Investigation of current-voltage characteristics of Ni/GaN Schottky barrier diodes for potential hemt applications

Abstract

In the present work, the I-V characteristics of Ni/GaN Schottky diodes have been studied. The Schottky diodes, having different sizes using Ni/Au and ohmic contacts using Ti/Al/Ni/Au were made on n-GaN. The GaN was epitaxially grown on c-plane sapphire by metal organic chemical vapor deposition (MOCVD) technique and had a thickness of about 3.7 μm. The calculated ideality factor and barrier height from current-voltage (I-V) characteristics (at 300 K) for two GaN Schottky diodes were close to ~1.3 and ~ 0.8 eV respectively. A high reverse leakage current in the order of 10 – 4A/cm2 (at – 1 V) was observed in both diodes. A careful analysis of forward bias I-V characteristics showed very high series resistance and calculation for ideality factor indicated presence of other current transport mechanism apart from thermionic model at room temperature. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/22021