Light beam stokes parameter measuring device and measuring method

Abstract

The invention discloses a light beam stokes parameter measuring device and a measuring method thereof. The polarization measuring device is composed of a beam splitter prism group, a phase retarder array, a polarization analyzer, a photoelectric detector array and a signal processing system, wherein all units of the photoelectric detector array correspond to all units of the phase retarder array one by one. The measuring method is realized through the following steps: adopting the phase retarder array to replace the rotational phase retarder; according to the polarization direction of a to-be-measured light beam, adjusting the direction of a light-transmitting shaft of the polarization analyzer to be parallel to or vertical to the polarization direction of the to-be-measured light; measuring the polarization parameters of the to-be-measured light beam; processing data as per light intensity signals detected by the photoelectric detector array so as to realize the real-time high accuracy measurement of the light beam stokes parameters. Though adopting the method, the stokes parameters of the light beam can be measured in real time, and furthermore, the influences on the measurement accuracy of the light beam polarization state caused by the phase delay error of phase delaying devices, the fast-shaft direction error, the direction error of the light-transmitting shaft of the polarization analyzer and the extinction ratio error are reduced.

Description

technical field [0001] The invention relates to the measurement of beam Stokes parameters, in particular to a beam Stokes parameter measurement device and a measurement method. Background technique [0002] 193nm immersion lithography is the mainstream lithography technology at 32nm node. In the immersion lithography technology, some kind of liquid is used to fill between the last lens of the objective lens and the photoresist on the silicon wafer, so that the projection objective lens and the data aperture have been significantly improved. When the numerical aperture of the projection objective lens is close to 1 or When it is larger, the influence of the polarization state of illumination light on lithography imaging can no longer be ignored. Appropriate polarized light illumination can effectively improve the imaging contrast in a large numerical aperture lithography system. As the numerical aperture of the projection objective lens of the immersion lithography machine ...

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Problems solved by technology

At the same time, since the phase retarder array required by the device is a sub-wavelength grating, electron beam etching is used; due to the etching process, although the fast axis direction of the phase retarder can be etched accurately, the phase delay cannot be accurately etched. control, so that the device has a phase delay error, which brings a certain error to the Stokes parameter measurement system

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