Semiconductor metal contamination reduction for ultra-thin gate dielectrics

摘要

A bilayer dielectric structure for substantially reducing or eliminating metal contaminants formed during subsequent polysilicon deposition is provided. The bilayer dielectric structure includes an upper surface region that is rich in chlorine located atop a bottom surface region. The upper surface region that is rich in chlorine removes metal contaminates that are present atop the structure during subsequent formation of a polysilicon layer. A method of forming the bilayer structure is also provided.