液动压悬浮抛光新方法研究

Atomically smooth surface is a basis for nanofilm growth,it is sorely needed to improve the integrity during sample preparation process and surface quality and characterisitcs of nanofilm. This project is aimed to invent a new polishing method of atomically smooth surface and promote the development of nanfilm technology for its important scientific significance. According to the requirements of atomically smooth surface for nanofilm,a new polishing method named hydrodynamic suspension polishing method with uniform pressure distribution was developed, copper and silicon substrates will be used in this research work. Solid-liquid coupling function would be modeled according to wedge-shaped flow and parallel-flow types, numerical study would be carried out on the distribution of hydrodynamic flow field. Effect of structural parameters of polishing tool, rotating speed, liquid viscosity, shapes and size of constrained boundaries on uniform pressure distribution of hydrodynamic flow field would be studied by numerical and experimental methods. Atomically material removal mechanism would be presented by impact force of abrasive flow on substrate surface with molecular dynamics simulation method, and compare with surface integrities under different process parameters.Surface integrities such as surface roughness, structure morphology, residual stress and damaged layer would be measured by nanoindentation,nanoscratch,HRTEM,XRD,AFM,EBSD etc.,coupled with parameters opitimization work on polishing tool structure, shapes and size of constrained boundaries, parameters of suspension polishing. Mechanism and technology of new hydrodynamic suspension polishing will be promoted and related equipments with self-owned intellectual property rights will be designed for basis research of nanofilm.

原子级超光滑表面是高质量纳米薄膜生长的基石，提高衬底制备质量、改进制备方法有利于改善纳米薄膜表面质量及其特性，对于推动纳米薄膜技术发展具有重要的科学意义。 面向纳米薄膜生长衬底的原子级超光滑表面要求，提出了液动压均匀分布的悬浮抛光新方法。以铜和单晶硅试样为研究对象，建立楔形流场和平行流场的液固耦合作用模型，数值模拟液动压流场的分布，探索楔形抛光工具结构参数、抛光工具转速、液体粘度、约束边界形状及尺寸等对均匀液动压流场的影响规律，采用分子动力学研究磨粒流的冲击过程，揭示试样表面材料的原子级去除机理，试验研究不同工艺条件下的表面质量，综合利用纳米压痕/划痕、HRTEM、XRD、AFM、EBSD等测试表层形貌及亚表层的组织、残余应力、位错等，优化楔形抛光工具的结构、约束边界结构及悬浮抛光的工艺参数，建立液动压悬浮抛光加工理论与技术体系，为纳米薄膜的基础研究提供拥有自主知识产权的装备及技术。

原子级超光滑表面是高质量纳米薄膜生长的基石，提高衬底制备质量、改进制备方法有利于改善纳米薄膜表面质量及其特性，对于推动纳米薄膜技术发展具有重要的科学意义。.研制了工作稳定、适用于试样原子级超光滑少无应力加工的液动压悬浮抛光平台，主要包括驱动、升降、检测和主轴四大系统的主要零部件选型和设计校核。有望为薄膜生长衬底、纳米压痕测试分析提供新型研磨抛光机床和加工技术。.液动压悬浮抛光方法所提供的压力场较传统方法更为均匀，压力场的数值提升了5倍左右，其加工效率较传统方法有所提升，并且可获得表面粗糙度更小、表面形貌及晶格完整性更好的超光滑表面。.液动压悬浮抛光中磨粒是以接近水平的方式撞击工件表面，液动压悬浮抛光对工件表面的残余应力松弛起到了良好的效果，验证了ABAQUS数值模拟得到的工件表面应力松弛效应的正确性和完整性。