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FP7

SPEED Report Summary

Project ID: 604057
Funded under: FP7-NMP
Country: Spain

Periodic Report Summary 2 - SPEED (Silicon Carbide Power Technology for Energy Eficient Devices)

Project Context and Objectives:
The Call title was “Wide band-gap semiconductors for energy applications”.

The more promising (technically and economically) and studied wide band-gap semiconductors are SiC and GaN.

The material properties of SiC and GaN are superior to those of Si and will lead to better power devices with improved performance. However, today´s SiC and GaN power electronics perform rather poorly compared to the expectations, and production costs are far too high.

GaN seems a promising material for a certain range of applications, but this range seems to be restricted in voltage. A 1700 V GaN device is almost unthinkable. Even 600 V GaN devices seem to be far from achieving a minimum degree of repeatability and reliability. Given that the density of defect surfaces in GaN is orders of magnitude above those in SiC, an industrial implementation of a competitive GaN technology seems still far into the future.

In the meantime, high voltage (>1.7 kV) power electronics (PE) of competitive cost, high efficiency, and extreme reliability, are badly needed in order to enable progress towards a smart and sustainable power generation, transmission, and distribution network.

Silicon Carbide seems to be the perfect candidate to implement this much expected breakthrough in technology. There is little doubt that high-frequency, high temperature, and ultra-low loss power electronic devices are a necessary prerequisite for a Europe-wide penetration of renewable energies.

Achieving cost-competitiveness in SiC technology seems achievable in 4-5 years, and will - largely improve energy efficiency (at all levels);
- increase power quality;
- enable breakthrough new performance in energy distribution, such continuous voltage regulation, automated reactive power compensation and, in general terms, highly efficient automated distribution;
- create the conditions for a much larger penetration distributed energy resources such as local energy storage, home-scale photovoltaic generators, and plug-in electric vehicles.

Even more importantly, high-frequency, high temperature, and ultra-low loss power electronic devices will allow for a seamless integration of bidirectionality in the power grid, which means that energy may flow from the conventional generators to the conventional users, but also the other way round.

Thus, the development of a new generation of SiC-based high-voltage/high-power semiconductor devices, able to operate above 10kV, is crucial for turning the above-mentioned applications from an academic exercise into a cost-competitive and widely applied commercial reality.

Pooling world-leading manufacturers and researchers, SPEED aims at a achieving several breakthroughs in SiC technology, all along the whole supply chain:
• Highly improved and cost-efficient growth of SiC substrates and epitaxial-layers.
• Fabrication of power devices in the range from 1.700 V to above 10kV.
• Packaging and reliability testing of these devices.
• Demonstrating levels of reliability up to the highest standards. Promoting standardization and allowing for an objective and dispassionate evaluation of reliability.
• Developing SiC-based high-voltage/highly-efficient power conversion cells.
• Developing real-life applications and field-tests in close cooperation with two market-leading manufacturers of the new SiC-based high-voltage (HV) devices.
- A cost-efficient solid-state transformer to support advanced grid smartness and power quality.
- A wind turbine power converter with improved capabilities for generating AC and DC power.

Both already known and brand new methodologies will be adapted to SiC devices and optimized to make them a practical reality.

The main targets can be summarized in achieving are cost-savings, superior power quality, and extreme reliability, all of them in order to produce more efficient high-voltage/high-power converters that exploit the reduced power losses of SiC, its ability to work at much higher temperatures and frequencies (when compared with silicon).

At this point, after 2 years a half, the experience gained shows that the objectives set-up were very challenging. However, SPEED partners are achieving most of them, and when it is not possible, using contingency plans in order to achieve the global objective.

Project Results:
The activities performed to Work Packages 1, 2, 3, 4, 5, 6, 7 and 8. All Work Packages have started in Period 2.

WP1

The main work in P2 has been to improve the crystal growth process and to develop of 3rd generation of 100mm SiC wafers with improved structural quality. The demonstrated quality of the substrates are comparable or better than publically reported results from all mayor SiC material supplier.

