KR20220115549A - Appratus for fabricating semiconductor device - Google Patents

Abstract

Embodiments relate to an apparatus for manufacturing a semiconductor device which can easily form a micro pattern, and a blank mask. The apparatus for manufacturing a semiconductor device includes: a light source; and a photo mask in which light from the light source is incident, and which selectively transmits the incident light and emits the same to a semiconductor wafer. The photo mask may include: a transparent substrate; a phase inversion layer disposed on the transparent substrate; and a light blocking layer disposed on the phase inversion layer. The photomask is analyzed by normal mode XRD. In the normal mode XRD analysis, the maximum peak of the X-ray intensity measured after reflection in the direction of the phase inversion layer is located between 2θ of 15° and 30°. In the normal mode XRD analysis, the maximum peak of the X-ray intensity measured after reflection in the direction of the transparent substrate is located between 2θ of 15° and 30°. A first amorphous index (AI1) represented by equation 1, AI1 = XM1/XQ1, is 0.9 to 1.1. In equation 1, XM1 is the maximum value of X-ray intensity measured when the normal mode XRD analysis is performed on the phase shift layer. The XQ1 is the maximum value of X-ray intensity measured when the normal mode XRD analysis is performed on the lower surface of the transparent substrate.

Description

Semiconductor device manufacturing apparatus

The embodiment relates to an apparatus for manufacturing a semiconductor device and a blank mask.

BACKGROUND ART Due to high integration of semiconductor devices and the like, miniaturization of circuit patterns of semiconductor devices is required. For this reason, the importance of a lithography technique, which is a technique for developing a circuit pattern on a wafer surface using a photomask, is further highlighted.

In order to develop a miniaturized circuit pattern, a shorter wavelength of an exposure light source used in an exposure process is required. Recently used exposure light sources include ArF excimer lasers (wavelength 193 nm) and the like.

Meanwhile, the photomask includes a binary mask and a phase shift mask.

The binary mask has a structure in which a light blocking layer pattern is formed on a transparent substrate. In the binary mask, the pattern is exposed on the resist film on the wafer surface by the transmissive portion not including the light blocking layer transmits the exposure light, and the light blocking portion including the light blocking layer blocks the exposure light. However, in the binary mask, as the pattern becomes finer, a problem may occur in the fine pattern phenomenon due to diffraction of light generated at the edge of the transmission part during exposure.

The phase shift mask includes a Levenson type, an outrigger type, and a half-tone type. Among them, the halftone phase shift mask has a configuration in which a pattern formed of a semi-transmissive film is formed on a transparent substrate. In the halftone phase shift mask, the transmissive part not including the transflective layer transmits exposure light, and the transflective part including the transflective layer transmits attenuated exposure light. The attenuated exposure light has a phase difference compared with the exposure light passing through the transmission part. Due to this, the diffracted light generated at the edge of the transmissive part is canceled by the exposure light passing through the transflective part, so that the phase shift mask can form a finer fine pattern on the wafer surface.

As related prior art, there are Korean Patent Registration No. 10-1360540, US Patent Publication No. 2004-0115537, Japanese Patent Application Laid-Open No. 2018-054836, and the like.

SUMMARY An embodiment is to provide an apparatus for manufacturing a semiconductor device capable of easily forming a fine pattern and a blank mask.

An apparatus for manufacturing a semiconductor device according to an embodiment includes a light source; and a photomask to which the light from the light source is incident, and selectively transmits the incident light to the semiconductor wafer.

A photomask according to an embodiment includes a transparent substrate; a phase inversion layer disposed on the transparent substrate; and a light blocking layer disposed on the phase shift layer.

The photomask was analyzed by normal mode XRD. When the normal mode XRD analysis proceeds, the maximum peak of the measured X-ray intensity after reflection in the phase reversal layer direction is located between 15° and 30° at 2θ, and when the normal mode XRD analysis proceeds, the lower surface of the transparent substrate 2θ of the measured X-ray intensity after reflection in the direction has a maximum value between 15° and 30°, and the photomask has a first amorphous index (AI1) of 0.9 to 1.1 expressed by Equation 1 below.

[Equation 1]

In Equation 1, XM1 is the maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the phase reversal layer, and XQ1 is the normal mode XRD analysis on the lower surface of the transparent substrate. It is the maximum value of the measured X-ray intensity.

In an embodiment, the phase shift layer includes a phase difference adjustment layer disposed on the transparent substrate and a protective layer disposed on the phase difference adjustment layer. The phase shift layer includes a transition metal, silicon, oxygen, and nitrogen. The phase difference adjusting layer may contain 40 to 60 atomic % of nitrogen, and the protective layer may contain 20 to 40 atomic % of nitrogen.

The passivation layer includes a region in which the ratio of nitrogen content to oxygen content in the thickness direction belongs to 0.4 to 2, and the region has a thickness of 30 to 80% when the total thickness of the passivation layer is 100%.

