A vertical-structured Ni/GaN Schottky barrier diode using electroplating nickel substrate
Journal
Japanese Journal of Applied Physics Part 2-Letters & Express Letters
Journal Volume
45
Journal Issue
20-23
Pages
L555-L558
Date Issued
2006
Author(s)
Wang, Shui-Jinn
Chen, Tron-Min
Uang, Kai-Ming
Chen, Shiue-Lung
Hsla, Tung-Sheng
Ku, Hon-Yi
Liou, Bor-Wen
Abstract
In this work, a vertical-structured Ni/u-GaN (2 μm)/n-GaN (1.5 μm) Schottky barrier diodes (SBDs) employing an electroplating nickel substrate and laser lift-off processes is proposed and experimental results are reported. A metal system comprising a Ti/Al/Ti/Au mutilayer structure was used to form ohmic contact to n-GaN. A specific contact resistance as low as 6.64 × 10 -5 Ω·cm2 has been obtained after sample thermal annealing in Ar ambient at 800°C for 30s. A KOH etching to the u-GaN epilayer after the removal of sapphire was conducted and effect of KOH etching time on the device performance of the fabricated Schottky diodes was also investigated. Vertical-structured GaN SBDs with die size of 400 × 400 μm2 and Schottky contact area of 200 μm in diameter have been successfully fabricated. The extracted values of Schottky barrier height (φB), series resistance (Rs), and ideality factor (η) of the 60-s-KOH etched SBDs were 0.78 eV, 1.9mΩ, and 1.06, respectively. © 2006 The Japan Society of Applied Physics.
Type
journal article