Medium-energy ion-scattering study of strained holmium silicide nanoislands grown on silicon (100)

TL;DR

This study uses medium-energy ion scattering to determine the structure of holmium silicide nanoislands on silicon, confirming the tetragonal phase presence and analyzing strain effects, providing insights into their growth and structure.

Contribution

The paper provides the first quantitative MEIS analysis confirming the tetragonal phase of holmium silicide nanoislands on silicon and explores strain effects in large nanoislands.

Findings

Tetragonal phase confirmed over hexagonal in nanoislands.

Hexagonal phase not a precursor at low coverage.

Strain relief effects are consistent with experimental data.

Abstract

We have used medium-energy ion scattering (MEIS) to quantitatively analyze the structure of holmium silicide islands grown on the Si(100) surface. Structure fitting to the experimental data unambiguously shows that the tetragonal silicide phase is present and not the hexagonal phase, which is associated with the growth of nanowires at submonolayer coverages. Islands formed with a lower holmium coverage of 3 ML are also shown to be tetragonal, which suggests that the hexagonal structure is not a low coverage precursor to the growth of the tetragonal phase. MEIS simulations of large nanoislands, which include the effects of lateral strain relief, have been performed and these compare well with the experimental data.