Silicon bridge type micro-gas sensor array

Silicon bridge type micro-gas sensor array was fabricated for detecting hydrogen sulfide (H2S) and ethanol (C2H5OH) gases simultaneously. Anisotropic wet etching of silicon in 25 wt.% KOH solution at 80 °C and silicon reactive ion etching (RIE) were applied to achieve the bridge type sensor for low power consumption. The fabricated device size and active region are 2 mm× 2 mm and 85 μm× 75 μm, respectively. SnO2-CuO and SnO2-Pt thin films were deposited on bridge type micro-heater in a simple way. The sensing characteristics of the packaged micro-sensor to target gases were also investigated.