Enhanced etch stop capability during patterning of silicon nitride including layer stacks by providing a chemically formed oxide layer during semiconductor processing

A method, comprising:

• forming an etch stop layer on a silicon-containing material layer by performing a wet chemical oxidation process;
• forming a dielectric cap material above said etch stop layer;
• forming a gate electrode structure by patterning said silicon-containing material layer, said etch stop layer and said dielectric cap material;
• exposing said gate electrode structure to at least one reactive process ambient while using said dielectric cap material as a protective material;
• and
• removing said dielectric cap material after exposure to said at least one reactive process ambient selectively to said etch stop layer on the basis of a wet chemical etch ambient.

A method, comprising:

• forming a silicon-containing electrode material on a gate dielectric layer formed on a semiconductor region;
• performing a wet chemical oxidation process so as to form an oxide layer on said silicon-containing electrode material;
• forming a cap material above said oxide layer, said cap material comprising silicon and nitrogen;
• patterning said silicon-containing electrode material, said oxide layer and said cap material on the basis of an etch mask formed above said cap material so as to form a gate electrode structure;
• performing a wet chemical treatment on said gate electrode structure;
• performing one or more processes while using said cap material as a mask;
• and
• removing said cap material on the basis of a wet chemical etch process by using said oxide layer as an etch stop layer.