Page 119 - NEW Armstrong Book - 2

T
he importance of sili- con carbide in markets such as e-mobility and
charging stations, data centers, wind and solar generators, etc.); and 5G communications (mobile phones and base sta- tions, which include both SiC devices and high-speed GaN- on-SiC devices).
Why silicon carbide?
SiC, a semiconductor compound consisting of silicon and carbon, belongs to the wide-bandgap family of materials. Its physical bond is very strong, giving the semiconductor a high mechanical, chemical, and thermal stability. SiC’s wide band- gap and high thermal stability allow SiC devices to be used at junction temperatures higher than silicon equivalents, even over 200˚C. The main advantage offered by SiC in power applications is its low drift region resistance, which is a key factor for high-voltage power devices.
As the industry continues to grow, there will be an increasing demand for wafer reclaim, as well as process optimization.
SiC wafer fabrication is a delicate process. Not all wafers are ideal for final solutions such as diodes and MOSFETs. Rhoades pointed out that the wafer reclaim process offered by X-Trinsic can have a role in this regard. “If a device manufac- turer or engineering team has a batch of wafers that they’ve used for engineering tests and can’t be used for devices, you can reclaim them by removing any damaged surface layer and then repolishing to restore a device-ready surface at a much lower cost than buying a new wafer,” he said.
What’s more, as the industry continues to grow and more wafers are processed by more companies, there will be an increasing demand for wafer reclaim, as well as process opti- mization. Silicon technology is different from SiC technology, so processes that work well for silicon will almost certainly have to be redeveloped for SiC. The test and fabrication tech-
Improving the SiC Wafer Process
new energy has prompted many
companies to review and invest
in wafer technology to define
development plans in line with
the demand. X-Trinsic is a com-
pany that aims to improve the
manufacturing process and
focuses on accelerating the
adoption of SiC-based products.
X-Trinsic was founded by Dennis Ricco, CEO and EVP of cus- tomer operations, and Robert Rhoades, president and CTO, with the explicit purpose of providing services focused on the SiC market. These services fall into three categories:
1. Wafering (all process steps to transform a solid puck of SiC into epi-ready or device-ready prime wafers)
2. SiC wafer reclaim to restore certain engineering or off- spec wafers to a usable state
3. Technical or business consulting on a wide range of topics
In an interview with Power Electronics News, Rhoades noted the steps of fabrication for SiC wafers and the importance of solid background knowledge for those working in this field, concerning not only electrical engineering but also materi- als science. “It’s critical to have a good, diverse team with the goal of understanding the properties of the material and how to design devices and circuits — and then systems — to be built with this unique material,” he said. “You need people who understand how to develop modules and systems and assemblies leveraging the properties of silicon carbide and the device’s characteristics in the best way at the system level. It’s very useful for engineers and technologists to have a broad perspective to understand the whole technology.”
SiC demand is rapidly growing in three major markets: dis- crete power devices for energy efficiency (MOSFETs and diodes); power inverters and regulators (in electric vehicles,
By Maurizio Di Paolo Emilio
X-TRINSIC’SROBERTRHOADES
105