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:
May. 21, 2002
Filed:
Nov. 27, 2000
Sang Hoan Chang, Kyungki-Do, KR;
Ki Seog Kim, Kyungki-Do, KR;
Jin Shin, Seoul, KR;
Keun Woo Lee, Kyungki-Do, KR;
Hyundai Electronics Industries Co., Ltd., Kyungki-Do, KR;
Abstract
There is disclosed a method of monitoring a source contact in a flash memory by which whether a source contact having a narrow contact area contacts or not can be easily monitored using over-erase cell characteristic in a flash cell, in a flash memory device in which a source line is formed by a local interconnection method. In the present invention, in order to monitor a contact state at source contacts, the same voltage to the erase condition of a cell is applied to respective terminals (VG terminal, VD terminal, VS terminal and VSS terminal) wherein all the electrons existing at a floating gate in all the cells connected to the VS terminal and VSS terminal become turned on so that they can be over-erased. On the other hands, as electrons existing at the floating gate in two cells shared by any source contacts having a defect contact are not erased, the cells remain turn-off. In this state, if test voltages (VG=0V, VD<5V, VS=float, VSS= ground) are applied, the current flow from the VD terminal to the VSS terminal is broken in the portion having a contact defect, thus allowing the contact state of the source contacts to be monitored.