预非晶化硅中注入硼的异常扩散

预非晶化硅中,在非晶区和损伤区之间有一重损伤层存在,其边缘清楚,厚度约为20nm,包含有大量的扩展缺陷。它阻挡了尾部损伤区内簇团分解放出的硅间隙原子向非晶区扩散,大大削弱了非晶区内注入硼的异常扩散。选用条件适当的二次硅离子注入,使重损伤层加重加厚,从而完全阻止了非晶层内硼的异常扩散。本文在实验上为重损伤层阻止非晶区内硼异常扩散的模型提供证明。

Anomalous Diffusion of Implanted Boron in Preamorphized Silicon

Near the amorphous-crystal interface in preamorphized silicon, there is a heavily damagedlayer of about 20 nm thick containing a lot of extended defects.The layer retards the diffusionof excess interstitials into the amorphous region coming from the tail damaged region,where interstitials is supersaturated due to dissolutior of the clusters.Therefore, the anomalousdiffusion of boron is greatly reduced. The anomalous diffusion can he eliminated if the thicknessof the heavily damaged layer is increased by secondary silicon implantation at properconditions.We have provided for the first time an experime(?)tal evidence for the model ofretardation of the boron anomalous diffusion in the preamorphized region.