Device for correcting illumination homogeneity

Abstract

The invention provides a lighting evenness correcting device arranged near a mask plate or near the optical conjugate planes of the mask plate. The device comprises a plurality of correcting component pairs arranged on the cross section of an illuminating beam, wherein the correcting component pairs are arranged at intervals in a non-scan direction and are overlapped in scanning direction; moreover, the correcting component pairs comprises a first correcting component inserted into a rectangular illumination field in scanning direction and a second correcting component inserted into the rectangular illumination field in a direction opposite to the scanning direction; the first correcting component and the second correcting component are in the shape of parallel flat plates on the section of the scanning direction and light beam transmission direction, and can respectively complete at least one dimensional motion in the scanning direction; both correcting components are provided with opposite transmittance distribution changing with position. The invention can prevent light leakage and shadow caused by the gap formed between adjacent correcting components; meanwhile, the invention can control the distribution of integral energy in the scanning direction and the evenness of the entire illumination field.

Description

technical field [0001] The invention relates to an illumination uniformity correction device applied in a photolithography system. Background technique [0002] Photolithography is an important process in semiconductor manufacturing, which precisely transfers the pattern on the mask to the substrate (such as: silicon wafer). In a lithography system, an illumination system is included between the laser source and the mask to generate the desired illumination pattern and illumination field distribution. In lithography, it is required that the illumination field generated by the illumination system is as uniform as possible, and the uniformity error is as small as possible, so that the entire illumination beam can be evenly irradiated on the mask and evenly projected onto the substrate. Illumination uniformity affects linewidth uniformity across the exposure field. [0003] A step-and-scan lithography system is a typical lithography system, which has a rectangular illuminatio...

AI Technical Summary

Problems solved by technology

Although the above-mentioned light leakage and shadow effects can be eliminated by using this kind of compensation plate with transmittance distribution, it is necessary to add an additional compensation plate, and the transmittance distribution of the compensation plate needs to correspond to all the gaps of the correction element, which will inevitably increase the correction system. the complexity

Images