# US 10,872,778 B2 · Systems and methods utilizing solid-phase etchants

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- Number: US 10,872,778 B2
- Document ID: US10872778B2
- Status: Granted
- Kind: B2
- Application number: 16/028,928
- Filed: 2018-07-06
- Published: 2020-01-09
- Granted: 2020-12-22
- Earliest claimed: 2018-07-06
- Assignees: Applied Materials, Inc.
- Applicants: Applied Materials, Inc.
- Inventors: Zhijun Chen; Chia-Ling Kao; Anchuan Wang; Nitin Ingle
- Web page: https://patentgrep.com/patent/US10872778B2

## CPC

- H10P 50/282: {of inorganic materials}
- H10P 50/283: {by chemical means}
- H10D 64/015: {removing at least parts of gate spacers, e.g. disposable spacers}
- H10P 14/69215: {the material being a silicon oxide, e.g. SiO2}
- H10P 50/28: of insulating materials
- H10P 72/0418: {for etching}
- H10W 20/072: {of dielectric parts comprising air gaps}
- H10W 20/46: comprising air gaps
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Exemplary etching methods may include flowing a hydrogen-containing precursor into a substrate processing region of a semiconductor processing chamber. The methods may include flowing a fluorine-containing precursor into the substrate processing region. The methods may include contacting a substrate housed in the substrate processing region with the hydrogen-containing precursor and the fluorine-containing precursor. The substrate may define a trench. A spacer may be formed along a sidewall of the trench, and the spacer may include a plurality of layers including a first layer of a carbon-containing material, a second layer of an oxygen-containing material, and a third layer of a carbon-containing material. The second layer of the spacer may be disposed between the first layer and third layer of the spacer. The methods may also include removing the oxygen-containing material.

## Claims

### Claim 1

An etching method comprising:
flowing a hydrogen-containing precursor into a substrate processing region of a semiconductor processing chamber;
flowing a fluorine-containing precursor into the substrate processing region, wherein the hydrogen-containing precursor is flowed for a first period of time prior to flowing the fluorine-containing precursor;
contacting a substrate housed in the substrate processing region with the hydrogen-containing precursor and the fluorine-containing precursor, wherein the substrate defines a trench, wherein a spacer is formed along a sidewall of the trench, wherein the spacer includes a plurality of layers including a first layer of a carbon-containing material, a second layer of an oxygen-containing material, and a third layer of a carbon-containing material, and wherein the second layer of the spacer is disposed between the first layer and third layer of the spacer, wherein a solid layer of the hydrogen-containing precursor is formed over the second layer of the spacer prior to flowing the fluorine-containing precursor; and
removing the oxygen-containing material.

### Claim 2 (depends on 1)

The etching method of claim 1, wherein the hydrogen-containing precursor is maintained fluidly isolated from a plasma formable within the semiconductor processing chamber in a remote plasma region of the semiconductor processing chamber.

### Claim 3 (depends on 1)

The etching method of claim 1, wherein the hydrogen-containing precursor comprises water vapor.

### Claim 4 (depends on 1)

The etching method of claim 1, wherein the fluorine-containing precursor comprises anhydrous hydrogen fluoride.

### Claim 5 (depends on 1)

The etching method of claim 1, wherein the oxygen-containing material is characterized by a width of less than or about 5 nm.

### Claim 6 (depends on 1)

The etching method of claim 1 wherein the fluorine-containing precursor is flowed for a second period of time during which the removal occurs, and wherein the flow of the fluorine-containing precursor is halted subsequent the second period of time.

### Claim 7 (depends on 6)

The etching method of claim 6, wherein the hydrogen-containing precursor is continually flowed during the first period of time and the second period of time.

### Claim 8 (depends on 6)

The etching method of claim 6, wherein the substrate processing region is purged subsequent the second period of time.

### Claim 9 (depends on 8)

The etching method of claim 8, wherein a second cycle of the etching method is performed to remove additional oxygen-containing material.

### Claim 10 (depends on 1)

The etching method of claim 1, wherein the substrate processing region is maintained plasma-free during the etching method.

### Claim 11

A removal method comprising:
flowing water vapor into a substrate processing region at a temperature below or about 0° C.;
forming a solid layer of water on a substrate housed in the substrate processing region, wherein the substrate defines a trench, wherein a spacer is formed along a sidewall of the trench, wherein the spacer includes a plurality of lateral layers including a first layer of a carbon-containing material adjacent a sidewall of the trench, a second layer comprising an oxygen-containing material, and a third layer of a carbon-containing material, wherein the second layer of the spacer is disposed between the first layer of the spacer and third layer of the spacer, and wherein the solid layer of water is formed on an exposed surface of each layer of the spacer;
flowing a fluorine-containing precursor into the substrate processing region of a semiconductor processing chamber;
permeating the solid layer of water with the fluorine-containing precursor; and
removing the second layer of the spacer.

### Claim 12 (depends on 11)

The removal method of claim 11, wherein the fluorine-containing precursor is delivered into the substrate processing region of the semiconductor processing chamber subsequent forming a solid layer of water on the substrate.

### Claim 13 (depends on 11)

The removal method of claim 11, wherein the water vapor is delivered into the substrate processing region at a temperature above or about −40° C., and wherein a partial pressure of the water vapor during the flowing is maintained above or about 1 Torr.

### Claim 14 (depends on 11)

The removal method of claim 11, wherein the second layer of the spacer further comprises carbon or nitrogen with the oxygen-containing material.

### Claim 15 (depends on 11)

The removal method of claim 11, wherein the first layer of the spacer and the third layer of the spacer comprise silicon nitride or silicon carbon nitride.

### Claim 16 (depends on 11)

The removal method of claim 11, wherein the fluorine-containing precursor is flowed for a period of time during which the removal occurs, and wherein the flow of the fluorine-containing precursor is halted subsequent the period of time.

### Claim 17 (depends on 11)

The removal method of claim 11, wherein the fluorine-containing precursor is anhydrous hydrogen fluoride, and wherein the substrate processing region is maintained plasma-free during the removal method.

### Claim 18

An etching method comprising:
flowing a hydrogen-containing precursor into a substrate processing region of a semiconductor processing chamber;
flowing anhydrous hydrogen fluoride into the substrate processing region;
contacting a substrate housed in the substrate processing region with the anhydrous hydrogen fluoride and the hydrogen-containing precursor, wherein the substrate defines a trench, wherein a spacer is formed along a sidewall of the trench, wherein the spacer includes a plurality of lateral layers including a first layer of a carbon-containing material adjacent a sidewall of the trench, a second layer comprising an oxygen-containing material, and a third layer of a nitrogen-containing material, wherein the second layer of the spacer is disposed between the first layer of the spacer and third layer of the spacer, and wherein the hydrogen-containing precursor forms a solid layer of material along a surface of the substrate and the second layer of the spacer; and
removing the second layer of the spacer.

### Claim 19 (depends on 18)

The etching method of claim 18, wherein the hydrogen-containing precursor is flowed at a temperature below or about −20° C.

### Claim 20 (depends on 18)

The etching method of claim 18, wherein the anhydrous hydrogen fluoride is delivered into the substrate processing region of the semiconductor processing chamber subsequent forming a solid layer of material along the surface of the substrate.