A dielectric film containing atomic layer deposited HfSiON and a method of
fabricating such a dielectric film produce a reliable dielectric layer
having an equivalent oxide thickness thinner than attainable using
SiO.sub.2. The HfSiON layer thickness is controlled by repeating for a
number of cycles a sequence including pulsing a hafnium containing
precursor into a reaction chamber, pulsing an oxygen containing precursor
into the reaction chamber, pulsing a silicon containing precursor into
the reaction chamber, and pulsing a nitrogen containing precursor until a
desired thickness is formed. Dielectric films containing atomic layer
deposited HfSiON are thermodynamically stable such that the HfSiON will
have minimal reactions with a silicon substrate or other structures
during processing.