Dr. Gek Soon Chua Profile

Dr. Gek Soon Chua

Principal Member of Technical Staff at GlobalFoundries

SPIE Involvement:

Author

Area of Expertise:

OPC/RET , mask specification , source mask optimisation , reticle haze management , mask data preparation , mask process correction

Profile Summary

Professional experiences include
1. Experience in Optical Proximity Correction (OPC), Resolution Enhancement Technologies (RET) & Advanced Mask Optimization (EUV Mask Process Correction, E-beam mask shot count reduction, Model-based Mask Data Preparation, Source-Mask Optimization (SMO) & Flexible-Mask Optimization (FMO))
2. Driving solution to optimize interactive factors such as OPC, fracturing method, enabling VSB with MPC & mask shot count optimization at same time
3. Lead cross functional teams for mask-related device yield loss issue, mask specification ownership, evaluation for OPC- and mask-related equipments & software
4. Environment expert on cross-Fab clean room environmental studies

Accolades include
1. Invited speaker at ebeam Initiative at PMJ 2012 for “Proof Point on MB-MDP and Wafer Quality Simulation”
2. Invited speaker at EMLC 2012 for “Optimization of mask shot count using MB-MDP and lithography simulation”
3. Invited speaker at ebeam Initiative at BACUS 2011 for “Optimization of mask shot count using MB-MDP and lithography simulation”
4. Awarded BACUS 2011 Best Poster Award (1st Place) for “Optimization of mask shot count using MB-MDP and lithography simulation”

Publications (25)

Proceedings Article | 17 October 2019 Presentation

Presentation

Design to silicon flow challenges for silicon photonics (Conference Presentation)

Ian Stobert, Karen Badger, Gek Soon Chua, Mohamed Gheith, Matthew Kinzler, Adam Smith

Proceedings Volume 11148, 111480S (2019) https://doi.org/10.1117/12.2539054

KEYWORDS: Photomasks, Silicon photonics, Photonics, Silicon, Optical proximity correction, Data corrections, Inspection, Mask making, Signal attenuation, Semiconducting wafers

Read Abstract +

Silicon Photonics design layouts require use of curved shapes, since many of the structures built to route light through silicon are designed to curve smoothly to minimize the loss of signal strength. The design-to-silicon flow involves steps like Design Rule Checking (DRC), Optical Proximity Correction (OPC), Mask Rule Checking (MRC), Mask Process Correction (MPC), mask data fracture, mask writing and mask inspection. All of these steps involve software and techniques that have evolved over decades of use for predominately orthogonal design geometries composed of vertical and horizontal edges. In many cases, these tools and process steps will perform poorly or fail if they are used on free form curvilinear layouts – unless changes are made to accommodate the curvilinear designs. In this paper, we describe challenges in various steps of the design-to-silicon flow associated with supporting curvilinear photonics design layouts. We first present two flow alternatives, which we call “manhattanization” and “free form”. The manhattanization flow is where angles or curved layout edges are converted to short vertical and horizontal fragments closely matching the design intent. The advantage of the manhattan approach is that DRC, OPC, MRC and MPC decks designed for use on orthogonal CMOS designs can be used on photonics content that has been manhattanized. We present examples of layouts where the manhattan approach causes problems in several phases of the tapeout flow. We also present an example of a free form tape out flow, with particular focus on the unique challenges faced in correcting for different wafer processing steps in the OPC recipes. We also discuss some of the existing literature offering ideas on how to best manage free form layouts in OPC and mask data preparation. Ultimately, the goal of these data operations is to enable creation of a photomask for use as a master template in the chip production; since these mask writers almost exclusively operate with rectilinear data, the designs must ultimately be Manhattanized. We will explore the benefits, challenges, and drawbacks to manhattanizaiton specifically during mask making as well. The latter portion of the paper presents some of the challenges faced in mask making for free form photonics designs. We discuss the role that MPC plays in photonics mask production, where many features are sufficiently large to make MPC unnecessary, and we look some examples of more advanced photonics designs where MPC may need to play a role. We explain the challenges in trying to define and enforce MRC rules on curvilinear content to ensure mask inspectability and manufacturability. We describe the design and use of a programmed defect inspection test mask designed to formulate some simple MRC rules for free form mask designs. We demonstrate the linkage between curvilinear DRC and MRC, as the techniques and challenges faced in both areas are very similar. We also explore the relationship between the manhattanization and mask operational and performance metrics, such as data volume, write time, image fidelity, and design intent fidelity when going from manhattanized mask shapes to free form mask shapes for photonics layouts.

