We investigated a high-precision grating interferometer displacement measurement system that can be applied to high-end immersion lithography machines and explained its composition and measurement algorithm. By analyzing the optical path variation caused by the installation error of the grating interferometer, we calculated the influence of the installation error on the displacement measurement. A displacement measurement model of a grating interferometer using three read heads was established, and the influence of the model coefficients on the displacement measurement model was analyzed. The simulation results show that, under the condition that the error of the measurement model in the X direction and the Y direction is <0.1 nm, the translation error of the read head should be within ±100 μm, and the relative rotation deviation between the two read heads or two gratings placed along the diagonal should be within ±50 μrad. The methods and results of studying the influence of grating interferometer installation error on the displacement measurement provide a theoretical basis for the application of a grating interferometer displacement measurement system in immersive high-end lithography scanners.

中文翻译：

---

光栅干涉仪安装误差对高精度位移测量的影响

我们研究了可应用于高端浸没式光刻机的高精度光栅干涉仪位移测量系统，并解释了其组成和测量算法。通过分析由光栅干涉仪安装误差引起的光程变化，我们计算了安装误差对位移测量的影响。建立了具有三个读取头的光栅干涉仪的位移测量模型，并分析了模型系数对位移测量模型的影响。仿真结果表明，在测量模型的X方向和Y方向误差<0.1 nm的条件下，读取头的平移误差应在±100μm以内，沿对角线放置的两个读取头或两个光栅之间的相对旋转偏差应在±50μrad之内。研究光栅干涉仪安装误差对位移测量影响的方法和结果为光栅干涉仪位移测量系统在沉浸式高端光刻扫描仪中的应用提供了理论依据。