SiC MOSFET Explained: Working Principle, Advantages, Applications & Future Trends

The development of modern technology is powered by components like electric vehicles and renewable energy. These components rely on modern technology like consumer electronics and industrial machinery. More advanced semiconductor technology is challenging silicon-based power devices as industries increasingly demand high efficiency, high power density, and greater reliability. Silicon Carbide MOSFETs are among the most relevant improvements in this technology. 

Silicon Carbide devices have been designed to replace conventional Silicon-based power devices. These devices have even greater efficiencies and the ability to switch and operate at a lower and higher temperature. Because of this, these devices have been designed to be used in even better power conversion systems than have previously been made. 

What is a SiC MOSFET?

Silicon Carbide MOSFETs are a type of power semiconductor that uses silicon carbide as its primary semiconductor. Controlling the current of these devices is the same as controlling conventional MOSFETs by applying a voltage to the gate. However, the switching speed, the operating temperature, and the voltage capabilities are greatly enhanced with the use of Silicon Carbide. Because Silicon Carbide is a wide-bandgap semiconductor, it is able to better withstand higher temperatures and electric fields than silicon. This is why silicon is ideal for more demanding applications of power. 

Understanding Silicon Carbide Technology

Silicon Carbide is a compound semiconductor of silicon and carbon. With its inherent physical and electrical characteristics, it is positioned as one of the leading next-generation power electronics. 

Silicon carbide has several distinctive properties:

  • Higher Breakdown Voltage

  • Higher Thermal Conductivities

  • Lower Switching Losses

  • Energy efficient

  • Capable of High Temperatures

The features are beneficial for developing a new generation of more compact and lighter computing power.

SiC MOSFET Principles

A SiC MOSFET works similarly to a traditional MOSFET

OFF State

Without the proper voltage at the gate, the device is conducting, and current cannot flow from the source to the drain. 

ON State

If the gate voltage is above threshold and positive, current can then flow from the source to the drain, as a conductive channel is formed.

Fast Switching

A large advantage of SiC MOSFET is the rapid switching between on and off, as this not only saves energy but also makes the system run more efficiently.

Advantages or Benefits of SiC MOSFETs

  • Improved Efficiency: SiC MOSFETs have a significant reduction in conduction and switching losses. This results in a more efficient design overall.

  • High Switching Speed: The rapid switching capability allows for a more compact system design.

  • Operation at High Temperatures: SiC MOSFETs function well in the high temperatures of many industrial environments.

  • Less Cooling Demand: Less heat is generated, resulting in less need for a cooling system.

  • Higher Voltage Capability: These devices provide excellent high-voltage performance and reliability.

  • Compact System Design: SiC MOSFETs allow for lighter and smaller systems.

Disadvantages or Drawbacks of Sic MosFets

  • High Price: The cost of SiC MOSFETs is higher than that of conventional silicon devices.

  • Special Gate Drivers: SiC MOSFETs may require special gate drivers.

  • Design Problems: Careful design is needed to limit the EMI and voltage transients.

Application of Sic MOSFETs

  • Industrial Power Supplies: SiC MOSFETs are used for Power Conversion in industrial automation equipment.

  • Renewable Energy: SiC MOSFETs are used in solar and wind energy converters for optimal energy output.

  • Aerospace and Defence: SiC MOSFETs are used in high-temperature and critical systems in Aerospace and Defence.

  • Electric Vehicles: SiC MOSFETs are used in the inverters and chargers of Electric Vehicles to improve efficiency, increase range, and decrease weight. Renewable Energy: SiC MOSFETs are used in solar and wind energy converters for optimal energy output.