Semiconductor gas sensor compatibility with CMOS technologies

This paper describes the development of a technological process that allows the integration of gas sensors and thin film CMOS circuitry. The main technological points for the integration of gas sensors in a standard CMOS process and the effects on the full process will be described. A set of preliminary tests have been done prior to the definition of a CMOS compatible process forý-structures and a complete test of sensitive materials are presented in order to determine the materials with most appropriate annealing temperatures for CMOS compatibility. Results show that gas sensors can be integrated with their circuitry, although require of special materials and non-CMOS standard processing as post-processing sequences.