AN ENHANCEMENT MODE METAL INSULATOR SEMICONDUCTOR HIGH ELECTRON MOBILITY TRANSISTOR

An enhancement mode metal insulator semiconductor high electron mobility transistor (HEMT) is presented herein. By using a polarization stack to replace the traditional barrier layer, a thinner barrier layer (e.g., a thinner layer of AlGaN) may be formed during fabrication to effectuate a low-sheet-resistance two-dimensional electron gas. Advantageously, the thinner (.i.e., less-than-ten nanometers) barrier layer mitigates reactive ion etching (RIE) induced surface damage. This in turn allows the formation of a recessed gate. Additionally, a dual dielectric gate stack may be deposited to further reduce leakage currents and to improve subthreshold slope.