III-Nitride Vertical Hot Electron Transistor with Polarization Doping and Collimated Injection

III-nitride-based hot electron transistors (HETs) offer significant promise as high-speed, high-power devices, but their performance has been limited to below that of competing technologies. A HET with collector current density >440 kA/cm^2 and common-emitter current gain >75 is disclosed. Polarization engineering of the emitter stack was used to allow for high-current collimated electron injection from the emitter with relatively low turn-on voltage. The use of only polarization charge in the undoped 10 nm-thick base allowed for high gain, through minimization of scattering, with atomic layer etching contact fabrication used to lower base access resistance.