Method for manufacturing a semiconductor device using a nitrogen containing oxide layer

A method for manufacturing a semiconductor device, comprising:

• forming a silicon oxynitride dielectric layer by growing or depositing a silicon dioxide layer over a substrate and subjecting the silicon dioxide layer to nitridation using a nitrogen containing plasma to introduce nitrogen atoms into the silicon dioxide layer;
• forming a polysilicon layer over the silicon oxynitride layer;
• patterning the polysilicon and silicon oxynitride layers to form a gate structure including a polysilicon gate electrode over a silicon oxynitride dielectric;
• the silicon oxynitride gate electrode having a substantially same nitrogen concentration at edges as at a center;
• prior to oxidation of the polysilicon gate electrode, subjecting the gate structure to further nitridation using a nitrogen containing plasma to incorporate additional nitrogen atoms into edges of the silicon oxynitride gate dielectric, wherein the nitride region is located along all of the sidewalls of the gate dielectric and also along all of the sidewalls of the polysilicon gate electrode and along the top surface of the substrate;
• after subjecting the gate structure to the further nitridation, subjecting the gate structure to an oxidant comprising N2O or NO for oxidation of the polysilicon gate electrode to generate a nitrogen containing oxide layer along all of the sidewalls of the nitride gate dielectric and along the top surface of the substrate;
• after oxidation of the polysilicon gate electrode, forming sidewalls on the gate structure;
• and
• forming source/drain implants in the substrate adjacent the sidewalls,
• the nitridation serving to compensate for loss of nitrogen atoms at the edges of the silicon oxynitride gate dielectric during oxidation.

A method for manufacturing a semiconductor device, comprising:

• forming a gate structure over a substrate, the gate structure including a nitrided gate dielectric located over the substrate and a gate electrode located over the nitrided gate dielectric electrode and along the top surface of the substrate;
• prior to an oxidation of the gate electrode, forming a nitride region using a nitrogen containing plasma conformally entirely along sidewalls of the nitrided gate dielectric, entirely along sidewalls of the gate electrode, and along an exposed upper surface of the substrate and also along all of the sidewalls of the gate electrode and along the top surface of the substrate;
• after subjecting the gate structure to nitration, forming a nitrogen containing oxygen layer conformally over the nitride region entirely along the sidewalls of the nitrided gate dielectric, entirely along the sidewalls of the gate electrode, and along the upper surface of the substrate with the nitride region separating the nitrogen containing oxide layer from the exposed upper surface of the substrate, wherein the oxidation of the gate electrode includes the forming the nitrogen containing oxygen layer,
• wherein the nitrided gate dielectric is formed by forming a silicon dioxide gate dielectric layer over the substrate, and thereafter subjecting the silicon dioxide gate dielectric layer to a nitrogen containing plasma source to introduce nitrogen into the silicon dioxide gate dielectric layer,
• the forming of the nitride region serving to compensate for loss of nitrogen atoms at the edges of the nitrided gate dielectric during oxidation.