J. Phys. IV France 09 (1999) Pr8-605-Pr8-612
Optimisation of the MOCVD of Ti(C, N) in a pulsed H2 - N2 plasma by gas-phase analysisJ. P.A.M. Driessen1, 2, A. D. Kuypers1 and J. Schoonman2
1 TNO Institute of Applied Physics, Department of Materials Chemistry & Coatings, Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
2 Laboratory for Inorganic Chemistry, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
Favourable gas-phase conditions for the deposition of Ti(C,N) in a large scale reactor vessel have been determined by a mass spectroscopic study of the activation of tetrakis(dimethylamino)titanium (TDMAT) and tetrakis(diethylamino)titanium (TDEAT) in a mixed H2-N2 pulsed DC plasma. Activated hydrogen seemingly attacks the M-L bond. At least part of the ligands are stripped from the Ti atom. This prevents hydrocarbon incorporation in the coating. However, no nitrogen remains available for the formation of TiN. Addition of N2 to a H2 plasma seems to result in transamination. Transamination by NHx (1≤x≤4) in a H2-N2 plasma appears to be a very attractive mechanism for cleavage of ligands and nitrogen supply at low temperatures. Deposition under preferred conditions produced bronze adherent coatings. The hardness varied between 1600 and 2300 kgf/mm2 on stainless steel and tungsten carbide. The coatings are very ductile and might improve wear resistance of tools in non-lubricating forging processes.
© EDP Sciences 1999