基于POF的温度应力加速试验失效机理一致性研究

摘要

目的 通过失效物理手段得到温度加速寿命试验的失效机理突变点,节省试验样本,并为加速寿命试验的有效性提供保障.方法 利用电子产品典型失效物理模型,在求解MOSFET器件激活能的基础上确定失效机理突变点,并开展失效物理分析,从微观分析的角度验证失效机理一致性判定方法 的理论正确性和工程适用性.结果 MOSFET器件在温度低于240℃时,失效机理没有发生改变;温度高于240℃时,失效机理发生了改变,与前述失效机理不一致.结论 基于失效物理的方法 可以确定器件机理发生变化的温度应力点,所需样本量小.%Objective To save test sample and provide guarantee for efficiency of accelerated test by obtaining change point of failure mechanism in the POF-based accelerated life test.Methods Typical physical model of failure was applied to deter-mine the change point of failure mechanism based on calculating the activation energy of MOSFET. And failure physical analy-sis was implemented to verify the theoretical correctness and engineering applicability of judgment method on consistency of failure mechanism from the micro perspective.Results When temperature was below 240℃ , the failure mechanism did not change. And when the temperature was higher than 240℃ , the failure mechanism changed. It was inconsistent with the above mentioned failure mechanism.Conclusion The POF method can confirm the temperature stress point of changed device me-chanism and the required sample size is small.