Page 30 - PEN eBook July 2022

Design SEMICONDUCTORS

in the Vienna rectifier front end, while devices with 42-mΩ R are employed in the DAB stages.
DS(on)

The DAB stages run between 140 and 400 kHz and achieve zero-voltage switching in most of their

operation points.

The entire system achieves a power density of 10 kW/l or 163 W/in. , respectively, at a peak efficiency
3
of above 95%.

Non-CMOS-Compatible

SiC Power Device

Fabrication in Volume

Si Fabs

Adapted from a presentation by Victor Veliadis, executive director and CTO of
PowerAmerica and professor of electrical and computer engineering at North
Figure 3: 10-kW EV charging unit supporting a wide output voltage range and a Carolina State University
power density of 10 kW/l (163 W/in. )
3
Silicon carbide devices are displacing their incumbent silicon counterparts in several
(Note: The authors would like to thank Professor Johann Kolar, Yunni Li, and Michael Haider from high-volume power applications. As SiC market share continues to grow, the industry is lifting

the Power Electronic Systems Laboratory at ETH Zurich for their ongoing cooperation on the EV the last barriers to mass commercialization that include higher-than-Si-device cost, relative lack
charging unit). of wafer planarity, the presence of basal plane dislocations, reliability and ruggedness concerns,
and the need for a workforce skilled in SiC power technology to keep up with the rising demand.
To enable cost-effective SiC manufacturing, high-yielding fabrication processes are required. In
my PowerUP presentation, I will summarize key aspects of SiC fabrication technology and outline
non-CMOS-compatible processes that have been streamlined to allow for mass SiC device
Reference fabrication in conventional mature Si fabs.

SiC WAFERS

▶ PowerUP Expo 2022 Today, the SiC wafer represents 55% to 70% of the overall SiC device cost, a consequence of its
uniquely complex fabrication specifics. Conventional SiC substrates are primarily grown by the seeded
sublimation technique at temperatures of ~2,500˚C, which creates process control challenges. Crystal

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