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84 results on '"Wu, Wengang"'

7. Monolithic Integration of GaN-Based Enhancement/Depletion-Mode MIS-HEMTs With AlN/SiN Bilayer Dielectric.

Author

Zhang, Bin, Wang, Jinyan, Wang, Chen, Wang, Xin, Huang, Chengyu, He, Jiayin, Wang, Maojun, Mo, Jianghui, Hu, Yansheng, and Wu, Wengang

Subjects
ATOMIC layer deposition, DIELECTRIC devices, CHEMICAL vapor deposition, DIELECTRICS, MODULATION-doped field-effect transistors, ETCHING techniques
Abstract

In this letter, we demonstrate a GaN-based E/D-mode (Enhancement/Depletion-mode) inverter with PEALD-AlN (Plasma Enhanced Atomic Layer Deposition) and LPCVD-SiN (Low Pressure Chemical Vapor Deposition) as bilayer gate dielectric, where the E-mode GaN-MISHEMT is fabricated based on our proposed self-terminating gate recess etching technique. The combination of the two dielectrics makes the device exhibits high gate swing and low dielectric/III-V interface state densities. So that the fabricated inverter shows a large logic swing, high temperature stability and low hysteresis effect. [ABSTRACT FROM AUTHOR]

Published
2022
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8. Improved Performance of Fully-Recessed High-Threshold-Voltage GaN MIS-HEMT With in Situ H₂/N₂ Plasma Pretreatment.

Author

Zhang, Bin, Wang, Jinyan, Wang, Xin, Wang, Chen, Huang, Chengyu, He, Jiayin, Wang, Maojun, Mo, Jianghui, Hu, Yansheng, and Wu, Wengang

Subjects
GALLIUM nitride, ATOMIC layer deposition, ELECTRON mobility, BREAKDOWN voltage
Abstract

In this letter, we demonstrate a high-threshold-voltage and high-current-density normally-off SiN/AlN/ GaN-on-Si MIS-HEMT with in situ low-damage H2/N2 plasma pretreatment. The in situ plasma pretreatment was performed in a plasma enhanced atomic layer deposition (PEALD) system prior to the PEALD-AlN deposition, which effectively suppress the interface trap densities between the AlN/GaN interface and increase the mobility of electrons to 198.80 cm $^{{2}}/\text {V} \cdot \text {s}$. Therefore, the devices demonstrate state-of-art characteristics with a competitive maximum drain current of 683.75 mA/mm at ${V} _{\textit {GS}} =15\text{V}$ and a high threshold of 6.28 V. The devices also show ON/OFF current ratio of $10^{{8}}$ and off-state breakdown voltage of 1778 V. [ABSTRACT FROM AUTHOR]

Published
2022
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27. 823-mA/mm Drain Current Density and 945-MW/cm2Baliga's Figure-of-Merit Enhancement-Mode GaN MISFETs With a Novel PEALD-AlN/LPCVD-Si3N4Dual-Gate Dielectric.

Author

Wang, Hongyue, Wang, Jinyan, Li, Mengjun, Cao, Qirui, Yu, Min, He, Yandong, and Wu, Wengang

Subjects
CURRENT density (Electromagnetism), MISFET (Transistors), DIELECTRICS
Abstract

In this letter, we demonstrate a novel PEALD-AlN/LPCVD-Si3N4dual-gate dielectric employed in enhancement-mode GaN MISFETs, where the gate recess is fabricated based on our proposed self-terminating gate recess etching technique using a GaN cap layer as recess mask. By using LPCVD-Si3N4and PEALD-AlN dual-gate dielectric layer, the devices exhibit a high-quality gate dielectric and a good GaN channel interface, yielding a high gate swing up to 18 V and a high channel effective mobility of 137 cm $^{\textsf {2}}/\textsf {V}\cdot \textsf {s}$ at such high gate bias. Thus, the fabricated devices feature a high maximum drain current density of 823mA/mm, a threshold voltage of 2.6 V, an on-resistance of $7.4~\Omega \cdot \textsf {mm}$ , and an ON/ OFF current ratio of 108with gate–drain distance of $2~\mu \text{m}$. Meanwhile, a high off-state breakdown voltage of 1290 V is achieved with 10- $\mu \text{m}$ gate–drain distance. The corresponding specific on-resistance is as low as 1.76 $\text{m}\Omega \cdot \textsf {cm}^{\textsf {2}}$ , leading to a high Baliga's figure of merit of 945 MW/cm2. [ABSTRACT FROM AUTHOR]

