基于磨粒晶界结合固着磨具的硬脆半导体衬底高效磨削方法研究

This proposal suggests a high efficient chemo-mechanical grinding process based on grain boundary cohension fixed abrasive tool, which meets the requirement from the planarization of hard-brittle semiconductor substrate. Grain boundary cohension fixed abrasive tool is able to enlarge the contact area between abrasive and workpiece, improve the wear property of abrasive tool, and enhance the chemical effect and mechanical effect, meanwhile develop the chemo-mechanical grinding process under high temperature, promote the atomic diffusion rate of solid phase reaction, and enhance chemical effect, and thus improve the machining efficiency. Through theoretical analysis, numerical simulation and experimental study, reveal the bonding mechanism, construct the structural model, propose the manufacturing method, realize the flexible control, and establish a comprehensive evaluation method of grain boundary cohension fixed abrasive tool; Propose the mechanism of chemical effect and mechanical effect under high temperature, optimize the process parameters, realize the relative balance between chemical and mechanical effect, and establish the chemo-mechanical grinding process of hard-brittle semiconductor substrate based on grain boundary cohension fixed abrasive tool with high efficiency and high quality. The proposal has important research significance and extensive application value for the planarization technology of semiconductor substrate.

针对硬脆半导体衬底平坦化加工的要求，提出一种基于磨粒晶界结合固着磨具的高效化学机械磨削加工方法。磨粒晶界结合固着磨具能够增大磨粒-工件之间的接触面积，改善磨具的磨损性能，增强化学作用和机械作用，同时开发高温化学机械磨削加工，提升固相反应的原子扩散速率，增强化学作用，从而提高加工效率。本项目通过理论分析，数值仿真和实验研究，揭示磨粒晶界结合固着磨具的结合机理，构建磨具的结构模型，提出磨具的制作方法，实现磨具性能的灵活调控，建立磨具性能的综合评价方法；提出高温磨削加工的化学作用和机械作用机理，优化工艺参数，实现化学-机械作用的相对平衡，建立基于磨粒晶界结合固着磨具的硬脆半导体衬底高效、高质量化学机械磨削加工方法。本项目对半导体衬底的平坦化加工技术具有深刻的研究意义和广泛的应用价值。

本项目针对硬脆半导体衬底的加工要求，提出一种基于磨粒晶界结合固着磨具的半导体衬底高效磨削加工方法。利用分子动力学仿真软件LAMMPS，在微观层面对球形纳米二氧化硅磨粒晶界结合固着磨具烧结过程进行模拟。仿真结果表明，二氧化硅磨粒粒径越大，升温速率越低，最终形成的烧结颈宽度越长。原子径向分布函数表明，烧结过程伴随着二氧化硅磨粒致密化。通过对二面角的测量，发现低升温速率更有利于烧结的进行。制备三氧化二铬和二氧化硅磨粒晶界结合固着磨具，三点弯曲实验结果显示磨具的弯曲强度随烧结温度的提高而增大。摩擦磨损试验结果显示三氧化二铬和二氧化硅磨粒晶界结合固着磨具的最佳烧结温度区间为600-650和1050-1100 ℃，且三氧化二铬相对于蓝宝石具有更强的化学活性。XPS定量分析结果表明三氧化二铬和二氧化硅与蓝宝石会发生固相反应，生产复杂的Cr-Al-O或Si-Al-O三元化合物。同时，温度的升高会加快原子扩散速率，从而提高固相反应速率。搭建化学机械磨削加工平台，实验结果显示600 ℃烧结的磨粒晶界结合固着磨具砂轮的材料去除率较传统的树脂结合剂砂轮提高17.5%，加工后蓝宝石的表面粗糙度Ra＜1 nm，且无明显亚表面损伤。因此，本项目成功开发了基于磨粒晶界结合固着磨具的蓝宝石高效磨削方法，为半导体衬底的高效、高质量加工奠定坚实的基础。