Abstract :
A threshold-voltage-based 2-D analytical model for the current-voltage characteristics of the AlGaN/GaN modulation-doped field-effect transistors (MODFETs) is presented. In this paper, the conventional charge-control model is improved by employing the Robin boundary condition when solving the 1-D Schrodinger equation in the low longitudinal-field region and introducing an adjustable eigenvalue during the solution of the 2-D Poisson´s equation in the velocity-saturation region. A modified Polyakov-Schwierz mobility model, as well s a low-field mobility model, has been developed. In addition, the nonlinear polarization effects at the AlGaN/GaN interface and the parasitic source/drain resistances are incorporated. Our model predicts the drain current of a second-order continuity, and both the transconductance and output conductance can be determined analytically. We validate the model with experimental data for and MODFETs, respectively, and obtained good agreements.
Keywords :
Poisson equation; Schrodinger equation; carrier mobility; eigenvalues and eigenfunctions; high electron mobility transistors; semiconductor device models; 1D Schrodinger equation; 2D Poisson equation; 2D analytical model; AlGaN-GaN; MODFET; Robin boundary condition; adjustable eigenvalue; current-voltage characteristics; drain current; improved charge-control model; low-field mobility model; modified Polyakov-Schwierz mobility model; modulation-doped field-effect transistors; nonlinear polarization effects; parasitic source/drain resistances; second-order continuity; transconductance property; velocity-saturation region; Aluminum gallium nitride; Analytical models; Boundary conditions; Current-voltage characteristics; Epitaxial layers; FETs; Gallium nitride; HEMTs; MODFETs; Transconductance; AlGaN/GaN; MODFETs; compact model; sheet carrier concentration;
