Multilayer PECVD Si-C-N Films

Abrasive wear resistance, optoelectronic and mechanical properties of multilayer (ML) and monolayer (SL) silicon carbide nitride (Si-C-N) films were investigated. The Si-C-N films were prepared by plasma to enhance chemical vapor deposition using a mixture of hexamethyldisilazane vapor, hydrogen, and nitrogen. Two types of the SL films were deposited at high and low substrate biases of -250 V and -5 V. The films demonstrate hardness similar to 33 GPa and similar to 13 GPa, respectively. The ML films represent the sequence of hard and soft layers. The correlation between the deposition time of a single layer (t(D)) and wear resistance was revealed: the smaller the deposition time, the higher the wear resistance is. The optoelectronic properties of the films were found to be insensitive to t(D). All the ML films have a lower energy gap (2.18-2.35 eV) than the SL films (4.1-2.42 eV). A strong quenching of photoluminescence was observed for the ML films.