摘要
根据位错理论建立了Si中纯净及掺杂 6 0°位错模型 ,利用Recursion方法计算了Si中纯净及掺杂 6 0°位错这种典型环境下的能量和电子结构 ,由此得出 :N、O杂质在位错区比在非位错区更稳定 ,且O优先偏聚于位错 ,不过当O含量不高时 ,N、O可以同时偏聚于位错 ;在位错芯处原子除受近邻Si原子的作用外 ,还要受到杂质原子的钉扎作用 ,且N的这种作用比O强 ,这就从电子理论上解释了掺杂适量的氮可以提高Si的强度和抗翘曲度的事实 .
A model of pure and doped 60° dislocation in semiconductor material Si is established with elastic theory of dislocation.The calculations of energies and the electronic structures of impurities in 60° dislocation region have revealed important features of the impurity effect.In Si,impurities N,O are more stable in the region with 60° dislocation region than that without dislocation,and oxygen takes up the site in edge dislocation region prior to nitrogen.But when oxygen content is very low,N,O may be in edge dislocation region together.The atom at the core of dislocation interacts with neighbors,and with impurities (N,O) at the same time.The interaction of N with the core atom of dislocation is stronger than that of O.This can explain the fact of Si strength enhancement by doping proper nitrogen from electronic theory.
