| 摘要 |
PURPOSE:To prevent decrease in insulating withstanding voltage, by wrapping a high-melting-point metal or a lower interconnection layer of its silicide with an insulating film layer having an SiN film or a film layer, through which heavy metal is hard to penetrate, such as Si. CONSTITUTION:On a poly Si film 3, high-melting-point metal or a lower interconnection layer 4 of its silicide is formed. The Si film 3 and the lower interconnection layer 4 are patterned. On the surface of the lower interconnection layer 4, a diffusion stopping film 5 comprising poly Si is applied and formed. An SiO2 film 6 is deposited or a composite film of the diffusion stopping film 5 comprising the SiN film and the SiO2 film 6 is formed. Thereafter, an upper interconnection layer 7 is formed. Thus the high-melting-point metal or the lower interconnection layer 4 of its silicide is surrounded by the insulating film layer, in which the SiN film or the poly Si film layer is the diffusion stopping layer 5. Since the heavy metal impurities are not diffused in this layer, the withstanding voltage of the insulating film layer is maintained.
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