多层薄膜热应力模拟

针对MEMS器件和光电器件的薄膜结构在高温下产生的应力与应变会严重影响器件结构与功能的问题,本文采用Suhir异质生长薄膜热应力计算理论分析了三层薄膜结构的热应力大小分布情况,得到了不同镀膜温度、膜厚、基底厚度等条件下的热应力变化趋势,解决了困扰有限元分析的奇异点问题。通过分析模型与有限元分析结果的比对,得到该计算模型的应力分布较为符合有限元分析的结果,最大剪切应力差距约为6.1%。列举了一个通过分析关系对材料进行优化的实例。这些研究结果对恶劣工作环境下的MEMS器件以及光电子器件的薄膜设计具有一定的借鉴意义。

Calculation and simulation of thermal stress of multilayer films

The stress and strain generated by the film structures of MEMS devices and optoelectronic(OE)devices at high temperatures will seriously affect the structures and function of the devices.In this paper,the thermal stress of the three-layer film structure is analyzed by the thermal stress calculation theory of the Suhir heterogeneous growth film.According to the distribution,the thermal stress changes under different coating temperatures,film thicknesses and substrate thicknesses are obtained,which solves the problem of finite element analysis-singular point problem,and finally compares the analytical model with the finite element analysis results.The analysis shows that the stress distribution of the calculated model is in line with the analysis results of the finite element analysis,and the maximum shear stress difference is about 30%.Finally,an example of optimizing materials through analytical relationships is listed.These findings have certain reference significance for MEMS devices and film design of optoelectronic devices in harsh working environments.