| 摘要 |
PURPOSE:To prevent malfunction due to impurity implantation into a semiconductor substrate by arranging BBG's on a chip so as to be dispersed into a plurality of units. CONSTITUTION:On a silicon substrate chip on which an integrated circuit device is formed, a plurality of board bias generating circuits (BBG) 6-9 are separately arranged. As to the BBG'S 6-9, impurity is implanted in the substrate via wiring 10, 11, usually according to the amount defined by circuit design. However, in the case where the threshold voltages of transistors Q1, Q11 are high, node points B1, B2 and the substrate are forward-biased, and electron being impurity is implanted, so that a failure mode, wherein data are destructed, is exhibited. Then the node points, which are apt to be forward-biased, are divided in order to avoid the concentration of impurity implantation. Further, by arranging the node points at positions considerably distant from a memory cell array 5, data destruction of memory cell can be prevented, thereby preventing the malfunction caused by impurity implantation into the substrate. |
