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. 15, 2008
Filed:
May. 13, 2005
Eungjoon Park, Fremont, CA (US);
Eungjoon Park, Fremont, CA (US);
Abstract
To control the problem of program and erase disturb in flash memory arrays having multiple sectors of cells grouped in each isolation wells of the flash memory array, a refresh procedure is used that involves two readings of each of the cells in a 'refresh area' of a group under different read timing conditions, with other read conditions being constant or varied as desired. Cells that yield the same result in both reads are not excessively disturbed and need not be reprogrammed. However, cells that read differently may be excessively disturbed and should be reprogrammed. The refresh procedure is particularly suitable for memory arrays with small sector size and many sectors per group. The memory arrays preferably incorporate memory cells that use hot electron programming and Fowler-Nordheim erase.