[March 2025] Jointly appointed as adjunct professor at Sungkwunkwan University for industry-university collaobration. Thank both Samsung & SKKU for this new journey.
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. I developed a sample-efficient, generalizable RL algorithm for optimization and evaluated it with analog circuit design.
Strong background on sensor and semiconductor device, optics, TCAD, MEMS and recently keen interest in ML for optimization, DTCO. Love to challenge interdisciplinary problems and learn something new. Feel free to get in touch with me :)
Contact: wleegt at gmail dot com | Google Scholar
[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
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)
Collaboration Professor at Dept. of Semiconductor Convergence Eng., Sungkyunkwan University , Korea (2025-)
- Keywords: ML for optimzation, DTCO
Principal Engineer at Semiconductor R&D Center, Samsung Electronics Co., Korea (2006-2025)
- Keywords: image sensor pixel design, optics, TCAD simulation
Visiting Researcher at TU Delft, Netherlands (2019-2021)
- Keywords: reinforcement learning based optimizaiton, analog circuit design automation
Research Engineer at Advanced Display & MEMS Research Center, Korea (1997-1999)
- Keywords: uncooled IR image sensor (aka microbolometer) developement
[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).