Photoetching image obtaining method capable of improving imaging quality

Abstract

The invention discloses a photoetching image obtaining method capable of improving imaging quality and belongs to the technical field of semiconductor silicon wafer photoetching. The method comprises the following steps: according to a relationship between internal and external coherence factors sigma and sigma<out> of annular illumination and imaging distortion, determining sigma and sigma<out> capable of enabling the imaging distortion to be minimum by using a particle swarm algorithm, and reducing the imaging distortion of a photoetching image; enabling the initial binary mask pattern to pass through a photoetching imaging model to obtain a space image, determining a light intensity contrast gamma according to the light intensity distribution of the space image, delimiting parts with relatively high light intensity and relatively low light intensity, modifying the initial binary mask pattern, and reducing imaging fracture in a photoetching image; and finally, optimizing the modified initial binary mask pattern by using a gradient algorithm to obtain a real-value mask pattern, converting the real-value mask pattern into a binary mask pattern, and performing photoetching imaging by taking the binary mask pattern as a final initial binary mask pattern to obtain a final photoetching image, so the imaging distortion and imaging fracture are further reduced at the same time.

Description

technical field [0001] The present invention relates to an invention named as a photolithographic image acquisition method capable of improving imaging quality, which is used in DMD maskless photolithography and belongs to the technical field of semiconductor silicon wafer photolithography. Background technique [0002] During the lithographic imaging process of the DMD lithography machine, the initial binary mask pattern is used as the driving signal to drive the illuminated DMD imaging, and the lithographic image is obtained on the photoresist layer after passing through the projection optical system. DMD lithography machine has the characteristics of flexibility and high efficiency, and has become a key manufacturing equipment in some modern electronic and optical fields, such as circuit board manufacturing, micron-scale MEMS and MOEMS manufacturing, etc. The micromirror unit size of the DMD is 13.68 μm, the effective pixel size is 12.68 μm, there is a 1 μm interval betwe...

AI Technical Summary

Problems solved by technology

[0009] However, the existing technologies for improving the imaging quality of DMD maskless lithography are either only aimed at imaging fracture or imaging distortion, not only that, but also ignore the coupling effects of the two imaging quality problems on imaging quality , that is, the imaging fracture and the imaging distortion restrain each other, and this effect is greater than the respective effects on the image quality.

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