SEMICONDUCTOR MEMORY

© A folded bit line DRAM (10), with even and odd rows of memory cells (MC), includes spare even (SR2) and odd (SR1) rows of memory cells which can be substituted for standard rows found to have defective cells or interconnections. Each decoder (1, 2) associated with a standard row can be disconnected if associated with a defective row. A spare decoder (3) is associated with one spare even (18) and one spare odd (18) row of memory cells and is normally deselected for any address, but is able to assume the address of any disconnected standard row. Disconnection of a standard decoder and substitution of a spare decoder with the appropriate even or odd row are effected by selectively opening fusible links (F1-F9) by laser irradiation. The use of one spare decoder with both an even and odd row reduces the number of spare decoders and thus reduces overall chip size.