KR20150089303A - Method for manufacturing photomask - Google Patents

Abstract

The present invention provides a method for producing a photomask. The method for producing a photomask of the present invention comprises the steps of: providing a transparent substrate having a first region and a second region, provided to an outer region of the first region; sequentially arranging a first film, a light blocking film and a first resist film on the transparent substrate in layers; partially exposing the light blocking film by patterning the first resist film; partially exposing the first film by patterning the light blocking film with etching using the patterned first resist film as a mask; removing the patterned first resist film; forming a second resist film for covering the patterned first film on the transparent substrate; partially removing the second resist film and providing the remaining second resist film to the second region of the transparent substrate; and curing the remaining second resist film.

Description

[0001] METHOD FOR MANUFACTURING PHOTOMASK [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a method of manufacturing a photomask used for manufacturing a semiconductor device.

A lithography process including an exposure process using a photomask is carried out in order to integrate a semiconductor device into a circuit pattern on a wafer. A binary mask and a halftone phase inversion mask are mainly used as a photomask used for manufacturing a semiconductor device. Compared to a binary mask composed of a pattern of a light-shielding layer on a transparent quartz substrate, a halftone phase reversal mask is formed on a transparent substrate with a pattern of a halftone phase reversal film having a low transmittance. These masks are used more and more as the circuit line width of a semiconductor device is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a photomask in which the shielding ability of a blind area is improved in various mask structures.

A photomask manufacturing method for solving the above-mentioned technical problems is presented.

A method of manufacturing a photomask according to the present invention includes: providing a transparent substrate having a first region and a second region provided outside the first region; forming a first film, a light shielding film, and a first resist film on the transparent substrate Patterning the first resist film to partially expose the light shielding film; patterning the light shielding film by etching using the patterned first resist film as a mask to partially expose the first film; Forming a second resist film covering the patterned first film on the transparent substrate; removing a part of the second resist film to form a second resist film on the second region of the transparent substrate; Providing a film, and curing the residual second resist film.

In one embodiment, after removing the first resist film, patterning the first film by etching using the patterned light blocking film as a mask, and removing the light blocking film.

In one embodiment, the first film may comprise a phase reversal film.

In one embodiment, the first resist film includes a positive resist film, and patterning the light shielding film may include exposing a part of the phase reversing film on the first region by removing a part of the light shielding film.

In one embodiment, the first resist film includes a negative resist film, and patterning the light shielding film may include removing a portion of the light shielding film to remove a portion of the phase reversal film on the first region and the phase inversion And exposing the entirety of the film.

In one embodiment, the first film may include a multilayer film in which a high refractive index layer and a low refractive index layer are alternately stacked a plurality of times.

In one embodiment, the first resist film may comprise an extreme ultraviolet photoresist film.

In one embodiment, the first resist film includes a positive resist film, and patterning the light shielding film may include removing a portion of the light shielding film to expose a part of the multilayered film on the first region.

In one embodiment, the first area corresponds to a cell area and the second area corresponds to a blind area.

In one embodiment, the second resist film may comprise any of i-line, g-line, h-line, deep ultraviolet (DUV), and extreme ultraviolet (EUV) photoresist.

The method of manufacturing a photomask according to an exemplary embodiment of the present invention does not remove the resist film in the blind area during the manufacturing process, so that a photomask with improved shielding ability of the blind area can be obtained.

1A to 1G are cross-sectional views illustrating a method of manufacturing a photomask according to an embodiment of the present invention.
2A to 2G are cross-sectional views illustrating a method of manufacturing a photomask according to another embodiment of the present invention.
3A to 3F are cross-sectional views illustrating a method of manufacturing a photomask according to another embodiment of the present invention.

Hereinafter, the method of manufacturing a photomask according to the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages of the present invention and its advantages over the prior art will become apparent from the detailed description and claims that follow. In particular, the invention is well pointed out and distinctly claimed in the claims. The invention, however, may best be understood by reference to the following detailed description when taken in conjunction with the accompanying drawings. Like reference numerals in the drawings denote like elements throughout the various views

Hereinafter, a method of manufacturing a photomask according to an embodiment of the present invention will be described in detail with reference to the drawings.

1A to 1G are cross-sectional views illustrating a method of manufacturing a photomask according to an embodiment of the present invention.

1A, a phase reversal film 20, a light blocking film 30, and a first resist film 40 may be sequentially laminated on a substrate 10.

The substrate 10 may be in the form of a transparent thin film. For example, the substrate 10 may comprise quartz (Qz) or glass.

The phase reversal film 20 can reverse the phase of the transmitted light. The phase reversal film 20 can transmit 100% light, for example. For example, the phase reversal film 20 may comprise a molybdenum compound such as molybdenum silicon (MoSi), molybdenum silicon nitride (MoSiN), or molybdenum silicon oxynitride (MoSiON).

The light blocking film 30 may include a material blocking light. For example, the light blocking film 30 may include chromium (Cr). Etch bias and etch loading can be reduced when the light blocking film 30 is etched as the thickness of the light blocking film 30 is thinner.

