| 摘要 |
PURPOSE: An apparatus of ferroelectric random access memory(FRAM) and a manufacturing method thereof are provided to reduce the fatigue due to repetitive switching operation, to decrease the operation voltage, and to increase the operation speed. CONSTITUTION: In a ferroelectric random access memory(FRAM), a first transistor(T1) is a ferroelecric NMOS transistor with a ferroelectric insulation surface. Second and third transistors(T2,T3) have each a normal insulation surface. In the write mode, a wordline(W/L) activates from LOW to HIGH, activating the second and third transistors(T2,T3). Thereby a critical voltage above ferroelectric polarization is given between a section line(SL) and a control line(CL). Thus the critical voltage is transmitted to the source nodes(N1,N2) of the second and third transistors(T2,T3). The voltage of the node(N1) is given to the source and substrate of the third transistor(T1). The voltage of the node(N2) is given to the gate of the first transistor(T1). Thus the direction of the polarization of the ferroelectric substrate in the first transistor(T1) is determined by the voltage of the gate and substrate. If the substrate voltage is higher than the gate voltage, logic zero("0") is stored. In the opposite case, logic high("1") is stored.
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