A5100427164- GaN-based semiconductor devices and materials
- Advanced MEMS and NEMS Technologies
- Semiconductor materials and devices
- Mechanical and Optical Resonators
- Ga2O3 and related materials
- Photonic and Optical Devices
- Acoustic Wave Resonator Technologies
- Advanced Fiber Optic Sensors
- Silicon Carbide Semiconductor Technologies
- Semiconductor materials and interfaces
- Semiconductor Quantum Structures and Devices
- Nanowire Synthesis and Applications
- Advanced Surface Polishing Techniques
- ZnO doping and properties
- Advancements in Semiconductor Devices and Circuit Design
- Radio Frequency Integrated Circuit Design
- Nanofabrication and Lithography Techniques
- Advanced Sensor and Energy Harvesting Materials
- Image Processing Techniques and Applications
- Semiconductor Lasers and Optical Devices
- Analytical Chemistry and Sensors
- Adhesion, Friction, and Surface Interactions
- Microwave Engineering and Waveguides
- Electronic Packaging and Soldering Technologies
- Gas Sensing Nanomaterials and Sensors
Peking University
2015-2024
Zhejiang University
2023
Stomatology Hospital
2023
Beijing Advanced Sciences and Innovation Center
2023
Peking University People's Hospital
2023
Institute of Microelectronics
2010-2021
Nanjing Normal University
2021
Yale University
2020
Harvard University
2020
Rockefeller University
2020
This letter reports a normally-OFF <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm Al}_{2}{\rm O}_{3}/{\rm GaN}$</tex></formula> gate-recessed MOSFET using low-damage digital recess technique featuring multiple cycles of plasma oxidation and wet oxide removal process. The etching process eliminates the damage induced by bombardment in conventional inductively coupled dry so that good surface...
In this paper, we report the device performance of a high-voltage normally off <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">${\rm Al}_{2}{\rm O}_{3}/{\rm GaN}$ </tex-math></inline-formula> MOSFET on Si substrate. Normally operation is obtained by multiple cycles O}_{2}$ plasma oxidation and wet oxide-removal gate recess process. The recessed GaN with 3 notation="TeX">$\mu{\rm m}$ gate-drain distance...
In this letter, we report a quasi-vertical GaN Schottky barrier diode (SBD) fabricated on hetero-epitaxial layer silicon with low dislocation density and high carrier mobility. The reduction of is realized by inserting thin Ga vacancies to promote the bending. 1.6 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> cm xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> drift thickness 4.5 μm. prototype SBD delivers on/off current ratio...
An active-passivation p-GaN gate HEMT (AP-HEMT), featuring an active passivation layer extending into the drain-side access region, is demonstrated on a commercial E-mode p-GaN/AlGaN/GaN heterostructure wafer. The (APL) electrically connected to gate, and thus can supply/release mobile holes through electrode. in APL effectively shields overlaying surface traps from depleting underlying 2DEG channel, results much improved dynamic <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML"...
The hot-electron-related reliability is an important issue for GaN power devices under harsh operation condition or environment. These high-energy electrons can scatter toward the device surface buffer layer, introducing newly generated traps/defects and resulting in degradation of dynamic ON-resistance (RON). This work investigates characteristics active-passivation p-GaN gate HEMTs (AP-HEMTs) after hot-electron stress (HES). Unlike dielectric passivation whose RON performance often...
In this letter, we investigated the behaviors of surface- and buffer-induced current collapse in AlGaN/GaN high-electron mobility transistors (HEMTs) using a soft-switched pulsed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">\(I-V\) </tex-math></inline-formula> measurement with different quiescent bias points. It is found that buffer-related have relationship gate drain biases ( <italic...
In this letter, a plasma-free etch stop structure is developed for GaN HEMT toward enhancement-mode operation. The self-terminated precision gate recess realized by inserting thin AlN/GaN bilayer in the AlGaN barrier layer. stopped automatically at insertion layer after high-temperature oxidation and wet etch, leaving to maintain quantum well channel that normally pinched off. With addition of an Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...
In this letter, we demonstrate a recessed-anode Schottky barrier diode (SBD) on double AlGaN/GaN heterojunction structure. A self-terminated, oxidation/wet etching with low-pressure chemical vapor deposition (LPCVD) Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> mask is applied in the anode recess process. Unlike common plasma-based, dry techniques, etched surface not subjected to...
We demonstrate a smart sensor for label-free multicomponent chemical analysis using single ring resonator to acquire the entire resonant spectrum of mixture and neural network model predict composition analysis. The shows high prediction accuracy with low root-mean-squared error ranging only from 0.13 2.28 mg/mL. predicted concentrations each component in testing dataset almost all fall within 95% bands. With its simple detection strategy accuracy, promises great potential applications many fields.
