| 摘要 |
PROBLEM TO BE SOLVED: To obtain a highly reliable semiconductor device having a multilayer wiring structure for connecting its upper and lower-layer wiring layers via a plug, by preventing its side-etch from occurring in the interface between its upper-layer wiring layer of a border-less portion and the plug in the case of the etching performed when patterning its upper-layer wiring layer. SOLUTION: By the burying of a connection hole 14 provided in an interlayer insulation film 13, a metallic film for a plug is formed. Then, after covering with a resist mask having its size somewhat larger than the size of the connection hole 14 the region to form therein the connection hole 14, the metallic film for a plug is so etched to its predetermined thickness by an anisotropic etching as to obtain the metallic film having a partially protruded portion thereon and extinguish naturally the resist mask. Thereafter, by the expansive etchback of the metallic film, a plug 15 protruded in the form of a dome from the surface of the interlayer insulation film 13 is formed. As a result, the film thickness of an upper-layer wiring layer 17 is made small above the region to form the plug 15.
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