In one embodiment, when the thickness of the phase shift layer is 100%, the thickness of the passivation layer is 4 to 9%, the thickness of the passivation layer is 25 Å or more and 80 Å or less, and the retardation adjusting layer has a refractive index of 2 to 9%. 4, and the extinction coefficient is 0.3 to 0.7.

In an embodiment, the light blocking layer includes chromium and nitrogen, and 44 to 60 atomic % of the chromium, and the total optical density from the lower surface of the phase inversion layer to the upper surface of the light blocking layer is 3 or more.

In an embodiment, the photomask is analyzed by fixed-mode XRD, and in the fixed-mode XRD analysis, the first peak, which is the maximum peak of the X-ray intensity measured after reflection in the direction of the phase reversal layer, has a 2θ of 15° to 25° The second peak, which is the maximum peak of the X-ray intensity measured after reflection in the direction of the transparent substrate in the fixed mode XRD analysis, is located between 15° to 25°, and the photomask is expressed by the following Equation 2 The displayed second amorphous index AI2 is 0.9 to 1.1.

[Equation 2]

In Equation 2, XM2 is the intensity value of the first peak, and XQ2 is the intensity value of the second peak.

In an embodiment, the photomask has a third amorphous index (AI3) of 0.9 to 1.1 expressed by Equation 3 below.

[Equation 3]

In Equation 3, AM1 is an area in a region where 2θ is between 15° and 30° in the X-ray intensity graph measured after reflection when normal mode XRD analysis is performed on the phase reversal layer, and AQ1 is the transparent It is the area in the region where 2θ is between 15° and 30° in the X-ray intensity graph measured after reflection when normal mode XRD analysis is performed on the lower surface of the substrate.

In an embodiment, the photomask has a fourth amorphous index (AI4) of 0.9 to 1.1 expressed by Equation 4 below.

[Equation 4]

In Equation 4, XM4 is the X-ray intensity reflected when 2θ is 43° in the normal mode XRD analysis performed on the phase reversal layer, and XQ4 is the normal mode XRD analysis performed on the lower surface of the transparent substrate. , is the reflected X-ray intensity when 2θ is 43°.

A blank mask according to an embodiment includes a transparent substrate; and a phase reversal layer disposed on the transparent substrate, wherein the photomask is analyzed by normal mode XRD, and the maximum peak of the measured X-ray intensity after reflection in the direction of the phase reversal layer in the normal mode XRD analysis is 2θ is located between 15° and 30°, the maximum peak of the X-ray intensity measured after reflection in the direction of the transparent substrate in the normal mode XRD analysis is located between 15° and 30° in 2θ, and the photomask is The first amorphous index (AI) represented by 1 is 0.9 to 1.1.

A blank mask according to an embodiment includes a transparent substrate; a phase inversion layer disposed on the transparent substrate; and a light blocking layer disposed on the phase shift layer. When the normal mode XRD analysis is performed through the light-shielding layer, 2θ of the measured X-ray intensity after reflection has a maximum value between 15° and 30°, and through the lower surface of the transparent substrate, when the XRD analysis is performed , 2θ of the measured X-ray intensity after reflection has a maximum value between 15° and 30°, and the photomask has a fifth amorphous index (AI5) of 0.9 to 0.97, expressed by Equation 5 below.

[Equation 5]

In Equation 5, the XC1 is the maximum value of the X-ray intensity measured through the light blocking layer, and the XQ1 is the maximum value of the X-ray intensity measured through the lower surface of the transparent substrate.

In an embodiment, the blank mask may have a sixth amorphous index (AI6) of 1.05 to 1.4 expressed by Equation 6 below.

[Equation 6]

In Equation 6, XC4 is the X-ray intensity reflected when 2θ is 43° when the normal mode XRD analysis is performed in the direction of the light blocking layer, and XQ4 is the normal mode XRD in the direction of the lower surface of the transparent substrate As the analysis proceeds, the reflected X-ray intensity when 2θ is 43°.

Since the first amorphous index has the above range, the phase shift layer and the transparent substrate have very similar crystal properties.

In addition, since the second amorphous index has the above range, the phase shift layer and the transparent substrate have very similar crystal properties.

In addition, since the third amorphous index has the above range, the phase shift layer and the transparent substrate have very similar crystal properties.

In addition, since the fourth amorphous index has the above range, the phase shift layer and the transparent substrate have very similar crystal properties.

Accordingly, optical distortion due to a difference in crystal characteristics between the phase shift layer and the transparent substrate may be minimized. That is, since the phase shift layer and the transparent substrate have similar crystal properties according to XRD analysis, the photomask may have improved optical performance.

In particular, since the transparent substrate and the phase shift layer have similar crystal properties, optical distortion generated at the interface between the transparent substrate and the phase shift layer is reduced when the transparent substrate and the phase shift layer are in direct contact with each other. can be

In addition, since the fifth amorphous index has the above range, the light blocking layer and the transparent substrate have different crystal properties.

Since the sixth amorphous index has the above range, the light blocking layer and the transparent substrate have different crystal properties.

Accordingly, the light blocking layer may have improved light blocking performance.

