Reliability aspects of thermal micro-structures implemented on industrial 0.8 mu m CMOS chips

This paper discusses the reliability characterization of thermal micro-stru ctures implemented on industrial 0.8 mum CMOS chips. Various degradation an d failure mechanisms are identified and evaluated under high temperature op eration, At high temperatures the mechanisms are many and varied, and co-in cidental thermally-induced mechanical defects are found in both the poly-Si heater and the poly-Si temperature sensor, along with temperature- and cur rent-enhanced interlayer diffusion degradation of the heater contacts. Loca l reduction in the device thermal capacity by using silicon micro-machining can be expected to hold the promise of a number of significant advantages, especially for limiting current stressing of the contact regions. The resu lts can be used to optimize the design of thermally based micro-sensors on CMOS chips, such as CMOS compatible chemoresistive gas sensors. (C) 2001 El sevier Science Ltd. All rights reserved.