# US 2014/0193979 A1 · Directional sio2 etch using plasma pre-treatment and high-temperature etchant deposition

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- Number: US 2014/0193979 A1
- Document ID: US20140193979A1
- Status: Published application
- Kind: A1
- Application number: 14/031,332
- Filed: 2013-09-19
- Published: 2014-07-10
- Earliest claimed: 2012-10-02
- Assignees: Applied Materials, Inc.
- Applicants: Applied Materials, Inc.
- Inventors: David T. OR; Joshua COLLINS; Mei CHANG
- Web page: https://patentgrep.com/patent/US20140193979A1

## CPC

- H10P 70/20: {Cleaning during device manufacture}
- 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

Methods for processing a substrate are described herein. Methods can include positioning a substrate with an exposed surface comprising a silicon oxide layer in a processing chamber, biasing the substrate, treating the substrate to roughen a portion of the silicon oxide layer, heating the substrate to a first temperature, exposing the exposed surface of the substrate to a plasma comprising ammonium fluoride to form one or more volatile products while maintaining the first temperature, and heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the volatile products.

## Claims

### Claim 1

A method, comprising:
positioning a substrate with an exposed surface comprising a silicon oxide layer in a processing chamber;
biasing the substrate;
treating the substrate to roughen a portion of the silicon oxide layer;
heating the substrate to a first temperature;
exposing the exposed surface of the substrate to a plasma comprising ammonium fluoride (NH4F) to form one or more volatile products; and
heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the volatile products.

### Claim 2 (depends on 1)

The method of claim 1, wherein the substrate has one or more vias or trenches formed on the exposed surface.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first temperature is a temperature of at least 65° C.

### Claim 4 (depends on 1)

The method of claim 1, wherein the first temperature is a temperature of between 70° C. and 90° C.

### Claim 5 (depends on 1)

The method of claim 1, wherein the second temperature is a temperature of greater than 100° C.

### Claim 6 (depends on 1)

The method of claim 1, wherein heating the substrate to a second temperature further comprises exposing the exposed surface of the substrate a low energy inert plasma.

### Claim 7 (depends on 1)

The method of claim 1, wherein the plasma comprising ammonium fluoride is formed remotely.

### Claim 8 (depends on 1)

The method of claim 1, wherein the plasma comprising ammonium fluoride is formed from a gas mixture comprising ammonia (NH3) and nitrogen trifluoride (NF3).

### Claim 9 (depends on 8)

The method of claim 8, wherein the gas mixture is a 1:1 ratio of ammonia (NH3) and nitrogen trifluoride (NF3) respectively.

### Claim 10 (depends on 1)

The method of claim 1, wherein the substrate is roughened by a low energy inert plasma.

### Claim 11

A method, comprising:
positioning a silicon-containing substrate in a processing chamber, the silicon-containing substrate comprising:
an exposed surface;
one or more microstructures formed in the exposed surface; and
a native oxide layer formed on the exposed surface;
biasing the substrate;
exposing the substrate to a low energy inert plasma to form amorphous silicon oxide on surface perpendicular to the flow of the low energy inert plasma;
heating the substrate to a first temperature;
exposing the surface of the substrate to a plasma comprising ammonium fluoride (NH4F) to form one or more volatile products; and
heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the volatile products.

### Claim 12 (depends on 11)

The method of claim 11, wherein the first temperature and the second temperature are within 10° C. of one another.

### Claim 13 (depends on 11)

The method of claim 11, wherein the first temperature is a temperature of at least 65° C.

### Claim 14 (depends on 11)

The method of claim 11, wherein the first temperature is a temperature of between 70° C. and 90° C.

### Claim 15 (depends on 11)

The method of claim 11, wherein the second temperature is a temperature of greater than 100° C.

### Claim 16 (depends on 11)

The method of claim 11, wherein heating the substrate to a second temperature further comprises exposing the exposed surface of the substrate a low energy inert plasma.

### Claim 17 (depends on 11)

The method of claim 11, wherein the plasma comprising ammonium fluoride is formed remotely.

### Claim 18 (depends on 11)

The method of claim 11, wherein the plasma comprising ammonium fluoride is formed from a gas mixture comprising ammonia (NH3) and nitrogen trifluoride (NF3).

### Claim 19 (depends on 18)

The method of claim 18, wherein the gas mixture is a 1:1 ratio of ammonia (NH3) and nitrogen trifluoride (NF3) respectively.

### Claim 20 (depends on 11)

The method of claim 11, wherein the plasma comprising ammonium fluoride is a non-sputtering plasma.