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:
Oct. 15, 1996
Filed:
Jun. 06, 1995
Manzur Gill, Arcola, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
An electrically-erasable, electrically-programmable, read-only-memory cell array is formed in pairs at a face of a semiconductor substrate (21). Each memory cell includes a source region (11) and a drain region (12) formed in a shared drain-column line (19), with a corresponding channel region in between. A Fowler-Nordheim tunnel-window (13a) is located opposite the channel over the source-column line (17) connected to source (11). A floating-gate conductor (13) includes a channel section (29) and a tunnel-window section (28). The floating-gate conductor is formed in two stages, the first stage forming the channel section (29) and the tunnel-window section (28) from a first-level polysilicon. This floating-gate channel section (29) is used as a self-alignment implant mask for the source (11) and drain (12) regions, such that the channel-junction edges are aligned with the corresponding edges of the channel section (29). A control-gate cenductor 14 is disposed over the floating-gate conductor (13), insulated by an intervening inter-level dielectric (26). The memory cell is programmed by hot-carrier injection from the channel to the floating-gate channel section (29), and erased by Fowler-Nordheim tunneling from the floating-gate tunnel-window section (28) through the tunnel window (13a). The program, erase and read regions of the cells are physically separate from each other, and the characteristics of each of those regions may be made optimum independently from each other.