摘要
在等离子增强化学气相沉积法(PECVD)沉积SiO2和SiNX掩蔽层过程中,分解等离子体中浓度较高的H原子使Mg-受主钝化,同时在p-GaN材料表面发生反应形成浅施主特性的NV+空位。高能量离子轰击造成的材料深能级缺陷增多以及沉积形成致密的SiO2和SiNX材料,阻碍了H原子向外扩散,使H原子在Ni/Au电极与p-GaN的界面处聚集,造成p-GaN近表面附近区域Mg-H络合物密度的提高,空穴浓度急剧下降,导致Ni/Au透明电极I-V特性严重恶化。选择较低的射频功率(15W,13.56MHz)沉积模式,经过适当的退火,可以减小沉积SiO2过程对p-GaN的影响。
The I-V characteristics of the Ni/Au Schottky contacts will get worse after SiO2 and SiNx deposition on p-GaN through PECVD. The main degradation mechanism appears to be the competition between the decreases of the hydrogen passivation of Mg acceptors and the ion-induced deep traps, and the increases of the creation of nitrogen vacancies and the gathering of hydrogen in p-GaN material in the course of PECVD deposition. Ion -induced damage did appear to play a significant role. Influence of PECVD generated SiO2 passivation layers on p-GaN were reduced when using low RF power（15 W, 13.56 MHz） and porforming post annealing.
出处
《红外与激光工程》
EI
CSCD
北大核心
2007年第2期214-218,共5页
Infrared and Laser Engineering
基金
国家科技攻关计划资助项目(2003BA316A01)
