Ironsilicide formation by high temperature codeposition of Fe-2Si with different thicknesses on Si (111)

TL;DR

This study investigates the formation of iron silicides on Si (111) surfaces at high temperature through co-deposition of Fe and Si, revealing phase variations dependent on film thickness.

Contribution

It demonstrates how different silicide phases form at various film thicknesses during high-temperature co-deposition on Si (111).

Findings

Low thickness yields ε-FeSi and metastable FeSi phases.

Thicker films (12 nm) produce stable β-FeSi₂.

Phase formation depends on film thickness.

Abstract

Fe and 2Si were co-deposited on Si (111) surface at 853 K. The formation of silicides was investigated by Mossbauer spectroscopy and electron microscopy. Depending on the thickness of the deposited films different phases were formed. At low thickness, stable $\epsilon$-FeSi (B20) and metastable [CsCl]-Fe$_{1-x}$Si (B2) phases were observed. In the latter case, because of the presence of Fe vacancies in the lattice the local symmetry around the iron components was lower than cubic. At larger (12 nm) deposited thickness, stable $\beta$-FeSi$_2$ has been formed.