Growth of aluminum nitride films by plasma-enhanced atomic layer deposition

Aluminum nitride films have been grown by plasma-enhanced atomic layer deposition under self-limiting growth and CVD-like conditions. The films have been characterized by IR spectroscopy, ellipsometry, and Auger exposure spectroscopy. We have examined the influence of the deposition temperature, the reactor purge time after exposure to trimethylaluminum vapor, and the plasma exposure time on the growth rate and composition of the films. Under the deposition conditions studied, the growth rate ranged from 0.1 to 0.26 nm per cycle and the refractive index of the films was 1.52 to 1.98. We obtained films with an aluminum to nitrogen atomic ratio near unity.