Laser & Optoelectronics Progress, Volume. 59, Issue 9, 0922012(2022)
Measurement Techniques for Distortion of Lithography Projection Objective
One of the most critical elements influencing lithography overlay accuracy is the distortion of the lithography projection objective. The distortion causes transverse magnification of the objective to change with the increase in the field of view, and the pattern exposed on the silicon wafer is displaced relative to its ideal position, which causes overlay errors. During the alignment and use of the objective, distortion must be detected and optimized. At present, the distortion of advanced lithography projection optics is less than 1 nm, and its high-precision measurement is a difficult point in this field. This paper examines the principles and characteristics of three widely used lithography distortion detection technologies-exposure measurement, aerial image measurement, and wavefront measurement-as well as their future development potential. To increase the accuracy and speed of distortion detection, multichannel detection technology is an important development path for lithography nodes of 16‒19 nm and below 16 nm.
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Yisha Cao, Feng Tang, Xiangzhao Wang, Yang Liu, Peng Feng, Yunjun Lu, Fudong Guo. Measurement Techniques for Distortion of Lithography Projection Objective[J]. Laser & Optoelectronics Progress, 2022, 59(9): 0922012
Category: Optical Design and Fabrication
Received: Jun. 2, 2021
Accepted: Jul. 5, 2021
Published Online: May. 12, 2022
The Author Email: Tang Feng (tangfeng@siom.ac.cn)