Title :
Modeling and experimental results for C(V) in an abrupt isotype n Al0.5Ga0.5As/GaAs heterojunction
Author :
Serra, Antonio Cruz ; Santos, Humberto Abreu ; Marty, Antoine ; Bailbe, Jean Pierre ; Rey, Gérard
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Tech. Univ. of Lisbon, Portugal
fDate :
2/1/1993 12:00:00 AM
Abstract :
The differential capacitance C of an abrupt isotype n Al0.5 Ga0.5As/GaAs heterojunction has been modeled by directly calculating the dependence of the space charge on the voltage V at its terminals. The electron charge distribution was calculated considering the 2-D electron gas by simultaneously solving the Schrodinger and the Poisson equations, DX centers included. Results from this model predict an asymmetric bell-shape dependence of C on V, with a maximum near the contact potential, and are in good agreement with experiment. This further provides experimental evidence of Γ-Γ and X-X valley coupling for electrons traveling across the heterojunction. For voltage values not too close to the contact potential, it was possible to find a simple method, based on a total depletion, that gives a good fit to experiment
Keywords :
III-V semiconductors; aluminium compounds; capacitance; contact potential; gallium arsenide; interface electron states; semiconductor junctions; space charge; two-dimensional electron gas; 2D electron gas; C-V characteristics; DX centers; Gamma-Gamma valley coupling; Poisson equations; Schrodinger equation; X-X valley coupling; abrupt isotype Al0.5Ga0.5As-GaAs heterojunction; asymmetric bell-shape dependence; contact potential; differential capacitance; electron charge distribution; model; space charge; Artificial intelligence; Capacitance; Electrons; Gallium arsenide; Heterojunctions; Poisson equations; Predictive models; Space charge; Superlattices; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
