JPS5773977A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a multilayer wire without disconnection by employing an SiO2 film, an Si3N4 film, a polycrystalline Si film, etc. when forming an IGFET and freely limiting the thickness of an insulating film on the upper surface. CONSTITUTION:An SiO2 film 2 is covered on an N type Si substrate 1, a substrate surface 3 is exposed corresponding to source, drain and gate forming regions, and a gate SiO2 film 4 integral with the film 2 is covered thereon. Subsequentlu, an Si3N4 film 5, a polycrystalline Si film 6, an Si3N4 film 7 are laminated, are photoetched, and the film 7 and a film 8 made only of the film 7 are retained on the gate forming region and the wire forming region. Thereafter, with them as masks it is etched to retain the film 6, a gate 11 and a wire 10 only under the films 7, 8, are heat treated, and an SiO2 film 12 is formed at the side face. Thereafter, it is etched to remove the exposed films 5, 8, 9, P type impurity is diffused to form P type source and drain regions 14, 16, and the electrode 11 and the wire 10 are imparted with conductivity.