全息光栅金属掩模的制备与应用探究

Preparation and Application of Holographic Grating Metal Mask

摘要: 全息光栅是一种广泛应用于光谱仪器的分光器件，也是光谱仪器的核心器件，光栅的种类很多，本文优化了基于金属掩模的全息微型纳米光栅的制作方案。基于GaAs衬底，用全息光刻和电感耦合等离子体(ICP)干燥蚀刻的方法制备了300 nm周期光栅。在实验中，将磁控溅射培养的金属硬罩引入蚀刻过程中，作为光栅蚀刻的屏障层，制备了Ni掩模以提高掩模的质量。比较了光刻胶、SiO2和Ni作为干燥蚀刻掩模对光栅蚀刻深度和形貌的影响。实验结果表明，该膜具有较强的抗蚀性。SEM的结果显示，100纳米厚的Ni作为硬掩模可以达到良好的光栅结构，深度宽度比约4.9，槽宽100纳米，蚀刻深490纳米，具有陡峭的侧壁形态，周期性好，均匀性好，对减小芯片等图形复制过程中深度或精度不足情况有借鉴意义。

Abstract: Holographic grating is a kind of spectroscopic device widely used in spectroscopic instruments, and it is also the core device of spectroscopic instruments. There are many types of gratings. In this paper, the fabrication scheme of holographic micro-nano gratings based on metal masks is optimized. Based on GaAs substrate, a 300 nm periodic grating was prepared by holographic lithography and inductively coupled plasma (ICP) dry etching. In the experiment, a metal hard cover cultured by magnetron sputtering was introduced into the etching process as a barrier layer for grating etching, and a Ni mask was prepared to improve the quality of the mask. The effects of photoresist, SiO2 and Ni as dry etching masks on the depth and morphology of gratings were compared. The experimental results show that the film has strong corrosion resistance. The SEM results show that 100 nm thick Ni can achieve a good grating structure as a hard mask. The depth-to-width ratio is about 4.9, the groove width is 100 nm, and the etching depth is 490 nm. Well, it is of significance to reduce the lack of depth or accuracy in the process of copying graphics such as chips.