Electrical properties of ohmic contacts for Al0.3Ga0.7N/GaN semiconductor devices

Electrical properties of the ohmic contacts for Al_0.3Ga_0.7N/GaN semiconductor devices were investigated. Two different preparation techniques were used, electron beam evaporation (EBE) and pulsed laser deposition (PLD). The EBE contacts show more than 10-times lower specific contact resistance than those prepared by PLD. Characterization of the HFETs prepared yielded higher saturation drain current and peak transconductance if EBE ohmic contacts were used comparing to PLD ohmic contacts. An optimisation of the PLD procedure to be used at the Al_0.3Ga_0.7N/GaN device preparation is in progress.