CMOS compatible gas sensor arrays for hostile environments

This study demonstrates the first SiC-based gas sensor array, which is compatible with CMOS processing and capable of discriminating between the constituents of mixed gas species under harsh environments. The oxides, HfO₂ and TiO₂, have been formed using identical processing conditions, enabling the realization of an array, which can be monolithically integrated with amplifier circuitry. Furthermore, a comparison is made between catalytic gate contacts of Pt and Pd. Exposure of the SiC-based (MIS configuration) gas sensors to environments containing mixtures of H₂ and O₂, reveals that the gas sensitivity depends on both the dielectric and contact materials. It is this observed difference in response that facilitates the creation of a resilient sensor arrays, which can operate at 300°C.