Loading patent…
AssigneeSiemens Aktiengesellschaft
InventorsKarl Knauer, Hans Joerg Pfleiderer
Estimating the term…
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.
Information storage apparatus comprising a doped semi-conductor substrate, a substrate surface and a substrate terminal, a memory element carried by said substrate including an MIS capacitor comprising an insulating layer carried on said surface over said doped zone and a capacitor electrode carried on said insulating layer, a contact zone in said substrate and a contact terminal carried on said contact zone, said contact zone in contact with said MIS capacitor and comprising a material which provides a diode effect where said zone contacts the doped material of said substrate, at least one of the values of the ratio of the dielectric constant of the insulating material to the thickness d of the insulating material, the surface density of substrate doping with respect to substrate surface in the area of the MIS capacitor, and the surface density of opposite substrate doping in an oppositely doped zone in the area of the MIS capacitor of the substrate is selected to respond to the application of a voltage across said substrate terminal and capacitor electrode to effect a local distribution of potential within said MIS capacitor, with respect to the contact area, which includes at least one increase from a minimum value to a maximum value.
A method of operating an information memory of the type which comprises a semiconductor substrate including a doped zone, an oppositely doped zone, a substrate surface and a substrate terminal, a memory element carried by the substrate including an MIS capacitor comprising an insulating layer carried on said surface over said doped zone and a capacitor electrode carried on said insulating layer, a contact zone in said substrate and a contact terminal carried on said contact zone, said contact zone in contact with said MIS capacitor and comprising a material which provides a diode effect where said zone contacts the doped material of said substrate, and wherein at least one of the values of the ratio of the dielectric constant .epsilon. of the insulating layer to the thickness d of the insulating layer, the surface density of substrate doping with respect to substrate surface in the area of the MIS capacitor, and the surface density of opposite substrate doping in the adjacent oppositely doped zone is selected to respond to the application of a voltage across said substrate terminal and said capacitor electrode to effect a local distribution of potential within said MIS capacitor, with respect to the contact area, which includes at least one increase from a minimum value to a maximum value, said method comprising the steps of:
Dependencies are inferred from the claim text.