| 摘要 |
PURPOSE:To make it possible to utilize the circuit even though it has defects without discarding it, by preparing a plurality of circuit blocks with the same function comprising high density active element regions which tend to include serious defects, wiring the selected good circuit so as to contribute the operation, thereby improving the circuit design and the yield rate. CONSTITUTION:In a microcomputer chip in an example in the figure, two ROMs and two ALUs having the same functions, respectively, are prepared. In this constitution, e.g. in the ROMs (A) and (B), the probability of the even either of (A) or (B) does not have the defect is twice the probability of the event the ROM (A) does not have the defect. Then a plurality of the blocks (e.g. two), which are formed by the high density active elements and have a small occupying area, and whose probability of the event of including the defect is low, are intentionally prepared. A selecting circuit (e.g. a fuse circuit wherein polysilicon is used) is provided for each block. The characteristics of the blocks are checked by the selecting circuits, and the block which does not have the defect is selected. Then the yield rate is improved by twice or more by only increasing a pellet area by 1.5 times. |
