Effects of Substrate Bias Voltage on Structural, Mechanical and Tribological Properties of Diamond-Like Carbon Films Prepared by Plasma-Enhanced Chemical Vapor Deposition Using Methane and Argon Gases

Abstract

We have deposited diamond-like carbon (DLC) films by plasma-enhanced chemical vapor deposition using CH 4 and Ar gases, and have investigated the structure, chemical bonding, adhesion strength, and tribological properties of the deposited films. The film properties have been characterized by visible Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scratch tests, and ball-on-plate friction tests. The fraction of sp 3 C-C and C-H bonds in the deposited films, as estimated from C 1s-XPS peaks, decreased with increasing substrate bias voltage. Raman analysis showed that the structural ordering of the films was induced by increasing the substrate bias voltage. The intensity of the band in the sp 3 -CH 3 stretching in the deposited films decreased with the substrate bias voltage. When the Ar-flow rate was increased, the Ar sputter etching and structural ordering of the films were encouraged. As the bias voltage was increased, the critical load determined by conducting scratch tests and the wear resistance of the films increased.

Effects of Silicon Source Gas and Substrate Bias on the Film Properties of Si-Incorporated Diamond-Like Carbon by Radio-Frequency Plasma-Enhanced Chemical Vapor Deposition

“…We have shown that the deposition rate of DLC films increased with increasing dc bias voltage. 21) This is because positively charged ion species are further accelerated by increasing the negative bias, and the ion flux on the film surfaces increases. When the substrate bias is turned off, the impinging rate of ion species on the film surfaces decreases.…”

Diamond like carbon coatings for potential application in biological implants—a review

“…Solid carbon sources such as graphite or carbon-carbon composites are used for coatings with low or no hydrogen. The ratio of sp 2 and sp 3 bonds is determined during coating synthesis by the impact energy of the depositing molecules, which is dictated by the bias voltage of the deposition [15]. At very low energies a non-DLC carbon polymer forms.…”

Effects of frequency of pulsed substrate bias on structure and properties of silicon-doped diamond-like carbon films by plasma deposition

“…We have shown that the deposition rate of DLC films increased with increasing dc bias voltage [14]. This is because positively charged ion species are…”

“…The C-O bonding component is attributed to some residual contaminations formed on the surfaces due to air exposure [19]. It is known that the binding energy of C-H is 284.9-285.5 eV [14,20,21]. It is difficult to separate the sp 3 to occur by the decomposition of CH 4 molecules because CH 2 has a higher sticking coefficient than CH 3 [15].…”