Method for improving control gate uniformity during manufacture of processors with embedded flash memory

摘要

A method is provided for the manufacture of an integrated semiconductor device that includes an embedded flash memory array formed in a recessed region of a semiconductor substrate, the method includes, prior to formation of floating and control gate stacks of the memory array, depositing a protective layer over layers of gate material, and depositing a self-leveling sacrificial layer over the protective layer to produce a substantially planar upper surface. The sacrificial layer is then etched to a depth that removes the sacrificial layer and leaves a substantially planar face on the protective layer. A photo mask is then deposited on the protective layer and the gate stacks are etched from the layers of gate material.