| 摘要 |
A highly reliable method for forming contact plugs is provided. The method can prevent short circuiting from occurring between self aligned contact plugs and word lines or between self aligned contact plugs and bit lines by applying a material, whose etching speed ratio relative to that of the silicon-based insulating film is 100 or more, to an interlayer film for forming the contact plugs therein. The method comprises forming wiring lines each of which is covered with silicon oxide films at its top surface and lateral sides, forming a sacrificial interlayer film overall, which is made up of an organic coating film without containing silicon, so as to cover the wiring lines, forming contact holes by sequentially etching the sacrificial interlayer film and a lower-layer insulating film, and forming contact plugs. The method further comprises forming columns of the contact plugs by removing the sacrificial interlayer film, forming an interlayer insulating film overall, and partially removing the interlayer insulating film from above the surface thereof to expose the surfaces of the capacitor contact plugs.
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