面向高精度、低损伤闪耀光栅的摩擦诱导纳米加工机理研究

Due its high diffraction efficiency, the blazed grating can greatly improve the sensitivity, resolution and measurement range for the grating measurement system, and hence becomes the core functional component to promote precision manufacturing. The research and development of high-precision grating was highlighted in the “Made in China 2025” plan. However, traditional methods for fabricating blazed grating still have disadvantages and need to be improved. For example, mechanical scratching can result in surface roughness, and the grating profile is difficult to be controlled by the holographic ion beam etching technique. Therefore, innovative processing methods are urgently needed for producing high-quality blazed gratings. Since friction-induced method has advantages in realizing inclined planes, a new method based on friction-induced nanofabrication will be proposed for producing high-precision and low-damage blazed gratings. In this project, the key experimental parameters affecting the formation and selective etching of the mechanical scratching-induced deformed layer will be firstly investigated, and the corresponding mechanisms for the formation and selective etching of the deformed layer will be studied. Then the effective control of the friction-induced selective etching process will be achieved, and the relationship between the experimental parameters for the scratching and the angle of the inclined plane will be established, which can be used for fabricating inclined planes with high precision. Finally, the fabrication of the high precision and low damage blazed grating will be realized based on multiple-probe scanning technology. The project is expected to promote the domestic manufacture and application of blazed gratings, and bring the leap-forward development of equipment manufacturing and advanced scientific instruments in China.

闪耀光栅衍射效率高，能够极大地提高光栅测量系统的灵敏度、分辨率和测量范围，是促进精密制造水平提升的核心功能部件。《中国制造2025》将高精度光栅的制造列为研发重点。传统加工闪耀光栅的方法尚存不足，如机械刻划法导致闪耀面粗糙度大，全息离子束刻蚀的光栅轮廓难以控制等，亟待发展创新的加工方法。为此，本项目拟基于摩擦诱导加工方法在斜面加工方面的优势，研究提出闪耀光栅的高精度、低损伤加工的新方法。拟首先探明影响材料表面机械刻划变形层的形成及其选择性刻蚀的关键参数，研究揭示变形层的形成规律和选择性刻蚀机理；在此基础上，通过对其摩擦诱导选择性刻蚀过程的精确调控，建立摩擦刻划参数与斜面角度的对应关系，实现光栅斜面的高精度可控加工；最后，基于多针尖扫描技术，实现高精度、低损伤的闪耀光栅加工。通过本项目的研究，有望推进闪耀光栅的自主制造和应用进程，实现我国装备制造和先进仪器等领域的跨越式发展。

闪耀光栅作为精密制造、光学仪器、高性能显示等领域的重要功能部件，其制造技术倍受国内外研究人员关注。我国的闪耀光栅制造水平依然较低。本项目聚焦于研究和揭示摩擦诱导选择性刻蚀原理，据此开展闪耀光栅的加工研究。主要研究内容可概述为：揭示了摩擦诱导变形层的形成规律及其选择性刻蚀机理；阐明关键加工参数（刻蚀剂、温度、晶面等）对光栅斜面形成的影响规律，据此实现不同角度斜面的加工；搭建了高精度、大面积刻划加工设备，初步建立了基于摩擦诱导选择性刻蚀的闪耀光栅加工新方法。.首先，考察单一实验条件或环境工况下的单晶硅表面的摩擦诱导变形层形成规律（如变形层的厚度、晶格类型等），对摩擦刻划区域进行原位高分辨分析，通过高分辨透射电镜（HRTEM）、微区 X-射线光电子能谱（XPS）等获取晶体微观结构和化学成分特征。据此探明了单晶硅划痕损伤形式与关键因素的对应关系，并将这些因素组合，实现对损伤变形的进一步控制。其次，通过解耦的方法，系统研究单一损伤形式（如氧化物、非晶、位错等）在选择性刻蚀过程刻蚀规律，进而揭示摩擦诱导变形层选择性刻蚀机理。在上述基础之上，通过建立刻划、刻蚀参数与加工结构参数之间的对应关系模型，实现了摩擦诱导选择性刻蚀可控加工。特别地，商用的扫描探针显微镜难以实现大面积加工，且其探针难以在酸碱环境中扫描（探针会被刻蚀），严重阻碍了摩擦诱导选择性刻蚀加工方法的应用；鉴于此，成功设计并搭建了完全具有自主知识产权的高精度、大面积刻划加工设备（目前正在申报国家发明专利及软著权）。最后，在实现摩擦诱导变形层的可控制备和阐明摩擦诱导变形层选择性刻蚀基础之上，建立了摩擦刻划参数与斜面角度的定量关系，实现了角度2.5°闪耀光栅斜面的加工，发展了闪耀光栅加工新方法。另外，基于本项目摩擦诱导选择性刻蚀方法及所搭建的设备，实现了加工混合尺度纳流控芯片、微纳光学结构（含圆光栅、光学超构等）、表面增强拉曼衬底等加工，进一步拓展了扫描探针技术的应用。