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

An integrated gas sensor array is promising to overcome the poor selectivity and drift encountered by individual gas sensor. Micromachined gas sensor array was fabricated using the post-process micro-machining technology of silicon integrated circuit (IC). The size of a 2 x 4 array is 2 mm x 4 mm, and 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 with about 9 mW applied power, and thermal response time constant of a micro-heater is about 10 ms. The techniques of oxygen radical assisted EB evaporation was utilized to prepare SnO2. sensitive films that show high sensitivity and good selectivity to C2H5OH. (C) 2001 Elsevier Science B.V. All rights reserved.