The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 25, 1996
Filed:
Sep. 29, 1994
Masayoshi Omura, Saitama-ken, JP;
Yoshihiro Ishibashi, Nagoya, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
A ferroelectric memory device according to the present invention includes memory cells. Each memory cell is constructed such that a lower electrode is formed on a silicon substrate, a ferroelectric capacitor having a hysteresis characteristic with at least two non-linear characteristic portions is formed on the lower electrode, and an upper electrode is formed on the ferroelectric capacitor. The memory cells are arranged in a matrix and are provided with a column switching controller and a row switching controller. These controllers are connected via a switching circuit to a write circuit, a read circuit and a detector. When a voltage lower than a coercive voltage is applied to the memory cells, the data storage states of the memory cells are discriminated on the basis of the difference in differential dielectric constants between '1' and '0', thus reading out the data in a non-destructive manner. In the ferroelectric memory device with this structure, an asymmetrical amplitude waveform voltage of a positive voltage lower than a coercive voltage and a negative voltage of an amplitude smaller than the amplitude of the positive voltage is applied to the ferroelectric film on which data is recorded, thereby reading out the data in a non-destructive manner.