Novel SiC Trench MOSFET with Improved Third-Quadrant Performance and Switching Speed

Area of Science:

• Power Electronics
• Semiconductor Devices
• Materials Science

Background:

• Silicon Carbide (SiC) MOSFETs are crucial for high-power and high-frequency applications.
• Existing designs face challenges with reverse conduction and switching losses.
• Optimizing device structure is key to overcoming these limitations.

Purpose of the Study:

• To propose and investigate a novel SiC double-trench MOSFET design.
• To improve reverse conduction characteristics and switching performance.
• To reduce parasitic capacitances for enhanced high-frequency operation.

Main Methods:

• Utilized 2-D device simulations to analyze the proposed SiC MOSFET.
• Compared the performance against standard double-trench MOSFET (DT-MOS) and DT-MOS with channel-MOS diode (DTC-MOS).
• Evaluated key parameters including forward voltage drop (V_F), blocking voltage (BV), oxide electric field (E_mox), gate-drain capacitance (C_gd), and gate-drain charge (Q_gd).

Main Results:

• The proposed MOSFET exhibited a lower V_F at high current densities (100 A/cm²), preventing bipolar degradation.
• Achieved a reduced maximum oxide electric field (E_mox) and lower gate-drain capacitance (C_gd) and charge (Q_gd).
• Despite a slightly higher specific on-resistance (R_on,sp), the device demonstrated significantly lower switching losses.

Conclusions:

• The novel SiC MOSFET design offers superior reverse conduction and switching performance.
• Reduced parasitic capacitances lead to significant advantages in high-frequency applications.
• This design presents a promising advancement for next-generation power electronic systems.