【International Papers】Effect of dislocations and impurities on carrier transport in α-Ga₂O₃ on m-plane sapphire substrate

      Researchers from the Kyoto University and Hyogo Prefectural Institute of Technology have published a dissertation titled "Effect of dislocations and impurities on carrier transport in α-Ga₂O₃ on m-plane sapphire substrate" in the scientific journal SpringerLink.

Abstract

      Carrier transport mechanism in Si-doped n-type α-Ga₂O₃ thin film on m-plane sapphire substrate was investigated by temperature-dependent Hall effect measurements (30–300 K). All films show dislocation density of about ~ 10¹⁰–10¹¹ cm⁻². In non-degenerate α-Ga₂O₃, an impurity-band effect is obvious in the low temperature region, and dislocation scattering is the dominant scattering mechanism. In contrast, in degenerate α-Ga₂O₃, although the dislocation density is comparable to the non-degenerate one, the mobility is dominated by ionized impurity scattering, due to the heavy screening of charged dislocations. The analysis indicates that the carrier transport mechanism in α-Ga₂O₃ with high dislocation density is different from each other depending on whether α-Ga₂O₃ is degenerate or non-degenerate. Finally, we estimate critical dislocation density for dislocation-insensitive mobility in α-Ga₂O₃ on sapphire substrate, and indicate that dislocation densities below ~ 1 × 10⁷–1 × 10⁸ cm⁻² will be required for lightly doped drift layers in devices.

Paper Link：https://link.springer.com/article/10.1557/s43578-023-01015-8