A 256K dynamic RAM with page-nibble mode

A 5-V 256K /spl times/ 1 bit NMOS dynamic RAM with page-nibble mode is designed and fabricated using 2-/spl mu/m design rules and folded bit-line configuration. Molybdenum disilicided polysilicon is used as the second-level gate to reduce the word-line signal delay. A large 98 /spl mu/m/SUP 2/ cell with Hi-C structure stores the signal charge of 210 fC and provides this memory with wide operating margin. The device is immune to voltage bumping and uses laser programmable redundancy. Typical RAS/CAS access times are 80 ns/40 ns. An average operating current of 50 mA with 80 mA peak at 230 ns cycle time and standby current of 2 mA are achieved.