Micro-scratch test study of TiN films grown on silicon by chemical vapor deposition

Abstract

TiN thin films (0.095 μm) were deposited on silicon wafers at 800°C by rapid thermal low-pressure chemical vapor deposition from a TiCl 4+NH 3+H 2 gaseous mixture. Micro-scratches were performed using a system equipped with an optical microscope, an acoustic emission sensor and a friction force sensor. Critical loads were determined to evaluate the adhesion of TiN to the substrate. The influence of the indenter state on the critical load was studied. Scanning electron micrographs, electron probe microanalyses and chemical etching of the film were performed to identify and interpret the damage mechanisms. Experimental results were analyzed using the Weibull statistic. It was shown that small particles of TiN were chipped off and formed a third body, which modified the indenter–film contact and contributed to an increase in the range of the critical load. Models previously proposed in the literature, which allow calculation of the work of adhesion from a critical load, are discussed with respect to the damage mechanisms observed.