Nanostructure Study of Ti/TiN Multilayers: Effect of the Deposition Temperature

Abstract

In this paper, we report on the growth and the study of Ti/TiN nanometric multilayers. The preparation of these films has been carried out by high vacuum diode r.f. sputtering. Growth was in-situ monitored by kinetic ellipsometry. Deposition temperature was kept to room and low temperature (-120°C) respectively in order to modify the interface properties and consequently to understand the effect of the interfaces on the film’s mechanical properties.

The thickness of each layer was varied from 1 nm to 10 nm and alternately repeated in order to obtain a total thickness of 200 nm. After deposition, films were characterized by means of X-ray diffraction and grazing X-ray reflectometry for structural determination. This study shows that the TiN-Ti boundary is composed of TiN_x, with x going from the nominal nitrogen concentration of the TiN layer to 0. This can be due either to a surface reaction of the incident titanium during the Ti sequence with the nitrogen present at the film surface or to a reaction of nitrogen with the target surface during the TiN sequence.