Exposure latitude aware source and mask optimization for extreme ultraviolet lithography

Area of Science:

• Semiconductor Manufacturing
• Photolithography Technology
• Optical Engineering

Background:

• Extreme ultraviolet (EUV) lithography is a critical next-generation semiconductor manufacturing technology.
• High exposure latitude (EL) is essential for EUV lithography due to stringent light source stability requirements.
• Source and Mask Optimization (SMO) is a key technique for correcting imaging distortions in lithography.

Purpose of the Study:

• To propose a novel EL-aware SMO (ELASMO) method for enhancing EL in EUV lithography.
• To improve the process window and imaging performance of EUV lithography.
• To address the demand for greater stability and fidelity in EUV manufacturing.

Main Methods:

• Development of an ELASMO method incorporating a low-resist threshold sensitivity (LRS) penalty function.
• Application of the LRS penalty function within the SMO framework to optimize source and mask parameters.
• Comparative analysis against conventional SMO techniques to evaluate performance improvements.

Main Results:

• The ELASMO method significantly enhances aerial image contrast in EUV lithography.
• A notable improvement in exposure latitude (EL) is achieved using the proposed method.
• The process window is enlarged while maintaining high imaging fidelity compared to traditional SMO.

Conclusions:

• The ELASMO method effectively improves exposure latitude and process window in EUV lithography.
• This approach offers a viable solution for enhancing imaging performance and stability in advanced semiconductor manufacturing.
• ELASMO represents a significant advancement in optimizing EUV lithography processes.