硅片化学机械抛光时运动形式对片内非均匀性的影响分析

Analysis of Influences on Within-wafer-nonuniformity of Motion Form in Wafer Chemical Mechanical Polishing

分析了目前几种常见的化学机械抛光机中抛光头与抛光垫的运动关系,针对不同的硅片运动形式,计算了磨粒在硅片表面的运动轨迹;通过对磨粒在硅片表面上的运动轨迹分布的统计分析,得出了硅片在不同运动形式下的片内材料去除非均匀性。从硅片表面材料去除非均匀性方面,对几种抛光机的运动形式进行了比较,结果表明,抛光头摆动式抛光机所产生的硅片内非均匀性最小。该研究为化学机械抛光机床的设计和使用中选择和优化运动参数提供了理论依据。

The motion relationship between wafer and the polishing pad in several familiar CMP machines were analyzed. According to different motion forms of wafer, the tracks of particles on wafer surface were calculated. Then by calculating the number of pixels of particle tracks in each small square on wafer surface, the WIWNU of wafer could be received in different motion forms. From WIWNU, the motion forms of wafer in three types of CMP machines were compared. As a result, the CMP machine that has the carrier with an arc oscillation produces the lowest WIWNU. The results can provide theoretical guide to use and design the CMP machines and optimize the motion variables of CMP.