US Patent 10229977 Nitrogen-containing semiconductor device

A nitrogen-containing semiconductor device including a substrate, a first AlGaN buffer layer, a second AlGaN buffer layer and a semiconductor stacking layer is provided. The first AlGaN buffer layer is disposed on the substrate, and the second AlGaN buffer layer is disposed on the first AlGaN buffer layer. A chemical formula of the first AlGaN buffer layer is AlxGa1-xN, wherein 0≤x≤1. The first AlGaN buffer layer is doped with at least one of oxygen having a concentration greater than 5×1017 cm−3 and carbon having a concentration greater than 5×1017 cm−3. A chemical formula of the second AlGaN buffer layer is AlyGa1-yN, wherein 0≤y≤1. The semiconductor stacking layer is disposed on the second AlGaN buffer layer.