Reflection type beam splitting raster and interference photolithographic system

Abstract

The invention discloses a reflection type beam splitting raster and an interference photolithographic system. The reflection type beam splitting raster comprises a raster groove-shaped area located on a reflection face and a light blocking area located on the periphery of the raster groove-shaped area. The raster groove-shaped area comprises raster structures which are distributed periodically. Each raster structure comprises a groove-shaped reflection face and a non-reflection face. An inclined angle is formed between the groove-shaped reflection face and a raster base face. The reflection type beam splitting raster can realize largest modulation on +-1-level light, and enables reflected beam splitting light to have a highest energy utilization rate. An interference pattern obtained through the reflection type beam splitting raster has good boundary quality, is capable of finishing precise spliced patterns, and enables the large-width interference photolithographic technology to be improved remarkably.

Description

technical field [0001] The invention relates to the technical field of photolithography, in particular to a spectroscopic grating used in the interference photolithography technology and an interference photolithography system formed by using the spectroscopic grating. Background technique [0002] Interference lithography is an important branch of lithography, which has received extensive attention in recent years. The main advantage of interference lithography is the high pattern resolution that can be achieved. When the wavelength λ and numerical aperture NA of the optical system are fixed, the minimum linewidth that the interference optical system can obtain is λ / (4NA), which is 1 / 2 of the ordinary projection imaging optical system. In addition, the optical path of interference lithography is simple, and the pattern produced has accurate cycle and good uniformity. [0003] There are two typical optical path schemes in interference lithography. Optical path scheme one ...

AI Technical Summary

Problems solved by technology

Generally suitable for optical laboratories, not for optical processing equipment

Second, the lithography format is limited

If the aperture of the beam expander is to be increased, the manufacturing difficulty and cost will increase significantly

Third, the pattern quality of the edge of the photolithographic area is poor

[0018] First: ±1 order diffraction efficiency needs to be improved

Second: Sufficient suppression of useless diffraction orders (orders 0 and above 2) cannot be achieved

Its exposure area is not easy to achieve precise splicing exposure, which limits the solution's application in large-format lithography

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