Two-domain formation during the epitaxial growth of GaN (0001) on c-plane Al{sub 2}O{sub 3} (0001) by high power impulse magnetron sputtering

Journal Article · Thu Dec 15 04:00:00 EST 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3671560· OSTI ID:22038815

Junaid, M; Lundin, D; Palisaitis, J; Hsiao, C -L; Darakchieva, V; Jensen, J; Persson, P O. A.; Sandstroem, P; Helmersson, U; Hultman, L; Birch, J ^[1]; Lai, W -J; Chen, L -C ^[2]; Chen, K -H ^[2]

---

1. Department of Physics, Chemistry and Biology (IFM), Linkoeping University, SE-581 83 Linkoeping (Sweden)
2. Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan (China)

We study the effect of high power pulses in reactive magnetron sputter epitaxy on the structural properties of GaN (0001) thin films grown directly on Al{sub 2}O{sub 3} (0001) substrates. The epilayers are grown by sputtering from a liquid Ga target, using a high power impulse magnetron sputtering power supply in a mixed N{sub 2}/Ar discharge. X-ray diffraction, micro-Raman, micro-photoluminescence, and transmission electron microscopy investigations show the formation of two distinct types of domains. One almost fully relaxed domain exhibits superior structural and optical properties as evidenced by rocking curves with a full width at half maximum of 885 arc sec and a low temperature band edge luminescence at 3.47 eV with the full width at half maximum of 10 meV. The other domain exhibits a 14 times higher isotropic strain component, which is due to the higher densities of the point and extended defects, resulting from the ion bombardment during growth. Voids form at the domain boundaries. Mechanisms for the formation of differently strained domains, along with voids during the epitaxial growth of GaN are discussed.

• OSTI ID: 22038815
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 110; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
EV RANGE
GALLIUM NITRIDES
ION BEAMS
NEUTRON DIFFRACTION
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
POINT DEFECTS
RAMAN SPECTRA
SEMICONDUCTOR MATERIALS
SPUTTERING
STRAINS
SUBSTRATES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
VAPOR PHASE EPITAXY
X-RAY DIFFRACTION