PROPERTIES OF A-C/B-H FILMS RELEVANT TO PLASMA SURFACE INTERACTIONS

Thin boron doped carbonaceous films have been deposited on metal alloys (stainless steel, Inconel), graphite and silicon single crystals during the boronization procedures in TEXTOR. The deposits were investigated by X-ray- and electron-diffraction (XRD, RHEED), transmission electron microscopy (TEM), nuclear reaction and backscattering techniques (NRA, ERD, RBS), electron microprobe (EPMA) and surface analysis techniques combined with ion sputtering (AES, XPS, SNMS). The films show a very good adhesion to all the substrates investigated, they are hard, semitransparent, amorphous and homogeneous down to about 3 nm. Colour-thickness correlation implies a refractive index n of about 2.4. The density of the film is almost-equal-to 1.2 g cm-3, the average atomic distance d almost-equal-to 0.23 nm (C-C almost-equal-to 0.25 nm, C-B almost-equal-to 0.15 nm, B-B almost-equal-to 0.31 nm). The energy shift of the B(1s) core level in XPS indicates a covalent character of the B-C bond in the deposit. No indication of B-O bond has been found.