# US 2021/0242402 A1 · Cbram with controlled bridge location

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- Number: US 2021/0242402 A1
- Document ID: US20210242402A1
- Status: Published application
- Kind: A1
- Application number: 17/233,968
- Filed: 2021-04-19
- Published: 2021-08-05
- Earliest claimed: 2019-07-01
- Assignees: International Business Machines Corporation
- Applicants: International Business Machines Corporation
- Inventors: Jianshi Tang; Takashi Ando; Reinaldo Vega; Praneet Adusumilli
- Web page: https://patentgrep.com/patent/US20210242402A1

## CPC

- H10N 70/063: {by etching of pre-deposited switching material layers, e.g. lithography}
- H10N 70/245: {the species being metal cations, e.g. programmable metallization cells}
- H10B 63/80: {Arrangements comprising multiple bistable or multi-stable switching components of the same type on a plane parallel to the substrate, e.g. cross-point arrays}
- H10N 70/068: {by processes specially adapted for achieving sub-lithographic dimensions, e.g. using spacers}
- H10N 70/24: {based on migration or redistribution of ionic species, e.g. anions, vacancies}
- H10N 70/8265: {on sidewalls of dielectric structures, e.g. mesa-shaped or cup-shaped devices}
- H10N 70/8833: {Binary metal oxides, e.g. TaOx}
- H10N 70/826: {adapted for essentially vertical current flow, e.g. sandwich or pillar type devices}
- H10N 70/8416: {adapted for supplying ionic species}
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B: ELECTRONIC MEMORY DEVICES

## Abstract

Devices with settable resistance and methods of forming the same include forming vertical dielectric structures from heterogeneous dielectric materials on a first electrode. A second electrode is formed on the vertical dielectric structures.

## Claims

### Claim 1

A conductive bridge random access memory (CBRAM) device, comprising:
a first electrode;
a plurality of vertical dielectric structures formed from heterogeneous dielectric materials on the first electrode; and
a second electrode on the plurality of vertical dielectric structures.

### Claim 2 (depends on 1)

The CBRAM device of claim 1, wherein the plurality of vertical dielectric structures includes a mandrel, formed from a first dielectric material, that partially covers the first electrode.

### Claim 3 (depends on 2)

The CBRAM device of claim 2, wherein the plurality of vertical dielectric structures further includes a first sidewall spacer, formed from a second dielectric material, different from the first dielectric material, on a sidewall of the mandrel.

### Claim 4 (depends on 3)

The CBRAM device of claim 3, wherein the plurality of vertical dielectric structures further includes a second sidewall spacer, formed from a third dielectric material, different from the second dielectric material, on a sidewall of the second sidewall spacer.

### Claim 5 (depends on 4)

The CBRAM device of claim 4, wherein the plurality of vertical dielectric structures further includes a third sidewall spacer, formed from the second dielectric material, on a sidewall of the second sidewall spacer.

### Claim 6 (depends on 3)

The CBRAM device of claim 3, wherein the plurality of vertical dielectric structures further includes an interlayer dielectric, formed from the first dielectric material, on a sidewall of the first sidewall spacer.

### Claim 7 (depends on 1)

The CBRAM device of claim 1, further comprising spacer remnants on a sidewall of the first electrode that correspond to materials of the plurality of vertical dielectric structures.

### Claim 8 (depends on 7)

The CBRAM devices of claim 7, wherein the spacer remnants comprise three layers of dielectric material positioned side-by-side.

### Claim 9 (depends on 1)

The CBRAM device of claim 1, wherein the second electrode is formed from a conductive material that undergoes electromigration when a current is applied.

### Claim 10 (depends on 9)

The CBRAM device of claim 9, wherein the second electrode is formed from a material selected from the group consisting of silver, copper, and silver/copper alloys.

### Claim 11

A conductive bridge random access memory (CBRAM) device, comprising:
a first electrode;
a plurality of vertical dielectric structures formed from heterogeneous dielectric materials on the first electrode, including a mandrel formed from a first dielectric material, that partially covers the first electrode;
spacer remnants on a sidewall of the first electrode that correspond to materials of the plurality of vertical dielectric structures; and
a second electrode on the plurality of vertical dielectric structures, formed from a material that undergoes electromigration when a current is applied.

### Claim 12 (depends on 11)

The CBRAM device of claim 11, wherein the plurality of vertical dielectric structures further includes a first sidewall spacer, formed from a second dielectric material, different from the first dielectric material, on a sidewall of the mandrel.

### Claim 13 (depends on 12)

The CBRAM device of claim 12, wherein the plurality of vertical dielectric structures further includes a second sidewall spacer, formed from a third dielectric material, different from the second dielectric material, on a sidewall of the second sidewall spacer.

### Claim 14 (depends on 13)

The CBRAM device of claim 13, wherein the plurality of vertical dielectric structures further includes a third sidewall spacer, formed from the second dielectric material, on a sidewall of the second sidewall spacer.

### Claim 15 (depends on 12)

The CBRAM device of claim 12, wherein the plurality of vertical dielectric structures further includes an interlayer dielectric, formed from the first dielectric material, on a sidewall of the first sidewall spacer.

### Claim 16 (depends on 11)

The CBRAM device of claim 11, wherein the second electrode is formed from a material selected from the group consisting of silver, copper, and silver/copper alloys.

### Claim 17 (depends on 11)

The CBRAM devices of claim 11, wherein the spacer remnants comprise three layers of dielectric material positioned side-by-side.

### Claim 18

A conductive bridge random access memory (CBRAM) device, comprising:
a first electrode;
a mandrel, formed from a first dielectric material, that partially covers the first electrode;
a first sidewall spacer, formed from a second dielectric material that is different from the first dielectric material, on a sidewall of the mandrel;
a second sidewall spacer, formed from a third material that is different from the second dielectric material, on a sidewall of the first sidewall spacer;
a third sidewall spacer, formed from the second dielectric material, on a sidewall of the second sidewall spacer;
an interlayer dielectric layer, formed from the first dielectric material, on a sidewall of the third sidewall spacer;
a second electrode on the mandrel, the first sidewall spacer, the second sidewall spacer, and the third sidewall spacer; and
spacer remnants on a sidewall of the first electrode that include the second dielectric material and the third dielectric material.

### Claim 19 (depends on 18)

The CBRAM device of claim 18, wherein the first dielectric material is selected from the group consisting of aluminum oxide and silicon nitride, wherein the second dielectric material is selected from the group consisting of hafnium dioxide, tantalum oxide, and titanium oxide, wherein the third dielectric material is an oxide that is different from the second dielectric material, and wherein the second electrode is formed from a material selected from the group consisting of silver, copper, and silver/copper alloys.

### Claim 20 (depends on 18)

The CBRAM device of claim 18, wherein the spacer remnants comprise three layers of dielectric material positioned side-by-side.