zno和aln薄膜mocvd生长及其性质分析-mocvd growth and property analysis of zno and aln thin films.docx

本文共分6章：第一章，主要介绍了ZnO、AlN材料的基本性质，应用前景和研究现状。对主要的薄膜制备和表征手段进行了概述。提出了本文的工作要点。第二章，研究了采用不同进气模式下生长的ZnO薄膜的结晶和发光性质。分析了锌源浓度的提高对ZnO薄膜的生长和发光的影响。第三章，研究了生长条件对薄膜性质的影响并对生长条件进行了一系列优化，最终在高锌源浓度气氛中制备了具有较强的紫外发光强度和单一c轴择优取向的ZnO薄膜。第四章，通过改变锌氧源流量比、生长温度、热处理温度，进一步研究了ZnO薄膜本征缺陷与其发光性质尤其是紫外发光性质的联系。结果证明了：ZnO的紫外发光是自由激子与Zni缺陷共同作用的结果。第五章，利用RF辅助MOCVD方法制备了a轴择优取向的AlN薄膜，对样品分析结果表明：更高的基片温度有利于AlN薄膜的生长；而在一定范围内提高载气流量和RF裂解功率能够提高薄膜的质量，但过高的载气流量和裂解功率均对薄膜的生长产生不良影响。尝试了ZnO/AlN/Si异质结构的生长和特性研究。第六章，总结与展望。关键词：金属有机化学气相外延；氧化锌；氮化铝；锌填隙；光致发光AbstractZnOisaII-VIcompoundwidebandgapsemiconductor.Atroomtemperature,ZnOhasabandgapof3.3eVandtheexcitonbindingenergyof60meV,whichmakestheapplicationinthefieldofoptoelectronicdevicesofZnOisveryoptimisticinthefuture.ZnOperformssomebetterpropertiesthanGaN,suchas:ahigherbandgapandexcitonbindingenergy,whicharehelpfultoimprovetheluminousintensityofthedevice,componentofhighabundanceofelementsandlowcost,thesefactorsmakeZnOhasbecomeapowerfulcompetitorofGaNintheoptoelectronicapplicationfields.ZnOphotoelectricmaterialshavebecomeanewhotspotofresearches.Inthefuturedevelopment,ZnO-basedoptoelectronicdevicesislikelytoreplaceorpartialreplaceGaNdevices.ButtheresearchofZnO-basedoptoelectronicmeetsthebottleneck,inthegrowthofZnOcrystalthecontrolofimpuritiesanddefectshasnotbeenabletoachieveabreakthrough.Therefore,Researchersneedtoconductin-depthstudyofZnOcrystalgrowth,aswellaseffectsofimpuritiesanddefectsonmaterialproperties.Consideringthesepointsofviewabove,inthisarticlewetakeaseriesofstudiesonthegrowthandpropertiesofZnOfilm.Thecontentsofthisdissertationarelistedasfollows:Usingwatervaporasoxygensource,diethylzincaszincsource,WestudiedtheeffectsofgrowthconditionsontheZnOfilmepitaxialgrowth.WefoundthatahigherDEZnflowisconducivetoenhancetheUVlightintensityofZnOfilms,butthatwillleadsthegrowthofthin-filmtakesadouble-preferredorientationmode.Inthiscontext,tomaintainahighZn/Omolecularratio,optimizingtheothergrowthconditions,wepreparedZnOfilmswithasinglec-axispreferredorientationandcangeneratestrongUVluminescencesucce