互连芯片化学机械抛光材料去除的仿真分析

针对互连芯片化学机械抛光去除机理的认知不足,假设金属材料弹塑性变形连续,对单磨粒划擦互连芯片的材料去除进行了数值表征.通过芯片应力分布和工艺参数对材料去除率分析发现:平均法向力大于平均切向力;滑动摩擦系数、材料去除率随抛光速度增加而增加;当抛光速度为10~12 mm·s~(-1)时,粒径为30 nm的磨粒材料去除率最大;当工作载荷为6μN,抛光速度为6~10 mm·s~(-1)时,粒径为30 nm的磨粒材料去除率略低,粒径为60 nm的磨粒的材料去除率最大.

Simulation analysis of chemical mechanical polishing material removal of interconnection chip

In order to study material removal mechanism of chip in process of Chemical Mechanical Polishing . Based on contact mechanics that the contacting asperity is continuous ,and the material removal of single abrasive particle and the dynamic analysis of the contact process using ABAQUS finite element software is carried out. Through the analysis of the stress distribution of the chip and the process parameters on the material removal rate, it is found that the average normal force is larger than the average tangential force. The sliding friction coefficient and material removal rate increase with the increase of polishing speed. When the polishing rate is 10~12mm/s and the particle size is 30nm, the material removal rate (MRR) of abrasive is the maximum. When the working load is 6000nN, the MRR of the particle size of 30nm with the polishing speed of 6~10mm/s is slightly lower. When the particle size is 60nm, the MRR is the maximum. Through the research on the removal mechanism of CMP material, the mechanical effect on the MRR is controlled, which lays a foundation for further revealing the mechanism of the removal of chemical mechanical polishing material.