Patent ID: 9196685
Filing Date: 2015-11-24
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first superlattice buffer layer formed on a substrate; a second superlattice buffer layer formed on said first superlattice buffer layer; a first semiconductor layer formed by a nitride semiconductor on said second 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 first superlattice buffer layer is formed by alternately and cyclically laminating a first superlattice formation layer and a second superlattice formation layer, and said second superlattice buffer layer is formed by alternately and cyclically laminating the first superlattice formation layer and the second superlattice formation layer, and the first superlattice formation layer is formed by Al a concentration of an impurity element serving as an acceptor doped into said second superlattice buffer layer is higher than a concentration of an impurity element serving as an acceptor doped into said first superlattice buffer layer.