Abstract
This invention provides an enhancement mode GaN-based MOSFET, which comprises a substrate of a hexagonal system crystal structure, a first GaN layer disposed on the substrate and containing first conductive dopants therein, a pair of source and drain extending apart from the inner first GaN layer toward the surface thereof, a gate dielectric layered structure covering the first GaN layer in which the pair of the source and the drain are not formed and having a MgO layer and an oxide layer, that contains Ti and Mg therein and is formed on the MgO layer, and a gate formed on the gate dielectric layered structure.