Defect Excitation and Failure Analysis of MEMS Gas Sensors Based on FTA and RET Methods

The reliability of microelectromechanical system (MEMS) gas sensors is critical for their deployment in industrial automation and environmental monitoring. However, failure mechanisms under harsh conditions remain poorly understood. This study combines Fault Tree Analysis (FTA) and Reliability Enhancement Testing (RET) to systematically investigate defect excitation in MEMS gas sensors. The FTA identifies gas-sensitive films and microheaters as weak links, while the RET reveals a 93.3% failure rate under controlled thermal and mechanical stresses. Microscopic analysis demonstrates that microcracks in the gas-sensitive film originate from mismatched thermal expansion coefficients between the film and electrodes, exacerbated by primary defects introduced during fabrication. These findings not only advance the understanding of failure mechanisms in MEMS devices but also propose design optimizations to enhance material compatibility and manufacturing processes. This work aligns with the growing demand for high-reliability MEMS sensors in applications such as biomedical diagnostics and hazardous environments monitoring, offering a roadmap for durable sensor development. [2025-0033]