Molecular Modeling of EUV Photoresist Revealing the Effect of Chain Conformation on Line-Edge Roughness Formation.

Juhae Park,Hye-Keun Oh,Sung-Gyu Lee,Su-Mi Hur,Danilo De Simone,Myungwoong Kim,Yannick Vesters,Joren Severi

doi:10.3390/polym11121923

Juhae Park, Hye-Keun Oh + Show 6 more

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https://doi.org/10.3390/polym11121923

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Abstract

Extreme ultraviolet lithography (EUVL) is a leading-edge technology for pattern miniaturization and the production of advanced electronic devices. One of the current critical challenges for further scaling down the technology is reducing the line-edge roughness (LER) of the final patterns while simultaneously maintaining high resolution and sensitivity. As the target sizes of features and LER become closer to the polymer size, polymer chain conformations and their distribution should be considered to understand the primary sources of LER. Here, we proposed a new approach of EUV photoresist modeling with an explicit description of polymer chains using a coarse-grained model. Our new simulation model demonstrated that interface variation represented by width and fluctuation at the edge of the pattern could be caused by characteristic changes of the resist material during the lithography processes. We determined the effect of polymer chain conformation on LER formation and how it finally contributed to LER formation with various resist material parameters (e.g., Flory–Huggins parameter, molecular weight, protected site ratio, and Tg).

Highlights

Extreme ultraviolet (EUV) lithography technology [1,2] is the selected lithographic technology for sub-1x nm patterning [3]
During the subsequent exposure step, other possible sources of line-edge roughness (LER) were excluded by implementing an ideal image profile and assuming a perfectly controlled deprotection reaction (Figure 3a)
We demonstrated that polymer chain conformations significantly correlated to LER formation in EUV Chemically amplified resist (CAR)

Summary

Introduction

Extreme ultraviolet (EUV) lithography technology [1,2] is the selected lithographic technology for sub-1x nm patterning [3]. Important challenges need to be tackled to produce EUV for high-volume manufacturing (HVM), including source power availability, keeping the mask defect free, and inspection of the infrastructure for defects [4,5,6,7,8]. Source power availability for EUV HVM has significantly improved in the last few years. As of it has achieved reliable source operation with desired availability [8,9]. Issues with EUV photoresist, especially line-edge roughness (LER). Line-width roughness (LWR) reduction remain crucial challenges when increasing the resolution or the sensitivity.

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