Study and modeling of the transport mechanism in a semi insulating GaAs Schottky diode

The current through a metal–semiconductor junction is mainly due to the majority carriers. Three distinctly different mechanisms exist in a Schottky diode: diffusion of carriers from the semiconductor into the metal, thermionic emission–diffusion (TED) of carriers across the Schottky barrier and quantum–mechanical tunneling through the barrier. The insulating layer converts the MS device in an MIS device and has a strong influence on its current–voltage (I–V) and the parameters of a Schottky barrier from 3.7 to 15 eV. There are several possible reasons for the error that causes a deviation of the ideal behavior of Schottky diodes with and without an interfacial insulator layer. These include the particular distribution of interface states, the series resistance, bias voltage and temperature. The GaAs and its large concentration values of trap centers will participate in an increase of the process of thermionic electrons and holes, which will in turn the IV characteristic of the diode, and an overflow maximum value [NT = 3 × 1020] is obtained. The I–V characteristics of Schottky diodes are in the hypothesis of a parabolic summit.

The I–V characteristics of Schottky diodes in the hypothesis of a parabolic summit.Figure optionsDownload as PowerPoint slideHighlights
► The simulator designed and is denoted to the study of devices with small geometry.
► The I–V of Schottky diodes in the hypothesis of a parabolic summit of the gate of potential.
► The I–V of Schottky diodes with an interfacial insulator layer are studied by numerical simulation.
► The traps or deep centers in a semiconductor drives to a disruption of the characteristic I(V).
► The JTED remained steady for small values beyond this temperature the current progresses.