Unintentional hydrogenation of GaN and related alloys during processing
- University of Florida, Gainesville, Florida 32611 (United States)
- Hughes Research Laboratories, Malibu, California 90265 (United States)
- Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
- AT&T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)
- U.S. Army Research Office, Research Triangle Park, North Carolina 27709 (United States)
Atomic hydrogen plays an important role in GaN, passivating the electrical activity of Mg acceptors during cooldown after metal organic chemical vapor deposition growth, and thereby preventing achievement of high {ital p}-type doping levels unless an annealing step is performed. We have found that hydrogen is easily incorporated into GaN and related materials during many different process steps, including boiling in water, wet chemical etching in KOH-based solutions, dielectric deposition using SiH{sub 4} or dry etching in Cl{sub 2}/CH{sub 4}/H{sub 2}Ar electron cyclotron resonance plasmas. In each of these cases we have employed deuterated chemicals and detected the incorporation of deuterium into GaN using high sensitivity secondary ion mass spectroscopy measurements. Hydrogen is found to have a diffusivity of {approx_gt}10{sup {minus}11} cm{sup 2}s{sup {minus}1} at 170{degree}C, and to passivate the electrical activity of Mg and C acceptors and also the native shallow donors in InGaN and InAlN. Annealing at 450{endash}500{degree}C restores the electrical activity, but the hydrogen does not physically leave the films until much higher ({approximately}800{degree}C) temperatures. The activation energies for dopant reactivation are of the order of 2.5 eV in bulk samples, where hydrogen retrapping is expected to be significant. {copyright} {ital 1996 American Vacuum Society}
- Research Organization:
- Sandia National Laboratory
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 285390
- Report Number(s):
- CONF-9510385--
- Journal Information:
- Journal of Vacuum Science and Technology, A, Journal Name: Journal of Vacuum Science and Technology, A Journal Issue: 3 Vol. 14; ISSN 0734-2101; ISSN JVTAD6
- Country of Publication:
- United States
- Language:
- English
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