TITLE:
Fabrication of Tungsten Carbide Films by Filtered Pulse Arc Deposition with Cemented Tungsten Carbide Cathodes
AUTHORS:
Ryo Isono, Tsuyoshi Tanimoto, Yushi Iijima, Toru Harigai, Yoshiyuki Suda, Hirofumi Takikawa, Satoru Kaneko
KEYWORDS:
Cemented Tungsten Carbide Cathode, Thin Film, Filtered Pulse Arc Deposition
JOURNAL NAME:
Materials Sciences and Applications,
Vol.8 No.13,
December
8,
2017
ABSTRACT: Tungsten carbide films (W-C films) were fabricated
on silicon substrates by using the filtered pulse arc deposition (FPAD) method.
Two types of cemented tungsten carbide (WC) were used as cathode, one
containing Co and the other Ti, which were used as binders for forming the
cathode shape. The films were fabricated by varying the pulse arc current and
substrate bias voltage. The discharge, deposition and film properties were
investigated under these deposition conditions. The cathode wear amount when
using WC-Co (WC cathode containing Co) was found to be smaller than that
measured when WC-Ti (WC cathode containing Ti) was used. The W-C film thickness
was approximately 30 - 40 nm
under all conditions, except when the pulse arc current was 50 A and the film
thickness, was approximately 10 nm. Compared to the WC-Ti, the consumption of
cathode material is suppressed in the WC-Co, indicating that the efficiency for
film preparation of the latter is good. From the X-ray diffraction analysis,
the crystalline phase of W-C films fabricated using WC-Co and WC-Ti were
observed as W2C and WC1-x, respectively, indicating that
different crystalline phases could be fabricated using different cathodes. From
the X-ray photoelectron spectroscopy analysis, the oxidation layer formed by
air exposure was observed to exclusively exist on the W-C film surface.
Moreover, almost all oxygen in the oxidation layer bonded with tungsten.