Control of film properties during filtered arc deposition

Abstract

Titanium nitride films may be deposited by filtered arc deposition (FAD) onto heated substrates or by ion assisted arc deposition (IAAD) onto unheated substrates. The stress and microhardness of the deposited films are strongly dependent upon the bias applied to the substrate in FAD. In the case of FAD onto substrates heated to 400 °C, an increasingly negative substrate bias results in a decrease in film compressive stress from 10 to 2 GPa. In the case of nitrogen IAAD onto ambient temperature substrates, the film properties are influenced by the nature of the assisting ion beam, specifically the energy and the relative arrival ratio. The stress ranges from 1 to 7 GPa and the hardness from 26 to 38 GPa. Pronounced effects are also observed in the development of preferred orientation. When the assisting N ion energy is increased from 500 to 1200 eV the orientation changes from (111) to (220). The stress evolution of the arc deposited films may be qualitatively understood in terms of the generalised model for momentum transfer, modified to account for the increased energy of the condensing particles generated by the arc process.