Micromechanical GaAs Thermal Convertor for Gas Sensors

This paper discusses design, simulation and fabrication of new Micromechanical Thermal Converters (MTCs) based on GaAs developed for Gas sensors. GaAs MTCs seem to be very attractive for design of thermally based MEMS sensor devices. High thermal isolation of these devices can be done by implementing of free micromechanical hot plates which is designed as thin as possible. Metal oxide gas sensors generally work in high temperature mode that is required for chemical reactions to be performed between molecules of the specified gas and the surface of sensing material. There is a low power consumption required to obtain the operation temperatures in the range of 200 to 500 C. Mechanical stability and integrity and a fast thermal response are very important parameters that can not be neglected. These above mentioned design rules can be achieved using GaAs based micromachined concept of thermal converter.