Gravity deformation compensation device for optical element

Abstract

The invention discloses a gravity deformation compensation device for an optical element. The gravity deformation compensation device comprises the optical element, a deformable picture frame, a pair of annular electromagnets, a capacitor sensor and an upper cover board, wherein the deformable picture frame is in an integral structure formed by an inner ring of the picture frame, an outer ring of the picture frame and a support circular ring; the inner ring of the picture frame is fixedly connected with the optical element through an injection hole in the side wall; the lower part of the support circular ring contacts an outer picture frame boss to provide a support point; one annular electromagnet is arranged at the upper part of the outer ring of the picture frame; a vertical downward displacement is provided through repulsion between the electromagnets; and the outer frame of the deformable picture frame drives the inner frame to carry out an axial movement after being loaded, so that the optical element deforms; compensation of a rotational symmetry aberration is finally achieved; and the gravity deformation compensation device for the optical element has the advantages of being simple in structure, reasonable in design and the like.

Description

technical field [0001] The invention relates to high-precision optical element support structure design and surface shape compensation, and in particular provides an optical element gravity deformation compensation device. Background technique [0002] For the manufacturing process of large-scale integrated circuits, projection lithography is the most critical process, and a projection lithography machine is required. The projection objective lens is the core of the projection lithography machine, and its performance directly determines the lithography line. resolution. [0003] In order to ensure the extremely high imaging quality of the projection objective lens, the surface shape accuracy of each surface of the optical element after processing and coating is only allowed to be λ / 100, which is about 1nm~2nm (RMS). Generally speaking, in the visible waveband, when the optical lens diameter is small (Ф<100mm), the deformation caused by the lens's own weight is about λ / 20...

AI Technical Summary

Problems solved by technology

However, in a high-precision optical system such as a 193nm lithography projection objective lens, the maximum diameter of the lens reaches 300mm, and the error of a single lens caused by gravity deformation can reach tens of nanometers, which will seriously affect the imaging quality of the optical system

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