Transmission Electron Microscopy Study of a Defected Zone in GaN on a SiC Substrate Grown by Hydride Vapor Phase Epitaxy

Published

August 1, 2003

Author(s)

Leonid A. Bendersky, Denis Tsvetkov, Y Melnik

Abstract

A defected zone in the HVPE (hydride vapor phase epitaxy)-deposited GaN located near an interface with a SiC substrate was investigated by transmission electron microscopy (TEM). It was shown that the defected zone is formed during the process of coalescence and overgrowth of three-dimensional nucleated islands. Formation and morphology of the islands were inferred from the analysis of moir fringes and HRTEM images of stacking fault-type boundaries in the DZ. The islands differ by a non-equivalent translation with respect to the reference (substrate) lattice, and therefore their coalescence results in the formation of stacking fault-type boundaries. For the processing conditions used in the direct HVPE deposition, we suggest that the islands adapt a shape of {112I}-faceted truncated pyramids. Continued coalescence and overgrowth of the crystallographically non-equivalent grains result in a substructure of connected (0001) and {1120} stacking faults and threading dislocations. A density of these defects decreases as the growth of GaN progresses, thus determining the thickness of the defected zone. The extent of the defected zone depends on nucleation frequency and anisotrphic growth rate of different crystallographic facets.

Citation

Journal of Applied Physics

Volume

94

Issue

No. 3

Pub Type

Journals

Keywords

defects, film growth, GaN, HVPE, TEM

Citation

Bendersky, L. , Tsvetkov, D. and Melnik, Y. (2003), Transmission Electron Microscopy Study of a Defected Zone in GaN on a SiC Substrate Grown by Hydride Vapor Phase Epitaxy, Journal of Applied Physics (Accessed December 26, 2024)