Controlled Growth of TaN, Ta₃N₅, and TaOxNy Thin Films by Atomic Layer Deposition

TaN, Ta 3 N 5, and TaO x N y films were deposited by the atomic layer deposition technique. The alternate surface reactions between TaCl 5 and NH 3 resulted in Ta 3 N 5 films, but when elemental zinc, serving as an additional reducing agent, was supplied on the substrates between the TaCl 5 and NH 3 pulses, TaN with a resistivity of 9 × 10 - 4 Ω cm was obtained. TaO x N y films were grown by depositing first thin Ta 3 N 5 layers which were then partially oxidized by single water pulses. By varying the number of the Ta 3 N 5 deposition cycles between the water pulses, the oxygen-to-nitrogen ratio of the films was controlled. The permittivity of the TaO x N y films was around 30 which is somewhat higher than that of Ta 2 O 5 .