LAUSR

The semi-polar $$\left(11\overline{2}2\right)$$112¯2 plane Al0.42Ga0.58N films were successfully grown on $$\left(10\overline{1}0\right)$$101¯0-oriented m-plane sapphire substrates for the first time with an indium (In)-surfactant-assisted metal–organic chemical vapor deposition (MOCVD) technology. The crystal orientation, surface morphology, and electrical properties of the grown semi-polar $$\left(11\overline{2}2\right)$$112¯2 plane AlGaN epi-layers were characterized with high-resolution X-ray diffraction (HR-XRD), atomic force microscopy (AFM), and Hall effect measurements, respectively. The XRD scanning results showed that crystalline quality for the semi-polar $$\left(11\overline{2}2\right)$$112¯2 plane AlGaN epi-layer was improved with In-surfactant. The AFM results demonstrated that the root mean square value of the semi-polar AlGaN epi-layer samples decreased with increasing the TMIn mole flow rate. Furthermore, the native electron concentration of the unintentionally doped semi-polar $$\left(11\overline{2}2\right)$$112¯2 plane AlGaN epi-layers was decreased from 2.66 × 1017 to 2.97 × 1016 cm−3 due to the significant decrease in nitrogen vacancies (VN) with indium-surfactant-assisted growth process.