Physics-Based Compact I–V Model for δ-Doped β-(Al_xGa_1−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.