Research on DC Characteristics of β-(Al_0.22Ga_0.78)₂O₃/β-Ga₂O₃ Modfet

This research paper elucidates the significant impact of four key parameters—barrier layer thickness (H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Barrier</inf>), gate length (L<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</inf>), δ-doping layer thickness, and δ-doping layer concentration—on the transport and output characteristics of β-(Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.22</inf>Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.78</inf>)<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>/β-Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> HEMTs. Increasing the barrier layer thickness (H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Barrier</inf>) gradually decreases the device’s threshold voltage, enhances the two-dimensional electron gas (2DEG) concentration in the channel, and improves the output characteristics. Decreasing the gate length (L<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</inf>) leads to a gradual decrease in the threshold voltage, an increase in the 2DEG concentration, and an enhancement of the device’s output characteristics. The role of the δ-doping layer is to pull the conduction band closer to the Fermi level, thereby deepening the potential well. Increasing the thickness or concentration of the δ-doping layer further increases the 2DEG concentration, while simultaneously lowering the threshold voltage and enhancing the device’s output characteristics. Notably, the barrier layer thickness has the most significant impact on the threshold voltage; when the thickness is reduced to 10 nm, the device transitions from depletion mode to enhancement mode. Gate length and δ-doping thickness have a significant impact on transconductance, on-resistance, as well as the maximum current density and carrier concentration. Furthermore, the δ-doping concentration has an important influence on all performance parameters of the device. By rationally adjusting these parameters, precise tuning and optimization of device performance can be achieved. However, due to the coupling between these parameters, caution must be exercised in their selection and adjustment in practical applications to ensure that the device operates at its optimal performance level.