Formation of nanostructured silicon surfaces by stain etching.

Maha Ayat,Noureddine Gabouze,Samia Belhousse,Luca Boarino,Rabah Boukherroub,Mohamed Kechouane

doi:10.1186/1556-276x-9-482

Abstract

In this work, we report the fabrication of ordered silicon structures by chemical etching of silicon in vanadium oxide (V2O5)/hydrofluoric acid (HF) solution. The effects of the different etching parameters including the solution concentration, temperature, and the presence of metal catalyst film deposition (Pd) on the morphologies and reflective properties of the etched Si surfaces were studied. Scanning electron microscopy (SEM) was carried out to explore the morphologies of the etched surfaces with and without the presence of catalyst. In this case, the attack on the surfaces with a palladium deposit begins by creating uniform circular pores on silicon in which we distinguish the formation of pyramidal structures of silicon. Fourier transform infrared spectroscopy (FTIR) demonstrates that the surfaces are H-terminated. A UV-Vis-NIR spectrophotometer was used to study the reflectance of the structures obtained. A reflectance of 2.21% from the etched Si surfaces in the wavelength range of 400 to 1,000 nm was obtained after 120 min of etching while it is of 4.33% from the Pd/Si surfaces etched for 15 min.

Highlights

In the current semiconductor industry, nanostructures of silicon represent the basic material for the conception of several devices in the field of nanoelectronics [1,2], optoelectronics [3], energy conversion [4,5], energy storage [6,7], andchemical sensors [8,9]
Various methods have been developed to fabricate Si nanostructures such as reactive-ion etching (RIE), electrochemical etching, metal-assisted etching, or stain etching. This last one is an electroless method of forming porous silicon (PSi) in a mixture based on hydrofluoric acid (HF) and an oxidant
For an etching time of 30 min (Figure 1a), the formation of nanoporous silicon layer appears in the form of islands separated by large channels, which resembles the electrochemically etched n-type silicon surface in HF/ethanol solution [12,13]

Summary

Introduction

In the current semiconductor industry, nanostructures of silicon represent the basic material for the conception of several devices in the field of nanoelectronics [1,2], optoelectronics [3], energy conversion [4,5], energy storage [6,7], and (bio)chemical sensors [8,9]. Various methods have been developed to fabricate Si nanostructures such as reactive-ion etching (RIE), electrochemical etching, metal-assisted etching, or stain etching. This last one is an electroless method of forming porous silicon (PSi) in a mixture based on hydrofluoric acid (HF) and an oxidant. The nanostructuring of silicon by stain etching has attracted increasing attention in recent years for several reasons. One of these reasons is that it is an inexpensive method with the ability to control various parameters and can be accomplished in a simple chemical laboratory. The most widely used oxidant is nitric acid (HNO3) which has been investigated in numerous

Methods

Results

Conclusion