Origin of Strain in GaN Thin Films

Publication Type

Conference Paper

LBNL Report Number

LBNL-39853

Abstract

Photoluminescence measurements are used to determine the strain in GaN thin films grown by Molecular Beam Epitaxy. The strain which originates from growth on lattice mismatched substrates and from differences in thermal expansion coefficients is found to be greatly relaxed. Residual strains are shown to depend on the thickness of GaN buffer layers and the III/V flux ration during main layer growth. The results strongly suggest that the residual biaxial strain caused by the post-growth cooling can be modified by the incorporation of point defects during the main layer growth which introduce an additional hydrostatic strain field. The effect allows for strain engineering of GaN crystals.

Conference Name

23rd International Conference on the Physics of Semiconductors

Year of Publication

1996

Conference Location

Singapore

Call Number

LBNL-39853