Poly gate CD passivation for metrology control

摘要

Various methods of fabricating gate structures, such as gates and gate stacks are provided. In one aspect, a method of fabricating a gate electrode on a substrate is provided that includes depositing a polycrystalline silicon film on the substrate and etching the polycrystalline film into a desired shape with a first sidewall and a second and opposite sidewall. A passivating oxide film is formed with a preselected thickness on the first and second sidewalls by oxidizing the silicon structure with a heated aqueous solution of ammonium hydroxide and hydrogen peroxide. Gate electrode formation with an oxide coating film of known thickness is provided. Linewidth metrology accuracy may be improved.