Measurement and empirical equation of critical stresses for slip generation from oxide precipitates in silicon wafers

The behavior of slip dislocations generated from oxide precipitates or bulk microdefects (BMDs) in Czochralski silicon wafers with different BMD sizes and oxygen concentrations has been studied using three-point bending tests at high temperatures (700–850 °C). We have developed a method of measuring critical stresses for slip generation caused by BMD growth. It has been found that not only the locking effect of residual oxygen on dislocations but also other factors such as BMD size are important for critical stress to generate and mobilize slip dislocations on {111} crystallographic planes, especially in high temperature ranges. An empirical equation for the estimation of the critical stress has also been produced using a simple model and the experimental results obtained in this study. The formulation enables us to accurately estimate the behavior of slip deformation under various thermal stress conditions.