Low temperature homoepitaxy of (010) -Ga2O3by metalorganic vapor phase epitaxy: Expanding the growth window

Abstract

In this work, we report on the growth of high-mobility -Ga2O3 homoepitaxial thin films grown at a temperature much lower than the conventional growth temperature window for metalorganic vapor phase epitaxy. Low-temperature -Ga2O3 thin films grown at 600 °C on Fe-doped (010) bulk substrates exhibit remarkable crystalline quality, which is evident from the measured room temperature Hall mobility of 186 cm2/V s for the unintentionally doped films. N-type doping is achieved by using Si as a dopant, and a controllable doping in the range of 2 × 1016-2 × 1019 cm-3 is studied. Si incorporation and activation is studied by comparing the silicon concentration from secondary ion mass spectroscopy and the electron concentration from temperature-dependent Hall measurements. The films exhibit high purity (low C and H concentrations) with a very low concentration of compensating acceptors (2 × 1015 cm-3) even at this growth temperature. Additionally, an abrupt doping profile with a forward decay of ∼5 nm/dec (10 times improvement compared to what is observed for thin films grown at 810 °C) is demonstrated by growing at a lower temperature.