# US 12,218,227 B2 · Semiconductor structure

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- Number: US 12,218,227 B2
- Document ID: US12218227B2
- Status: Granted
- Kind: B2
- Application number: 18/447,932
- Filed: 2023-08-10
- Published: 2023-12-07
- Granted: 2025-02-04
- Earliest claimed: 2021-05-27
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Company, Ltd.
- Inventors: Shih-Hao Lin; Chia-Hung Chou; Chih-Hsuan Chen; Ping-En Cheng; Hsin-Wen Su; Chien-Chih Lin; Szu-Chi Yang
- Web page: https://patentgrep.com/patent/US12218227B2

## CPC

- H10D 30/0243: {using dummy structures having essentially the same shapes as the semiconductor bodies, e.g. to provide stability}
- H10D 64/017: {using dummy gates in processes wherein at least parts of the final gates are self-aligned to the dummy gates, i.e. replacement gate processes}
- H10B 10/12: {comprising a MOSFET load element}
- H10D 30/0195: {forming inner spacers between adjacent channels, e.g. changing their shapes or sizes}
- H10D 30/508: {characterised by the relative sizes, shapes or dispositions of the inner spacers}
- H10D 30/6211: {having fin-shaped semiconductor bodies integral with the bulk semiconductor substrates}
- H10D 62/121: {oriented parallel to substrates}
- H10D 64/018: {Spacers formed inside holes at the prospective gate locations, e.g. holes left by removing dummy gates}
- H10D 64/021: {using multiple gate spacer layers, e.g. bilayered sidewall spacers}
- H10D 64/685: {being perpendicular to the channel plane}
- H10D 64/691: {comprising metallic compounds, e.g. metal oxides or metal silicates (insulators comprising nitrogen H10D64/693)}
- H10D 84/0147: {Manufacturing their gate sidewall spacers}
- H10D 84/0158: {the components including FinFETs}
- H10D 84/038: {using silicon technology, e.g. SiGe}
- B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
- H10D 30/797: {being in source or drain regions, e.g. SiGe source or drain}
- H10D 62/822: comprising only Group IV materials heterojunctions, e.g. Si/Ge heterojunctions
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10B: ELECTRONIC MEMORY DEVICES
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

A semiconductor structure includes substrate, semiconductor layers, source/drain features, metal oxide layers, and a gate structure. The semiconductor layers extend in an X-direction and over the substrate. The semiconductor layers are spaced apart from each other in a Z-direction. The source/drain features are on opposite sides of the semiconductor layers in the X-direction. The metal oxide layers cover bottom surfaces of the semiconductor layers. The gate structure wraps around the semiconductor layers and the metal oxide layers. The metal oxide layers are in contact with the gate structure.

## Claims

### Claim 1

A semiconductor structure, comprising:
a substrate;
semiconductor layers extending in an X-direction and over the substrate, wherein the semiconductor layers are spaced apart from each other in a Z-direction;
source/drain features on opposite sides of the semiconductor layers in the X-direction;
metal oxide layers covering bottom surfaces of the semiconductor layers; and
a gate structure wrapping around the semiconductor layers and the metal oxide layers, wherein center portions of the metal oxide layers covering the bottom surfaces of the semiconductor layers are in contact with the gate structure.

### Claim 2 (depends on 1)

The semiconductor structure of claim 1, further comprising:
inner spacers between the semiconductor layers in the Z-direction, wherein the inner spacers are in contact with the metal oxide layers.

### Claim 3 (depends on 1)

The semiconductor structure of claim 1, wherein the metal oxide layers comprise lanthanum, gadolinium, yttrium, and combinations thereof.

### Claim 4 (depends on 1)

The semiconductor structure of claim 1, wherein a thickness of the metal oxide layers is in a range from about 1 nanometer to about 5 nanometers.

### Claim 5 (depends on 1)

The semiconductor structure of claim 1, wherein portions of the source/drain features are between the semiconductor layers in the Z-direction, wherein the portions of the source/drain features are in contact with the metal oxide layers.

### Claim 6 (depends on 1)

The semiconductor structure of claim 1, wherein the gate structure further comprising:
an interfacial layer wrapping around the semiconductor layers and the metal oxide layers;
a gate dielectric layer wrapping around the interfacial layer; and
a gate electrode wrapping around the gate dielectric layer.

### Claim 7

A semiconductor structure, comprising:
a substrate;
a first semiconductor layer over the semiconductor substrate in a Z-direction;
a second semiconductor layer over and spaced apart from the first semiconductor layer in the Z-direction;
source/drain features on opposite sides of the first semiconductor layer and the second semiconductor layer in an X-direction;
rare earth oxide layers on top surfaces and bottom surfaces of the first semiconductor layer and the second semiconductor layer; and
a gate structure wrapping around center portions of the first semiconductor layer, the second semiconductor layer, and the rare earth oxide layers, wherein the center portions of the rare earth oxide layers are in contact with the gate structure in the Z-direction.

### Claim 8 (depends on 7)

The semiconductor structure of claim 7, wherein the rare earth oxide layers comprise lanthanum oxide, gadolinium oxide, yttrium oxide, and combinations thereof.

### Claim 9 (depends on 7)

The semiconductor structure of claim 7, wherein the rare earth oxide layers comprise a crystal structure of a hexagonal phase.

### Claim 10 (depends on 7)

The semiconductor structure of claim 7, further comprising:
gate spacers on opposite sides of the gate structure and overlapping the rare earth oxide layers.

### Claim 11 (depends on 7)

The semiconductor structure of claim 7, wherein portions of the source/drain features are between the rare earth oxide layers in the Z-direction.

### Claim 12 (depends on 11)

The semiconductor structure of claim 11, wherein the portions of the source/drain features comprise convex sidewalls.

### Claim 13

A semiconductor structure, comprising:
a substrate;
semiconductor layers extending in an X-direction and over the substrate, wherein the semiconductor layers are spaced apart from each other in a Z-direction;
source/drain features on opposite sides of the semiconductor layers in the X-direction;
metal oxide layers covering top surfaces and bottom surfaces of the semiconductor layers;
inner spacers between the metal oxide layers in the Z-direction; and
a gate structure wrapping around the semiconductor layers and the metal oxide layers, wherein center portions of the metal oxide layers are in contact with the gate structure in the Z-direction.

### Claim 14 (depends on 13)

The semiconductor structure of claim 13, wherein the metal oxide layers are fabricated by atom layer deposition.

### Claim 15 (depends on 13)

The semiconductor structure of claim 13, further comprising:
gate spacers on opposite sides of the gate structure and over a topmost surface of the semiconductor layers.

### Claim 16 (depends on 13)

The semiconductor structure of claim 13, wherein the inner spacers comprise convex sidewalls in contact with the gate structure.

### Claim 17 (depends on 13)

The semiconductor structure of claim 13, wherein portions of the source/drain features are between the rare earth oxide layers in the Z-direction.

### Claim 18 (depends on 17)

The semiconductor structure of claim 17, wherein the portions of the source/drain features are in contact with the rare earth oxide layers.

### Claim 19 (depends on 17)

The semiconductor structure of claim 17, wherein the portions of the source/drain features are separated from the rare earth oxide layers by the inner spacers.

### Claim 20 (depends on 13)

The semiconductor structure of claim 13, metal oxide layers comprise a metal material selected from the group consisting of lanthanum, gadolinium, yttrium, and combinations thereof.