Eur. Phys. J. Plus (2017) 132: 119
https://doi.org/10.1140/epjp/i2017-11383-2

Regular Article

A novel passivation process of silicon nanowires by a low-cost PECVD technique for deposition of hydrogenated silicon nitride using SiH₄ and N₂ as precursor gases

¹ Université de Tunis El Manar, Faculté des Sciences Mathématiques, Physiques et Naturelles de Tunis, 2092, Tunis, Tunisia
² LAboratoire des Nanomatériaux et des Systèmes pour les Energies Renouvelables (LANSER), Centre de Recherche et des Technologies de l’Energie (CRTEn), BP 95, 2050, Hammam-Lif, Tunisia
³ Nanophotonics Technology Center (NTC), Universidad Politécnica de Valencia (UPV), 46022, Valencia, Spain

^* e-mail: lamia.bouaziz89@gmail.com

Received: 27 September 2016
Accepted: 30 January 2017
Published online: 8 March 2017

Abstract

In this work, a different SiN_x passivation process of silicon nanowires has been opted for the deposition of a hydrogenated silicon nitride (SiN_x:H) by a low-cost plasma enhanced chemical vapor deposition (PECVD) using silane ( SiH₄ and nitrogen ( N₂ as reactive gases. This study is focused on the effect of the gas flow ratio on chemical composition, morphological, optical and optoelectronic properties of silicon nanowires. The existence of Si-N and Si-H bonds was proven by the Fourier transmission infrared (FTIR) spectrum. Morphological structures were shown by scanning electron microscopy (SEM), and the roughness was investigated by atomic force microscopy (AFM). A low reflectivity less than 6% in the wavelength range 250-1200nm has been shown by UV-visible spectroscopy. Furthermore, the thickness and the refractive index of the passivation layer is determined by ellipsometry measurements. As a result, an improvement in minority carrier lifetime has been obtained by reducing surface recombination of silicon nanowires.