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Title: Ohmic contacts and Schottky barriers to n-GaN

Journal Article · · Journal of Electronic Materials
; ; ; ; ; ;  [1]; ;  [2]
  1. Univ. of Illinois at Urbana-Champaign, IL (United States)
  2. Univ. of California, Berkeley, CA (United States)

Gallium nitride is a highly promising wide bandgap semiconductor with applications in high power electronic devices and optoelectronic devices. For these devices to be realized, metallization, both ohmic and rectifying must be available. In this manuscript, we discuss the properties of ohmic contacts and Schottky barriers on n-type GaN. The most recent ohmic metallization scheme involves Ti/Al based composites, namely Ti/Al/Ni/Au (150 A/2200 A/400 A/500 A) preceded by a reactive ion etching (RIE) process which most likely renders the surface highly n-type. With annealing at 900{degree}C for 30 s, contact with specific resistivity values less than {Rho}{sub 8} = 1x10{sup -7} {Omega} cm{sup 2} for a doping level of 4x10{sup 17} cm{sup -3} were obtained. Schottky barriers with Ti, Cr, Pd, Au, Ni, and Pt have been reported; however, we will concentrate here on Pt based structures as they yield a large barrier height of 1.1 eV. Both capacitance-voltage and current-voltage analyses have been carried out as a function of temperature to gain insight into the current conduction processes involved. Attention must now be turned to the modification needed to render these contacts reliable. 30 refs., 8 figs.

Sponsoring Organization:
USDOE
OSTI ID:
420698
Report Number(s):
CONF-960202-; ISSN 0361-5235; TRN: 97:000616-023
Journal Information:
Journal of Electronic Materials, Vol. 25, Issue 11; Conference: Annual meeting and exhibition of the Minerals, Metals and Materials Society (TMS), Anaheim, CA (United States), 4-8 Feb 1996; Other Information: PBD: Nov 1996
Country of Publication:
United States
Language:
English