Join us in celebrating a significant academic milestone achieved by Jing Feng Leong, Hank (Chun-Kuei Chen), and Zefeng Xu, on successfully passing their PhD oral defense! Their dedication and hard work have led them to this remarkable achievement, with continuous contributions to their respective fields in 2D materials, Oxide semiconductors, and photonics technology! Cheers!
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Dec 2023: We are thrilled to announce that our paper, titled “Negative-U Defect Passivation in Oxide-Semiconductor by Channel Defect Self-Compensation Effect to Achieve Low Bias Stress VTH Instability of Low-Thermal Budget IGZO TFT and FeFETs,” authored by Hank Chun-Kuei Chen and Xu Zefeng, has been accepted and presented at the 69th International Electron Device Meeting (IEDM) held in San Francisco, CA in December 2023.
In this paper, we elucidate the fundamental bias stress reliability mechanism in oxide-semiconductor transistors and provide guidelines to improve interface/bulk-induced VTH degradation. Specifically, how our ITO-IGZO approach led to effective interface/channel defect-self compensation effect to passivate defects such as negative-U defects, and ionized-oxygen-vacancy defects. With the bilayer ITO-IGZO channel, we demonstrated 10x negative/positive bias stress (NBS/PBS) VTH shift improvement. Our reliability-optimized dual-mode memory-logic DG ITO-IGZO FeFETs set a new oxide-based transistor reliability record making major strides toward highly reliable BEOL logic and memory switches.
Dec 2023: We are delighted to announce that our paper, titled “First Demonstration of HZO-LNOI Integrated Ferroelectric Electro-Optic Modulator and Memory to Enable Reconfigurable Photonic Systems,” authored by Xu Zefeng and Hank Chun-Kuei Chen, has been accepted and presented at the 69th International Electron Device Meeting (IEDM) held in San Francisco, CA in December 2023. The paper introduces an innovative concept by integrating a ferroelectric capacitor, based on the ferroelectric material HZO, with a lithium niobate on insulator micro ring resonator (LNOI MRR). This integration results in a non-volatile resonance shift, functioning as a multi-state photonic memory. Additionally, leveraging this unique photonic memory, we propose a chiplet-interposer interconnect system, enabling dynamic channel selection for more efficient communication between chiplets.
June 2023: Jieming Pan has been selected for the prestigious Eric and Wendy Schmidt AI in Science Postdoctoral Fellowship. This program supports outstanding individuals applying AI methods to their research, with approximately 160 postdoctoral fellows participating from various universities. The fellowship, founded by Eric and Wendy Schmidt through their philanthropic initiative Schmidt Futures, aims to bring talented individuals together to solve challenging problems in science and society.
June 2023: We are thrilled to announce that our research on low-thermal budget oxide-based FETs has been accepted for presentation at the prestigious VLSI Symposium (https://www.vlsisymposium.org/). Our breakthrough findings in this field have yielded remarkable results, setting new records and showcasing unparalleled performance.
Through our research, we have successfully demonstrated oxide-based FETs with exceptional characteristics, including a record ID, Max of 790 µA/µm at VDS=1V, enhancement-mode operation (VTH>0), a Subthreshold Swing (S.S.) of less than 90 mV/dec., and Drain-Induced Barrier Lowering (DIBL) of approximately 20mV/V at an ultra-scaled channel length (LCH) of 50 nm. These groundbreaking achievements have been made possible through the utilization of an optimized InSnOx-InGaZnOx (ITO-IGZO) hetero-junction channel, enabling channel defect self-compensation.
Our innovative approach overcomes the inherent challenges faced by n-type oxide FETs, such as negative threshold voltage (VTH) caused by donor-type channel oxygen vacancy (Vo) and limited tunability of gate metal work function. By implementing the ITO-IGZO channel and defect self-compensation technique, we have significantly enhanced the transistor’s effective mobility (μeff) to an impressive 110 cm2/V·s, while scaling down the channel thickness to 4 nm. It is noteworthy that this unique channel thickness independent mobility behavior has not been observed in IGZO or ITO mono-channel FETs.
Our research establishes a new benchmark for oxide-based FETs, showcasing best-in-class mobility that is comparable to unstrained Silicon thin film and SOI FETs. Furthermore, our FETs are compatible with sub-400°C back-end-of-line (BEOL) processes, adding to their versatility and practical applicability.
Oct 2022: Aaron Thean will be contributing as one of the distinguished speakers at IBM IEEE CAS/EDS – AI Compute Symposium at IBM Yorktown Heights, New York 12 -13 October 2022 (https://www.zurich.ibm.com/thinklab/AIcomputesymposium.html)
Dec 2022: Hank Chun-Kuei Chen will be presenting paper “First Demonstration of Ultra-low Dit Top-Gated Ferroelectric Oxide-Semiconductor Memtransistor with Record Performance by Channel Defect Self-Compensation Effect for BEOL-Compatible Non-Volatile Logic Switch” at the coming 68th International Electron Device Meeting (IEDM) in San Francisco, CA in Dec 2022. https://www.ieee-iedm.org. The team that contributed to the work includes: Zihang Fang, Sonu Hooda, Manohar Lal, Umesh Chand, Zefeng Xu, Jieming Pan, Shih-Hao Tsai, Evgeny Zamburg.
Dec 2022: Aaron Thean will be presenting invited paper “Low-Thermal-Budget BEOL-Compatible Beyond-Silicon Transistor Technologies for Future Monolithic-3D Compute and Memory Applications” at the coming 68th International Electron Device Meeting (IEDM) in San Francisco, CA in Dec 2022. https://www.ieee-iedm.org.