Proceedings Article | 26 September 2019 Presentation + Paper

Presentation + Paper

MPC simplification for established model-based mask process correction solutions

Gek Soon Chua, Weijie Lu, Yee Mei Foong, Weilong Wang, Todd Bailey, Paul Ackmann, Jed Rankin

Proceedings Volume 11148, 111480H (2019) https://doi.org/10.1117/12.2536745

KEYWORDS: Photomasks, Process modeling, Model-based design, Optical lithography, Optical proximity correction, Critical dimension metrology, 193nm lithography, Lithography, Tolerancing, Modeling

Read Abstract +

With 193nm optical lithography being extended to 12nm design rules and beyond, quality and performance requirements for photomasks are becoming increasingly challenged to support the increased pattern complexity. Additionally, interactions between mask, the lithography process, and OPC (Optical Proximity Correction) are becoming a more critical tool in tolerance reduction. One of the tools being used to reduce this variation is Mask Process Correction (MPC). Model-based Mask Process Correction (MB-MPC) is one of the key tools used to improve photomask Critical Dimension (CD) uniformity and provide high fidelity, and increase patterning stability of resolution limited features, such as assist features (SRAFs) at today’s leading-edge nodes. Since 2017, participants in the eBeam Initiative Mask Maker Survey have reported that MPC is considered a requirement for 16nm and below. Reduction of systematic photomask CD errors with MPC enables improvement of the accuracy of Optical Proximity Correction models by reducing mismatch between actual and modelled masks. While model-based MPC has been demonstrated to reduce mask fidelity and dimensional errors to sub 1nm on mask, one of the downsides is that it is a slow and resource intensive solution. An advanced model based MPC requires massive numbers of CPUs and their associated EDA licenses. In this paper, we will teach a technique for mitigation by use of a Rule-Based MPC (RB-MPC) solution with MB-MPC accuracy to reduce Mask Data Prep (MDP) runtime with no loss in patterning quality. We report on a full cycle of model to rule-based MPC simplification approaches and verification. We will describe the process by which we have been able to migrate a model-based MPC (MB-MPC) solution to a more cost effective, and equally accurate Rule-based MPC (RB-MPC) solution. This will included the methodology for derivation, implementation, and verification of the modified RB-MPC, which is based on both mask, and wafer performance metrics, and characterization of limitations of this process, as the challenges in converting to a RB-MPC from a MBMPC solution by application, including technology, mask process, target layer, and wafer-performance metrics.

Proceedings Article | 3 October 2018 Paper

Paper

Applying MPC for EUV mask fabrication

Dai Tsunoda, Yohei Torigoe, Yutaro Sato, Masakazu Hamaji, Gek-Soon Chua, Christian Bürgel

Proceedings Volume 10810, 108101H (2018) https://doi.org/10.1117/12.2502068

KEYWORDS: Photomasks, Extreme ultraviolet, Etching, Calibration, Extreme ultraviolet lithography, Critical dimension metrology, Mask making

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Proceedings Article | 8 October 2014 Paper

Paper

Mask model calibration for MPC applications utilizing shot dose assignment

Ingo Bork, Peter Buck, Sankaranarayanan Paninjath, Kushlendra Mishra, Christian Bürgel, Keith Standiford, Gek Soon Chua

Proceedings Volume 9235, 92350A (2014) https://doi.org/10.1117/12.2069617

KEYWORDS: Calibration, Critical dimension metrology, Scanning electron microscopy, Cadmium, Etching, Error analysis, Visualization, Photomasks, Vestigial sideband modulation, Statistical modeling