Substrates with 3rd generation of 100 mm substrates’ has been used to produce epitaxial wafers. These has been processed to JBS diodes and characterised with good results.

For bipolar applications further improvements of the materials are required. This is specially the case for reduction of BPD using different buffer layers, and to improve the minority carrier lifetime optimising growth conditions or by using post-growth annealing techniques.

Work have been made in order to have epitaxy specification also included in the standard.

Most significant results WP1. The quality improvement of substrates which includes reduction of structural defects such as micropipes (MPD), threading screwdislocations (TSD), threading edge dislocations (TED) and basalplane dislocations (BPD).

WP2

The main results of the work performed in WP2 are: (i) Potential of hybrid modules for wind power solutions proven; (ii) JFET based 1700V modules developed and provided for electrical tests; (iii) MOSFET base technology defined and verified even under parallel connection; (iv) Proof of extendibility of the technology; (v) Design criteria for high voltage MPS diodes developed; (vi) Package concept developed and successfully demonstrated

WP3

The second lot of 3.3kV MOSFETs has been partially measured. Initial results on both test structures and large area chips show significant improvement over the first lot, with many devices showing good on-state and blocking performance.

In parallel to power MOSFET fabrication, SPEED partners are working on the optimization of novel gate dielectrics stacks, to improve the gate performances and reliability.

WP4

Initial reliability tests were conducted for the first reliability test report. test methodology and the electro-thermal characterisation. This characterisation equipment is available and showed excellent results on samples from other projects. The modelling activities stretched over the full period and cleared on time.

WP5

The gate driver for the semiconductors to be used has been designed. Two different topologies for DC/DC converters have been extracted for detailed investigations. The impact of SiC carbide devices in a wind Power Converter has being verified.

WP6

First steps on this WP have been done. The main work during this period has been oriented to study the different topologies to use in the demonstrator and the configuration of the SST.

WP7

Dissemination activities continue being a big pillar of the Project. More than 60 dissemination activities have been done. Everything goes according to the DoW.

WP8

Management has proceeded as expected and its main achievements have been:
- Improve communication between partners and within Consortium
- Overcome the changes within SPEED partners with relevant role in SPEED

Potential Impact:
Expected final results and their use, including economic and social impacts:
- Unipolar devices from 1700 up to above 10 kV
- Bipolar devices up to 6 kV
- Power modules constructed from the packaged devices
- Drivers and controls specially designed to drive SiC devices of such a high voltage and switching frequency
- Adaptation of packaging and passives to the high temperature operations that SiC can support
- Extreme reduction in size, weight, and cost of power converters due to reduction in the size of passive components (v.g. coils) and refrigeration requirements
- A completely novel generation of energy routers, misleadingly called “solid-state transformers”, whose introduction into the electricity distribution network will unable unseen and highly needed capacities such as automatic voltage regulation (adjustment to grid conditions), demand side management, automatic and continuous matching between supply and demand, distributed energy storage, continuous power factor correction, active/reactive power balance, fully automated operation modes, full communication capabilities with operation centers, higher penetration of distributed energy resources, higher penetration of renewable resources, and indirect transformation of non-dispatchable energy resources (renewable depending on weather conditions) into dispatchable energy resources (able to be “connected and disconnected” at will, thanks to the brand new storage capabilities that these systems will bring about.
Impacts that have been achieved so far are as follows:
(EI-i) Increasing the reliability and operational lifespan of components under realistic conditions;
(EI-ii) Considerable improvement of the operation of power-electronic devices
(EI-iii) Reducing size and weight, as well as Improving the cost effectiveness, of power converters;
Developing sustainable manufacturing concepts for 4” SiC substrates and epilayers.

List of Websites:
www.speed-fp7.org

Contact

Fernando Ubieta, (Project Advisor)
Tel.: +34 925233511
Fax: +34 925233901
E-mail
Record Number: 191997 / Last updated on: 2016-11-21
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