X射线干涉光刻偏转聚焦系统热载影响与分析

为缩短实验前的等待时间，减小热辐射对光学元件的损伤以及热变形对实验的影响，充分利用同步辐射X射线获得稳定有效的实验结果，对X射线干涉光刻(XIL)光束线偏转聚焦系统进行了热结构耦合分析。针对上海光源(SSRF)的光源参数，计算偏转聚焦系统所受的热功率密度分布，在此基础上对偏转聚焦系统在相同载荷、不同边界条件下进行了瞬态热平衡分析，得到双柱面镜M1、M2达到热平衡所需的时间、温度分布，并做了比较分析。结果表明，对XIL光束线上偏转聚焦系统的M1、M2采用间接水冷方式可削弱热载效应，达到热平衡的时间分别由8677 s和7850 s缩短到960 s和840 s，最高温度分别由182.73 ℃和129.73 ℃降低到57.94 ℃和47.29 ℃，此时的最大面形误差分别为7.23 μrad和9.24 μrad，缩短了从开机到实验的等待时间，在提高实验效率的同时能够获得稳定有效的实验结果。

Analysis of Heating Effect on XIL Deflection Focus System

In order to shorten the waiting time before experiment, reduce the damage caused by heat radiation and lower the influence of thermal deformation on the experiment, thermo-mechanical analysis of deflection focus system is carried out by making full use of synchrotron radiation X-ray to obtain stable and effective experimental results. Based on the main parameters of Shanghai synchrotron radiation facility (SSRF), the thermal power density distribution absorbed by deflection focus system on X-ray interference lithography (XIL) line is calculated. Then dynamic thermal equilibrium analysis is carried out under the conditions: without water cooling, with water cooling and thermal radiation. Finite element analysis is used to perform the thermo-mechanical analysis of M1, M2 in order to obtain parameters such as the time required for thermal equilibrium and the temperature gradient distribution. Results indicate that the thermal load effect on M1, M2 of deflection focus system can be weakened by indirect water cooling structure. Thermal equilibrium durations of M1, M2 get dropped substantially from 8677 s and 7850 s to 960 s and 840 s, respectively. The highest temperatures reduce from 182.73 ℃, 129.73 ℃ to 57.94 ℃, 47.29 ℃, respectively. Meanwhile, the biggest slope errors are 7.23 μrad, 9.24 μrad, respectively. The waiting time from operating to experiment is shortened, which can improve the efficiency greatly and ensure steady and effective experimental results.