Abstract
Ingot annealing process is indispensable for compound semiconductor single crystals such as GaAs and InP to improve their electric characteristics. One of the technical problems of ingot annealing is increase of dislocation density that affects the performance of electronic devices. A computer code was developed for the dislocation density evaluation of a single crystal during ingot annealing process. A dislocation kinetics model called the Haasen-Alexander-Sumino model was used as a constitutive equation. In this model, creep strain rate is related to the dislocation density, and this model was extended to the multiaxial stress state based on the theory of crystal plasticity. Three-dimensional finite element model was used to take account of crystal anisotropy in elastic constants and specific slip directions. The authors improve the creep constitutive equation to take account of dislocation annihilation. Dislocation density analyses during ingot annealing process were performed for an InP single crystal with 101.6mm in diameter. The distribution and time variation of dislocation density were obtained from this computer code.