Published
2018
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30. Characteristics of submicron-footprint TiO2 based AlGaN/GaN MOSHEMT on SiC substrate

Author

Lin Shuxun, Wang Maojun, Meng Di, Cheng P. Wen, Wu Wengang, Hao Yilong, Wang Jinyan, Zhang Yaohui, and Kei May Lau

Subjects
Materials science, business.industry, Non-blocking I/O, Transistor, Gate dielectric, Wide-bandgap semiconductor, Cutoff frequency, law.invention, Footprint (electronics), law, Breakdown voltage, Optoelectronics, business, Power density
Abstract

AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOSHEMTs) with thick (>30 nm), high-κ (TiO2/NiO), submicron-footprint (0.4 μm) gate dielectric on SiC substrate are demonstrated, which are found to exhibit low gate leakage current (~ 1 nA/mm of gate periphery), high IMAX (1 A/mm), and high drain breakdown voltage (188 V). The derived current gain cutoff frequency is 30 GHz (from S-parameter measurements). The output power density is 6.6 W/mm, and the associated power-added-efficiency is 46% at 2.5 GHz frequency and 50 V drain bias. This high performance submicron-footprint MOSHEMT is highly promising for microwave power amplifier applications in communication and radar systems.

Published
2013

32. Schottky-MOS Hybrid Anode AlGaN/GaN Lateral Field-Effect Rectifier With Low Onset Voltage and Improved Breakdown Voltage.

Author

Gao, Jingnan, Wang, Maojun, Yin, Ruiyuan, Liu, Shaofei, Wen, Cheng P., Wang, Jinyan, Wu, Wengang, Hao, Yilong, Jin, Yufeng, and Shen, Bo

Subjects
ELECTRIC current rectifiers, BREAKDOWN voltage, METAL oxide semiconductors
Abstract

For devices with a 15 micron anode-to-cathode distance, nearly 1.5 times increase in the blocking (breakdown) voltage (from 692 to 1030 V) has been achieved by replacing the alloyed Ohmic contact at the anode electrode of the conventional MOS gated hybrid-anode lateral field-effect rectifier (CMLFER) with a low barrier Schottky contact. The new Schottky-MOS hybrid-anode lateral field-effect rectifier is found to offer comparable low onset voltage ( V{\textbf {ON}} of 0.68±0.13 versus 0.65±0.11 V for CMLFER) independent of the anode-to- cathode distance. The immunity of the punch through caused by drain induced barrier lowering effect is obtained through the low barrier Schottky contact in anode, which is believed to be responsible for the reduction in the leakage current, and the improvement of rectifier breakdown voltage. [ABSTRACT FROM AUTHOR]

Published
2017
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33. Gate-Recessed Normally-OFF GaN MOSHEMT With Improved Channel Mobility and Dynamic Performance Using AlN/Si3N4 as Passivation and Post Gate-Recess Channel Protection Layers.

