GaAs based micromachined thermal converter for gas sensors

The micromachining technology and an electro-thermo-mechanical performance analysis of GaAs based micromachined thermal converter (MTC) device to be designed for metal oxide gas sensors are presented. MTC device introduced exhibits a low power consumption due to by high thermal resistance values (Rth = 15–21 K/mW), uniform temperature distribution, a fast temperature time response (τ ∼ 1.5–1.8 ms), and good mechanical integrity and thermal stability. It is also fully compatible with the GaAs HEMT based signal-processing and controlling electronics to be monolithically integrated with the gas sensors. The both a simple analytical and three-dimensional thermal modeling of the MTC device was performed. It supported the high electro-thermal conversion efficiency and fast temperature time response of the MEMS device as evaluated by the experiments.