Publications Details
Thermal stability studies of diamond-like carbon films
Thin films of amorphous carbon/hydrogen, also known as diamond-like carbon or DLC, are of interest as an economical alternative to diamond in a variety of coatings applications. We have investigated the thermal stability of DLC films deposited onto tungsten and aluminum substrates via plasma CVD of methane. These films contain approximately 40 atom % hydrogen, and based on Auger spectra the carbon in the films is estimated to be 60% sp{sup 3} hybridized and 40% sp{sup 2} hybridized. Thermal desorption, Auger, and Raman measurements all indicate that the DLC films are stable to 250--300C. Between 300 and 500C, thermal evolution of hydrogen from the films is accompanied by the conversion of carbon from sp{sup 3} to sp{sup 2} hybridization, and Raman spectra indicate the conversion of the overall film structure from DLC to micro-crystalline graphite or so called ``glassy`` carbon. These results suggest that DLC of this type is potentially useful for applications in which the temperature does not exceed 250C.