Metal contact to a novel polysilicon contact extension

摘要

A method has been developed for forming a metal contact structure, to an underlying polysilicon contact extension structure, without degrading the polysilicon contact extension structure during the metal contact structure patterning procedure. The process features opening a hole in an insulator layer, to an underlying polysilicon extension structure. The overlying metal contact structure is then patterned to have a width larger then the width of the opened hole in the insulator. Therefore the underlying polysilicon contact extension structure is not exposed to the RIE procedures used to define the metal contact structure.