Volatile organic compounds (VOCs) gas sensor deposited with amorphous ZnSnO 3 thin film on new MEMS structure

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 (RF) magnetron sputtering. Amorphous structures were then formed through rapid thermal annealing (RTA) at [Formula: see text]C. The process consumed only approximately 24.4[Formula: see text]mW at an operating temperature of [Formula: see text]C 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 X-ray diffractometer (XRD) and high-resolution transmission electron microscopy (HRTEM), effectively reducing charge transport impedance and improving electron mobility. X-ray photoelectron spectroscopy (XPS) analysis showed that the annealing process helped increase the lattice oxygen content, further optimizing sensing performance. Gas sensing experiments showed that at a volatile organic compounds (VOCs) concentration of 5 ppm, the sensor achieved a response rate of 41.1%, demonstrating high selectivity for VOCs, a 4[Formula: see text]s response time, and a 7[Formula: see text]s recovery time, exhibiting high sensitivity and fast response characteristics. Furthermore, the response remained consistent across multiple cycles, indicating excellent stability of the sensor.