An optimal nickel difluoride (NiF2) film-formation technology has been
investigated for electroless Ni-P deposited films, where highly sensi
tive electrochemical anodic polarization measurement and thin-film x-r
ay diffraction (XRD) amorphous structure as deposited which is convert
ed into crystalline structure such as nickel phosphides (Ni2P or Ni3P)
with heating, this is undesirable for the formation of homogeneous fl
uorine passivation films. Low incident angle XRD allows us to determin
e the fluoridation conditions where the NiF2 films little include thes
e nickel phosphides crystals. Further, anodic polarization measurement
curves support the film-formation conditions (temperature, fluorine c
oncentration) of nickel difluoride and the effect of heat-treatment af
ter fluoridation. The low fluoridation temperature at ca. 300-degrees-
C is not sufficient and low fluorine concentration is also unfavorable
for the fluoridation of the electroless Ni-P deposited films. We cond
ucted several evaluations such as corrosion resistance, outgassing cha
racteristics, and plasma resistance using the nickel difluoride films
formed by the most favourable condition.