A5056707965- Semiconductor materials and devices
- Ferroelectric and Negative Capacitance Devices
- ZnO doping and properties
- Thin-Film Transistor Technologies
- MXene and MAX Phase Materials
- GaN-based semiconductor devices and materials
- Ga2O3 and related materials
- Advanced Memory and Neural Computing
- Nanowire Synthesis and Applications
- Ferroelectric and Piezoelectric Materials
- Electrocatalysts for Energy Conversion
- Semiconductor Quantum Structures and Devices
- Metal and Thin Film Mechanics
- Acoustic Wave Resonator Technologies
- Advanced Sensor and Energy Harvesting Materials
- Silicon Carbide Semiconductor Technologies
- Machine Learning in Materials Science
- Magnetic and transport properties of perovskites and related materials
- Electronic Packaging and Soldering Technologies
- Gas Sensing Nanomaterials and Sensors
- Advancements in Semiconductor Devices and Circuit Design
- Electronic and Structural Properties of Oxides
The University of Tokyo
2024
National Yang Ming Chiao Tung University
2021-2024
Tokyo University of Information Sciences
2024
Hodges University
2023
The ferroelectric polarization stability and dielectric characteristics of ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -HfO superlattice (SL) layer Metal-Ferroelectric-Metal (MFM) capacitor fabricated with various post-metal annealing (PMA) temperatures were presented. It was demonstrated that SL MFM capacitors increased post metallization PMA temperature (i.e., 600 °C) showed improved almost <italic...
In this article, enhancement-mode thin-film transistors (TFTs) with atomic layer deposition (ALD)-derived ultrathin (≈3 nm) amorphous indium–zinc oxide (a-IZO) channel were demonstrated. Our devices showed improved device characteristics as benchmarked thicker IZO channels. The ALD-deposited TFT an In/Zn ratio of ≈6:4 exhibited a high field-effect mobility ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math...
In this letter, 5 nm-thick HZO ultra-thin ferroelectric capacitors with excellent remanent polarization (P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> ) and reliability are presented. The TiN/HZO/TiN metal-ferroelectric-metal (MFM) capacitor stack was deposited consecutively in the same atomic layer deposition (ALD) system without breaking vacuum (i.e. "in-situ" like) to improve interface quality between TiN electrodes layer. samples...
In this article, we have demonstrated the utilization of innovative atomic-layer-deposited (ALD) ultrathin ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 1.8 nm) amorphous InSnZnO notation="LaTeX">$\alpha$</tex-math> -ITZO) channel material in development a back-end-of-line (BEOL) compatible thin film transistor (TFT). Through optimization indium/tin/zinc (In/Sn/Zn)...
The high-performance atomic layer deposited (ALD) ultrathin (~2 nm) amorphous InZnO ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${a}$ </tex-math></inline-formula> -IZO, indium: Zinc ≈ 6:4) channel thin-film transistors (TFTs) with a short length notation="LaTeX">$\text{L}_{\mathbf {\textit {ch}}}$ ) of 50 nm were presented. Furthermore, the gate stability was evaluated using temperature-dependent...
E-mode hybrid ferroelectric charge storage gate (FEG) GaN HEMTs have shown promising performances for future power device applications. The FEG-HEMT demonstrates a combination of polarization and trapping process in the ferro-charge-storage stack, leading to positive threshold voltage shift operations. In this work, FEG-HEMTs with various Hf-based Zr-based layers are systematically studied. which employed nitrogen incorporated HfO2 (HfON) as layer shows an operation highest Vth (+2.3 V)...
In this work, we reported aggressively scaled amorphous InZnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> ($\alpha$-IZO) thin film transistor (TFT) in channel length (L xmlns:xlink="http://www.w3.org/1999/xlink">ch</inf> =8 nm) and thickness (2 as a promising candidate for monolithic three-dimensional (M3D) integrations at back-end-of-line (BEOL). The bottom gate TFT with ultra-short L of 8 nm exhibited excellent sub-threshold swings...
In this letter, the ferroelectric characteristics and reliability of TiN/Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub>/TiN Metal-Ferroelectric-Metal (MFM) capacitor fabricated using <i>‘‘in-situ’’</i> like consecutive atomic layer deposition (<i>C-ALD</i>) <i>“ex-situ”</i> techniques are compared for different post metal annealing (PMA) temperatures. We suggested that <i>C-ALD</i> improves interface HZO film higher PMA temperature...
