| 摘要 |
PURPOSE:To prevent a gate electrode or a diffusion region from being damaged due to excessive etching treatment when an aperture for information writing is formed by causing a layer insulation film of a MOS element to be a double layer insulation film having dlfferent etching speeds. CONSTITUTION:A gate oxide film 3, a field oxide film 2, a gate electrode 4, and diffusion regions 5 are formed on a substrate 1. And the first insulation film 6 that is composed of a material having a low etching speed and the second insulation film 7 that is composed of a material having an ordinary etching speed are formed on the whole surface of the substrate. And then, a contact hole 9 and an interconnection part 8 are formed. Subsequently, resist patterns 10 adhere to the insulation film so as to form an ion-implantation aperture for information writing and a desired part of the above second insulation film 7 is removed by etching treatment. In the event of etching, the first insulation film 6 is not treated by etching but functions as an inhibitor for etching and as a result, the above film 6 keeps the gate electrode 4 and diffusion regions 5 that are coated this film 6 from being damaged due to excessive etching treatment. |
