KR20180101119A - Phase Shift Blankmask and Photomask - Google Patents

Abstract

The phase reversal film according to the present invention is formed of films of mutually different compositions that can be etched into the same etching solution and is formed in the form of a multilayer film or a continuous film of at least two or more layers in which films of different compositions are laminated one or more times. Accordingly, the present invention can reduce the thickness of the phase reversal film and can steeply form the edge section slope so that the boundary of the phase halftone pattern becomes clear at the time of patterning the phase reversal film, so that the transmittance of the phase halftone pattern, It is possible to provide a phase inversion blank mask and a photomask which can improve the pattern precision of the phase reversal film pattern and the transferred body.

Description

Phase Inversion Blank Mask and Photomask [

The present invention relates to a phase inversion blank mask and a photomask, and more particularly to a phase inversion blank mask having a surface reflectance of 35% or less at a wavelength of ihg line (365 nm, 405 nm, 436 nm) Phase inversion blank mask and a method of manufacturing the photomask.

In a lithography process for manufacturing a flat panel display (FPD) device or a semiconductor integrated circuit device including a TFT-LCD, an OLED, and a PDP, a pattern using a photomask commonly manufactured from a blank mask Is transferred.

The blank mask is formed by forming a thin film containing a metal material on the main surface of a transparent substrate made of synthetic quartz glass or the like, and a resist film is formed on the thin film, and the photomask has a form in which the thin film is patterned from such blank mask. Here, the thin film may be classified into a light-shielding film, an antireflection film, a phase reversal film, a semitransparent film, a hard film, etc. depending on optical characteristics, and a thin film containing two or more of these thin films may be used in combination.

In recent years, as the market demand for FPD products has become more sophisticated and sophisticated, the application range of FPD products has been expanded, and it is required to develop excellent manufacturing process technology. That is, as with semiconductor devices having high integration, FPD devices are also required to have high pattern resolution and high definition technology in order to increase the degree of integration.

As a method for improving the precision of a photomask for FPD device fabrication, it has been found that even in the equipotential exposure apparatus, the phase is approximately 180 (nm) for the exposure light of a complex wavelength including i-line (365 nm), h- Phase inversion blank mask and photomask for an FPD having an inverted phase reversal film have been developed. The phase reversal film is a monolayer thin film formed of a molybdenum silicide (MoSi) compound or a chromium (Cr) compound. A thin film formed on a large area substrate is formed in the form of a pattern using wet etching.

The phase reversal film in the form of a single layer composed of the molybdenum silicide (MoSi) compound or the chromium (Cr) compound has an isotropic etching property in wet etching suitable for a large area, and accordingly, the etching section of the edge portion of the phase reversal film pattern It is formed into a shape having a gentle slope. The inclination of the edge portion of the pattern generates a difference between the transmittance and the phase inversion amount at the pattern edge portion and other portions, thereby affecting the uniformity of the line width of the phase reversal film pattern. The boundary of the phase reversal film is unclear due to the inclination of the phase reversal film at the edge portion of the pattern, and it is difficult to form a fine pattern.

On the other hand, when the reflectance of the phase reversal film is high, it is difficult to form a fine pattern due to the interference effect between the reflected light on the surface of the thin film and the exposure light during the printing process, and low reflectance characteristics for low light are required.

An object of the present invention is to provide a phase inversion blank mask and a photomask excellent in the Sidewall Angle of the phase reversal film pattern. Thus, the transmittance and phase uniformity in the pattern edge region can be improved, and the accuracy and uniformity of the pattern line width of the phase reversal film pattern and the transferred body can be finally improved.

It is still another object of the present invention to provide a phase inversion blank mask and a photomask capable of improving the fine pattern accuracy of a transferred body by reducing the reflectance of the surface of the phase inversion film and preventing the generation of interference waves due to the reflected light on the surface.

The present invention relates to a phase inversion blank mask having a phase reversal film on a transparent substrate, wherein the phase reversal film is composed of at least two or more multilayer films, and is composed of oxygen (O), nitrogen (N), carbon (C) B), and hydrogen (H). ≪ IMAGE >

The metal component of the metal silicide compound may be at least one selected from the group consisting of Al, Co, W, Mo, Cr, V, Pd, Ti, (Pt), Mn, Fe, Ni, Cd, Zr, Mg, Li, Se, (Y), S, In, Sn, Boron, Be, Sodium, Ta, Hafnium, Niobium, , And the like.

In particular, the phase reversal film may be composed of at least one selected from MoSiO, MoSiN, MoSiC, MoSiON, MoSiCN, MoSiCO, and MoSiCON as the silicon compound containing molybdenum (Mo).

Wherein the metal silicide compound film contains 2 to 30 at% of molybdenum (Mo), 20 to 70 at% of silicon (Si), 5 to 50 at% of nitrogen (N), 0 to 30 at% of oxygen (O) , And the carbon (C) has a content of 0 to 30 at%.

The phase reversal films may have the same composition or the light elements may have different compositions. For example, in the case of a phase reversal film composed of two layers, MoSiN and MoSiN may be composed of the same composition, and MoSiN and MoSiON may be composed of different compositions.

Each of the films constituting the phase reversal film may be formed in the form of a single film having the same composition and composition ratio or a continuous film having a varying composition or composition ratio.

The uppermost film among the films constituting the phase reversal film may have a higher nitrogen (N) content than at least any of the lower films, or the layer adjacent to the transparent substrate may have a lower content of nitrogen (N) .

