Intentional Control of n-type Conduction for Si-doped AlN and AlxGa1?xN with High Al Content

N-type conductive Si-doped AlN and AlxGa1—xN with high Al content have been obtained by intentionally controlling the Si dopant density [Si]. Self-compensation plays an important role at higher [Si] and determines the upper doping limit of Si. The Si-doped AlN showed n-type conduction when [Si] was less than 3 × 1019 cm—3. When [Si] was more than 3 × 1019 cm—3, it became highly resistive due to the self-compensation of Si donors. For x > 0.49, the ionization energy of Si donors increased sharply with increasing Al content. This resulted in a sharp decrease in the highest obtainable electron concentration with increasing Al content for the Si-doped AlxGa1—xN.