SiC Power Devices – An Overview

2004 ◽  
Vol 815 ◽  
Author(s):  
Anant Agarwal ◽  
Mrinal Das ◽  
Sumithra Krishnaswami ◽  
John Palmour ◽  
James Richmond ◽  
...  
Keyword(s):  
Schottky Diodes ◽  
Gate Oxide ◽  
Current Gain ◽  
Power Devices ◽  
Forward Voltage ◽  
Pin Diodes ◽  
Power Mosfets ◽  
Voltage Instability ◽  
Igbt Modules ◽  
Near Future

ABSTRACTAn overview of SiC Power Devices is provided. Progress in 1200 V SiC Schottky diodes, 1200 V SiC BJTs, 10-20 kV SiC PiN diodes and 2 kV SiC Power MOSFETs will be described. SiC Schottky diodes have already been commercialized. The next step of inserting these diodes in Si IGBT modules is happening now. Emphasis is placed on the problems and issues at the SiC device/process interface which need to be urgently addressed such as the roughness created during the implant anneals, reliability of the gate oxide under positive and negative bias, low current gain of the BJTs, forward voltage instability in the pn junctions etc. Overcoming these issues in the near future will be critical to the successful commercialization of SiC devices.

A Case for High Temperature, High Voltage SiC Bipolar Devices

2007 ◽  
Vol 556-557 ◽  
pp. 687-692 ◽  
Author(s):  
Anant K. Agarwal
Keyword(s):  
High Temperature ◽  
High Voltage ◽  
Low Voltage ◽  
Schottky Diodes ◽  
Life Time ◽  
Extreme Environment ◽  
Junction Temperature ◽  
Current Gain ◽  
Pin Diodes ◽  
Bipolar Devices

The last three years have seen a rapid growth of 600 V and 1200 V SiC Schottky diodes primarily in the Power Factor Correction (PFC) circuits. The next logical step is introduction of a SiC MOSFET to not only further improve the power density and efficiency of the PFC circuits but also to enable the entry of all SiC power modules in Pulse Width Modulated (PWM) based power converters such as motor control in 600-1200 V range. The combination of SiC MOSFET and Schottky diodes will offer 60-80% lower losses in most low voltage applications at normal operating temperatures (< 200°C) where no significant improvements in packaging are required. This will cover most commercial applications with the exception of those having to function under extreme environment (>200°C) such as applications in automotive, aerospace and oil/gas exploration. For these high temperature applications, a case can be made for 600 - 2000 V Bipolar Junction Transistors (BJTs) and PiN diodes provided we do our homework on high temperature packaging. A number of interesting device related problems persist in bipolar devices such as forward voltage increase in PiN diodes and current gain degradation in BJTs. For very high voltage (>10 kV) applications such as those found in utilities (Transmission and Distribution), Large Drives and Traction, a case can be made for >10 kV PiN diodes, IGBTs, Thyristors and GTOs. While IGBTs will be restricted to <200°C junction temperature, the PiN diodes, Thyristors and GTOs may be operated at >250°C junction temperature provided that the high temperature, high voltage packaging issues are also addressed. Significant progress has been made in the development of the p-channel IGBTs and GTOs. The main issues seem to be the VF degradation due to stacking fault formation and improvement of minority carrier life-time.

4.5 kV-8 A SiC-Schottky Diodes / Si-IGBT Modules

2006 ◽  
Vol 527-529 ◽  
pp. 1163-1166 ◽  
Author(s):  
Dominique Tournier ◽  
Peter Waind ◽  
Phillippe Godignon ◽  
L. Coulbeck ◽  
José Millan ◽  
...  
Keyword(s):  
High Voltage ◽  
Bulk Material ◽  
Schottky Diodes ◽  
Power Devices ◽  
Large Area ◽  
Aerospace Applications ◽  
Dc Characteristics ◽  
Igbt Modules ◽  
Device Processing ◽  
Manufacturing Yield