Read Abstract +

Shrinking feature sizes and the need for tighter CD (Critical Dimension) control require the introduction of new technologies in mask making processes. One of those methods is the dose assignment of individual shots on VSB (Variable Shaped Beam) mask writers to compensate CD non-linearity effects and improve dose edge slope. Using increased dose levels only for most critical features, generally only for the smallest CDs on a mask, the change in mask write time is minimal while the increase in image quality can be significant. However, this technology requires accurate modeling of the mask effects, especially the CD/dose dependencies. This paper describes a mask model calibration flow for Mask Process Correction (MPC) applications with shot dose assignment. The first step in the calibration flow is the selection of appropriate test structures. For this work, a combination of linespace patterns as well as a series of contact patterns are used for calibration. Features sizes vary from 34 nm up to several micrometers in order to capture a wide range of CDs and pattern densities. After mask measurements are completed the results are carefully analyzed and measurements very close to the process window limitation and outliers are removed from the data set. One key finding in this study is that by including patterns exposed at various dose levels the simulated contours of the calibrated model very well match the SEM contours even if the calibration was based entirely on gauge based CD values. In the calibration example shown in this paper, only 1D line and space measurements as well as 1D contact measurements are used for calibration. However, those measurements include patterns exposed at dose levels between 75% and 150% of the nominal dose. The best model achieved in this study uses 2 e-beam kernels and 4 kernels for the simulation of development and etch effects. The model error RMS on a large range of CD down to 34 nm line CD is 0.71 nm. The calibrated model is then used to generate 2D contours for line ends, space ends and contacts and those contours are compared to SEM images. For all patterns, including those very close to the resolution limit, very good contour overlay is achieved. It appears that by including the various dose levels in the calibration a very good separation of the e-beam model components from the etch components is possible and that this also results in very accurate 2D model quality. In conclusion, very accurate mask model calibration is achieved for mask processes using shot dose assignment. Standard test patterns can be used for calibration if they include the dose variations intended for correction.

Proceedings Article | 8 October 2014 Paper

Paper

Model-based virtual VSB mask writer verification for efficient mask error checking and optimization prior to MDP

Robert Pack, Keith Standiford, Todd Lukanc, Guo Xiang Ning, Piyush Verma, Fadi Batarseh, Gek Soon Chua, Akira Fujimura, Linyong Pang

Proceedings Volume 9235, 923509 (2014) https://doi.org/10.1117/12.2069613

KEYWORDS: Photomasks, Optical proximity correction, Lithography, Vestigial sideband modulation, Semiconducting wafers, Data modeling, Model-based design, Error analysis, Manufacturing, Critical dimension metrology

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Proceedings Article | 18 March 2014 Paper

Paper

EUV OPC modeling and correction requirements

Tamer Coskun, Tom Wallow, Gek Soon Chua, Keith Standiford, Craig Higgins, Yi Zou

Proceedings Volume 9048, 90480W (2014) https://doi.org/10.1117/12.2046341

KEYWORDS: Photomasks, 3D modeling, Optical proximity correction, Data modeling, Extreme ultraviolet, Calibration, Semiconducting wafers, Critical dimension metrology, Extreme ultraviolet lithography, Data processing

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Proceedings Article | 9 September 2013 Paper

Paper

Entering mask process correction era for EUV mask manufacturing

Christian Bürgel, Keith Standiford, Gek Soon Chua

Proceedings Volume 8880, 888008 (2013) https://doi.org/10.1117/12.2023093

KEYWORDS: Data modeling, Photomasks, Etching, Error analysis, Critical dimension metrology, Inspection, Calibration, Extreme ultraviolet, Statistical modeling, Electronic design automation

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Proceedings Article | 12 April 2013 Paper

Paper

Introducing a novel flow to estimate challenges encountered while transitioning from RET development to manufacturable solution

Jacky Cheng, Robin Chia, Ying Gong, Omar ElSewefy, GekSoon Chua, YeeMei Foong, Aasutosh Dave, Alvin Chua, DongQing Zhang, Vlad Liubich, Pat Lacour, Alex Tritchkov

Proceedings Volume 8683, 86830K (2013) https://doi.org/10.1117/12.2013605

KEYWORDS: Resolution enhancement technologies, Optical proximity correction, Source mask optimization, SRAF, Photomasks, Optimization (mathematics), Manufacturing, Tolerancing, Semiconducting wafers, Double patterning technology

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Proceedings Article | 1 April 2013 Paper

Paper

Evaluation of methods to improve EUV OPC model accuracy

Tamer Coskun, Chris Clifford, Germain Fenger, Gek Soon Chua, Keith Standiford, Ralph Schlief, Craig Higgins, Yi Zou

Proceedings Volume 8679, 86790V (2013) https://doi.org/10.1117/12.2009281

KEYWORDS: Optical proximity correction, Photomasks, Extreme ultraviolet, Calibration, Extreme ultraviolet lithography, Deep ultraviolet, Lithography, Metrology, Data modeling, Semiconducting wafers

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Proceedings Article | 8 November 2012 Paper

