Importance

Loading Importance Indicators...

Abstract

A semiconductor wafer includes first and second superlattice layers. The first superlattice layer includes first unit layers each of which includes first and second layers, the second superlattice layer includes second unit layers each of which includes third and fourth layers, the first layer is made of Al_x1Ga_1-x1N (0y1Ga_1-y1N (0≦y1<1, x1>y1), the third layer is made of Al_x2Ga_1-x2N (0y2Ga_1-y2N (0≦y2<1, x2>y2), an average lattice constant of the first superlattice layer is different from that of the second superlattice layer, and one or more layers selected from the first and second superlattice layers contain impurity atoms that improve a breakdown voltage and that have a concentration higher than 7×10¹⁸ [atoms/cm³].

Loading the Abstract Image...

First Claim