Due to the significant achievements in SiC bulk material growth and in SiC device processing technology, this semiconductor has received a great interest for power devices, particularly for SiC high-voltage Schottky barrier rectifiers. The main difference to ultra fast Si pin diodes lies in the absence of reverse recovery charge in SiC SBDs. This paper reports on 4.5kV-8A SiC Schottky diodes / Si-IGBT modules. The Schottky termination design and the fabrication process gives a manufacturing yield of 40% for large area devices on standard starting material. Modules have been successfully assembled, containing Si-IGBTs and 4.5kV-SiC Schottky diodes and characterized in both static and dynamic regimes. The forward dc characteristics of the modules show an on-resistance of 33mohm.cm2 @ room temperatue (RT) and a very low reverse leakage current density (JR < 10 5A/cm2 @ 3.5kV). An experimental breakdown voltage higher than 4.7kV has been measured in the air on polyimide passivated devices. This value corresponds to a junction termination efficiency of at least 80% according to the epitaxial properties. These SiC SBDs are well suited for high voltage, medium current, high frequency switching aerospace applications, matching perfectly as freewheeling diodes with Si IGBTs.

Degradation of SiC High-Voltage pin Diodes

MRS Bulletin ◽  
2005 ◽  
Vol 30 (4) ◽  
pp. 305-307 ◽  
Author(s):  
Seoyong Ha ◽  
J. P. Bergman
Keyword(s):  
Basal Plane ◽  
Current Flow ◽  
Power Devices ◽  
Device Structure ◽  
Forward Voltage ◽  
Pin Diodes ◽  
Partial Dislocations ◽  
Nucleation Sites ◽  
Fundamental Understanding ◽  
Voltage Degradation

AbstractThe recent discovery of forward-voltage degradation in SiC pin diodes has created an obstacle to the successful commercialization of SiC bipolar power devices. Accordingly, it has attracted intense interest around the world. This article summarizes the progress in both the fundamental understanding of the problem and its elimination.The degradation is due to the formation of Shockley-type stacking faults in the drift layer, which occurs through glide of bounding partial dislocations. The faults gradually cover the diode area, impeding current flow. Since the minimization of stress in the device structure could not prevent this phenomenon, its driving force appears to be intrinsic to the material. Stable devices can be fabricated by eliminating the nucleation sites, namely, dissociated basal-plane dislocations in the drift layer.Their density can be reduced by the conversion of basal-plane dislocations propagating from the substrate into threading dislocations during homoepitaxy.

Influence of Shockley Stacking Fault Expansion and Contraction on the Electrical Behavior of 4H-SiC DMOSFETs and MPS diodes

2008 ◽  
Vol 1069 ◽  
Author(s):  
Joshua David Caldwell ◽  
Robert E Stahlbush ◽  
Eugene A. Imhoff ◽  
Orest J. Glembocki ◽  
Karl D. Hobart ◽  
...  
Keyword(s):  
Voltage Drop ◽  
Schottky Diodes ◽  
Stacking Fault ◽  
The Body ◽  
Electrical Behavior ◽  
Forward Voltage ◽  
Pin Diodes ◽  
Majority Carrier ◽  
Bipolar Devices ◽  
Forward Voltage Drop

ABSTRACTThe forward voltage drop (Vf) increase observed in 4H-SiC bipolar devices such as pin diodes due to recombination-induced Shockley stacking fault (SSF) creation and expansion has been widely discussed in the literature. It was long believed that the deleterious affect of these defects was limited to bipolar devices. However, it was recently reported that forward biasing of the body diode of a 10kV 4H-SiC DMOSFET led to similar Vf increases in the body diode I-V curve as well as a corresponding degradation in the majority carrier conduction characteristics as well and this degradation was believed to be due to the creation and expansion of SSFs during the body diode forward biasing. Here we report measurements comparing the influence of similar stressing, along with annealing and current-induced recovery experiments in DMOSFETs and merged pin-Schottky diodes with the previously reported results of these experiments in 4H-SiC pin diodes. The results of these experiments provide sufficient support that the observed degradation in the majority carrier conduction characteristics is the result of SSF expansion.

