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:
May. 06, 1986
Filed:
Oct. 11, 1979
Applicant:
Inventor:
G R Rao, Houston, TX (US);
Assignee:
Texas Instruments Incorporated, Dallas, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; G11C / ;
U.S. Cl.
CPC ...
357 236 ; 357 2311 ; 357 41 ; 365149 ;
Abstract
An MOS/LSI type dynamic RAM with single 5 V supply and grounded substrate employs a guard ring surrounding the cell array to prevent pattern sensitivity in testing. The guard ring is an N+ region biased at Vdd over a deep P+ region in a P-substrate, producing a built-in electric field which attracts diffusing minority carriers into a collecting junction. A standard process for making double-level poly memory devices is modified by adding a P+ implant and deep drive-in prior to field oxidation.