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For the first time, a core drain current model based on surface potential without any implicit functions is developed for beta-phase gallium oxide (β-Ga2O3) power metal-oxide-semiconductor field-effect transistors (MOSFETs). The surface potential solution is analytically deduced by solving the Poisson equation with appropriate simplification assumptions in accumulation, partial-depletion, and full-depletion modes. Then, the drain current expression is analytically derived from the Pao–Sah integral as a function of the mobile charge density obtained from the surface potential at the source and drain terminals. In addition, nonlinear resistors in the source/drain access region are considered. It continuously predicts the characteristics of β-Ga2O3 power MOSFETs in all operation modes, including accumulation mode, partial-depletion mode, and full-depletion mode. Furthermore, the validity of the model is verified by comparing the results of the model with the numerical simulations carried out with the technology computer-aided design (TCAD) tool ATLAS Device Simulator from Silvaco. Good agreement between the proposed model and TCAD simulations is shown for β-Ga2O3 power MOSFETs with different intrinsic channel lengths, channel doping concentrations, and channel thicknesses. Ultimately, the Gummel symmetry test and the harmonic balance simulation test are performed to validate the model's robustness and convergence. [ABSTRACT FROM AUTHOR]

Effective control of magnetic anisotropy is important for developing spintronic devices. In this work, we performed a case study of stacking periods (N)-mediated reorientation of lateral magnetic anisotropy in ultrathin La0.67Ca0.33MnO3/SrRuO3 superlattices. As N increases from 1 to 15, the magnetic easy-axis switches from the orthorhombic [010] to [100]-axis. The maximum anisotropy constant of the superlattice (SL) (N = 15) reaches −1.83 × 105 erg/cm3. X-ray absorption spectroscopy and x-ray linear dichroism further suggest that the observed changes in lateral magnetic anisotropy are driven by in-plane orbital polarization. For SLs with small N, anisotropic strain-induced orbital polarization along the b-axis can result in the [010]-oriented magnetic easy axis. For SLs with large N, the dimension crossover from 2-dimension to 3-dimension could enhance the hybridization of Ru t2g and Mn d x 2 − y 2 orbitals, which can compete with the strain effect and switch the magnetic easy axis to [100]. Our results suggest a potential strategy for engineering magnetic anisotropy through the cooperation of strain engineering and interfacial orbital engineering. [ABSTRACT FROM AUTHOR]