Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To prevent the formation of an eave section by a method wherein an upper layer film is etched, a resist is softened, an opening circumferential edge is coated, and lower layer films are etched when the films having different quality are coated with the same resist mask and etched. CONSTITUTION:An SiO2 thin-film 22 and poly Si 23 are piled up on an Si substrate 21, and oxidized in wet types and an SiO2 thick film 24 is made up. The thick film 24 is coated with a resist mask 25, and etched with an HF solution, the whole is heated at about 170 deg.C, the resist is stoftened, and a side surface of the film 24 and the boundary sections of the film 23 are coated. When the poly Si 23 is etched with a gas, the principal ingredient thereof is CF4, and the SiO2 22 is etched with HF, an eave section is not formed. When the resist 25 is removed, SiO2 27 is also built up to a side surface and a conductive layer of poly Si 28 is formed by means of a CVD method, there is necessity for excessive etching when patterning the conductive layer because there exists no eave section.

Inventors

• 👤 Kazuaki Yamanochi

Bibliographic Details