화학공학소재연구정보센터
Journal of Vacuum Science & Technology B, Vol.16, No.6, 3105-3107, 1998
Ohmic contacts to p-type GaN using a Ni/Pt/Au metallization scheme
We report a new Ni/Pt/Au trilayer metallization scheme for the formation of ohmic contact to p-GaN. Metal thin films with a thickness of 20 nm for Ni, 30 nm for Pt, and 80 nm for Au were deposited on the p-GaN layer (N-a = 9.4 x 10(16) cm(-3)) by electron beam evaporation. The samples, annealed at 500 degrees C for 30 s in a rapid thermal anneal system, showed a high quality ohmic contact with a low specific contact resistance of 2.1 x 10(-2) Omega cm(2). Auger electron spectroscopy analysis of the contact layers suggests that Pt plays an important role in the formation of ohmic contact, indicating that a Ni/Pt/Au trilayer can be used and that it is a promising material system for ohmic contact to p-GaN.