The uppermost film among the films constituting the phase reversal film may have a low oxygen (O) content with respect to at least any of the lower films, or the layer adjacent to the transparent substrate may have a higher content of oxygen (O) .

When the uppermost film among the films constituting the phase reversal film contains oxygen, the thickness is controlled to 30 nm or less and the content of oxygen is controlled to 30 at% or less.

The uppermost film among the films constituting the phase reversal film may have a higher carbon (C) content than at least any of the lower films, or the layer adjacent to the transparent substrate may be configured to have a lower carbon (C) content than either of the upper films have.

The total thickness of the phase reversal film is 500 ANGSTROM to 1,500 ANGSTROM, and the films constituting the phase reversal film have a thickness of 50 ANGSTROM to 1,450 ANGSTROM.

The films constituting the phase reversal film are etchable in the same etching solution.

The etching solution of the phase reversal film is preferably an etching solution containing ammonia hydrogendifluoride [(NH4) HF2], hydrogen peroxide (H2O2) and DI-water as main components.

It is preferable that the solution of Ammonium hydrogendifluoride [(NH4) HF2] which is the main component of the etching solution of the phase reversal film contains 10% or less, preferably 5% or less.

It is preferable that the phase reversal film has a reflectance of 35% or less with respect to exposure light of a composite wavelength including i-line (365 nm), h-line (405 nm), and g-line (436 nm).

It is preferable that the phase reversal film has a lowest reflectance at a wavelength of 400 nm to 900 nm or less.

The phase reversal film may have a transmittance of 1% to 40% and a transmittance deviation of 10% or less with respect to exposure light of a composite wavelength including i-line, h-line and g-line.

The phase reversal film may have a phase inversion amount of 160 ° to 200 ° with respect to exposure light of a composite wavelength including an i-line, an h-line, and a g-line, and the phase amount deviation may be 40 ° or less.

The phase inversion blank mask of the present invention may further include one of a light shielding film or a metal film of one or more layers on or under the phase reversal film. At this time, the metal film may be one of a transflective film, an etching stopper film, and an etching mask film.

The phase inversion blank mask of the present invention may further include one of a light shielding film or a metal film of one or more layers on or under the phase reversal film. At this time, the metal film may be one of a transflective film, an etching stopper film, and an etching mask film.

The light shielding film and the metal film may be formed of at least one of chromium (Cr), aluminum (Al), cobalt (Co), tungsten (W), molybdenum (Mo), vanadium (V), palladium (Pd) (Pt), Mn, Fe, Ni, Cd, Zr, Mg, Li, Selenium, Cu, (Y), sulfur (S), indium (In), tin (Sn), boron (B), beryllium (Be), sodium (Na), tantalum (Ta), hafnium (Hf), niobium (Si), or may further include one or more of nitrogen (N), oxygen (O), and carbon (C) in the metal materials.

According to another aspect of the present invention, there is provided a phase inversion photomask fabricated using a phase inversion blank mask having the above-described configuration, comprising: a phase reversal film pattern made of at least two or more multi- Wherein each film constituting the phase reversal film pattern is made of a metal silicide compound containing at least one of oxygen (O), nitrogen (N) and carbon (C), and i-line (365 nm), h There is provided a phase inversion photomask having a reflectance of 35% or less with respect to exposure light of a composite wavelength including a line (405 nm) and a g line (436 nm).

The phase reversal film pattern preferably has a horizontal distance between an upper edge and a lower edge of 100 nm or less.

It is preferable that the phase reversal film pattern has an angle (?) Of 70 ° to 110 ° in the cross section of the upper surface and the pattern edge portion.

According to the present invention, the phase reversal film is formed in a multi-layered structure of two or more layers, and each of the films can be formed as a single film or a continuous film. In addition, when the phase reversal film is formed, the shape of the pattern and the surface reflectance can be controlled by controlling the content of oxygen, nitrogen, and carbon contained in each layer.

This allows Sidewall Angle to manufacture excellent phase inversion blank masks and photomasks. Thus, the transmittance and phase uniformity in the pattern edge region can be improved, and the accuracy and uniformity of the pattern line width of the phase reversal film pattern and the transferred body can be finally improved.

Further, through the present invention, it is possible to manufacture a phase inversion blank mask and a photomask capable of improving the fine pattern accuracy of the transferred body by reducing the reflectance on the surface of the phase reversal film and preventing the generation of interference waves due to the surface reflected light.

1 is a cross-sectional view showing a phase inversion blank mask according to a first embodiment of the present invention;
2 is a cross-sectional view showing a phase reversal film in the blank mask of FIG. 1;
FIGS. 3A to 3F are cross-sectional views illustrating a method of manufacturing a phase-reversal photomask and a phase-reversal photomask according to a first embodiment of the present invention;
4 is a cross-sectional view showing a phase inversion photomask according to a second embodiment of the present invention;
5 is a sectional view showing a phase inversion blank mask according to a third embodiment of the present invention.
6 is a cross-sectional view showing an interface of a phase reversal film according to the present invention.
7 is a graph showing reflectance and transmittance according to an embodiment of the present invention.
8 is a cross-sectional view of a photomask pattern according to an embodiment of the present invention.
9 is a graph showing reflectance and transmittance according to Comparative Example 1. Fig.
10 is a photograph showing a cross section of a photomask pattern according to Comparative Example 1. Fig.
11 is a graph showing reflectance and transmittance according to Comparative Example 2. Fig.
12 is a photograph showing a cross section of the photomask pattern according to Comparative Example 2. Fig.

