{'fraction_non_alphanumeric': 0.029389017788089715, 'fraction_numerical': 0.0038669760247486465, 'mean_word_length': 5.405940594059406, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
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

We have deposited diamond-like carbon (DLC) films by plasma-enhanced chemical vapor deposition using CH4 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 sp3C–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 sp3-CH3 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.