US Patent 7655532 STI film property using SOD post-treatment

A method of forming a shallow trench isolation region includes providing a semiconductor substrate comprising a top surface; forming an opening extending from the top surface into the semiconductor substrate; filling a precursor into the opening using spin-on; performing a steam cure to the precursor to generate a dielectric material; after the steam cure, performing a chemical mechanical polish (CMP) to the dielectric material; and after the CMP, performing a steam anneal to the dielectric material.