Study of the Influence of Surface Cleaning Process on SiGe Epitaxy Particle Defects

Selective SiGe epitaxy was widely used as source/drain process to enhance hole mobility and PMOS device performance. However, the surface treatment of Si substrate is very important before SiGe film growth. Insufficient surface cleaning can cause abnormal growth of SiGe epitaxy films. Tiny particle defects are one of the most common issues in selective epitaxy process and usually caused by the low selectivity process parameters. However, surface cleaning before SiGe deposition can also result in particles and these defects can bring serious yield loss. In this paper, we studied the influence of wet cleaning process on SiGe tiny particles and the optimal surface treatment method for SiGe growth was provided.