To assess GaN power transistors' capability to maintain a decent E-mode operation, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {th}}$ </tex-math></inline-formula> at high {DS}}$ is measured for Schottky-type p-GaN gate HEMT, and an excessive negative shift observed. With {DS}} =1$ V, around 1.3 V notation="LaTeX">${I}_{\text {D}} mA, but drops by ~0.6 when of 100 V. In comparison, ohmic-type...
In this paper, we report the device performance of a high-voltage enhancement-mode (E-mode) GaN MOSHEMT on silicon substrate. Normally off operation is realized by self-terminated precision gate recess process an optimized high-electron mobility transistor structure. The fully pinched at zero bias, suggesting "true" normally operation. threshold voltage 0.4 V with drain current density 1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML"...
The application of artificial intelligence diagnosis based on deep learning in the medical field has been widely accepted. We aimed to evaluate convolutional neural networks (CNNs) for automated classification and detection recurrent aphthous ulcerations (RAU), normal oral mucosa, other common mucosal diseases clinical photographs.
To assess GaN power transistors' capability to maintain a decent enhancement-mode operation under high voltage switching operation, the impact of negative threshold ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) shift on false turn- <sc xmlns:xlink="http://www.w3.org/1999/xlink">on</small> Schottky-type p-GaN gate high-electron mobility transistor (HEMT) is analyzed. The...
The temperature dependence of current collapse (CC) in AlGaN/GaN high-electron mobility transistors on silicon substrate is studied this paper. Devices without and with Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> passivation are used to investigate the behavior surface- buffer-induced CC, respectively. It found that degree surface-induced CC unpassivated devices has a weak...
A gate-recessed normally OFF GaN metal-oxide-semiconductor high-electron-mobility transistor on silicon substrate has been fabricated using a self-terminated, plasma-free oxidation and wet etching process with pre-recess low-pressure chemical vapor deposition (LPCVD) Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> passivation layer. The LPCVD serves the dual role of gate-recess mask...
A novel gate and passivation dielectric stack consisting of a thin metal-organic chemical vapor deposition (MOCVD) grown in-situ Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> (3 nm) thick lowpressure (LPCVD) (30 in AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistor (MIS-HEMT) is proposed. The quality the /(Al)GaN interface effect on threshold voltage (V...
This paper presents a new two-dimensional (2D) simulator, which can simulate the etching polymerization alternation in Bosch process for an infinite trench. Physical models and deposition are developed. Having been implemented with these string–cell hybrid method based on string structure cell structure, this simulator has ability to of different material types. After model parameter extraction from experiments, is used several phenomena process, including formation adjustment sidewall...
This paper presents a design method of force rebalance control for the sense mode micromachined vibratory gyroscope with multiobjective. The strategy is mainly based on constraining sensitivity margin specifications via numerical optimization approach, which embeds in closed-loop system to possess more robust performance. also provides quantitative methodology configuring parameters realize functional electrostatic feedback microgyroscope case nonideal coupling and external angular...
This Letter presents the design and implementation of a highly symmetric microelectromechanical system sandwich accelerometer using double-device-layer silicon-on-insulator (D-SOI) wafer. The proof mass though-wafer-thickness is suspended by eight L-shaped beams mirror-symmetrically. suspension provides flexible mechanical without large chip area consumption. Therefore immune from trade-off between sensing capacitance structure flexibility. mode (first vibration mode) successfully decoupled...
AlGaN/GaN high-electron-mobility transistor (HEMT) based pH sensors have the advantages of fast response and high stability, can be used in harsh environments. This paper presents a sensor on planar dual-gate HEMT cascode amplifier, which increase sensitivity for about 45 times from mV/pH to 2.06 V/pH with linearity 1.27%. The results indicate that it is possible improve at origin detecting instead subsequent complex amplifier circuits. proposed device has also shown capacity adjust sensor's...
In this study, a time-resolved extraction method is developed to investigate the threshold voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {th}}{)}$ </tex-math></inline-formula> of Schottky-type p-GaN gate high electron mobility transistor (HEMT) biased at {DS}}$ . A testing platform built which applies triangular waveform and extracts {th}}$ when drain current equals 10 mA. device up...
AlGaN/GaN metal oxide semiconductor high electron mobility transistors (MOSHEMTs) with thick <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$({>}{\rm 35}~{\rm nm})$</tex></formula> , high- Notation="TeX">$\kappa~({\rm TiO}_{{2}}/{\rm NiO})$</tex> </formula> submicrometer-footprint (0.4 Notation="TeX">$\mu{\rm m}$</tex></formula> ) gate dielectric are found to exhibit two orders of magnitude in...
Threshold voltage drift under gate bias stress was investigated in gate-recessed enhancement mode (E-mode) GaN MOSFET and depletion (D-mode) MOS high-electron-mobility transistor (MOSHEMT) with Al2O3 dielectric layer. Besides the positive shift of threshold both devices stress, it is also found that could exist E-mode negative while observed D-mode MOSHEMT. A three-step trapping detrapping process drain current transient device after stress. It suggested electron injection following...