Paper

Choosing the data flow paradigm for EUV mask process corrections

Christian Bürgel, Keith Standiford, Gek Chua

Proceedings Volume 8522, 85220Y (2012) https://doi.org/10.1117/12.965225

KEYWORDS: Photomasks, Optical proximity correction, Data modeling, Calibration, Data conversion, Point spread functions, Manufacturing, Extreme ultraviolet, Process modeling, Semiconducting wafers

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Proceedings Article | 30 June 2012 Paper

Paper

Systematic study of source mask optimization and verification flows

Yu Ben, Azat Latypov, Gek Soon Chua, Yi Zou

Proceedings Volume 8441, 84410U (2012) https://doi.org/10.1117/12.965565

KEYWORDS: Source mask optimization, Molybdenum, Optical proximity correction, Electroluminescence, Resolution enhancement technologies, Tolerancing, Critical dimension metrology, Semiconducting wafers, Data modeling, Calibration

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Proceedings Article | 13 March 2012 Paper

Paper

Source mask optimization methodology (SMO) and application to real full chip optical proximity correction

DongQing Zhang, GekSoon Chua, YeeMei Foong, Yi Zou, Stephen Hsu, Stanislas Baron, Mu Feng, Hua-Yu Liu, Zhipan Li, Jessy Schramm, T. Yun, Carl Babcock, Byoung IL Choi, Stefan Roling, Alessandra Navarra, Tanja Fischer, Andre Leschok, Xiaofeng Liu, Weijie Shi, Jianhong Qiu, Russell Dover

Proceedings Volume 8326, 83261V (2012) https://doi.org/10.1117/12.916614

KEYWORDS: Source mask optimization, Optical proximity correction, Semiconducting wafers, Lithography, Electroluminescence, Scanning electron microscopy, Finite element methods, Etching, Critical dimension metrology, Image processing

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Proceedings Article | 14 October 2011 Paper

Paper

Optimization of mask shot count using MB-MDP and lithography simulation

Gek Soon Chua, Wei Long Wang, Byoung IL Choi, Yi Zou, Cyrus Tabery, Ingo Bork, Tam Nguyen, Aki Fujimura

Proceedings Volume 8166, 816632 (2011) https://doi.org/10.1117/12.897037

KEYWORDS: Photomasks, Optical proximity correction, Lithography, Photovoltaics, Data modeling, Semiconducting wafers, SRAF, Source mask optimization, Vestigial sideband modulation, Model-based design

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Proceedings Article | 2 April 2010 Paper

Paper

Preliminary results for photomask haze mitigation in a fab environment

Thomas Ku, Jeff LeClaire, Sia Kim Tan, Gek Soon Chua, Ron Bozak, Roy White, Tod Robinson, Michael Archuletta, David Lee

Proceedings Volume 7638, 763817 (2010) https://doi.org/10.1117/12.848283

KEYWORDS: Photomasks, Air contamination, Semiconducting wafers, Reticles, Inspection, Pellicles, Contamination, Manufacturing, Deep ultraviolet, Critical dimension metrology

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Proceedings Article | 4 March 2010 Paper

Paper

Radial segmentation approach for contact hole patterning in 193 nm immersion lithography

Moh Lung Ling, Gek Soon Chua, Sia Kim Tan, Cho Jui Tay, Chenggen Quan, Qunying Lin

Proceedings Volume 7640, 76402M (2010) https://doi.org/10.1117/12.848431

KEYWORDS: Optical lithography, Nanoimprint lithography, Image segmentation, Optical proximity correction, Photomasks, Immersion lithography, Image enhancement, Printing, Diffraction, SRAF

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Proceedings Article | 4 March 2010 Paper

Paper

Intra field CD uniformity correction by Scanner Dose MapperTM using Galileo® mask transmission mapping as the CDU data source

Gek Soon Chua, Chason Eran, Sia Kim Tan, Byoung IL Choi, Teng Hwee Ng, Poh Ling Lua, Ofir Sharoni, Guy Ben-Zvi

Proceedings Volume 7640, 76402U (2010) https://doi.org/10.1117/12.852819

KEYWORDS: Scanners, Semiconducting wafers, Reticles, Critical dimension metrology, Photomasks, Databases, Calibration, Associative arrays, Data conversion, Printing

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Proceedings Article | 16 March 2009 Paper

Paper

Line end shortening and corner rounding for novel off-axis illumination source shapes

Moh Lung Ling, Gek Soon Chua, Qunying Lin, Cho Jui Tay, Chenggen Quan

Proceedings Volume 7274, 72742V (2009) https://doi.org/10.1117/12.814057

KEYWORDS: Optical proximity correction, Diffusion, Image quality, Lithography, Distortion, Critical dimension metrology, Diffraction, Spatial frequencies, Illumination engineering, Lithographic illumination

