DESIGN OF A CMOS HEATER SUPPORT FOR THIN FILM GAS SENSORS

摘要

In this work, the design of an integrated heater support for thin film gas sensor is presented. The support, based on a micromachined bulk silicon, is carried out with a poly-p heater fully immersed in the silicon oxide and provided with 4 interdigital structures where the sensing thin film materials is deposited. With this structure formed by 4 sensor and a heater is possible to build a base module for a multi-sensing device and/or use its also as support for sensing material characterisation. This module present a digital standard voltage supply (5V), a low value of thermal time-constant (about 5 ms). an uniform temperature on all active sensing area, a low power dissipation for each sensor (< 15 mW in continuos regime at 280 °C) and a small dimension (1.2×1.2 mm2 for the heater global area and 4.2×4.2 mm2 for the entire chip).