MANUFACTURE OF SEMICONDUCTOR DEVICE

PURPOSE:To enable an MIS-type capacitor of large capacity and high precision to be formed with superior yield inside an IC chip, by correcting film thickness of an Si3N4 film by etching and oxidation and then covering the surface with a polycrystal silicon layer for its protection and processing other element parts of the IC. CONSTITUTION:In case of manufacturing a semiconductor device containing an MIS-type capacitor with a silicon nitride film serving as dielectric, a process of element isolation is finished and then an opening part for the MIS-type capacitor is formed at a field oxide film 17 covering the surface of semiconductor substrate, to expose the second conduction type semiconductor electrode layer 15. This exposed surface is covered with a silicon nitride film 18 and the silicon nitride film 18 is etched and oxidized to correct its film thickness into definite one. The corrected silicon nitride film 18 is covered with a polycrystal silicon layer 19 for its protection, to form other elements in a protective state by this polycrystal silicon layer 19. Besides, a metallic electrode layer 15 of the MIS-type capacitor is piled on the polycrystal silicon layer 19. NH4F or the like is used to etch the said silicon nitride film for film-thickness correction.