# US 4,399,450 A · ROM With poly-Si to mono-Si diodes

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- Number: US 4,399,450 A
- Document ID: US4399450A
- Status: Granted
- Kind: A
- Application number: 06/219,059
- Filed: 1980-12-22
- Granted: 1983-08-16
- Earliest claimed: 1977-11-28
- Assignees: U.S. Philips Corporation
- Inventors: Jan Lohstroh
- Web page: https://patentgrep.com/patent/US4399450A

## CPC

- G11C 17/16: using electrically-fusible links
- G11C 17/06: using diode elements (G11C17/14 takes precedence)
- H10B 20/00: Read-only memory [ROM] devices
- H10D 62/40: Crystalline structures
- H10W 72/00: Interconnections or connectors in packages
- Y10S 257/91: Diode arrays, e.g. diode read-only memory array
- Y10S 257/926: Elongated lead extending axially through another elongated lead
- G11C: STATIC STORES (semiconductor memory devices H10B)
- H10B: ELECTRONIC MEMORY DEVICES
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## 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.

## Claims

### Claim 1

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.

### Claim 2 (depends on 1)

A semiconductor device as claimed in claim 1, wherein a metal layer is provided on the deposited semiconductor material above each of the rectifying junctions, which junctions form diodes.

### Claim 3 (depends on 2)

A semiconductor device as claimed in claim 2, wherein said metal layers are provided in the form of a number of metal tracks extending over at least substantially the whole length of a conductor track.

### Claim 4 (depends on 3)

A semiconductor device as claimed in claim 3, wherein said conductor tracks each comprise a double layer of a track of semiconductor material of the first conductivity type which extends over the whole length of the semiconductor track in the windows and over the insulating layer and a track of a metal which is provided over the whole length of the conductor track on the deposited semiconductor material.

### Claim 5 (depends on 1)

A semiconductor device as claimed in claim 1, wherein the surface concentration of said strip-shaped zones is at least 10.sup.19 impurities per cm.sup.3.

### Claim 6 (depends on 1)

A semiconductor device as claimed in claim 1, wherein the doping concentration of the polycrystalline material is at most 10.sup.18 impurities per cm.sup.3.

### Claim 7 (depends on 1)

A semiconductor device as claimed in claim 1, wherein metal tracks are provided above said semiconductor tracks, said metal tracks being insulated electrically from said conductor tracks and cross the same, and said metal tracks extend above and parallel to a strip-shaped zone formed in the body and are contacted in a number of places with said strip-shaped zones.