Turbocharging AlN/GaN HEMTs

Engineers from Ohio State University are claiming to have opened the door to the fabrication of far smaller AlN/GaN HEMTs operating at much higher frequencies.

The team’s breakthrough involves the combination of in-situ passivation and the addition of re-grown heavily doped n-type contacts using a selective etching process.

AlN/GaN HEMTs are a very promising class of transistor for RF and power devices. Compared with the more conventional AlGaN/GaN form of the III-N HEMT, they are free from alloy scattering and have far higher values for electron mobility and the density of the two-dimensional electron gas – up to 4 x 1013 cm-2, and between 1000 cm2 V-1 s-1 and 1800 cm2 V-1 s-1, respectively.