OPC correction method

Abstract

The invention discloses an OPC (Optical Proximity Correction) method, which comprises the following steps of: 1, providing an original layout in which a transition region of dense graphs and isolated graphs exists, and in which more than two structures with semi-isolated line ends aligned to aligned straight lines exist; 2, finding all aligned straight lines and corresponding semi-isolated line ends; step 3, pre-adjusting the semi-isolated line ends, namely, extending or shortening to adjust the side surface positions of the semi-isolated line ends, so that a first distance is formed between the side surfaces of two adjacent semi-isolated line ends aligned to the aligned straight line, and a second distance is formed between the side surfaces of two adjacent semi-isolated line ends aligned to the aligned straight line; increasing a process window of OPC correction of the dense pattern close to the semi-isolated line end by increasing the first interval; the original layout becomes an intermediate layout after being subjected to semi-isolated line end adjustment; and 4, carrying out OPC correction on the intermediate layout. According to the invention, the OPC process window of the dense pattern close to the semi-isolated line end alignment position can be improved.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit manufacturing method, in particular to an optical proximity correction (OPC) method. Background technique [0002] In the photolithography process, the pattern structure corresponding to the layout on the reticle (Mask) will be projected into the photoresist through the exposure system and form the corresponding pattern structure in the photoresist, but due to the optical The reason or the chemical reaction of the photoresist, there is a deviation between the pattern structure formed in the photoresist and the pattern structure on the mask plate. This deviation needs to be modified in advance on the pattern structure on the mask plate through OPC correction. When the OPC-corrected mask is exposed, the pattern structure formed in the photoresist will be consistent with the designed pattern structure and meet the production requirements of the process. [0003] In the graphic structure of the l...

AI Technical Summary

Problems solved by technology

[0006] However, in the case of multiple quasi-isolated line ends, that is, semi-isolated line ends, aligned on one line, due to the optical / photoresistive phenomenon of shortened line ends, the line ends need to be corrected a lot outward, and the aligned line ends will be generated during OPC correction. Simultaneous external expansion and mutual conflict, resulting in serious squeeze on the dense graphic area in the middle from both sides, so that pitch loose cannot completely solve the problem of poor process window and easy disconnection in the middle area

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