Separated strict modeling and calibration method for mask model and photoresist model

Abstract

The invention belongs to the technical field related to computational lithography in the semiconductor industry, and particularly discloses a separate strict modeling and calibration method for a mask model and a photoresist model. According to the method, a new thought of step-by-step mask model and photoresist model parameter decoupling calibration is adopted, the strictness of an optical imaging model and a mask model is emphasized and utilized, the complex and time-consuming strict solution of the near field of the thick mask with the complex two-dimensional structure is avoided, and the near field of the thick mask with the complex two-dimensional structure is strictly solved only from the strict solution of the near field of the mask with the one-dimensional or simple two-dimensional structure. Therefore, separate strict calibration and calibration of the photoresist model and the mask model suitable for a complex two-dimensional structure can be completed. Besides, on the basis of the calibration result of the separated mask model and the photoresist model, a joint iterative calibration method of the photoresist model and the mask model is provided, and the obtained calibration result can enable the model to better conform to the actual physical condition.

Description

technical field [0001] The invention belongs to the field of semiconductor photolithography, and more specifically relates to a separate strict mask model and photoresist model modeling and calibration method. Background technique [0002] In today's era, with the rapid development of information technology, the requirements for smaller, faster and more powerful chips are put forward, and the demand for miniaturization of integrated circuits is becoming stronger and stronger. Photolithography technology is the most critical link in integrated circuit manufacturing, which realizes the transfer of chip circuits from masks to photoresists, accounting for more than 35% of chip manufacturing costs. The lithography system mainly consists of four parts: a light source, a mask plate, an objective lens system and a wafer coated with photoresist. The light emitted by the light source passes through the transparent area on the mask plate and is collected by the objective lens system on...

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Problems solved by technology

However, since all parameters are mixed together, the changes of some parameters during the fitting process may not strictly conform to the physical conditions, and even overfitting often occurs.

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