| 摘要 |
PURPOSE:To enable the manufacture of storage devices corresponding to separate specifications respectively in a short time, by using a construction wherein different pieces of information are written according to the presence or absence of a light-intercepting film. CONSTITUTION:A film having an inferior transmittance of ultraviolet rays, e. g., an SiN film (light-intercepting film) 6, is provided on the surface of an insulating film 5 of EP ROM. Next, according to a separate specification from a user, patterning is applied so that the SiN film 6 is removed in a part (a) wherein writing is to be made as data '1' and that it is left in a part (b) wherein writing is to be made as data '0'. Subsequently, electrons (e) are implanted in floating gates 3 of all parts, '0' is once written therein, and next ultraviolet rays 7 are applied to the entire surface of a device. Then electrons (e) are released from the part (a), while the electrons (e) in the part (b) are left as they are. In this way, the data '1' are written in the part (a) and '0' in the part (b). |
