Azman, Adreen and Shuhaimi, Ahmad and Omar, Al-Zuhairi and Kamarundzaman, Anas and Abdul Khudus, Muhammad Imran Mustafa and Ariff, Azharul and Samsudin, M.E.A. and Zainal, Norzaini and Rahman, Saadah Abdul (2018) Metal organic chemical vapor deposition of m-plane GaN epi-layer using a three-step approach towards enhanced surface morphology. Thin Solid Films, 667. pp. 48-54. ISSN 0040-6090, DOI https://doi.org/10.1016/j.tsf.2018.09.052.
Full text not available from this repository.Abstract
Specular m-plane (101¯0) gallium nitride (m-GaN) epi-layer are grown on m-plane (101¯0) sapphire substrates by metal organic chemical vapor deposition using a three-step approach. A two-step approach was used to grow m-GaN buffer layer (BL), while a three-step approach was applied to improve the surface morphology of the top m-GaN epi-layer at high temperature. The three-step approach started with growing m-aluminum nitride nucleation layer with an optimized ammonia flux during the growth of aluminum nitride. Then the temperature was ramped up during the recrystallization step before the m-GaN BL deposition at low-temperature and the growth of m-GaN layer at high-temperature for the final step. Unexpectedly, when ammonia flow was intentionally halted during the recrystallization step, the surface morphology of the BL drastically changed from three- to two- dimensional with an abrupt cross-sectional structure. This in turn facilitated the complete coalescence of the m-GaN layer as revealed by field emission scanning electron microscopy. The three-step technique was found to affect the quality of m-GaN epi-layer as the samples exhibit improved crystallinity with X-ray diffraction rocking curves widths of 4680 and 1980 arcsec along the azimuth, perpendicular and parallel to [101¯0] directions, respectively.
| Item Type: | Article |
|---|---|
| Funders: | Postgraduate Research Grant (PPP) project no: PG117-2015B, University Malaya Research Grant (UMRG) project no: RP039A-18AFR, Ministry of Higher Education (MOHE) for the financial support under Long Term Research Grant (LRGS) project no: LR001A-2016A |
| Uncontrolled Keywords: | Cross-sectional structures; Field emission scanning electron microscopy; GaN buffer layers; Low temperatures; Nucleation layers; Sapphire substrates; Three-step approach; Two-step approach |
| Subjects: | Q Science > Q Science (General) Q Science > QC Physics |
| Divisions: | Faculty of Science > Department of Physics |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 18 Sep 2019 02:12 |
| Last Modified: | 18 Sep 2019 02:12 |
| URI: | http://eprints.um.edu.my/id/eprint/22400 |
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