| The lithography machine is a high-end product integrating light,machine and electricity,and the projection objective is an important part of the lithography machine.In order to meet the image quality required by the lithography system and reduce the impact of factors such as processing and assembly of parts and ambient temperature on the lithography system,the projection objective of the lithography machine is a multi-layer lens structure,and its installation and positioning need to achieve nano-level accuracy.Therefore,the posture adjustment of the projection objective lens group needs to be completed by a micro-displacement mechanism,and the accuracy of the measurement system of the adjustment mechanism is particularly important.The measurement system of the adjustable mechanism of objective lens studied in this paper takes a capacitive sensor as the measuring element and calibrates its measuring element with a dual-frequency laser interferometer.Since the measurement direction of each sensor of the system does not correspond to the movement direction of the objective lens,it is necessary to decouple the measurement system of the capacitive sensor and the laser interferometer.This paper proposes an algorithm for calibration,an adaptive hybrid moth-flame optimization algorithm.Through simulation software,the proposed algorithm and each classic optimization algorithm are compared and tested based on the CEC2015 function set.The test results show that the proposed adaptive hybrid moth-flame optimization algorithm is more suitable for calibration.This paper analyzes the error source of the capacitive sensor measurement system,and uses the adaptive hybrid moth-flame optimization algorithm to measure the data using a dual-frequency laser interferometer to perform the calibration simulation of the capacitive sensor.That is,the calibration algorithm is used toidentify the mechanical installation parameters of each capacitive sensor to avoid the installation error of the sensor and affect the accuracy of the decoupling model.After calibration,the error between the displacement of the objective lens output by the measurement system and the standard data meets the accuracy requirement of 10 ppm.Finally,this paper completes the software design of the host computer,and realizes functions such as human-computer interaction,data input and output,model calculation,and sensor calibration. |
