Non-destructive characterization of mechanical and structural properties of amorphous diamond-like carbon films

摘要

Amorphous diamond-like carbon (DLC) films show promising properties for wear protectionapplications. Pulsed laser deposition (PLD), laser-induced pulsed vacuum arc deposition (laser-arc)and mass-selected ion beam deposition (MSIBD) are techniques which enable deposition of DLCfilms with the desired properties by providing sufficiently high carbon energy. Two non-destructivemethods were used to determine the properties of films deposited by these three depositiontechniques: (1) ellipsometry, which gives information about the micro-structure through the opticalproperties; and (2) laser-acoustic analysis enabling the measurement of the Young's modulus of thinfilms down to less than 100 nm film thickness. These methods were used to investigate the effect ofthe carbon ion energy and the substrate temperature during deposition on the film quality. A clearcorrelation between the Young's modulus and the optical parameters was found. All three deposition techniques are characterized by a critical substrate temperature abovewhich sp{sup}2 rich films are deposited. The PLD and MSIBD systems have a higher ion energy anda lower deposition rate than the laser-arc system. This is the reason for the higher critical substratetemperature below which sp{sup}3 rich films are formed for PLD and MSIBD compared withlaser-arc.