Hemt device having an improved conductivity and manufacturing process thereof

A process for manufacturing a HEMT device, comprising:

• forming a gate region on a semiconductor body, the gate region being elongated along a first axis;
• forming a gate metal region including a respective lower portion, which is on the gate region and is laterally recessed with respect to the gate region, and a respective upper portion, which is on the lower portion and has a width greater that the lower portion along a second axis;
• forming a source metal region extending on the semiconductor body and including aluminum;
• forming a drain metal region of conductive material, which extends on the semiconductor body, the source metal region and the drain metal region extending on opposite sides of the gate region;
• and
• forming a first conductivity enhancement region of aluminum nitride, which extends on the semiconductor body and is laterally interposed between the source metal region and the gate region, the first conductivity enhancement region being in direct contact with the source metal region and being separated from the gate region.

A HEMT device, comprising:

• a heterostructure having a first surface;
• a gate region on the first surface, the gate region having a second surface opposing the first surface;
• a gate conductive region on the second surface;
• an insulating layer on the first surface and the second surface;
• a conductivity enhancement region on the first surface and the insulating layer, and spaced from the gate region;
• and
• a source conductive region on the first surface and in contact with the conductivity enhancement region.