The first resist film 40 may be a positive resist film. The first resist film 40 may include any one of i-line (365 nm), h-line (405 nm), and g-line (436 nm) photoresist.

Referring to FIG. 1B, the first resist film 40 may be patterned to expose a part of the light shielding film 30 in the first region A. For example, the first resist film 40 can be patterned by exposure and development using an electron beam (E-beam). The first area A may correspond to a main pattern (e.g., a cell pattern) to be transferred onto the wafer. And the second area B may correspond to the remaining patterns except for the main pattern.

Referring to FIG. 1C, the light blocking film 30 may be patterned by etching using the first resist film 40 as a mask. For example, dry etching or wet etching may be used for patterning the light shielding film 30. The phase reversal film 20 can be partially exposed by etching the light shield film 30. [

Referring to FIG. 1D, after the patterning of the light blocking film 30, the first resist film 40 can be removed by a strip process. The phase reversal film 20 can be patterned by etching using the light shielding film 30 as a mask. For example, dry etch or wet etch may be used to pattern the phase reversal film 20. The substrate 10 may be partly exposed by etching the phase reversal film 20.

Referring to FIG. 1E, the light blocking film 30 may be removed, for example, by a strip process. After the light blocking film 30 is removed, the light blocking film 30 remaining on the phase reversing film 20 can be removed by further performing the cleaning process.

Referring to FIG. 1F, a second resist film 50 may be formed on the substrate 10 to cover the phase reversal film 20. The second resist film 50 may be a positive resist film. The second resist film 50 may include any one of i-line (365 nm), h-line (405 nm), g-line (436 nm), deep ultraviolet (DUV), and extreme ultraviolet . As an example, the second resist film 50 may be an i-line photoresist.

Referring to FIG. 1G, a part of the second resist film 50 of FIG. 1F may be removed. For example, the second resist film 50 on the first region A can be removed by exposure and development using an electron beam. The residual second resist film 50a may be provided on the phase reversal film 20 of the second region B by partially removing the second resist film 50. [

The residual second resist film 50a can be cured. For example, the residual second resist film 50a may be heat-treated or exposed to enhance hardness and adhesion.

The photomask 1 can be manufactured through the series of steps. The photomask 1 may be, for example, a phase reversal photomask. As an example, the remaining second resist film 50a may be an i-line photoresist film having a thickness of about 1500 ANGSTROM. When the remaining second resist film 50a is an i-line photoresist film, the transmittance in the wavelength region of 248 nm or 193 nm is close to zero, so that it can be used as a light shielding film.

2A to 2G are cross-sectional views illustrating a method of manufacturing a photomask according to another embodiment of the present invention.

Referring to FIG. 2A, a phase reversal film 20, a light blocking film 30, and a first resist film 40 may be sequentially formed on a substrate 10.

According to one example, the first resist film 40 may be a negative resist film. The first resist film 40 may include any one of i-line (365 nm), h-line (405 nm), and g-line (436 nm) photoresist.

Referring to FIG. 2B, the first resist film 40 is patterned so that the light blocking film 30 on the second region B is entirely exposed and the light blocking film 30 on the first first region A is partially exposed .

Referring to FIG. 2C, the light blocking film 30 may be patterned by etching using the first resist film 40 as a mask. For example, dry etching or wet etching may be used for patterning the light shielding film 30. The phase reversal film 20 can be partially exposed by etching the light shield film 30. [ After the patterning of the light shielding film 30, the first resist film 40 can be removed by a stripping process.

Referring to FIG. 2D, the phase reversal film 20 may be patterned by etching using the light blocking film 30 as a mask. For example, dry etch or wet etch may be used to pattern the phase reversal film 20. The substrate 10 may be partly exposed by etching the phase reversal film 20.

Referring to FIG. 2E, the light blocking film 30 may be removed. For example, a strip process may be used to remove the light shielding film 30. [ After the light blocking film 30 is removed, the light blocking film 30 remaining on the phase reversing film 20 can be removed by further performing the cleaning process.

Referring to FIG. 2F, a second resist film 50 covering the phase reversal film 20 may be formed on the substrate 10. The second resist film 50 may be a positive resist film or a negative resist film. The second resist film 50 may include any one of i-line (365 nm), h-line (405 nm), g-line (436 nm), deep ultraviolet and extreme ultraviolet photoresist.

Referring to FIG. 2G, a part of the second resist film 50 of FIG. 2F may be removed. The second resist film 50 on the first region A can be removed by exposure and development using an electron beam. The residual second resist film 50a may be provided on the phase reversal film 20 on the second region B by removing part of the second resist film 50. [

The residual second resist film 50a can be cured. For example, the residual second resist film 50a may be heat-treated or exposed to enhance hardness and adhesion. As an example, the remaining second resist film 50a may be an i-line photoresist film.

The photomask 2 can be manufactured through the series of steps. The photomask 2 may be a phase reversal photomask utilizing the remaining second resist film 50a as a light shielding film.

