A Phase Diffraction Grating

Abstract

The present invention relates to the technical field of diffraction gratings, in particular to a phase type diffraction grating, comprising: a thin film substrate; a plurality of grid holes of the same shape and size uniformly opened on the thin film substrate, wherein the plurality of grid holes Arranged in a regular array on the film substrate; when the plurality of grid holes are arranged in a regular array, the lateral period is P x , the longitudinal period is P y ; The size of the grid hole and the lateral period P x and the longitudinal period P y It is in a preset ratio; the thickness of the thin film substrate is determined according to the value of the wavelength of the incident light, so that the absolute diffraction efficiency of the ±1st order is relatively improved, and the absolute diffraction efficiency of the 0th order and the first order is effectively suppressed.

Description

technical field [0001] The invention relates to the technical field of diffraction gratings, in particular to a phase type diffraction grating. Background technique [0002] Diffraction gratings generally use parallel black and white strip diffraction gratings. In spectral analysis, only ±1-order light is beneficial to analysis, but black and white strip gratings have the problem of multi-level diffraction, that is, there are high-level diffractions, and when applied in the extreme ultraviolet band , due to the serious absorption of materials in this band, there are great difficulties in process and image design. [0003] There are currently several single-order diffraction gratings, including inclined rectangular holes and random-sized circular holes, as well as single-order diffraction gratings with hexagonal holes, although they can all suppress high-order diffraction, so that only the 0th and ± 1st order, but the absolute diffraction efficiency of ±1st order is low, the...

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Problems solved by technology

[0002] Diffraction gratings generally use parallel black and white strip diffraction gratings. In spectral analysis, only ±1-order light is beneficial to analysis, but black and white strip gratings have the problem of multi-level diffraction, that is, there are high-level diffractions, and when applied in the extreme ultraviolet band , due to the serious absorption of materials in this band, there are great difficulties in process and image design

[0003] There are currently several single-order diffraction gratings, including inclined rectangular holes and random-sized circular holes, as well as single-order diffraction gratings with hexagonal holes, although they can all suppress high-order diffraction, so that only the 0th and ± 1st order, but the absolute diffraction efficiency of ±1st order is low, the highest is only 6.25%, and there are limitations in practical applications. How to obtain a diffraction grating that can improve the absolute diffraction efficiency while suppressing advanced diffraction is the current spectral analysis Problems to be solved in the field of technological development and application

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