Texas Instruments Incorporated
NORMALLY-ON GALLIUM NITRIDE BASED TRANSISTOR WITH P-TYPE GATE

Abstract:

A semiconductor device includes a gallium nitride based low threshold depletion mode transistor (GaN FET) with a threshold potential between -10 volts and -0.5 volts. The GaN FET has a channel layer of III-N semiconductor material including gallium and nitrogen that supports a two-dimensional electron gas (2 DEG). The GaN FET has a barrier layer of III-N semiconductor material including aluminum and nitrogen over the channel layer. The GaN FET further has a p-type gate of III-N semiconductor material including gallium and nitrogen. A bottom surface of the gate, adjacent to the barrier layer, does not extend past a top surface of the barrier layer, located opposite from the channel layer. The GaN FET is free of a dielectric layer between the gate and the barrier layer.