Author

Liu, Shaofei, Wang, Maojun, Tao, Ming, Yin, Ruiyuan, Gao, Jingnan, Sun, Haozhe, Lin, Wei, Wen, Cheng P., Wang, Jinyan, Wu, Wengang, Hao, Yilong, Zhang, Zhaofu, Chen, Kevin J., and Shen, Bo

Subjects
INTEGRATED circuit passivation, VOLTAGE control, ELECTRICAL properties of electron gas
Abstract

In this letter, a gate recessed normally-off GaN metal–oxide–semiconductor high-electron-mobility transistor on silicon substrate is fabricated using AlN/Si3N4 as the passivation layer. The thin AlN layer serves the dual role of protecting the gate channel region from direct plasma bombardment during the RIE Si3N4 removal and passivating the surface states in the access region. As a result, the effective carrier mobility in the normally-off channel is found to improve from the 568 cm2/ \text V\cdot \text s in conventional Si3N4 passivation process to a high value of 1154 cm2/ \text V\cdot \text s . A saturated output current density of 603 mA/mm and an ON-resistance of 5.3~\Omega \cdot \text mm was obtained for devices with \textL\text {G}/\textL\text {GS}/\textL\text {GD}/\text{W}\text {G} = 1.5 /1.5/3/ 20~\mu \textm . Meanwhile, the degradation of dynamic ON-resistance is significantly suppressed due to the effective passivation of surface states by the AlN layer grown by plasma-enhanced atomic layer deposition. [ABSTRACT FROM AUTHOR]

Published
2017
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34. Buffer-Induced Time-Dependent OFF-State Leakage in AlGaN/GaN High Electron Mobility Transistors on Silicon.

Author

Tao, Ming, Wang, Maojun, Liu, Shaofei, Xie, Bing, Yu, Min, Wen, Cheng P., Wang, Jinyan, Hao, Yilong, Wu, Wengang, and Shen, Bo

Subjects
MODULATION-doped field-effect transistors, STRAY current measurement, SILICON analysis, THRESHOLD voltage, ALUMINUM gallium nitride, GALLIUM nitride, WIDE gap semiconductors, BUFFER layers
Abstract

Time-dependent OFF-state leakage behavior of AlGaN/GaN MISHEMTs on silicon substrate is investigated and a novel degradation mechanism is proposed in this paper. Under constant high voltage OFF-state stress, drain leakage current gradually increases with stress time and the behavior is gate bias and temperature-dependent. Consecutive OFF-state breakdown measurement with drain injection technique indicates that the negative shift of threshold voltage ( V\mathrm {th} ) is responsible for the increase of drain leakage current during stress measurement. It is proposed that the negative shift of V\mathrm {th} is mainly induced by the ionization of uncompensated donor like deep levels near the channel, which are most likely to be located in the 300-nm-thick unintentionally doped GaN layer above the carbon doped buffer layer. [ABSTRACT FROM PUBLISHER]

Published
2016
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45. A GaN HEMT Structure Allowing Self-Terminated, Plasma-Free Etching for High-Uniformity, High-Mobility Enhancement-Mode Devices.

Author

Lin, Shuxun, Wang, Maojun, Sang, Fei, Tao, Ming, Wen, Cheng P., Xie, Bing, Yu, Min, Wang, Jinyan, Hao, Yilong, Wu, Wengang, Xu, Jun, Cheng, Kai, and Shen, Bo

Subjects
GALLIUM nitride, MODULATION-doped field-effect transistors, WIDE gap semiconductors, NANOFABRICATION, LOGIC circuits, ELECTRON mobility, QUANTUM wells
Abstract

In this letter, a plasma-free etch stop structure is developed for GaN HEMT toward enhancement-mode operation. The self-terminated precision gate recess is realized by inserting a thin AlN/GaN bilayer in the AlGaN barrier layer. The gate recess is stopped automatically at the GaN insertion layer after high-temperature oxidation and wet etch, leaving a thin AlGaN barrier to maintain a quantum well channel that is normally pinched off. With addition of an Al2O3 gate dielectric, quasi normally OFF GaN MOSHEMTs have been fabricated with high threshold uniformity and low ON-resistance comparable with the normally ON devices on the same wafer. A high channel mobility of 1400 cm ^2/\textrm V\cdot \textrm s was obtained due to the preservation of the high electron mobility in the quantum-well channel under the gate. [ABSTRACT FROM AUTHOR]

Published
2016
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