摘要
用透射电子显微镜(TEM)和X射线双晶衍射仪(DCXRD)对在Si(111)衬底上生长的InGaN/GaN多量子阱(MQW)LED外延材料的微结构进行了观察和分析.从TEM高分辨像观察到,在Si和AlN界面处未形成SixNy非晶层,在GaN/AlN界面附近的GaN上有堆垛层错存在,多量子阱的阱(InGaN)和垒(GaN)界面明锐、厚度均匀;TEM和DCXRD进一步分析表明MQW附近n型GaN的位错密度为108cm-2量级,其中多数为b=1/3〈1120〉的刃位错.
The microstructure of an InGaN/GaN multiple quantum well (MQW) LED on Si (111) substrate is characterized using transmission electron microscopy (TEM) and double crystal X-ray diffraction (DCXRD). High-resolution TEM shows that there is no amorphous layer at the AIN/Si interface. However,stacking faults in the GaN film appear close to the GaN/ A1N interface. A very sharp interface between the InGaN and GaN layers reveals the good quality of the MQW material. In addition,TEM and XRD indicate that the dislocation density in the n-GaN layer near the MQW is on the order of 10^8 cm^-2, and the major dislocation is pure edge dislocation (b = 1/3 (1150)).
基金
国家高技术研究发展计划资助项目(批准号:2003AA302160)~~