectance studies of Ill-V heterostructures, andlightwave research for microwave radar applications.The original plan was for L. N. Durvasula and I to get together for a short whileat the end of the workshop to decide how future interactions might proceed.Time did not allow this, however, and we agreed to discuss these items on thephone. I tried several times without success during the week following theworkshop to contact Dr. Durvasula. Finally I sent him a letter stating a fewspecific areas where there appeared to be good overlap between research areasat UR and interests at NVEOC. Also stated in the letter was my feeling that theformal presentation structure was appropriate for the first workshop, butsubsequent interactions should consist of smaller, less formal groups and moredialogue.I would estimate that 30 NVEOC personnel attended the workshop.

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Outfin*Crystal growth technologies*Bulk materials properties*Properties of quantum wells and superlattices*Device fabrication technologies

ENERGY GAP (in eV and /im) VERSUS LATTICECO.NSTANT AT 300K FOR COMPOUND SEMICONDUCTORS.0ZnSeAlP0.5.0-1n:Si00eG -25.45.65.86.0a0 (A)6.26.410-H6.6

Heterojunction Energy Bands* jjjujd ConductionOoeeo Ban dAECEA Gaasasadsa

Quantum WellT na a Iz n ZAMGaAsGaAsEANGaAsSuperlattice (type 1)

Important Epitaxiol StructuresLosersDouble Heterostructure (DH)p GaAsp AlGoAsGaAsn AIGoAsn GaAsAl concentration121,m0.2,&Lmmb121mGraded refractive index-Al concentrationseparate confinementheterostructure (GRINSCH)p GaAsp AIGaAsgroded AIGoAsn AIGoAsn GaAsOther Versionsmulti-quantum wellconstant composition, seporaiconfinement heterostructure

Ill-V Materials for Lasersx 2.2 A m -GaInAsSb/AIGaAsSb DH* 1.7x'-1.2 Am GaInAsPAnP DHx 1.2 -0.9 A m-pseudomorphicGaInAs/AIGaAs OW's* X 0.9 0.68 Am - AIxGaj-xAs/AIyGai 1yAs OW'se x 0.65 pm-Gajswtn.48P/AIGaInP

IIl-V's for Long WavelengthPhotodetectors@Lowest bandgap bulk Ill-V is InAs Sb6 leStrained InAsSb Quantum Wellsx, 12 pm*Intraband transitions in the conduction band ofsuperlattices2 A/Watx 10 pmnote: only radiation polarized along growth axis isdetected

Crystal G rowh Tech noI*Bulk Growth Techniques-Bridgeman-Uquid Encapsulated Czochralski (LEC)9Epitaxial Growth Techniques-Uquid Phase Epitaxy (LPE)-Vapor Phase Epitaxy (VPE)-Molecular Beam Epitaxy (MBE)-Metal Organic Chemical Vapor Deposition (MOCVD)

VAPOR PHASE EPITAXYGociAsC3Go2As2 A5.HtECIH2--GoAsT T,Chloilide VPEGHCIHyrdVEHCH-2,GoHa-Hydride VPEGAsT constonthot wllMOCVDMONH3GoAscold wall

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MOLECULAR SEAM EPITAXYCRVOPANELLINOSUBSTRATENEATING fLOCXGGAS WAFEREFFUUSNICELMUTTERCELLSIIIccT[jethea ccoupS00sePOte60S00FL.i tic'.W'oX4AS5P;Nmteia VACUUMcucbl

Mo ciA RBam Eotax (MBE)MAIN ORO TFUSIO CELSSMAM SOUTRCSILED.CHAMBERCHMEMASS SPECAL(LQaD NITONMANIPLATO IISENSTRAjMOEFFUSION .IGCELLE

6as Source MBE SystemMOMBEStandard MBEgrowth chamberDiffusionPump*Pressurecontrol ofqroup V gases*Crack AsHf and PHin same cell

Computer Controlled K- CellsLPUP I I/:3 j(a ,Al, As,Be, Si)CIHAMBER ISOLID SOURCESOptical PortsandREDResidual GasAnalyzerHigh Temperature3" Wafer Track --- '3StageWaer TackCleaningSyatemExpansiono0e-gunDual e-BeamMetallizationResidual GasAnalyzerOptical PortsandNREDCHAMBER # 2GASo(s3P3SURCESTEGa,TEIn,Al, Be, Si)Computer Controlled Gas Sources

