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:
Jan. 25, 2005
Filed:
Nov. 20, 2003
Masaki Aoki, Kawasaki, JP;
Masaki Aoki, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
Prior to the first read operation for reading data from real memory cells, the second read operation for reading data from dummy memory cells is carried out using reference memory cells. A reduced residual dielectric polarization values of ferroelectric capacitors of the reference memory cells due to heat treatment and the like in manufacturing process, is recovered by the second read operation to an original value before the read access to the real memory cells. Therefore, data in the real memory cells is properly read out in the subsequent first read operation. As a result, it is possible to certainly read data from a ROM area in a ferroelectric memory to which data is written in advance in a test process of the manufacturing process, for example.