Accelerated life testing for micro-machined chemical sensors

Reliability & quality assurance are a major concern in the semiconductor industry. However, when developing a new mass-production technology, like micro-machined silicon-based devices, these aspects became particularly critical. Indeed, silicon-based thin-film tin-dioxide gas-sensor reliability has not been deeply studied; most of the completed studies address thick-film devices made on alumina substrates [1 - 3]. New test- methods & equipment must be engineered to meet the ever-increasing expectations of the marketplace. This paper justifies the need for new accelerated tests for chemical sensors. A new method which allows 'stressing the entire device structure' has been implemented. Test results obtained using this new approach allow us to evaluate the sensor reliability in the range of the requirements of applications using gas sensors.