A Room-Temperature TiO 2 -based Ammonia Gas Sensor with Three-Dimensional Through-Silicon-Via Structure

Over the past few decades, ammonia (NH 3 ) is commonly used in the petrochemical and semiconductor industries. Exposed to NH 3 is dangerous to life and continuous monitoring of NH 3 becomes vital. Sensitive and stable ammonia gas sensors with low-power consumption have gained increasing attention. This study uses a through-silicon via (TSV) technology and atomic layer deposition (ALD) to fabricate a three-dimensional (3D) TSV-structured room temperature TiO 2 gas sensor. For various NH 3 concentrations, the sensor response for the 3D TiO 2 gas sensor increased if the NH 3 concentration is increased. In terms of the stability and the reproducibility of the 3D room temperature TiO 2 NH 3 gas sensor at 10 ppm NH 3 gas, the sensor response is about 9.35% on average, with an inaccuracy of <± 0.8%. For various gas measurements, the sensor also exhibits good selectivity for NH 3 gas. This gas sensor of good stability, reproducibility, and selectivity with low power consumption can be used in various applications.