# US 10,768,526 B2 · Method of forming patterns

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- Number: US 10,768,526 B2
- Document ID: US10768526B2
- Status: Granted
- Kind: B2
- Application number: 16/111,522
- Filed: 2018-08-24
- Published: 2018-12-20
- Granted: 2020-09-08
- Earliest claimed: 2016-03-04
- Assignees: Micron Technology, Inc.
- Applicants: Micron Technology, Inc.
- Inventors: Kuo-Yao Chou
- Web page: https://patentgrep.com/patent/US10768526B2

## CPC

- G03F 7/0035: {Multiple processes, e.g. applying a further resist layer on an already in a previously step, processed pattern or textured surface}
- G03F 7/16: Coating processes; Apparatus therefor (applying coatings to base materials in general B05; applying photosensitive compositions to base for photographic purposes G03C1/74)
- G03F 7/40: Treatment after imagewise removal, e.g. baking
- H10P 14/69215: {the material being a silicon oxide, e.g. SiO2}
- H10P 50/283: {by chemical means}
- H10P 50/287: {by chemical means}
- H10P 50/71: {using masks for conductive or resistive materials}
- H10P 50/73: {using masks for insulating materials}
- H10P 70/23: {during, before or after processing of insulating materials}
- H10P 76/204: {of organic photoresist masks}
- H10P 76/405: {characterised by their composition, e.g. multilayer masks}
- H10P 76/4085: {characterised by the processes involved to create the masks}
- G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A substrate having a target material layer is provided. A first hard mask layer, a second hard mask layer, and a photoresist layer are formed on the target material layer. The photoresist layer is transferred into first patterns on the second hard mask layer. Regions of the second hard mask layer not protected by the first patterns are etched away, thereby forming second patterns. The first patterns are trimmed to form trimmed features. A conformal spacer material layer is deposited on the trimmed features, the second patterns, and the first hard mask. The spacer material layer is etched to form first spacers on sidewalls of the trimmed features, and second spacers on sidewalls of the second patterns. The trimmed features are removed. Regions of the second patterns not protected by the first spacers are removed, thereby forming patterns with a reduced, fine pitch.

## Claims

### Claim 1

A method of patterning a target material, comprising:
forming a first pattern and a second pattern over a hard mask material on a target material, the first pattern overlying the second pattern;
laterally removing a portion of the first pattern without laterally removing a portion of the second pattern to form trimmed features on the second pattern;
forming first spacers on sidewalls of the trimmed features and second spacers on sidewalls of the second pattern;
removing the trimmed features to expose the second pattern;
removing exposed portions of the second pattern between the first spacers and the second spacers to form a spacer pattern;
removing exposed portions of the hard mask material between the spacer pattern to form a hard mask pattern; and
removing exposed portions of the target material between the hard mask pattern to form a target material pattern.

### Claim 2 (depends on 1)

The method of claim 1, wherein forming a first pattern and a second pattern over a hard mask material comprises forming the first pattern and the second pattern in materials selectively etchable relative to one another.

### Claim 3 (depends on 1)

The method of claim 1, wherein forming a first pattern and a second pattern over a hard mask material comprises forming the first pattern and the second pattern comprising equally-spaced lines.

### Claim 4 (depends on 1)

The method of claim 1, wherein forming a first pattern and a second pattern over a hard mask material comprises forming the first pattern in a photoresist material and forming the second pattern in a spin-on polymer material.

### Claim 5 (depends on 1)

The method of claim 1, wherein forming a first pattern and a second pattern over a hard mask material comprises aligning the first pattern over the second pattern.

### Claim 6 (depends on 1)

The method of claim 1, wherein forming a first pattern and a second pattern over a hard mask material comprises forming the first pattern and the second pattern at a first pitch.

### Claim 7 (depends on 6)

The method of claim 6, wherein removing exposed portions of the target material to form a target material pattern comprises forming the target material pattern at a second pitch, the second pitch equal to about one-quarter of the first pitch.

