| 摘要 |
PURPOSE:To prevent disconnection of metallic wiring, by providing a double- layer structure of an SiO2 film and a BPSG film for insulating films, forming a contact hole only at the part of BPSG film, performing heat treatment at a high temperature, etching the remaining SiO2 film, and completing the contact hole. CONSTITUTION:Insulating films are formed on a semiconductor substrate 101, on which a diffused layer 102 is formed, with two layers of a silicon dioxide film (SiO2 film) 103 and a borophos phorosilicate glass film (BPSG film) 104. Only the BPSF film 104 at a part, where a contact hole is to be formed, is etched at first. Thereafter, high temperature heat treatment is performed, and the BPSG film 104 undergoes reflowing. An arbitrary taper angle is imparted to the edge of the BPSG film 104 after etching. The SiO2 film 103 at the lower layer is further etched, and the contact hole is formed. Thus the contact hole, which has the sufficient taper angle that prevents the disconnection a metallic wiring at the contact hole part, can be formed without adverse effect on the characteristics of elements.
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