Accordingly, the apparatus for manufacturing a semiconductor device according to the embodiment may reduce process errors due to optical distortion in exposure and development processes. Accordingly, the apparatus for manufacturing a semiconductor device according to the embodiment can easily manufacture a semiconductor device having improved fine line width characteristics.

1 is a schematic diagram illustrating an exposure apparatus according to an exemplary embodiment.
2 is a cross-sectional view illustrating a photomask according to an exemplary embodiment.
3 and 4 are cross-sectional views illustrating a blank mask according to an embodiment, respectively.
5 is a schematic diagram illustrating a normal mode XRD analysis process.
6 is a schematic diagram illustrating a fixed mode XRD analysis process.
7 is a diagram illustrating X-ray intensity measured by performing normal mode XRD analysis on a phase inversion layer in a blank mask according to an exemplary embodiment;
8 is a view illustrating X-ray intensity measured by performing normal mode XRD analysis on a transparent substrate in a blank mask according to an embodiment.
FIG. 9 is a diagram illustrating X-ray intensity measured by performing normal mode XRD analysis on a light blocking layer in a blank mask according to an exemplary embodiment.
10 is a diagram illustrating X-ray intensity measured by performing fixed mode XRD analysis on a phase inversion layer in a blank mask according to an embodiment.
11 is a diagram illustrating X-ray intensity measured by performing fixed mode XRD analysis on a transparent substrate in a blank mask according to an exemplary embodiment;
12 is a view illustrating X-ray intensity measured by performing fixed mode XRD analysis on a light blocking layer in a blank mask according to an exemplary embodiment;

Hereinafter, the embodiments will be described in detail so that those of ordinary skill in the art to which the embodiments belong can easily implement them. However, the embodiment may be implemented in various different forms and is not limited to the embodiment described herein.

As used herein, the terms "about," "substantially," and the like are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and to aid understanding of embodiments. It is used to prevent an unconscionable infringer from using the mentioned disclosure unfairly.

Throughout this specification, the term "combination of these" included in the expression of the Markush form means one or more mixtures or combinations selected from the group consisting of the components described in the expression of the Markush form, and the components It is meant to include one or more selected from the group consisting of.

Throughout this specification, reference to “A and/or B” means “A, B, or A and B”.

Throughout this specification, terms such as “first”, “second” or “A” and “B” are used to distinguish the same terms from each other unless otherwise specified.

In this specification, the meaning that B is located on A means that B is located on A or B is located on A while another layer is located between them, and B is located in contact with the surface of A It is not construed as being limited to

In the present specification, unless otherwise specified, the expression "a" or "a" is interpreted as meaning including the singular or the plural as interpreted in context.

In the present specification, the drawings are presented for description of the embodiments, and parts thereof may be exaggerated or omitted, and are not drawn to scale.

In the present specification, the transmissive part TA refers to an area that does not substantially include a phase shift layer on the surface of the photomask on which the pattern is formed on the transparent substrate and transmits exposure light, and the transflective part NTA refers to the phase shift layer substantially on the surface of the transparent substrate. It refers to a region that transmits the attenuated exposure light, including (see FIG. 2 ).

A process of manufacturing a semiconductor device includes a process of forming a designed pattern by forming an exposure pattern on a semiconductor wafer. Specifically, when a photomask including a designed pattern is placed on a semiconductor wafer coated with a resist layer on the surface and exposed through a light source, the resist layer of the semiconductor wafer forms a designed pattern after treatment with a developing solution. .

As semiconductors are highly integrated, more miniaturized circuit patterns are required. In order to form a miniaturized pattern on a semiconductor wafer, exposure light having a shorter wavelength than conventional exposure light may be applied. The exposure light for forming the finer pattern includes, for example, an ArF excimer laser (wavelength 193 nm).

Accordingly, the layers included in the photomask to form a pattern are required to have improved optical properties.

In addition, a light source that generates exposure light having a short wavelength may require high output. Such a light source may increase the temperature of the photomask included in the semiconductor device manufacturing apparatus in the exposure process.

Accordingly, the layers included in the photomask to form a pattern may exhibit a characteristic in which physical properties such as thickness and height change according to temperature change. The layers included in the photomask to form a pattern are also required to have improved thermal properties.

The photomask is not entirely formed of the same material, but has a multi-layered structure of at least two or more layers when viewed in cross-section. Therefore, the characteristics of the blank mask, which is a laminate including a phase reversal film and a transparent substrate, also affects the physical properties of the photomask, and in some cases undergoes oxidation treatment, heat treatment, etc. during the manufacturing process, the characteristics and completion of the first laminated material itself There is also a difference between the characteristics of the blank mask.

Crystal characteristics of each layer included in the photomask may be appropriately adjusted so that optical properties and thermal properties of each layer included in the photomask may be improved.

The inventors of the embodiment control the crystal characteristics of the films included in the photomask in the semiconductor device manufacturing apparatus within a certain range, so that the temperature of the photomask is increased by the light source that generates exposure light of a short wavelength, or the difference in the optical properties of each layer The embodiment was completed by experimentally confirming that it is possible to substantially suppress the reduction in resolution of the pattern exposed on the generated wafer.

