Wave aberration detection device for optical system

Abstract

The invention discloses a wave aberration detection device for an optical system. According to the wave aberration detection device, lights emitted by a light source are evenly projected onto an object plane of the optical system by virtue of an illumination module. A pinhole array is positioned on the object plane of the optical system, and has the functions of spatial extension and spatial division. A shearing grating is installed on an image plane of the optical system. The function of phase shift can be realized by means of driving the shearing grating to move horizontally by a fine moving stage. By virtue of a collimating optical lens group, the concentric spherical wave shearing carrying the wave aberration information of the optical system is converted to plane wave shearing. The shearing interferogram light field information in the process of phase shift is recorded by a detector. By virtue of the pinhole array, the luminous energy of the detected system is improved; by virtue of the grating, shearing interference is realized; phase shift is performed by the horizontal movement of the grating; the sphere interference is converted to plane interference by virtue of the collimating optical lens group, so that the error happening when a plane detector receives sphere interference is eliminated and therefore, the wave aberration of the optical system can be detected at high precision.

Description

technical field [0001] The invention relates to a wave aberration detection device of an optical system, in particular to high-precision detection of wave aberration of a photolithography projection objective lens. Background technique [0002] Optical lithography is the most dominant production method of modern VLSI. With the development of needs, optical projection lithography is currently the most effective method for large-scale and low-cost production of large-scale integrated circuits. This technology has high production efficiency and mature and stable technology. Widely used in flat panel display, semiconductor lighting and other semiconductor industries. With the development of very large scale integration (VLSI), its integration level is getting higher and higher, and its key dimensions are becoming smaller and smaller. Now the key dimensions of mainstream electronic products are all at 28nm, and they are developing towards 22nm large-scale and low-cost. . This ...

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Problems solved by technology

[0007] In order to overcome the defects of the detection device in the above-mentioned patents and improve the detection accuracy, the purpose of the present invention is to provide an optical system wave aberration measurement device, which can eliminate the low light energy energy, poor contrast of the image plane, and the spherical surface received by the plane detector during the detection process. Receive errors and other shortcomings caused by interference fields, thereby improving detection accuracy and reducing detection time

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