Study of ion beam induced mixing in nano-layered Si/C multilayer structures

TL;DR

This study investigates how ion beam irradiation and thermal treatment induce phase changes and atomic mixing in nano-layered Si/C multilayer structures, revealing formation of different SiC phases.

Contribution

It provides new insights into phase formation and atomic mixing mechanisms in Si/C multilayers under ion irradiation and heat treatment.

Findings

Low fluence irradiation forms hexagonal SiC phase.

High fluence irradiation and annealing produce cubic SiC.

Ion irradiation enhances atomic mixing at interfaces.

Abstract

The effects of ion beam induced atomic mixing and subsequent thermal treatment in Si/C multilayer structures are investigated by use of the technique of grazing incidence X-ray diffraction (GIXRD) and Raman spectroscopy. The [Si (3.0 nm) / C (2.5 nm)]x10 /Si multilayer films were prepared by electron beam evaporation under ultra high vacuum (UHV) environment. The layer thicknesses were measured using in-situ quartz crystal oscillator. These multilayer films were subjected to 40 keV Ar+ ion irradiation with fluences 5E-16 (low fluence) and 1E-17 ions / cm2 (high fluence).The as-prepared and irradiated multilayer samples were annealed at 773 K for one hour. The GIXRD and Raman spectroscopy results reveal the formation of different phases of SiC in these multilayer structures. Deposition induced reactions at the nano-structured interface and subsequent room temperature Ar ion irradiation at low fluence result in formation of the hexagonal SiC phase. High fluence Ar+ ion irradiation and subsequent annealing at 773 K for one hour leads to precipitation of the cubic-SiC phase.