scholarly journals Investigation of the Impact of Neutron Irradiation on SiC Power MOSFETs lifetime by Reliability Tests

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5627
Author(s):  
Fabio Principato ◽  
Giuseppe Allegra ◽  
Corrado Cappello ◽  
Olivier Crepel ◽  
Nicola Nicosia ◽  
...  
Keyword(s):  
High Temperature ◽  
Neutron Irradiation ◽  
Neutron Fluence ◽  
Electrical Characterization ◽  
Gate Oxide ◽  
Power Devices ◽  
Electrical Parameters ◽  
Power Mosfets ◽  
The Impact ◽  
Dc Characterization

High temperature reverse-bias (HTRB), High temperature gate-bias (HTGB) tests and electrical DC characterization were performed on planar-SiC power MOSFETs which survived to accelerated neutron irradiation tests carried out at ChipIr-ISIS (Didcot, UK) facility, with terrestrial neutrons. The neutron test campaigns on the SiC power MOSFETs (manufactered by ST) were conducted on the same wafer lot devices by STMicroelectronics and Airbus, with different neutron tester systems. HTGB and HTRB tests, which characterise gate-oxide integrity and junction robustness, show no difference between the non irradiated devices and those which survived to the neutron irradiation tests, with neutron fluence up to 2× 1011 (n/cm2). Electrical characterization performed pre and post-irradiation on different part number of power devices (Si, SiC MOSFETs and IGBTs) which survived to neutron irradiation tests does not show alteration of the data-sheet electrical parameters due to neutron interaction with the device.

Methodology for Analysis of Schottky Diode Failures

2010 ◽  
Author(s):  
Bhanu P. Sood ◽  
Michael Pecht ◽  
John Miker ◽  
Tom Wanek
Keyword(s):  
Failure Mode ◽  
Schottky Diode ◽  
Failure Modes ◽  
Schottky Diodes ◽  
Failure Mechanisms ◽  
Forward Voltage ◽  
Fast Switching ◽  
Voltage Drops ◽  
The Common

Abstract Schottky diodes are semiconductor switching devices with low forward voltage drops and very fast switching speeds. This paper provides an overview of the common failure modes in Schottky diodes and corresponding failure mechanisms associated with each failure mode. Results of material level evaluation on diodes and packages as well as manufacturing and assembly processes are analyzed to identify a set of possible failure sites with associated failure modes, mechanisms, and causes. A case study is then presented to illustrate the application of a systematic FMMEA methodology to the analysis of a specific failure in a Schottky diode package.

Critical Technical Issues in High Voltage SiC Power Devices

2008 ◽  
Vol 600-603 ◽  
pp. 895-900 ◽  
Author(s):  
Anant K. Agarwal ◽  
Albert A. Burk ◽  
Robert Callanan ◽  
Craig Capell ◽  
Mrinal K. Das ◽  
...  
Keyword(s):  
Threshold Voltage ◽  
Carrier Mobility ◽  
Negative Charge ◽  
State Of The Art ◽  
Power Devices ◽  
Power Mosfets ◽  
Large Numbers ◽  
Technical Issues ◽  
The Difference ◽  
Difficult Issue

In this paper, we review the state of the art of SiC switches and the technical issues which remain. Specifically, we will review the progress and remaining challenges associated with SiC power MOSFETs and BJTs. The most difficult issue when fabricating MOSFETs has been an excessive variation in threshold voltage from batch to batch. This difficulty arises due to the fact that the threshold voltage is determined by the difference between two large numbers, namely, a large fixed oxide charge and a large negative charge in the interface traps. There may also be some significant charge captured in the bulk traps in SiC and SiO2. The effect of recombination-induced stacking faults (SFs) on majority carrier mobility has been confirmed with 10 kV Merged PN Schottky (MPS) diodes and MOSFETs. The same SFs have been found to be responsible for degradation of BJTs.

