| 摘要 |
PURPOSE:To reduce the occupied area of a protecting element, and prevent leak current from increasing even at the time of high temperature, by forming, on a polycrystalline silicon layer, an aluminum wiring with a specific width via an insulating film, and using an air gap formed in a window part of the insulating film, as a protecting element for electrostatic breakdown. CONSTITUTION:The square of W being the wiring width of an aluminum wiring 8 on a boron and phosphorus doped glass layer(BPSG) film 6 is made more than or equal to 300times the area of a window 9 formed on the BPSG layer 6. As a result, by heat treatment to make an ohmic contact of the aluminum wiring, polycrystalline silicon is abnormally diffused in the aluminum wiring layer. Therefore, in the window 9 formed in the BPSG layer 6, the polycrystalline silicon vanishes as the result of reaction with aluminum, and an air gap 7 is formed between the aluminum wiring 8 and a polycrystalline silicon layer 5. The air gap is used as a protecting element for electrostatic breakdown, thereby reducing the occupied area of the protecting element, and preventing the increase of leak current even at the time of high temperature. |
