Back to results
US 5,291,436 AGranted
Ferroelectric memory with multiple-value storage states
AssigneeRohm Co., Ltd.
InventorAkira Kamisawa
Life of this patent
Estimating the term…
Abstract
A ferroelectric memory using ferroelectric capacitors, in which a plurality of electrodes are juxtaposed on each of the two sides of one ferroelectric substance, and the electric fields between the electrodes are controlled, so that more than two different amounts of charges are provided by the ferroelectric capacitors formed by the electrodes. Thereby, the quantity of storage per ferroelectric cell is increased without increase of the cell area.
Claims3
A ferroelectric memory comprising:
- one electrode relatively large in area provided on a first side of a body of ferroelectric substance;
- two electrodes relatively small in area provided on a second side of the same body of ferroelectric substance;
- a first circuit for selecting one of said electrodes on said second side of said ferroelectric substance in combination with said electrode on said first side of said ferroelectric substance;
- and
- a second circuit for applying a pulse electric field across said electrodes thus selected and said electrode on said first side of said ferroelectric substance;
- whereby three values of polarization inversion states are provided by selectively combining said electrodes on said second side of said ferroelectric substance with said electrode on said first side of said ferroelectric substance.
3 more elements
A ferroelectric memory comprising:
- at least two electrodes provided on a first side of one ferroelectric substance;
- at least two electrodes provided on a second side of said ferroelectric substance;
- and circuit components for applying a pulse electric field between one electrode on said first side of said ferroelectric substance and one of the electrodes on said second side of said ferroelectric substance to provide at least three values of polarization inversion states.
A ferroelectric memory comprising:
- two electrodes provided on a first side of a ferroelectric substance;
- two electrodes provided on a second side of said ferroelectric substance;
- a first circuit for selecting one electrode from said two electrodes on said first side of said ferroelectric substance and one electrode from said two electrodes on said second side of said ferroelectric substance;
- and
- a second circuit for applying a pulse electric field across the two electrodes thus selected,
- wherein four values of polarization inversion states are provided by selection of said electrodes by said first circuit.
3 more elements
Dependencies are inferred from the claim text.