Reference circuit having transistor of which threshold voltage controlled by ferroelectric polarization in FeRAM

摘要

PURPOSE: A reference voltage generator having a transistor for controlling a threshold voltage according to a polarizing state of ferroelectric is provided to obtain a stable reference voltage level and easily control the reference voltage level. CONSTITUTION: Each gate electrode of the first and the second transistors(Tr1,Tr2) is operated as lower electrodes of capacitors by laminating ferroelectric layers and upper electrodes on the gate electrodes of the first and the second transistors(Tr1,Tr2) of the first and the second reference cells. The first reference bit line(rb11) and the second reference bit line(rb12) are connected with the first transistor(Tr1) and the second transistor(Tr2), respectively. The first and the second reference bit lines(rb11,rb12) receives equalizing signals and generates reference voltages by the third transistor(Tr3). Each threshold voltage of the first and the second transistors(Tr1,Tr2) is controlled by each polarizing states of the ferroelectric layers.