Typical n-type ohmic contact formation for GaN material systems requires high-temperature thermal processes. The high-temperature process often leads to a rough surface after the annealing step. Low-annealing-ohmic contact is advantageous to prevent undesired surface roughening on the metal stack during this thermal process. We report an approach to achieve low contact resistance on n-type GaN layers using a nitrogen plasma and a conventional Ti/Al-based metal stacks. We observed an as-deposit ohmic contact behavior on the n-type contact with a specific contact resistance (rc,sp) in the mid-E-6 Ω∙cm2 range. The rc,sp was further reduced to 6.8E-7 Ω∙cm2 after an annealing step at 600 oC.
A Study of Low-Annealing-Temperature Ohmic Contact on n-Type GaN LayersShyh-Chiang Shen, Georgia Institute of TechnologyMinkyu Cho, Georgia TechMarzieh Bakhtiary Noodeh, Georgia TechTheeradetch Detchprohm, Georgia TechRussell Dupuis, Georgia TechBarry Wu, Keysight Technologies, Inc.Don D’Avanzo, Keysight Technologies, Inc.Download Paper
10a.3 Vanadium-based Ohmic Contact on n-type AlGaN LayersTsung-Ting Kao, Georgia Institute of Technology,Xiao-Jia Jia, Georgia Institute of TechnologyYuh-Shiuan Liu, Georgia Institute of TechnologyTheeradetch Detchprohm, Georgia TechRussell Dupuis, Georgia TechShyh-Chiang Shen, Georgia Institute of Technology