非晶合金薄膜铜衬底的低损伤超光滑制备

Preparation of Ultra-smooth and Free-defect Copper Substrate for Amorphous Alloy Films

依据非晶合金薄膜生长对铜衬底的超光滑和低损伤要求,通过采用蓝宝石替代物实现进行式机械研磨。数值模拟结果表明能有效降低铜衬底的表面应力,试验测试表明替代物蓝宝石基片能有效地改善Rt值分布;通过设计开发动压浮离抛光基盘,利用液动压效应使得抛光时铜衬底与磨粒之间呈软性接触状态,改善了抛光的润滑状态。综合采用纳米压痕、NT9800白光干涉仪、透射电镜分析铜衬底表面及亚表层特性,测试分析结果表明,制备的铜衬底表面粗糙度Ra0.37 nm、Rt4.94 nm,亚表层材质致密均匀,亚表面晶格分布有序,晶格间的距离较一致,采用进行式机械研磨和动压浮离抛光方法对铜衬底实现了低损伤超光滑制备。

New lapping method using replacement of sapphire wafer is named as progressive mechanical lapping and verified according to ultra-smooth and free-defect for growth process of amorphous alloy films. Numerical simulation shows that introduce of sapphire wafer can effectively reduce surface stress for copper substrate, value of roughness Rt could be improved by progressive mechanical lapping process. Polishing substrate with hydrodynamic effect is designed and used to achieve soft contact and lubrication status between polishing abrasive grain and copper substrate. Surface and sub-surface characteristics are measured by nanoindentation, NT9800 white light interferometer and transmission electron microscopy, preparation of ultra-smooth surface with Ra0.37 nm and Rt4.94 nm and free-defcet with normal lattice distances, uniformity, density and non lattice dislocation could be finished by progressive mechanical lapping coulped with hydrodynamic float polishing processes.