Hereinafter, the present invention will be described in detail with reference to the drawings, but it should be understood that the present invention is not limited to these embodiments. For example, And is not intended to limit the scope of the invention. Therefore, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Accordingly, the true scope of protection of the present invention should be determined by the technical matters of the claims.

Hereinafter, the phase inversion blank mask and the photomask implemented in the embodiments of the present invention will be described in detail. The phase inversion blank mask and the photomask implemented in the embodiments of the present invention can be applied to FPD devices including semiconductors for liquid crystal displays (LCDs), plasma display panels (PDPs), organic light emitting diodes A phase inversion blank mask and a photomask. The exposure light has wavelengths of i-line (365 nm), h-line (405 nm), g-line (436 nm), KrF (248 nm) and ArF 436nm). ≪ / RTI >

FIG. 1 is a cross-sectional view illustrating a phase inversion blank mask according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a phase inversion film according to an embodiment of the present invention.

1, a phase inversion blank mask 100 according to the present invention has a structure in which a phase reversal film 104, a light shielding film 110, and a resist film 114 are sequentially laminated on a transparent substrate 102 .

The transparent substrate 102 may be, for example, a quadrangular transparent substrate having a length of 300 mm or more on one side, and may be a synthetic quartz glass, a soda lime glass substrate, a non-alkali glass substrate, a low thermal expansion glass substrate, or the like.

Referring to FIG. 2, the phase reversal film 104 has a structure in which at least two thin films 104a to 104n are stacked, preferably two to ten layers, more preferably two layers To 8 layers.

Each of the thin films 104a to 104n forming the phase reversal film 104 is formed of a metal silicide or a metal silicide and a metal silicide such as oxygen (O), nitrogen (N), carbon (C), boron (B) H). ≪ / RTI >

The metal component of the metal silicide and the compound thereof is selected from the group consisting of Al, Co, Pt, manganese, iron, nickel, cadmium, zirconium, magnesium, lithium, selenium, copper, yttrium, Y), sulfur (S), indium (In), tin (Sn), boron (B), beryllium (Be), sodium (Na), tantalum (Ta), hafnium (Hf), and niobium And at least one of them.

Particularly, the thin films 104a to 104n forming the phase reversal film 104 are formed of molybdenum silicide (MoSi) containing molybdenum (Mo) and MoSiO, MoSiN, MoSiC, MoSiON, MoSiCN, MoSiCO, and MoSiCON.

The molybdenum silicide (MoSi) compound film has a molybdenum (Mo) content of 2 at% to 30 at%, a silicon (Si) content of 20 at% to 70 at%, a nitrogen (N) content of 5 at% to 50 at% 0 to 30 at%, and carbon (C) in an amount of 0 to 30 at%.

The thin films 104a to 104n forming the phase reversal film 104 may have the same composition or the light elements may have different compositions. For example, in the case of a phase reversal film composed of two layers, MoSiN and MoSiN may be composed of the same composition, and MoSiN and MoSiON may be composed of different compositions. Further, when the thin films have the same composition, the constituent materials can be formed to have different composition ratios.

The thin films 104a to 104n forming the phase reversal film 104 can be formed in the form of a single film having the same composition and composition ratio, or a continuous film having a varying composition or composition ratio. Here, the continuous film refers to a film formed by changing process parameters such as reactive gas, power, pressure, and the like during the sputtering process in a state in which the plasma is turned on.

Since the thin films 104a to 104n forming the phase reversal film have different etching rates and surface reflectivities for the same etching solution depending on the parameters such as composition, composition ratio, and thickness, the pattern formation of the phase reversal film The edge section of the pattern is formed so as to be steeply inclined, and is appropriately arranged so as to control the reflectance.

First, it is preferable to adjust the content of the light element material by adjusting the etching speed of the phase reversal film 104 to make the inclination of the section steep. When the content of nitrogen (N) or carbon (C) in the light element is increased in detail, the etching rate can be slowed and the etching rate can be increased in the case of increasing the content of oxygen (O).

In detail, when the etching rate is controlled by changing the contents of nitrogen (N) and carbon (C), the phase reversal thin films 104a to 104n are formed such that the film of the uppermost layer among the films is at least (N) or carbon (C) content, or the film adjacent to the transparent substrate is lower than the content of nitrogen (N) or carbon (C) contained in any one of the upper films. For example, the content of nitrogen (N) or carbon (C) can be made relatively small in the thin film from the uppermost film to the lower film, thereby improving the sidewall angle of the pattern.

Unlike nitrogen (N) or carbon (C) in the case of oxygen (O), the film of the uppermost layer of each film has a low oxygen (O) content relative to at least any of the films, The content of oxygen (O) contained in the film of the first layer is higher than that of oxygen. For example, the content of oxygen (O) in the thin film increases from the top to the bottom, and the Sidewall angle can be made excellent. On the other hand, in the case of the reflectance, the higher the oxygen content of the thin film of the uppermost layer, the more the effect of reducing the reflectance can be obtained. On the other hand, the reflectance of the phase reversal film 104 can be adjusted by changing the content of each of nitrogen (N) and oxygen (O), or both, contained in the thin films 104a to 104n , Nitrogen (N), and oxygen (O) can be increased to lower the reflectance. However, in the case of oxygen (O), it acts as a factor to increase the etch rate, which acts as a factor to increase the etch rate in comparison with the reflectance reduction, which may cause the sidewall angle to deteriorate. Accordingly, the content of oxygen contained in the thin films 104a to 104n included in the phase reversal film is controlled to 30at% or less, preferably 20at% or less, and the thickness thereof is preferably controlled to 30nm or less Do.

