High tolerance operation of 1T/2C FeRAMs for the variation of cell capacitors characteristics

Abstract

The operation of an FeRAM test chip is demonstrated with an 8 kbit cell array, sense amplifiers and other peripheral circuits for confirming the high tolerance of the 1T/2C FeRAM. The test chip is successfully fabricated by using a double layer metal process. The voltage difference to be amplified in data read for the 1T/2C FeRAM is 86 mV, which is large enough to operate, and four times larger than that for conventional 1T/1C FeRAM, after the cell capacitors characteristics are degraded and varied.