a III-N material structure comprising a III-N channel layer over a III-N barrier layer, a p-type III-N layer over and directly contacting the III-N channel layer, and a 2DEG channel formed adjacent an interface between the III-N channel layer and the III-N barrier layer;

an n-type III-N layer over and directly contacting the p-type III-N layer,

a source electrode, a gate electrode, and a drain electrode each on a same side of the III-N material structure;

a gate insulator layer separating the gate electrode from the p-type III-N layer and the III-N channel layer; wherein

the source electrode directly contacts the n-type III-N layer and is electrically connected to the p-type III-N layer;

the drain electrode is electrically connected to the 2DEG channel;

a portion of the III-N channel layer separates the gate insulator layer from the III-N barrier layer;

the p-type III-N layer is over the III-N channel layer in a source side access region of the device and does not extend past the gate electrode; and

the 2DEG channel extends continuously through the III-N channel layer from below the source electrode to the drain electrode and the source electrode is electrically isolated from a portion of the 2DEG channel below the source electrode when the gate electrode is biased relative to the source electrode at a voltage that is below a threshold voltage of the device.