Transition between the 1×1 and surface structures of GaN in the vapor-phase environment
| Autor: | James S. Speck, Paul T. Fini, Anneli Munkholm, Jeffrey A. Eastman, G. B. Stephenson, S. P. DenBaars, Orlando Auciello, Carol Thompson |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Phase transition
Materials science Condensed matter physics Scattering Chemical vapor deposition Partial pressure Condensed Matter Physics Molecular physics Electronic Optical and Magnetic Materials Crystal Phase (matter) Metalorganic vapour phase epitaxy Electrical and Electronic Engineering Surface reconstruction |
| Zdroj: | Physica B: Condensed Matter. 283:217-222 |
| ISSN: | 0921-4526 |
| Popis: | Out-of-plane structures of the GaN (0 0 0 1) surface in the metal-organic chemical vapor deposition (MOCVD) environment have been determined using in situ grazing-incidence X-ray scattering. We measured 11 2 l crystal truncation rod intensities at a variety of temperatures and ammonia partial pressures on both sides of the 1×1 to ( 3 ×2 3 ) R 30° surface phase transition. The out-of-plane structure of the ( 3 ×2 3 ) R 30° phase appears to be nearly independent of temperature below the transition, while the structure of the 1×1 phase changes increasingly rapidly as the phase transition is approached from above. A model for the structure of the 1×1 phase with a partially occupied top Ga layer agrees well with the data. The observed temperature dependence is consistent with a simple model of the equilibrium between the vapor phase and the surface coverage of Ga and N. In addition, we present results on the kinetics of reconstruction domain coarsening following a “quench” into the ( 3 ×2 3 ) R 30° phase field. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect