Mr. Yohan Choi Profile

Yohan Choi

Senior Product Manager at ASML

SPIE Involvement:

Author

Publications (17)

Proceedings Article | 27 October 2021 Presentation + Paper

Curvilinear masks: an overview

Yohan Choi, Aki Fujimura, Abhishek Shendre

Proceedings Volume 11855, 118550U (2021) https://doi.org/10.1117/12.2601916

KEYWORDS: Photomasks, Semiconducting wafers, Manufacturing, Vestigial sideband modulation, SRAF, Metrology, Inspection, Extreme ultraviolet, Design for manufacturability

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Curvilinear masks are coming. With multi-beam mask writers in production, leading edge mask shops now are able to write curvilinear masks in the same mask write times as any Manhattan masks [1, 2]. As Samsung and Luminescent showed long ago [3], curvilinear mask shapes produce the best wafer process windows. For 193i masks, curvilinear SRAFs have been demonstrated in reasonable time even with the traditional variable-shaped beam (VSB) writers with good wafer results. [4] It is widely anticipated [5] by the luminaries of the industry that curvilinear ILT shapes either are already or will be used at least for hotspots in some leading-edge layers before 2023 for both 193i and EUV masks. ILT solutions have previously focused on Manhattanizing the output to make it suitable for VSB writing, instead of using curvilinear or at least piecewise linear polygons to be specified for the desired mask shapes. With multi-beam mask writing being widely available for the leading-edge nodes, manufacturing curvilinear ILT shapes is now possible. But what about the rest of the mask making infrastructure? This paper introduces the session on curvilinear masks by surveying the constraints and considerations around introducing curvilinear masks to mask manufacturing. The other papers of the session will address the data volume and computational complexity issues with contour geometry in polygon-based processing of data. We take note of pixel-based manipulation of data being constant in run-time performance regardless of shape, whereas manipulation of contour geometry scales in run time based on vertex or edge count. This paper also reiterates that curvilinear MRC can be significantly less complex [6]. Other aspects of the mask infrastructure including metrology, inspection and repair will be discussed. The paper concludes with a brief discussion about curvilinear wafer targets, or curvilinear designs [7]. It suggests that allowing certain curvilinear targets can make designs more manufacturable and more resilient to manufacturing variation on the wafer, while decreasing power consumption, increasing clock speeds, and making designs smaller.

Proceedings Article | 26 March 2019 Presentation + Paper

EUV mask challenges and requirements for ultimate single exposure interconnects

Chris Progler, Michael Green, Ravi Bonam, Henry Kamberian, Mohamed Ramadan, Derren Dunn, Young Ham, Yohan Choi, Luciana Meli, Nelson Felix, Daniel Corliss, Bryan Kasprowicz

Proceedings Volume 10957, 109570L (2019) https://doi.org/10.1117/12.2515071

KEYWORDS: Photomasks, Semiconducting wafers, Image processing, Extreme ultraviolet lithography, Electron beam lithography, Stochastic processes, Inspection, Line edge roughness, Extreme ultraviolet, Optical proximity correction

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Proceedings Article | 3 October 2018 Paper

Hotspot analysis and empirical correction through mask and wafer technology harmonization

Yohan Choi, William Chou, Jeffrey Cheng, C. H. Twu, Adder Lee, Chih Hsuan Chao, Hsin Fu Chou, Sweet Chen, James Cheng, Colbert Lu, Josh Tzeng, Jackie Cheng, Hong Jen Lee, Michael Green, Mohamed Ramadan, Young Ham, Chris Progler

Proceedings Volume 10810, 108101K (2018) https://doi.org/10.1117/12.2501427

KEYWORDS: Optical proximity correction, Photomasks, Lithography

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Proceedings Article | 16 October 2017 Presentation + Paper

EUV mask manufacturing readiness in the merchant mask industry

Michael Green, Yohan Choi, Young Ham, Henry Kamberian, Chris Progler, Shih-En Tseng, Tsann-Bim Chiou, Junji Miyazaki, Ad Lammers, Alek Chen

Proceedings Volume 10450, 1045005 (2017) https://doi.org/10.1117/12.2281132

KEYWORDS: Photomasks, SRAF, Extreme ultraviolet, Manufacturing, Optical proximity correction, Extreme ultraviolet lithography, Metals, Inspection, Scanning electron microscopy, Metrology

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As nodes progress into the 7nm and below regime, extreme ultraviolet lithography (EUVL) becomes critical for all industry participants interested in remaining at the leading edge. One key cost driver for EUV in the supply chain is the reflective EUV mask. As of today, the relatively few end users of EUV consist primarily of integrated device manufactures (IDMs) and foundries that have internal (captive) mask manufacturing capability. At the same time, strong and early participation in EUV by the merchant mask industry should bring value to these chip makers, aiding the wide-scale adoption of EUV in the future. For this, merchants need access to high quality, representative test vehicles to develop and validate their own processes. This business circumstance provides the motivation for merchants to form Joint Development Partnerships (JDPs) with IDMs, foundries, Original Equipment Manufacturers (OEMs) and other members of the EUV supplier ecosystem that leverage complementary strengths. In this paper, we will show how, through a collaborative supplier JDP model between a merchant and OEM, a novel, test chip driven strategy is applied to guide and validate mask level process development. We demonstrate how an EUV test vehicle (TV) is generated for mask process characterization in advance of receiving chip maker-specific designs. We utilize the TV to carry out mask process “stress testing” to define process boundary conditions which can be used to create Mask Rule Check (MRC) rules as well as serve as baseline conditions for future process improvement. We utilize Advanced Mask Characterization (AMC) techniques to understand process capability on designs of varying complexity that include EUV OPC models with and without sub-resolution assist features (SRAFs). Through these collaborations, we demonstrate ways to develop EUV processes and reduce implementation risks for eventual mass production. By reducing these risks, we hope to expand access to EUV mask capability for the broadest community possible as the technology is implemented first within and then beyond the initial early adopters.

Proceedings Article | 28 March 2017 Presentation + Paper

Wafer hot spot identification through advanced photomask characterization techniques: part 2

Yohan Choi, Michael Green, Young Cho, Young Ham, Howard Lin, Andy Lan, Richer Yang, Mike Lung

Proceedings Volume 10148, 101480L (2017) https://doi.org/10.1117/12.2257676

KEYWORDS: Photomasks, Semiconducting wafers, 3D modeling, SRAF, Optical proximity correction, 3D metrology, Metrology, Critical dimension metrology, Finite element methods, Scanning electron microscopy, Yield improvement

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Proceedings Article | 20 October 2016 Paper

Mask manufacturing of advanced technology designs using multi-beam lithography (Part 1)

Michael Green, Young Ham, Brian Dillon, Bryan Kasprowicz, Ik Boum Hur, Joong Hee Park, Yohan Choi, Jeff McMurran, Henry Kamberian, Daniel Chalom, Jan Klikovits, Michal Jurkovic, Peter Hudek

Proceedings Volume 10032, 1003205 (2016) https://doi.org/10.1117/12.2247941

KEYWORDS: Photomasks, Manufacturing, Optical proximity correction, SRAF, Inspection, Metals, Optics manufacturing, Scanning electron microscopy, Logic, Lithography

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Proceedings Article | 5 October 2016 Paper

Wafer hot spot identification through advanced photomask characterization techniques

Yohan Choi, Michael Green, Jeff McMurran, Young Ham, Howard Lin, Andy Lan, Richer Yang, Mike Lung

Proceedings Volume 9985, 998521 (2016) https://doi.org/10.1117/12.2248678

KEYWORDS: Photomasks, Semiconducting wafers, Critical dimension metrology, 3D modeling, Optical proximity correction, Manufacturing, Metrology, Finite element methods, Mask making, Lithography

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Proceedings Article | 26 September 2016 Paper

Mask manufacturing of advanced technology designs using multi-beam lithography (part 2)

Michael Green, Young Ham, Brian Dillon, Bryan Kasprowicz, Ik Boum Hur, Joong Hee Park, Yohan Choi, Jeff McMurran, Henry Kamberian, Daniel Chalom, Jan Klikovits, Michal Jurkovic, Peter Hudek

Proceedings Volume 9985, 99850R (2016) https://doi.org/10.1117/12.2243407

KEYWORDS: Photomasks, SRAF, Optical proximity correction, Logic, Manufacturing, Metals, Inspection, Image processing, Information operations, Scanning electron microscopy

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Proceedings Article | 8 October 2014 Paper

Trends in mask data preparation

Aki Fujimura, Liyong Pang, Bo Su, Yohan Choi

Proceedings Volume 9235, 923508 (2014) https://doi.org/10.1117/12.2073368

KEYWORDS: Photomasks, Monte Carlo methods, Manufacturing, Critical dimension metrology, Optical proximity correction, Modulation, Vestigial sideband modulation, Backscatter, Convolution, Electrons

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Proceedings Article | 20 May 2006 Paper

The characterization of line-width in mask using spectrophotometry

Kyoung-Yoon Bang, Yo-Han Choi, Han-June Yoon, Hae-Young Jeong, Yong-Hoon Kim, Seung-Woon Choi, Hee-Sun Yoon, Woo-Sung Han

