Optimising the Rectification Ratio of Schottky Diodes in n-SiC and n-Si by TCAD

MRS Advances ◽  
2016 ◽  
Vol 1 (54) ◽  
pp. 3655-3660
Author(s):  
Hiep N. Tran ◽  
Tuan A. Bui ◽  
Geoff K. Reeves ◽  
Patrick W. Leech ◽  
Jim G. Partridge ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Finite Element Modelling ◽  
Room Temperature ◽  
Schottky Diodes ◽  
State Density ◽  
Insulating Layer ◽  
Forward Current ◽  
Current Voltage ◽  
A Minor ◽  
Aided Design

ABSTRACT Finite element modelling has been used to optimise the current/ voltage (I/V) characteristics of metal/ n-SiC and metal/ n-Si diodes incorporating a thin interfacial layer. The electrical properties of the diodes have been examined in relation to the polytype of SiC (3H, 4H or 6C), the doping level, NA, (1015 - 1018cm3) of the substrate, the defect state density, Dit and the work function of the Schottky metal, Φm. The modelling by Technology Computer-Aided Design (TCAD) has shown that the presence of an interfacial insulating layer with a thickness of 1.0 nm has reduced the reverse leakage current of the diode by a factor of ∼102 in Si and 1013 (from 10-19 A to 10-6 A) for SiC with only a minor reduction (∼ 0.8 times) in the forward current in SiC. The properties of the diodes have been modelled at room temperature without thermal annealing.

Demonstration of 13-kV Class Junction Barrier Schottky Diodes in 4H-SiC with Three-Zone Junction Termination Extension

2017 ◽  
Vol 897 ◽  
pp. 451-454 ◽  
Author(s):  
Hidenori Kitai ◽  
Yasuo Hozumi ◽  
Hiromu Shiomi ◽  
Masaki Furumai ◽  
Kazuhiko Omote ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Schottky Diodes ◽  
Pin Diode ◽  
Current Waveform ◽  
Forward Voltage ◽  
Sharp Drop ◽  
Forward Current ◽  
Blocking Voltage ◽  
Aided Design ◽  
Breakdown Model

The static and dynamic characteristics of 13-kV class 4H-SiC junction barrier Schottky (JBS) diodes with a three-zone junction termination extension (JTE) are presented. Using an anisotropy breakdown model, technology computer-aided design simulation of devices with a three-zone JTE agrees well with the obtained experimental results, correctly predicting a sharp drop in blocking voltage at high JTE acceptor concentrations. The forward voltage of the JBS diode at 75°C and a forward current of 500 mA is reduced to approximately one-ninth by that of 13 series-connected 1000-V Si PiN diodes. This suggests that conduction losses of traditional high-voltage circuits which conventionally use series-connected devices can be drastically reduced by replacing the series-connected devices with a single 13-kV class SiC JBS diode. Moreover, the reverse recovery current waveform of the 13-kV class SiC JBS diode shows that these diodes have lower reverse recovery losses than a 13-kV SiC PiN diode.

Study on Schottky Diode Characteristics Improving by X-Ray Irradiation

2013 ◽  
Vol 717 ◽  
pp. 113-116
Author(s):  
Sani Klinsanit ◽  
Itsara Srithanachai ◽  
Surada Ueamanapong ◽  
Sunya Khunkhao ◽  
Budsara Nararug ◽  
...  
Keyword(s):  
Leakage Current ◽  
Schottky Diode ◽  
Room Temperature ◽  
The Other ◽  
Low Power Consumption ◽  
Initial Value ◽  
X Ray ◽  
Forward Current ◽  
Current Voltage ◽  
Current Voltage Characteristics

The effect of soft X-ray irradiation to the Schottky diode properties was analyzed in this paper. The built-in voltage, leakage current, and work function of Schottky diode were investigated. The current-voltage characteristics of the Schottky diode are measured at room temperature. After irradiation at 70 keV for 55 seconds the forward current and leakage current are increase slightly. On the other hand, the built-in voltage is decrease from the initial value about 0.12 V. Consequently, this method can cause the Schottky diode has low power consumption. The results show that soft X-ray can improve the characteristics of Schottky diode.

