Characterization of Magnetron Sputter CN_x Thin Films

Carbon nitride thin films were deposited at different substrate temperature (ST) by using reactive magnetron sputtering in a pure N₂ discharge, and studied by laser Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometer. The Raman spectra of the films show that I(D)/I(G) decreased with the increase of ST. The D bandposition shifted towards lower frequency, while the G bandposition shifted towards higher frequency as the ST increased. The XPS data exhibit that Nls binding states also depend on ST. The optical band gap of the films is found dropped from 0.22eV to 0.10eV with the increase of ST.