Please use this identifier to cite or link to this item:
Title: Effects of plasma surface treatment on ohmic contact to n-GaN
Authors: Chor, E.F. 
Kang, X.J. 
Issue Date: 2001
Citation: Chor, E.F.,Kang, X.J. (2001). Effects of plasma surface treatment on ohmic contact to n-GaN. Materials Research Society Symposium Proceedings 680 : 184-189. ScholarBank@NUS Repository.
Abstract: We have investigated the effects of plasma surface treatment on ohmic contacts to n-type GaN. Prior to metal evaporation, n-GaN surface was etched either chemically using aqua-regia (control sample) or by means of inductively coupled Cl2/BCl3, N2 or Ar plasmas. The metal system adopted in our investigation was Ti/Al/Pd/Au. The as-deposited Ti/Al/Pd/Au contact on aqua-regia treated n-GaN exhibits an ohmic behavior with a specific contact resistance (ρc) of 2×10-4 Ωcm2. After annealing at 500°C for 5min, ρc is reduced by approximately 2 orders of magnitude to 5×10 -6Ωcm2. For Cl2/BCl3 and N2 plasma treated n-GaN surface, the as-deposited Ti/Al/Pd/Au contacts also yield ohmic behavior and ρc's are about 2×10-4 and 5×10-4Ω cm2 respectively. After annealing at 500°C for 5min, ρc's are reduced by about 3 orders of magnitude to around 5×10-7 and 8×10-7Ω cm2 respectively. On the other hand, the as-deposited Ti/Al/Pd/Au contact on Ar plasma treated n-GaN exhibits a non-ohmic behavior. After annealing at 500°C for 5min, ρc is about 5×-10-7 cm2 and the lowest ρc of 7×10-8Ω cm2 is obtained after annealing at 700°C for 5min. The contacts on other surface treated n-GaN are found to degrade at 700°C annealing. By comparing the values of ρc for various surface treatments, particularly those after annealing, it is observed that plasma etching can be used beneficially in the formation of ohmic contacts - plasma surface treatment using Cl2/BCl3, N2 or Ar has resulted in an order of magnitude reduction in ρc compared to chemical surface treatment by aqua-regia. © 2001 Materials Research Society.
Source Title: Materials Research Society Symposium Proceedings
ISBN: 1558996168
ISSN: 02729172
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

Page view(s)

checked on Jun 7, 2020

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.