Thermal effects on structural properties of diamond-like carbon films prepared by pulsed laser deposition

We have deposited diamond-like carbon (DLC) films by pulsed laser deposition using a KrF excimer laser (248 nm), and have investigated the thermal effects on the structural properties of the DLC films by visible Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The Raman spectra show the G and D peaks near 1580 and 1370 cm−1, respectively. It has been clarified that the intensity of the D peak increases with the deposition temperature, indicating ordering of the a-C films. Fraction of the sp3 bonds in the deposited films, as evaluated from the C1s-XPS peak, decreases with the deposition temperature. The Raman spectra for the films deposited at 150 °C show ordering of a-C by annealing, while the structure of the films deposited at room temperature does not change. When a laser repetition rate is decreased from 20 to 10 Hz, ordering of a-C was observed.