Accordingly, the thin films 106a, ..., 106n according to the present invention can be formed of the above-mentioned nitrogen (N), carbon (C), oxygen (O) It is preferable not to arrange them in the thin films 106a, ..., 106n so as to be limited to the etching characteristics, but to arrange them in consideration of all the optical characteristics such as the reflectance. That is to say, the etching rate and the reflectance ratio depend on the kind of the film forming gases for forming the thin films 106a, ..., 106n, the content of nitrogen (N), carbon (C), and oxygen (O) The thin films 106a and 106b are arranged such that the thin film disposed at a specific portion is structured such that the etching rate is slower or faster than that of the thin film disposed at the upper portion or the lower portion thereof, ..., 106n may be stacked in various forms to optimize the etch cross section and reflectivity. This is because a film containing nitrogen (N), carbon (C), and oxygen (O), which are similar to or different from each other in the film formation gas during formation of the films 106a, The etching rate and the reflectance of the thin films 106a, ..., 106n can be adjusted to an optimum state by properly controlling the amount of gas to be injected.

The total thickness of the phase reversal film has a thickness of 500 ANGSTROM to 1,500 ANGSTROM, preferably 900 ANGSTROM to 1,300 ANGSTROM. The thin films 104a to 104n constituting the phase reversal film 104 have a thickness of 50 Å to 1,450 Å in consideration of adhesion with the films disposed on the upper and lower sides, etching properties, and the like.

The films constituting the phase reversal film are etchable in the same etching solution.

The etching solution of the phase reversal film is preferably an etching solution containing Ammonium hydrogendifluoride [(NH ₄ ) HF ₂ ], hydrogen peroxide (H ₂ O ₂ ) and DI-water as main components. Ammonium hydrogendifluoride [(NH ₄ ) HF ₂ ] among the main components of the etching solution is preferably contained in an amount of 10 vol% or less, preferably 5 vol% or less. This is because, when the phase reversal film is etched, the surface of the substrate may be damaged if the content of the solution of Ammonium hydrogendifluoride [(NH ₄ ) HF ₂ ] is 10 vol% or more.

The phase reversal film 104 has a reflectance of 35% or less in exposure light of a composite wavelength including i-line (365 nm), h-line (405 nm), and g-line (436 nm). In addition, the phase reversal film 104 should be controlled so that the lowest reflectance is located at one of the wavelength ranges of 400 nm to 900 nm, preferably in the wavelength range of 500 nm to 800 nm.

The phase reversal film 104 has a transmittance of 1% to 40% with respect to the exposure light and preferably has a transmittance of 5% to 20% and has a transmittance deviation of 10% or less with respect to each exposure light (ihg line) . Here, the phase reversal amount, the transmittance, and the reflectance deviation refer to the difference between the maximum value and the minimum value of the transmittance values according to the exposure light of i-line, h-line, and g-line.

The phase reversal film has a phase inversion amount of 160 to 200 relative to exposure light of a composite wavelength including i-line, h-line and g-line, the phase amount deviation has a phase inversion amount deviation of 40 or less, , And has a phase inversion deviation of 30 degrees or less.

The phase inversion blank mask of the present invention may further include one of a light shielding film or a metal film of one or more layers on or under the phase reversal film. In detail, the metal film may be one of a transflective film, an etch stop film, and an etch mask.

When the phase reversal film includes one or more metal films on the upper or lower portion thereof, the phase reversal film may have a phase inversion amount of 160 to 200 degrees with respect to the ihg line, or a phase inversion amount of 110 to 150 degrees As shown in Fig. For example, when the metal film is a transflective film having a predetermined transmittance, the phase reversal film formed under the phase reversal film preferably has a phase reversal amount of 110 ° to 150 °. On the other hand, when the phase reversal film is formed on top of the phase reversal film, for example, when forming the phase reversal film pattern, it is preferable that the phase reversal film has a phase reversal amount of 160to 200to the i-h-g line. On the other hand, in the case of the transmittance of the phase reversal film, the transmissivity can be controlled within the range of 1 to 40% according to the semi-permeable film lamination.

First, the light shielding film 110 disposed on the top of the phase reversal film 104 may be used as an etching mask for patterning the phase reversal film 104 in the form of a pattern in manufacturing a photomask.

The light shielding film and the metal film may be formed of at least one of chromium (Cr), aluminum (Al), cobalt (Co), tungsten (W), molybdenum (Mo), vanadium (V), palladium (Pd) (Pt), Mn, Fe, Ni, Cd, Zr, Mg, Li, Selenium, Cu, (Y), sulfur (S), indium (In), tin (Sn), boron (B), beryllium (Be), sodium (Na), tantalum (Ta), hafnium (Hf), niobium (Si), or may further include one or more of nitrogen (N), oxygen (O), and carbon (C) in the metal materials.

The light shielding film and the metal film are preferably made of molybdenum chromium (MoCr), chromium (Cr) or a compound containing at least one of oxygen (O), nitrogen (N), and carbon (C) MoCrO, MoCrN, MoCrC, MoCrCN, MoCrCO, MoCrCON, CrO, CrN, CrC, CrCN, CrCO and CrCON films.

The light shielding film 110 is preferably formed in the form of a multilayer or continuous film of two or more layers including a light shielding film 106 and an antireflection film 108. When the light shielding film 106 has an antireflection function, May not be formed.

