Effect of thermal stress on point defect behavior during single crystal Si growth

Abstract

Silicon devices currently require silicon wafers that are free of grown-in defects. Point-defect simulation for silicon crystal growth, which is performed using the advection-diffusion equation considering the pair annihilation of vacancies and self-interstitials, is improved in this study by considering the effect of thermal stress during the growth process. This effect is introduced into the point-defect simulation as the stress term of the formation enthalpy. The stress coefficients in the stress term are determined by analyzing the correlation between the grown-in defect patterns obtained from the actual pulling tests and simulations. The defect patterns obtained from the simulations performed using the improved point-defect simulation method in this study were congruent with the experimental results, particularly for crystals with large diameters and high stress. The improved simulation method proposed in this study shall be useful for designing new hot-zone conditions and enhancing the understanding of point-defect behavior.