Sensing behavior and mechanism of titanium dioxide-based MOS hydrogen sensor

✍ Scribed by Lallan Yadav; Naveen Chandra Gupta; R. Dwivedi; Ravi S. Singh

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 353 KB
• Volume: 38
• Category: Article
• ISSN: 0026-2692
• DOI: 10.1016/j.mejo.2007.09.020

✦ Synopsis

A Pd/TiO 2 /Si MOS sensor (Pdtisin sensor) is proposed for the detection of hydrogen gas. The sensor is fabricated on a p-type /1 1 1S silicon wafer having resistivity of 3-6 O cm. The thickness of TiO 2 in this structure is about 600 nm. The capacitance-voltage (C-V) and conductance-voltage (G-V) characteristics of the device is observed on the exposure of hydrogen gas at room temperature. The mechanism of hydrogen sensing of titanium dioxide-based MOS sensor (MOS capacitor) has been investigated by evaluating the change in flat-band voltage (V FB ) and fixed surface state density of the device in presence of hydrogen gas. The device exhibits very large parallel shift in C-V as well in G-V characteristics. The possible mechanism on Pd/TiO 2 and TiO 2 /Si surface in presence of hydrogen gas has been proposed. The response and recovery time of the device is also measured at room temperature.