A semiconductor device is disclosed. The semiconductor device includes a substrate, an epitaxial layer on the substrate, a semiconductor interlayer on top of the epitaxial layer, a gate conductor above the semiconductor interlayer, a gate insulator on the bottom and sides of the gate conductor and contacting the top surface of the semiconductor interlayer, a source region extending into the epitaxial layer, and a drain region extending into the epitaxial layer. The semiconductor device also includes a first polarization layer on the semiconductor interlayer between the source region and the gate conductor and a second polarization layer on the semiconductor interlayer between the drain region and the gate conductor.