The Unknown SiC and GaN in 2020
The evolution of wide band gap materials has been keeping pace as new technology demands looks for advance performance and reliability. Their ability to operate at higher temperatures, higher power densities, higher voltages and higher frequencies make them highly interesting for use in future electronic systems. Two very important wide bandgap materials showing great promise for the future for both switching and RF power applications are Gallium Nitride (GaN) and Silicon Carbide (SiC). As innovation becomes more competitive and rigorous the debate between Gallium Nitride (GaN) versus Silicon Carbide (SiC) material has taken pace. The semiconductor devices which are possible and which device / material is best suited for various switching and RF power applications.
Critical Field of GaN and SiC
The high critical field of both GaN and SiC compared to Si is a property which allows these devices to operate at higher voltages and lower leakage currents. Higher electron mobility and electron saturation velocity allow for higher frequency of operation. While SiC has higher electron mobility than Si, GaN’s electron mobility is higher than SiC meaning that GaN should ultimately be the best device for very high frequencies. Higher thermal conductivity means that the material is superior in conducting heat more efficiently.
Characteristics of SiC and GaN
This wider bandgap makes GaN highly suitable for optoelectronics and is key to producing devices such as UV LEDs where frequency doubling is impractical. Not only do GaN semiconductors have 1000 times the electron mobility than silicon they are also able to operate at higher temperatures while still maintaining their characteristics (up to 400 degrees Celsius). These combined characteristics would make GaN highly desirable in high frequency (THz), high temperature, and high power environments.