A method for forming a strained SiN film and a semiconductor device
containing the strained SiN film. The method includes exposing the
substrate to a gas including a silicon precursor, exposing the substrate
to a gas containing a nitrogen precursor activated by a plasma source at
a first level of plasma power and configured to react with the silicon
precursor with a first reactivity characteristic, and exposing the
substrate to a gas containing the nitrogen precursor activated by the
plasma source at a second level of plasma power different from the first
level and configured to react with the silicon precursor with a second
reactivity characteristic such that a property of the silicon nitride
film formed on the substrate changes to provide the strained silicon
nitride film.