SiC MOSFET功率循环退化机制及多机理耦合寿命模型研究

SiC MOSFET既继承了传统Si 功率器件高开关速度、低损耗的优点，又具有SiC材料所特有的高耐压、低导通电阻、极端环境适用性等优势，成为近年来功率器件发展的焦点。目前，功率循环试验是评估SiC MOSFET器件实际使用寿命和退化机制的最有效的方法之一，本项目针对SiC MOSFET器件寿命评估的关键技术难点，基于功率循环试验明确SiC MOSFET器件宏观电学和热学参数退化的微观物理机制，提取退化规律，突破考虑多失效机理耦合的寿命建模关键技术，基于多元Copula函数表征多失效机理之间的关联关系，基于贝叶斯方法解决模型参数的估计问题，构建热机械累积损伤、栅氧化层累积损伤，体二极管退化累积损伤三种主要失效物理机制的耦合寿命模型，支撑我国SiC MOSFET器件的研制、生产和应用。

SiC MOSFET not only inherits the advantages of high switching speed and low loss of traditional Si power device, but also has the unique advantages of high breakdown voltage, low conduction resistance, and extreme environmental applicability. It has become the focus of power device in recent years. At present, the power cycling is one of the most effective methods to evaluate the actual lifetime and degradation mechanism of SiC MOSFET. This project aims at the key technical difficulties in the lifetime assessment of SiC MOSFET. Based on the power cycling test, the degradation micro-physical mechanism and the change law of macroscopic electrical and thermal parameters of SiC MOSFET will be studied, and the key technology of lifetime modeling considering the coupling of multiple failure mechanisms will be broken through. The relationship between multiple failure mechanisms will be characterized by multivariate Copula function. Based on Bayesian method, model parameters will be solved. The coupling model of the three main failure mechanisms combining thermal mechanical cumulative damage, gate oxide cumulative damage, body diode degradation cumulative damage will be established, which will support the development, production and application of SiC MOSFET in China.