This study successfully deposited ZnSnO 3 thin films on microelectromechanical systems (MEMS) structures using a co-sputtering technique combining high-power pulsed magnetron sputtering (HiPIMS) and radio-frequency magnetron sputtering (RF). Amorphous structures were then formed through rapid thermal annealing (RTA) at 500℃. The process consumed only approximately 24.4 mW at an operating temperature of 300℃ and exhibited stable and uniform thermal control. The sensing film was integrated within the MEMS structure, demonstrating high process compatibility. Structural analysis confirmed the amorphous properties of the film using XRD and HRTEM, effectively reducing charge transport impedance and improving electron mobility. XPS analysis showed that the annealing process helped increase the lattice oxygen content, further optimizing sensing performance. Gas sensing experiments showed that at a VOCs concentration of 5 ppm, the sensor achieved a response rate of 41.1%, demonstrating high selectivity for VOCs, a 4-second response time, and a 7-second recovery time, exhibiting high sensitivity and fast response characteristics. Furthermore, the response remained consistent across multiple cycles, indicating excellent stability of the sensor.
Chou et al. (Tue,) studied this question.