Application of GaAs-AlGaAs Superlattice Structure for Fabricating High Breakdown Voltage Power MISFET

1989 ◽  
Vol 160 ◽  
Author(s):  
W.C. Liu ◽  
W.S. Lour ◽  
R.L. Wang ◽  
C.Y. Sun ◽  
W.C. Hsu
Keyword(s):  
Buffer Layer ◽  
Breakdown Voltage ◽  
Deep Level ◽  
Drain Current ◽  
Low Noise ◽  
Gate Insulator ◽  
Superlattice Structure ◽  
Active Channel ◽  
Buffer Structure ◽  
Impurities And Defects

AbstractA new power MISFET with undoped GaAs-Al0.3Ga0.7As superlattice gate “insulator” and buffer structure has been fabricated successfully. The superlattice gate “insulator” exhibits a much higher gate breakdown voltage( >35V) with very low prebreakdown leakage current and a lower gate capacitance (C ). Due to the existence of gate “insulator”, a higher carrier concentration can be employed in the active channel which improves the output drain current capability and transconductance. If the gate length is reduced to 1 um, a higher transconductance up to 330 mS/mm can be expected.The insertion of superlattice buffer structure, between active channel and buffer layer offers an excellent carrier confinement barrier and gives an interface degraded region smaller than 40A. In addition, the superlattice buffer structure can getter greatly deep level impurities and defects from substrate or buffer layer. In summary, the proposed MISFET structure is suitable for high power, high frequency and low noise applications.

AlGaN Channel HEMT with Extremely High Breakdown Voltage

2011 ◽  
Vol 1324 ◽  
Author(s):  
Takuma Nanjo ◽  
Misaichi Takeuchi ◽  
Akifumi Imai ◽  
Yousuke Suzuki ◽  
Muneyoshi Suita ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Drain Current ◽  
High Electron Mobility Transistors ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
High Electron ◽  
Field Plate ◽  
Electron Mobility Transistors ◽  
Doping Technique ◽  
Resistive Source

ABSTRACTA channel layer substitution of a wider bandgap AlGaN for a conventional GaN in high electron mobility transistors (HEMTs) is an effective method of enhancing the breakdown voltage. Wider bandgap AlGaN, however, should also increase the ohmic contact resistance. Si ion implantation doping technique was utilized to achieve sufficiently low resistive source/drain contacts. The fabricated AlGaN channel HEMTs with the field plate structure demonstrated good pinch-off operation with sufficiently high drain current density of 0.5 A/mm without noticeable current collapse. The obtained maximum breakdown voltages was 1700 V in the AlGaN channel HEMT with the gate-drain distance of 10 μm. These remarkable results indicate that AlGaN channel HEMTs could become future strong candidates for not only high-frequency devices such as low noise amplifiers but also high-power devices such as switching applications.

Off-state drain current and breakdown voltage of AlGaN/GaN MIS-HEMT with multilayered gate insulator

2007 ◽  
Vol 4 (7) ◽  
pp. 2682-2685 ◽  
Author(s):  
S. Yagi ◽  
M. Shimizu ◽  
M. Inada ◽  
H. Okumura ◽  
H. Ohashi ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Drain Current ◽  
Gate Insulator

scholarly journals Investigation of 1/f and Lorentzian Noise in TMAH-treated Normally-Off GaN MISFETs

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 717
Author(s):  
Ki-Sik Im ◽  
Mallem Siva Pratap Reddy ◽  
Yeo Jin Choi ◽  
Youngmin Hwang ◽  
Sung Jin An ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Deep Level ◽  
Low Frequency ◽  
Ammonium Hydroxide ◽  
Gate Insulator ◽  
Frequency Noise ◽  
Tetramethyl Ammonium Hydroxide ◽  
Shallow Traps ◽  
Gan Buffer Layer ◽  
Mobility Fluctuations

A tetramethyl ammonium hydroxide (TMAH)-treated normally-off Gallum nitride (GaN) metal-insulator-semiconductor field-effect transistor (MISFET) was fabricated and characterized using low-frequency noise (LFN) measurements in order to find the conduction mechanism and analyze the trapping behavior into the gate insulator as well as the GaN buffer layer. At the on-state, the noise spectra in the fabricated GaN device were 1/fγ properties with γ ≈ 1, which is explained by correlated mobility fluctuations (CMF). On the other hand, the device exhibited Lorentzian or generation-recombination (g-r) noises at the off-state due to deep-level trapping/de-trapping into the GaN buffer layer. The trap time constants (τi) calculated from the g-r noises became longer when the drain voltage increased up to 5 V, which was attributed to deep-level traps rather than shallow traps. The severe drain lag was also investigated from pulsed I-V measurement, which is supported by the noise behavior observed at the off-state.

