硅基底多层薄膜结构材料残余应力的微拉曼测试与分析

Residual Stress Measurement and Analysis in Multilayer Film Si-Substrate Structure by Micro-Raman Spectroscopy Technique

针对MEMS器件制备中两种典型的硅基底多层薄膜结构的残余应力问题,本文提出了利用微拉曼光谱技术测量其残余应力的方法,分析并给出了硅基底多层薄膜结构中的残余应力分布规律。实验结果表明,在硅基底和薄膜内存在较大的工艺残余应力,残余应力在基底内靠近薄膜两侧部分呈非线性变化,在基底内主要呈线性变化,并引起基底整体翘曲。基于实验结果分析,提出了硅基底多层薄膜结构的分层结构模型。本文工作表明微拉曼光谱技术是测量与研究硅基底多层薄膜结构残余应力的一种有力手段。

Abstract： Aiming at residual stress in two typical multilayer film Si-substrate structures, micro- Raman spectroscopy technique is proposed in this paper to measure the residual stress and analyse its distribution in multilayer film Si-substrate structure. Experimental results show that significant residual stress formed in processing exists in both Si-substrate and film. In Si-substrate, nonlinearvariation of residual stress appears at both sides near the film, whereas there is a linear variation of residual stress in the internal region, which leads to a significantly overall warp of substrate. Based on experimental analysis, a stratification structure model for multilayer film Si-substrate structure is proposed. All above results show that micro-Raman spectroscopy technique is a powerful method to investigate the residual stress of multilayer film Si-substrate structure.