Study of PECVD SiOxNy films dielectric properties with different nitrogen concentration utilizing MOS capacitors

We observed a variation of Dit in function of the films nitrogen concentration, the smallest obtained value corresponding to the Si3N4 film (∼1 × 1011 cm−2 eV−1), however this film presents higher leakage current density than others. In order to optimize both parameters a double dielectric layer is proposed, a first layer of Si3N4 film, which presents the highest dielectric constant and best interface properties, and a second layer of SiOxNy with high nitrogen concentration, in order to maintain the equivalent dielectric constant high but minimizing the leakage current problems.