# US 2018/0323068 A1 · Methods of Forming Tungsten Pillars

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- Number: US 2018/0323068 A1
- Document ID: US20180323068A1
- Status: Published application
- Kind: A1
- Application number: 15/969,119
- Filed: 2018-05-02
- Published: 2018-11-08
- Earliest claimed: 2017-05-02
- Assignees: Applied Materials, Inc.
- Applicants: Applied Materials, Inc.
- Inventors: Abhijit Basu Mallick; Pramit Manna; Yihong Chen; Ziqing Duan; Rui Cheng; Shishi Jiang
- Web page: https://patentgrep.com/patent/US20180323068A1

## CPC

- H10P 76/4088: {Processes for improving the resolution of the masks}
- H10P 76/405: {characterised by their composition, e.g. multilayer masks}
- H10P 76/4083: {characterised by their behaviours during the lithography processes, e.g. soluble masks or redeposited masks}
- H10P 76/4085: {characterised by the processes involved to create the masks}
- H10W 20/056: {by filling conductive material into holes, grooves or trenches}
- H10W 20/066: {by forming silicides of refractory metals}
- H10P 32/30: Diffusion for doping of conductive or resistive layers
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Methods of forming self-aligned patterns are described. A film material is deposited on a patterned film to fill and cover features formed by the patterned film. The film material is recessed to a level below the top of the patterned film. The recessed film is converted to a metal film by exposure to a metal precursor followed by volumetric expansion of the metal film.

## Claims

### Claim 1

A processing method comprising:
providing a substrate surface with a patterned film forming at least one feature, the at least one feature extending a depth from a top surface of the patterned film to a bottom surface, the at least one feature having a width defined by a first sidewall and a second sidewall;
depositing a film on the patterned film to fill the at least one feature and extend above the top surface of the patterned film;
recessing the film to lower a top of the film to a height equal to or below the top surface of the patterned film to form a recessed film;
converting the recessed film to a tungsten film; and
expanding the tungsten film to form pillars extending from the at least one feature.

### Claim 2 (depends on 1)

The method of claim 1, wherein the film comprises amorphous silicon.

### Claim 3 (depends on 2)

The method of claim 2, wherein depositing the film comprising exposing the substrate surface to a precursor comprising one or more of silane, disilane, trisilane or tetrasilane.

### Claim 4 (depends on 3)

The method of claim 3, wherein depositing the film occurs at a temperature in the range of about 300° C. to about 550° C.

### Claim 5 (depends on 4)

The method of claim 4, wherein depositing the film occurs at a pressure in the range of about 10 T to about 600 T.

### Claim 6 (depends on 5)

The method of claim 5, wherein depositing the film occurs without a co-reactant for the precursor.

### Claim 7 (depends on 3)

The method of claim 3, wherein depositing the film occurs at a temperature in the range of about −100° C. to about 50° C.

### Claim 8 (depends on 7)

The method of claim 7, wherein depositing the film occurs at a pressure in the range of about 1 T to about 10 T.

### Claim 9 (depends on 8)

The method of claim 8, wherein depositing the film occurs with an RF plasma having a power in the range of about 10 W to about 200 W.

### Claim 10 (depends on 9)

The method of claim 9, wherein depositing the film occurs without a co-reactant for the precursor.

### Claim 11 (depends on 1)

The method of claim 1, wherein recessing the film comprises etching the film.

### Claim 12 (depends on 11)

The method of claim 11, wherein etching the film comprises a reactive ion etch process using a bromine based etchant.

### Claim 13 (depends on 11)

The method of claim 11, wherein recessing the film comprises exposing the film to a hydrogen plasma or hydrogen radicals.

### Claim 14 (depends on 1)

The method of claim 1, wherein converting the recessed film to a tungsten film comprises exposing the recessed film to WF6.

### Claim 15 (depends on 14)

The method of claim 14, wherein exposure to WF6 occurs at a temperature in the range of about 300° C. to about 550° C. and a pressure in the range of about 10 T to about 100 T.

### Claim 16 (depends on 15)

The method of claim 15, wherein substantially all of the recessed film is converted to tungsten.

### Claim 17 (depends on 1)

The method of claim 1, wherein expanding the tungsten film comprises oxidizing the tungsten film.

### Claim 18 (depends on 17)

The method of claim 17, wherein the pillars extend substantially straight up from the feature.

### Claim 19

A processing method comprising:
providing a substrate surface with a patterned film forming at least one feature, the at least one feature extending a depth from a top surface to a bottom surface, the at least one feature having a width defined by a first sidewall and a second sidewall;
exposing the substrate surface to a silicon precursor comprising one or more of silane, disilane, trisilane or tetrasilane to deposit an amorphous silicon film by thermal decomposition on the substrate surface to fill the at least one feature and extend above the substrate surface;
etching the amorphous silicon film with a hydrogen plasma or hydrogen radicals to recess the amorphous silicon film to lower a top of the amorphous silicon film to a height equal to or below the top surface of the patterned film to form a recessed amorphous silicon film;
exposing the recessed amorphous silicon film to a tungsten precursor to react with the recessed amorphous silicon film to convert substantially all of the amorphous silicon film to a tungsten film; and
oxidizing the tungsten film to expand the tungsten film to form tungsten pillars that extending substantially straight up from the at least one feature.

### Claim 20

A processing method comprising:
providing a substrate surface with a patterned film forming at least one feature, the at least one feature extending a depth from a top surface to a bottom surface, the at least one feature having a width defined by a first sidewall and a second sidewall;
exposing the substrate surface to a silicon precursor comprising one or more of silane, disilane, trisilane or tetrasilane to deposit an amorphous silicon film by thermal decomposition on the substrate surface to fill the at least one feature and extend above the top surface of the patterned film, the thermal decomposition occurring without a silicon co-reactant and at a temperature in the range of about 300° C. to about 550° C. without a plasma or at a temperature in the range of about −100° C. to about 50° C. with a plasma;
etching the amorphous silicon film with a hydrogen plasma or hydrogen radicals to recess the amorphous silicon film to lower a top of the amorphous silicon film to a height equal to or below the top surface of the patterned film to form a recessed amorphous silicon film;
exposing the recessed amorphous silicon film to a tungsten precursor comprising WF6 at a temperature in the range of about 300° C. to about 550° C. to react with the recessed amorphous silicon film to convert substantially all of the amorphous silicon film to a tungsten film; and
oxidizing the tungsten film to expand the tungsten film to form tungsten pillars that extending substantially straight up from the at least one feature.