Hereinafter, implementations are described in more detail.

1 is a schematic diagram illustrating an exposure apparatus according to an exemplary embodiment. 2 is a cross-sectional view illustrating a photomask according to an exemplary embodiment. 3 and 4 are cross-sectional views illustrating a blank mask according to an embodiment, respectively. 5 is a schematic diagram illustrating a normal mode XRD analysis process. 6 is a schematic diagram illustrating a fixed mode XRD analysis process. 7 is a diagram illustrating X-ray intensity measured by performing normal mode XRD analysis on a phase inversion layer in a blank mask according to an exemplary embodiment; 8 is a view illustrating X-ray intensity measured by performing normal mode XRD analysis on a transparent substrate in a blank mask according to an embodiment. FIG. 9 is a diagram illustrating X-ray intensity measured by performing normal mode XRD analysis on a light blocking layer in a blank mask according to an exemplary embodiment. 10 is a diagram illustrating X-ray intensity measured by performing fixed mode XRD analysis on a phase inversion layer in a blank mask according to an embodiment. 11 is a diagram illustrating X-ray intensity measured by performing fixed mode XRD analysis on a transparent substrate in a blank mask according to an exemplary embodiment; 12 is a diagram illustrating X-ray intensities measured by performing fixed mode XRD analysis on a light blocking layer in a blank mask according to an exemplary embodiment;

semiconductor device manufacturing apparatus

Referring to FIG. 1 , an apparatus for manufacturing a semiconductor device according to an exemplary embodiment includes a light source, an optical system, and a photomask. The optical system includes a condensing lens and a projection lens. An apparatus for manufacturing a semiconductor device according to an embodiment is a photolithography system.

The light source 10a is a device capable of generating exposure light having a short wavelength. The exposure light may be light having a wavelength of 200 nm or less. Specifically, the exposure light may be ArF light having a wavelength of 193 nm.

The light source generates light. The light source may be an ArF lamp. The light source may generate ultraviolet light. The wavelength of light generated from the light source may be about 193 nm.

The condensing lens 20a condenses the light from the light source to the photomask.

The photomask 30a selectively transmits the light from the light source and is emitted to the semiconductor wafer. In more detail, the light emitted from the condensing lens is selectively transmitted through the photomask, and the selectively transmitted light is emitted to the projection lens 40a. The projection lens focuses the light incident from the photomask and emits it to the semiconductor wafer 50a.

In the semiconductor device manufacturing apparatus, the projection lens may be positioned between the photomask and the semiconductor wafer. The projection lens has a function of reducing the shape of the circuit pattern on the photomask and transferring it onto the semiconductor wafer. The projection lens is not limited as long as it can be generally applied to an ArF semiconductor wafer exposure process. Illustratively, the projection lens may be a lens made of calcium fluoride (CaF ₂ ).

The semiconductor wafer may be a semiconductor substrate including a photoresist layer on top. The light selectively transmitted by the photomask and the optical system may develop the semiconductor wafer. In more detail, the light selectively transmitted by the photomask and the optical system may develop the photoresist layer. That is, a photolithography process may be performed by the light source, the optical system, and the photomask.

photo mask

As shown in FIG. 2 , the photomask includes a transparent substrate 10 , a phase reversal layer 20 disposed on the transparent substrate 10 , and a light blocking layer 30 disposed on the phase reversal layer 20 . ) is included.

The transparent substrate 10 serves to transmit exposure light to the thin film formed on the transparent substrate 10 .

The phase shift layer 20 in the photomask 200 may include a pattern to be transferred. The light blocking layer 30 in the photomask 200 may include a preset pattern.

The phase shift layer 20 transmits only a portion of the exposure light passing through the phase shift layer 20 , and adjusts a phase difference between the partially transmitted exposure light to improve the resolution of the pattern to be developed.

The light blocking layer 30 may block transmission of the exposure light reaching the surface of the light blocking layer 30 .

The photomask 200 may be manufactured as a blank mask 100 to be described below.

Specific description of the layer structure, optical properties, composition and sputtering method, patterning method, etc. of the transparent substrate 10, the phase reversal layer 20 and the light blocking layer 30 in the photomask 200, the blank mask and photo Since it overlaps with the description of the mask manufacturing method, it is omitted.

The optical properties of the phase shift layer 20 are determined according to various factors such as the composition of elements constituting the film, the density of the film, and the thickness of the film. Therefore, in order to maximize the resolution of the pattern to be developed on the semiconductor wafer, the phase inversion layer 20 is designed and then deposited in consideration of the above factors. However, the temperature of the phase reversal layer 20 may increase due to heat generated from the light source during the exposure process, and the thickness value, stress, etc. of the phase reversal layer 20 may vary due to the heat.

The elements constituting the phase reversal layer 20, the content of each element, the magnetic field strength in the sputtering process, the substrate rotation speed, the voltage applied to the target, the atmospheric gas composition, the sputtering temperature, the conditions during the post-processing process, etc. can

When the phase reversal layer 20 is formed using sputtering equipment, a magnet is placed in the sputtering equipment and a magnetic field is formed to distribute plasma over the entire surface of the target in the chamber. In addition, the distribution, strength, etc. of the magnetic field may affect the density of the film formed by sputtering equipment.