Effect of series resistance on the forward current-voltage characteristics of Schottky diodes in the presence of interfacial layer

1996 ◽  
Vol 39 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Enise Ayyildiz ◽  
Abdulmecit Türüt ◽  
Hasan Efeoğlu ◽  
Sebahattin Tüzemen ◽  
Mustafa Sağlam ◽  
...  
Keyword(s):  
Interfacial Layer ◽  
Series Resistance ◽  
Schottky Diodes ◽  
Forward Current ◽  
Current Voltage ◽  
Current Voltage Characteristics

Anomalous Scatter of Forward Current-Voltage Characteristics of He+-Irradiated Ni/4H-SiC Schottky Diodes

2016 ◽  
Vol 858 ◽  
pp. 749-752 ◽  
Author(s):  
Anatoly M. Strel'chuk ◽  
Viktor V. Zelenin ◽  
Alexei N. Kuznetsov ◽  
Joseph Tringe ◽  
Albert V. Davydov ◽  
...  
Keyword(s):  
Series Resistance ◽  
Degradation Mechanism ◽  
Schottky Diodes ◽  
Defect Structures ◽  
Induced Current ◽  
Forward Current ◽  
Current Voltage ◽  
Before And After ◽  
Current Voltage Characteristics

A study of forward current-voltage characteristics of Ni/4H-SiC Schottky diodes (SDs) before and after irradiation with He+ ions revealed features that characterize defect structures and reveal the degradation mechanism of the diodes. These features are the presence of excess currents of certain type in the unirradiated SDs, their appearance in forward-biased originally ideal SDs, and a >10 orders of magnitude scatter of the series resistance of the SDs upon their irradiation with He+ ions. A model of localized defect-induced current paths (shunts) in the form of unintentionally produced SDs with the substrate is suggested.

scholarly journals Device Design Assessment of GaN Merged P-i-N Schottky Diodes

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1550 ◽  
Author(s):  
Yuliang Zhang ◽  
Xing Lu ◽  
Xinbo Zou
Keyword(s):  
Breakdown Voltage ◽  
Computer Aided Design ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Background Concentration ◽  
Model Parameters ◽  
Design Assessment ◽  
Blocking Voltage ◽  
Aided Design ◽  
Drift Layer

Device characteristics of GaN merged P-i-N Schottky (MPS) diodes were evaluated and studied via two-dimensional technology computer-aided design (TCAD) after calibrating model parameters and critical electrical fields with experimental proven results. The device’s physical dimensions and drift layer concentration were varied to study their influence on the device’s performance. Extending the inter-p-GaN region distance or the Schottky contact portion could enhance the forward conduction capability; however, this leads to compromised electrical field screening effects from neighboring PN junctions, as well as reduced breakdown voltage. By reducing the drift layer background concentration, a higher breakdown voltage was expected for MPSs, as a larger portion of the drift layer itself could be depleted for sustaining vertical reverse voltage. However, lowering the drift layer concentration would also result in a reduction in forward conduction capability. The method and results of this study provide a guideline for designing MPS diodes with target blocking voltage and forward conduction at a low bias.

Schottky Barriers on p-GaN

1995 ◽  
Vol 395 ◽  
Author(s):  
N.I. Kuznetsov ◽  
E.V. Kalinina ◽  
V.A. Soloviev ◽  
V.A. Dmitriev
Keyword(s):  
Room Temperature ◽  
Current Flow ◽  
Thermal Evaporation ◽  
Chemical Vapor ◽  
Schottky Barriers ◽  
Flow Mechanism ◽  
Vacuum Thermal Evaporation ◽  
Forward Current ◽  
Current Voltage ◽  
Capacitance Voltage

ABSTRACTSchottky barriers were formed on p-GaN. p-GaN layers doped with Mg were grown by metalorganic chemical vapor deposition (MOCVD). 6H-SiC wafers were used as substrates. The barriers were made by vacuum thermal evaporation of Au. Capacitance-voltage (C-V) and current-voltage (I-V) characteristics of the barriers were investigated. The concentration of the ionized acceptors in the p-layers was measured to be about ∼1017 cm−3. The barrier height was determined to be 2.48 eV by C - V measurements at room temperature. The forward current flow mechanism through the barriers is discussed.

High Voltage Schottky Barrier Diodes on P-Type SiC using Metal-Overlap on a Thick Oxide Layer as Edge Termination

1999 ◽  
Vol 572 ◽  
Author(s):  
Q. Zhang ◽  
V. Madangarli ◽  
S. Soloviev ◽  
T. S. Sudarshan
Keyword(s):  
Schottky Barrier ◽  
Oxide Layer ◽  
Breakdown Voltage ◽  
Schottky Diodes ◽  
Schottky Barrier Diodes ◽  
Edge Termination ◽  
Forward Current ◽  
Current Voltage ◽  
Thick Oxide Layer ◽  
P Type

ABSTRACTP-type 6H SiC Schottky barrier diodes with good rectifying characteristics upto breakdown voltage as high as 1000V have been successfully fabricated using metal-overlap over a thick oxide layer (∼ 6000 Å) as edge termination and Al as the barrier metal. The influence of the oxide layer edge termination in improving the reverse breakdown voltage as well as the forward current – voltage characteristics is presented. The terminated Schottky diodes indicate a factor of two higher breakdown voltage and 2–3 times larger forward current densities than those without edge termination. The specific series resistance of the unterminated diodes was ∼228 mΩ-cm2, while that of the terminated diodes was ∼84 mΩ-cm2.

