单点光学终点检测系统的研究

Study on the Single Point Optical Endpoint Detection

为了使CMP抛光精度更为精确,根据光学干涉原理设计了单点光学终点检测装置,给出了整套检测系统的简图和处理流程。在理想条件下,仿真单点光学检测的相干相位及反射率迹线,得出反射率迹线与抛光掉的透明层存在着函数关系,在实际条件核实了二者之间映射情况。采用九点测量后确认此函数条件下的单点光学终点检测具备高度的精确性,在此基础上推测了抛光头吸附晶圆以设定频率摆动情况下,光学传感器采集与处理数据的方法和过程。实际工艺操作证明,在综合运动条件下,其精度也达到要求。

Basing on the optical interference theory, a single point optical endpoint detection was designed. The whole detection system sketch and processes were presented. Under the ideal conditions, to simulate the coherent angle and the reflection track of the single point optical endpoint detection. Educing the relationship between the reflectivity trace and the removal rate, to compare with mapping in actual conditions, proving the single point optical endpoint detection with a high precision by nine-point measurement way. Conjecture the optical sensor acquiring and dealing with data under the wafer adsorbed by carrier and swing by the set frequency. Under the movement in the composite conditions, the single point optical endpoint detection meets the accuracy requirement.