| 摘要 |
PURPOSE:To obtain the structure of storage cell transistors which are superior in numeral efficiency per column line by providing one more storage cell transistor that is connected to the same row line between three pieces of respective adjacent column lines in addition to two pieces of storage cell transistors that are ordinarily provided by having the same row lines. CONSTITUTION:In a read-only storage device consisting of storage cell transistors 13 that are disposed at the main surface of a semiconductor substrate and a plurality of row lines 11 and column lines 12 and 12a that are connected to the storage cell transistors 13, the storage cell transistors 13 having the same row lines 11 among three pieces of respective adjacent column lines 12 and 12a are disposed. For example, the row lines 11 are held in common; besides, to the storage cells 1311 and 1312 that are connected to the columns 12 and 12a and are disposed in the form of matrix, a storage cell 131a is provided in the vicinity of the storage cells in such a way that the row lines 11 are held in common and, being connected to the column line 12 that is formed on every other column line, its storage cell 131a is thus added. Then three pieces of the storage cells 1311, 1312, and 131a are disposed in a region in which the column lines 12, 12a, and 12 as well as the neighboring row lines 11 are formed so that they are composed as a group unit. |
