Device and method for carrying out field measurement on wave aberration of projection objective of photoetching machine adopting extended light sources

Abstract

The invention provides a device and a method for carrying out field measurement on the wave aberration of a projection objective of a photoetching machine adopting extended light sources, and the high-precision detection on the wave aberration of a projection objective can be realized by using the device and the method. The method comprises the following steps: when detection on the wave aberration of the projection objective is carried out, generating ideal spherical waves by using a round pinhole array on a first extended light source board above the projection objective, thereby eliminating the influence on the detection on the wave aberration of the projection objective of the photoetching machine caused by an illuminating system; and when system error calibration is carried out, generating ideal spherical waves by using a round pinhole array on a second extended light source board below the projection objective, thereby realizing the spatial filtering of the residual aberration of an illuminating system to be tested and the wave aberration of the projection objective. In the invention, the round pinhole array is provided with a plurality of pinholes, so that the utilization rate of the light source is high; meanwhile, the loss of beams produced in the process of beam propagation is small, thereby improving the accuracy of measurement.

Description

technical field [0001] The invention relates to a device for on-site measurement of the optical performance of a projection optical system, in particular to a device for on-site measurement of the wave aberration of a projection objective lens of a lithography machine using an extended light source for illumination, and belongs to the technical field of optical measurement. Background technique [0002] In the manufacturing process of large-scale integrated circuits, a photolithography machine is usually used to reduce and project the pattern on the mask onto a silicon wafer coated with photoresist through a projection objective lens. Such as figure 1 As shown, the existing lithography machine generally includes a light source 101 for generating a projection beam; an illumination system 102 for adjusting the partial coherence factor and polarization state of the beam emitted by the light source; a projection that can image a mask pattern on a silicon wafer 106 The objective...

AI Technical Summary

Problems solved by technology

However, the above-mentioned on-site measurement device has the following problems: First, it uses a pinhole mask containing a single pinhole to spatially filter the light beam. Due to the limitation of the light transmission area of ​​the pinhole, the light transmittance is poor and the utilization rate of the light source is low. , affecting the measurement accuracy

Second, it uses beam splitters and reflectors to change the optical path of the beam, and the loss of the beam is large during the propagation process

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