Development of anti-wear and anti-bacteria TaN-(Ag,Cu) thin films — a review

This paper reviews the past and possible future development of anti-bacteria and anti-wear TaN-(Ag,Cu) nanocomposite thin films. The review starts with the development of TaN-Cu and TaN-Ag nanocomposite thin films which are prepared with co-sputtering followed by rapid thermal annealing (RTA). The incorporation of Ag–Cu atoms simultaneously into TaN film has later shown some advantages over TaN-Ag or TaN-Cu, such as wider bactericidal spectrum, lower annealing temperature, and equally low friction coefficient. Besides describing these advantages, this paper addresses some of the un-solved problems with TaN-(Ag-Cu) thin films, which include a short life time due to fast diffusion of Ag and Cu atoms out on the film surface as well as the adaptive behavior. The paper also discusses about the importance of controlled-releasing the soft metal ions in antibacterial applications. The last part of this paper also discusses briefly the adaptive behavior of these composite films. While the out-diffusion of soft metals from the composite matrix to the surface is essential for the chameleon adaptive behavior to be realized, the controlled diffusion of soft metals is definitely required. In sum, this paper addresses the developing process of anti-bacterial and anti-wear TaN-(Ag,Cu) films, along with some current problems, and provides some possible solutions.