A study of current‐voltage and capacitance‐voltage characteristics of Au/n‐GaAs and Au/GaN/n‐GaAs Schottky diodes in wide temperature range

Abstract

AbstractIn this paper, a study of the effect of thin GaN interfacial layer (1 nm) on the electrical behavior of Au/n‐GaAs structure is investigated in wide temperature range 100 to 400 K, using Silvaco‐Atlas simulator. As a result, from I‐V characteristics, the series resistance R s is increased with decreasing temperature for Au/GaN/n‐GaAs structure, while it is remained almost constant for Au/n‐GaAs structure. The saturation current I s is decreased with decreasing temperature for both structures. The ideality factor n is increased, and the barrier height is decreased when temperature decreases, with important variation for Au/GaN/n‐GaAs structure. This abnormal behavior is due to the deviation of the dominant conduction mechanisms, from the thermionic emission TE current to the thermionic field emission TFE and the field emission FE. As well as, the Au/n‐GaAs structure shows a homogeneous of barrier height, while it is inhomogeneous for Au/GaN/n‐GaAs structure. In addition, from C‐V characteristics, the potential diffusion V d and the barrier height are increased with decreasing temperature for both structures, conversely to those obtained from the TE theory. These results confirm the deviation of the TE current to the TFE and FE currents with decreasing temperature for the Au/n‐GaAs and Au/GaN/n‐GaAs Schottky diodes.