Method for determining sub-resolution assistance feature in OPC modeling

Abstract

The invention discloses a method for determining a sub-resolution assistance feature in OPC modeling. The method comprises the following steps: S1, selecting a first SRAP type which can be exposed ona wafer from an existing SRAF database; S2, selecting structural patterns of the first SRAF type, then selecting the structural patterns with a pattern period which can be added one and two structuralpatterns of the first SRAF type from the selected structural patterns, carrying out CDSEM measurement, collecting data, and building a model which can evaluate whether the SRAF type can be exposed onthe wafer; S3, simulating a territory database with series SRAF types by virtue of the model, so as to determine SRAF types which can not be exposed on the wafer; S4, selecting a second SRAF type from the SRAF types, and carrying out secondary verification on the wafer, so as to determine that the second SRAF types can not be exposed on the wafer; and S5, based on different structural patterns ofthe second SRAF type, collecting OPC model data and carrying out modeling. The method disclosed by the invention has the advantages that workload of OPC modeling early-stage preparation is effectively reduced, time for determining the SRAF type is shortened, resource utilization rate is improved and OPC modeling efficiency and accuracy are also improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor modeling, in particular to a method for determining sub-resolution auxiliary graphics in OPC modeling. Background technique [0002] The sub-resolution assistant feature (Sub-resolution Assistant Feature, SRAF) is a small graphic placed around the sparse design graphic, so that the sparse graphic looks like a dense graphic from an optical point of view, which helps to improve the sparse graphic in the depth of focus process window Image contrast at the edges. When exposed, they only scatter the light and will not be exposed to form patterns on the photoresist. Quickly and accurately determining the SRAF type that can improve the process window of sparse graphics without being exposed is an important parameter when collecting data for OPC modeling. [0003] see Figure 4 , Figure 4 Shown are the parameters commonly used to characterize the SRAF and main graphics. The SRAF graphic type is ...

AI Technical Summary

Problems solved by technology

[0009] The present invention is aimed at the traditional OPC modeling in which there are many types and graphics of SRAF that need to be observed and verified, the workload is large, the time is long, the efficiency is low, and when the process changes greatly, there is no empirical value to For reference, there are more types of SRAF that need to be searched, longer time-consuming, lower efficiency and other defects Provide a method for determining sub-resolution auxiliary graphics in OPC modeling

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