title: Elemental distribution in fluorinated amorphous carbon thin films.
abstract: Focused ion beam-secondary ion mass spectrometry (FIB-SIMS) with 20 nm spatial resolution has been used to analyze amorphous fluorinated carbon thin films, deposited by plasma assisted chemical vapor deposition (PACVD), at micro- to nano-scale. Mass spectra and ion imaging of film surface were acquired and the presence and distribution of contaminants were investigated. Surface images show the secondary ion distribution for F(-), CH(-), CF(-). A change in size and topology of fluorine-rich areas is correlated with film hardness and with microstructure transition from diamond-like to polymer-like, as indicated by infrared and Raman spectroscopies. Based on the surface distributions of CF(-) and CH(-) and on the vibrational spectroscopy results, a mechanism of fluorine substitution for hydrogen and an attempt to explain the film structure and microstructure is proposed.
authors.affiliation: Dipartimento di Ingegneria Nucleare, and Centre of Excellence Nano Engineered Materials and Surfaces (NEMAS), Politecnico di Milano, Milan, Italy. alessio.lamperti@polimi.it
authors.forename: A
authors.initials: A
authors.lastname: Lamperti
authors.forename: C E
authors.initials: CE
authors.lastname: Bottani
authors.forename: P M
authors.initials: PM
authors.lastname: Ossi
mesh_terms: D002244:Carbon / Q000032:analysis / Q000737:chemistry*; D005461:Fluorine / Q000032:analysis / Q000737:chemistry*; D008832:Microchemistry / Q000295:instrumentation / Q000379:methods; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D018629:Spectrometry, Mass, Secondary Ion / Q000295:instrumentation* / Q000379:methods; D013499:Surface Properties
chemical_list: D005461:Fluorine; D002244:Carbon