A5084389947- GaN-based semiconductor devices and materials
- Ga2O3 and related materials
- Semiconductor materials and devices
- ZnO doping and properties
- Silicon Carbide Semiconductor Technologies
- Semiconductor Quantum Structures and Devices
- Metal and Thin Film Mechanics
- Copper-based nanomaterials and applications
- Advancements in Semiconductor Devices and Circuit Design
- Gas Sensing Nanomaterials and Sensors
- Acoustic Wave Resonator Technologies
Nagoya Institute of Technology
2010-2018
Loyola University Chicago
2010
Gallium nitride (GaN) is a compound semiconductor that has tremendous potential to facilitate economic growth in industry silicon-based and currently faced with diminishing returns of performance versus cost investment. At material level, its high electric field strength electron mobility have already shown for frequency communications photonic applications. Advances on commercially viable large area substrates are now at the point where power conversion applications GaN cusp...
We report recessed-gate Al2O3/AlGaN/GaN normally-OFF metal–oxide–semiconductor high-electron-mobility transistors (MOS-HEMTs) on 8 in. Si. The MOS-HEMTs showed a maximum drain current of 300 mA/mm with high threshold voltage +2.4 V. quite low subthreshold leakage (∼10−8 mA/mm) yielded an excellent ON/OFF ratio (9 × 108) small, stable slope 74 mV/dec. An atomic-layer-deposited Al2O3 layer effectively passivates, as no significant dispersions were observed. A OFF-state breakdown 825 V was...
In this paper, we report on the enhancement-mode (E-mode) Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /AlGaN/GaN metal-oxide-semiconductor high-electron mobility transistors (MOS-HEMTs) Si. The E-mode operation is due to negative charges in atomic layer deposited layer. unrecessed MOS-HEMTs exhibit high drain current density with a low specific ON-state resistance (R...
Frequency dependent conductance measurements were employed to study the trapping effects of in-situ metal-organic chemical vapor deposition grown AlN/AlGaN/GaN metal-insulator-semiconductor heterostructures (MISHs). Conventional fitting method could not be used explain experimental parallel (Gp/ω ) results. Alternatively, Gp/ω values resolved into two curves for gate voltages (−1.2 −1.8 V) near threshold voltage (Vth) by a model. In low frequency region (≤50 kHz), can fitted single curve. On...
A study of metal‐organic chemical vapor deposition (MOCVD) grown AlN nucleation layer (NL) on breakdown characteristics for GaN‐on‐Si is presented. It widely believed that NL can act as an insulator because its large band gap ∼6.2 eV. On contrary, this NL/Si reveals conductive nature and shows high vertical leakage. The structural examinations along with electrical characterization show quality depends the growth temperature. surface morphology presence unintentional oxygen impurities govern...
Abstract We report novel GaN fully vertical p–n diode on Si grown by metalorganic chemical vapor deposition. The thick strained layer superlattice is effective in controlling a doping level of 10 16 cm −3 an n − -GaN drift layer. exhibits differential on-resistance R 7.4 mΩ 2 , turn-on voltage 3.4 V, and breakdown V B 288 V. corresponding Baliga’s figure merit (FOM) 11.2 MW/cm . A good FOM value for the GaN-on-Si realized thickness 1.5 µm without using substrate removal technology.
Al2O3 deposited by atomic layer deposition (ALD) was used as an insulator in metal–insulator–semiconductor (MIS) structures for GaN-based MIS-devices. As the oxygen precursors ALD process, water (H2O), ozone (O3), and both H2O O3 were used. The chemical characteristics of ALD-Al2O3 surfaces investigated x-ray photoelectron spectroscopy. After fabrication MIS-diodes MIS-high-electron-mobility transistors (MIS-HEMTs) with ALD-Al2O3, their electrical properties evaluated current–voltage (I–V)...
This letter reports on the epitaxial growth and device fabrication of metal-organic chemical vapor deposition grown fully vertical GaN-on-Si p-n diodes. A strong dependence in electrical characteristics n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> -GaN drift layer was revealed by analyzing threading dislocations, carrier properties layers current-voltage fabricated Further, our diode with a 2.3-μm-thick exhibited an on-resistance...
We report on the analyses of trapping properties metal-organic chemical vapor deposition grown AlGaN/GaN high-electron-mobility transistor (HEMT) heterostructures silicon with increasing buffer thickness (Tbuff). An exact exponential dependence hetero-interface trap time constants gate bias was observed in vicinity threshold voltage. A low state density (Dit) value ∼2.5 × 1010 cm−2 eV−1 achieved for by using thick Tbuff ∼ 5 μm against a Dit ∼1 1011 similar thin 1.25 μm. Further, high...
A normally-Off metal-oxide-semiconductor field-effect transistor (MOS-FET) is proposed by using AlInN/AlGaN heterostructure grown on silicon. The AlGaN channel MOSFET with Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> layer as gate insulator exhibits a drain current of 90 mA/mm at the bias +8 V, an ON/OFF drain-current ratio <inline-formula...
We report on In0.25Al0.75N/GaN heterostructures grown Si using a graded buffer and thick strained-layer superlattice. These showed smooth surface with root mean square value of 0.2 nm, high sheet carrier density 1.7 × 1013 cm−2, Hall mobility 1100 cm2 V−1 s−1. The high-electron-mobility transistors (HEMTs) drain current 755 mA/mm low specific on-resistance 0.39 mΩ·cm2. Furthermore, HEMT the gate–drain spacing 20 µm power device figure-of-merit 1.62 108 V2 Ω−1 cm−2.
