Fabrication at wafer level of micromachined gas sensors based on Sno 2 nanorods deposited by PECVD and gas sensing characteristics

Sn02 nanorods were successfully deposited on 3" Si/Si02 wafers by inductively coupled plasma-enhanced chemical vapor deposition (PECVD) and a wafer-level patterning of nanorods layer for miniaturized solid state gas sensor fabrication were performed. Uniform needle-shape Sn02 nanorods in situ grown were obtained under catalyst- and high temperature treatment-free growth condition. These nanorods have an average diameter between 5 and IS nm and a length of 160 to 300 nm. The Sn02-nanords based gas sensors were tested towards NH3 and CH30H and gas sensing tests show remarkable response, showing promising and repeatable results compared with the Sn02 thin films gas sensors.