Semiconductor memory device having multiple memory arrays and including redundancy circuit for repairing a faulty bit

摘要

Column repairing circuits 7a, 7b for repairing a DRAM in which there are defective memory cells in two columns are disclosed. The connection state of switching elements or circuits 51-5n, 61-6n, 71-7 (n+ 1), 81-8 (n+ 1) is determined as illustrated by appropriately disconnecting fuses in fuse links provided respectively in circuits 7a, 7b. Accordingly, column selecting lines Y2a and Y (n+1) b in memory array blocks 891a, 891b are not activated. The two repairing circuits 7a, 7b are provided spaced apart from each other on a semiconductor substrate, so that excessive concentration of fuse elements and switching elements or circuits is prevented.