The authors report on Al2O3/Al0.85In0.15N/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistor (MOS-HEMT) Si fabricated by using atomic layer deposited Al2O3 as gate insulator and passivation layer. MOS-HEMT with the length of 2 μm exhibits excellent direct-current (dc) characteristics a drain current maximum 1270 mA/mm at bias 3 V an off-state breakdown voltage 180 for gate-drain spacing 4 μm. Also, 1 μm-gate shows good radio-frequency (rf) response such gain oscillation cut-off...
A nearly lattice-matched In0.12Al0.88N/Al0.21Ga0.79N heterostructure field-effect transistor (HFET) was fabricated and its device characteristics were evaluated. The showed good pinch-off with a high breakdown field of 118 V/μm. simple calculation based on the experimental results possibility that low specific on-resistance below those conventional AlGaN-channel HFETs can be achieved for InAlN/AlGaN in case where contact resistivity is less than 1 × 10−5 Ω cm2.
A synthetic route for alumina based dielectric layer AlGaN/GaN metal–oxide–semiconductor high-electron-mobility transistors (MOS-HEMT) has been developed. The approach is on oxidative annealing of thin Al deposited prior to Schottky gate metallization. MOS-HEMT exhibits good pinch off features with I dsmax and g mmax 421 mA/mm 121 mS/mm, respectively. Frequency dependent conductance measurements yielded a minimum trap density ( D T ) transient time 2.2 ×10 12 cm -2 eV -1 1.3 µs, oxide...
The trapping properties of in-situ metal-organic chemical vapor deposition (MOCVD) grown AlN/AlGaN/GaN metal-insulator-semiconductor heterostructure field-effect transistors (MIS-HFETs) with AlN layers at 600 and 700 °C has been quantitatively analyzed by frequency dependent parallel conductance technique. Both the devices exhibited two kinds traps densities, due to (DT-AlN) AlGaN (DT-AlGaN) respectively. MIS-HFET showed a minimum DT-AlN DT-AlGaN 1.1 x 1011 1.2 1010 cm-2eV-1 energy levels...
In this letter, a gate-recessed Al2O3/InAlN/GaN normally-OFF metal–oxide–semiconductor high-electron-mobility transistor (MOS-HEMT) on Si is reported. The fabricated MOS-HEMT with gate length of 1.5 µm features high drain current density 840 mA/mm at bias (Vgs) +8 V, low specific ON-resistance 0.8 mΩ·cm2, and threshold voltage +1.9 V. also exhibits leakage (∼10−8 Vgs = V) maximum peak field-effect mobility 472 cm2 V−1 s−1. OFF-state breakdown the device (Lgd 4 µm) 278 V 0
Atomic layer deposition (ALD) using both water (H2O) and ozone (O3) as oxidants was performed to fabricate Al2O3/AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) on Si substrates, the effects of temperature electrical characteristics these MIS-HEMTs were investigated DC pulsed current–voltage measurements. The MIS-HEMT with Al2O3 deposited at 250 °C showed less drain current degradation in measurements, which consistent low minimum interface state...
The thermal stabilities of metal-organic chemical vapor deposition-grown lattice-matched InAlN/GaN/Si heterostructures have been reported by using slower and faster growth rates for the InAlN barrier layer in particular. temperature-dependent surface two-dimensional electron gas (2-DEG) properties these were investigated means atomic force microscopy, photoluminescence excitation spectroscopy, electrical characterization. Even at annealing temperature 850 °C, grown with a rate exhibited...
A synthetic route for alumina based dielectric layer AlGaN/GaN metal–oxide–semiconductor high-electron-mobility transistors (MOS-HEMT) has been developed. The approach is on oxidative annealing of thin Al deposited prior to Schottky gate metallization. MOS-HEMT exhibits good pinch off features with Idsmax and gmmax 421 mA/mm 121 mS/mm, respectively. Frequency dependent conductance measurements yielded a minimum trap density (DT) transient time (TT) 2.2 ×1012 cm-2 eV-1 1.3 µs, oxide...
We have demonstrated a vertical GaN-on-Si p-n diode with breakdown voltage (BV) as high 839 V by using low Si-doped strained layer superlattice (SLS). The fabricated the n−-SLS part of drift showed remarkable enhancement in BV, when compared conventional n−-GaN similar thickness. diodes 2.3 μm-thick and 3.0 exhibited differential on-resistance 4.0 Ω · cm2 BV V.
In the last decade, AlGaN/GaN based Enhancement-mode (E-mode) devices on Si substrate have been studied extensively [1-3]. spite of improvements in threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ), E-mode could not show high drain current density (I xmlns:xlink="http://www.w3.org/1999/xlink">dsmax</sub> which is highly desirable for automotive applications [4, 5]. Alternatively, InAlN/GaN are preferred...
Summary form only given. InAlN/GaN based high-electron-mobility transistors (HEMTs) are of immense interest due to its high power, speed and temperature capabilities. Lattice matched In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.18</sub> Al xmlns:xlink="http://www.w3.org/1999/xlink">0.82</sub> N/GaN HEMTs with polarization induced two-dimensional electron gas (2-DEG) can outperform AlGaN/GaN mitigate strain related issues [1-3]. Also,...
2014 International Conference on Solid State Devices and Materials,Reduction of Initial Threshold Voltage Shift in ALD-Al<sub>2</sub>O<sub>3</sub>/AlGaN/GaN MIS-HEMTs Si Substrates by Post-deposition Annealing