| 摘要 |
PURPOSE:To prevent the diffusion of boron and to prevent precipitation of silicon at a contact part between a wiring and a substrate, by forming a PSG film between a BPSG film and the wiring. CONSTITUTION:A PSG film 5 is formed on a silicon substrate 1, and a BPSG film 2 is formed on the film 5. Then, the PSG film 5 and the BPSG film 2 are simultaneously removed selectively by using photoresist, and a contact hole 4 is formed. A PSG film 5a is formed at an approximately unifor thickness on the surface. Of the PSG film 5a, only the parts on the side surfaces of the BPSG film 2 and the PSG film 5 are made to remain, and the other part is removed by anisotropic etching. The contact hole 4 is buried, and an aluminum silicon alloy film is formed. The alloy film is selectively removed by using photoresist, and a wiring 3 comprising the aluminum silicon alloy is formed.
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