Optical proximity correction method

Abstract

The invention relates to an optical proximity correction method which comprises the following steps: measuring a test pattern on the mask plate to obtain the graphic parameters of the test pattern; exposing according to the mask plate to obtain the graphic parameters formed by exposure; filtering the graphic parameters formed by exposure; according to the graphic parameters formed by exposure and the graphic parameters of the test pattern, obtaining the correction factor corresponding to the scanning form adopted by the exposure; and updating the original optical proximity correction model according to the correction factor, thereby obtaining the optical proximity correction model corresponding to the scanning form adopted by the exposure. The invention calculates the correction factor according to the parameter difference caused by different scanning forms adopted by exposure, and updates the original optical proximity correction model so as to obtain the updated optical proximity correction model, thereby enhancing accuracy of optical proximity correction.

Description

Technical field [0001] The invention relates to an optical proximity correction technology, in particular to an optical proximity correction method. Background technique [0002] With the increasing development of integrated circuits, the design size is getting smaller and smaller. Due to the phenomenon of light diffraction and interference, there are certain distortions and deviations between the lithography pattern actually obtained on the wafer and the mask pattern. This kind of error directly affects circuit performance and production yield. [0003] Optical Proximity Correction (OPC) is an effective method to eliminate this error. OPC can be divided into two types, one is rule-based OPC, and the other is model-based OPC. In order to adapt to the complexity of the design and make the correction more accurate, model-based OPC is increasingly adopted. Model-based OPC, in simple terms, is to correct the mask pattern, establish an optical proximity correction model, perform lith...

AI Technical Summary

Problems solved by technology

Due to optical effects, even though the same mask is used for exposure, due to different scanning forms, there will be differences in the actual patterns obtained on the wafer

Since the optical proximity correction model is established by measuring the pattern formed on the wafer, this brings problems. For example, for the same position or critical dimension, due to the different scanning forms used in the exposure process, two Different data, but the optical proximity correction model in the prior art does not consider such differences. The existing optical proximity correction model believes that for the same position or critical dimension, the image formed on the wafer after exposure and development is unique. , does not change with the scanning form

That is to say, the optical proximity correction model established in the prior art cannot make accurate corrections to the lithography process because the difference in actual imaging is not considered.

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