Titanium–silicon–nitride films were grown by metal–organic atomic-layer deposition at 180 °C. When silane was supplied separately in the sequence of a tetrakis(dimethylamido) titanium pulse, silane pulse, and ammonia pulse, the Si content in the deposited films and the deposition thickness per cycle remained almost constant at 18 at.% and 0.22 nm/cycle, even though the silane partial pressure varied from 0.27 to 13.3 Pa. Especially, the Si content dependence is strikingly different from the conventional chemical-vapor deposition. The capacitance–voltage measurement revealed that the Ti–Si–N film prevents the diffusion of Cu up to 800 °C for 60 min. Step coverage was approximately 100% even on the 0.3 mm diam hole with slightly negative slope and 10:1 aspect ratio.