Proceedings Volume 6283, 62832H (2006) https://doi.org/10.1117/12.681791

KEYWORDS: Reflectivity, Spectrophotometry, Transmittance, Photomasks, Chromium, Critical dimension metrology, Refractive index, Optical lithography, Scatterometry, Inspection

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Proceedings Article | 5 November 2005 Paper

Optimized distributed computing environment for mask data preparation

Byoung-Sup Ahn, Ju-Mi Bang, Min-Kyu Ji, Sun Kang, Sung-Hoon Jang, Yo-Han Choi, Won-Tai Ki, Seong-Woon Choi, Woo-Sung Han

Proceedings Volume 5992, 599214 (2005) https://doi.org/10.1117/12.632427

KEYWORDS: Optical proximity correction, Computing systems, Photomasks, Distributed computing, Manufacturing, Resolution enhancement technologies, Databases, Data conversion, Data storage, Silver

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Proceedings Article | 10 May 2005 Paper

Repair simulation with image processing and artificial intelligence

Yo-Han Choi, Moon-Kyu Sung, Sang-Hyun Lee, Ji-Hyung Lee, Jin-Hong Park, Ji-Hyun Choi, Seong-Yong Moon, Sung-Woon Choi, Woo-Sung Han

Proceedings Volume 5752, (2005) https://doi.org/10.1117/12.599369

KEYWORDS: Neural networks, Neurons, Optical simulations, Image segmentation, Quartz, Edge detection, Artificial intelligence, Photomasks, Inspection, Image processing

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Proceedings Article | 27 December 2002 Paper

Fogging effect consideration in mask process at 50-KeV e-beam systems

Seung-Hune Yang, Yo-Han Choi, Jong-Rak Park, Yong-Hoon Kim, Sung-Woon Choi, Hee-Sun Yoon, Jung-Min Sohn

Proceedings Volume 4889, (2002) https://doi.org/10.1117/12.468100

KEYWORDS: Gaussian beams, Modulation, Vestigial sideband modulation, Critical dimension metrology, Beam shaping, Raster graphics, Electron beams, Photomasks, Mask making, Electrons

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Proceedings Article | 27 December 2002 Paper

Analytical approach to X-phenomenon in alternating phase-shifting masks

Jong Rak Park, Soon Ho Kim, Hojune Lee, Il-Yong Jang, Yo-Han Choi, Seung-Hune Yang, Jeong-Yoon Lee, Yong-Hoon Kim, Sung-Woon Choi, Hee-Sun Yoon, Jung-Min Sohn

Proceedings Volume 4889, (2002) https://doi.org/10.1117/12.468092

KEYWORDS: Photomasks, Phase shifts, Error analysis, Semiconducting wafers, Fourier transforms, Reticles, Wafer-level optics, Convolution, Image acquisition, Holmium

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Proceedings Article | 27 December 2002 Paper

Simple method for separating and evaluating origins of a side error in mask CD uniformity: photomask blanks and mask-making processes

Yo-Han Choi, Jong-Rak Park, Moon-Gyu Sung, Seung-Hune Yang, Soon-Ho Kim, Ho-June Lee, Jeong-Yun Lee, Il-Yong Jang, Yong-Hoon Kim, Sung-Woon Choi, Hee-Sun Yoon, Jung-Min Sohn

Proceedings Volume 4889, (2002) https://doi.org/10.1117/12.468099

KEYWORDS: Photomasks, Critical dimension metrology, Error analysis, Photoresist processing, Data modeling, Quantitative analysis, Chemically amplified resists, Integrated circuits, Semiconducting wafers, Etching

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Proceedings Article | 16 July 2002 Paper

Proximity effect correction optimization considering fogging and loading effects compensation

Seung-Hune Yang, Yo-Han Choi, Jong Park, Yong-Hoon Kim, Seong-Woon Choi, Jung-Min Sohn

Proceedings Volume 4689, (2002) https://doi.org/10.1117/12.473426

KEYWORDS: Critical dimension metrology, Etching, Beam shaping, Mask making, Backscatter, Scattering, Cadmium, Electron beam lithography, Modulation, Photomasks

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Proceedings Article | 22 January 2001 Paper

Improved process control of photomask fabrication in e-beam lithography

Byung-Cheol Cha, Jin-Hong Park, Yo-Han Choi, Jin-Min Kim, Woo-Sung Han, Hee-Sun Yoon, Jung-Min Sohn

Proceedings Volume 4186, (2001) https://doi.org/10.1117/12.410730

KEYWORDS: Photomasks, Critical dimension metrology, Electron beam lithography, Process control, Scattering, Control systems, Dry etching, Lithography, Semiconductors, Electronics

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Showing 5 of 17 publications

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