Thermal stability of diamond-like carbon films with added silicon

Diamond-like carbon (DLC) films with added silicon content from 0 to 19.2 a t.% were deposited using r.f. PECVD (radio frequency plasma enhanced chemic al vapor deposition). Fourier transform IR (FTIR) spectrometry, Raman spect rometry and X-ray photoelectron spectrometry (XPS) were used to determine t he structural change of the annealed DLC films in ambient air. By increasin g the annealing temperature the CH, and SI-H groups in the FTIR spectra dec rease because of hydrogen evolution, whereas the intensities of C=O and Si- O peaks increase owing to oxidation. From Raman spectra, the integrated int ensity ratio I-D/I-G of the pure DLC films and the silicon-doped films incr eases at 300 and 400 degrees C, respectively, whereas the observable should er of the D band occurs at 400 and 500 degrees C, respectively, which indic ates that the addition of silicon improves the thermal stability of DLC fil ms. Using XPS analysis, a surface reaction for the annealed films is invest igated. (C) 1999 Elsevier Science S.A. All rights reserved.