It is preferable that the light shielding film 110 is formed in the form of a multilayer film or a continuous film of two or more layers which are made of a material that can be etched together with the same etching solution and have different compositions or composition ratios and are stacked one or more times. At this time, the thin films constituting the light shielding film 110 can be appropriately disposed in consideration of the above variables because the etching rate is different for the same etching material depending on parameters such as composition, composition ratio, thickness, and the like.

The light shielding film formed by the light shielding film 110 may be removed after the formation of the pattern of the phase inverting film 104 disposed at the bottom or the phase reversing film 104 required to define a blind area at the edge of the substrate. And may remain on a portion of the pattern.

The light shielding film 110 has an optical density of 2 to 6 for the exposure light in the laminated structure with the pattern of the phase reversal film 104 or a pattern structure including the metal film and has a thickness of 500 Å to 2,000 Å . Further, the light shielding film 110 has a reflectance of 30% or less with respect to the exposure light, preferably 20% or less, more preferably 15% or less.

When the metal film is a semi-transparent film, the thickness of the metal film is 50 Å to 500 Å, the transmittance is 10% to 50% with respect to exposure light, and the amount of phase has 10 to 50 degrees.

As described above, the present invention can improve the sidewall angle of the phase reversal film pattern by forming the phase reversal film using a molybdenum silicide (MoSi) or a compound thereof to form a multilayer film having mutually different etching rates. Also, the content of oxygen and nitrogen in the surface layer can be controlled to reduce the reflectance.

Accordingly, the CD (critical dimension) precision and uniformity of the phase reversal film pattern can be improved, and a fine phase reversal film pattern of 2 탆 or less, preferably 1.8 탆 or less, more preferably 1.5 탆 or less can be realized .

In addition, it is possible to manufacture a phase inversion blank mask having a gray tone function by disposing a semi-transparent film on the phase reversal film or below the phase inversion blank mask.

3A to 3F are cross-sectional views illustrating a method for manufacturing a phase-inverted photomask and a phase-inverted photomask according to a first embodiment of the present invention.

3A, a phase inversion photomask according to the present invention includes a phase reversal film 104, a light shielding film 110, and a resist film 114 sequentially stacked on a transparent substrate 102 to form a phase inversion blank mask 100).

The phase reversal film 104 and the light shielding film 110 may be formed by a reactive magnetron sputtering method.

At this time, it is preferable that the phase reversal film 104 and the light shielding film 110 use at least one reactive gas of NO, N ₂ O, NO ₂ , N ₂ , O ₂ , CO ₂ , CO and CH ₄ together , A gas capable of providing oxygen (O), nitrogen (N), and carbon (C) in addition to the reactive gas can be freely formed.

When each thin film constituting the phase reversal film 104 is composed of molybdenum silicide (MoSi) or a compound thereof, the phase reversal film 104 is a single target of molybdenum silicide (MoSi) or a single target of molybdenum silicide Mo) and silicon (Si), for example, by sputtering. The molybdenum silicide (MoSi) single target has a composition ratio of Mo: Si = 2 at% to 30 at%: 70 at% to 98 at%, for example, Mo: Si = 10 at% A target having various composition ratios such as Mo: Si: 20at%: 80at%, Mo: Si = 30at%: 70at% Can be freely adjusted in accordance with the conditions of FIG.

In order to control the etching speed of each thin film constituting the phase reversal film 104, the injection rate of each gas may be varied during the sputtering process, and the reactive gas and the inert gas are mixed at a ratio of 0.5: 9.5 to 4: 6 , And finely adjusted at a ratio of 1: 9 to 3: 7.

It is preferable that the light shielding film 110 is formed in a laminated form of the light shielding film 106 and the antireflection film 108. The light shielding film 110 is an example of a single layer, Or a laminated layer of a continuous film.

The light shielding film 110 is formed of a material having an etch selectivity with respect to the phase reversal film 104. For example, Cr (Cr), CrN, CrC, CrCO, CrON, CrCN, CrCON As shown in Fig.

Referring to FIG. 3B, after the resist film pattern 114a is formed by performing exposure and development processes on the resist film, the light shielding film is etched using the resist film pattern 114a as an etching mask, (110a).

Referring to FIG. 3C, the phase reversal film under the resist film pattern and the light shielding film pattern 110a is etched using an etching mask to form a phase reversal film pattern 104a made of a multilayer film.

Although not shown, a phase reversal film pattern 104a made of a multilayer film can be formed by removing the resist film pattern and etching the phase reversal film below the light shielding film pattern 110a using an etching mask.

At this time, the etching process for forming the light shielding film pattern 110a and the phase inverting film pattern 104a is performed by one of wet etching and dry etching, and is preferably performed by a wet etching process. Here, when each thin film constituting the phase reversal film 104 is composed of molybdenum silicide (MoSi) or a compound thereof, wet etching can be performed by using ammonia hydrogendifluoride [(NH4) HF2], hydrogen peroxide (H2O2) it is preferable to use an etching solution containing water as a main component. In addition, various methods and materials known in the art can be used for the etching material and the etching method of the wet etching process.

3D, a resist film pattern (not shown) is formed on the light-shielding film pattern, and then the light-shielding film pattern is etched to form a light-shielding film pattern 110b on the phase reversal film pattern 104a Thereby completing the fabrication of the phase reversal photomask 200 having a rim-type structure for forming a contact or a line pattern. This can prevent a side-lobe phenomenon of phase inversion.

3E, the phase reversal photomask 200 in which the light shielding film pattern 110b remains on the edge portion phase inverting film pattern 104a to complete the blind area is completed.

