中文摘要：

系统研究了纳米量级的多孔SiNx插入层生长位置对高质量GaN外延薄膜性质的影响。高分辨X射线衍射测量结果表明：SiNx插入层生长在GaN粗糙层上能够得到最好的晶体质量。利用测量结果分别计算出了螺位错和刃位错的密度。此外,GaN薄膜的光学、电学性质分别用Raman散射能谱、低温光致发光能谱和霍尔测量的方法进行了表征。实验发现：SiNx插入层的生长位置对GaN薄膜的应变大小基本没有影响;但插入层的位置改变了薄膜中的本征载流子浓度。

英文摘要：

GaN films with SiNx interlayer were grown on sapphire substrates by metal organic chemical vapor deposition.The effect of nanoporous SiNx interlayer growth position on the properties of high-quality GaN epitaxial films was investigated systematically.The high-resolution X-ray diffraction spectra was achieved when a SiNx interlayer was adopted and inserted on a rough GaN layer.The screw and edge dislocation densities have been calculated.The optical and electrical properties of the GaN films were characterized by Raman scattering spectra,low temperature photoluminescence spectra and Hall measurements,etc.The position of the SiNx interlayer has no impact on the strain in GaN films,but the residual carrier concentration changes with the position of the interlayer.