| 摘要 |
PROBLEM TO BE SOLVED: To provide a non-volatile storage device in which a ferroelectric capacitance is connected to a gate electrode of a field effect transistor(FET) of a metal-insulator-semiconductor(MIS) structure (MISFET) and which can improve its noise immunity in a read mode of the device. SOLUTION: The semiconductor device comprises a ferroelectric capacitance of a ferroelectric (lead zirconate titanate(PZT)) 8 disposed between two electrodes 7 and 9, and a field effect transistor. The field effect transistor is connected at its gate electrode 4 to one 7 of the electrodes of the ferroelectric capacitance. An area of the electrode 9 of the ferroelectric capacitance is set to be smaller than an area (zone B) of a gate pattern of the field effect transistor or than a gate area (zone A) on an active zone of the transistor, so that the ferroelectric capacitance can have a large capacitive value and thus a voltage applied to the ferroelectric 8 can become large. Thereby an electric field applied to the ferroelectric 8 is also large with its increased polarization. Since the voltage applied to a gate insulating film 3 is decreased, the gate insulating film can be set to have a sufficiently high breakdown voltage, its application voltage can be increased, and further its polarization can be made large. |
