Vendor View - GTAT's Pure Play on Silicon Carbide Crystal
Figure 1 A portion of GTAT's production area at its Hudson, New Hampshire facility
Company Rapidly Increasing the Supply of SiC
Everywhere you look, the ‘electrification of everything’ is happening. Reliance on fossil fuels is, little by little, ebbing. While the shift is not a swift one, there is widespread agreement that ‘clean’ power is the direction the world is headed. Worldwide, more than 25 countries have announced a phase-out of internal combustion vehicles in the next few years as they invest in clean technology systems. In the United States, California, Massachusetts, and New Jersey are heading in the same direction.
It is against this backdrop that foundational developments are taking place at GT Advanced Technologies (GTAT). One of these is the emergence of advanced semiconductor materials and devices that can handle the kind of power needed to efficiently drive applications ranging from electric vehicles to massive data centers. Semiconductors have traditionally been built upon silicon wafers. Silicon chips make sense for mobile phones, watches, and televisions where cost and performance factors lend themselves to that material. But the electrification of cars, trucks, trains and other ‘power electronics’ applications (where voltages and currents exceed what silicon can efficiently handle) point to advanced semiconductor materials such as silicon carbide (SiC). First, it is extremely efficient with minimal losses and high switching speeds (transitioning from an ‘ON’ state to ‘OFF’). Second, chips made from SiC run at higher temperatures that enable minimal cooling requirements. Third, devices made from SiC can be smaller and therefore lighter. Using the electric vehicle as an example, SiC provides smaller and lighter powertrains, faster charging, and better range. Complementary to this, charging stations based on SiC technology will quicken the process to fully charge a vehicle.
GTAT’s role here is to make the SiC crystal that others downstream use to make wafers and devices. This is an important supply chain distinction because what the market demands is a rapidly growing supply of SiC crystal at affordable prices. “That is what the market is signaling,” says GTAT President and CEO Greg Knight. “There are many superb companies around the world that are very adept at wafering and device fabrication, and the goal is to put our CrystX® SiC at their doorstep at competitive prices and in high volume.” Over the past year, GTAT has signed long-term supply agreements with three of the largest global makers of wafers and devices.
Producing SiC is much more involved and challenging than making silicon crystal, and the material is not defect-free. While the technical benefits of SiC are well understood, producing the crystal in volume and at a cost and quality level that markets demand is challenging. “Our business model gives every company wishing to get into SiC a way to immediately do so,” said Knight. “They don’t need to invest in the capital and complex knowhow, because we’ve already done that.” The result is a much more rapid ‘path forward’ for SiC across growing markets that need the material. Wafer producers with strength in silicon can now offer SiC, which is a valuable portfolio position to have as applications transition from one material to the other.
Figure 2 As a 'pure play' producer of silicon carbide, GTAT is able to provide 'pucks' to downstream makers of wafers and semiconductors.
GTAT’s heritage as a crystal-growth equipment and technology provider puts it at a distinct advantage as demand accelerates for affordable SiC wafers. “There is a tremendous amount of knowhow we’ve brought to bear here,” said Knight. “We design equipment to enable the most robust and repeatable crystal growth process while minimizing capex and cost of ownership. We excel at building crystal-growth equipment and can scale very rapidly, and we have a strong and fundamental understanding of the science needed to drive material quality to the highest levels.”
Indeed, a mere 18 months after beginning production of CrystX® SiC, GTAT has achieved quality levels leading to long-term supply agreements with Global Wafers, ON Semiconductor and Infineon. “These are the companies that are highly invested in making the ‘electrification of everything’ a reality, and they are coming to us for their crystal material,” Knight said. GTAT produces its CrystX® SiC at 150mm diameter now and is driving toward 200mm to achieve a 1.8x increase in the number of devices that the larger surface area makes possible. GTAT’s quality levels are always being driven higher, which is the major focus point for the Company. One of the major benefits of GTATs overall process is the ability to deliver very precise resistivity values for its SiC. While the standard industry range of 19-22 Ω-cm for SiC is very attainable, GTAT meets customer specifications with the tightest distribution across the crystal.
Figure 3 A 150mm diameter CrystX® 'puck' ready for wafering
The deliverable from GTAT is a CrystX® SiC ‘puck’ that users slice into very thin wafers. The goal for customers is to achieve the highest amount of yield from each puck. In addition to transitioning from 150mm diameter to 200mm, usable height of the puck is also meaningful. GTAT is now producing the largest SiC pucks available in the market, with a roadmap that continually improves on that. This results in more wafers and more devices from a single puck.
Product quality levels are important, but an even more meaningful benchmark is GTAT’s overarching quality program that touches every aspect of the business. Here, GTAT is demonstrating a level of competence and speed unmatched in the industry. “We obtained ISO 9001:2015 certification very rapidly,” said Knight. “In less than a year, we equipped our facility, reached volume production, and achieved ISO certification. I cannot think of any other company in our industry that has been able to accomplish these milestones faster.” While the technical specifications for CrystX® SiC are industry-leading, customers are also very invested in seeing GTAT managed and operating in a quality-driven way.
In addition to ISO, IATF 16949 is a quality standard for the automotive industry. Since SiC is a fundamental part of the overall EV supply chain, GTAT is now meeting customer-driven requirements of this important global standard.
While the acceleration of the worldwide electric vehicle industry is a catalyst for GTATs growth, it is important to recognize that SiC is going to be useful in many other areas. One application area is renewable energy, where electricity requires additional power conversion before it can be fed to the grid. For example, a wind turbine produces electricity that must be converted from AC to DC, then back to AC for the grid. For solar energy, which produce DC power only, a SiC inverter turns power into alternating current the grid needs. The key to driving rapid adoption of all these applications is to grow the global supply of SiC and at affordable price points, which are the two focus points for the Company.
Figure 4 While the EV industry is the obvious driver for SiC adoption, several other application areas will call upon the material.
As wind- and solar-produced power sources form the basis for our global push toward renewable energy, managing that electricity becomes crucial. Energy storage systems help smooth the inevitable discrepancy between supply and demand, and these can be made smaller and easily scalable when using SiC-based modules and devices. Other applications for SiC are also increasing from industrial equipment and 5G telecom, where size and weight advantages of the material will match its electrical superiority.
The transition to renewable and clean energy sources is unquestionably accelerating, which means that efficient semiconductors designed to power this future are needed now. GTAT plays a vital role in this overall ecosystem by providing a high-volume supply of affordable SiC crystal upon which these advanced circuits are produced. As a ‘pure-play’ producer of SiC crystal, GTAT has forged a business model that is already proving advantageous on a worldwide scale.
To learn more about GTAT’s SiC capabilities, please visit www.gtat.com.
