Method for calibrating optical approach correcting model based on multi-photoresist active diffusion length

Abstract

An optical adjointing correction mode calibration method based on multi photo resist effective diffusion length comprises: measuring calibration data, using one-dimension diagram data calibration model to judge if the diagram is a one-dimension diagram or a two-dimension diagram, when it is a one-dimension diagram, using a one-dimension diagram data calibration photo resist model, and when it is a two-dimension diagram, using a two-dimension data calibration two-dimension photo resist model to judge if the sampling point simulation error is in a preset range, checking and outputting models. The invention respectively processes one-dimension diagram and two-dimension diagram, and uses the effective diffusion length according to actual diagrams, to reduce calibration error and improve calibration accuracy.

Description

technical field [0001] The invention relates to an optical proximity correction model calibration method, and in particular to an optical proximity correction model calibration method based on the effective diffusion length of multiple photoresists. Background technique [0002] Generally speaking, the lithography model always tries to describe each physical phenomenon of the lithography process as accurately as possible, but in many cases, due to the consideration of the calculation time of the whole chip, the optical proximity correction model (OPC) tool usually adopts semi-empirical The Diffuse Optical Imaging (DAIM) model is optimized to achieve faster calculation speed while ensuring a certain simulation accuracy. [0003] To simplify the overall calibration process, it is common practice in the industry to use the same resist effective diffusion length for all test patterns. On the other hand, with the continuous reduction of critical dimensions, the difference in the...

AI Technical Summary

Problems solved by technology

Figure 3 to Figure 5 is the calibration result of the classic optical proximity correction model, the vertical axis is the simulation error, and the horizontal axis is the graphic size. From the perspective of the entire error distribution, it is difficult to calibrate the one-dimensional and two-dimensional graphics well at the same time. The reason is A single photoresist effective diffusion length is used in the calibration process, and physically, the photoresist effective diffusion length varies from pattern to pattern, especially between 1D and 2D patterns, 2D patterns because photoacid from several Direction diffuses at the same time, so it has a larger effective diffusion length of the photoresist than the one-dimensional pattern, so it is difficult to calibrate the one-dimensional pattern and the two-dimensional pattern at the same time

Images