Chemical vapor deposition of Ti-Si-N films with alternating source supply

Titanium-silicon-nitride films were grown by atomic layer deposition using an alternating supply of tetrakis(dimethylamido)titanium (TDMAT), silane,: and ammonia, at substrate temperature of 180 degrees C. The supply of a reactant was followed by a purge with inert gas before introducing another reactant onto the substrate in order to prevent gas-phase reactions. In one set of experiments the reactants were supplied separately in the sequence of TDMAT, silane, and ammonia. The Si content of the films remained constant at 18 at.%, and the film growth rate varied little from 0.24 nm per reactant-supply-cycle, even though silane partial pressure varied from 0.002 to 0.1 torr. In the other set of experiments silane and ammonia were simultaneously supplied in the sequence of TDMAT and silane/ammonia. The Si content varied from 3 to 23 at.% as the silane-to-ammonia ratio varied from 0.01 to 10. Atomic layer deposition of Ti-Si-N films allows the precise control of Si content as well as film thickness.