Abstract
Some embodiments of the invention provides a semiconductor device. The semiconductor device comprises the components of a substrate; a first nitrode semiconductor layer which is on the substrate; a second nitride semiconductor layer which is on the first nitride semiconductor layer and has a bandgap that is larger than that of the first nitride semiconductor layer; an III-V-group dielectric layerwhich is placed on the second nitride semiconductor layer; a gate electrode which is placed on the second nitride semiconductor layer; and a first passivation layer which is placed on the III-V-groupdielectric layer, wherein the III-V-group dielectric layer is separated from the gate electrode through the first passivation layer.