Electric vehicle go-slow hits SiC power devices

May 07, 2013 // By Sandrine Leroy
Wide-bandgap transistor and diode growth potential is obscured by automotive qualification, explains Yole Développement's Philippe Roussel, though PV inverter growth is a bright spot.

Uncertainty hangs over the market for power devices made with wide-bandgap semiconductor SiC, due to a lack of clarity over whether and when electric vehicles will adopt them.

“We have no firm estimate of when it will come,” said Philippe Roussel, business unit manager compound semiconductors, power electronics, LED & photovoltaics at market analysts Yole Développement in Lyon, France. “It’s still questionable.”

Automotive qualification can take up to five years, Roussel pointed out. So even if qualification for use in electric and hybrid electric vehicles (EV/HEV) is on-going it likely won’t be clear if SiC has been successful until 2015. And though qualification for EV/HEV charger inverters would be quicker, SiC faces a greater challenge there from silicon superjunction MOSFETs, IGBTs, and also wide-bandgap GaN devices.

As a result, when Yole releases its latest analysis on the SiC industry on May 8, it will describe two scenarios for SiC industry evolution. Its more optimistic scenario will see SiC devices used commercially in EV/HEV from 2015 onwards, taking 11% of the market from silicon IGBT devices by 2020. In the pessimistic scenario EV/HEV implementation doesn’t start until 2017/2018, making PV inverters the number one SiC application in 2020.

Today there remains much room for increasing SiC device usage in PV inverter applications, Roussel underlined. “Each inverter manufacturer’s product line-up has just one or two models with SiC in them, among dozens,” he said. “But it’s a very positive starting point.” That helped SiC power device industry revenues to $76 million in 2012, including R&D but excluding military use. PV inverter producers are the second industry to broadly adopt SiC devices, after manufacturers using SiC for power factor correction in high-end server power supplies.

Some PV inverter manufacturers use a SiC diode and silicon IGBT or MOSFET, and some offer full SiC inverters. “They’re just the first attempt, as inverter makers have limited their SiC development investment,” Roussel said. “They’re doing a