The Properties of n-ZnO/p-SiC Heterojunctions and their Potential Applications for Devices

2006 ◽  
Vol 527-529 ◽  
pp. 1571-1574 ◽  
Author(s):  
Cole W. Litton ◽  
Ya.I. Alivov ◽  
D. Johnstone ◽  
Ümit Özgür ◽  
V. Avrutin ◽  
...  
Keyword(s):  
Room Temperature ◽  
Molecular Beam ◽  
Reverse Bias ◽  
Zno Films ◽  
Turn On ◽  
Forward Current ◽  
Current Voltage ◽  
Potential Applications ◽  
Current Voltage Characteristics ◽  
P Type

Heteroepitaxial n-ZnO films have been grown on commercial p-type 6H-SiC substrates by plasma-assisted molecular-beam epitaxy, and n-ZnO/p-SiC heterojunction mesa structures have been fabricated and their photoresponse properties have been studied. Current-voltage characteristics of the structures had a very good rectifying diode-like behavior with a leakage current less than 2 x 10-4 A/cm2 at -10 V, a breakdown voltage greater than 20 V, a forward turn on voltage of ∼5 V, and a forward current of ∼2 A/cm2 at 8 V. Photosensitivity of the diodes, when illuminated from ZnO side, was studied at room temperature and photoresponsivity of as high as 0.045 A/W at -7.5 V reverse bias was observed for photon energies higher than 3.0 eV.

scholarly journals Impression material accuracy for palatal orthodontic miniscrews

2020 ◽  
Vol 81 (6) ◽  
pp. 427-439
Author(s):  
Natalie Schenz ◽  
Vincent Schwarz ◽  
Romed Hörmann ◽  
Adriano G. Crismani
Keyword(s):  
Computer Aided Design ◽  
Setting Time ◽  
Cost Effective ◽  
Minor Effect ◽  
Standard Type ◽  
Type Iv ◽  
Impression Materials ◽  
Observer Experience ◽  
A Minor ◽  
Aided Design

Abstract Purpose This study investigates the accuracy of abutment transfer with current impression materials and provides a concise overview, including other relevant factors, in order to enable clinicians to make an informed decision about the optimal impression for this treatment procedure. Methods In all, 96 impressions of a cadaver head with two orthodontic miniscrews in place were taken with four common impression materials by two observers and using two methods of application. After pouring with a standard type IV stone and abutment transfer, all models and the upper jaw (which had been separated from the head) were scanned in a standard model scanner (Zirkonzahn® [Zirkohnzahn GmbH, Gais, Italy] S600 ARTI) and evaluated using a computer-aided design (CAD) program (GOM-Inspect [Gesellschaft für optische Messtechnik m.b.H., Braunschweig, Germany]). The deviations were measured at six points per screw and statistically evaluated with SPSS® (IBM, Chicago, IL, USA). Results Optimal values were obtained with biphasic polyvinylsiloxane, while monophasic polyvinylsiloxane, alginate and polyether also resulted in acceptable accuracy. Observer experience showed no effect and the method of application had only a minor effect on accuracy. Conclusions Within the limitations of this study, it seems that all impression materials are suitable for miniscrew abutment transfer, provided that methods of intraoral adaptation of the orthodontic appliance can be employed. If higher accuracy is needed or for clinicians with less experienced, a biphasic polyvinylsiloxane impression with the putty-wash technique should be used as this combination reduces setting time. The most cost-effective version, alginate, can be used if the consequences of greater deviations can be handled. Caution is advised with polyether if undercuts are present.

New Computer Aided Design, Finite Element Modelling and Three-Dimensional Measuring of Rear Screen Creep Forming

1995 ◽  
Vol 209 (2) ◽  
pp. 137-143 ◽  
Author(s):  
D Lochegnies ◽  
E François ◽  
J Oudin
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Computer Aided Design ◽  
Finite Element Modelling ◽  
Three Dimensional ◽  
Finite Element Models ◽  
Element Modelling ◽  
Computer Aided ◽  
Analysis Strategy ◽  
Aided Design

A new analysis strategy for creep forming by coupling computer aided design (CAD), finite element models (FEM) and three-dimensional measuring (3D M) with two new CAD/FEM and CAD/3D M interfaces. From the design product via Bézier curves, the manufacturer is now able to predict and adjust creep forming database (initial form of the sheet, geometry of the skeleton, temperature map in the sheet at the furnace exit and forming time) through CAD and FE modules. A reference rear screen manufacture is optimized using the previous strategy and validated with the experimental data through CAD and 3D M modules.

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