With the growing need of more advanced chips and designs, SiC power semiconductor segment is commendable. According to a report, the silicon carbide (SiC) power semiconductor market is increasing at a compound annual growth rate (CAGR) of 29% from 2017 to $1.4bn in 2023.
The report noted that the SiC market is still being driven by diodes used in power factor correction (PFC) and photovoltaic (PV) applications.
However, Yole expects that in five years the main SiC device market driver will be transistors, with a 50% CAGR over 2017-2023.
The improvement is said to be because of transistor performance and reliability compared with the first generation of products.
Yole says that atopic that has been discussed in all its exchanges with industrial players is SiC adoption for automotive applications over the next 5-10 years. “Its implementation rate differs depending on where SiC is being used,” comments Dr Hong Lin, Technology and Market Analyst, Compound Semiconductors at Yole. “That could be in the main inverter, in the on-board charger (OBC) or in the DC/DC converter,” he adds. “More than 20 automotive companies are already using SiC Schottky barrier diodes (SBDs) or SiC metal-oxide semiconductor field-effect transistors (MOSFETs) for the OBC, which will lead to a 44% CAGR through to 2023.”
Yole anticipates SiC adoption in the main inverter by some pioneers, at a 108% CAGR during 2017-2023, since nearly all carmakers have projects to implement SiC in the main inverter over coming years. Chinese automotive players in particular are strongly considering the adoption of SiC.
An example of early adoption is the recent SiC module developed by STMicroelectronics for Tesla and its Model 3 car. The SiC-based inverter, analyzed by Yole’s sister company System Plus Consulting, consists of 24 1-in-1 power modules. Each contains two SiC MOSFETs with an innovative die attach solution and connected directly on the terminals with copper clips and thermally dissipated by copper baseplates. The thermal dissipation of the modules is enabled by a specially designed pin-fin heatsink.
“The SiC MOSFET is manufactured with the latest STMicroelectronics technology design,” notes Dr Elena Barbarini, head of Department Devices at System Plus Consulting. “This technical choice allows a reduction of conduction losses and switching losses,” she adds. STMicroelectronics is strongly involved in the development of SiC-based modules for the automotive industry. During its recent Capital Markets Day, the leading player detailed its activities in this field. STMicroelectronics is also commited to the development of innovative packaging solutions.
In general, system manufacturers are interested in implementing cost-effective systems that are reliable, regardless of whether the power devices are silicon or SiC based. “Today, even if it’s certified that SiC performs better than silicon, system manufacturers still get questions about long-term reliability and the total cost of the SiC inverter,” comments Ana Villamor, technology & market analyst, Power Electronics & Compound Semiconductors at Yole.
Is Supply chain ready for SiC?
Matching the supply chain with the evolving SiC market can be a snag. One of the bottlenecks as of 2018 is SiC wafer supply.
The shortage has existed since late 2016. Yole says that last year it heard complaints. Some expected the situation to be resolved in second-half 2017, but as of mid-2018 the issue remains, due to two main reasons:
(1) the transition from 4” to 6” wafers is much faster than suppliers expected;
(2) the increase in wafer demand has been faster than expected.
Some say that the shortage is temporary and typical when shifting to larger wafer sizes. Others consider the situation to be critical. It is a good problem for wafer suppliers, as constrained supply allows them to maintain high wafer prices. But they are also investing heavily to satisfy demand from numerous clients. Yole estimates that, in the coming years, several hundred million dollars will be invested, as leading SiC wafer suppliers Cree-Wolfspeed, II-VI Inc and Dow are all planning to expand capacity.
At the epiwafer level, the market has struggled to take off for several years, but the situation is evolving quickly. For example, Yole has seen Showa Denko expand its capacity consecutively in 2015, 2016 and 2018 as the technology becomes more mature and the outsourcing ratio increases.
markets. This strategy pivot will allow Cree to invest more into its SiC activities (expanding wafer, epiwafer and device capacity) and prepare for market growth. On the other side of the abortive acquisition, Infineon has also developed its SiC power business. The firm signed a long-term SiC wafer supply agreement with Cree and began to actively promote its CoolSiC MOSFETs at different power electronic tradeshows and conferences in 2018.
A foundry model is clearly forming that enables fabless and fab-lite companies to launch SiC products and make the technology more accessible. However, there was also a short supply of foundry services in 2017. The new 6” wafer foundry Clas-SiC Wafer Fab Ltd was founded in 2017 comprising the entire SiC team from Raytheon, which has ceased its SiC activities. Taiwanese foundry Episil is also now active.
The report was commissoned by ‘Power SiC 2018: Materials, Devices and Applications’ by the Power & Wireless team at market research and strategy consulting company Yole Développement.