MIS device prodn. with protective film formation on exposed metal - before doping by heat treatment of prevent oxidn. and evapn. of metal, pref. molybdenum

摘要

Prodn. of a semiconductor device involves (a) forming an insulating film (of Si oxide) on a semiconductor substrate surface; (b) forming double conducting film, consisting of a semiconducting (polycrystalline Si) film and a metal (Mo, W, Tri or Cr) film, on selected regions of this; (c) providing a protective film (of phosphosilicate glass or polycrystalline Si) on the exposed metal surface; and (d) introducing a dopant of a specific conductivity type into the substrate from the surface of the points not covered by the double conducting film, using heat treatment. Rapid oxidn., e.g. of Mo, and evapn. from the gate electrode during heat treatment for the formation of the source and drain zones is avoided. MIS devices with stable properties and high packing density are obtd.