3F, the phase reversal photomask 200 completely removes the light shielding film pattern on the phase reversal film pattern 104a after the step of FIG. 3B described above, Only the reversal film pattern 104a may be remained.

4 is a cross-sectional view showing a phase-reversal photomask according to a second embodiment of the present invention.

4, a phase reversal photomask 300 according to the present invention includes a phase reversal film pattern 104a formed of a multilayer film of two or more layers in a main region of a transparent substrate 102, At least the light-shielding film pattern 110b is provided so as to have an auxiliary pattern as shown in Fig.

The phase reversal photomask 300 forms the light shielding film pattern and the resist film pattern on the transparent substrate 102 and then forms the light shielding film pattern 110b by etching the light shielding film with the resist film pattern as an etching mask.

Subsequently, a multilayer phase reversal film is formed on the transparent substrate 102 including the light-shielding film pattern 110b, a resist film pattern is formed on the phase reversal film, and then the phase reversal film is etched to form the phase reversal film pattern 104a. .

Here, although not shown, the light shielding film pattern 110b may be partially disposed under the phase reversal film pattern of the main area required.

The phase inversion blank mask according to the embodiment of the present invention may have a structure including a thin metal film serving as an etching mask of the phase reversal film on the multilayer phase reversal film.

5 is a cross-sectional view showing a phase inversion blank mask according to a third embodiment of the present invention.

5, a phase inversion blank mask 400 according to the present invention includes a phase reversal film 204, a metal film 212, and a resist film 214 sequentially formed on a transparent substrate 202.

Here, the phase reversal film 204 has the same structural and physical, chemical, and optical configuration and physical properties as the phase reversal film in the above-described embodiments.

The metal film 212 is formed in the form of a pattern to serve as an etch mask for the phase reversal film 204 so that the metal film 212 is etched to a depth As shown in Fig.

The metal film 212 is formed of a metal such as Cr, Al, Co, W, Mo, V, Pd, Ti, Pt, manganese, iron, nickel, cadmium, zirconium, magnesium, lithium, selenium, copper, yttrium, Y, at least one of a sulfur (S), indium (In), tin (Sn), beryllium (Be), sodium (Na), tantalum (Ta), hafnium (Hf), and niobium Or one or more light element materials selected from the group consisting of oxygen (O), nitrogen (N), and carbon (C).

The metal film 212 may be formed by depositing oxygen (O), nitrogen (N), or the like on the chromium (Cr) alone or chromium (Cr) when the phase reversal film 204 is made of molybdenum silicide (MoSi) , Carbon (C), and a chromium (Cr) compound. At this time, the metal film 212 is formed to have a composition of 30 at% to 100 at% of Cr, 20 at% to 50 at% of nitrogen (N), 0 at% to 30 at% of oxygen (O) %.

The metal film 212 has a thickness of 10 Å to 700 Å, and preferably has a thickness of 50 Å to 400 Å. The metal film 212 is excellent in adhesion to the resist film 214 disposed on the top and the resist film 214 used as an etching mask for the metal film 212 has a very thin thickness of the metal film 212 , And has a thickness of 8,000 or less, preferably 6,000 or less.

The metal film and the resist film can also be formed to have a thickness to be formed in a binary blank mask which is usually used according to the product level or necessity.

The phase inversion blank mask 400 according to the embodiment of the present invention can be fabricated as a phase inversion photomask using the same process as in the above embodiments.

Here, the phase inversion photomask may also be a mode in which only the phase reversal film pattern is formed on the transparent substrate in the same manner as in the above embodiments and FIGS. 3d, 3e, 3f and 4, The shape in which the film pattern remains, the shape in which only the phase reversal film pattern remains in the main region, and the like.

As described above, according to the present invention, since a thin metal film is used as the etching mask of the phase reversal film, the thickness of the resist film can be made very thin as compared with the prior art, so that the loading effect is remarkably reduced and a highly accurate metal film pattern is formed And the phase reversal film pattern etched by the metal film pattern with the etching mask can be formed to have high precision CD.

Also, since the metal film has excellent adhesion to the resist film, the etching material can penetrate into the interface during the patterning of the phase reversal film to prevent the cross section of the phase reversal film pattern from being inclined.

In addition, although not shown, the phase-reversal photomask may further include a light-shielding film pattern provided on the upper or lower portion of the phase reversal film pattern for a predetermined role such as a shielding function.

Fig. 6 is a cross-sectional view showing the boundary surface of the phase reversal film pattern according to the embodiments of the present invention. Fig.

Referring to FIG. 6, the multi-layered phase reversal film pattern 104a according to the present invention may be formed as a thin film which is formed so that the etching rate of the lower film is faster than that of the upper film, And the Sidewall Angle can be formed to be excellent.

At this time, the horizontal distance (tail size: d) between the upper edge and the lower edge of the phase reversal film pattern 104a is 100 nm or less, preferably 60 nm or less. The upper surface of the phase reversal film pattern 104a and the end surface of the pattern edge portion have an angle of 70 deg. To 110 deg. And preferably an angle of 80 deg. To 100 deg.

In addition, the phase inversion blank mask and the photomask according to the present invention may further include a thin film such as an etching stopper film, a semi-transparent film, a hard film, etc. provided on at least one of upper and lower portions of a phase reversal film or a light- .

