Physics-Based Compact I–V Model for δ-Doped β-(AlxGa1−x)₂O₃/Ga₂O₃ HFET Involving Parallel Conduction

In this article, we present a physics-based model for drain current calculation in delta (
$\delta $
)-doped
$\beta $
-(AlxGa1−x)2O3/Ga2O3 heterostructure field-effect transistor (HFET). The presented model also takes into account the effect of parallel conduction in the
$\beta $
-(AlxGa1−x)2O3 layer at higher gate voltages (
${V}_{\text {g}}$
). At gate voltage below parallel pinch-off voltage (
${V}_{\text {gop}}$
), drain current (
${I}_{\text {2deg}}$
), primarily due to the two dimensional electron gas (2DEG) charge density, is modeled. At gate voltages beyond
${V}_{\text {gop}}$
, the model for V-shaped charge density (
${n}_{\text {par}}$
) in
$\beta $
-(AlxGa1−x)2O3 layer is first developed, which is further used to model the secondary current (
${I}_{\text {par}}$
) in this layer. Then, the net drain current (
${I}_{\text {d}}$
) is the summation of both current at different gate voltages. The obtained model for
${I}_{\text {d}}$
demonstrates a good accuracy with different experimental data, thus validating the model. Hence, the proposed models will be very useful for predicting device current characteristics for various applications.