GaAs MOSFETs fabrication with a selective liquid phase oxidized gate

The N-channel depletion-mode GaAs MOSFETs with a liquid phase chemical enhanced selective gate oxide grown at low temperature are demonstrated. The proposed selective oxidation method makes the fabrication process of GaAs MOSFETs more reliable and self side-wall passivation possible. The fabricated GaAs MOSFETs exhibit current-voltage characteristics with complete pinch-off and saturation characteristics. The 2 μm gate-length MOSFETs with a gate oxide thickness of 35 nm show transconductance larger than 80 mS/mm and maximum drain current density of 380 mA/mm. In addition, microwave characteristics with f_T of 1.8 GHz and f_max of 5.2 GHz have been achieved from the 3 μm×60 μm GaAs MOSFETs