Atomic Layer Deposition of Aluminum Nitride and Oxynitride on Silicon Using Tris(dimethylamido)aluminum, Ammonia, and Water

Thin films of aluminum nitride and oxynitride were deposited by atomic layer deposition (ALD) in the temperature range from 170 to 290 degrees C (optimal deposition temperature 200-230 degrees C). Tris(dimethylamido) aluminum and ammonia were used as precursors for the atomic layer deposition of aluminum nitride (AlN). The average AlN film thickness per ALD cycle (deposition rate) at 200 degrees C was 0.8 angstrom. Films were deposited on a silicon <100> substracte with a native oxide layer. The N/Al atomic concentration ratio in the obtained films was 1.3. Aluminum oxynitride films obtained by periodical dose of water vapor in the course of atomic layer deposition of AlN at 200 degrees C. The composition of the deposited oxynitride films was Al0.5O0.43N0.07.