Study of the Mechanical Properties of Diamond-like Carbon Thin Films Deposited in Single and Dual Frequency Capacitive Discharges
| Authors | |
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| Year of publication | 2008 |
| Type | Article in Proceedings |
| Conference | 2nd Central European Symposium on Plasma Chemistry - Book of Extended Abstracts |
| MU Faculty or unit | |
| Citation | |
| Field | Plasma physics |
| Description | Nanostructured diamond-like carbon coatings were deposited on several different substrate materials (silicon, glass, polycarbonate and steel) in single (13.56 MHz) and dual capacitive r.f. discharges (LF=100-300kHz, HF =13.56 MHz). The objective of our study was to find the optimum combination of the high and low frequency (continuous or pulsed) excitation enabling to cover uneven substrate surfaces and significant lowering of the internal stress in films. The mechanical properties of prepared coatings (e.g. hardness, elastic modulus, fracture toughness, coating/substrate adhesion etc.) were studied using several different types of indentation methods: the depth sensing indentation test (DSI) based on analysis of the loading/unloading hysteresis, the continuous stiffness measurement (CSM) method and the dynamic mechanical analysis (DMA, UNHT – CSM Instruments). The effect of intrinsic stress on the coating properties was investigated. Analysis of the evolved crack morphology was made by means of optical microscopy , scanning electron microscopy (SEM) and atomic force microscopy (AFM). The principal new finding concerns the fracture toughness of the film and the interfacial adhesion. The films can sustain compression strains without debonding or spalling. The effect of intrinsic stress on the coating properties was investigated. On the basis of above described investigation nanocomposite coatings with enhanced mechanical properties (high hardness, adhesion, fracture toughness, low intrinsic stress) were prepared. |
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