1. Multicycle rapid thermal annealing optimization of Mg-implanted GaN: Evolution of surface, optical, and structural properties.
- Author
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Greenlee, Jordan D., Feigelson, Boris N., Anderson, Travis J., Tadjer, Marko J., Hite, Jennifer K., Mastro, Michael A., Eddy Jr., Charles R., Hobart, Karl D., and Kub, Francis J.
- Subjects
THIN films ,OPTICAL properties ,METAL organic chemical vapor deposition ,PHOTOLUMINESCENCE measurement ,ANNEALING of metals ,RAMAN spectroscopy ,ATOMIC force microscopy - Abstract
The first step of a multi-cycle rapid thermal annealing process was systematically studied. The surface, structure, and optical properties of Mg implanted GaN thin films annealed at temperatures ranging from 900 to 1200 °C were investigated by Raman spectroscopy, photoluminescence, UV-visible spectroscopy, atomic force microscopy, and Nomarski microscopy. The GaN thin films are capped with two layers of in-situ metal organic chemical vapor deposition -grown AlN and annealed in 24 bar of N
2 overpressure to avoid GaN decomposition. The crystal quality of the GaN improves with increasing annealing temperature as confirmed by UV-visible spectroscopy and the full widths at half maximums of the E2 and A1 (LO) Raman modes. The crystal quality of films annealed above 1100 °C exceeds the quality of the as-grown films. At 1200 °C, Mg is optically activated, which is determined by photoluminescence measurements. However, at 1200 °C, the GaN begins to decompose as evidenced by pit formation on the surface of the samples. Therefore, it was determined that the optimal temperature for the first step in a multi-cycle rapid thermal anneal process should be conducted at 1150 °C due to crystal quality and surface morphology considerations. [ABSTRACT FROM AUTHOR]- Published
- 2014
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