Fabrication of AlGaN/GaN HFET with a High Breakdown Voltage on 4-inch Si (111) Substrate by MOVPE

2006 ◽  
Vol 955 ◽  
Author(s):  
Yuki Niiyama ◽  
Sadahiro Kato ◽  
Yoshihiro Sato ◽  
Masayuki Iwami ◽  
Jiang Li ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Breakdown Voltage ◽  
Field Effect Transistor ◽  
Drain Current ◽  
Growth Pressure ◽  
Si Substrates ◽  
Effect Transistor ◽  
Gan Heterostructure ◽  
Gan Film ◽  
Gan Buffer Layer

ABSTRACTWe investigated an AlGaN/GaN heterostructure field effect transistor (HFET) on Si substrates using a multi-wafer metalorganic vapor phase epitaxy (MOVPE) system. It was confirmed that a GaN film with smooth surface and without any crack was obtained. To increase a resistance of a GaN buffer layer, the carbon (C) -doping was carried out by controlling the V/III ratio and the growth pressure. The breakdown voltage of the buffer layer was dramatically improved by introducing the C. As a result, the breakdown voltage was about 900 V when the C concentration was about ∼8×1018 cm−3. After while, an AlGaN/GaN heterojunction FET (HFET) on a C-doped GaN buffer layer was fabricated. We achieved the breakdown voltage of over 1000 V and the maximum drain current of over 150 mA/mm, respectively. It was found that the C doped buffer layer is very effective for improving the breakdown voltage of AlGaN/GaN HFETs.

The Role of Substrate Compensation on DC Characteristics of 4H-SiC MESFET with Buffer Layer: A Combined Two-Dimensional Simulations and Analytical Study

2014 ◽  
Vol 778-780 ◽  
pp. 887-890 ◽  
Author(s):  
M. Hema Lata Rao ◽  
Neti.V.L. Narasimha Murty
Keyword(s):  
Buffer Layer ◽  
Electron Concentration ◽  
Deep Level ◽  
Concentration Profiles ◽  
Two Dimensional ◽  
Dc Characteristics ◽  
Proposed Model ◽  
Effect Transistor ◽  
Active Channel

An analytical model of 4H-SiC metal semiconductor field effect transistor (MESFET) is proposed with buffer layer on high purity semi-insulating (HPSI) 4H-SiC substrate compensated by multiple deep level traps. The contribution of deep level traps (DLT) is projected and verified using two-dimensional simulations (Silvaco®). The modeled DC characteristics are compared with two-dimensional simulations performed on the same device as considered in the analytical model.The 4H-SiC MESFET is simulated with and without the effect of buffer layer and the electron concentration profiles in different regions are observed from two-dimensional simulations.The electron concentration profiles obtained at channel-substrate interface clearly shows that when the buffer layer is not present, the channel electrons get trapped by the deep level traps used for substrate compensation. It is also observed that the inclusion of buffer layer minimizes the extent of electron trapping by screening out the active channel from the substrate. However, the trapping phenomena take place in both the cases.We believe that the proposed model of 4H-SiC MESFET which includes the substrate compensation through multiple deep level traps may be useful for realizing SiC based monolithic circuits (MMICs) on HPSI substrates.

AlGaN/GaN MIS-HEMTs with a p-GaN Cap Layer

MRS Advances ◽  
2017 ◽  
Vol 3 (3) ◽  
pp. 143-146
Author(s):  
Che-Ching Hsu ◽  
Pei-Chien Shen ◽  
Yi-Nan Zhong ◽  
Yue-Ming Hsin
Keyword(s):  
Leakage Current ◽  
Breakdown Voltage ◽  
Drain Current ◽  
Gate Insulator ◽  
Current Ratio ◽  
Dc Characteristics ◽  
Cap Layer

ABSTRACTIn this study, AlGaN/GaN MIS-HEMTs with a p-GaN cap layer and ALD deposited Al2O3 gate insulator were fabricated. Devices with two different thicknesses of p-GaN cap layers were investigated and compared. AlGaN/GaN MIS-HEMT with an 8-nm p-GaN cap showed a better DC characteristics than device with a 5-nm p-GaN cap. The drain current of 662.9 mA/mm, a high on/off current ratio of 2.67×109 and a breakdown voltage of 672 V were measured in device with an 8-nm p-GaN cap. In addition, lateral leakage current was investigated by using adjacent MIS gate structures with a separation of 3 μm to investigate the leakage current.

