How low-energy ions can enhance depositions on low-K dielectrics

Ultrathin titanium nitride layers grown on three different dielectrics were studied to examine how low-energy ions change the chemical composition at and near their interface. Comparisons were made by growing titanium nitride under similar conditions both with (ion-assisted) and without (reactive) n itrogen ions. Although the chemical reactions between the titanium nitride and the three dielectrics under both growth conditions depend on the type o f dielectric used, a few general observations were seen. In comparison with the reactively grown samples, all of the ion-assisted growths show a signi ficant increase in the amount of nitride in the titanium nitride layer at a nd near the titanium nitride/dielectric interface. Moreover, the amount of chemical binding between the titanium nitride and dielectric is increased w hen low-energy ions are used. Finally, by using angle resolved x-ray photoe mission it was determined that the enhancement in the deposition process fr om low-energy ions occurs without inducing significant intermixing between the titanium nitride layer and the dielectric. (C) 2000 American Vacuum Soc iety. [S0734-2101(00)00105-6].