Empowering electric vehicles with superior SiC
SmartSiC substrates hold the key to ramping volumes of better SiC devices for automotive and industrial applications.
BY EMMANUEL SABONNADIÈRE, CHRISTOPHE MALEVILLE AND CYRIL MENON FROM SOITEC
In September 2021, SmartSiC made its debut in Compound Semiconductor magazine. Pioneered by our company, Soitec, this novel material technology is a game-changer within the SiC industry: it is enabling a new generation of engineered substrates that consist of a thin layer of single-crystal SiC, bonded on a polycrystalline SiC wafer. Now two years on from this unveiling, SmartSiC is starting to fulfil its potential, delivering impressive results.
The impact of SmartSiC will be colossal. It has fundamentally changed perspectives for SiC, especially for 200 mm acceleration, and it is starting to reshape the SiC industry with a much greener technology. The great strengths of SmartSiC, compared with incumbent single-crystal SiC wafer, include an unparalleled ten-times hike in re-use capability and an eight-fold enhancement in electrical conductivity. Due to these massive improvements in key metrics, SmartSiC is opening new frontiers for high-performance SiC devices and their applications.
As well as these exceptional capabilities at the wafer level, SmartSiC is demonstrating its capability to produce a foundation that ensures better diodes and transistors. Measurements reveal a reduction in the drain-source on-resistance of 1200 V MOSFETs of between 10 percent and 15 percent, and around a 15 percent decrease in forward-voltage at a rated current in 650 V SiC diodes. These noteworthy improvements in device-level performance translate into a significant advantage in the fabs, with the opportunity for around a 25 percent increase in the number of high-quality die that can be produced from every 200 mm wafer for 25 mm² dies.
Leading the way, STMicroelectronics is the initial adopter of SmartSiC technology. Its collaboration with us has been dedicated to the rigorous automotive qualification of SmartSiC. The ultimate goal for our partnership is to qualify SmartSiC on ST SiC MOSFET technology in mid-2024, with products based on SmartSiC available from Q3 2024 onwards. Meeting this target will position both of us at the forefront of innovation in the EV sector.
Our SmartSiC technology continues to evolve and improve. Recently, we increased the crystal quality of our SmartSiC wafers with a specific epitaxy preparation, realised before the layer transfer of single-crystal SiC. Thanks to this advance, we have drastically reduced the basal plane dislocation density in our material. In turn, this will lead to better device performance.
This year, SmartSiC became a ‘must-have’ technology for key leaders in the SiC industry. With over a thousand prototypes under assessment and more than thirty prospects and clients, SmartSiC is now being adopted. High-volume production will take place at our new plant, Bernin4, which opened this September, following the installation of initial industrialisation lines over the summer months. When fully up and running, this fab will have a capacity of 500,000 wafers per year. Note that the production process used in this fab is flexible, starting with 150 mm wafers and adding 200 mm wafers in the first half of 2024. Once the ten-fold re-use goal is attained, another significant advantage will emerge: a secured production process, thanks to reserves of refreshed wafers that we will hold.
To put it succinctly, given all the strengths of SmartSiC, this technology is an obvious choice for any SiC device maker wanting to process 200 mm wafers – and that’s before considering current global scarcity of this material.
High-volume manufacturing
The unparalleled performance of SmartSiC is not just attracting the attention of makers of SiC power devices. Our technology is also garnering significant attention further along the supply chain, from Tier 1 and OEM companies within the automotive industry. What pleases them is that it will not be long before we attain IATF and ISO9001 certification at Bernin4, aligning with the standards of our other manufacturing plants in Bernin and Pasir-Ris. Note that our company, and our SmartSiC portfolio, are deeply committed to an impressive environmental, social and governance agenda.
High on our agenda when developing our production process is energy efficiency, with much effort directed at reducing energy consumption. Perfectly aligning with this objective, SmartSiC is starting to play a pivotal role in realising substantial reductions in carbon footprint when compared with traditional bulk SiC materials. Such a synergy is vital in supporting the ongoing EV revolution, which is making a crucial contribution to combating climate change. Our company, and SmartSiC, are actively aiding this cause at various levels, from wafer production to power device development and system integration.
Building Bernin4 has not been easy. As well as a supply crisis in construction materials, there’s been a flurry of industrial construction projects in the Grenoble region. Yet despite these issues, we have completed the 2000 m2 clean room for SmartSiC on time, with just 18 months elapsing from breaking ground to the construction of the first prototypes.