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

Carrier transport mechanism in Si-doped n-type alpha-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 similar to 10(10)-10(11) cm(-2). In non-degenerate alpha-Ga2O3, an impurity-band effect is obvious in the low temperature region, and dislocation scattering is the dominant scattering mechanism. In contrast, in degenerate alpha-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 alpha-Ga2O3 with high dislocation density is different from each other depending on whether alpha-Ga2O3 is degenerate or non-degenerate. Finally, we estimate critical dislocation density for dislocation-insensitive mobility in alpha-Ga2O3 on sapphire substrate, and indicate that dislocation densities below similar to 1 x 10(7)-1 x 10(8) cm(-2) will be required for lightly doped drift layers in devices.

Automated summary

The carrier transport mechanism in Si-doped n-type alpha-Ga2O3 thin film on m-plane sapphire substrate was investigated. The study found that the carrier transport mechanism in alpha-Ga2O3 with high dislocation density differs depending on whether alpha-Ga2O3 is degenerate or non-degenerate. It was also estimated that dislocation densities below approximately 1 x 10^7-1 x 10^8 cm^-2 will be required for lightly doped drift layers in devices.