Method and device for determining light polarization ratio degeneracy degree in photoetching objective lens optical design

Abstract

The invention discloses a method and device for determining the single light specific polarization ratio degeneracy degree. The method for determining the single light specific polarization ratio degeneracy degree comprises the steps that according to the image quality requirement for a photoetchingprojection objective lens, a film system is designed, and according to the designed film system, a practical sample is coated with a film; the sample coated with the film is tested, a Mueller matrix at different angles is determined, and the function relation of each matrix element to angles is fitted; by means of the fitted function relation of the Mueller matrix elements to angles, the specific polarization degeneracy degree corresponding to single light is worked out. The problem that the polarization characteristics cannot be predicted in traditionalphotoetching projection objective lens development, only post-measurement can be performed after objective lens manufacturing is completed is solved, and optical design stage polarization ratio degeneracy degree evaluation is achieved.

Description

Technical field [0001] The invention belongs to the field of optical design, and in particular relates to a method and a device for determining the degradation degree of a specific polarization ratio of a single light beam in the optical design of a lithography objective lens. Background technique [0002] What modern lithography technology is constantly pursuing is the continuous reduction of the feature size of lithography lines. In order to achieve this goal, many measures have been taken in the prior art, such as reducing the exposure wavelength and increasing the numerical aperture of the lithographic projection objective. When entering the 65nm and below nodes, in order to further improve the resolution of the system and achieve the purpose of reducing the feature size of the lithography line, polarized illumination must be used, that is, the incident light entering the projection objective must be a specific polarization state (x, y direction) Polarization), and after pas...

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Problems solved by technology

[0006] In order to solve the unpredictable technical problem of the specific polarization ratio degradation degree of any single beam of light in the joint simulation design process of the current lithography projection objective lens, the present invention proposes a method and device for determining the specific polarization ratio degradation degree of a single beam of light

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