Projection lens polarization aberration in-situ detection method of photoetching machine

Abstract

The invention discloses a projection lens polarization aberration in-situ detection method of a photoetching machine. A detection system used for the detection method comprises a light source, an illumination system, a mask bench, a mask comprising a detection mark, a projection lens, a working bench, an image sensor, a positioning system for the mask bench and a workpiece bench, a data processing system and a feedback control system; a polarization illumination mode is adopted for the detection method, and a large projection lens numerical aperture is selected for detection; then the imaging position deviation amount and the best focal plane deviation amount of the detection mark are measured by utilizing the image sensor; and the polarization aberration of the projection lens is calculated according to a calibrated polarization aberration flexibility coefficient. The projection lens polarization aberration in-situ detection method of the photoetching machine provided by the invention has the characteristics of simple structure of the detection system, short polarization aberration measurement time and large measurement range.

Description

technical field [0001] The invention relates to a lithography machine, in particular to an in-situ detection method for polarization aberration of a projection objective lens of a lithography machine. Background technique [0002] Lithography technology is the core technology to promote the miniaturization and high integration of semiconductor integrated circuits, and it affects the technical nodes that can be realized by the extremely large-scale integrated circuit manufacturing process. The step-and-scan projection lithography machine is an important equipment used in the lithography process, and the projection objective optical system is one of the important subsystems of the lithography machine. Under the conditions of large numerical aperture projection objective lens and polarized light illumination, the influence of polarization aberration of projection objective lens on lithographic imaging quality cannot be ignored. The typical effects of the polarization aberratio...

AI Technical Summary

Problems solved by technology

[0004] When using the prior art 1 and 2 to detect the polarization aberration of the projection objective lens, it is necessary to increase the diffusion plate for detection, and use a special grating to detect the mark, and the structure of the detection system is relatively complicated

In order to obtain the phase error on the entire pupil, in addition to changing the polarization angle, it is necessary to move the detection mask to repeat the measurement, and the measurement time is long

In addition, the measurement error increases with the increase of the phase delay in the polarization aberration, so the measurement range of the polarization aberration in the prior art 1 is limited to a certain extent

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