Abstract
A semiconductor device includes first to third nitrogen-based semiconductor layers, a source electrode, a drain electrode, and a gate electrode. The second nitrogen-based semiconductor layer is disposed on the first nitrogen-based semiconductor layer and has a band gap smaller than that of the first nitrogen-based semiconductor layer so that a heterojunction having a two-dimensional hole gas (2DHG) region is formed therebetween. The third nitrogen-based semiconductor layer is embedded in the second nitrogen-based semiconductor layer and is spaced apart from the first nitrogen-based semiconductor layer. The third nitrogen-based semiconductor layer is doped so as to have a first conductivity type different from a conductivity type of the second nitrogen-based semiconductor layer.