Semiconductor device

摘要

A semiconductor device includes a superlattice buffer layer formed on a substrate. A first semiconductor layer is formed by a nitride semiconductor on the superlattice buffer layer. A second semiconductor layer is formed by a nitride semiconductor on the first semiconductor layer. A gate electrode, a source electrode and a drain electrode are formed on the second semiconductor layer. The superlattice buffer layer is formed by alternately and periodically laminating a first superlattice formation layer and a second superlattice formation layer. The first superlattice formation layer is formed by AlxGa1-xN and the second superlattice formation layer is formed by AlyGa1-yN, where a relationship x>y is satisfied. A concentration of an impurity element serving as an acceptor doped into a portion or a whole of the second superlattice formation layer is higher than a concentration of the impurity element serving as an acceptor doped into the first superlattice formation layer.

主权项

1. A semiconductor device comprising:
a superlattice buffer layer formed on a substrate; a first semiconductor layer formed by a nitride semiconductor on said superlattice buffer layer; a second semiconductor layer formed by a nitride semiconductor on said first semiconductor layer; and a gate electrode, a source electrode and a drain electrode formed on said second semiconductor layer, wherein said superlattice buffer layer is formed by alternately and periodically laminating a first superlattice formation layer and a second superlattice formation layer, said first superlattice formation layer is formed by AlxGa1-xN and said second superlattice formation layer is formed by AlyGa1-yN, where a relationship x>y is satisfied, and a concentration of an impurity element serving as an acceptor doped into a portion or a whole of said second superlattice formation layer is higher than a concentration of the impurity element serving as an acceptor doped into said first superlattice formation layer.