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Proceedings Article | 12 March 2008 Paper

Paper

Customized illumination shapes for 193nm immersion lithography

Moh Lung Ling, Gek Soon Chua, Qunying Lin, Cho Jui Tay, Chenggen Quan

Proceedings Volume 6924, 692435 (2008) https://doi.org/10.1117/12.772441

KEYWORDS: Critical dimension metrology, Lithographic illumination, Diffraction, Photomasks, Optical lithography, Immersion lithography, Resolution enhancement technologies, Coherence imaging, Phase shifts, Spatial frequencies

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Proceedings Article | 25 October 2007 Paper

Paper

Progressive growth and hard defect disposition integrated system for 65nm and 45nm ArF immersion lithography

Gek Soon Chua, Sia Kim Tan, Byoung Il Choi, Oi Yin Lee, Jeong Soo Kim

Proceedings Volume 6730, 673027 (2007) https://doi.org/10.1117/12.746622

KEYWORDS: Photomasks, Air contamination, Semiconducting wafers, Inspection, Critical dimension metrology, Lithography, Opacity, System integration, Immersion lithography, Scanners

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Proceedings Article | 26 March 2007 Paper

Paper

A comparative study for mask defect tolerance on phase and transmission for dry and immersion 193-nm lithography

Moh Lung Ling, Gek Soon Chua, Cho Jui Tay, Chenggen Quan, Qunying Lin

Proceedings Volume 6520, 65203U (2007) https://doi.org/10.1117/12.711629

KEYWORDS: Air contamination, Photomasks, Immersion lithography, Critical dimension metrology, Lithography, Tolerancing, Phase shifts, Lithographic illumination, Imaging systems, Reticles

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Proceedings Article | 12 May 2005 Paper

Paper

Polarization impact on partially coherent imaging

Gek Soon Chua, Cho Jui Tay, Chenggen Quan, Qunying Lin

Proceedings Volume 5754, (2005) https://doi.org/10.1117/12.600415

KEYWORDS: Polarization, Photomasks, Lithographic illumination, Phase shifts, Optical lithography, Immersion lithography, Image quality, Coherence (optics), System on a chip, Image acquisition

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Proceedings Article | 28 May 2004 Paper

Paper

Rigorous diffraction analysis using geometrical theory of diffraction for future mask technology

Gek Chua, Cho Tay, Chenggen Quan, Qunying Lin

Proceedings Volume 5377, (2004) https://doi.org/10.1117/12.536160

KEYWORDS: Diffraction, Photomasks, Etching, Phase shifts, Quartz, Isotropic etching, Lithography, Optical proximity correction, Optical lithography, Wet etching

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Proceedings Article | 26 June 2003 Paper

Paper

Dipole options for 90-nm lithography technologies and below

Gek Chua, Cho Tay, Chenggen Quan, Qunying Lin, Leng-Hai Chua

Proceedings Volume 5040, (2003) https://doi.org/10.1117/12.485432

KEYWORDS: Scattering, Lithography, Diffraction, Sodium, Lithographic illumination, Photomasks, Optical lithography, Resolution enhancement technologies, Objectives, Single sideband modulation

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Proceedings Article | 30 July 2002 Paper

Paper

Sub-0.10-um lithography technology with resolution enhancement technique

Gek Chua, Qunying Lin, Cho Tay, Chenggen Quan

Proceedings Volume 4691, (2002) https://doi.org/10.1117/12.474544

KEYWORDS: Scattering, Optical proximity correction, Lithography, Photomasks, Resolution enhancement technologies, Optical lithography, Critical dimension metrology, Phase shifts, Lithographic illumination, Electroluminescence

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Proceedings Article | 30 July 2002 Paper

Paper

MEF studies for attenuated phase-shift mask for sub-0.13-um technology using 248 nm

Sia-Kim Tan, Qunying Lin, Gek Chua, Chenggen Quan, Cho Tay

Proceedings Volume 4691, (2002) https://doi.org/10.1117/12.474520

KEYWORDS: Photomasks, Atrial fibrillation, Optical lithography, Critical dimension metrology, Semiconducting wafers, Lithography, Resolution enhancement technologies, Optical proximity correction, Reticles, Semiconductor manufacturing

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Showing 5 of 25 publications

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