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:
Jul. 07, 1992
Filed:
Feb. 20, 1991
Chin S Park, Sunnyvale, CA (US);
Intel Corporation, Santa Clara, CA (US);
Abstract
An improved method for programming a selected memory cell in a virtual ground EPROM array avoids the disturbance of data stored in adjacent memory cells. To avoid disturbance of adjacent cells during programming, the array is efficiently debiased utilizing intercolumn passgates along with slow ramping of the selected column line voltage. The method avoids the disturbance of data stored in adjacent memory cells by first selecting a row line coupled to the selected memory cell and the memory cells adjacent to it. Next, column lines coupled to the source and drain regions of memory cells on one side of the selected memory cell and column lines coupled to the source and drain regions of memory cells on the other side of the selected memory cell are coupled to first and second nodes respectively. The first node is coupled to ground. The potential on the second node is raised at a predetermined rate causing electrons to tunnel onto the floating gate of the selected memory cell, yet in such a manner that the potential across each of the first and second column lines on the other side of the selected memory cell does not disturb the programming state of the adjacent cells.