Specifically, the stronger the magnetic field strength, the higher the density of plasma formed in the chamber, so that the deposited phase inversion layer 20 may be dense. The weaker the magnetic field strength, the lower the density of plasma formed in the chamber, so that the phase inversion layer 20 formed may be eliminated.

The phase shift layer 10 of the photomask 200 is formed by patterning after the light blocking layer 30 positioned on the phase shift layer 10 is removed. When the photomask 20 further includes another layer between the phase shift layer 20 and the light blocking layer 30 , the other layer is also removed. That is, the blank mask 200 is processed so that the outermost surface of the phase reversal layer 20 is exposed, and the photomask is formed. A method of removing the light blocking layer 30 and the other layers includes an etching method using an etchant, but is not limited thereto.

blank mask

3 , the blank mask 100 includes a transparent substrate 10 , a phase shift layer 20 disposed on the transparent substrate 10 , and a light blocking layer disposed on the phase shift layer 20 . layer 30 .

The material of the transparent substrate 10 is not limited as long as it has light transmittance to exposure light and can be applied to the photomask. Specifically, the transmittance of the transparent substrate 10 with respect to exposure light having a wavelength of 200 nm or less may be 85% or more. The transmittance may be 87% or more. For example, the transparent substrate 10 may be a synthetic quartz substrate. In this case, the transparent substrate 10 may suppress attenuation of light passing through the transparent substrate 10 .

In addition, the transparent substrate 10 may reduce the occurrence of optical distortion by adjusting surface characteristics such as flatness and roughness.

phase inversion layer

The phase shift layer 20 may be positioned on the front side of the transparent substrate 10 .

The phase shift layer 20 may include a retardation adjusting layer 21 positioned on the upper surface of the transparent substrate and a protective layer 22 positioned on the retardation adjusting layer 21 .

The phase shift layer 20 , the phase difference adjustment layer 21 , and the passivation layer 22 may each include a transition metal, silicon, oxygen, and nitrogen.

The phase difference adjusting layer 21 is a layer in which the transition metal, silicon, oxygen, and nitrogen are uniformly included within the range of 5 atomic % in the depth direction in the phase shift layer 20 . The phase difference adjusting layer 21 may substantially adjust the phase difference and transmittance of the exposure light passing through the phase shift layer 20 .

Specifically, the phase difference adjusting layer 21 has a characteristic of shifting the phase of the exposure light incident from the back side (lower surface) side of the transparent substrate 10 . Due to these characteristics, the phase shift layer 20 effectively cancels the diffracted light generated at the edge of the transmission part in the photomask, so that the resolution of the photomask is further improved during the lithography process.

In addition, the phase difference adjustment layer 21 attenuates the exposure light incident on the surface of the phase shift layer 20 . Through this, the phase shift layer 20 may appropriately block the exposure light while canceling the diffracted light.

The protective layer 22 is formed on the surface of the phase reversal layer, and has a distribution in which the oxygen content is continuously decreased in the depth direction from the surface and the nitrogen content is continuously increased. The protective layer 22 may improve the durability of the phase shift layer by suppressing damage to the phase shift layer pattern or unnecessary etching in the etching process and cleaning process of the photomask. In addition, the protective layer 22 may partially suppress the occurrence of optical characteristic fluctuations due to oxidation of the retardation adjusting layer 21 due to exposure light in the exposure process.

In the blank mask 100 , the light blocking layer 30 is disposed on the phase inversion layer. The light blocking layer 30 may be used as an etching mask for the phase shift layer 20 when the phase shift layer 20 is etched according to a pattern shape. In addition, the light blocking layer 30 may block transmission of the exposure light incident from the rear side of the transparent substrate 10 .

The light blocking layer may have a single-layer structure. The light blocking layer may have a multi-layer structure of two or more layers. The light blocking layer may be formed through sputtering. The light blocking layer may have a multilayer structure of two or more layers according to sputtering control conditions.

The phase shift layer 20 may include a transition metal, silicon, oxygen, and nitrogen. The transition metal may be one or more elements selected from molybdenum (Mo), tantalum (Ta), zirconium (Zr), and the like, but is not limited thereto. Exemplarily, the transition metal may be molybdenum.

The phase shift layer 20 may contain 1 to 10 atomic % of the transition metal. The phase shift layer 20 may contain 2 to 7 atomic % of the transition metal. The phase shift layer 20 may contain 15 to 60 atomic % of silicon. The phase shift layer 20 may contain 25 to 50 atomic % of silicon. The phase shift layer 20 may contain 30 to 60 atomic % nitrogen. The phase shift layer 20 may contain 35 to 55 atomic% nitrogen. The phase shift layer 20 may contain 5 to 35 atomic % oxygen. The phase shift layer 20 may contain 10 to 25 atomic % oxygen. In this case, the phase shift layer 20 may have optical properties suitable for a lithography process using exposure light having a short wavelength, specifically, light having a wavelength of 200 nm or less.