Top-gate amorphous IGZO thin-film transistors with a SiO buffer layer inserted between active channel layer and gate insulator

2012 ◽  
Vol 12 (1) ◽  
pp. 228-232 ◽  
Author(s):  
F. Zhou ◽  
H.P. Lin ◽  
L. Zhang ◽  
J. Li ◽  
X.W. Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Buffer Layer ◽  
Thin Film Transistors ◽  
Gate Insulator ◽  
Channel Layer ◽  
Active Channel

Wide range modulation of synaptic weight in thin-film transistors with hafnium oxide gate insulator and indium-zinc oxide channel layer for artificial synapse application

Nanoscale ◽  
2021 ◽  
Author(s):  
Keonwon Beom ◽  
Jimin Han ◽  
Hyun-Mi Kim ◽  
Tae-Sik Yoon
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Thin Film Transistors ◽  
Hafnium Oxide ◽  
Synaptic Weight ◽  
Drain Current ◽  
Gate Insulator ◽  
Channel Layer ◽  
Indium Zinc Oxide ◽  
Wide Range

Wide range synaptic weight modulation with a tunable drain current was demonstrated in thin-film transistors (TFTs) with a hafnium oxide (HfO2−x) gate insulator and an indium-zinc oxide (IZO) channel layer...

scholarly journals Noise and Breakdown Characterization of SPAD Detectors with Time-Gated Photon-Counting Operation

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5287
Author(s):  
Hiwa Mahmoudi ◽  
Michael Hofbauer ◽  
Bernhard Goll ◽  
Horst Zimmermann
Keyword(s):  
Breakdown Voltage ◽  
Single Photon ◽  
Photon Counting ◽  
Low Noise ◽  
Dark Count ◽  
Fully Integrated ◽  
Trade Offs ◽  
And Performance ◽  
Noise Models

Being ready-to-detect over a certain portion of time makes the time-gated single-photon avalanche diode (SPAD) an attractive candidate for low-noise photon-counting applications. A careful SPAD noise and performance characterization, however, is critical to avoid time-consuming experimental optimization and redesign iterations for such applications. Here, we present an extensive empirical study of the breakdown voltage, as well as the dark-count and afterpulsing noise mechanisms for a fully integrated time-gated SPAD detector in 0.35-μm CMOS based on experimental data acquired in a dark condition. An “effective” SPAD breakdown voltage is introduced to enable efficient characterization and modeling of the dark-count and afterpulsing probabilities with respect to the excess bias voltage and the gating duration time. The presented breakdown and noise models will allow for accurate modeling and optimization of SPAD-based detector designs, where the SPAD noise can impose severe trade-offs with speed and sensitivity as is shown via an example.

scholarly journals Improvement of DC Breakdown Strength of the Epoxy/POSS Nanocomposite by Tailoring Interfacial Electron Trap Characteristics

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1298
Author(s):  
Farooq Aslam ◽  
Zhen Li ◽  
Guanghao Qu ◽  
Yang Feng ◽  
Shijun Li ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Breakdown Voltage ◽  
Breakdown Strength ◽  
Deep Level ◽  
Simulation Method ◽  
Neat Epoxy ◽  
Interfacial Region ◽  
Chemical Calculation ◽  
Oligomeric Silsesquioxane ◽  
Underlying Risk

To date, breakdown voltage is an underlying risk to the epoxy-based electrical high voltage (HV) equipment. To improve the breakdown strength of epoxy resin and to explore the formation of charge traps, in this study, two types of polyhedral oligomeric silsesquioxane (POSS) fillers are doped into epoxy resin. The breakdown voltage test is performed to investigate the breakdown strength of neat epoxy and epoxy/POSS composites. Electron traps that play an important role in breakdown strength are characterized by thermally stimulated depolarized current (TSDC) measurement. A quantum chemical calculation tool identifies the source of traps. It is found that adding octa-glycidyl POSS (OG-POSS) to epoxy enhances the breakdown strength than that of neat epoxy and epoxycyclohexyl POSS (ECH-POSS) incorporated epoxy. Moreover, side groups of OG-POSS possess higher electron affinity (EA) and large electronegativity that introduces deep-level traps into epoxy resin and restrain the electron transport. In this work, the origin of traps has been investigated by the simulation method. It is revealed that the functional properties of POSS side group can tailor an extensive network of deep traps in the interfacial region with epoxy and enhance the breakdown strength of the epoxy/POSS nanocomposite.

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