KINETICS OF THE FORMATION OF TITANIUM NITRIDE LAYERS BY RAPID THERMALLOW-PRESSURE CHEMICAL-VAPOR-DEPOSITION FROM TICL4-NH3-H-2

A kinetic study of the titanium nitride growth by low pressure chemica l vapor deposition (LPCVD) from gas-phase TiCl4-NH3-H-2 was carried ou t. Experiments were performed in the temperature range of 600-900 degr ees C and in the total pressure range of 20 to 73 Pa. Partial pressure s ranges were 0.4 to 2.5 Pa for TiCl4, 5 to 43 Pa for NH3, and 13 to 2 8 Pa for H-2. The following law of deposition was obtained r = 2.710(- 5) exp (-9600/T) P-NH2(-0.63) P-TiCl4(+1.27) P-H2(0) A model was devel oped to explain the difference between these results and the published results, and to point out the importance of gas injection configurati on on the experimental reaction orders and on the apparent activation energies. When NH3 (respectively, TiCl4) is injected quite near the su bstrate, this species is strongly adsorbed on the surface, and the ava ilable sites for TiCl4 adsorption (respectively, NH3) are reduced. The n the reaction order with respect to NH3 (respectively, TiCl4) is nega tive, and the rate-determining step is the adsorption of TiCl4 (respec tively, NH3). When these two species are injected far from the substra te, the rate-determining step is the reaction between adsorbed TiCl3 a nd adsorbed NH or NH2.