Exploration of heavy ion irradiation effects on gate oxide reliability in power MOSFETs

1995 ◽  
Vol 35 (3) ◽  
pp. 603-608 ◽  
Author(s):  
S.R. Anderson ◽  
R.D. Schrimpf ◽  
K.F. Galloway ◽  
J.L. Titus
Keyword(s):  
Ion Irradiation ◽  
Gate Oxide ◽  
Heavy Ion ◽  
Irradiation Effects ◽  
Power Mosfets ◽  
Heavy Ion Irradiation ◽  
Oxide Reliability

scholarly journals On the Lifetime Estimation of SiC Power MOSFETs for Motor Drive Applications

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 324
Author(s):  
Carmelo Barbagallo ◽  
Santi Agatino Rizzo ◽  
Giacomo Scelba ◽  
Giuseppe Scarcella ◽  
Mario Cacciato
Keyword(s):  
Electric Drive ◽  
Average Power ◽  
Estimation Procedure ◽  
General Purpose ◽  
Operating Conditions ◽  
Power Losses ◽  
Power Devices ◽  
Lifetime Estimation ◽  
Power Mosfets ◽  
Mission Profile

This work presents a step-by-step procedure to estimate the lifetime of discrete SiC power MOSFETs equipping three-phase inverters of electric drives. The stress of each power device when it is subjected to thermal jumps from a few degrees up to about 80 °C was analyzed, starting from the computation of the average power losses and the commitment of the electric drive. A customizable mission profile was considered where, by accounting the working conditions of the drive, the corresponding average power losses and junction temperatures of the SiC MOSFETs composing the inverter can be computed. The tool exploits the Coffin–Manson theory, rainflow counting, and Miner’s rule for the lifetime estimation of the semiconductor power devices. Different operating scenarios were investigated, underlying their impact on the lifetime of SiC MOSFETs devices. The lifetime estimation procedure was realized with the main goal of keeping limited computational efforts, while providing an effective evaluation of the thermal effects. The method enables us to set up any generic mission profile from the electric drive model. This gives us the possibility to compare several operating scenario of the drive and predict the worse operating conditions for power devices. Finally, although the lifetime estimation tool was applied to SiC power MOSFET devices for a general-purpose application, it can be extended to any type of power switch technology.

Mechanisms of Nitrogen Incorporation at 4H-SiC/SiO2 Interface during Nitric Oxide Passivation – A First Principles Study

2016 ◽  
Vol 858 ◽  
pp. 465-468 ◽  
Author(s):  
D.P. Ettisserry ◽  
Neil Goldsman ◽  
Akin Akturk ◽  
Aivars J. Lelis
Keyword(s):  
Nitric Oxide ◽  
Silicon Dioxide ◽  
First Principles ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Functional Theory ◽  
Power Mosfets ◽  
Voltage Instability ◽  
Nitrogen Incorporation ◽  
Effective Mobility

In this work, we investigate the behavior of Nitrogen atoms at 4H-Silicon Carbide (4H-SiC)/Silicon dioxide (SiO2) interface during nitric oxide passivation using ab-initio Density Functional Theory. Our calculations suggest different possible energetically favorable and competing mechanisms by which nitrogen atoms could a) incorporate themselves into the oxide, just above the 4H-SiC substrate, and b) substitute for carbon atoms at the 4H-SiC surface. We attribute the former process to cause increased threshold voltage instability (hole traps), and the latter to result in improved effective mobility through channel counter-doping, apart from removing interface traps in 4H-SiC power MOSFETs. These results support recent electrical and XPS measurements. Additionally, Nitric Oxide passivation is shown to energetically favor re-oxidation of the 4H-SiC surface accompanied by the generation of oxygen vacancies under the conditions considered in this work.

Sign in / Sign up

Export Citation Format

Share Document