Increasing the Efficiency through Wide-Bandgap Semiconductors (SiC & GaN)

Efficiency has a prominent place in the electronics industry as it decides the performance and service life of devices. High efficiency means the requirement of devices with a higher power density with a vision of compact, lighter, and more reliable products in data centers and the automotive industry.

In recent times, complexity is increasing in the devices due to the involvement of a huge number of components, which in turn invokes the need for more efficient power conversion. If devices are more efficient then it will reduce the cost of power input to the components and the environmental impact would be less. Reduction in losses simply means more efficient and high-performance devices. Power conversions lead to device power losses in terms of heat dissipation hence making the system less efficient. And this undesired power loss from electronic equipment is toxic to the environment. These drawbacks led to an increase in research and the development of more advanced semiconductor devices.

WBG Semiconductors integration in transistors

The market is now switching from silicon to wide band gap semiconductor materials that can operate at high voltages which can generate more power. In addition, these materials have different crystalline characteristics which make them suitable for withstanding higher switching frequencies. Thus, reducing the power losses in the devices compared to silicon solutions.

Today, transistors are an elementary unit in the field of microelectronics which is basically a switch controlled by voltage. Meeting the requirement for more power affects the size of transistors which is now being fixed by the use of WBG materials. Silicon carbide and gallium nitride are in great demand for their contribution to power systems and are achieved by the implementation of these materials in transistors and the development of newer substrates.

Figure 1: GaN Market Evolution [Source: Yolè Developpment]

GaN on Si power transistors is contributing to many space and radar-related applications. Earlier, power supplies were not using topologies, but now it is possible with the use of GaN which has zero reverse recovery charge. Silicon power transistors have a repetitive reverse recovery charge that leads to a large peak current value. This does not allow it to be used in conversion topologies and half-bridge topologies. Hence, Gallium on silicon transistors with more efficiency, more suitability for large diameter wafer CMOS boundaries, and high-frequency functionality is being used. Integrating substrates with power amplifiers, low-noise amplifiers, and switch reduces the overall cost of manufacturing. GaN on Si is useful in integrating these components on the substrate as it is effective for high power, high terminal connectivity implementation. Silicon will continue to be used for many applications but WBG semiconductors allow customers to get devices with improved traits like high frequency, and high voltage lowering the energy loss in the form of heat. Thus, improving the life of devices.

An Analysis of Market Opportunities for WBG Semiconductors

New market opportunities are emerging for wide-bandgap semiconductors as they offer relevant features and applications when compared to silicon-based semiconductor power devices. These WBG semiconductor power devices can operate at higher temperatures and frequencies, making them more convenient for market expansion. Furthermore, GaN provides obvious advantages over Si which is limited only to lower-power applications. Gallium nitride makes the devices more efficient by offering compact higher power designs (tens of watts or kilowatts) that can operate at higher switching frequencies thus, providing benefits to the customers.

Mobile phones with enhanced functionality and efficient charging systems are in high demand, and wireless charging system is now emerging as a new topic of research. Large and efficient batteries are essential for cell phone services including data transfer at high speeds, screens with improved quality, face sensors, and so on. The chargers which are now available in the market require a minimum of two hours to charge the device fully. Si is a low-power operating material while GaN can reach higher power hence it takes lesser time for charging the device.

Figure 2: GaN Fast Charging Trends [Source: Yolè Developpment]

Silicon is still in use for devices that operate between 30 and 100 Watts but GaN proves to be more dominant. It offers higher efficiency, fast charging times, thermal management properties, and a compact design and is leading in the semiconductor market.

Advancement in the Automotive industry

Wide bandgap power devices are widely used in automobiles because of their high performance. It is commonly used in Electric vehicle systems (EV) and hybrid electric vehicles (HEV) applications like offboarding charging that requires fast chargers and charging systems. While both SiC and GaN are effectively implemented in EV systems, SiC is considered to be more advanced in the automotive sector, and choosing the best material largely depends on the strategy and schemes adopted by OEMs keeping cost and performance in mind. Tesla and other companies, such as BYD, have already considered SiC in main inverters and onboard charger applications.

Figure 3: Power GaN Market [Source: Yolè Developpment]

Gallium nitride is now also taking its place in low and high-voltage EV and HEV applications. Companies like EPC and transform are implementing gallium nitride devices for the automotive sector while Nexperia is investing in the market with new approaches and technical strategies. Mass production led to challenges that necessitate well-planned manufacturing processes like wafer testing of smaller devices operating at high currents and voltage. Because of increased manufacturing process costs and a lack of volume production, the most difficult challenge is the wide acceptance of SiC/GaN devices.

Conclusion

Customers are now getting benefit from WBG semiconductor devices that offers properties like higher current density, faster-switching conditions, and lower drain-source on-resistance (R_DS). These devices are bringing a revolution in various markets like Automotive, industrial, and consumer. Gallium nitride and silicon nitride are well-suited materials for devices operating at high power and temperature. Because silicon carbide is inexpensive to produce, it is used for high-efficiency electric vehicle charging, long-lasting solar and wind energy power converters, and eliminating bulky grid substation transformers.