[19p-PB3-1~24] 13.7 Compound and power electron devices and process technology

[19p-PB3-22] Contact resistance reduction of Au/Ni electrode to p-type GaN by heat treatment

〇(M2)Sou Kuroyanagi¹, Takaaki Kondo¹, Satoshi Yasuno², Tomoyuki Koganezawa², Naotaka Iwata¹ (1.Toyota Technological Inst., 2.Japan Synchrotron Radiation Research Inst.)

Keywords:p-type GaN, Au/Ni, contact resistance

We investigated the contact resistances as well as the conditions for surface and interface of Au(10nm)/Ni(10nm)/p-type GaN(200nm) samples by heat treatments. The heat treatments were performed at temperatures ranging from 520 to 670℃ for 2.5 minutes in N₂ ambient. The circular transmission line model was employed for characterization of the specific contact resistance. In order to characterize the metal-semiconductor interface, the hard X-ray photoemission spectroscopy at beam line BL46XU of SPring-8 was employed. The contact resistances were found to be decreased with increasing the heat treatment temperature, and the surface became rough after the treatment at 640℃ or more. As for the sample heat-treated at 610℃, the specific contact resistance obtained was 3Ω・cm² with smooth surface, and formation of Ni oxide was recognized at the interface.