半导体中正电子向表面的扩散  

Diffusion of positrons to surface of semiconductors

作　　者：姜健[1] 周新章[1] 朱洁[1] 龙期威[1] 

机构地区：[1]中国科学院金属研究所,中国科学院国际材料物理中心

出　　处：《核技术》1995年第4期199-202,共4页Nuclear Techniques

基　　金：国家自然科学基金

摘　　要：考虑到半导体中内电场的存在对半无限介质和有限厚度薄膜中的正电子扩散过程，在各种边界条件下，利用δ函数法计算了正电子向表面扩散分数。这些结果为半导体多层复合结构中的慢正电子束实验结果的分析提供了理论基础。In this paper a theoretical study of diffusion of positrons to the surface of semiconductors with an internal electric field was reported. For the semi-infinite medium, by using a radiative boundary condition and δ-function method, the fraction of positrons diffusing back to the surface was calculated. The results are of universal significance. For the film with a thickness d, the fractions of positrons diffusing to the surfaces at x=0 and x=d under an absorbing boundary condition were also calculated with the same method. As d approaches infinity, in both cases of implantation profiles, solutions of the positron diffusion equation for the semi-infinite medium can be obtained. The results can be used to the analysis of experimental data for the overlayer/substrate system which contains one film or leveral films and a semi-infinite medium.

关 键 词：半导体 薄膜 正电子扩散 半无限介质 表面 

分 类 号：O472.1[理学—半导体物理] O484.5[理学—物理]