Design of a silicon microsensor array device for gas analysis

This paper describes the design of a silicon-based microsensor array for application in gas or odour monitoring. Individual sensor cells consist of both lateral and vertical electrode pairs to measure film conductance and/or capacitance. The fabrication process involves standard silicon technologies to integrate a platinum or nickel-iron heater below the sensor cells. A simulation of the device gives a thermal response time of only 60 ms and an ultra low power loss of about 50 mW at 400 degrees C per sensor. This compares well with experimental values observed on a similar device. The process technology is suitable for both the deposition of organic materials (e.g. conducting polymers) and inorganic materials (e.g. semiconducting oxides). A scheme of the transducer interface circuitry is also provided, and could be used in a portable battery-powered instrument. (C) 1996 Elsevier Science Ltd