STI recess method to embed NVM memory in HKMG replacement gate technology

摘要

The present disclosure relates to a structure and method for reducing contact over-etching and high contact resistance (Rc) on an embedded flash memory HKMG integrated circuit. In one embodiment, an STI region underlying a memory contact pad region is recessed to make the STI surface substantially co-planar with the rest of the semiconductor substrate. The recess allows formation of thicker memory contact pad structures. The thicker polysilicon on these contact pad structures prevents contact over-etching and thus reduces the Rc of contacts formed thereon.