| 摘要 |
PURPOSE:To facilitate and make sure of electrical continuity between wirings even for a highly concentrated refined element without disconnection of wiring by forming at least two layers of metal silicide with a high melting point at a base part of a contact hole, thereby decreasing an effective depth of the contact hole. CONSTITUTION:A contact hole 14 is formed at an oxide film 13 after forming a diffusion layer 12 and the oxide film 13 that is a layer insulation film, too, on a silicon substrate 11. Then a tungsten silicide layer 15 is formed only at a base part of the contact hole 14 with a selective CVD technique, for example. And a polycrystalline silicon layer 16 is formed on the whole plane, for instance, with the CVD technique. The polycrystalline silicon layer 16 is left only at the base part of the contact hole 14 and other parts are removed. When a CVD growth of tungsten silicide is carried out by using a WF6 gas, for example, the polycrystalline silicon layer of the base part of the contact hole 14 is converted into a tungsten silicide layer 19 of an upper layer. In such a case, a ratio of a contact hole area to its depth is improved.
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