Modelling dislocation generation in high pressure Czochralski growth of InP single crystals: part I. Construction of a visco-plastic deformation model**A major part of the work was performed when SP was at: Department of Mechanical Engineering, Stony Brook University, Stony Brook, NY 11794, USA.

Abstract

A visco-plastic constitutive model for single crystal InP is proposed and embedded in the ABAQUS finite element software through a user-defined subroutine. The model is a multi-slip generalization of the Alexander–Haasen model, with measures for dislocation densities on each of the known slip systems acting as internal variables. The model is completed and verified through its application to the constant strain rate uni-axial deformation tests and comparison with the experimental data. It is then used to simulate uni-axial deformation tests with different axes of orientation, temperature and strain rates. Multi-slip deformations and high strain rates lead to high dislocation densities, while the temperature has a mixed effect depending on the strain. The model developed here and the insights gained through selected simulations will be used in part II of this paper to study the dislocation development during the growth of single crystal InP in the high pressure Czochralski process.