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:
Apr. 01, 1997
Filed:
Jun. 05, 1995
Claude L Bertin, South Burlington, VT (US);
Donelli J DiMaria, Ossining, NY (US);
Makoto Miyakawa, Tokyo, JP;
Yoshinori Sakaue, Tokyo, JP;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A three-dimensional memory cell, suitable for electrically erasable programmable read only memories (EEPROMS), which has direct-write cell capability is disclosed. The memory cell is utilized in the fabrication of non-volatile, direct-write EEPROM arrays with high integration density. A typical EEPROM array includes a plurality of elongated shallow trenches formed in a semiconductor substrate. Multiple direct-write EEPROM cells are disposed within each elongated trench such that each EEPROM cell shares a recall gate and a program gate with another cell in the same trench. Preferably, a silicon rich dielectric (such as silicon rich oxide) disposed between each floating gate and its associated programming and recall gates. Both common source diffusion and isolated source diffusion embodiments are disclosed. Further, various fabrication methods for the direct-write EEPROM arrays presented are described.