Photo-assisted RIE of GaN in BCl{sub 3}/Cl{sub 2}/N{sub 2}
Gallium nitride (GaN) has been under intense investigation due to its unique qualities (wide band gap, chemical and temperature stability) for optoelectronic and high temperature/high power applications. To this end, reactive ion etching (RIE) experiments were performed on GaN thin films using BCl{sub 3}/Cl{sub 2}/Ar. These resulted in etch rates of 1,400 {angstrom}/min at {minus}400 V dc bias. However, rough etched surfaces, nitrogen surface depletion and high chlorine content were observed. In order to remedy these shortcomings, a photo-assisted RIE process using a filtered Xe lamp beam was developed, resulting in higher etch rates but again in nitrogen depleted surfaces. Preliminary results on using nitrogen instead of argon in the process chemistry show a big improvement in photo-assisted etch rates (50%) and Ga/N ratio (0.78 versus 1.25). In this paper, the effects of epilayer doping, dc bias, nitrogen flow rate and photo-irradiation flux on GaN etch rates, surface morphology and composition are presented. Finally, preliminary results on the use of a KrF excimer laser beam in the GaN photo-assisted RIE process are presented.
- Research Organization:
- Univ. of Houston, TX (US)
- Sponsoring Organization:
- National Aeronautics and Space Administration; National Science Foundation (NSF)
- OSTI ID:
- 20104757
- Resource Relation:
- Conference: 1999 Materials Research Society Spring Meeting, San Francisco, CA (US), 04/05/1999--04/08/1999; Other Information: PBD: 1999; Related Information: In: Wide-band semiconductors for high-power, high-frequency and high-temperature applications -- 1999. Materials Research Society symposium proceedings: Volume 572, by Binari, S.C.; Burk, A.A.; Melloch, M.R.; Nguyen, C. [eds.], 575 pages.
- Country of Publication:
- United States
- Language:
- English
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