Device and method for aligning pinhole of point-diffraction interferometer

Abstract

The invention discloses a device and a method for aligning a pinhole of a point-diffraction interferometer, belonging to the technical field of optical precise debugging, namely a device and a method for aligning the pinhole of the point-diffraction interferometer provided to realize real-time monitoring of precise aligning and aligning states of a focusing spot and a diffraction pinhole in the point-diffraction interferometer. The device comprises a laser device, a laser beam expander, a first dispersion prism, a half-wave plate, a second dispersion prism, a third dispersion prism, a quarter-wave plate, a focus lens, a pinhole plate, a three-dimensional scanning and micro-adjusting mechanism, a first laser power meter, a second laser powder meter, a third laser power meter, a position detector and a computer. According to the device and the method disclosed by the invention, the aligning speed is increased; the pinhole aligning state is quickly aligned again when being monitored; power change of the laser device is detected by a sole laser power meter in the invention and the aligning state is reflected by a ratio of the laser power instead of an absolute value so that error judgment on the aligning state of the pinhole caused by laser power change is overcome.

Description

technical field [0001] The invention belongs to the technical field of optical precision adjustment, and relates to a precision alignment device and method for pinholes in point diffraction interferometers. Background technique [0002] In order to achieve the required resolution and critical size of the projection lithography objective lens, the wave aberration of the optical system needs to reach the diffraction limit. The extreme ultraviolet lithography works in the extreme ultraviolet band with a wavelength of 13-14nm, which requires the wave aberration of the optical system It should be less than 1nmRMS, and the surface deviation of a single mirror surface should be 0.25nmRMS. To achieve such high-precision optical processing, high-precision optical detection technology must first be realized. Conventional interferometric detection technologies such as Fizeau interferometer and Tieman interferometer are limited by the accuracy of the reference surface, and it is difficu...

AI Technical Summary

Problems solved by technology

[0007] Due to the different structures of the point diffraction interferometer when detecting the system wave aberration and the surface deviation of the detection element, the alignment technology of the point diffraction interferometer pinhole described in the above literature is only applicable to the point diffraction when detecting the system wave aberration Alignment of the interferometer, not suitable for pinhole alignment in the point diffraction interferometer when detecting the surface shape of the component

Images