Low temperature homoepitaxy of (010) β-Ga2O3 by metalorganic vapor phase epitaxy: Expanding the growth window

In this work, we report on the growth of high-mobility beta-Ga2O3 homoepitaxial thin films grown at a temperature much lower than the conventional growth temperature window for metalorganic vapor phase epitaxy. Low-temperature beta-Ga2O3 thin films grown at 600 degrees C on Fe-doped (010) bulk substrates exhibit remarkable crystalline quality, which is evident from the measured room temperature Hall mobility of 186cm(2)/Vs for the unintentionally doped films. N-type doping is achieved by using Si as a dopant, and a controllable doping in the range of 2x10(16)-2x10(19)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 (2x10(15)cm(-3)) even at this growth temperature. Additionally, an abrupt doping profile with a forward decay of similar to 5nm/dec (10 times improvement compared to what is observed for thin films grown at 810 degrees C) is demonstrated by growing at a lower temperature.