Nitrogen-rich barrier layer and structures formed

The present invention discloses a method for forming a layer of nitrogen and silicon containing material on a substrate by first providing a heated substrate and then flowing a gas which has silicon and nitrogen atoms but no carbon atoms in the same molecule over said heated substrate at a pressure of not higher than 500 Torr, such that a layer of nitrogen and silicon containing material is formed on the surface. The present invention is further directed to a composite structure that includes a substrate and a layer of material containing nitrogen and silicon but not carbon overlying the substrate for stopping chemical species from reaching the substrate. The present invention is further directed to a structure that includes a semiconducting substrate, a gate insulator on the substrate, a nitrogen-rich layer on top of the gate insulator, and a gate electrode on the nitrogen-rich layer, wherein the nitrogen-rich layer blocks diffusion of contaminating species from the gate electrode to the gate insulator.