Patents Assigned to SGS-Thomson Microelectrics s.r.l.
  • Patent number: 4966867
    Abstract: A process for forming self-aligned metal-semiconductor contacts in integrated MISFET devices determining during a phase of the fabrication the presence on the surface of a wafer of parallel gate lines of polycrystalline silicon provided with lateral "spacers", is founded on the formation of a dielectric oxide layer of a differentiated thickness, having a reduced thickness on the bottom of the valley between two adjacent gate lines wherein the contacts must be formed. The method comprises conformably depositing a first layer of dielectric silicon oxide, a second layer of precursor polycrystalline silicon and a third layer of nitride, followed by depositing a layer of planarization SOG. By blanket etching the SOG layer and the nitride layer, the crests of the precursor polycrystalline silicon layer are exposed. A residual layer of nitride is left inside the valley between adjacent gate lines.
    Type: Grant
    Filed: October 20, 1989
    Date of Patent: October 30, 1990
    Assignee: SGS-Thomson Microelectrics s.r.l.
    Inventors: Pier L. Crotti, Nadia Iazzi