铜化学机械抛光材料去除机理的准连续介质法研究

Investigation for Material Removal Mechanism in Copper Chemical Mechanical Polishing with Quasi-Continuum Method

采用准连续介质力学方法研究了铜化学机械抛光过程的机械作用材料去除机理.模拟了不同大小磨粒在单晶铜工件上的磨削过程,分析了切削过程中工件内部材料变形、切屑的形成以及工件内部应力分布和切削力变化.研究结果表明,工件内部材料沿着与切削方向约45°变形形成剪切带,在剪切带区域伴随有位错、滑移等现象产生.磨粒较小时加工后的表面质量较差,磨粒较大时加工质量较好,但会造成工件内部较大的塑性变形与更深的残余应力分布.磨粒尺寸变化对于切向切削力影响不大.

Quasi-continuum method is adopted to investigate the material removal mechanism of chemical mechanical polishing of copper.The grinding process on the single crystal workpiece of abrasive particles of different sizes is simulated to analyze material deformation,stress distribution in the workpiece,chip formation and cutting force fluctuation.The result shows that shear zone is formed at 45° to the polishing direction with dislocations and sliding in the bulk.Smaller abrasive particles result in bad surface quality,while larger particles generate larger plastic deformation and deeper residual stress layer.Particle size exerts little influence on the tangential cutting force.