Patent ID: 6646905
Filing Date: 2003-11-11
Classification: G11C

Abstract:
A ferroelectric storage device having 2Tr-2C cell structure, comprising:memory cells each including: a first ferroelectric capacitor connected in series with a first selection transistor which is selected by a word line; and a second ferroelectric capacitor connected in series with a second selection transistor which is selected by said word line, said first and second ferroelectric capacitors having opposite polarization; a first bit line connected to one end of said series connection of said first ferroelectric capacitor and said first selection transistor and having a bit line capacitor; a second bit line connected to one end of said series connection of said second ferroelectric capacitor and said second selection transistor, and having a bit line capacitor; a plate line connected to the other end of said series connection of said first ferroelectric capacitor and said first selection transistor and to the other end of said series connection of said second ferroelectric capacitor and said second selection transistor, said plate line adapted to provide a predetermined voltage; a voltage detection means connected between said first bit line and second bit line; one external reference voltage input terminal for receiving an external reference voltage; first control switch means connected between said external reference voltage input terminal and said first bit line, and switchable between ON and OFF by a first test signal; and second control switch means connected between said external reference voltage input terminal and said second bit line, and switchable between ON and OFF by a second test signal, wherein only one of said first and second control switch means is selectively turned ON by said first or second test signal.