多晶硅发射区中的少数载流子注入理论

本文提出了一种新的多晶硅发射区少数载流子注入理论.考虑了晶粒间界厚度和其中的少数载流子复合,假设晶粒间界和晶粒具有不同的少数载流子迁移率和寿命.引入少数载流子迁移率和寿命随多晶硅厚度变化的函数,通过求解与单晶硅少数载流子注入形式上完全相同的连续性方程,不仅得到了前人关于晶粒间界对少数载流子具有阻碍和复合双重作用的结论,而且成功地区分了不同晶粒间界对降低注入饱和少数载流子电流贡献的大小.其中,第一个晶粒间界能够最有效地减少注入饱和少数载流子电流.与此同时,本文还得到了能够降低注入饱和少子电流百分之十以上的有效晶粒间界个数与晶粒/晶粒间界界面态密度和晶粒大小之间的关系.

Theory about Minority Carrier Injection into Polysilicon Emitter

A new theory about minority carrier injection into polysilicon emitter has been proposed in this paper. The minority carrier recombination in grain boundary and its width are considered. The functions of minority carrier mobility and lifetime as polysilicon width are introduced. Not only the conclusion that grain boundary blocks and recombines minority carrier is obtained,but the contribution of different grain boundaries to injecting saturate minority carrier current is distingnished successfully. The injecting saturate minority carrier current may be reduced the most effectively by the first grain boundary. Meanwhile,the relationship between the number of effective grain boundaries, which reduce injecting saturate minority carrier current more than ten percent,and the interfacial state density of grain boundary and grain size has also been presented.