Si doping of beta-Ga2O3 by disilane via hybrid plasma-assisted molecular beam epitaxy

Obtaining uniform silicon concentration, especially with low concentrations (ranging from 1 x 10(16) to 1 x 10(18) cm(-3)) by molecular beam epitaxy, has been challenging due to oxidation of a silicon solid source in the oxide environment. In this work, Si doping of beta-Ga2O3 (010) films by diluted disilane as the Si source is investigated using hybrid plasma-assisted molecular beam epitaxy. The impact of growth temperature, disilane source concentration, and disilane flow rate on Si incorporation was studied by secondary ion mass spectrometry. Uniform Si concentrations ranging from 3 x 10(16) to 2 x 10(19) cm(-3) are demonstrated. Si-doped beta-Ga2O3 films with different silicon concentrations were grown on Fe-doped beta-Ga2O3 (010) substrates. The electron concentration and mobility were determined using van de Pauw Hall measurements. A high mobility of 135 cm(2)/V s was measured for an electron concentration of 3.4 x 10(17) cm(-3) at room temperature.