Homoepitaxial growth of GaN under Ga-stable and N-stable conditions by plasma-assisted molecular beam epitaxy
Tarsa, E. J. ; Heying, B. ; Wu, X. H. ; Fini, P. ; DenBaars, S. P. ; Speck, J. S.
[S.l.] : American Institute of Physics (AIP)
Published 1997
[S.l.] : American Institute of Physics (AIP)
Published 1997
| ISSN: |
1089-7550
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| Source: |
AIP Digital Archive
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| Topics: |
Physics
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| Notes: |
The structure, morphology, and optical properties of homoepitaxial GaN layers grown by molecular beam epitaxy on metalorganic chemical vapor deposition (MOCVD)-grown GaN "template" layers were investigated as a function of the group III/group V flux ratio during growth. GaN layers grown with a low III/V ratio (N-stable growth) displayed a faceted surface morphology and a tilted columnar structure with a high density of stacking faults. In contrast, films grown with a high III/V ratio (Ga-stable growth) displayed comparable structure to the underlying MOCVD-grown template. The transition from N-stable to Ga-stable growth modes was found to occur over a narrow range of Ga fluxes at a growth temperature of 650 °C. Evidence of Ga accumulation and step-flow growth was observed for films grown under Ga-stable conditions, leading to the formation of spiral growth features at the surface termination of mixed edge/screw dislocations. Photoluminescence measurements indicate that the deep-level (∼550 nm) emission is increased relative to the near-band edge emission for films grown under N-stable conditions. © 1997 American Institute of Physics.
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| Type of Medium: |
Electronic Resource
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| URL: |