Ohmic contact formation to doped GaN
- North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering
- Arizona State Univ., Tempe, AZ (United States). Center for Solid State Science
Ohmic contact strategies for n- and p-type GaN have been investigated electrically, chemically, and microstructurally using transmission line measurements, high-resolution EELS and cross-sectional TEM, respectively. The contributions to contact performance from work function differences, carrier concentrations, annealing treatments, and interface metallurgy have been examined. The contact materials of Ti, TiN, Au, and Au/Mg were deposited via electron beam evaporation; Al was deposited via thermal evaporation. As-deposited Al and TiN contacts to highly doped n-GaN were ohmic, with room-temperature specific contact resistivities of 8.6 {times} 10{sup {minus}5} {Omega} {center_dot} cm{sup 2} and 2.5 {times} 10{sup {minus}5} {Omega} {center_dot} cm{sup 2} respectively. The Ti contacts developed low-resistivity ohmic behavior as a result of annealing; TiN contacts also improved with further heat treatment. For p-GaN, Au became ohmic with annealing, while Au/Mg contacts were ohmic in the as-deposited condition. The performance, structure, and composition of different contact schemes varied widely from system to system. An integrated analysis of the results of this study is presented below and coupled with a discussion of the most appropriate contact systems for both n- and p-type GaN.
- OSTI ID:
- 395044
- Report Number(s):
- CONF-951155--; ISBN 1-55899-298-7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microstructure, electrical properties, and thermal stability of Ti-based ohmic contacts to {ital n}-GaN
Microstructure, electrical properties, and thermal stability of Al ohmic contacts to {ital n}-GaN
Related Subjects
ALUMINIUM
ANNEALING
COMPOSITE MATERIALS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
EVAPORATION
EXPERIMENTAL DATA
FABRICATION
GALLIUM NITRIDES
GERMANIUM
GOLD
INTERFACES
MAGNESIUM
MICROSTRUCTURE
MOLECULAR BEAM EPITAXY
SILICON
SILICON CARBIDES
TITANIUM
TITANIUM NITRIDES
TRANSMISSION ELECTRON MICROSCOPY
VAPOR PHASE EPITAXY