The most common method for the deposition of DLC films is radio freque
ncy PACVD (rf, 13.56 MHz), which is technically difficult and expensiv
e to scale up to industrial dimensions. Alternative methods are direct
current (DC) or medium frequency (mf) plasma excitation which are eas
ier and cheaper to scale up. The deposition of DLC coatings by bipolar
-pulsed direct current PACVD (bp DC PACVD) will be discussed. The expe
riments were carried out in a commercially available plasma nitriding
plant. Adhesion was improved by an intermediate Si-C:H layer using tet
ramethylsilane (Si(CH3)(4)) as a precursor. Methane (CH4) was used for
depositing the DLC films. The mechanical properties of the films such
as hardness, Young's modulus, and wear resistance were studied as a f
unction of the process parameters such as bias current, pressure and m
ethane flow and could be correlated to the reduced parameter J/p(0.5).
The properties thus obtained are comparable with those by rf PACVD. (
C) 1998 Elsevier Science S.A.