Ohmic contacts to Si-implanted and un-implanted n-type GaN
- Univ. of New Mexico, Albuquerque, NM (United States). Center for High Technology Materials
- Sandia National Labs., Albuquerque, NM (United States)
The authors report on ohmic contacts to Si-implanted and un-implanted n-type GaN on sapphire. A ring shaped contact design avoids the need to isolate the contact structures by additional implantation or etching. Metal layers of Al and Ti/Al were investigated. On un-implanted GaN, post metallization annealing was performed in an RTA for 30 seconds in N{sub 2} at temperatures of 700, 800, and 900 C. A minimum specific contact resistance (r{sub c}) of 1.4 {times} 10{sup {minus}5} {Omega}-cm{sup 2} was measured for Ti/Al at an annealing temperature of 800 C. Although these values are reasonably low, variations of 95% in specific contact resistance were measured within a 500 {micro}m distance on the wafer. These results are most likely caused by the presence of compensating hydrogen. Specific contact resistance variation was reduced from 95% to 10% by annealing at 900 C prior to metallization. On Si-implanted GaN, un-annealed ohmic contacts were formed with Ti/Al metallization. The implant activation anneal of 1,120 C generates nitrogen vacancies that leave the surface heavily n-type, which makes un-annealed ohmic contacts with low contact resistivity possible.
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 395043
- Report Number(s):
- CONF-951155-; ISBN 1-55899-298-7; TRN: IM9648%%120
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 27 Nov - 1 Dec 1995; Other Information: PBD: 1996; Related Information: Is Part Of Gallium nitride and related materials; Ponce, F.A. [ed.] [Xerox Palo Alto Research Center, CA (United States)]; Dupuis, R.D. [ed.] [Univ. of Texas, Austin, TX (United States)]; Nakamura, S. [ed.] [Nichia Chemical Industries, Tokushima (Japan)]; Edmond, J.A. [ed.] [Cree Research, Inc., Durham, NC (United States)]; PB: 993 p.; Materials Research Society symposium proceedings, Volume 395
- Country of Publication:
- United States
- Language:
- English
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