Schottky barrier inhomogeneities at the interface of different epitaxial layer thicknesses of n-GaAs/Ti/Au/Si: Al0.33Ga0.67As

Abstract

The effects of an epitaxial layer on the rectifying behavior of n-GaAs/Ti/Au/Si:Al0.33Ga0.67 As diodes have been examined through the inhomogeneity model on n+-GaAs substrate with orientation. The electrical properties and conduction mechanism of these materials were understood through theoretical models. The inhomogeneity model was used to electrical behavior of these diodes was explained. The barrier height inhomogeneity model reveals a 13% and 15% barrier height inhomogeneity in N1 and N2 Schottky diodes, respectively. The ideal thermionic emission behavior increases the ideality factors and reduces barrier heights. Within the entire temperature range, the effective Schottky barrier for a thin epitaxial layer was higher. Such results depicted the presence of defects in the thick layer, which decreased the barrier height and ultimately degraded diode performance. The thermionic emission theory along with Gaussian distribution of barrier heights is explained by the temperature dependence of the forward bias current-voltage-temperature (I-V-T) features.