PROJECT TITLE :

Common Emitter Current Gain >1 in III-N Hot Electron Transistors With 7-nm GaN/InGaN Base

ABSTRACT:

Current gain is demonstrated in III-N hot electron transistors (HETs) for the first time using base current controlled common emitter characteristics. The emitter and collector barriers (ØBE and ØBC) are implemented using AlN and In0.1Ga0.9N layers as polarization-dipoles, respectively. The whole structure is grown by plasma-assisted molecular beam epitaxy. Current gain is observed when the bottom thickness is reduced from 13 to 7 nm. Ohmic contacts to the base two-D electron gas (2DEG) are achieved employing a BCl3/SF6 etch to remove the emitter and selectively stop on the AlN. Subsequent metallization leads to a tunnel contact from the metal to the bottom 2DEG across the skinny AlN layer. This twin purpose served by the AlN layer is shown to be crucial for achieving scaled base and current gain in III-N HETs.