Low resistivity of highly Si-doped n-type Al 0.62 Ga 0.38 N layer by suppressing self-compensation

The lowest resistivity of highly Si-doped Al0.62Ga0.38N was achieved using metalorganic vapor epitaxy. The resistivity strongly depended on the Si concentrations and reached a minimum value of 6.6 x 10(-3) Omega cm at a Si concentration of 3.2 x 10(19) cm(-3), where the carrier concentration was close to the Si one. Above this concentration, luminescence bands around 2.4 eV originating from group-III-vacancy-Si complexes (V-III-nSi) were observed, whereas carrier concentrations and mobilities decreased. Growth conditions that avoid high temperatures and V/III ratios result in suppressed formation of V-III-nSi, playing a key role in achieving low resistivity. (C) 2020 The Japan Society of Applied Physics