Disorder induced interface states and their influence on the AI/Ge nanowires Schottky devices

Journal of Applied Physics Volume: 114 Issue: 24 Published: 2013

(a) Temperature-dependent resistance curve revealing a semiconductor behaviour and the corresponding fitting for the VRH mechanism (inset). (b) Current-voltage curves for different temperatures used to determine the Schottky barrier height, using the back-to-back model. The fitting for 400 K is shown in the inset. (c) The equivalent electrical circuit for the back-to-back model. (d) Sketch of the experimental device with aluminium contacts over Ge nanowires layer on Si/SiO2 substrate.

Writers: R. A. Simon, H. Kamimura, O. M. Berengue, E. R. Leite, A. J. Chiquito

Keywords: nanowires; devices

Abstract: It has been demonstrated that the presence of oxide monolayers in semiconductor surfaces alters the electronic potential at surfaces and, consequently, can drastically affect the electronic transport features of a practical device such as a field effect transistor. In this work experimental and theoretical approaches to characterize Al/germanium nanowire Schottky devices by using samples covered with a thin oxide layer (2 nm width) were explored. It was also demonstrated that the oxide layer on Ge causes a weak dependence of the metal work function on Schottky barrier heights indicating the presence of Fermi level pinning. From theoretical calculations the pinning factor S was estimated to range between 0.52 and 0.89, indicating a weak Fermi level pinning which is induced by the presence of charge localization at all nanowires’ surface coming from interface states.

See PDF: Disorder induced interface states and their influence on the Al-Ge nanowires Schottky devices

DOI: 10.1063/1.4857035

Rose Portasio
Sobre Rose Portasio 131 Artigos
Assessora Administrativa no LIEC - IQ/Unesp