A5101980024- GaN-based semiconductor devices and materials
- Topological Materials and Phenomena
- Ga2O3 and related materials
- Semiconductor materials and devices
- Graphene research and applications
- Physics of Superconductivity and Magnetism
- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- 2D Materials and Applications
- Silicon Carbide Semiconductor Technologies
- Advanced Condensed Matter Physics
- ZnO doping and properties
- Quantum many-body systems
- Semiconductor materials and interfaces
- Advancements in Semiconductor Devices and Circuit Design
- Advanced MEMS and NEMS Technologies
- Radio Frequency Integrated Circuit Design
- Advanced Surface Polishing Techniques
- Advanced Thermoelectric Materials and Devices
- Surface and Thin Film Phenomena
- Magnetic properties of thin films
- Rare-earth and actinide compounds
- Quantum Mechanics and Non-Hermitian Physics
- Mechanical and Optical Resonators
- MXene and MAX Phase Materials
Institute of Microelectronics
2006-2025
Chinese Academy of Sciences
2016-2025
University of Chinese Academy of Sciences
2017-2024
Institute of Physics
2008-2023
Songshan Lake Materials Laboratory
2019-2021
Czech Academy of Sciences, Institute of Physics
2017-2019
National Laboratory for Superconductivity
2008-2015
Peking University
2005-2006
(Al)GaN recess-free normally OFF technology is developed for fabrication of high-yield lateral GaN-based power devices. The process achieved by an ultrathin-barrier (UTB) AlGaN/GaN heterostructure that features a natural pinched-off 2-D electron gas channel. top-down manufacturing technique overcomes the challenges in etching AlGaN barrier with well-controlled depth and uniformity, which especially attractive high-electron-mobility transistors (HEMTs) metal-insulator-semiconductor HEMTs...
Majarona fermions (MFs) were predicted more than seven decades ago but are yet to be identified [1]. Recently, much attention has been paid search for MFs in condensed matter systems [2-10]. One of the seaching schemes is create MF at interface between an s-wave superconductor (SC) and a 3D topological insulator (TI) [11-13]. Experimentally, progresses have achieved observations proximity-effect-induced supercurrent [14-16], perfect Andreev reflection [17] conductance peak Fermi level [18]....
Abstract Two-dimensional transition metal dichalcogenides MX 2 ( M = W, Mo, Nb, and X Te, Se, S) with strong spin–orbit coupling possess plenty of novel physics including superconductivity. Due to the Ising coupling, monolayer NbSe gated MoS H structure can realize superconductivity, which manifests itself in-plane upper critical field far exceeding Pauli paramagnetic limit. Surprisingly, we find that a few-layer 1 T d MoTe also exhibits an goes beyond Importantly, shows emergent two-fold...
This letter presents a meticulously designed gate structure featuring SiNx/AlN staggered stack on GaN <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${p}$ </tex-math></inline-formula> -channel field-effect transistors ( -FETs) to enhance the modulation capability of gate. It is found that insertion 4 nm plasma enhanced atomic layer deposition (PEALD) AlN between SiNx dielectric and recessed...
We have investigated the conductance spectra of Sn-Bi2Se3 interface junctions down to 250 mK and in different magnetic fields. A number anomalies were observed below superconducting transition temperature Sn, including a small gap from that zero-bias peak growing up at lower temperatures. discussed possible origins smaller peak. These phenomena support proximity-effect-induced chiral phase is formed between Sn strong spin-orbit coupling material Bi2Se3.
In this letter, an enhancement-mode (E-mode) GaN p-channel field-effect transistors (p-FETs) with current density of −5.6 mA/mm and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I} _{{\mathrm {ON}}}/{I} {OFF}}}$ </tex-math></inline-formula> ratio 10 <sup xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> was demonstrated on a p-GaN/AlN/AlGaN/GaN heterostructure Si substrate. A decent ohmic contact...
Gallium nitride (GaN) has been considered one of the most promising materials for next-generation power and radio-frequency electronic devices, as they can operate at higher voltage, frequency, temperature, compared with their silicon (Si) counterparts. However, fresh GaN surface is susceptible to natural oxidation composed Ga2O3, Ga2O, other intermediate states. Moreover, oxidized no longer features distinct atomic step-terrace morphology, resulting in a degraded interface when gate or...
We have studied the electron transport properties of topological insulator-related material Bi${}_{2}$Se${}_{3}$ near superconducting Pb-Bi${}_{2}$Se${}_{3}$ interface, and found that a state is induced over an extended volume in Bi${}_{2}$Se${}_{3}$. This can carry Josephson supercurrent, demonstrates gaplike structure conductance spectra as probed by normal-metal electrode. The establishment gap not confining electrons into narrow space close to superconductor-normal metal previously...
The strong spin$-$orbit coupling (SOC) and numerous crystal phases in few$-$layer transition metal dichalcogenides (TMDCs) MX$_2$ (M$=$W, Mo, X$=$Te, Se, S) has led to a variety of novel physics, such as Ising superconductivity quantum spin Hall effect realized monolayer 2H$-$ Td$-$MX$_2$, respectively. Consecutive tailoring the structure from 2H Td phase may realize long$-$sought topological one material system by incorporating together. In this work, combing Raman spectrum, X-ray...
