W and WSi{sub x} Ohmic contacts on {ital p}- and {ital n}-type GaN
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)
- Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)
- Department of Materials Engineering, Technion--Israel Institute of Technology, Haifa 32000 (Israel)
- Office of Naval Research, Arlington, Virginia 22217 (United States)
- Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
- Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States)
W and WSi Ohmic contacts on both {ital p}- and {ital n}-type GaN have been annealed at temperatures from 300 to 1000&hthinsp;{degree}C. There is minimal reaction ({le}100 {Angstrom} broadening of the metal/GaN interface) even at 1000&hthinsp;{degree}C. Specific contact resistances in the 10{sup {minus}5}&hthinsp;{Omega}&hthinsp;cm{sup 2} range are obtained for WSi{sub x} on Si-implanted GaN with a peak doping concentration of {approximately}5{times}10{sup 20}&hthinsp;cm{sup {minus}3}, after annealing at 950&hthinsp;{degree}C. On {ital p}-GaN, leaky Schottky diode behavior is observed for W, WSi{sub x} and Ni/Au contacts at room temperature, but true Ohmic characteristics are obtained at 250{endash}300&hthinsp;{degree}C, where the specific contact resistances are, typically, in the 10{sup {minus}2}&hthinsp;{Omega}&hthinsp;cm{sup 2} range. The best contacts for W and WSi{sub x} are obtained after 700&hthinsp;{degree}C annealing for periods of 30{endash}120 s. The formation of {beta}-W{sub 2}N interfacial phases appear to be important in determining the contact quality. {copyright} {ital 1999 American Vacuum Society.}
- OSTI ID:
- 359783
- Report Number(s):
- CONF-981126--
- Journal Information:
- Journal of Vacuum Science and Technology, A, Journal Name: Journal of Vacuum Science and Technology, A Journal Issue: 4 Vol. 17; ISSN 0734-2101; ISSN JVTAD6
- Country of Publication:
- United States
- Language:
- English
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