重掺杂n型GaN材料特性研究  

Investigation on Characteristics of Heavy Si-doping GaN Grown by MOCVD

作　　者：张云龙[1] 韩军[1] 邢艳辉[1] 郭立建[1] 王凯[1] 于保宁 

机构地区：[1]北京工业大学光电子技术省部共建教育部重点实验室,北京100124

出　　处：《半导体光电》2016年第4期499-504,共6页Semiconductor Optoelectronics

基　　金：国家自然科学基金项目(61204011;11204009);北京市自然科学基金项目(4142005);北京市教委能力提升项目(PXM2014_014204_07_000018)

摘　　要：采用金属有机化合物气相外延方法制备了不同SiH_4流量下重掺杂n型GaN材料,研究发现在SiH_4流量为20cm^3/min时样品获得较高的电子浓度,达到6.4×10^(19) cm^(-3),同时材料的结晶质量较好。光荧光测试发现重掺杂使GaN材料的杂质能带进入导带形成带尾态,使带边峰变得不尖锐,并且发现SiH_4流量以及材料的刃位错密度与黄光带发光有关。采用Delta掺杂方式生长的重掺杂样品,样品表面粗糙度降低,晶体质量明显改善,但黄光带发光强度增强。缺陷选择性腐蚀研究发现Delta掺杂方式主要通过降低螺位错密度来改善晶体的质量。Heavy Si-doping GaN on sapphire metalorganic chemical vapor deposition （MOCVD）. under different Sill4 flux was grown by Hall effect measurement results show that electron concentration of the sample in 20 cm^3/min Sill4 gets to a high level of 6.4 × 10^19 cm^-3 , and the crystallization quality measured by XRD is better at the same time. The photoluminescence results indicate that heavy Si-doping condition makes impurity band enter in conduction band, which makes edge-band peak not sharp, and the Sill4 flux has an effect on the density of edge dislocation and yellow luminescence. When the doping way changes to periocic Si delta-doping, the sample＇s surface roughness reduces and its crystallization quality improves obiously, but the intensity of yellow luminescence enhances. Defect-selective etching demonstates that reducing the screw dislocation density can improve the crystallization quality for Delta- doping.

关 键 词：MOCVD 重掺杂n型GaN 光电特性 缺陷选择性腐蚀 

分 类 号：O484.1[理学—固体物理]