| 摘要 |
PURPOSE:To contrive improvement in reliability of the title semiconductor device by a method wherein, after a lower wiring has been formed by etching using a mask, the mask is removed, an isotropic etching is performed on the wiring until the desired film thickness is obtained, and the inclination of the end part of the wiring is made small, thereby preventing the short circuit generating from the etching residue on the upper layer wiring. CONSTITUTION:The lower layer wiring film 3 of polycrystalline silicon is grown on the insulating film 2 of a substrate 1 in the thickness which is a little thicker than normally required. Then, the mask 4 of the photoresist formed into the desired wiring pattern is formed on said wiring film 3, and a lower layer wiring 3a is formed. Subsequently, when a plasma isotropic etching is performed until the wiring 3a has a needed thickness under the condition wherein the mask 4 is removed and the wiring 3b is exposed, the end part of the wiring 3a is rounded off, and a wiring 3b having a gentle inclination is formed. Then, an interlayer insulating film 5 is formed by oxidizing the surface of the wiring 3b, and after an upper layer wiring film 6 of tungsten and the like has been coated thereon, a photoresist mask 7 is formed in the required pattern form. Then, an upper layer wiring 6a is formed by performing an anisotropic etching on the upper layer wiring film 6.
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