Ion-induced migration of Cu into Si

Abstract

Ion bombardment of Cu-contaminated Si surfaces with either 20-keV Ne+ or 800-eV Ar+ ions leads to enhanced migration of Cu into the bulk of the Si to depths comparable to the projected range of the incident ions. The migration proceeds sufficiently rapidly to prevent sputter removal of submonolayer amounts of Cu even though as much as 100 Å of the substrate is sputtered away. The enhanced migration is probably caused by defect production during the slowing down of the incident ions. The depth distribution of the Cu following Ne+ or Ar+ bombardments was determined from backscattered energy spectra of 280-keV α particles.