GaAs基GaSb異質(zhì)薄膜的分子束外延生長(zhǎng)與性能研究.pdf

1、哈爾濱工業(yè)大學(xué)碩士學(xué)位論文GaAs基GaSb異質(zhì)薄膜的分子束外延生長(zhǎng)與性能研究姓名：熊麗申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：材料物理與化學(xué)指導(dǎo)教師：趙連城20050601篁塵堡三些查耋：!耋堡圭耋堡篁蘭。。AbstractTheheteroepitaxialgrowthofGaSbonGaAssubstratesbymolecularbeamepitaxy(MBE)wasinvestigatedinthisarticleThecrystalstru

2、cture，surfacemorphology，luminescencepropertiesandelectricalpropertiesofGaSbthinfilmshavebeenstudiedbythemeansofdoublecrystalsXraydi倚action(DCXaD)atomicforcemicroscope(AFM)，Hallmeasurements，photoluminescence(PL)andX—rayph

3、otoelectronspec仃oscopy(XPS)DuringtheepitaxialgrowthofGaSb，reflectionhigh—energyelectrondiffraction(RHEED)wasusedtOmonitorthesurfaceofGaSbinsituBymeansofquantitativeanalysisofRHEEDintensityoscillationCuFvesatdifferentgrow

4、thtemperatureanddifferentSb4／Gabeamequivalentpressure(BEPratio)，andtheanalysisofDCXRD，weobtainedthemostoptimizedgrowthconditionofGaSbfilm：瓦。b=500℃，％4=982℃，Tsb=615℃，andV／IIIbeamequivalentpressure(BEP)ratiowas3：1Meanwhile，

5、thegrowthrateandthicknessofGaSbwere100amlhandlumrespectivelybycalculationInordertodecreasethedislocationdensitywhichiscausedbythelatticemismatch(about7％)，lowtemperature(【丁)GaSbisusedasbufferlayerinthisexperimentThisisals

6、ocalledtwo—stepgrowthmethodThebasictechnologicalprocessisasfollows：firstlyGaSbisdepositedasthebuf艷rlayeratlowtemperature(400℃)；andthenthetemperatureisraisodto500℃andtheGaSbepilayerisgrownontheLTOaSbbufferGrowthparameters

7、ofLTGaSbbufferlayerwerestudied，anditwasfoundthattheoptimumgrowthrate，thickness，andV／IIIbeamequivalentpressureratiowere1439rn／h20nmand20respectivelyThedislocationdensityofGaSbepilayerwasdecreasedandthecrystalqualitywasimp

8、rovedeffectivelybyusingthebufferlayerMoreover，itwasinvestigatedthathowtwo—stepgrowthmethodtoaffectthecrystalqualityofGaSbepilayerThemechanismofthree—dimensionnucleationandquasi—twodimensionofbufferlayergrowthwereestablis