Abstract
The formation of oxynitride films less than 2.0 nm by using oxygen and nitrogen radicals produced by an electron cyclotron resonance plasma in an ultrahigh-vacuum system has been studied. We found that the N concentration can be controlled at values up to 15% and that, although the interface roughness tends to increase with increasing N concentration, supplying oxygen and nitrogen radicals simultaneously decreases the roughness of the film and increases its nitrogen concentration (N: 12.1%, root mean square: 0.12 nm). We also could easily control the nitrogen profile in the oxynitride less than 2.0-nm-thick by using different processing sequences.