Study of the low-pressure chemical-vapor-deposited tungsten-silicon interface: Interfacial fluorine

Journal Article · Wed Mar 15 04:00:00 EST 1989 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.342820· OSTI ID:6445545

Carlisle, J A; Chopra, D R; Dillingham, T R; Gnade, B; Smith, G

Single-crystal silicon <100> substrates uniformly doped at approx. >12 ..cap omega.. cm with boron were deposited with approx.800 A of low-pressure chemically vapor deposited W in a hot-quartz-walled (Anicon) system at a deposition temperature of 300 /sup 0/C. The samples studied include an as-deposited sample and two others which were post-deposition annealed at 600 /sup 0/C in Ar for 15 min each. X-ray photoelectron spectroscopy (XPS) coupled with an Ar/sup +/ ion sputter profiling technique was employed to investigate these structures as a function of depth. Particular emphasis was placed on the depth distribution, content, and chemical state of the fluorine present. Rutherford backscattering spectrometry and x-ray diffraction were used to corroborate the XPS data. Results show that, for the as-deposited and 600 /sup 0/C annealed sample, the maximum concentration of fluorine (0.6--0.8 at. %) is observed, not at the W/Si interface, but rather at the W (H/sub 2/ reduction)/W (Si displacement) interface. For the sample annealed at 850 /sup 0/C, WSi/sub 2/ is formed in the overlayer, and the peak in the F profile corresponds to the position of the WSi/sub 2//Si interface. The maximum concentration of fluorine is reduced by approximately 75% to 0.23 at. % in this sample. From the XPS spectra of the F 1s region, the chemical species of fluorine present in these samples have been identified as WF/sub 6/, WF/sub 5/, and WF/sub 4/.

• Research Organization: Surface Science Laboratory, East Texas State University, Commerce, Texas 75428
• OSTI ID: 6445545
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 65:6; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals &amp; Alloys-- Preparation &amp; Fabrication
360104* -- Metals &amp; Alloys-- Physical Properties
360603 -- Materials-- Properties
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
COATINGS
DEPOSITION
ELECTRICAL PROPERTIES
ELEMENTS
FLUORIDES
FLUORINE
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HALOGENS
IMPURITIES
INTERFACES
METALS
NONMETALS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SEMIMETALS
SILICON
SURFACE COATING
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TUNGSTEN
TUNGSTEN COMPOUNDS
TUNGSTEN FLUORIDES
VAPOR DEPOSITED COATINGS
VERY HIGH TEMPERATURE