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US 4,399,450 AGranted
ROM With poly-Si to mono-Si diodes
AssigneeU.S. Philips Corporation
InventorJan Lohstroh
Life of this patent
Estimating the term…
Abstract
In a diode matrix of a permanent memory (ROM) the word line and bit line system is formed by a system of strip-shaped zones of one conductivity type provided in the silicon body and in the another system is formed by polycrystalline silicon tracks of the opposite conductivity type provided on the surface and forming mono-poly p-n junctions with the strip-shaped zones. High packing density and high speed are obtained.
Claims7
A semiconductor device having a permanent memory, comprising:
- a semiconductor body having a surface-adjoining surface region of mainly a first conductivity type;
- a number of juxtaposed, parallel strip-shaped surface zones of the second conductivity type provided on said region;
- said surface being covered with an insulating layer;
- a number of juxtaposed, parallel strip-shaped conductor tracks provided on said insulating layer which cross said strip-shaped surface zones;
- said conductor tracks at the area of the crossings being connected to said strip-shaped zones by a rectifying junction through windows in said insulating layer depending on the information stored in the memory, characterized in that,
- at least parts of said conductor tracks are formed by semiconductor material deposited at least on the surface of said semiconductor body in the windows, which material is of the first conductivity type opposite to the conductivity type of said strip-shaped zones, forming said rectifying junctions at the area of said windows in the form of p-n junctions,
- said semiconductor material deposited in said window having a polycrystalline structure;
- the doping concentration of the deposited semiconductor material being lower than the surface concentration of said strip-shaped zones in said semiconductor body.
5 more elements
Dependencies are inferred from the claim text.