| 摘要 |
PURPOSE:To prevent the corrosion of a wiring metal layer by the elution of phosphorus by a method wherein a layer insulating film including high-concentration phosphorus is surrounded by a silicon nitride film. CONSTITUTION:A silicon nitride film 14 is formed by precipitation with a thickness of about 500-1,000Angstrom on the whole surface of a silicon substrate 1 formed a MOSFET and a PSG film 15 including phosphorus of about 8-12% by weight is formed with a thickness of about 1mu on the whole surface of the film 14. Next, the PSG film 15 is etched by using a photoresist as a mask and a contact hole 16 is formed at the part of the MOSFET and resistor or the like. Next, after doing softening drift to the PSG film 15 by thermal treatment, a silicon nitride film 17 is formed on the whole surface of the PSG film 15. The silicon nitride films 14, 17 are connected to each other at the contact hole section 16 and wiring is done by forming the second contact hole haing a smaller diameter than that of the hole section 16 at the films 14, 17 of the contact hole section 16. |
