A Path Dependence Identification Method for Power MOSFETs Degradation Due to Bias Temperature Instability

Bias temperature instability represents a significant reliability concern for MOSFETs, leading to the degeneration of critical operational parameters. Effective identification of path dependence is a prerequisite to ensure that cumulative degradation under the mission profile can be accurately quantified, which involves determining whether the stress interactions affect the degradation. Despite its importance, path dependence is often overlooked, potentially compromising the reliability prediction. This paper presents a method for identifying the path dependence that may be inherent to the degradation process, including accelerated degradation test design and path dependence analysis. The practicality and effectiveness of the proposed method are demonstrated through experiments on Silicon MOSFETs, revealing its ability to identify path dependence and provide quantitative evaluation. Empirical results indicate that identical degradation parameters may not necessarily equate to a uniform physical condition of the material. Therefore, it is imperative to exercise increased caution when utilizing traditional models for cumulative degradation computations. © 2024 IEEE.