SEMICONDUCTOR DEVICE, COMMUNICATION MODULE, AND SEMICONDUCTOR DEVICE MANUFACTURING METHOD

A semiconductor device includes: a semiconductor substrate; a channel layer on the semiconductor substrate; a barrier layer on the channel layer; a gate electrode on the barrier layer via a gate insulating film; a source electrode and a drain electrode on the channel layer with the gate electrode interposed therebetween; a substrate opening that penetrates the channel layer and exposes the semiconductor substrate; an insulating film provided from upper parts of the gate electrode, the source electrode, and the drain electrode to an inner side of the substrate opening; and a wiring line layer on the insulating film, and electrically coupled to one of the gate electrode, the source electrode, and the drain electrode via an opening on the insulating film, in which at least a portion of the substrate opening is in an activation region in which the gate electrode, the source electrode, and the drain electrode are provided.