The phase shift layer 20 may additionally include other elements in addition to the above-mentioned elements. For example, the phase shift layer 20 may include argon (Ar), helium (He), or the like.

The phase shift layer 20 may have a different content for each element in the thickness direction.

The content distribution for each element formed in the depth direction of the phase difference adjusting layer 21 and the protective layer 22 may be confirmed by measuring a depth profile of the phase reversal layer. For example, the depth profile may be measured using the K-alpha model of Thermo Scientific.

The phase difference adjusting layer 21 and the protective layer 22 may have different content of each element such as a transition metal, silicon, oxygen, and nitrogen for each layer.

The phase difference adjusting layer 21 may contain 3 to 10 atomic % of a transition metal. The phase difference adjusting layer 21 may contain 4 to 8 atomic % of a transition metal. The phase difference adjusting layer 21 may contain 20 to 50 atomic % of silicon. The phase difference adjusting layer 21 may contain 30 to 40 atomic % of silicon. The phase difference adjusting layer 21 may contain 2 to 10 atomic % oxygen. The phase difference adjusting layer 21 may contain 3 to 8 atomic% oxygen. The phase difference adjusting layer 21 may contain 40 to 60 atomic % nitrogen. The phase difference adjusting layer 21 may contain 45 to 55 atomic % nitrogen. In this case, it is possible to provide a blank mask having excellent pattern resolution when short-wavelength exposure light, specifically, light having a wavelength of 200 nm or less, is applied as exposure light when manufacturing a photomask.

As the protective layer 22 contains more oxygen, the phase difference adjusting layer 21 can be stably protected from exposure light and a cleaning solution, but the degree of optical characteristic variation of the entire phase reversal layer 20 may be increased. Accordingly, by controlling the content distribution of oxygen and nitrogen in the protective layer 22 , the phase inversion layer 20 may have sufficient light resistance and chemical resistance while having desired optical properties.

The protective layer 22 may contain 20 to 40 atomic % nitrogen. The protective layer 22 may contain 25 to 35 atomic % nitrogen. The protective layer 22 may contain 10 to 50 atomic % oxygen. The protective layer 22 may contain 20 to 40 atomic % oxygen. The protective layer 22 may contain 10 to 50 atomic % of silicon. The protective layer 22 may contain 20 to 40 atomic % of silicon. The protective layer 22 may contain 0.5 to 5 atomic % of the transition metal. The protective layer 22 may contain 1 to 3 atomic % of the transition metal. In this case, the protective layer 22 can sufficiently suppress the deterioration of the phase difference adjusting layer 21 .

The protective layer 22 may include a region in which the nitrogen content (atomic %) to the oxygen content (atomic %) in the thickness direction is 1 or more, and the region has a thickness of 40 to 60% of the total thickness of the protective layer 22 can have The region may have a thickness of 45 to 55% of the total thickness of the protective layer 22 . In this case, fluctuations in the optical properties of the phase reversal layer 20 due to the formation of the protective layer 22 can be effectively suppressed.

The protective layer 22 may include a region in which the ratio of the nitrogen content (atomic %) to the oxygen content (atomic %) in the thickness direction is 0.4 to 2, and the region is the total thickness of the protective layer 22 (100%) It may have a thickness of 30 to 80% of the contrast. The region may have a thickness of 40 to 60% of the total thickness (100%) of the protective layer 22 . In this case, it is possible to provide a blank mask capable of manufacturing a photomask having excellent resolution while having sufficient long-term durability.

The content distribution for each element of the phase reversal layer 20 , the phase difference adjusting layer 21 , and the protective layer 22 and the content distribution for each element formed in the thickness direction can be confirmed by measuring the depth profile. For example, it can be measured through the K-alpha model of Thermo Scientific.

The thickness measurement of the region in which the ratio of the nitrogen content (atomic %) to the oxygen content (atomic %) in the thickness direction is 1 or more may be confirmed by measuring the depth profile. However, it is assumed that the etching rate for each depth of the protective layer 22 is constant in the depth profile.

The thickness measurement of the region in which the ratio of the nitrogen content (atomic %) to the oxygen content (atomic %) in the thickness direction is 0.4 to 2 may be confirmed by measuring the depth profile. However, it is assumed that the etching rate for each depth of the protective layer 22 is constant in the depth profile.

The phase shift layer 20 may have a phase difference of 160 to 200° with respect to light having a wavelength of 200 nm or less. The phase shift layer 20 may have a phase difference of 160 to 200° with respect to ArF light. The phase shift layer 20 may have a phase difference of 170 to 190° for light having a wavelength of 200 nm or less. The phase shift layer 20 may have a phase difference of 170 to 190° with respect to ArF light. The phase shift layer 20 may have a transmittance of 3 to 10% for light having a wavelength of 200 nm or less. The phase shift layer 20 may have a transmittance of 3 to 10% for ArF light. The phase shift layer 20 may have a transmittance of 4 to 8% for light having a wavelength of 200 nm or less. The phase shift layer 20 may have a transmittance of 4 to 8% for ArF light. In this case, the photomask including the phase shift layer 20 may expose a more sophisticated fine pattern on the wafer in an exposure process to which exposure light of a short wavelength is applied.

