Loading…

Numerical analysis of dislocation density and residual stress in a GaN single crystal during the cooling process

In this study, we investigate the influence of thermal stress on the dislocation density and residual stress in GaN single crystals by numerical analysis. The results show that the dislocation density increases, but the thermal stress does not decrease, and the residual stress increases throughout t...

Full description

Saved in:
Bibliographic Details
Published in:Journal of crystal growth 2017-06, Vol.468, p.839-844
Main Authors: Nakano, S., Gao, B., Kakimoto, K.
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In this study, we investigate the influence of thermal stress on the dislocation density and residual stress in GaN single crystals by numerical analysis. The results show that the dislocation density increases, but the thermal stress does not decrease, and the residual stress increases throughout the cooling process. The reason for this phenomenon is that the dislocation density is higher at the periphery of the crystal and distribution of dislocation density in the crystal is inhomogeneous. Then, the increase of dislocation does not allow the thermal stress on the entire crystal to relax. •We developed an extended 3D HAS model to analyze dislocation and residual stress.•We only consider thermal stress and the effect of lattice mismatch was ignored.•Thermal expansion coefficient for the substrate affects the dislocation density.•The dislocation density rapidly increase at the beginning of the cooling process.•The thermal stress increase due to inhomogeneous distribution of dislocation density.
ISSN:0022-0248
1873-5002
DOI:10.1016/j.jcrysgro.2017.01.034