| 摘要 |
PURPOSE:To reduce manufacturing period from the time of obtaining ROM data to that of delivery of products, by performing the ion implantation for data writing by using a metal film as a mask, and performing data writing after a final protective film is formed at the time of manufacturing the ROM. CONSTITUTION:As an insulating resin film, a photoresist film 10 is spread on the whole surface, and baking is performed. Thereon a metal film 11 for a mask is formed, on which a photoresist film 12 is spread, and baking is performed. By photolithgraphy, the resist film 12 is patterned so as to have an aperture in the channel region of a MOS transistor. By using the resist film 12 as a mask, the metal film 11 is etched. By using the metal film 11 as a mask, ion implantation is performed with acceleration energy to penetrate the resist film 10, a final protective film 9, an interlayer insulating layer 7, a gate electrode 6 and a gate oxide film 5. The resist film 10, the metal film 11 and the resist 12 are eliminated. The implanted impurity is activated. Thereby the manufacturing process is shortened. |
