GaN HEMTs
Gallium nitride (GaN) is an established wide band gap semiconductor material, which is used in particular for LEDs or in power electronics. GaN HEMTs (High-Electron-Mobility Transistors) are transistors that are predestined for use in radio frequency (RF) technology due to their high charge carrier mobility and are used, for example, for RF circuits of smartphones.
The 5G mobile communications standard is expected not only to revolutionize our communications and networking, but also to make the triumphant advance of GaN RF transistors unstoppable. 5G uses frequency ranges up to 100 GHz and offers high data rates up to 10 gigabits per second, as well as higher network density and more efficient power consumption. RF power transistors with GaN technology outshine currently used RF power transistors in terms of efficiency, bandwidth and power density and are ideally suited for 5G applications.
What makes a GaN HEMT?
Gallium nitride has about ten times the breakdown field strength of silicon, which is why GaN HEMTs enable significantly higher power densities and switching frequencies than silicon-based transistors such as SJ MOSFETs or IGBTs. Due to their high saturation speed and charge carrier mobility, they are ideally suited for high frequencies and fast switching.
Sandwich-like structure
In conventional transistors, the semiconductor material is doped with foreign atoms to create electrical conductivity. However, this "impurity" has a negative effect on the electron velocity. The structure of HEMTs, on the other hand, is characterized by a sandwich-like structure of pure semiconductor materials with band gaps of different sizes, thus avoiding this effect.
Wide band gap
The wide band gap of the AlGaN-GaN heterojunction allows very high operating voltages. A very conductive electron layer emerges at the interface, forming the channel in the transistor, the so-called two-dimensional electron gas (2DEG). This makes it possible to realize unipolar devices with a particularly large ratio of dielectric strength to area-related on-resistance that exhibit only low switching losses.
How does centrotherm process technology contribute?
For the production of components based on compound semiconductors such as gallium nitride, we develop process equipment for high-temperature annealing and thermal deposition of oxides.
