High electron density β-(Al0.17Ga0.83)2O3/Ga2O3 modulation doping using an ultra-thin (1 nm) spacer layer.

This report discusses the design and demonstration of β -(Al_0.17Ga_0.83)₂O₃/Ga₂O₃ modulation doped heterostructures to achieve high sheet charge density. The use of a thin spacer layer between the Si delta-doping and the heterojunction interface was investigated in a β -(AlGa)₂O₃/Ga₂O₃ modulation doped structure. It is shown that this strategy enables a higher two-dimensional electron gas (2DEG) sheet charge density up to 4.7 × 10¹² cm⁻² with an effective mobility of 150 cm²/V s. The presence of a degenerate 2DEG channel was confirmed by the measurement of a low temperature effective mobility of 375 cm²/V s and the lack of carrier freeze out from low temperature capacitance voltage measurements. The electron density of 4.7 × 10¹² cm⁻² is the highest reported 2DEG density obtained without parallel conducting channels in a β -(Al_xGa_(1−x))₂O₃/Ga₂O₃ heterostructure system. [ABSTRACT FROM AUTHOR]