Fabrication and characterization of pulse laser deposited Ni2Si Ohmic contacts on n-SiC for high power and high temperature device applications

Ni2Si Ohmic contacts were fabricated via pulsed laser deposition on n-SiC. The contacts electrical, structural, compositional, and surface morphologic al properties were investigated as a function of annealing temperatures ran ging from 700 to 950 degreesC. The as-deposited and 700 degreesC annealed c ontacts were non-Ohmic. Annealing at 950 degreesC yielded excellent Ohmic b ehavior, an abrupt void free interface, and a smooth surface morphology. No residual carbon was present within the contact metallization or at the con tact-SiC interface and the contact showed no appreciable thickness increase as a result of the annealing process. Our results demonstrate that aside f rom maintaining the desirable electrical integrity associated with Ni and N i/Si Ohmic contacts, the Ni2Si Ohmic contacts possessed improved interfacia l, compositional, microstructural, and surface properties which are require d for reliable high temperature and high power device operation. (C) 2001 A merican Institute of Physics.