According to another aspect of the present invention, there is provided a phase inversion photomask fabricated using a phase inversion blank mask having the above-described configuration, comprising: a phase reversal film pattern made of at least two or more multi- Wherein each film constituting the phase reversal film pattern is made of a metal silicide compound containing at least one of oxygen (O), nitrogen (N) and carbon (C), and i-line (365 nm), h There is provided a phase inversion photomask having a reflectance of 35% or less with respect to exposure light of a composite wavelength including a line (405 nm) and a g line (436 nm).

(Example)

Molybdenum silicide ( MoSi ) Compound Multilayer Of the phase reversal film  Manufacturing and Evaluation

In the embodiment of the present invention, a manufacturing method for a phase inversion blank mask in which a phase reversal film and a light blocking film are sequentially laminated on a transparent substrate will be described.

First, a synthetic quartz glass substrate having a size of 800 mm x 920 mm was prepared. A phase reversal film of a three-layer structure was formed on the substrate by using a DC magnetron sputtering apparatus and using MoSi [10: 90 at%] Target. The first layer adjacent to the transparent substrate in detail was deposited at Ar: N ₂ = 90: 18 sccm and the process power at 1.6 kW. The second layer was Ar: N ₂ = 90: 22 sccm, the process power was 1.7 kW, , Ar: N ₂ = 90: 24 sccm, and the process power was 1.75 kW. At this time, the tray speed was the same at 90 mm / sec. As a result of measuring the thickness of the phase reversal film after the deposition as described above, the first layer film was 34.5 nm, the second layer film was 35.2 nm, and the third layer film was 33.8 nm, and the total thickness was 103.5 nm.

7 showing the reflectance and transmittance according to the embodiment of the present invention, the transmittance was 4.65% at i-line, 7.52% at h-line, and 10.10% at g-line, The deviation was 5.45%. The reflectance was 21.45% in the i-line, 22.01% in the h-line and 21.39% in the g-line, and the lowest point was observed at 604 nm.

On the other hand, the amount of phase was 182 ° in the i-line, 168 ° in the h-line, and 153 ° in the g-line.

Thereafter, a chromium (Cr) target was used and a light-shielding film having a two-layer structure was formed to a thickness of 105 nm. Optical density after the formation of the light-shielding film was measured to be 3.5 in the i-line.

Thereafter, a resist film was coated on the light-shielding film to a thickness of 500 nm to complete the final phase inversion blank mask.

The manufacture of the photomask was carried out using the blank mask prepared as described above.

First, a resist film pattern is formed through an exposure and development process using the blank mask, and then the lower light-shielding film pattern is wet-etched using the resist film pattern as an etching mask.

Thereafter, the resist film was removed and the phase reversal film was wet-etched again using the light-shielding film pattern. An etching solution consisting of Ammonium Hydrodifluoride, Hydrogen peroxide and DI-Water was used as the phase reversal film etching solution. After coating the resist film again, the main area except for the blind area of the outer peripheral part was exposed and developed, and then the light shielding film of the main area was completely removed to finally manufacture the photomask.

The pattern cross-sectional shape of the photomask was measured by FE-SEM, and the sidewall angle of the photomask was measured. Referring to FIG. 8 illustrating a cross-sectional view of a photomask pattern according to an embodiment of the present invention, it can be seen that the cross section of the phase reversal film pattern of the photomask has a vertical shape of about 80 degrees or more.

(Comparative Example 1)

Molybdenum silicide ( MoSi ) Compound single layer Of the phase reversal film  Manufacturing and Evaluation

In this Comparative Example 1, a phase reversal film having a single-layer structure was prepared and evaluated for comparison with the above-mentioned Examples.

The phase reversal film according to the comparative example 1 uses the same substrate and equipment as those of the above embodiment and uses a MoSi [10: 90 at%] target and injects Ar: N ₂ = 90 sccm: 24 sccm as a process gas, A phase reversal film of a single layer was formed to a thickness of 109 nm under the film formation condition of 1.75 kW.

9 showing the reflectance and transmittance according to Comparative Example 1 of the present invention, the transmittance was 3.55% in the i-line, 6.43% in the h-line, and 8.38% in the g-line, The phase shifts were 190.6 °, 174.1 ° and 162.7 °, respectively, so that there was no problem in using it as a phase reversal film for a composite wavelength.

Thereafter, a light shielding film was formed using a chromium target in the same manner as in the above example, and then a resist film was similarly coated to a thickness of 500 nm to complete the manufacture of a phase inversion blank mask. Then, after the photomask manufacturing process was performed in the same manner as in the above example, the pattern cross-sectional shape of the photomask was measured by FE-SEM, and the sidewall angle of the photomask was measured.

At this time, referring to FIG. 10 showing a cross-sectional photograph of the photomask pattern according to Comparative Example 1, it can be seen that the cross-section of the single-phase phase reversal film pattern of the photomask has a relatively bad pattern cross- there was.

(Comparative Example 2)

Molybdenum silicide ( MoSi ) Depending on the composition of the compound, Of the phase reversal film  Manufacturing and Evaluation

In this Comparative Example 2, the phase reversal film of a multilayer structure was produced by decreasing the proportion of nitrogen (N) to the upper portion, and a photomask was formed to evaluate the cross-sectional shape of the phase reversal film pattern.

For this, a phase reversal film was formed using the same substrate and equipment as those of the above embodiment, and a MoSi [10: 90 at%] target was used to form a three-layered phase reversal film.

Ar: N ₂ = 90 sccm: 26 sccm, the process power is 1.35 kW, the third layer is Ar: N ₂ = 50 sccm: 50 sccm, the process power is 1.2 kW, N ₂ = 90 sccm: 18 sccm, and a process power of 1.45 kW.

