Nonvolatile semiconductor storage device with ferroelectric capacitors
First Claim
1. A nonvolatile semiconductor storage device which stores information using a residual dielectric polarization of a ferroelectric substance and comprises at least one memory cell, whereinsaid memory cell is formed in one element region which is isolated from other regions by an insulating film, said memory cell comprising:
- at least one select transistor;
a plurality of transistors which are connected in series with said select transistor, two neighboring transistors of said plurality of transistors sharing a diffusion region; and
a plurality of ferroelectric capacitors which are arranged correspondingly to said plurality of transistors and each of which has one electrode equivalently connected to a gate electrode of each of said plurality of transistors,the gate electrode of said select transistor is led out as a first word line,a junction between said gate electrode of each of said plurality of transistors and said one electrode of each of said ferroelectric capacitors is led out as a second word line;
another electrode of each of said ferroelectric capacitors is led out as a third word line, anda bit line is connected to one of said diffusion region of said select transistor and the end one of said plurality of transistors.
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Abstract
In an element forming region isolated from other regions by a field oxide, one select transistor and a plurality of MOS transistors are connected in series so that a source/drain diffusion region is commonly owned by two neighboring transistors. The gate electrodes of the MOS transistors are connected to the lower electrodes of ferroelectric capacitors, respectively. The gate electrode of the select transistor, and the lower electrodes and upper electrodes of the ferroelectric capacitors are led out as word lines. A metal wiring which serves as a bit line is connected to a drain diffusion region.
38 Citations
2 Claims
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1. A nonvolatile semiconductor storage device which stores information using a residual dielectric polarization of a ferroelectric substance and comprises at least one memory cell, wherein
said memory cell is formed in one element region which is isolated from other regions by an insulating film, said memory cell comprising: - at least one select transistor;
a plurality of transistors which are connected in series with said select transistor, two neighboring transistors of said plurality of transistors sharing a diffusion region; and
a plurality of ferroelectric capacitors which are arranged correspondingly to said plurality of transistors and each of which has one electrode equivalently connected to a gate electrode of each of said plurality of transistors,the gate electrode of said select transistor is led out as a first word line, a junction between said gate electrode of each of said plurality of transistors and said one electrode of each of said ferroelectric capacitors is led out as a second word line; another electrode of each of said ferroelectric capacitors is led out as a third word line, and a bit line is connected to one of said diffusion region of said select transistor and the end one of said plurality of transistors. - View Dependent Claims (2)
- at least one select transistor;
Specification
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- Resources
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Current AssigneeROHM Co., Ltd.
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Original AssigneeROHM Co., Ltd.
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InventorsNakamura, Takashi, Nakao, Hironobu
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Primary Examiner(s)MINTEL, WILLIAM A
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Application NumberUS07/973,078Time in Patent Office515 DaysField of Search257/300, 257/316, 257/390, 257/391, 257/295, 257/324, 257/314, 365/145US Class Current257/295CPC Class CodesH10B 53/00 Ferroelectric RAM [FeRAM] d...