For example, the phase difference and transmittance of the phase shift layer 20 may be measured through Lasertec's MPM193 model.

The protective layer 22 may have a refractive index of 1.3 to 2 for light having a wavelength of 200 nm or less. The protective layer 22 may have a refractive index of 1.3 to 2 for ArF light. A refractive index of the protective layer 22 with respect to light having a wavelength of 200 nm or less may be 1.4 to 1.8. A refractive index of the protective layer 22 with respect to ArF light may be 1.4 to 1.8. The passivation layer 22 may have an extinction coefficient of 0.2 to 0.4 for light having a wavelength of 200 nm or less. An extinction coefficient for ArF light of the passivation layer 22 may be 0.2 to 0.4. An extinction coefficient for light having a wavelength of 200 nm or less of the protective layer 22 may be 0.25 to 0.35. The passivation layer 22 may have an extinction coefficient of 0.25 to 0.35 for ArF light. In this case, the effect of changing the optical properties of the phase inversion layer 20 due to the formation of the protective layer 22 can be minimized.

The retardation adjusting layer 21 may have a refractive index of 2 to 4 for light having a wavelength of 200 nm or less. The retardation adjusting layer 21 may have a refractive index of 2 to 4 for ArF light. The refractive index of the retardation adjusting layer 21 with respect to light having a wavelength of 200 nm or less may be 2.5 to 3.5. The refractive index of the retardation adjusting layer 21 with respect to ArF light may be 2.5 to 3.5. An extinction coefficient for light having a wavelength of 200 nm or less of the phase difference adjusting layer 21 may be 0.3 to 0.7. The extinction coefficient for ArF light of the phase difference adjusting layer 21 may be 0.3 to 0.7. An extinction coefficient for light having a wavelength of 200 nm or less of the phase difference adjusting layer 21 may be 0.4 to 0.6. The extinction coefficient of the phase difference adjusting layer 21 for ArF light may be 0.4 to 0.6. In this case, the photomask including the phase shift layer 20 may exhibit excellent patterning effect during the exposure process on the wafer surface.

Illustratively, the refractive index and extinction coefficient of the phase reversal layer 20, the protective layer 22 and the phase difference adjusting layer 21 included in the phase reversal layer 20 can be measured through NANO-VIEW's MG-PRO equipment. can

A thickness ratio of the protective layer 22 to the thickness 1 of the phase shift layer 20 may be 0.04 to 0.09. The thickness ratio may be 0.05 to 0.08. In this case, the protective layer 22 may stably protect the phase difference adjusting layer 21 .

The thickness of the passivation layer 22 may be 25 Å or more and 80 Å or less. The thickness of the passivation layer 22 may be 35 Å or more and 45 Å or less. In this case, it is possible to provide the phase reversal layer 20 that exhibits stable optical properties despite a plurality of exposure and cleaning processes while efficiently controlling the degree of change in optical properties on the entire phase reversal layer.

For example, the phase shift layer 20 and the thickness of each layer constituting the phase shift layer 20 may be confirmed through a TEM (Transmission Electron Microscopy) image of the cross section of the phase shift layer 20 .

Crystalline Characteristics of Phase Inversion Layer: Amorphous Index

Crystal characteristics of the phase shift layer may be similar to those of the transparent substrate.

When the phase shift layer and the transparent substrate are analyzed by X-ray diffraction (XRD) analysis, they may have similar crystal properties to each other.

Referring to FIG. 5 , the XRD analysis may be performed in a normal mode. The normal mode XRD analysis is θ-2θ mode. In the normal mode XRD analysis, X-rays are generated from the X-ray generator 60 and emitted to the sample 30 , and the X-rays reflected from the sample are detected through the detector 70 .

At this time, the X-ray generator 60 emits X-rays to the sample 30 at a predetermined incident angle θ. The angle of incidence θ is the angle between the direction of the X-ray from the X-ray generator and the horizontal plane of the sample. In addition, the X-ray generator emits X-rays to the sample while changing the incident angle θ.

The detector 70 is disposed on the opposite side to a location where the X-ray generator is disposed based on a location where the X-rays are incident on the sample. In addition, the detector detects X-rays having a predetermined emission angle θ among the X-rays reflected from the sample. The emission angle is the angle between the direction of the X-ray reflected from the sample and the horizontal plane of the sample.

In addition, the detector 70 is scanned corresponding to the scan direction of the X-ray generator. That is, when the X-ray generator is scanned, the detector is scanned so that the incident angle θ and the exit angle θ are equal to each other. In the normal mode XRD analysis, the X-ray generator and the detector may move on the same plane so that the incident angle and the emission angle are equal to each other. In addition, the X-ray generator may move so that a distance from a position where the X-rays are incident on the sample is constant. In addition, the detector may move so that a distance from a position where the X-rays are reflected from the sample is constant. That is, the X-ray generator and the detector may be moved while drawing an arc.

