用于调焦调平测量系统中的硅片表面形貌模型

Model of Silicon Wafer Topography for Focusing and Leveling Measurement System

以硅片表面的平整度(flatness)和硅片表面的全场厚度范围(TTV)等参数为基础,建立了硅片表面的理论形貌模型。根据调焦调平测量系统指标等确定了调焦调平测量系统的有效频带,并设计了相应的滤波器。对硅片表面的理论形貌进行滤波后,得到用于调焦调平测量的硅片表面形貌的模型。由于该模型包括硅片表面在一个曝光视场内的模型和全场模型,并以SEMI标准和ITRS预测的相关参数为基础,因此不受实验条件影响,适用范围广,可用于调焦调平测量系统的模拟测试以及相关光刻工艺的分析。

A model of theoretical topography of a silicon wafer was established using its flatness and total thickness variation (TTV). A filter with a valid frequency band was designed to filter the theoretical topography of the silicon wafer, which the valid frequency band was decided by the work parameters of the focusing and leveling measurement system. The topography model of the silicon wafer used in the focusing and leveling measurement system was obtained after the theoretical topography of the silicon wafer was filtered. Because the topography model includes the surface profiles of both a site-scaled-wafer and a whole wafer and it is established using the SEMI standards and the parameters expected by ITRS, it is free of limitation of experimental conditions and can be widely applied in modeling measurement in the focusing and leveling measurement system and analyses related to lithography techniques.