Influence of V/III growth flux ratio on trap states in m-plane GaN grown by ammonia-based molecular beam epitaxy
- Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)
- Department of Materials, University of California, Santa Barbara, California 93106-5050 (United States)
Deep level transient spectroscopy (DLTS) and deep level optical spectroscopy (DLOS) were utilized to investigate the behavior of deep states in m-plane, n-type GaN grown by ammonia-based molecular beam epitaxy (NH{sub 3}-MBE) as a function of systematically varied V/III growth flux ratios. Levels were detected at E{sub C} - 0.14 eV, E{sub C} - 0.21 eV, E{sub C} - 0.26 eV, E{sub C} - 0.62 eV, E{sub C} - 0.67 eV, E{sub C} - 2.65 eV, and E{sub C} - 3.31 eV, with the concentrations of several traps exhibiting systematic dependencies on V/III ratio. The DLTS spectra are dominated by traps at E{sub C} - 0.14 eV and E{sub C} - 0.67 eV, whose concentrations decreased monotonically with increasing V/III ratio and decreasing oxygen impurity concentration, and by a trap at E{sub C} - 0.21 eV that revealed no dependence of its concentration on growth conditions, suggestive of different physical origins. Higher concentrations of deeper trap states detected by DLOS with activation energies of E{sub C} - 2.65 eV and E{sub C} - 3.31 eV in each sample did not display measureable sensitivity to the intentionally varied V/III ratio, necessitating further study on reducing these deep traps through growth optimization for maximizing material quality of NH{sub 3}-MBE grown m-plane GaN.
- OSTI ID:
- 22080480
- Journal Information:
- Applied Physics Letters, Vol. 101, Issue 15; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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