Ohmic contacts and Schottky barriers to n-GaN
- Univ. of Illinois at Urbana-Champaign, IL (United States)
- 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--
- Journal Information:
- Journal of Electronic Materials, Journal Name: Journal of Electronic Materials Journal Issue: 11 Vol. 25; ISSN JECMA5; ISSN 0361-5235
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mechanism of Ti/Al/Ti/W Au-free ohmic contacts to AlGaN/GaN heterostructures via pre-ohmic recess etching and low temperature annealing
Characteristics of Ti/Pt/Au ohmic contacts on p-type GaN/Al{sub x}Ga{sub 1-x}N superlattices