Numerical and experimental investigation of the effect of the solid–liquid interface shape on grown-in defects in a silicon single crystal

Abstract

The demand for grown-in defect-free wafers for high-performance silicon semiconductor devices is significantly increasing. To obtain defect-free crystals, the ratio v/G of the growth rate v to the temperature gradient G in the growth direction near the solid–liquid interface during crystal growth must be kept at a critical value ξcri. Furthermore, ξcri depends on the interface shape, which is interpreted as the change in the diffusion direction of point defects due to the change in the interface shape. In this study, we present a new interpretation based on simulations and experiments, in which ξcri changes due to the effect of the diffusion direction of point defects when the solid–liquid interface shape is convex, as in the conventional interpretation, as well as the effect of thermal stress when it is concave.