Electron transport mechanism in AlN/b-Ga2O3 heterostructures br

The beta-Ga2O3 has received much attention in the field of power and radio frequency electronics, due to anultrawide bandgap energy of similar to 4.9 eV and a high breakdown field strength of similar to 8 MV/cm (Ponce et al. 2020Phys. Rev. Res.2 033102). The in-plane lattice mismatch of 2.4% between the () plane of beta-Ga2O3 and the(0002) plane of wurtzite AlN is beneficial to the formation of an AlN/beta-Ga2O3 heterostructure (Sun et al. 2017Appl. Phys. Lett.111 162105), which is a potential candidate for beta-Ga2O3-based high electron mobilitytransistors (HEMTs). In this study, the Schrodinger-Poisson equations are solved to calculate the AlN/beta-Ga(2)O(3)conduction band profile and the two-dimensional electron gas(2DEG) sheet density, based on the suppositionthat the 2DEG originates from door-like surface states distributed evenly below the AlN conduction band. Themain scattering mechanisms in AlN/beta-Ga2O3 heterostructures, i.e. the ionized impurity scattering, interfaceroughness scattering, acoustic deformation-potential scattering, and polar optical phonon scattering, areinvestigated by using the Boltzmann transport theory. Besides, the relative importance of different scatteringmechanisms is evaluated. The results show that at room temperature, the 2DEG sheet density increases withthe augment of AlN thickness, and reaches 1.0x1013 cm(-2) at an AlN thickness of 6 nm. With the increase of the2DEG sheet density, the ionized impurity scattering limited mobility increases, but other scattering mechanismslimited mobilities decrease. The interface roughness scattering dominates the mobility at low temperature andmoderate temperature (T < 148 K), and the polar optical phonon scattering dominates the mobility attemperatures above 148 K. The room-temperature mobility is 368.6 cm(2)/(Vmiddots) for the AlN/beta-Ga(2)O(3)heterostructure with an AlN thickness of 6 nm

Automated summary

β-Ga2O3 has attracted much attention in the field of power and radio frequency electronics due to its ultrawide bandgap energy of about 4.9 eV and high breakdown field strength of about 8 MV/cm. The in-plane lattice mismatch between β-Ga2O3 and wurtzite AlN allows for the formation of an AlN/β-Ga2O3 heterostructure, which is a potential candidate for β-Ga2O3-based high electron mobility transistors (HEMTs).