According to the present embodiment, the photomask 2 can be realized in which uniform exposure is prevented by uniformly deteriorating the electron charging effect, shortening the exposure time, and uniform deterioration due to the photoresist loading, have.

3A to 3F are cross-sectional views illustrating a method of manufacturing a photomask according to another embodiment of the present invention.

3A, a multilayer thin film 25, a light shielding film 30, and a first resist film 40 may be laminated in this order on a substrate 10.

The multilayered film 25 may include a material having a high reflectance for extreme ultraviolet rays. The multilayer thin film (25) can alternately laminate the high refractive index layer and the low refractive index layer a plurality of times. For example, the high refractive index layer may comprise molybdenum (Mo) and the low refractive index layer may comprise silicon (Si). The multilayered film 25 is not limited to this and may be any of ruthenium / silicon, molybdenum / beryllium (Be), molybdenum compound / silicon compound, silicon / molybdenum / ruthenium, silicon / molybdenum / ruthenium / molybdenum, / Ruthenium. ≪ / RTI > The thickness of each layer of the multilayered film (25) may be, for example, 2.3 nm, and the number of repeating units of each layer may be 30 to 60. [ However, the thickness of each layer and the number of repeating units of each layer may differ from the values exemplified by the wavelength of the extreme ultraviolet ray used and the like.

The first resist film 40 may be a positive resist film. The first resist film 40 may be, for example, an extreme ultraviolet photoresist film.

Referring to FIG. 3B, the first resist film 40 may be patterned to expose a part of the light blocking film 30 in the first region A. The first resist film 40 can be patterned by an exposure and development process using an electron beam.

Referring to FIG. 3C, the light blocking film 30 may be patterned by etching using the first resist film 40 as a mask. For example, dry etching or wet etching may be used for patterning the light shielding film 30. A part of the multilayer thin film 25 can be exposed by etching the light shielding film 30.

Referring to FIG. 3D, the first resist film 40 can be removed by a strip process. According to this embodiment, the light blocking film 30 can be left without being removed.

Referring to FIG. 3E, the second resist film 50 may be formed on the light blocking film 30. FIG. The second resist film 50 may be a positive resist film or a negative resist film. The second resist film 50 may comprise any one of i-line (365 nm), h-line (405 nm), and g-line (436 nm), extreme ultraviolet, and far ultraviolet photoresist.

Referring to FIG. 3F, a part of the second resist film 50 may be removed. For example, the second resist film 50 on the first region A can be removed by exposure and development using an electron beam. The remaining second resist film 50a may be provided on the light shielding film 30 on the second region B by removing a part of the second resist film 50. [

The residual second resist film 50a can be cured. For example, the residual second resist film 50a may be heat-treated or exposed to enhance hardness and adhesion.

A photomask 3 such as an extreme ultraviolet photomask can be manufactured through the series of processes described above. According to this embodiment, it is possible to manufacture the photomask 3 in which the broadband wavelength is not reflected without etching the multilayer thin film 25 of the second region B. [ Therefore, in manufacturing the photomask 3 according to the embodiment of the present invention, the number of processes may be reduced and distortion of a critical dimension (CD) may not occur.

It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit of the invention. The appended claims should be construed to include other embodiments.

Claims (10)

Providing a transparent substrate having a first region and a second region provided at an outer portion of the first region;
Sequentially stacking a first film, a light shielding film and a first resist film on the transparent substrate;
Patterning the first resist film to partially expose the light shielding film;
Patterning the light shielding film by etching using the patterned first resist film as a mask to partially expose the first film;
Removing the patterned first resist film;
Forming a second resist film covering the patterned first film on the transparent substrate;
Removing a portion of the second resist film on the first region to provide a remaining second resist film on the second region; And
Curing the residual second resist film;
≪ / RTI > The method according to claim 1,
After removing the first resist film,
Patterning the first film by etching using the patterned light blocking film as a mask; And
Removing the patterned light blocking film;
≪ / RTI > 3. The method of claim 2,
Wherein the first film comprises a phase reversal film. The method of claim 3,
Wherein the first resist film includes a positive resist film,
Patterning the light-blocking film may include:
And removing a part of the light shielding film to expose a part of the phase reversal film on the first region. The method of claim 3,
Wherein the first resist film comprises a negative resist film,
Patterning the light-blocking film may include:
Removing a part of the light shielding film to expose a part of the phase reversal film on the first region and all of the phase reversal film on the second region. The method according to claim 1,
Wherein the first film comprises a multilayer thin film in which a high refractive index layer and a low refractive index layer are alternately laminated a plurality of times. The method according to claim 6,
Wherein the first resist film comprises an extreme ultraviolet photoresist film. The method according to claim 6,
Wherein the first resist film includes a positive resist film,
Patterning the light-blocking film may include:
And removing a part of the light shielding film to expose a part of the multilayered film on the first area. The method according to claim 1,
Wherein the first region corresponds to a cell region and the second region corresponds to a blind region. The method according to claim 1,
Wherein the second resist film comprises any one of an i-line, a g-line, an h-line, a deep ultraviolet (DUV), and an extreme ultraviolet (EUV) photoresist.

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