# US 7,745,339 B2 · Method for forming fine pattern of semiconductor device

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- Number: US 7,745,339 B2
- Document ID: US7745339B2
- Status: Granted
- Kind: B2
- Application number: 11/672,676
- Filed: 2007-02-08
- Published: 2007-08-30
- Granted: 2010-06-29
- Earliest claimed: 2006-02-24
- Assignees: Hynix Semiconductor Inc.
- Inventors: Jae Chang Jung
- Web page: https://patentgrep.com/patent/US7745339B2

## CPC

- H10W 20/031: {of conductive parts of the interconnections}
- H10P 50/266: {by vapour etching only}
- H10P 50/287: {by chemical means}
- H10P 50/71: {using masks for conductive or resistive materials}
- H10P 76/4085: {characterised by the processes involved to create the masks}
- H10P 76/4088: {Processes for improving the resolution of the masks}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A method for forming a fine pattern of a semiconductor device comprises the steps of: forming a first hard mask pattern having a width of W1 and a thickness of T1 over an underlying layer formed over a semiconductor substrate; forming a second hard mask film with a planar type over the resulting structure and planarizing the second hard mask s to expose the first hard mask pattern; removing the first hard mask pattern by a thickness T2 from the top surface (0<T2<T1); performing a trimming process on the second hard mask film to form a second hard mask pattern having a slope side wall; performing a second trimming process on the second hard mask pattern to separate the second hard mask pattern from the first hard mask pattern and form a third hard mask pattern having a width of W2; and patterning the underlying layer using the first hard mask pattern and the third hard mask pattern as etching masks.

## Claims

### Claim 1

A method for forming a pattern of a semiconductor device, the method comprising:
forming a first hard mask pattern having a first width and a first thickness over an underlying layer formed over a semiconductor substrate;
forming a second hard mask film over the first mask pattern;
removing the second hard mask film at least until the first hard mask pattern is exposed;
removing an upper portion of the exposed first hard mask pattern, so that an upper surface of the resulting first hard mask pattern is provided to be lower than an upper surface of the second hard mask film;
performing a first trimming process on the second hard mask film to form a second hard mask pattern having a sloped sidewall;
performing a second trimming process on the second hard mask pattern to convert the second hard mask pattern into a third hard mask pattern having a second width, the first and third hard mask patterns together exposing portions of the underlying layer; and
patterning the underlying layer using the first and third hard mask patterns as etching masks.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the patterned underlying is a word line, a bit line, or a metal line.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the first hard mask film includes one selected from the group consisting of polysilicon, an oxide film, a metal and combinations thereof.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the first width is a limit-resolution-size patternable by a lithography equipment used to form the pattern.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the first width of the first hard mask pattern is substantially the same as the second width of the third hard mask pattern.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the second hard mask film is formed with a material having an etch selectivity that is different than the etch selectivity of the first mask film.

### Claim 7 (depends on 6)

The method according to claim 6, wherein the second mask film is an organic film or an inorganic film.

### Claim 8 (depends on 7)

The method according to claim 7, wherein the organic film includes a photoresist film or an anti-reflection film, each of which is formed by a spin-coating process.

### Claim 9 (depends on 8)

The method according to claim 8, wherein the organic film is a photoresist film, wherein a base resin of the photoresist film includes one selected from the group consisting of a polyvinylphenol type, a polyhydroxystyrene type, a polynorbornene type, a polyadamantyl type, a polyimide type, a polyacrylate type, a polymethacrylate type, a polyfluorine type and combinations thereof.

### Claim 10 (depends on 8)

The method according to claim 8, wherein the organic film is an anti-reflection film, wherein the anti-reflection film is formed of a resin selected from the group consisting of phenylamine resin, melamine derivative resin, alkali soluble resin, acrylate resin, epoxy resin and combinations thereof.

### Claim 11 (depends on 7)

The method according to claim 7, wherein the inorganic film includes a nitride film or a polysilicon layer.

### Claim 12 (depends on 1)

The method according to claim 1, wherein the removing-the-first-mask-pattern step is performed with an etch gas selected from the group consisting of CF4, Cl2, HBr and combinations thereof.

### Claim 13 (depends on 1)

The method according to claim 1, wherein the first trimming process is performed under such a condition that the etch selectivity of second mask pattern: first mask pattern=9˜10:1, and
wherein the first trimming process is performed using an etching gas selected from the group consisting of CF4, N2, O2, Ar, H and combinations thereof.

### Claim 14 (depends on 13)

The method according to claim 13, wherein the first trimming process is performed using an etching gas including O2:CF4:Ar=1:7˜10:25˜45 as components.

### Claim 15 (depends on 1)

The method according to claim 1, wherein the second trimming process is performed under such a condition that the etch selectivity of second mask pattern: first mask pattern=9˜10:1, and
wherein the second trimming process is performed using an etching gas selected from the group consisting of CF4, N2, O2, Ar, H and combinations thereof.

### Claim 16 (depends on 15)

The method according to claim 15, wherein the second trimming process is performed using an etching gas including O2:CF4:Ar=1:40˜80:25˜50 as main components.

### Claim 17

A method for forming a pattern for a substrate, the method comprising:
forming a first hard mask pattern having first and second structures over an underlying layer, the first and second structures defining a first space and exposing a portion of the underlying layer;
forming a second hard mask film over the first hard mask pattern and within the first space, the underlying layer being substantially covered by the first hard mask pattern and the second mask film;
removing the second hard mask film to provide a third structure defined within the first space, the first and second structures of the first hard mask pattern being exposed;
removing an upper portion of the exposed first hard mask pattern such that an upper surface of the first hard mask pattern is lower than an upper surface of the second hard mask pattern;
etching the third structure to define a second space between the first structure and the third structure and a third space between the second structure and the third structure, the second space and the third space each exposing a portion of the underlying layer; and
etching the portions of the underlying layer exposed by the second space and third space.

### Claim 18 (depends on 17)

The method of claim 17, further comprising:
removing upper portions of the exposed first and second structures until the first and second structures have a lower height than the third structure,
wherein the third structure is etched until the third structure is provided with substantially the same thickness as the first structure,
wherein the underlying layer is provided over the substrate.

### Claim 19 (depends on 17)

The method of claim 17, wherein the underlying layer is part of the substrate.

### Claim 20

A method for forming a pattern for a substrate, the method comprising:
forming a first hard mask pattern having first and second structures over an underlying layer, the first and second structures defining a first space and exposing a portion of the underlying layer;
forming a second hard mask film over the first hard mask pattern and within the first space, the underlying layer being substantially covered by the first hard mask pattern and the second mask film;
removing the second hard mask film to provide a third structure defined within the first space, the first and second structures of the first hard mask pattern being exposed;
removing an upper portion of the exposed first hard mask pattern such that an upper surface of the first hard mask pattern is lower than an upper surface of the second hard mask pattern;
etching the third structure until the first, second, and third structures define a given pattern that exposes portions of the underlying layer; and
etching the underlying layer to transfer the given pattern to the underlying layer.

### Claim 21 (depends on 20)

The method of claim 20, further comprising:
removing upper portions of the exposed first and second structures until the first and second structures have a lower height than the third structure,
wherein the third structure is etched until the third structure is provided with substantially the same thickness as the first structure,
wherein the underlying layer is provided over the substrate.