In this work, we investigated the ferroelectric properties of Hf 0.5 Zr O 2 (HZO) Metal-Ferroelectric-Metal (MFM) capacitors on various refractory electrodes, including TiN, TaN, W, and Mo. By comparing different electrodes annealing temperature, found that MFM with TiN W showed both higher remanent polarization (2P r ) lower leakage current for post-metal (PMA) temperatures ranging from 400 °C to 600 °C. Moreover, capacitor electrode better saturated polarization-voltage (P-V) curve less...
Normally-off ferroelectric charge trap gate stack GaN high electron mobility transistor (FEG-HEMT) was fabricated with atomic layer etching (ALE) to precisely control the device parameters including <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text {V}_{\text {th}}$ </tex-math></inline-formula> of device. The ALE process consists cyclic Cl2 adsorption modification steps and Ar ion removal steps....
In this letter, HfO2/Al2O3/AlN hybrid stack capacitor with ferroelectric switching is experimentally demonstrated for the first time. The metal-insulator-semiconductor (MIS) capacitors and InGaZnO4 (IGZO) channel thin-film transistors (TFTs) gate are in letter. With stack, TFT exhibits clear counter-clockwise memory windows (MWs) of 6.5 V, 6.2 V 28.7 respectively measured at 368 K, RT, 80 K under sweep voltage ±40 V. Moreover, retention over <inline-formula...
A ferroelectric engineered charge trap gate E-mode GaN MIS-HEMT (FEG-HEMT), La-doped $\mathbf{H f}_{0.5} \text{Zr}_{0.5} \mathbf{O}_{2}$ (HZLO) with seed layer (SL), significantly reduced thermal budget $\left(\sim 200^{\circ} \text{C}\right)$, lowered leakage current, and 50% increase in $2P_{\text{r}}$, is implemented for the first time. The high-performance FEG-HEMT exhibits a positive $V_{\text {th}}$ of 3.7 V while maintaining I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML"...
This study focuses on the fabrication of high-performance thin-film transistors (TFTs) using an atomic layer deposited (ALD) ultra-thin (4 nm) amorphous <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{In}_{\mathrm{X}}\text{Zn}_{1-\mathrm{X}}\mathrm{O}$</tex> (IZO) channel. We investigated impact composition and annealing performance TFTs with...
In this study, we investigate the device characteristics and reliability of hybrid ferroelectric charge trap gate-stack enhancement-mode gallium nitride MIS-high electron mobility transistors (FEG-HEMTs) with various doping elements in trapping layer (CTL). FEG-HEMTs were fabricated fluorine-doped (F-HfO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text{2}}\text{)}$</tex-math> </inline-formula>...
The instability in polarization during the endurance test of Hf 0.5 Zr O 2 (HZO) ferroelectrics thin films including wake-up and fatigue are still major challenges for development HZO-based ferroelectric memories. In this work, we will review proposed mechanisms instabilities metal-ferroelectric-metal (MFM) capacitors. Then, material processing techniques to address issues provided. in-situ deposition electrode layers by atomic layer (ALD) attracted considerable attention as a promising...
In this study, the ferroelectric HfZrO2 (HZO) Metal-Ferroelectric-Metal (MFM) structures with various metal electrodes including TiN, W, Mo, TaN (i.e. MFM=TiN/HZO/TiN, W/HZO/W, Mo/HZO/Mo, TaN/HZO/TaN) were fabricated. We have characterized properties and microstructure of these MFM at annealing temperature. The orthorhombic phase samples different temperature investigated by grazing incidence x-ray diffraction (GIXRD). Microstructure analysis for capacitors also conducted using TEM. trends...
A 5-nm-thick HfO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> anti-fuse one-time programmable (OTP) memory achieving a record-high pulsed window (MW) of <tex xmlns:xlink="http://www.w3.org/1999/xlink">$2.1\times 10^{8}$</tex> at low read voltage (V xmlns:xlink="http://www.w3.org/1999/xlink">read</inf> ) 1 V have been proposed and demonstrated for the first time. Furthermore, OTP shows robust 25°C retention with an extremely stable MW...