Formation and properties of Cr-N films by DC reactive sputtering

Cr-N films were deposited using a de reactive sputtering apparatus equipped with an optical emission spectroscope (OES) and the behavior of some speci es excited in the plasma was monitored by OES during sputtering. The films deposited were characterized with respect to the chemical composition, crys tal structure and wear resistance. The results are summarized as follows. (1) The N/Cr ratio monitored by OES increased proportionally with the nitro gen partial pressure. (2) The N/Cr ratio in the deposited films was nearly proportional to the N/ Cr ratio measured by OES during sputtering. Therefore, it may be possible t o control the chemical composition of Cr-N films during sputtering. (3) The N/Cr ratio in the Cr-N films increased continuously, and the struct ure of the films changed from Cr2N through Cr2N + CrN to CrN with increasin g nitrogen partial pressure. (4) Cr2O3 oxide surface layer was observed on the Cr-N films after heating at 800 degreesC for GO mill in air. (5) The crystal structure of CrN films hardly affected the friction coeffic ient at room temperature. The wear resistance of CrN single-phase film was superior to Cr2N single-phase film and Cr2N + CrN dual-phase film at 100 de greesC.