Elastic strain relief in nitridated Ga metal buffer layers for epitaxial GaN growth

Gallium nitride epitaxial layers were grown on sapphire by molecular-beam epitaxy using nitridated gallium metal films as buffer layers. The mechanical properties of the buffer layers were investigated and correlated with their chemical composition as determined by synchrotron radiation photoelectro...

Full description

Saved in:
Bibliographic Details
Published in:Applied physics letters 2001-02, Vol.78 (7), p.895-897
Main Authors: Kim, Yihwan, Shapiro, Noad A., Feick, Henning, Armitage, Robert, Weber, Eicke R., Yang, Yi, Cerrina, Franco
Format: Article
Language:English
Subjects:
BUFFERS
CHEMICAL COMPOSITION
GALLIUM NITRIDES
MECHANICAL PROPERTIES
PARTICLE ACCELERATORS
PHOTOELECTRON SPECTROSCOPY
PHOTOLUMINESCENCE
STRAINS
SYNCHROTRON RADIATION
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:Gallium nitride epitaxial layers were grown on sapphire by molecular-beam epitaxy using nitridated gallium metal films as buffer layers. The mechanical properties of the buffer layers were investigated and correlated with their chemical composition as determined by synchrotron radiation photoelectron spectroscopy. Biaxial tension experiments were performed by bending the substrates in a pressure cell designed for simultaneous photoluminescence measurements. The shift of the excitonic luminescence peak was used to determine the stress induced in the main GaN epilayer. The fraction of stress transferred from substrate to main layer was as low as 27% for samples grown on nitridated metal buffer layers, compared to nearly 100% for samples on conventional low-temperature GaN buffer layers. The efficiency of stress relief increased in proportion to the fraction of metallic Ga in the nitridated metal buffer layers. These findings suggest GaN films containing residual metallic Ga may serve as compliant buffer layers for heteroepitaxy.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.1347016