Edge placement error control and Mask3D effects in High-NA anamorphic EUV lithography

Setten, Eelco van; Bottiglieri, Gerardo; Winter, Laurens de; McNamara, John; Rusu, P.; Lubkoll, Jan; Rispens, Gijsbert; Schoot, Jan van; Neumann, Jens Timo; Roesch, Matthias; Kneer, Bernhard

doi:10.1117/12.2280624

Cited by 13 publications

(40 citation statements)

References 6 publications

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“…The mask topography and the optical properties of the mask materials are taken into consideration by S-Litho EUV while performing rigorous EMF (Electro Magnetic Field) simulations. A 20% central obscuration in an anamorphic projection mirror and CRAO (Chief Ray Angle at Object) of 5.355 o for EUV light source having a wavelength of 13.5 nm are the typical scanner inputs for simulations [7]. Our simulations make use of the Mo/Si Multi-Layer (ML) mirror mask model described by Makhotkin et al [8].…”

Section: Simulation Setupmentioning

confidence: 99%

“…TCE (also known as pattern shift through focus) signifies the lateral pattern shift of a feature as a function of focus and is represented in mrad or nm/um. When the CRAO is not perfectly parallel to the feature orientation, this causes an imbalance in the +1 and -1 diffraction order intensities, resulting in mask induced pattern shift through focus [16]. This results in pattern-dependent Edge Placement Errors (EPE).…”

Section: Setting Simulation Goals and Defining Target Valuesmentioning

confidence: 99%

“…A 10 mrad TCE implies 1 nm pattern shift per 100 nm of defocus. Eelco van Setten et al [16] suggest that the M3D induced TCE should be kept under 20 mrad. TCE and focus budget can be used to compute the M3D-induced overlay error using Equation 5 [16].…”

Section: Setting Simulation Goals and Defining Target Valuesmentioning

confidence: 99%

“…Maximal NILS, TCE within specified limits, balancing of diffraction order amplitudes with a minimum diffraction phase difference, and maximal throughput, are the important parameters that are considered when selecting the optimum absorber thickness. Our simulations aimed at Line and Space (LnS) patterns with a target CD (Critical Dimension) of 10 nm in a pitch of 20 nm (10nmP20) for High-NA (Numerical Aperture) 0.55 EUV lithography that matches the industry goal by 2028 [7].…”

Section: Introductionmentioning

confidence: 99%

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Optimizing EUV imaging metrics as a function of absorber thickness and illumination source: simulation case study of Ta-Co alloy

Thakare¹,

Delabie

Philipsen

2022

37th European Mask and Lithography Conference

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The imaging performance of a mask in EUV lithography is governed by the optical properties of the absorber material, namely the refractive index n and extinction coefficient k, and by its thickness. The imaging metrics viz. Normalized Intensity Log Slope (NILS), Telecentricity Error (TCE) and Best Focus Variation (BFV) through pitch, exhibit a tradeoff. In addition, the choice of illumination has a significant influence on these imaging metrics. Most of the previous studies have focused on either reflectivity or phase shift induced by the absorber to determine the optimum absorber thickness. The limitation of this approach is that the structure of the patterns on the mask is ignored. This simulation study is intended to facilitate the selection of the optimum absorber thickness with an emphasis on diffraction order analysis and the impact of illumination source shape using a case study of TaCo alloy. The behavior of imaging metrics is investigated as a function of absorber thickness in combination with illumination source shapes recommended in the literature. Maximal NILS, TCE within specified limits, balancing of diffraction order amplitudes with a minimum phase difference, and throughput criterion, are the important parameters that are considered when selecting the optimum absorber thickness. We evaluate and compare the through pitch imaging performance of TaCo alloy with recommended thicknesses, to that of the reference TaBN 60 nm absorber using Leaf shape Dipole (LDP), Inner Half Leaf shape Dipole (IHLDP) and Outer Half Leaf shape Dipole (OHLDP) for Line and Space (LnS) pattern with trench width of 10nm and the smallest pitch of 20 nm. The study confirms that TaCo alloy exhibits improved NILS and lower BFV compared to the reference TaBN 60 nm absorber.

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Section: Simulation Setupmentioning

confidence: 99%

Section: Setting Simulation Goals and Defining Target Valuesmentioning

confidence: 99%

Section: Setting Simulation Goals and Defining Target Valuesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Optimizing EUV imaging metrics as a function of absorber thickness and illumination source: simulation case study of Ta-Co alloy

Thakare¹,

Delabie

Philipsen

2022

37th European Mask and Lithography Conference

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“…Blocking of the diffracted light by the center obscuration in the high NA systems can potentially cause a further drop of the image contrast for certain pitches. 16 In some of the investigated use cases in this paper, we have provoked such scenarios to investigate the mask absorber performance for extreme and critical imaging conditions.…”

Section: D Mask Effects In Euv Lithographymentioning

confidence: 99%

Perspectives and tradeoffs of absorber materials for high NA EUV lithography

Erdmann

Mesilhy

Evanschitzky

et al. 2020

J. Micro/Nanolith. MEMS MOEMS

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Next-generation extreme ultraviolet (EUV) systems with numerical apertures of 0.55 have the potential to provide sub-8-nm half-pitch resolution. The increased importance of stochastic effects at smaller feature sizes places further demands on scanner and mask to provide high contrast images. We use rigorous mask diffraction and imaging simulation to understand the impact of the EUV mask absorber and to identify the most appropriate optical parameters for high NA EUV imaging. Simulations of various use cases and material options indicate two main types of solutions: high extinction materials, especially for lines spaces, and low refractive index materials that can provide phase shift mask solutions. EUV phase masks behave very different from phase shift masks for DUV. Carefully designed low refractive index materials and masks can open up a new path toward high contrast edge printing. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Source optimization for anamorphic magnification high-numerical aperture extreme ultraviolet lithography based on thick mask model

Wang

Wei

et al. 2022

2022 International Workshop on Advanced Patterning Solutions (IWAPS)

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Edge placement error control and Mask3D effects in High-NA anamorphic EUV lithography

Cited by 13 publications

References 6 publications

Optimizing EUV imaging metrics as a function of absorber thickness and illumination source: simulation case study of Ta-Co alloy

Optimizing EUV imaging metrics as a function of absorber thickness and illumination source: simulation case study of Ta-Co alloy

Perspectives and tradeoffs of absorber materials for high NA EUV lithography

Source optimization for anamorphic magnification high-numerical aperture extreme ultraviolet lithography based on thick mask model

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