# US 2018/0323075 A1 · SiN SPACER PROFILE PATTERNING

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- Number: US 2018/0323075 A1
- Document ID: US20180323075A1
- Status: Published application
- Kind: A1
- Application number: 16/036,635
- Filed: 2018-07-16
- Published: 2018-11-08
- Earliest claimed: 2016-11-14
- Assignees: Applied Materials, Inc.
- Applicants: Applied Materials, Inc.
- Inventors: Jungmin Ko; Tom Choi; Nitin Ingle; Kwang-Soo Kim; Theodore Wou
- Web page: https://patentgrep.com/patent/US20180323075A1

## CPC

- H10P 14/69215: {the material being a silicon oxide, e.g. SiO2}
- H10P 14/6304: {Formation by oxidation, e.g. oxidation of the substrate}
- H10P 50/283: {by chemical means}
- H10P 50/73: {using masks for insulating materials}
- H10P 76/4085: {characterised by the processes involved to create the masks}
- H10P 14/6522: {introduced into a nitride material, e.g. changing SiN to SiON}
- H10P 14/6532: {by exposure to a plasma}
- H10P 14/69433: {the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz}
- H10P 32/20: Diffusion for doping of insulating layers
- H10P 95/00: Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

Processing methods may be performed to form recesses in a semiconductor substrate. The methods may include oxidizing an exposed silicon nitride surface on a semiconductor substrate within a processing region of a semiconductor processing chamber. The methods may include forming an inert plasma within the processing region of the processing chamber. Effluents of the inert plasma may be utilized to modify the oxidized silicon nitride. A remote plasma may be formed from a fluorine-containing precursor to produce plasma effluents. The methods may include flowing the plasma effluents to the processing region of the semiconductor processing chamber. The methods may also include removing the modified oxidized silicon nitride from the semiconductor substrate.

## Claims

### Claim 1

An etching method comprising:
oxidizing an exposed nitride surface on a semiconductor substrate within a processing region of a semiconductor processing chamber;
forming an inert plasma within the processing region of the semiconductor processing chamber;
modifying at least part of the oxidized nitride with effluents of the inert plasma;
forming a remote plasma from a fluorine-containing precursor to produce plasma effluents;
flowing the plasma effluents to the processing region of the semiconductor processing chamber; and
removing the modified oxidized nitride from the semiconductor substrate.

### Claim 2 (depends on 1)

The etching method of claim 1, wherein the inert plasma comprises a hydrogen or helium plasma.

### Claim 3 (depends on 1)

The etching method of claim 1, wherein the inert plasma is formed from a bias power below about 100 W.

### Claim 4 (depends on 1)

The etching method of claim 1, wherein the surface of the exposed nitride on the semiconductor substrate is modified to a depth from the exposed surface within the semiconductor substrate of less than about 4 nm.

### Claim 5 (depends on 1)

The etching method of claim 1, wherein a pressure within the semiconductor processing chamber while forming the inert plasma and during the modifying is maintained below about 50 mTorr.

### Claim 6 (depends on 1)

The etching method of claim 1, wherein the remote plasma is formed in a region of the semiconductor processing chamber fluidly isolated from the processing region of the semiconductor processing chamber or is formed in a remote plasma unit fluidly coupled with the semiconductor processing chamber.

### Claim 7 (depends on 1)

The etching method of claim 1, wherein the semiconductor substrate is maintained at a temperature above or about 80° C. during the removal of the modified oxidized nitride.

### Claim 8 (depends on 7)

The etching method of claim 7, wherein removing the modified oxidized nitride exposes an unmodified portion of oxidized nitride, and wherein an etching selectivity of a modified portion of the oxidized nitride to the unmodified portion of the oxidized nitride is greater than or about 100:1.

### Claim 9 (depends on 1)

The etching method of claim 1, wherein the oxidizing comprises:
forming an oxygen-based plasma within the processing region of the semiconductor processing chamber; and
contacting the exposed nitride surface with plasma effluents of the oxygen-based plasma.

### Claim 10 (depends on 1)

The etching method of claim 1, wherein the nitride comprises silicon nitride.

### Claim 11 (depends on 1)

The etching method of claim 1, wherein the method produces a nitride material characterized by a height, and wherein the height across the nitride material varies across the nitride material by less than or about 10 nm.

### Claim 12

An etching method comprising:
oxidizing an exposed nitride material surface on a semiconductor substrate within a processing region of a semiconductor processing chamber to produce a region of oxide;
forming an inert plasma within the processing region of the semiconductor processing chamber;
modifying at least a portion of the region of oxide with effluents of the inert plasma;
contacting the modified oxide with plasma effluents of a fluorine-containing precursor; and
etching the modified oxide, wherein the oxidizing, modifying, contacting, and etching are all performed in the semiconductor processing chamber.

### Claim 13 (depends on 12)

The etching method of claim 12, wherein the etching is performed at a temperature of about 100° C.

### Claim 14 (depends on 12)

The etching method of claim 12, wherein the plasma effluents of the fluorine-containing precursor are formed in a remote region of the semiconductor processing chamber fluidly coupled with, and physically separated from, the processing region of the semiconductor processing chamber.

### Claim 15 (depends on 14)

The etching method of claim 14, wherein the plasma effluents of the fluorine-containing precursor are produced by a capacitively-coupled plasma at a power level of about 300 W.

### Claim 16 (depends on 14)

The etching method of claim 14, wherein the modified oxide is additionally contacted with a hydrogen-containing precursor.

### Claim 17 (depends on 16)

The etching method of claim 16, wherein the hydrogen-containing precursor bypasses the remote region of the semiconductor processing chamber, and wherein the hydrogen-containing precursor interacts with the plasma effluents of the fluorine-containing precursor subsequent to the plasma effluents of the fluorine-containing precursor exiting the remote region of the semiconductor processing chamber.

### Claim 18

An etching method comprising:
forming an oxygen-containing plasma within a processing region of a semiconductor processing chamber;
oxidizing an exposed silicon-containing surface on a semiconductor substrate within the processing region of the semiconductor processing chamber to form a region of silicon oxide;
forming an inert plasma within the processing region of the semiconductor processing chamber, wherein the inert plasma comprises a hydrogen or helium plasma formed by a bias power of less than 1,000 W;
modifying at least a portion of the oxidized silicon-containing surface with effluents of the inert plasma;
forming a plasma of a fluorine-containing precursor in a remote region of the semiconductor processing chamber that is separated from the processing region of the semiconductor processing chamber by a showerhead;
contacting the modified, oxidized silicon-containing surface with plasma effluents of the fluorine-containing precursor; and
etching the modified, oxidized silicon-containing surface at a temperature of about 100° C., wherein the oxidizing, modifying, contacting, and etching are all performed in the semiconductor processing chamber, and wherein no solid byproducts are produced during the etching.

### Claim 19 (depends on 18)

The etching method of claim 18, wherein the remote region of the semiconductor processing chamber is a region defined within the semiconductor processing chamber.

### Claim 20 (depends on 18)

The etching method of claim 18, wherein the remote region of the semiconductor processing chamber is a region external to the semiconductor processing chamber, but fluidly coupled with an inlet to the semiconductor processing chamber.