Low-resistance and high-reflectance Ni/Ag/Ru/Ni/Au ohmic contact on p-type GaN
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Kyungbuk 790-784 (Korea, Republic of)
We report a metallization scheme of low-resistance, high-reflectance, and thermally-stable ohmic contact on p-type GaN. The specific contact resistivity as low as 5.2x10{sup -5} {omega} cm{sup 2} and the high reflectance of 91% were simultaneously obtained from Ni (50 A )/Ag (1200 A)/Ru (500 A)/Ni (200 A)/Au (500 A) contact annealed at 500 deg. C in O{sub 2} ambient. The oxidation annealing promoted the outdiffusion of Ga atoms to dissolve in the Ag layer, leaving Ga vacancies below the contact. The Ru layer could act as a diffusion barrier for intermixing of the reflective Ag with upper layers of Ni and Au. Thus, suppression of the intermixing results in the high reflectance and good thermal stability of the contact.
- OSTI ID:
- 20634405
- Journal Information:
- Applied Physics Letters, Vol. 85, Issue 19; Other Information: DOI: 10.1063/1.1819981; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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