Method for screening light intensity threshold value of SRAF developed on photoresist and predicting risk of exposure and development of SRAF

Abstract

The invention relates to a method for screening the light intensity threshold value of an SRAF developed on a photoresist and predicting the risk of the exposure and development of the SRAF and belongs to the field of semiconductor manufacturing techniques. According to the method, isolated features of which the characteristic dimensions are gradually increased are screened out from test layouts;the respective maximum light intensity values Imax of light which has passed through the screened test features are obtianed through analog simulation calculation on the basis of built OPC optical models under corresponding photoetching process conditions; the light intensity values Imax are gradually increased along with the increase of CD; the development conditions of the layouts with the gradually increased light intensity values Imax on the photoresist are checked on an exposed and developed silicon wafer; a light intensity value Imax corresponding to development on the photoresist is thelight intensity threshold value of the screened SRAFs developed on the photoresist. With the method adopted, the light intensity threshold of all the SRAFs developed on the photoresist under the photoetching process condition can be quickly and efficiently screened out under the condition of collecting less data, workload is reduced, and working efficiency is improved.

Description

technical field [0001] The invention relates to semiconductor manufacturing technology, in particular to a method for screening the light intensity threshold for developing SRAF on photoresist and a method for predicting the risk of exposure and development. Background technique [0002] In semiconductor manufacturing technology, photolithography exposure process is a common process in semiconductor manufacturing technology. The pattern on the mask is developed on the photoresist, and the light intensity reaching the surface of the photoresist through the mask is higher than the reaction threshold of the photoresist. Activation of the photosensitive components in the photoresist initiates a photochemical reaction. The light intensity threshold of the photoresist optical reaction has nothing to do with the type of pattern on the mask in theory, and the degree of photochemical reaction of the photoresist is related to the light intensity reaching the surface of the photoresist...

AI Technical Summary

Problems solved by technology

This method not only needs to collect a large amount of wafer data, but also reduces work efficiency

Moreover, the SRAF rule added in some layouts is relatively small, and none of the collected FEM data is exposed and developed on the photoresist, so the collected data cannot be obtained. The SRAF added in the layout is developed on the photoresist (extraprinting ) light intensity threshold, there is no light intensity threshold as a reference standard in the subsequent simulation SRAF extraprinting, it is impossible to predict the expression of SRAF on the photoresist in advance, and the optimal SRAF rule cannot be screened out, resulting in its inability to maximize the improvement Process window of the product

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