摘要
使用二次离子质谱分析(SIMS)方法研究了As在碲镉汞分子束外延样品中的扩散系数.获得了在240℃,380℃和440℃温度下As在碲镉汞材料中的扩散系数,并发现它与退火过程中Hg的分压有关,且Hg空位对As的扩散有明显的辅助增强作用.研究表明在低温段的240℃/24～48小时的退火中As的扩散非常有限,对样品中As的浓度分布影响不大,而在高温段380℃/16小时和440℃/30分钟退火中,As扩散较为明显,能使原来的PN突变结变缓.综合比较As杂质的电学激活以及As扩散因素,高温段440℃/30分钟的退火条件较理想.
The diffusion coefficient of As in MBE HgCdTe epilayers was studied by using secondary ion mass spectroscopy (SIMS). The diffusion was investigated at various temperatures of 240degreesC 380degreesC and 440degreesC. It was found that the partial pressure of Hg could influence As diffusion and Hg vacancies in epilayers assisted fast diffusion of As. The As diffusion at a lower temperature of 240degreesC/24 similar to48 hrs was negligibly slow. At a higher temperature of 440degreesC/30 min, the diffusion was obviously fast, which can cause the steep PN junction to become graded. By considering electrical activation of As acceptors and diffusion problem during annealing, an annealing condition of 440degreesC/30 min was found to be optimal.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第1期7-10,共4页
Journal of Infrared and Millimeter Waves
基金
中国科学院知识创新工程资助项目(KGCX2 SWJG 06)
