Gas-phase chemistry in up-scaled plasma enhanced metal-organic chemical-vapor deposition of TiN and Ti(C, N) on tool steel

Abstract

In this article, the deposition of TiN and Ti(C, N) in a relatively large scale reactor vessel is discussed. Tetrakis(diethylamine)titanium (TDEAT) was used for the deposition of TiN and Ti(C, N) at low temperatures. Favorable gas-phase conditions for deposition of Ti(C, N) in a pulsed direct current plasma have been determined, making use of mass and optical spectroscopy. Decomposition of TDEAT in a pure hydrogen plasma resulted in the favorable cleavage of diethylamine from the precursor but prevents the formation of Ti(C, N) due to the lack of nitrogen and carbon. Addition of N2 to the hydrogen plasma results in the formation of NHx (1⩽x⩽4), opening transamination pathways. Seemingly high quality Ti(C, N) coatings (Hv=1600) were deposited on WN 1.2370 tool steel.