Advanced Methods of Semiconductor Research Seminar – Friday 17th of July 2026
We cordially invite you to an extraordinary Advanced Methods of Semiconductor Research Seminar which will exceptionally take place on Friday 17th of July 2026 at 11:15 in room 321, building A-1, where there will be delivered a lecture entitled:
Ge Quantum Dots Technology for Low-power Si Photonics on SiN platforms
by Prof. Pei-Wen Li
from National Yang Ming Chiao Tung University in Taiwan
The lecture abstract and a short speaker biography are attached below.
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Lecture abstract:
Si photonic integrated circuits (PICs) not only fuels energy-efficient, high-performance computation but also unleashes innovative revolution of quantum photonics. The holy grail for Si PICs is to achieve seamless integration with CMOS electronics using robust Si processing technology, realizing on-chip optical interconnects for improving power consumption and latency as well as expanding the versatility and functionality for on-chip sensing. Germanium (Ge) is a great savior for active devices of Si PICs thanks to its high absorption coefficients and pseudo-direct bandgap properties. Both bottom Si-waveguided Ge lasers and photodiodes have been demonstrated on 2-D SOI platforms, however, Si waveguides (WGs) are unfortunately opaque in the visible band and suffer strong optical nonlinearity in the infrared band. Besides, high threshold for Ge lasing and large dark current of Ge photodetectors remain to be improved.
Starting with our exciting discovery of Ge spherical quantum dot (QD) formation via the peculiar and symbiotic interactions of Si, Ge and O interstitials, we have embarked on an exciting journey of vigorous exploration, creating unique configurations of self-organized Ge QDs/Si-containing layers. Our aim is to generate advanced Ge QD photonic active devices, while using standard, mainstream Si processing techniques. This talk summarizes our portfolio of innovative Ge QD configurations. With emphasis on both controllability and reproducibility, we have fabricated size-tunable, spherical Ge QDs that are placed at predetermined spatial locations within Si-containing layers (SiO2, Si3N4, and Si) using a coordinated combination of lithographic patterning and self-assembled growth. A significant fabrication advantage of our approach is the high-temperature thermal stability of Ge QDs that are formed by thermal oxidation of poly-SiGe at 900 oC, offering process flexibility in the waveguide-material choices and device designs. Our Ge QD configurations have allowed a myriad of integration possibilities including top-to-bottom evanescent-wave coupling structures for SiN-waveguided Ge-QD photodiodes, phototransistors, and Ge-QD light-emitters within Si3N4 integrated photonics platforms for compact, low-power applications.
Biography of Prof. Pei-Wen Li: (Senior Member, IEEE) received her Ph.D. degree in electrical engineering from Columbia University in New York City in 1994. Since 2015, she is a Professor in the Institute of Electronics at National Chiao Tung University (NCTU) (as National Yang Ming Chiao Tung University (NYCU) in 2021). Prior to joining NCTU in 2015, she was a Distinguished Professor, Chair of Electrical Engineering Department, and Director of Nano Science and Technology at National Central University. She was a Research Visiting Scholar at Caltech in 2011-2012. She worked with Vanguard International Semiconductor Corporation on DRAM technology integration in 1995-1996. Her research themes focus on experimental germanium nanostructures and devices, encompassing quantum-dot single-electron transistors, qubits, and photodetectors, making use of self-assembly nanostructures in silicon integration technology. She has published more than 300 technical journal and conference papers and holds 8 patents.
Dr. Li was the chair of IEEE Taipei Section. She is an IEEE EDS Distinguished Lecturer, chair of WiED, BoG member, and has served on the VLSI Technology, Education, WiED, and Meetings committees of IEEE Electron Devices Society. She has been an associate editor for the Journal of Electronic Materials since 2023, an editor of IEEE Journal of Electron Device Society since 2022, and an editorial board member of Applied Physics A, Springer since 2020. She is a senior member of the IEEE Electron Device Society and serves on various IEEE conference committees. She is the Micron Chair Professor since 2024 and recognized as Outstanding Engineering Professor Award (2025) from Chinese Institute of Engineers, NSTC Future Technology Award (2025), Outstanding Research Award from Ministry of Science and Technology, Taiwan (2025). In 2018-2024, her group has published 7 papers in the prestigious conferences of IEDM and VLSI Tech., including one invited talk in IEDM 2020 and one highlight paper in IEDM 2022.
