A KINETIC-STUDY OF TITANIUM NITRIDE CHEMICAL-VAPOR-DEPOSITION USING NITROGEN, HYDROGEN, AND TITANIUM TETRACHLORIDE

The kinetics of the growth of titanium nitride (TiN) by hot-wall atmospheric pressure chemical vapor deposition (CVD) has been studied using titanium tetrachloride (TiCl4), hydrogen (H-2), and nitrogen (N2) as reactants. The growth rate as a function of reactant concentration at different reaction temperatures is determined. The growth rate dependence in the TiCl4 input concentration changes from a positive to a negative order behavior with increasing reactant concentration, and the observed maximum growth rate shifts to a higher TiCl4 input concentration with increasing reaction temperature. For the growth rate a square root dependence in the N2 concentration is observed in all cases, and for the growth rate a positive order dependence iii the H-2 concentration is observed which changes from 0.5 to 1.5. A reaction model has been proposed based on isothermal Langmuir adsorption behavior with mutual displacement on titanium sites at the surface, and an indirect mutual displacement on nitrogen sites at the surface. This reaction model consists of a set of elementary gas-phase adsorption, and surface reactions which are quasi-equilibrated, and a rate-determining step involving the reaction at the surface between an adsorbed TiCl3 species on a nitrogen site, and an adsorbed NH species on a titanium site. Using this model the experimental and reported growth rate data can be understood as a function of reactant concentration within the temperature region from 1000 to 1273 K.