CAJ | 학술논문

采用自制的立式HVPE设备,在GaN/蓝宝石复合衬底上生长了GaN厚外延膜,利用AFM,SEM,XRD,RBS/Channeling,CL,PL以及XPS等技术分析了厚膜的结构和光学性能.结果表明,外延层表面具有台阶结构,接近以层流生长方式二维生长,一些六角形的坑出现在膜表面,坑区具有很强的发光.腐蚀试验显示EPD仅8×106 cm-2;XRD和RBS/channeling表明GaN膜具有较好的晶体质量;PL结果也证明外延层具有高的质量,出现了尖锐的带边峰,半高宽仅67meV,同时出现了黄带和红外带,这些带的出现可能是由本征缺陷和C,O等杂质引起的.
채용자제적입식HVPE설비,재GaN/람보석복합츤저상생장료GaN후외연막,이용AFM,SEM,XRD,RBS/Channeling,CL,PL이급XPS등기술분석료후막적결구화광학성능.결과표명,외연층표면구유태계결구,접근이층류생장방식이유생장,일사륙각형적갱출현재막표면,갱구구유흔강적발광.부식시험현시EPD부8×106 cm-2;XRD화RBS/channeling표명GaN막구유교호적정체질량;PL결과야증명외연층구유고적질량,출현료첨예적대변봉,반고관부67meV,동시출현료황대화홍외대,저사대적출현가능시유본정결함화C,O등잡질인기적.
Thick GaN films were grown on GaN/sapphire template in a vertical HVPE reactor.Various material characterization techniques,including AFM,SEM,XRD,RBS/Channeling,CL,PL,and XPS,were used to characterize these GaN epitaxial films.It was found that stepped/terraced structures appeared on the film surface,which were indicative of a nearly step-flow mode of growth for the HVPE GaN despite the high growth rate.A few hexagonal pits appeared on the surface,which have strong light emission.After being etched in molten KOH,the wavy steps disappeared and hexagonal pits with {10 (1)0} facets appeared on the surface.An EPD of only 8×106cm-2 shows that the GaN film has few dislocations.Both XRD and RBS channeling indicate the high quality of the GaN thick films.Sharp band-edge emission with a full width at half maximum(FWHM)of 67meV was observed,while the yellow and infrared emissions were also found.These emissions are likely caused by native defects and C and O impurities.