Influence of polymeric underlayers on physical vapor deposited titanium and titanium nitride thin films

Thin films have been widely used and are responsible for many of the technological devices used today. The structural, morphological, mechanical, and tribological properties are important to the film's overall performance. Being able to control these properties can lead to films that are tailored for a specific need. Underlayers can be added to help control the film's properties. For example, Ti underlayers have been used extensively to increase the adhesion of thin films. This study utilized dendrimer underlayers to modify the properties of thin films.;Dendrimers are organic molecules that can form monolayers on a variety of technically interesting substrates. Two different dendrimers were used in this study including a poly(amido amine) (PAMAM) and a n-octadecyltrichlorosilane (OTS) dendrimer. Several generation 4 (G4) PAMAM dendrimers with different functional groups and a G8/NH2 were used in this study.;An additional (10 1¯1) texture was observed with the addition of either the G4 PAMAM or OTS dendrimer underlayers. The films that were deposited without a dendrimer underlayer and on the dipped OTS underlayers had similar hardness values. The films that were deposited on the soaked OTS underlayer had higher hardness values. A G8/NH2 PAMAM underlayer was successfully deposited on a tool steel and stainless steel substrate. The hardness of the TiN films increased with the addition of a G8/NH2 underlayer for the tool steel substrate, but did not increase for the stainless steel substrate. Even thought the dendrimer underlayer exhibited an increase in the mechanical properties of the TiN films on tool steel substrates, the tribological results were not as favorable. The scratch results showed cracking and more damage in the dendrimer mediated films when compared to their dendrimer free counterparts.;The addition of a dendrimer underlayer affected the structural, morphological, mechanical, and tribological properties of the films. Changing the end group functionality of the G4 PAMAM dendrimers affected the grain size, texture, preferred orientation, and the mechanical properties of the films. By carefully selecting the end group functionality, Ti film properties can be tailored to meet the performance desired.