PGaN enhancement mode HEMTs with dopant diffusion spacer

A system comprising:

• a power supply;
• and
• a radio transceiver electrically coupled to the power supply, wherein at least one of the power supply and the radio transceiver comprise a Group III-nitride (III-N) transistor, and
• wherein the III-N transistor comprises:
• a channel layer comprising a first Group III-nitride (III-N) material;
• a polarization layer over the channel layer, wherein the polarization layer comprises a second III-N material with more Al than the first III-N material;
• a p-type layer over the polarization layer, wherein the p-type layer is a binary alloy of Ga and N comprising Mg;
• a spacer layer between the polarization layer and the p-type layer, wherein the spacer layer is in contact with the p-type layer and is a binary alloy of Ga and N that has a lower concentration of Mg than the p-type layer;
• a gate terminal over the spacer layer;
• and
• source and drain terminals coupled to the channel layer.

An apparatus, comprising:

• a transistor channel layer comprising a first III-N material;
• a polarization layer over the channel layer, wherein the polarization layer comprises a second III-N material with more Al than the first III-N material;
• a p-type layer over the polarization layer, wherein the p-type layer has a thickness of at least 5 nm and comprises a III-N material comprising a P-type impurity at a concentration of at least 1e19 atoms/cm3;
• a spacer layer between the polarization layer and the p-type layer, wherein the spacer layer has a thickness of 2-10 nm and comprises a III-N material with a lower concentration of the P-type impurity than the p-type layer;
• a transistor gate terminal over the spacer layer;
• and
• transistor source and drain terminals coupled to the transistor channel layer.