Method for removing protuberances at the surface of a semiconductor wafer using a chem-mech polishing technique

摘要

A chemical-mechanical (chem-mech) method for removing SiO2 protuberances at the surface of a silicon chip, such protuberances including "bird's heads". A thin etch stop layer of Si3N4 is deposited onto the wafer surface, which is then chem-mech polished with a SiO2 water based slurry. The Si3N4 acts as a polishing or etch stop barrier layer only on the planar portions of the wafer surface. The portions of the Si3N4 layer located on the top and at the sidewalls of the "bird's heads" and the underlying SiO2 protuberances are removed to provide a substantially planar integrated structure.