Optimization of deposition uniformity during silicon epitaxy in deep trenches

摘要

Experimental and theoretical studies as well as the optimization of silicon epitaxy in deep trenches are reported. Detailed measurements of the trench profile as functions of time and trench location on the wafer are performed. Modeling analysis is based on a multiscale approach that accounts for the transport and chemical reactions both in the reactor and in the trenches. Simulations have revealed the mechanism of direct or reverse growth starvation (higher growth rate at the trench top or bottom, respectively) and explain the evolution of the trench shape observed in the experiment. Eventually, the thickness uniformity within the trench and wafer has been considerably improved with the proper choice of process parameters.