硅中注入硼的异常扩散

<正> 浅结制备是超大规模集成电路发展的关键技术之一。硅中硼、磷等杂质注入,在退火时发生异常扩散,使浅结的控制困难。异常扩散是一个瞬态快速扩散过程。对于硼,在退火开始时,杂质分布尾部推移极快,随之减慢,恢复正常扩散。这一过程用衰变时间表征。

Anomalous Diffusion of Implanted Boron in Silicon

The anomalous diffusion of implanted boron into silicon during rapid thermal annealing has been observed by varying the boron dose, a relative position of boron profile and damage distribution produced by self-implantation at various energies. The experimental results show that anomalous diffusion originates from the point defects induced by implantation. In a heavily damaged region, the extended defects acting as sinks for the point defects retard the anomalous diffusions for a prolonged annealing they begin to be dissolved and to release the point defects suppprting the anomalous diffusion.