Logic Families Based on the Unipolar Devices

2007 ◽

Vol 556-557 ◽

pp. 975-978

Author(s):

Kent Bertilsson ◽

Chris I. Harris

Keyword(s):

Field Effect ◽

Field Effect Transistor ◽

Static Case ◽

Simulation Studies ◽

Drift Diffusion ◽

Element Approach ◽

Effect Transistor ◽

Unipolar Devices ◽

Very High ◽

Drift Layer

Both unipolar and injection SiC devices can be used for high voltage switching applications; it is not determined, however, for which applications one approach is preferred over the other. In this paper, simulation studies are used to compare the suitability of unipolar devices, in this case a JFET (Junction Field Effect Transistor) against an equivalent FCD (Field Controlled Diode) configuration up to very high voltages. The calculations are performed in a finite element approach, with commercial drift-diffusion software. Numerous drift layers have been simulated in a Monte-Carlo approach to ensure that the optimal design of the drift layers for different breakdown is used. In a static case, purely conductive losses in the drift layer in both unipolar and injection configuration are compared. Additionally the total losses are studied and compared in switched applications for different switching frequencies and current levels.

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SiC and unipolar devices

2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551) ◽

10.1109/pesc.2004.1355809 ◽

2004 ◽

Keyword(s):

Unipolar Devices

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4H-SIC Dmosfets for High Frequency Power Switching Applications

MRS Proceedings ◽

10.1557/proc-764-c2.7 ◽

2003 ◽

Vol 764 ◽

Cited By ~ 6

Author(s):

Sei-Hyung Ryu ◽

Anant K. Agarwal ◽

James Richmond ◽

John W. Palmour

Keyword(s):

High Voltage ◽

High Speed ◽

High Performance ◽

High Frequency Power ◽

Power Devices ◽

Power Switching ◽

High Speed Switching ◽

Unipolar Devices ◽

Very High ◽

Frequency Power

AbstractVery high critical field, reasonable bulk electron mobility, and high thermal conductivity make 4H-Silicon carbide very attractive for high voltage power devices. These advantages make high performance unipolar switching devices with blocking voltages greater than 1 kV possible in 4H-SiC. Several exploratory devices, such as vertical MOSFETs and JFETs, have been reported in SiC. However, most of the previous works were focused on high voltage aspects of the devices, and the high speed switching aspects of the SiC unipolar devices were largely neglected. In this paper, we report on the static and dynamic characteristics of our 4H-SiC DMOSFETs. A simple model of the on-state characteristics of 4H-SiC DMOSFETs is also presented.

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An Investigation on Resistive Switching Characteristics Induced by HfOx and Electrode Interfaces

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.645-646.169 ◽

2015 ◽

Vol 645-646 ◽

pp. 169-177

Author(s):

Xiao Rong Chen ◽

Jie Feng

Keyword(s):

Electric Field ◽

Resistive Switching ◽

Joule Heat ◽

Negative Bias ◽

Bipolar Resistive Switching ◽

Comparison And Analysis ◽

Switching Characteristics ◽

Different Characteristics ◽

Unipolar Devices ◽

Switching Devices

Pt/HfOx/Pt resistive switching devices with symmetric electrodes were fabricated. Bipolar resistive switching (RS) behaviors and unipolar behaviors were then observed under a positive/negative bias applied to the top electrode (TE). A comparison and analysis of bipolar/unipolar RS behaviors under different voltage polarities was then performed.The results demonstrated that bipolar RS was achieved via a drift of anion (O2-) under the electric field resulting in the rupture and recovery of filaments at the interface. When the filaments dissolved and formed at the interface near BE, the performance of the bipolar RS devices was better. However, for unipolar RS devices, when filaments dissolved and formed at the interface near TE, the performance was even better. These results indicated that a drift of O2-caused by electric field and a diffusion of O2-induced by Joule heat were the main reasons for unipolar RS. The different characteristics of the bipolar and unipolar devices can be attributed to the existence of a different number of defects at the active interface of the devices. This was where the rupture and recovery of filaments occurred. The results also indicate that the active interface is more important than other interfaces for RRAM performance.

