Transmission electron microscopy studies of {GaN/γ-LiAlO_1tn2 [GaN/gamma-LiAlO2] heterostructures [Elektronische Ressource] / von Tian-Yu Liu

TransmissionelectronmicroscopystudiesofGaN/γ LiAlO heterostructures2DISSERTATIONzurErlangungdesakademischenGradesdoctorrerumnaturalium(Dr.rer.nat.)imFachPhysikeingereichtanderMathematisch NaturwissenschaftlichenFakult at¨ IHumboldt Universit at¨ zuBerlinvonHerrnM.Sci.Tian YuLiugeborenam31.Juli1974inVRChina¨ ¨PrasidentderHumboldt Universit atzuBerlin:Prof.Dr.Jur¨ genMlynekDekanderMathematisch NaturwissenschaftlichenFakult at¨ I:Prof.Dr.MichaelLinscheidGutachter:1. Prof.Dr.KlausH.Ploog2. Prof.Dr.WolfgangNeumann3. Prof.Dr.WolfgangJager¨eingereichtam: 17.Dezember2003Tagdermundlichen¨ Prufung:¨ 1.Oktober2004AbstractIn this work the structure of (1100)M plane GaN epitaxially grown on γ LiAlO (100) by using plasma 2assistedmolecularbeamepitaxy(PAMBE)isstudied. Theheteroepitaxialalignmentandthemicrostruc tureofM planeGaNaswellasthedefectformationinthelayeraresystematicallyinvestigatedbyusingtransmissionelectronmicroscopy(TEM).GaNiswellknownasoptoelectronicmaterialwhichcontainsallkindsofcrystaldefectsinitsepilayers.Threadingdislocations(TD)andplanardefectsarethecommonextendeddefecttypeswhicharedetectedin epitaxially grown GaN layers in the [0001] orientation. These defects if crossing the active layer doaffect the optical or electrical properties in the GaN based semiconductor materials.