DOPED OXIDE FOR SHALLOW TRENCH ISOLATION (STI)

摘要

The embodiments described provide methods and structures for doping oxide in the STIs with carbon to make etch rate in the narrow and wide structures equal and also to make corners of wide STIs strong. Such carbon doping can be performed by ion beam (ion implant) or by plasma doping. The hard mask layer can be used to protect the silicon underneath from doping. By using the doping mechanism, the even surface topography of silicon and STI enables patterning of gate structures and ILD0 gapfill for advanced processing technology.