低源流量Delta掺杂p型GaN外延薄膜的研究

Investigation on Low Source Flux Delta Doped p-GaN Flim Grown by MOCVD

摘要:

利用金属有机物化学气相沉积（MOCVD）技术在蓝宝石衬底上制备了GaN∶Mg薄膜。首先，对Delta掺杂p型GaN的掺杂源流量进行优化研究，研究发现在较低46cm3/min的CP2Mg源流量下，晶体质量和导电性能都有所改善，获得了较高空穴浓度，为8.73×1017cm-3，（002）和（102）面FWHM分别为245和316arcsec。随后，采用XRD、Hall测试、PL以及AFM研究了在生长过程中加入生长停顿对Delta掺杂p型GaN材料特性的影响，发现加入生长停顿后，样品电学特性、光学特性和晶体质量并未得到改善，反而下降。

Abstract:

GaN∶Mg films were grown on sapphire by metal-organic chemical vapor deposition. First, the CP2Mg source flux of delta doped p-type GaN was studied, it is found that, at lower 46cm3/min CP2Mg source flux, the crystal quality and conductivity performance can be improved, obtaining higher 8.73×1017cm-3 hole concentration. XRD FWHM on (002) and (102) plane are 245 and 316 arcsec,respectively. Then, XRD, Hall test, PL and AFM were used to study the effects on delta doped p-type GaN material characteristic when adding a pre-purge step during the growth process, and it is found that electrical, optical properties and crystal quality can not be improved, but decreased, due to the growth interruption.