| 摘要 |
PURPOSE: A method for forming an interlayer dielectric is to minimize damage of a ferroelectric capacitor due to a hydrogen gas included in a source gas in a process of forming the interlayer dielectric on the capacitor. CONSTITUTION: On a semiconductor substrate(20), a ferroelectric capacitor is formed composed of a lower electrode(21), a ferroelectric layer(22) and an upper electrode(23). A polysilicon layer(24) is deposited on the entire structure. The polysilicon layer is annealed at 500 to 900 deg.C in an oxygen atmosphere to oxidize it and to simultaneously diffuse the excess oxygen into the ferroelectric layer. The oxidized polysilicon layer acts as a barrier against a reducing gas in a subsequent interlayer dielectric forming process. Further, the ferroelectric layer recovers ferroelectric properties through the diffusion of oxygen. Finally, an interlayer dielectric(25) is formed on the polysilicon layer.
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