Further Characterization of the Polycrystalline p-Type β-Ga2O3 Films Grown through the Thermal Oxidation of GaN at 1000 to 1100 °C in a N2O Atmosphere

The development of good-conductivity p-type beta-Ga2O3 is crucial for the realization of its devices and applications. In this study, nitrogen-doped p-type beta-Ga2O3 films with the characteristics of enhanced conductivity were fabricated through the thermal oxidation of GaN in a N2O atmosphere. To obtain insights into the underlying mechanism of the thermally activated transformation process, additional measurements of the oxidized films were performed at temperatures of 1000, 1050, and 1100 C-degrees. Room-temperature photoluminescence (PL) spectra showed a moderate ultraviolet emission peak at 246 nm, confirming the generation of gallium oxide with a band gap of approximately 5.0 eV. The characteristics of polycrystalline and anisotropic growth were confirmed via normalized X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and selected-area electron diffraction (SAED) patterns. The amount of incorporated nitrogen was analyzed via secondary ion mass spectrometry (SIMS) to examine the effects of oxidation temperature. Furthermore, the ionization energy of the acceptor in the films oxidized at 1000, 1050, and 1100 C-degrees was calculated and analyzed using temperature-dependent Hall test results. The results indicated that nitrogen doping played a significant role in determining p-type electrical properties. The activation energy of polycrystalline beta-Ga2O3, prepared via the thermal oxidation of GaN in the N2O atmosphere, was estimated to be 147.175 kJ center dot mol(-1) using an Arrhenius plot. This value was significantly lower than that obtained via both the dry and wet oxidation of GaN under O-2 ambient conditions, thus confirming the higher efficiency of the thermal oxidation of GaN in a N2O atmosphere.

Automated summary

Nitrogen-doped p-type β-Ga2O3 films with enhanced conductivity were fabricated through the thermal oxidation of GaN in a N2O atmosphere. The results showed that nitrogen doping played a significant role in determining p-type electrical properties and the thermal oxidation of GaN in a N2O atmosphere was more efficient.