Dielectric properties of low-temperature-grown homoepitaxial (−201) β-Ga2O3 thin film by atmospheric pressure plasma-assisted CVD

Abstract

The atmospheric pressure plasma-assisted chemical vapor deposition technique has successfully demonstrated unintentionally doped (UID) Ga2O3 growth at 350 °C. This technique allows independent and homogeneous multiple nuclei growth of Ga2O3, leading to three-dimensional grain growth at a rate of ⁓0.17 μm/h. In the study of Schottky barrier diodes, the Schottky-like current (I)–voltage (V) response shows typical behavior on Ga2O3. This is a good sign at an early stage of device development on the grown sample. The extracted barrier height of ⁓2.20 eV was higher, which may be due to unintentional PtOx formation on the Ga2O3 surface. Furthermore, the extracted capacitance (C)–voltage (V) depth profiling of the effective impurity concentration was nearly flat, ⁓1.5 × 1017 cm−3, in the unintentionally doped grown film. The effective impurity concentration is comparable to the UID carrier concentration of epitaxial films fabricated using the high temperature growth technique. Therefore, low-temperature-grown homoepitaxial Ga2O3 thin films grown by atmospheric pressure-plasma-assisted chemical vapor deposition can be used in future Ga2O3-based power device applications.