优化设计了基于金属掩模的全息光刻微纳光栅制备工艺方案,基于GaAs衬底利用全息光刻和感应耦合等离子体(ICP)干法刻蚀技术制备出周期为860 nm的光栅图形。将磁控溅射生长的金属硬掩模作为光栅刻蚀的阻挡层引入到刻蚀工艺中,并利用lift-off技术制备Ni掩模。对比了以光刻胶、SiO2、Ni三种材料作为ICP干法刻蚀掩模对光栅刻蚀深度及形貌的影响,结果表明,Ni掩模具有较强的抗刻蚀特性。扫描电镜测试结果显示:将50 nm厚的Ni作为硬掩模,可以实现深宽比约为4.9的光栅结构,该结构的槽宽为300 nm,刻蚀深度为1454 nm,具有陡直的侧壁形貌及良好的周期性和均匀性。

The fabrication process of holographic lithography micro-nano gratings using metal masks is designed and optimized. First, an 860 nm periodic grating is prepared using holographic lithography and inductively coupled plasma (ICP) dry etching on the GaAs substrate. The hard metal mask grown by magnetron sputtering is introduced into the etching process as a barrier layer for grating etching and the Ni mask is fabricated by the lift-off method. It has been shown that when photoresist, SiO₂, and Ni are used as masks for ICP dry etching, they determine the etching depth and morphology of the grating. Results show that the Ni mask has strong etch resistance. Scanning electron microscopy demonstrates that Ni with a thickness of 50 nm can be used as a hard mask to create a grating with an aspect ratio of about 4.9. The grating has a groove width and etching depth of 300 nm and 1454 nm, respectively, with steep sidewall morphology and good periodicity and uniformity.