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:
Aug. 06, 1996
Filed:
Aug. 29, 1994
Applicant:
Inventors:
Scott S Roth, Austin, TX (US);
Howard C Kirsch, Austin, TX (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 43 ; 437191 ; 437927 ;
Abstract
A floating gate (51) is formed to have a cavity (52) that increases the capacitive coupling between the floating gate (51) and a control gate for the memory cell. The memory cell may be used in EPROM, EEPROM, and flash EEPROM arrays and may be programmed and erased by hot carrier injection, Fowler-Nordheim tunneling or the like. The process sequence for forming the cavity (52) of the floating gate (51) has good process margin allowing some lithographic misalignment. In one embodiment, a multi-tiered floating gate may be formed. The multi-tier structure allows the capacitive coupling to further increase without occupying more area.