Influence of process parameters on the growth of TiN in different sized plasma-assisted chemical vapor deposition reactors

TiN layers were deposited by pulsed d.c. plasma in an Ar-H2-N2-TiCl4 mixture on substrates positioned on the cathode in different-sized plasma-assisted chemical vapor deposition reactors. We investigated the influence of different N2-H2 gas flow and of the pause time on the layer properties in relation to the reactor volume. Scanning electron microscopy measurements show that the growth rate increases with increasing N2/H2 gas flow ratio, whereas an influence from the total gas flow cannot be found. The TiN layers are nearly stoichiometric, except for low N2 gas flows. Grazing incidence X-ray diffractometry measurements reveal a transition from X-ray amorphous to crystalline TiN with higher N2/H2 gas flow ratios. However, a preferred orientation was not observed. The decrease of the pause time at pulses with the same current height and on-time lead to a strong decrease of the effective growth rate. We assume that a sufficient pause length is necessary for a stable growth of TiN layers.