# US 10,374,084 B2 · Vertical channel devices and method of fabricating same

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- Number: US 10,374,084 B2
- Document ID: US10374084B2
- Status: Granted
- Kind: B2
- Application number: 15/980,611
- Filed: 2018-05-15
- Published: 2018-11-29
- Granted: 2019-08-06
- Earliest claimed: 2017-05-15
- Assignees: Imec Vzw
- Applicants: IMEC vzw
- Inventors: Juergen Boemmels
- Web page: https://patentgrep.com/patent/US10374084B2

## CPC

- H10D 30/63: Vertical IGFETs (H10D30/66 {, H10D30/6728, H10D30/689, H10D30/693} take precedence)
- H10B 10/12: {comprising a MOSFET load element}
- H10D 30/025: {of vertical IGFETs (of VDMOS H10D30/0291; of vertical TFTs H10D30/0318)}
- H10D 62/8162: {having quantum effects only in the vertical direction, i.e. layered structures having quantum effects solely resulting from vertical potential variation}
- H10D 84/0149: {Manufacturing their interconnections or electrodes, e.g. source or drain electrodes}
- H10D 84/016: {the components including vertical IGFETs}
- H10D 84/0186: {Manufacturing their interconnections or electrodes, e.g. source or drain electrodes}
- H10D 84/0195: {the components including vertical IGFETs}
- H10D 84/038: {using silicon technology, e.g. SiGe}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10B: ELECTRONIC MEMORY DEVICES

## Abstract

The disclosed technology generally relates to semiconductor devices and more particularly to vertical channel devices and a method of making the same. In one aspect, a method of forming vertical channel devices includes forming a first vertical channel structure extending from a first bottom electrode region and a second vertical channel structure extending from a second bottom electrode region. The first and the second vertical channel structures protrude from a dielectric layer covering the first and second bottom electrode regions. The method additionally comprises forming a first hole exposing the first bottom electrode region and a second hole exposing the second bottom electrode region, where the first and the second holes extending vertically through the dielectric layer. The method additionally includes forming a conductive pattern including a set of discrete pattern parts on the dielectric layer. Forming the conductive pattern includes forming a first pattern part including a first gate portion wrapping around a protruding portion of the first vertical channel structure, where a first bottom electrode contact portion is arranged in the second hole, and a first cross-coupling portion extending between the first bottom electrode contact portion and the first gate portion. Forming the conductive pattern additionally includes forming a second pattern part including a second gate portion wrapping around a protruding portion of the second vertical channel structure, where a second bottom electrode contact portion is arranged in the first hole, and a cross-coupling portion extending between the second bottom electrode contact portion and the second gate portion.

## Claims

### Claim 1

A method of forming a vertical channel device, the method comprising:
forming a first vertical channel structure extending from a first bottom electrode region and a second vertical channel structure extending from a second bottom electrode region, wherein the first and the second vertical channel structures protrude from a dielectric layer covering the first and second bottom electrode regions;
forming a first hole exposing the first bottom electrode region and a second hole exposing the second bottom electrode region, wherein the first and the second holes extend vertically through the dielectric layer;
forming a gate level conductor including at least one conductive layer, wherein the gate level conductor fills the first and the second holes and embeds protruding portions of the first and second vertical channel structures; and
forming a conductive pattern including a set of discrete pattern parts on the dielectric layer, wherein forming the conductive pattern includes:
forming a first pattern part including a first gate portion wrapping around a protruding portion of the first vertical channel structure, wherein a first bottom electrode contact portion is arranged in the second hole, and a first cross-coupling portion extends between the first bottom electrode contact portion and the first gate portion,
forming a second pattern part including a second gate portion wrapping around a protruding portion of the second vertical channel structure, wherein a second bottom electrode contact portion is arranged in the first hole, and a second cross-coupling portion extends between the second bottom electrode contact portion and the second gate portion,
forming an etch mask above the gate level conductor, wherein the etch mask includes a first discrete mask portion for defining the first pattern part and a second discrete mask portion for defining the second pattern part, and
etching the gate level conductor in a region exposed by the etch mask.

### Claim 2 (depends on 1)

The method according to claim 1, wherein forming the gate level conductor further comprises forming at least one conductive layer that fills the first and the second holes and embeds the protruding portions of the first and second vertical channel structures.

### Claim 3 (depends on 2)

The method according to claim 2, wherein forming the conductive pattern further comprises: forming an etch mask above the gate level conductor, wherein the etch mask includes a first discrete mask portion for defining the first pattern part and a second discrete mask portion for defining the second pattern part, and etching the gate level conductor in a region exposed by the etch mask.

### Claim 4 (depends on 3)

The method according to claim 3, wherein the gate level conductor includes:
forming a conformal metal contact layer on the protruding portions of the first and second vertical channel structures and in the first and second holes, and
forming a metal fill layer on the conformal metal contact layer and embedding the protruding portions of the first and second vertical channel structures.

### Claim 5 (depends on 4)

The method according to claim 4, wherein forming the metal fill layer comprises filling a remaining space in the first and the second holes.

### Claim 6 (depends on 3)

The method according to claim 3, wherein forming the gate level conductor includes forming a conformal work function metal layer prior to forming the first and the second holes, wherein the conformal work function metal layer is formed on the protruding portions of the first and second vertical channel structures and on the dielectric layer, and wherein forming the first and the second holes includes forming the first and second holes that extend through the conformal work function metal layer and further through the dielectric layer.

### Claim 7 (depends on 3)

The method according to claim 3, further comprising, prior to forming the etch mask, removing conductive layer portions from an upper portion of the first and the second vertical channel structures.

### Claim 8 (depends on 3)

The method according to claim 3, wherein forming the gate level conductor comprises completely covering the protruding portions of the first and second vertical channel structures.

### Claim 9 (depends on 8)

The method according to claim 8, further comprising, prior to forming the etch mask, reducing a thickness of the gate level conductor such that an upper portion of the first and second vertical channel structures protrudes from the gate level conductor.

### Claim 10 (depends on 1)

The method according to claim 1, further comprising, prior to forming the first and second holes, forming a gate dielectric layer covering the dielectric layer and the protruding portions of the first and the second vertical channel structures, wherein forming the first and the second holes includes forming the first and the second hole to extend through the gate dielectric layer and the dielectric layer.

### Claim 11 (depends on 1)

The method according to claim 1, further comprising embedding the first and second pattern parts in a dielectric fill layer, wherein a top portion of the first and the second vertical channel structures protrudes above the dielectric fill layer.

### Claim 12 (depends on 11)

The method according to claim 11, further comprising forming a first top electrode at the top portion of the first vertical channel structure and a second top electrode at the top portion of the second vertical channel structure.

### Claim 13 (depends on 1)

The method according to claim 1, further comprising forming a third vertical channel structure extending from the first bottom electrode region and a fourth vertical channel structure extending from the second bottom electrode region,
wherein the first gate portion of the first pattern part is formed as a common first gate portion wrapping around the first and third vertical channel structure, and
wherein the second gate portion of the second pattern part is formed as a common second gate portion wrapping around the second and fourth vertical channel structure.

### Claim 14 (depends on 13)

The method according to claim 13, further comprising forming a fifth vertical channel structure extending from the first bottom electrode region and a sixth vertical channel structure extending from the second bottom electrode region, wherein forming the conductive pattern includes:
forming a third pattern part including a gate portion wrapping around a protruding portion of the fifth vertical channel structure, and
forming a fourth pattern part including a gate portion wrapping around a protruding portion of the sixth vertical channel structure.
