Laser interference lithography system using blazed grating

Abstract

The invention discloses a laser interference lithography system adopting a blazed grating. The laser interference lithography system includes a light source assembly, a beam expansion and collimation assembly, a multi-beam splitting and combining assembly, and a substrate stage. The light source assembly includes a coherent A light source, a first lens, a second lens, and a blazed grating. The laser beam emitted by the coherent light source passes through the first lens and the second lens in sequence, and then irradiates on the blazed grating after being refracted by a reflector, and is diffracted by the blazed grating. The light beam with the final wavelength equal to the first-order blaze wavelength exits through the small hole diaphragm, and then is divided into multiple coherent light beams after passing through the beam expander and collimation component, the multi-beam splitting and beam combining component, and converges and irradiates the beam on the substrate stage at the same time. substrate surface. The invention has the advantages of high light energy utilization rate and long coherence length, not only increases the flexibility and tolerance of optical path adjustment, but also reduces the requirement for the spectral line width of the laser light source, and expands the selection range of the laser light source.

Description

technical field [0001] The invention belongs to the technical field of laser interference lithography, and in particular relates to a laser interference lithography system using a blazed grating. Background technique [0002] The laser interference lithography system uses two or more coherent beams to combine and interfere in a certain way to produce a regular light intensity distribution in the spatial interference field, and to irradiate the surface of the substrate coated with photoresist. After exposure and development, a photoresist pattern corresponding to the interference pattern is produced in the photoresist layer, which can be regarded as a template for further etching a line array, dot matrix or hole array pattern on the substrate surface. Because laser interference lithography does not require expensive projection lithography objectives, conventional optical elements can be used to achieve micron-scale linear arrays, holes, and dot arrays through reasonable optic...

AI Technical Summary

Problems solved by technology

However, in order to take into account the photosensitive wavelength range of the photoresist, when building a laser interference lithography system, the selection range of the laser operating wavelength is limited. Within the limited selection range, its monochromaticity cannot be guaranteed, and some of them meet the requirements of the work. The coherence length of the laser required by the wavelength is only a few millimeters, which makes the layout of the optical path in the process of multiple light splitting and optical path turning and convergence in the interference lithography system very difficult. Even due to the limitation of the sensitive wavelength range of different photoresists, in It is difficult to find a laser source that meets the coherence length required by the optical path in certain wavelength ranges

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