The deposition rate and properties of the deposit in plasma enhanced chemical vapor deposition of TiN

Abstract

Titanium nitride (TiN) films were deposited onto tool steels and cemented carbide cutting tools by plasma enhanced chemical vapor deposition (PECVD) using a gaseous mixture of TiCl4, N2, H2, and Ar in order to find out the effects of the deposition temperature and rf power density on the deposition rate and properties of deposited TiN. The deposition rate and crystallinity of the deposited TiN was affected by the deposition temperature as well as the plasma power density. The deposition rate was decreased with an increase in deposition temperature between 270 and 430 °C. The crystallinity of deposited TiN was improved by an increase in deposition temperature as well as rf power density. Crystalline TiN was obtained above 300 °C and showed a strong crystallographic preferred orientation of 〈200〉. TiN layers deposited by PECVD using TiCl4 as a reactant contained chlorine, the content of which was increased with a decrease in deposition temperature. Oxygen at the interface between the TiN deposited layer and the substrate excluded nitrogen and chlorine. The surface morphology of the deposited TiN is a dome-shaped cluster composed of many fine grains.