| 摘要 |
PURPOSE:To accurately form an ultrafine pattern by forming a reverse pattern made of an oxidation preventive film on a polycrystalline silicon film or a metal silicide film, oxidizing it at a high temperature, forming the prescribed pattern made of a dioxidized silicon siO2 film on the film and then patterning it with the SiO2 as a mask. CONSTITUTION:With a resist film pattern 5 as a mask an exposed Si3N4 film 4 is removed by dry etching, the film 4 is used as an oxidation preventive film, and the pattern is heat treated in an oxidative atmosphere, thereby forming an SiO2 film 6 on the exposed polycrystalline silicon film. The film 4 and the polycrystalline silicon film 3 utilized as the oxidation preventive films are etched and removed by a dry etching method. Thus, the polycrystalline silicon film exposed with the film 6 as a mask can be removed by etching, and when an ultrafine SiO2 film pattern is formed, a faithful polycrystalline silicon film pattern can be formed. The remaining SiO2 film mask is etched and removed by hydrofluoric acid solution, thereby completing the wiring layer of the polycrystalline silicon film 8. |
