Laser interferometric lithography system with application of blazed grating

Abstract

The invention discloses a laser interferometric lithography system with the application of blazed grating. The laser interferometric lithography system comprises a light source module, a beam spread collimation module, a multiple beam split and beam combination module and a substrate holder. The light source module comprises a coherent light source, a first lens, a second lens and blazed grating. A laser beam emitted from the coherent light source successively passes through the first lens and the second lens and then passes through a reflector to make a light path bend over, and light is illuminated on the blazed grating. A light beam with wave length being equal to first-order blaze wavelength after blazed grating diffraction passes through a small aperture to be emitted out, and then passes through the beam spread collimation module and the multiple beam split and beam combination module to be split into multiple coherent light beams. The multiple coherent light beams are simultaneously converged and illuminated onto the substrate surface on the substrate holder. The system provided by the invention has advantages of high efficiency of light energy utilization and long coherence length. Flexibility and tolerance for light path adjustment are enhanced, linewidth requirement of a laser light source is also reduced, and selection range of the laser light source is broadened.

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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