The basic objective of this work was to investigate a suitable ohmic metallization to 3C-SiC epitaxial layer with relatively low process temperature, which is important for on-chip circuit integration. In this study, the ohmic contacts are associated with the catalytic-metal/SiC Schottky diode gas sensors operable at 400 degreesC. Therefore, the contacts must be reliable for efficient operation of the sensors at this temperature in air ambient. Several metallization schemes were studied and the observed electrical characteristics were correlated to the interface properties by secondary ion mass spectrometry. Nickel contacts to moderately doped (similar to10(17) cm(-3)) 3C-SiC epilayer did not exhibit linear current-voltage relationship even after annealing at 600 degreesC. On the other hand, aluminum exhibited considerably low intercontact resistance in the as-deposited condition. But with increase in annealing temperature the current flow between a couple of Al contacts was impeded presumably due to very high affinity of this metal for oxygen. Titanium exhibited good ohmic properties after annealing at 400 degreesC. However, higher temperature (600 degreesC) annealing in air ambient (intended to examine its stability limit) caused surface oxidation of the Ti layer. This problem was minimized by deposition of 100 nm An overlayer (on top of 400 nm Ti) which would increase the surface conductivity of the ohmic contacts and ensure stable wire bonding. (C) 2003 Elsevier Ltd. All rights reserved.