| 摘要 |
PURPOSE:To prevent wire breakdown in interconnections, by providing the concentration distribution of an added composition, which is increased from a lower layer toward an upper layer on an interlayer insulating film, thereby sufficiently depositing the material of an upper interconnection layer even in a contact hole. CONSTITUTION:An Al-Si interconnection 3 is formed on a field oxide film 2 as the first interconnection on a silicon substrate 1. A phosphorus glass film 4, in which phosphorus concentration is continuously changed, is deposited. As a result, the phosphorus concentration is continuously changed from 0 to 3.5 mol % from the lower layer toward the upper layer in the glass film 4, and the glass film 4 is grown to a constant thickness. Thereafter, a contact hole part 5 in the glass film is etched by using a dry etching method. Since the phosphorus concentration of the phosphorus glass film 4 is continuously changed from the lower layer to the upper layer in the range of 0-3.5 mol %, the side etching amount becomes larger toward the upper layer. The side wall of the contact hole is formed so that it has the slant surface with respect to the surface of the substrate 1. Therefore, when an Al interconnection 6 is deposited as the second interconnection, it is sufficiently deposited in the hole since the side wall of the contact hole is the slant surface.
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