11, which shows the reflectance and transmittance according to Comparative Example 2, the transmittance was 4.35% at the i-line, 6.91% at the h-line, and 9.27% at the g-line. 4.92%, and the amount of phase was 181 degrees in the i-line, 165 degrees in the h-line, and 151 degrees in the g-line.

However, as the nitrogen content of the surface of the reflectance decreased, the reflectance was higher by 30% or more at 32.35% in the i-line, 33.33% in the h-line and 33.13% in the g-line. Respectively.

Thereafter, a light shielding film was formed using a chromium target in the same manner as in the above example, and then a resist film was similarly coated to a thickness of 500 nm to complete the manufacture of a phase inversion blank mask.

Then, after the photomask manufacturing process was performed in the same manner as in the above example, the pattern cross-sectional shape of the photomask was measured by FE-SEM, and the sidewall angle of the photomask was measured.

12, which shows a cross-sectional photograph of the photomask pattern according to Comparative Example 2, the cross-section of the single-phase phase reversal film pattern of the photomask has a pattern cross-sectional shape of less than about 40 degrees, which is the worst I could confirm. This is because the content of nitrogen (N) contained in the uppermost layer is relatively low and the content of nitrogen (N) contained in the lowermost portion is high.

While the present invention has been described with reference to the preferred embodiments, the technical scope of the present invention is not limited to the range described in the above embodiments. It will be readily apparent to those skilled in the art that various changes and modifications can be made to the embodiments described above. It is apparent from the description of the claims that the form of such modification or improvement can be included in the technical scope of the present invention.

100: Phase inversion blank mask for FPD
102, 202: transparent substrate
104, 204: multilayer phase reversal film
106: a light-shielding film
108: antireflection film
110: Shading film
212: metal film

Claims (17)

1. A phase inversion blank mask having a phase reversal film on a transparent substrate,
Wherein the phase reversal film is composed of a multilayer film of at least two layers including a metal silicide,
Wherein the uppermost layer of the multilayered film has a nitrogen (N) content higher than that of the underlying layers.
The method according to claim 1,
Characterized in that the film constituting the phase reversal film includes at least one of oxygen (O), nitrogen (N) and carbon (C) in molybdenum silicide (MoSi) or molybdenum silicide (MoSi) Mask.
3. The method of claim 2,
Wherein the film constituting the phase reversal film has a composition of 2 at% to 30 at% of molybdenum (Mo), 20 at% to 70 at% of silicon (Si), 5 at% to 50 at% of nitrogen (N) And carbon (C) is contained in an amount of 0 to 30 at%, and carbon (C) is contained in an amount of 0 to 30 at%.
The method according to claim 1,
The film constituting the phase reversal film may be composed of the same composition or may have the same composition and different composition ratios or at least one of oxygen (O), nitrogen (N) and carbon (C) Phase inversion blank mask.
The method according to claim 1,
Wherein the films constituting the phase reversal film have a lower content of nitrogen (N) going from the uppermost film to the transparent substrate.
The method according to claim 1,
Wherein a content of nitrogen (N) is lower in the film adjacent to the transparent substrate than the film of at least one of the upper films among the films constituting the phase reversal film.
The method according to claim 1,
The uppermost film among the films constituting the phase reversal film has a lower oxygen (O) content than at least one of the lower films, or the layer adjacent to the transparent substrate has higher oxygen (O ). ≪ / RTI >
8. The method of claim 7,
Wherein when the uppermost film among the films constituting the phase reversal film contains oxygen (O), oxygen (O) has a content of 30 at% or less, and the uppermost film has a thickness of 30 nm or less.
The method according to claim 1,
The uppermost film among the films constituting the phase reversal film has a higher carbon (C) content than at least one of the lower films, or the layer adjacent to the transparent substrate has lower oxygen (O ). ≪ / RTI >
The method according to claim 1,
Wherein the phase reversal film has a thickness of 500 ANGSTROM to 1,500 ANGSTROM, and each of the films constituting the phase reversal film has a thickness of 50 ANGSTROM to 1,450 ANGSTROM.
11. The method according to any one of claims 1 to 10,
Wherein the phase reversal film is etched in an etching solution containing ammonia hydrogendifluoride [(NH ₄ ) HF ₂ ], hydrogen peroxide (H ₂ O ₂ ), and DI-water as main components.
12. The method of claim 11,
Wherein the ammonia hydrogendifluoride [(NH ₄ ) HF ₂ ] is contained in an amount of 10 vol% or less in the entire etching solution.
The method according to claim 1,
Wherein the phase reversal film has a reflectance of 35% or less with respect to exposure light of a composite wavelength including i-line (365 nm), h-line (405 nm), and g-line (436 nm).
The method according to claim 1,
Wherein the phase reversal film has a lowest reflectance at one of the wavelengths of 400 nm to 900 nm or less.
The method according to claim 1,
Wherein the phase reversal film has a transmittance of 1% to 40% and a transmittance deviation of 10% or less with respect to exposure light of a composite wavelength including i-line, h-line and g-line.
The method according to claim 1,
Characterized in that the phase reversal film has a phase inversion amount of 160 DEG to 200 DEG with respect to exposure light of a composite wavelength including i line, h line and g line, and the phase amount deviation has 40 DEG or less. Mask.
The method according to claim 1,
Further comprising at least one of a light shielding film, a semitransmissive film, an etching stopper film, and an etching mask film provided on the upper or lower portion of the phase reversal film.

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