title: Si1-x Ge x /Si Interface Profiles Measured to Sub-Nanometer Precision Using uleSIMS Energy Sequencing.
abstract: The utility of energy sequencing for extracting an accurate matrix level interface profile using ultra-low energy SIMS (uleSIMS) is reported. Normally incident O2 (+) over an energy range of 0.25-2.5 keV were used to probe the interface between Si0.73Ge0.27/Si, which was also studied using high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). All the SIMS profiles were linearized by taking the well understood matrix effects on ion yield and erosion rate into account. A method based on simultaneous fitting of the SIMS profiles measured at different energies is presented, which allows the intrinsic sample profile to be determined to sub-nanometer precision. Excellent agreement was found between the directly imaged HAADF-STEM interface and that derived from SIMS. Graphical Abstract ᅟ.
authors.affiliation: University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK. r.morris@warwick.ac.uk.|, IMEC, Kapeldreef 75, B-3001, Leuven, Belgium. r.morris@warwick.ac.uk.
authors.forename: R J H
authors.initials: RJ
authors.lastname: Morris
authors.affiliation: University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
authors.forename: T P A
authors.initials: TP
authors.lastname: Hase
authors.affiliation: University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Sanchez
authors.affiliation: University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
authors.forename: G
authors.initials: G
authors.lastname: Rowlands
keywords: SIMS; Si/Si1-x Ge x; Ultra low energy depth profiling