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

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46cm^3/min的CP_2Mg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8.73×10^(17) cm^(-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。

GaN ∶ Mg films were grown on sapphire by metal-organic chemical vapor deposition.First,the CP_2Mg source flux of delta doped p-type GaN was studied,it is found that,at lower 46cm-3/min CP_2Mg source flux,the crystal quality and conductivity performance can be improved,obtaining higher 8.73×10^17cm^-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 aprepurge 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.