AVS 45th International Symposium
    Electronic Materials and Processing Division Thursday Sessions
       Session EM-ThP

Paper EM-ThP10
W-Based Ohmic Contacts on p- and n-Type GaN

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Electronic Materials and Processing Poster Session
Presenter: X. Cao, University of Florida, Gainesville
Authors: X. Cao, University of Florida, Gainesville
F. Ren, University of Florida, Gainesville
S.J. Pearton, University of Florida, Gainesville
A. Zeitouny, Technion-Israel Institute of Technology
M. Eizenberg, Technion-Israel Institute of Technology
J.C. Zolper, Office of Naval Research
C.R. Abernathy, University of Florida, Gainesville
R.J. Shul, Sandia National Laboratories
J.R. Lothian, Bell Laboratories, Lucent Technologies
Correspondent: Click to Email
W and WSi ohmic contacts on both p- and n-type GaN have been annealed at temperatures from 300-1000@degree@C. There is minimal reaction (@<=@100@Ao@ broadening of the metal/GaN interface) even at 1000@degree@C. Specific contact resistances in the 10@super -5@ ohm cm@super 2@ range are obtained for WSi@sub x@ on Si-implanted GaN with a peak doping concentration of ~5x10@super 20@cm@super -3@, after annealing at ~750@degree@C. On p-GaN, leaky Schottky diode behavior is observed for W, WSi@sub x@ and Ni/Au contacts at room temperature, but true ohmic characteristics are obtained at 250-300@degree@C, where the specific contact resistances are typically in the 10@super -2@ ohm cm@super 2@ range. The best contacts for W and WSi@sub x@ are obtained after 700@degree@C annealing for periods of 30-120 secs. The formation of @BETA@-W@sub 2@N interfacial phases appear to be important in determining the contact quality.