Dry etching of titanium nitride thin films in CF4–O2 plasmas

The dry etching of titanium nitride has been studied in fluorine containing glow discharges. Untreated samples are covered by an oxidized layer of titanium oxide and/or oxynitride. X-ray photoelectron spectroscopy cannot be utilized to clarify the nature of these species that strongly influence surface reactivity. In agreement with some published data, it has been found that the component of the N 1s signal at low binding energy is due to interstitial nitrogen atoms and not to substoichiometric nitrides. An analysis of the effect of temperature and bias voltage variation is reported as well as the changes of surface composition due to the plasma action. Comparisons with the reactivity of metallic titanium are also discussed.