LAUSR

Abstract The nonpolar a-plane p-AlxGa1-xN/GaN superlattices (SLs) were successfully grown with metal organic chemical vapor deposition technology. The surface morphology, carrier concentration, layer thickness, and Al composition for the nonpolar a-plane p-AlxGa1-xN/GaN SLs were characterized by various kinds of technical tools. It was demonstrated that the thickness of the AlxGa1-xN and GaN layers in SLs was calculated to be 12 and 14.5 nm, respectively and the Al composition of the AlxGa1-xN layers in SLs was around 30%. Meanwhile, the results reveal that the surface morphology and carrier concentration of the nonpolar p-SLs could be improved remarkably with the Al composition-graded AlGaN buffer layer and the Mg-δ-doping process. Consequently, a root mean square value of 0.6 nm and a hole concentration of 4.2 × 1017 cm−3 were achieved.