Photolithography exposure device for implementing off-axis illumination by using free-form surface lens

Abstract

The invention discloses a photolithography exposure device for implementing off-axis illumination by using a free-form surface lens. The photolithography exposure device comprises a laser source, a beam expander, a free-form surface lens beam shaper, a filtering diaphragm, a varifocal optical system, an optical integrator, a collimation optical system, a field diaphragm, a relay optical system, a mask, a photolithography projection objective and photoresist, wherein the relay optical system comprises a front lens group, a middle reflection lens and a rear lens group; the position of the filtering diaphragm and the position of the front surface of the optical integrator form a pair of conjugate positions of the varifocal optical system; the position of the rear surface of the optical integrator and the position of the field diaphragm form a pair of conjugate positions of the collimation optical system; the position of the field diaphragm and the position of the mask form a pair of conjugate positions of the relay optical system; and the position of the mask and the position of the photoresist form a pair of conjugate positions of the photolithography projection objective. The photolithography exposure device has the advantages of good shaping effect and high energy utilization rate.

Description

technical field [0001] The invention relates to the technical field of lithography, in particular to a lithography exposure device which adopts a free-form surface lens to realize off-axis illumination. Background technique [0002] Photolithography is a key technology that promotes the rapid development of the semiconductor industry. It replicates the structural pattern of the integrated circuit on the mask to the silicon wafer coated with photoresist through the exposure device and the lithography projection objective lens. In the lithography exposure device, resolution enhancement technology (such as off-axis illumination) can be used to improve the lithography resolution and improve the depth of focus, so the performance of the lithography exposure device determines the performance of the projection lithography system. [0003] A lithography exposure device generally includes several main parts of a beam expander, a beam shaper, a zoom optical system, an optical integrat...

AI Technical Summary

Problems solved by technology

Similar to the fly-eye lens in the illumination system, to achieve a high uniformity off-axis illumination mode requires the use of a double-row or even multi-row microlens array, and at the same time reduce the size of the microlens, which undoubtedly affects the position of the lithography exposure system. Calibration puts forward higher requirements and also increases the complexity of lithography exposure equipment

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