DLC FILMS DEPOSITED BY BIPOLAR PULSED DC PACVD

For engineering applications, diamond-like carbon films (DLC) are the most suitable coatings, when high wear-resistance and low friction is needed. One problem is their very poor adhesion to steel substrates wh en no intermediate layer is supplied. The most common method for depos iting DLC-films is a plasma activated chemical vapour deposition proce ss with radio frequency (rf PACVD, 13.56 MHz), which is technically di fficult and expensive to scale up to industrial dimensions. The FhG-IS T is testing different methods for plasma excitation, e.g. DC plasmas or hollow cathode excitation. It is assumed that these methods are eas ier and cheaper to scale up. In this paper the deposition of DLC coati ngs by bipolar-pulsed direct current PACVD (bip DC PACVD) is presented . 100Cr6 steel was used as substrate material. The experiments were ca rried out in a commercially available plasma nitriding plant. The adhe sion was improved by an intermediate Si-C:H layer with tetramethylsila ne (Si(CH3)(4)) as a precursor. Methane (CH4) was used for depositing the DLC films. The properties, thus obtained, are comparable to those of DLC films deposited by rf PACVD. (C) 1998 Published by Elsevier Sci ence S.A.