High-performance AlGaN/GaN-on-Si diodes are fabricated with lateral Schottky barrier controlled rectifier (LSBS) on thin-barrier (5nm) AlGaN/GaN heterostructures, which features a recess-free process, enabling better electrostatic control to pinch off the channel under anode region. In this way, low leakage currents (3-orders of magnitude lower than conventional recessed Schottky-barrier-diode (SBD)) and high reverse breakdown voltage 1700 V (@10μA/mm) reached, together onset only 0.37...
A silicon nitride (SiNx) film deposited at 500 °C by plasma-enhanced atomic layer deposition (PEALD) is employed as the gate dielectric for GaN-based metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs). An interface enhancement technology featuring in situ low-damage NH3/N2 remote plasma pretreatments (RPPs) developed prior to SiNx deposition, which contributes an improved surface morphology while remarkably suppressed oxides. It revealed constant-capacitance...
A physical insight into the capture and emission behavior of interface/oxide states in a GaN-based metal-oxide-semiconductor (MOS) structure is great importance to understanding threshold voltage (VTH) instability GaN power transistors. time-dependent VTH shift Ni/Al2O3/AlGaN/GaN MOS-HFETs (heterojunction field-effect transistors) distribution Al2O3/III-nitride interface (Dit) were successfully characterized by constant-capacitance deep level transient spectroscopy. It found that situ remote...
Many proposals for exploring topological quantum computation are based on superconducting devices constructed materials with strong spin-orbit coupling (SOC). For these devices, full control of both the magnitude and spatial distribution supercurrent is highly demanded, but has been elusive up to now. We a proximity-type Josephson junction nanoplates Bi2O2Se, new emerging semiconductor SOC. Through electrical gating, we show that can be fully turned ON OFF, its real-space pathways configured...
Electrical control of spin dynamics in ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ was investigated ring-type interferometers. Aharonov-Bohm and Altshuler-Aronov-Spivak resistance oscillations against a magnetic field, Aharonov-Casher the gate voltage were observed presence Berry phase $\ensuremath{\pi}$. A very large tunability precession angle by has been obtained, indicating that ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$-related materials with strong spin-orbit coupling are promising candidates for...
Monolithically integrated enhancement/depletion-mode (E/D-mode) GaN-based metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) and inverters, were fabricated on an ultrathin-barrier (UTB) AlGaN/GaN heterostructure grown Si substrates. By employing a graded AlGaN back barrier in the UTB-AlGaN/GaN heterostructure, high threshold voltage (VTH) of +3.3 V is achieved E-mode MIS-HEMTs. The MIS-HEMT inverter features logic swing 7.76 at supply 8 V, small VTH—hysteresis as...
The physical mechanism for recovery of 2D electron gas (2DEG) in down-scaled AlGaN/GaN heterostructures with SiNx layers grown by low-pressure chemical vapor deposition (LPCVD) was investigated means Hall-effect characterization, scanning Kelvin probe microscopy (SKPM), and self-consistent Poisson–Schrödinger calculations. Observations using SKPM show that the surface potential heterostructure remained nearly unchanged (∼1.08 eV) as thickness AlGaN barrier reduced from 18.5 to 5.5 nm likely...
In search of fault-tolerant topological quantum computation (TQC), zero-bias conductance peak as a necessary signature Majorana zero modes (MZMs) has been observed in number solid-state systems. Here, we present the MZMs from phase-sensitive experiment on Josephson trijunctions constructed surface three-dimensional insulators. We that minigap at center trijunction is protected to close over extended regions phase space, supporting principle diagram proposed by Fu and Kane 2008. Our study...
A drain-controlled current-mode deep level transient spectroscopy (I-DLTS), was developed for investigation of Semi-ON-state current collapse in AlGaN/GaN high electron mobility transistors (HEMTs). By inserting a graded AlGaN back-barrier between the GaN channel and buffer layer, hot-electron effect induced charging traps is effectively blocked, which contributes to remarkable suppressed HEMTs under stress. broad-distributed trap <inline-formula...
There have been continuous efforts in searching for unconventional superconductivity the past five decades. Compared to well-established $d$-wave cuprates, existence of with pairing symmetries other high angular momentum is less conclusive. Bi/Ni epitaxial bilayer a potential superconductor broken time reversal symmetry (TRS), that it demonstrates and ferromagnetism simultaneously at low temperatures. We employ specially designed superconducting quantum interference device (SQUID) detect, on...
Abstract Enhancement-mode (E-mode) GaN-on-Si radio-frequency (RF) high-electron-mobility transistors (HEMTs) were fabricated on an ultrathin-barrier (UTB) AlGaN (<6 nm)/GaN heterostructure featuring a naturally depleted 2-D electron gas (2DEG) channel. The E-mode HEMTs exhibit relatively high threshold voltage ( V TH ) of +1.1 with good uniformity. A maximum current/power gain cut-off frequency f T / MAX 31.3/99.6 GHz power added efficiency (PAE) 52.47% and output density P out 1.0 W/mm...
An ultra-deep (40–120 µm) keyhole-free electrical isolation trench with an aspect ratio of more than 20:1 has been fabricated. The process combines DRIE (deep reactive ion etch), LPCVD insulating materials refilling and TMAH or KOH backside etching technologies. Employing multi-step optimized conditions a sacrificial polysilicon layer, the keyholes in trenches are prevented; as result mechanical strength reliability improved. Electrical tests show that such can electrically isolate MEMS...