Silicon Carbide (SiC)-based devices are rapidly emerging as a transformative force in power electronics, with growing adoption across sectors such as automotive, photovoltaics (PV), energy storage, and uninterruptible power supplies (UPS). The paradigm shift from traditional silicon-based devices (IGBTs and MOSFETs) to SiC MOSFETs is largely driven by the superior figure-of-merit (FOM) of SiC materials, enabling higher efficiency, faster switching, and better thermal performance.
For decades, planar MOSFETs have been the mainstream choice for discrete SiC power devices due to their simplified structure, mature fabrication processes and proven reliability. As SiC process technology has advanced, the specific on-resistance (Ron,sp = Ron × A) has been continuously reduced by shrinking the cell pitch, thereby increasing the number of effective cells within a fixed die area. Today, commercial SiC MOSFETs feature cell pitches below 4.0 µm, approaching the scaling limits of planar MOS structures due to: intrinsic JFET resistance and difficulty of feature size scaling. The industry now faces a critical decision point: Continue pushing the limits of planar MOSFETs, or transition to trench MOSFET architectures. While trench MOSFETs introduce challenges such as: Elevated electric fields at the trench bottom, raising reliability concerns and more complex process integration. They also offer compelling advantages: higher channel mobility and reduced JFET resistance. These benefits make trench MOSFETs an attractive successor from the perspective of planar MOSFET manufacturers seeking performance gains.

In this presentation, we will review the evolution of SiC MOSFET technology, highlighting:

• Technological advancements in planar MOSFETs
• Emerging perspectives on trench MOSFET architectures
• Insights from ongoing R&D activities at Hunan Sanan Semiconductor, aimed at overcoming scaling barriers and unlocking the next generation of high-performance SiC power devices.