DensityofStates2n-1Energy

Electrooptic Effects in Ill-V'sBulk materials - Franz-Keldysh EffectECAEGvA&lOKV/cmShift Absorption Edge * Change refractiv index:An-5 x1O1AElOKV/cm

Electrooptic Effects an HIl 'sQuantum Wells - Excitonic EffectsCase 1. Electric field // Growth axisEcEv*Change shape of potential well 4*shift exciton energy levels 4 shiftabsorption edge #change refracive index.Case 2. Electric field I Growth axis*Field ionize exciton * remove excitonic features from absorptionspectrum 4 change refracive Index.*The excltonic absorption In quantum wells leads to very largeelectroopticeffects:AnA-Fha-5 x 10-2lOKVlcmc -,100 cmlOKVlcm

Edge Emitting LaserEpiv .LayersSubstrate1

Dry Etching Technius optoelectronic Devi*Chemically Assisted Ion Beam Etching Reactive Ion Beam EtchingeReactive Ion EtchingApplications*Integrated lasers no cleaved mirrors*Other integrated devices- lenses- mirrors- modulators

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Experimental:ref:Y. Suzuki and H. Okamoto, J. Elec. Mats. 12,397 (1983)Compare refractive index (dispersion) of bulkAlo.3Gao.oAs to GaAs/AlAs SL's with various barrierthicknesses:38j LE3.7w 3.6,-0.-Et(e-hh)-,,,3.5 "3.4-162,27)w3.3,1.31.41.51.61.7IBPHOTON ENERGY (eV)Note: for a fixed average alloy composition, one canmake large changes in refractive index by tailoringheterostructure dimensions. useful degrees of freedom in device designlaserswaveguides, lenses, modulatorsdetectors

Heterostructures are grown epitaxiallymolecular beam epitaxymetallorganic chemical vapor deposition-,ilayersA)(2-6000GaAs substrateINTEGRATION: grow one structure, use same basematerial for all componentsridge waveguides,define components(e.g.heterostructure lasers) by removing surroundingmaterial (ion beam etching, cleaving, etc.)Disadvantage:scattering, band bending, not planar, etc.Objective: change bandgap and refractive index locallyto define componentsNew Method: smooth abruptness of heterostructureslocally

GALLIUM COC.TC,,0ChfCD.1%A9)co000.4DI

Mixing is enhanced by impurity transportref: W.D. Laildig, et al, Appl. Phys. Lett. 38,776 (1981)MASKED Zn DIFFUSION INTOSLZn2As3Si3N4AlAs/GaAs SLsmall bandgaphigh indexlarge bandgaplow index

Lasers:Use layer mixing to:1) tune emission wavelengthref.: M.Camras, et a!, App!. Phys. Lett, 54y,5637(1983).ECfgl-3s*,-122.0l2hW''ISCW CURRET(A)0 PWl

THIS WORK:lID involves electrically active species use applied electric field more accurate diffusion coefficient measurements improved lateral resolution for component definitionZn diffusion1ginSi diffusion'--- -1gm---

mask edgediffusion dominateddrive in mixing profile;little time for sidewaysdiffusion.field-dominatedUse evaporated source or gettering layer:Zn2As3Si3N4VAlAs/GaAs SLUse to study lID mechanism, fabricate components.

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OPTICAL INTERACTIONS IN INDIRECT BANDGAPIll-V SEMICONDUCTORS AND SILICON"Gallium Phosphide, GaPOptical Emission*SiliconOptical EmissionWaveguides

ENERGY GAP (in eV and /m) VERSUS LATTICEONSTANT AT 300K FOR COMPOUND SEMICONDUCTORSZnSe.0AlP0.5CdSAll bCdTeAISb"Si "IGaAs--GaSb"Ge'20--5.6-110.L IS . 11I.4)-5.86.0a,(A)6.26.46.6

GALLIUM PHOSPHIDE, GaPINDIRECT GAP:IMPURITY--2.27 eV AT T 300K.RELATED i,XPoISOVALENTWITHPHOSPHORUSISOVALENT ( ISOELECTRONIC) IMPURITYGaP: NGaP :BiorISOVALENT ( ISOELECTRONIC ) MOLECULEGaPZn-OorGaP:Cd-O0(Nearest-Neighbor Donor-Acceptor Pair)