• [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).

• 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

1. [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). 

2. [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). 

3. [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).

4. [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).

5. [TCAD] W. Lee et al, "Method of three-dimensional optoelectrical simulation of image sensor," US Patent 10,318,678 (2019). 

6. [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).

7. [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).

8. [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).

9. [Optics] W. Lee and F. L. Degertekin, “Rigorous coupled-wave analysis of multilayered grating structures,” IEEE Journal of Lightwave Technology (2004). 

10. [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).

11. [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).