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. 21, 1997
Filed:
Mar. 29, 1996
Applicant:
Inventors:
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 43 ; 437982 ; 437984 ;
Abstract
An SiO.sub.2 film and a PSG film are stacked on a semiconductor substrate. A contact hole is formed through the both films. An Si.sub.3 N.sub.4 film is formed on a side wall of the contact hole as a free ion Na.sup.+ blocking film. An aluminum wiring layer is formed in the contact hole. This arrangement prevents free ions Na.sup.+ from externally migrating through the SiO.sub.2 film and reaching a nonvolatile semiconductor memory cell during and after the formation of the contact hole.