title: Ohmic contacts to N-face p-GaN using Ni/Au for the fabrication of polarization inverted light-emitting diodes.
abstract: The electrical properties of Ni-based ohmic contacts to N-face p-type GaN were investigated. The specific contact resistance of N-face p-GaN exhibits a linear decrease from 1.01 omega cm2 to 9.05 x 10(-3) omega cm2 for the as-deposited and the annealed Ni/Au contacts, respectively, with increasing annealing temperature. However, the specific contact resistance could be decreased down to 1.03 x 10(-4) omega cm2 by means of surface treatment using an alcohol-based (NH4)2S solution. The depth profile data measured from the intensity of O1s peak in the X-ray photoemission spectra showed that the alcohol-based (NH4)2S treatment was effective in removing the surface oxide layer of GaN.
authors.affiliation: Department of Materials Science and Metallurgical Engineering, Sunchon National University, Sunchon, Jeonnam 540-742, Korea.
authors.forename: Seung Cheol
authors.initials: SC
authors.lastname: Han
authors.forename: Jae-Kwan
authors.initials: JK
authors.lastname: Kim
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Dong Min
authors.initials: DM
authors.lastname: Lee
authors.forename: Jae-Sik
authors.initials: JS
authors.lastname: Yoon
authors.forename: Jong-Kyu
authors.initials: JK
authors.lastname: Kim
authors.forename: E F
authors.initials: EF
authors.lastname: Schubert
authors.forename: Ji-Myon
authors.initials: JM
authors.lastname: Lee