Improved heteroepitaxial MBE GaN growth with a Ga metal buffer layer
Conference
·
OSTI ID:789120
- LBNL Library
We demonstrate that the use of pure gallium (Ga) as a buffer layer results in improved crystal quality of GaN epilayers grown by plasma-assisted molecular beam epitaxy on c-plane sapphire. The resulting epilayers show electron Hall mobilities as high as 400 cm 2 /Vs at a background carrier concentration of 4 x 10 17 cm -3 , an outstanding value for an MBE-grown GaN layer on sapphire. Structural properties are also improved; the asymmetric (101) X-ray rocking curve width is drastically reduced with respect to that of the reference GaN epilayer grown on a low-temperature GaN buffer layer. Nitrided Ga metal layers were investigated for different Ga deposition time. These layers can be regarded as templates for the subsequent Ga main layer growth. It was found that there is an optimum Ga metal layer deposition time for improving the electron mobility in the epilayer. Heating of the Ga metal layer to the epilayer growth temperature under nitrogen plasma is found to be sufficient to produce highly oriented GaN crystals. However, nonuniform surface morphology and incomplete surface coverage were observed after nitridation of comparatively thick Ga metal layers. This is shown to be the reason for the decreasing electron mobility of the epilayers as the Ga metal layer thickness exceeds the optimum value.
- Research Organization:
- Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE Director, Office of Science. Office of Basic Energy Studies. Division of Materials Sciences (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 789120
- Report Number(s):
- LBNL--45958
- Country of Publication:
- United States
- Language:
- English
Similar Records
The effect of the buffer layer on the structure, mobility and photoluminescence of MBE grown GaN[Molecular Beam Epitaxy]
Elastic strain relief in nitridated Ga metal buffer layers for epitaxial GaN growth
GaN thin films by growth on Ga rich GaN buffer layers
Conference
·
Sat Jul 01 00:00:00 EDT 2000
·
OSTI ID:20104544
Elastic strain relief in nitridated Ga metal buffer layers for epitaxial GaN growth
Journal Article
·
Sun Feb 11 23:00:00 EST 2001
· Applied Physics Letters
·
OSTI ID:40205278
GaN thin films by growth on Ga rich GaN buffer layers
Journal Article
·
Sat Jul 01 00:00:00 EDT 2000
· Journal of Applied Physics
·
OSTI ID:834298