Formation of ordered arrays of Ag nanowires and nanodots on Si(5 5 7) surface

TL;DR

This study investigates the formation of ordered silver nanowire and nanodot arrays on Si(5 5 7) surfaces, revealing how oxygen adsorption influences nanostructure shape and arrangement during ultra-high vacuum deposition.

Contribution

It demonstrates the controlled formation of Ag nanostructures on Si(5 5 7) surfaces and shows the impact of residual oxygen on their morphology.

Findings

Oxygen adsorption affects Ag nanostructure shape.

Ag nanowires align along steps.

Nanodots form in lines parallel to steps.

Abstract

The ordered arrays of Ag nanowires and nanodots have been grown in ultra-high vacuum on the Si(5 5 7) surface containing regular steps of three bilayer height. Formation of Ag nanostructures have been studied by scanning tunneling microscopy, low energy electron diffraction and Auger electron spectroscopy at room temperature. It was shown that a sample exposure in the vacuum before Ag growth affects the shape of the forming Ag islands. This effect is caused by oxygen adsorption on the silicon surface from the residual atmosphere in the vacuum chamber. When Ag is deposited on the clean silicon surface the islands, overlapping several (1 1 1) neighboring terraces, form. The arrays of silver nanowires elongated along steps and silver nanodots, arranged in lines parallel to the steps, can be formed on the Si(5 5 7) surface depending on the amount of adsorbed oxygen.