### Claim 8

A method of patterning a target material, comprising:
forming a first photoresist pattern over a first hard mask material on a target material, the first photoresist pattern comprising a pitch;
forming a second hard mask pattern on the first hard mask material, the second hard mask pattern comprising a second hard mask material;
laterally removing a portion of the first photoresist pattern without laterally removing a portion of the second hard mask pattern to form trimmed photoresist features on the second hard mask pattern;
forming a spacer material over the trimmed photoresist features, the second hard mask pattern, and the first hard mask material;
removing a portion of the spacer material to form first spacers on sidewalls of the trimmed photoresist features and second spacers on sidewalls of the second hard mask pattern;
removing the trimmed photoresist features;
removing the second hard mask material exposed between the first spacers and the second spacers to form a spacer material pattern; and
removing the first hard mask material exposed between the spacer material pattern and the underlying target material to form a target material pattern comprising a pitch about one quarter of the pitch of the first photoresist pattern.

### Claim 9 (depends on 8)

The method of claim 8, wherein forming a first photoresist pattern over a first hard mask material comprises forming the first photoresist pattern over a polysilicon material, a silicon oxide material, a silicon nitride material, a carbon-containing material, or a metal material.

### Claim 10 (depends on 8)

The method of claim 8, wherein forming a first photoresist pattern comprises removing a portion of a first photoresist material overlying the second hard mask material.

### Claim 11 (depends on 8)

The method of claim 8, wherein forming a second hard mask pattern on the first hard mask material comprises using the first photoresist pattern as a mask to form the second hard mask pattern.

### Claim 12 (depends on 8)

The method of claim 8, wherein forming a second hard mask pattern on the first hard mask material comprises forming the second hard mask pattern comprising a second photoresist material.

### Claim 13 (depends on 8)

The method of claim 8, wherein removing the second hard mask material exposed between the first spacers and the second spacers to form a spacer material pattern comprises forming the spacer material pattern comprising the first spacers and the second spacers.

### Claim 14 (depends on 8)

The method of claim 8, wherein removing the first hard mask material exposed between the spacer material pattern and the underlying target material to form a target material pattern comprises forming the target material pattern in a dielectric material, a polysilicon material, or a metal material.

### Claim 15

A method of patterning a target material, comprising:
forming a first pattern over a first hard mask material on a target material;
forming a second pattern over the first hard mask material, the second pattern aligned with the first pattern and comprising a second hard mask material;
laterally removing a portion of the first pattern without laterally removing a portion of the second pattern to form trimmed features on the second pattern;
forming a spacer material over the trimmed features, the second pattern, and the first hard mask material;
removing a portion of the spacer material to form first spacers on sidewalls of the trimmed features and second spacers on sidewalls of the second pattern;
removing the trimmed features;
removing a portion of the second pattern exposed between the first spacers and the second spacers to form a spacer material pattern;
removing the first hard mask material exposed between the spacer material pattern to form a hard mask pattern; and
removing the target material exposed between the hard mask pattern to form a pattern of lines in the target material.

### Claim 16 (depends on 15)

The method of claim 15, wherein forming a first pattern over a first hard mask material on a target material comprises forming a pattern of lines over the first hard mask material.

### Claim 17 (depends on 16)

The method of claim 16, wherein forming a first pattern over a first hard mask material on a target material comprises forming each of the lines of the first pattern at a first pitch.

### Claim 18 (depends on 17)

The method of claim 17, wherein removing the first hard mask material exposed between the spacer material pattern to form a hard mask pattern comprises forming lines of the hard mask pattern at a second pitch equal to about one-quarter of the first pitch.

### Claim 19 (depends on 15)

The method of claim 15, wherein forming a spacer material over the trimmed features, the second pattern, and the first hard mask material comprises conformally forming a silicon oxide material over the trimmed features, the second pattern, and the first hard mask material.

### Claim 20 (depends on 15)

The method of claim 15, wherein removing the target material exposed between the hard mask pattern to form a pattern of lines in the target material comprises forming a pattern of equally-spaced lines in the target material.