机刻光栅复合基底对薄膜内应力的影响研究

Study on the Influence of the Gratings Composite Substrate on the Internal Stress of the Film

机械刻划制备大尺寸中阶梯衍射光栅是亚微米级的成槽挤压过程,在薄膜成槽变形过程中应力的产生与分布会直接影响槽形质量。受限于实际加工及检测手段,无法对薄膜内应力进行有效研究与计算。通过建立无基底纯铝膜模型、仅存玻璃基底铝薄膜模型与具有玻璃-铬复合基底的真实铝薄膜等三种模型,采用有限元模拟压痕试验分析方法,对比分析受压区域应力分布情况,总结受压薄膜内应力分布规律。实验研究表明",三明治"式复合基底有助于薄膜内竖直方向内部应力的分布优化。此研究创新了基底效应与薄膜内应力相互影响关系的研究方法,同时为机刻光栅制备工艺提供借鉴指导。

The mechanical ruling process of fabricating large size echelle is a sub-micro groove extrusion process. The generation and distribution of the stress in the ruling film process will directly affect the groove quality. Due to the actual processing and testing methods,the internal stress of thin film cannot be effectively studied and calculated. In this paper,we compared different regional compressive stress distribution and summarized the distribution regularities by adopting the finite element simulation of indentation test and establishing the true aluminum film model with glass-chromium composite substrate,only glass substrate model and only pure aluminum film model. Experimental results have shown that the sandwich type composite substrate film is helpful to optimize internal stress distribution of film along the vertical direction. This research has innovated the research method of the interaction between substrate effect and the internal stress of thin film,and provided guidance for the ruling process of grating.