Eur. Phys. J. Appl. Phys. (2015) 72: 10102
https://doi.org/10.1051/epjap/2015150140

Study of the characteristics current-voltage and capacitance-voltage in nitride GaAs Schottky diode

¹ Laboratoire de Micro-électronique Appliquée, Université Djillali Liabès de Sidi Bel Abbés, BP 89, 22000 Sidi Bel Abbés, Algeria
² Laboratoire des Sciences des Matériaux pour l’Electronique et d’Automatique, Université Blaise Pascal de Clermont II, Les Cézeaux, 63177 Aubière, France

^a e-mail: rab_ehi@hotmail.fr

Received: 9 March 2015
Revised: 20 May 2015
Accepted: 27 August 2015
Published online: 30 September 2015

Abstract

This article reports the study of Au/GaN/GaAs Schottky diodes, where the thin GaN film is prepared by nitridation of GaAs substrates with thicknesses of 0.7 and 0.8 nm. The resulting GaN sample with thickness 0.8 nm is then treated with an annealing operation (heating to 620 °C) to improve the current transport. The current-voltage (I-V) and capacitance-voltage (C-V) of the Au/GaN/GaAs structures were investigated at room temperature. In fact, the I-V characteristics show that the annealed sample has low series resistance (R_s) and ideality factor (n) (63 Ω, 2.27 respectively) when compared to the values obtained in the untreated sample (1.83 kΩ, 3.31 respectively). The formation of the GaN layer on the gallium arsenide surface is investigated through calculation of the interface state density N_SS with and without the presence of series resistance R_s. The value of the interface state density N_SS(E) close to the mid-gap was estimated to be in the order of 4.7×10¹² cm^-2 eV^-1 and 1.02× 10¹³ cm^-2 eV^-1 with and without the annealing operation, respectively. However, nitridation with the annealing operation at 620 °C improves the electrical properties of the resultant Schottky diode.