Interference lithography system and method based on spatial light modulator

Abstract

The invention relates to the technical field of lithography and provides an interference lithography system based on a spatial light modulator. According to the system, illumination beams transmitted from a light source become divergent light through a beam expander, the divergent light becomes parallel light through a collimating lens, the parallel light enters the spatial light modulator, the spatial light modulator performs image information modulation on the parallel light, a computer controls the spatial light modulator to display patterns, the parallel light becomes diffraction light after being subjected to diffraction splitting through the patterns displayed on the spatial light modulator, the diffraction light forms a spectral surface pattern on a back focal plane of a Fourier transform lens after passing through the Fourier transform lens, the diffraction light with required series is controlled to pass through by a Fourier transform spectral surface filtering baffle, and the diffraction light passing through the Fourier transform spectral surface filtering baffle is imaged with interference on a photoresist dry plate through an imaging mirror. The patterns displayed on the spatial light modulator are controlled through the computer, and the functions of image information modulation and diffraction splitting are simultaneously finished by the spatial light modulator.

Description

technical field [0001] The present invention relates to the technical field of photolithography, in particular to an interference photolithography system and method based on a spatial light modulator. Background technique [0002] Optical lithography technology can be used in the production of diffraction gratings, laser holograms, holographic optical components and other products, so it has been widely used in lithography plate making, anti-counterfeiting, micro-optics and other fields. An important factor in the rapid development of science and industry such as micro-processing technology and microelectronics industry. Many countries, including my country, are vigorously developing various optical lithography systems. [0003] Lithography technology has experienced the development from traditional contact exposure, to optical projection lithography, and to the current advanced interference lithography, imaging interference lithography, holographic lithography, atomic lith...

AI Technical Summary

Problems solved by technology

Among them, the one-dimensional grating used in the grating diffraction spectroscopic method has a fixed grating constant. In order to change the angle of the interfering light, for example, the method of replacing multiple one-dimensional gratings must be manually replaced and repeated exposures. Exposure only records a point and not an image, so it's very inefficient

However, the prism refraction spectroscopic method requires the use of multiple optical elements, multiple refraction and reflection of light, and the use of electromechanical systems to control the positioning and movement of these optical elements to control the beam direction, so the system is more complicated, and the moving speed of the optical elements is not fast. High, there is a large loss of light energy in multiple refraction and reflection

The prism refraction spectroscopic method can control the position of each component in the optical path to control the interference angle, so there is no need to manually replace the grating, but because the information recorded each time by the refraction method is also from a light spot formed by two single beams, Each exposure can only record one point instead of one image, so the efficiency is relatively low

Although there are lithography systems that have improved this, digital spatial light modulators are used for image information modulation of interference lithography systems, such as liquid crystal spatial light modulators (LC-SLM, Liquid CrystalSpatial Light Modulator), digital micromirrors (DMD, Digital Micro-mirror Device, etc., but there is still no simple and comprehensive method that can not only efficiently expose, but also realize image information modulation and diffraction spectroscopy at the same time

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