| 摘要 |
A lower wiring layer is formed on an insulating film 12 covering a semiconductor substrate 10. The wiring layer 14 has a laminated structure of a barrier metal layer such as WSi2, an Al or Al alloy layer, and a cap metal layer such as WSi2 formed in this order from the bottom. The cap metal layer is caused to contain conductive material such as Al by using an ion injection method or the like. After forming an insulating film covering the wiring layer, a contact hole is formed in the insulating film by a dry etching process using a resist layer as a mask. The dry etching process uses a fluorine based gas such as CHF3 as the etching gas. With this etching gas, fluoride such as Al fluoride (AlF3) is generated to suppress the etching of the cap metal layer.
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