A method of storing and accessing two data bits in a single ferroelectric
FET includes selectively polarizing two distinct ferroelectric regions in
the same gate dielectric layer separated by a non-ferroelectric dielectric
region. A first ferroelectric region is sandwiched between the substrate
and the gate terminal in the region of the source and is polarized in one
of two states to form a first data bit within the FET. A second
ferroelectric region is sandwiched between the substrate and the gate
terminal in the region of the drain and is polarized in one of two states
to form a second data bit within the FET. Detection of the first data bit
is accomplished by selectively applying a read bias to the FET terminals,
a first current resulting when a first state is stored and a second
current resulting when a second state is stored. The polarization of the
second data bit is accomplished by reversing the source and drain
voltages.
