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. 09, 2001
Filed:
Dec. 19, 1997
Prateep Tuntasood, San Jose, CA (US);
Nexflash Technologies, Inc., Santa Clara, CA (US);
Abstract
A method for fabricating a tunnel window in an EEPROM cell that reduces or eliminates the initial active region overlap yet still compensates for tunnel window misalignment. The inventive method accomplishes this by removing a portion of the field oxide layer surrounding an initial active region before depositing the BN+ diffusion layer. This step is performed in order to enlarge the area in which the BN+ diffusion layer is formed to beyond the perimeter of the tunnel window forming a final active region. As a result, the method of the present invention ensures that the tunnel window is fully enclosed by the BN+ diffusion layer despite any tunnel window misalignment that may occur. Reducing the initial active region creates an EEPROM cell with a reduced cell pitch while increasing its coupling ratio.