Microstructural stability of ohmic contacts to In{sub {ital x}}Ga{sub 1{minus}{ital x}}N
- University of Florida, Gainesville, Florida 32611 (United States)
- AT&T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)
The microstructural properties and interdiffusion reactions of some common metallization schemes (Au/Ge/Ni, Ti/Pt/Au, WSi{sub {ital x}}, and AuBe) on GaN and In{sub 0.5}Ga{sub 0.5}N have been examined using scanning electron microscopy and Auger electron spectroscopy. The objective of this study was to investigate thermally stable and uniform contacts to both materials. The WSi{sub {ital x}} contacts were found to possess excellent thermal stability and retained good structural properties at annealing temperatures as high as 800{degree}C on GaN. These contacts on In{sub 0.5}Ga{sub 0.5}N had a minimum specific contact resistivity of 1.48{times}10{sup {minus}5} {Omega}cm{sup 2} and an excellent surface morphology following annealing at 700{degree}C. The increase in contact resistance observed at higher temperatures was attributed to intermixing of metal and semiconductor. By contrast the Ti/Pt/Au and Au/Ge/Ni contacts showed lower stabilities, but also showed little Au penetration into the underlying GaN. AuBe contacts had the poorest thermal stability of all four schemes investigated, with substantial reaction with GaN occurring even at 400{degree}C. The WSi{sub {ital x}} contact appears to be an excellent choice for application in high temperature GaN electronics. {copyright} {ital 1996 American Vacuum Society}
- OSTI ID:
- 288912
- Journal Information:
- Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena, Vol. 14, Issue 4; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
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