An accurate method of simulating nonequilibrium gate current and sheet-carrier concentration in AlGaAs/GaAs HEMT structures is reported. The calculation is based upon self-consistent solving of Schrodinger's equation, Poisson's equation and continuity equations. A concept for three-dimensional electrons accompanied by two-dimensional electrons in a quantum well at a heterointerface makes it possible to solve the continuity equation at the quantum-well region. Thermionic emission theory is applied for the current expression across an abrupt heterointerface. As a result, there is a certain voltage drop across the heterointerface, which helps prevent the creation of the neutral region in the AlGaAs layer. Simulated results explain measured gate-current and channel-conductance characteristics of a HEMT structure. >
['C. Takano', 'Zhiping Yu', 'Robert W. Dutton']
A nonequilibrium one-dimensional quantum-mechanical simulation for AlGaAs/GaAs HEMT structures