Effect of process parameters and crystal orientation on 3D anisotropic stress during CZ and FZ growth of silicon

Simulations of 3D anisotropic stress are carried out in <100> and <111> oriented Si crystals grown by FZ and CZ processes for different diameters, growth rates and process stages. Temperature dependent elastic constants and thermal expansion coefficients are used in the FE simulations. The von Mises stress at the triple point line is ~5-11% higher in <111> crystals compared to <100> crystals. The process parameters have a larger effect on the von Mises stress than the crystal orientation. Generally, the <111> crystal has a higher azimuthal variation of stress along the triple point line (~8%) than the <100> crystal (~2%). The presence of a crystal ridge increases the stress beside the ridge and decreases it on the ridge compared with the round crystal.