Si-doped (AlGa)₂O₃ growth on a-, m- and r-plane α-Al₂O₃ substrates by molecular beam epitaxy

We reported the growth of (AlGa) 2 O 3 layers on (11 2 ¯ 0), (10 1 ¯ 0), and (10 1 ¯ 2) α -Al 2 O 3 substrates using MBE, and the electrical characterization of Si-doped (AlGa) 2 O 3 layers. The Ga 2 O 3 layers grown on (10 1 ¯ 0) and (10 1 ¯ 2) α -Al 2 O 3 were α -phase single crystals, while the Ga 2 O 3 layer grown on (11 2 ¯ 0) α -Al 2 O 3 consisted of (11 2 ¯ 0) α -Ga 2 O 3 and ( 2 ¯ 01) β -Ga 2 O 3 . The Al composition of the (11 2 ¯ 0) and (10 1 ¯ 0) (AlGa) 2 O 3 layers was controlled by varying the Al flux. The Si-doped (10 1 ¯ 0) α -(Al x Ga 1- x ) 2 O 3 layers with x = 0–0.41 were electrically conducting.