Micro-machined gas sensor array based on metal film micro-heater

An integrated gas sensor array is promising to overcome the poor selectivit y and drift encountered by individual gas sensor. Micromachined gas sensor array was fabricated using the post-process micro-machining technology of s ilicon integrated circuit (IC). The size of a 2 x 4 array is 2 mm x 4 mm, a nd the active area of each cell is 50 [im x 50 tm. The electric properties, thermal characteristics. and the response to standard gases of the sensor array were investigated. The micro-heater can be driven to 400 degreesC wit h about 9 mW applied power, and thermal response time constant of a micro-h eater is about 10 ms. The techniques of oxygen radical assisted EB evaporat ion was utilized to prepare SnO2. sensitive films that show high sensitivit y and good selectivity to C2H5OH. (C) 2001 Elsevier Science B.V. All rights reserved.