Wook Lee
I have been working on development of CMOS image sensor pixel based on TCAD simulation for long, at Samsung Electronics. Before this, I got a Ph.D. degree from Georgia Institute of Technology, Atlanta in 2006, in the are of optical MEMS (mciro-electro-mechanical system).
During 2019-2020, I was also a visiting researcher at Delft University of Technology in the Netherlands, working with prof. Frans A. Oliehoek. My research topic was application of Reinforcement Learning for autonmous design of semiconductor devices. I developed a sample-efficient, generalizable RL algorithm for optimization and evaluated it with analog circuit design.
I have a strong background on image sensors, optics, TCAD simulation, MEMS and keen interest in learning-based design automation and optimization. Love to challenge interdisciplinary problems and learn something out of them. Feel free to get in touch with me :)
Contact: wleegt at gmail dot com | Google Scholar
Research Updates
[Oct. 2023] Some update on patents for image sensors:
(1) one patent application was filed in June (US application # 18/331,343), which is about improved fabrication method and design for self-aligned dual-VTG (vertical transfer gate) in miniaturized pixels. (2) another one, which covers proposed methods to boost quantum efficiency based on various grating structures, was finally issued in May (US patent # 11,658,194).
[Sep. 2022] "Simulation-based Study on Characteristics of Dual Vertical Transfer Gates in Sub-micron Pixels for CMOS Image Sensors" presented in International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) 2022. Link
[Nov. 2020] "Analog circuit design with Dyna-style reinforcement learning" presented in Workshop on Machine Learning for Engineering Modeling, Simulation and Design @ NeurIPS 2020. Link
Education
Ph.D. in Electrical and Computer Engineering, Georgia Institute of Technology (2001-2006)
- Keywords: sensors & microsystems, diffraction analysis, CMOS readout chip design | advisor: prof. F. Levent Degertekin
- Thesis: diffraction-based integrated optical readout for micromachined optomechanical sensors Link
M.S. in Electrical Engineering, Pennsylvania State University (1999-2001)
- Keywords: optics | advisor: prof. Ruyan Guo
- Thesis: theoretical and experimental studies on Gaussian beam propagation in uniaxial crystals
B.S. in Electrical Engineering, Seoul National University (1991-1995)
Professional Experiences
Principal Engineer at Semiconductor R&D Center, Samsung Electronics Co., Korea (2006-present)
- Keywords: image sensor pixel design, optics, TCAD simulation, DTCO
Visiting Researcher at TU Delft, the Netherlands (2019-2021)
- Keywords: reinforcement learning based optimizaiton, analog circuit design automation
Research Engineer at Advanced Display & MEMS Research Center (1997-1999)
- Keywords: uncooled IR image sensor (aka microbolometer) developement
Selected Publications & Patents
[Image Sensor] D. Kim, K. Cho, H. Ji, M. Kim, J. Kim, T. Kim, S. Seo, D. Im, Y. Lee, J. Choi, S. Yoon, I. Noh, J. Kim, K. Lee, H. Jung, J. Shin, H. Hur, K. Chang, I. Cho, K. Woo, B. Moon, J. Kim, Y. Ahn, D. Sim, S. Park, W. Lee et al, “A 1/1.56-inch 50MPixel CMOS Image Sensor with 0.5um pitch Quad Photodiode Separated by Front Deep Trench Isolation,” In International Solid-State Circuits Conference (2024).
[Image Sensor] W. Lee et al, "Image sensors having grating structures therein that provide enhanced diffraction of incident light," US Patent 11,658,194 (2023).
[Image Sensor] W. Lee et al, "Simulation-based Study on Characteristics of Dual Vertical Transfer Gates in Sub-micron Pixels for CMOS Image Sensors," International Conference on Simulation of Semiconductor Processes and Devices (2022).
[Machine Learning] W. Lee and F. A. Oliehoek, "Analog circuit design with Dyna-style reinforcement learning," NeurIPS 2020 Workshop on Machine Learning for Engineering Modeling, Simulation and Design (2020).
[TCAD] W. Lee et al, "Method of three-dimensional optoelectrical simulation of image sensor," US Patent 10,318,678 (2019).
[Image Sensor] J. Ahn, C. Moon, B. Kim, K. Lee, Y. Kim, M. Lim, W. Lee et al, “Advanced image sensor technology for pixel scaling down toward 1.0μm,” IEEE International Electron Devices Meeting (2008).
[MEMS] A. G. Onaran, M. Balantekin, W. Lee et al, “A new atomic force microscope probe (AFM) with force sensing integrated readout and active tip (FIRAT),” Review of Scientific Instruments (2006).
[MEMS] W. Lee, N. A. Hall, and F. L. Degertekin, “A grating-assisted resonant-cavity-enhanced (GARCE) optical displacement detection method for micromachined sensors,” Applied Physics Letters (2004).
[Optics] W. Lee and F. L. Degertekin, “Rigorous coupled-wave analysis of multilayered grating structures,” IEEE Journal of Lightwave Technology (2004).
[MEMS] W. Lee, N. A. Hall, Z. Zhou, and F. L. Degertekin, “Fabrication and characterization of a micromachined acoustic sensor with integrated optical readout,” IEEE Journal of Selected Topics in Quantum Electronics (2004).
[MEMS] H. Lee, J. Yoon, E. Yoon, S. Ju, Y. Yong, W. Lee et al, “A high fill-factor infrared bolometer using micromachined multilevel electrothermal structures,” IEEE Transactions on Electron Devices (1999).