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:
Dec. 20, 1977
Filed:
Sep. 15, 1976
Karl Knauer, Gauting, DT;
Hans Joerg Pfleiderer, Zorneding, DT;
Siemens Aktiengesellschaft, Berlin & Munich, DT;
Abstract
An information memory for storing information in the form of electric charge carriers has at least one dynamic storage element which is arranged upon a surface of at least one substrate made of semiconductor material and doped with a given basic type doping. The substrate connection is included and the memory comprises at least one MIS capacitor. Upon the substrate surface at least one electrically insulating layer is present which carries at least one capacitor electrode. The dynamic storage element comprises the MIS capacitor or an adjacent arrangement of several MIS capacitors, separated from one another by, at the most, narrow distances and comprises at least one contact area at the substrate surface which is provided with an externally accessible ohmic terminal contact, and which contacts at least the margin of the MIS capacitor or t least one of the MIS capacitors, nd which contains material having the basic type of doping. Within the electrically insulating layer, within the MIS capacitor or capacitors, the values of the numerical ratio .epsilon./d--whereby .epsilon. is the dielectric constant and d is the layer thickness of the electrically insulating layer--and/or the values of the surface density of the basic type of doping of the substrate in the area or in the areas of the MIS capacitor or capacitors and/or the values of the surface density, with respect to the surface of the substrate, of and adjacent to the substrate and doped opposite to the type of doping of the substrate layer, are selected differently with respect to location in such a way that, by the way of applying an electrode voltage, which may be given within a wide range between the substrate terminal and electrode, the local distribution of the amounts of the potential maximum between the range or within the ranges of the MIS capacitor or capacitor, comprises, laterally away from the contact area beginning at the side of the contact area, at least one increase from a minimum value to a maximum value.