Integrated self-aligned butt contact process flow and structure for six transistor full complementary metal oxide semiconductor static random access memory cell

摘要

A method of forming a contact between a conductor and a substrate region in a MOSFET device is provided starting with forming a semiconductor substrate with a silicon oxide layer formed on the surface thereof. Then form a stack of a conductor material upon the surface of the silicon oxide layer and form a first dielectric layer upon the conductor material. Pattern the conductor stack into conductors. Form a butted contact pattern in the first dielectric layer by removal of the dielectric layer in at least one butted contact region. Form doped regions in the substrate self-aligned with the conductors. Form an etch stop layer over the device. Form a second dielectric layer over the device and pattern the second dielectric layer with contact openings therethrough down to the substrate and to the butted contact region. Employ the etch stop layer when patterning the second dielectric layer. Remove exposed portions of the etch stop layer subsequent to patterning the second dielectric layer. Form contacts to the substrate and the butted contact regions on the conductor through the contact openings.