Structural and bonding properties of carbon nitride films prepared by dc magnetron sputtering

Amorphous carbon nitride (CN) films have been deposited onto Si(100) substr ates by reactive sputtering of a graphite target in a purl N-2 ambient. A m odified cylindrical DC magnetron plasma was used as a sputter deposition so urce and the effects of substrate DC self-bias voltage caused by RF bias on film properties were investigated. X-ray photoelectron spectroscopy (XPS) spectra of N Is and C Is electron confirmed the existence of multiple bondi ng states for carbon and nitrogen (sp(2) and sp(3)) in the film. Fourier tr ansform infrared (FTIR) spectroscopy studies showed a systematic variation in spectra by a DC self-bias voltage. Raman spectra revealed two peaks corr esponding to G band (1580 cm(-1)) and D band(1370 cm(-1)). The ratio of int egrated intensities of D and G band (I-D/I-G) increased with DC self-bias v oltage, suggesting increased disorder by the ion bombardment on growing fil m. Variation in the morphology of CNx films deposited at different bias vol tage was examined by scanning electron microscopy (SEM). (C) 1999 Elsevier Science S.A. All rights reserved.