Method for calibrating the focal plane of opc and pwopc models

Abstract

The invention discloses a method for calibrating the focal plane of OPC and PWOPC models, collecting 1D structural graphic line width measurement data on the FEM wafer; forming a standard super line width measurement data format file; selecting the focal length sensitivity high graphics data; obtain a Poisson symmetric processed focal plane value; extract each group of Poisson symmetric processed image plane and focal plane values ​​and analyze the data to obtain the Poisson symmetric curve of the image plane-focal plane, and The polynomial fitting calculation is performed on the data trend line to obtain the function expressions of the image plane and the focal plane; the mathematical relationship between the image plane and the focal plane satisfying the Poisson symmetry relationship obtained by fitting is used to calibrate the focal plane of the OPC and PWOPC models. The invention can ensure the prediction accuracy of OPC and PWOPC models to the process window size under different exposure energy and focus plane conditions and the sensitivity to process parameter changes.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuits, in particular to a method for calibrating the focal plane of OPC (Optical Proximity Correction, optical proximity effect correction) and PWOPC (Process Window Optical Proximity Correction, non-nominal condition optical proximity effect correction) models. Background technique [0002] In the advanced semiconductor manufacturing process, the increasingly narrow process window has become a big challenge for the photolithography process. Correcting the design layout with a standard OPC model based on linewidth measurement data collected under standard exposure energy and focal plane conditions can only guarantee the accuracy of the standard conditions, but when the conditions change, the model cannot be made. accurate forecast. At this time, if the design layout of the product is very sensitive to process conditions, even if the established model is very accurate, it is difficult to...

AI Technical Summary

Problems solved by technology

Correcting the design layout with a standard OPC model based on linewidth measurement data collected under standard exposure energy and focal plane conditions can only guarantee the accuracy of the standard conditions, but when the conditions change, the model cannot be made. accurate prediction

At this time, if the design layout of the product is very sensitive to the process conditions, even if the established model is very accurate, it is difficult to apply it to mass production, because the process parameters in production will always fluctuate to a certain extent

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