Growth Of High Quality GaN Thin Films By MBE On Intermediate-temperature Buffer Layers
W.K. Fong, C. F. Zhu, B. H. Leung, Charles Surya
The Hong Kong Polytechnic University, Department of Electronic and Information Engineering
This article was received on Monday, October 16, 2000 and
accepted on Wednesday, December 20, 2000. Abstract
We report the growth of high quality GaN epitaxial layers by
rf-plasma MBE. The unique feature of our growth process is that the GaN
epitaxial layers are grown on top of a double layer that consists of an
intermediate-temperature buffer layer (ITBL), which is grown at 690°C
and a conventional low-temperature buffer layer deposited at 500°C. It
is observed that the electron mobility increases steadily with the thickness of
the ITBL, which peaks at 377 cm2V-1s-1 for an
ITBL thickness of 800 nm. The PL also demonstrated systematic improvements with
the thickness of the ITBL. Our analyses of the mobility and the
photoluminescence characteristics demonstrate that the utilization of an ITBL
in addition to the conventional low-temperature buffer layer leads to the
relaxation of residual strain within the material resulting in improvement
in the optoelectronic properties of the films. A maximum electron mobility of
430 cm2V-1s-1 can be obtained using this
technique and further optimizing the growth conditions for the low-temperature
buffer layer.Outline
Linked Pages
Cite this article as: MRS Internet J. Nitride Semicond. Res. 5, 12(2000).
last updated Wednesday, December 20, 2000 6:07:14 PM.© 2000 The Materials Research Society
