光刻机硅片表面不平度原位检测技术

随着光刻特征尺寸的不断减小,硅片表面不平度对光刻性能的影响越来越显著.该文提出了一种新的硅片表面不平度的原位检测技术本文在分析特殊测试标记成像规律的基础上,讨论了测试标记的对准位置偏移量与硅片表面起伏高度的变化规律,提出了一种新的硅片表面不平度原位检测技术.实验表明,该技术可实现硅片表面不平度及硅片表面形貌的高准确度原位测量.该技术考虑了光刻机承片台吸附力的非均匀性对硅片表面不平度的影响,更真实反映曝光工作状态下的硅片表面不平度大小.与现有的原位检测方法相比,硅片表面不平度的测量空间分辨率提高了1.67%倍,可实现硅片表面形貌的原位检测.

An In-situ Method for Measuring the Wafer Flatness

As the critical dimensions in the semiconductor industry were shrinking,the influences of wafer flatness on lithographic performance became increasingly greater.Based on the imaging performance of the special marks,the relationships between alignment offsets and wafer height offsets were discussed.Then,a novel method for measuring the wafer flatness was presented.Experiments show that wafer flatness and the surface topography can be measured in situ by the technique with high accuracy.Taking into account of the nonuniformity of the adsorption power of vacuum chuck,wafer flatness can be measured with high accuracy.Compared to the level sensor based method,the spatial resolution is increased by 67%.The surface topography of the wafer can be obtained by the new method.