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GaN/AlN Quantum Wells and Quantum Dots for Unipolar Devices at Telecommunication Wavelengths

10.1063/1.2729997 ◽

2007 ◽

Author(s):

Francois H. Julien ◽

Fabien Guillot ◽

Maria Tchernycheva ◽

Laetitia Doyennette ◽

Laurent Nevou ◽

...

Keyword(s):

Quantum Dots ◽

Quantum Wells ◽

Unipolar Devices

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Static and Dynamic Characterization of a 3.3 Kv, 45 A 4H-Sic MOSFET

Materials Science Forum ◽

10.4028/www.scientific.net/msf.924.739 ◽

2018 ◽

Vol 924 ◽

pp. 739-742 ◽

Cited By ~ 1

Author(s):

Anup Anurag ◽

Ghanshyamsinh Gohil ◽

Sayan Acharya ◽

Ki Jeong Han ◽

Kasunaidu Vechalapu ◽

...

Keyword(s):

Field Effect ◽

Field Effect Transistors ◽

Wide Bandgap ◽

Dynamic Characterization ◽

Medium Voltage ◽

Pulse Test ◽

Switching Performance ◽

Wide Bandgap Materials ◽

Unipolar Devices

Wide bandgap materials such as Silicon Carbide (SiC) has enabled the use of medium voltage unipolar devices like Metal-Oxide Field Effect Transistors (MOSFETs) and Junction Field Effect Transistors (JFETs), which can switch at much higher frequencies as compared to their silicon counterparts. It is therefore imperative to evaluate the performance of these medium voltage devices. In this paper, the static characterization and the switching performance of the new single die 3.3 kV, 45 A 4H-SiC MOSFET developed by Cree Inc are presented. The switching performance is measured through the conventional Double Pulse Test. Testing is done at a dc-link voltage of 1.5 kV for different values of current, and gate resistances.

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ENHANCING POWER ELECTRONIC DEVICES WITH WIDE BANDGAP SEMICONDUCTORS

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156406003837 ◽

2006 ◽

Vol 16 (02) ◽

pp. 545-556 ◽

Cited By ~ 3

Author(s):

BURAK OZPINECI ◽

MADHU SUDHAN CHINTHAVALI ◽

LEON M. TOLBERT

Keyword(s):

Silicon Carbide ◽

Field Strength ◽

Schottky Diodes ◽

Electronic Devices ◽

Wide Bandgap ◽

Power Electronic ◽

Different Temperatures ◽

Bandgap Semiconductors ◽

Switching Characteristics ◽

Unipolar Devices

Silicon carbide ( SiC ) unipolar devices have much higher breakdown voltages than silicon ( Si ) unipolar devices because of the ten times greater electric field strength of SiC compared with Si . 4H - SiC unipolar devices have higher switching speeds due to the higher bulk mobility of 4H - SiC compared to other polytypes. In this paper, four commercially available SiC Schottky diodes with different voltage and current ratings, VJFET, and MOSFET samples have been tested to characterize their performance at different temperatures ranging from -50°C to 175°C. Their forward characteristics and switching characteristics in this temperature range are presented. The characteristics of the SiC Schottky diodes are compared with those of a Si pn diode with comparable ratings.

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On the Active Volume of Cadmium Zinc Telluride Gamma-Ray Spectrometers

MRS Proceedings ◽

10.1557/proc-487-199 ◽

1997 ◽

Vol 487 ◽

Cited By ~ 1

Author(s):

J. C. Lund ◽

B. A. Brunett ◽

T. P. Viles ◽

N. R. Hilton ◽

R. B. James

Keyword(s):

Gamma Ray ◽

Cadmium Zinc Telluride ◽

Pulse Height ◽

Zinc Telluride ◽

Charge Trapping ◽

Active Volume ◽

Electronic Signal Processing ◽

Czt Detectors ◽

Unipolar Devices ◽

Cadmium Zinc

AbstractIn this paper we develop quantitative models to predict the active volume of cadmium zinc telluride (CZT) detectors operated as gamma-ray pulse height spectrometers. Three cases are considered: a conventional planar detector, a unipolar device, and a detector in which electronic signal processing has been applied to correct for charge trapping effects. We find that existing detectors are very limited in their maximum attainable active volume, but unipolar devices with charge correction show promise for producing large active volume devices.

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