In the normal mode XRD analysis, an X-ray source may be a copper target. In addition, in the normal mode XRD analysis, the wavelength of the X-rays may be about 1.542 nm. In addition, in the normal mode XRD analysis, a voltage used to generate the X-rays may be about 45 kV. In addition, in the normal mode XRD analysis, the current used to generate the X-rays may be about 200 mA. In addition, in the normal mode XRD analysis, the measurement range of 2θ may be about 10° to about 100°. In addition, the normal mode XRD analysis can be performed every time a change of about 0.05 ° with respect to 2θ. In addition, in the normal mode XRD analysis, the scan speed of the X-ray generator and the detector may be about 5°/min.

In more detail, in the normal mode XRD analysis, the X-ray source is a copper target, the wavelength of the X-ray is about 1.542 nm, and the voltage used to generate the X-ray is about 45 kV, the current used to generate the X-ray is about 200 mA, the measurement range of 2θ is about 10° to about 100°, and the measurement is performed every time about 0.05° is changed based on 2θ, the X-ray generator and a scan rate of the detector may be about 5°/min.

In the photomask and/or the blank mask, the phase shift layer and the transparent substrate may have crystal properties similar to each other. A crystalline characteristic of the phase shift layer measured by the normal mode XRD analysis and a crystalline characteristic of the transparent substrate measured by the normal mode XRD analysis may be similar to each other.

When the normal mode XRD analysis is performed on the phase reversal layer, 2θ of the measured X-ray intensity after reflection has a maximum value between 15° and 30°, and the normal mode XRD analysis on the back (lower side) of the transparent substrate As it proceeds, 2θ of the measured X-ray intensity after reflection may have a maximum value between 15° and 30°.

Hereinafter, the XRD analysis performed in the phase reversal layer means that the XRD analysis of the photomask or the blank mask is performed on the phase reversal layer, and it is also expressed that the XRD analysis is performed in the direction of the phase reversal layer. Similarly, when the XRD analysis is performed on the transparent substrate, it means that the XRD analysis is performed on the rear surface of the transparent substrate, and it is also expressed that the XRD analysis is performed in the direction of the transparent substrate.

When normal mode XRD analysis is performed on the phase reversal layer, 2θ of the measured X-ray intensity after reflection has a maximum value between 20° and 25°, and when the normal mode XRD analysis is performed on the transparent substrate, after reflection 2θ of the measured X-ray intensity may have a maximum value between 20° and 25°.

In addition, when the normal mode XRD analysis is performed on the phase reversal layer, when the X-ray intensity measured after reflection is maximum 2θ and the normal mode XRD analysis is performed on the transparent substrate, the X-ray intensity measured after reflection is the maximum The difference of 2θ may be within 5°. In more detail, when the normal mode XRD analysis is performed on the phase reversal layer, when the X-ray intensity measured after reflection is maximum 2θ and the normal mode XRD analysis is performed on the transparent substrate, the measured X-ray intensity after reflection is the maximum The difference in 2θ may be within 3°. When the normal mode XRD analysis is performed on the phase reversal layer, the measured X-ray intensity after reflection is the maximum 2θ, and when the normal mode XRD analysis is performed on the transparent substrate, the measured X-ray intensity after reflection is the maximum 2θ. The difference may be within 1°.

In addition, in the photomask and/or the blank mask, the first amorphous index AI1 expressed by Equation 1 below may be 0.9 to 1.1.

[Equation 1]

Here, XM1 is the maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the phase reversal layer, and XQ1 is the X measured when the normal mode XRD analysis is performed on the lower surface of the transparent substrate It is the maximum value of the line strength.

The first amorphous index may be 0.95 to 1.05. The first amorphous index may be 0.97 to 1.03. The first amorphous index may be 0.98 to 1.02. The first amorphous index may be 0.99 to 1.01.

In addition, in the photomask and/or the blank mask, the third amorphous index AI3 expressed by Equation 3 below may be 0.9 to 1.1.

[Equation 3]

Here, AM1 is an area when 2θ is between 15° and 30° in the X-ray intensity measured after reflection when XRD analysis is performed on the phase reversal layer, where AQ1 is XRD analysis on the transparent substrate As it progresses, it is the area when 2θ is between 15° and 30° in the measured X-ray intensity after reflection.

The third amorphous index may be 0.95 to 1.05. The third amorphous index may be 0.97 to 1.03. The third amorphous index may be 0.98 to 1.02. The third amorphous index may be 0.99 to 1.01.

In addition, in the photomask and/or the blank mask, the fourth amorphous index AI4 expressed by Equation 4 below may be 0.9 to 1.1.

[Equation 4]

Here, XM4 is the X-ray intensity reflected when 2θ is 43° when the XRD analysis is performed on the phase reversal layer, and XQ4 is the X-ray intensity when the XRD analysis is performed on the lower surface of the transparent substrate, 2θ is 43° is the intensity of the reflected X-ray.

The fourth amorphous index may be 0.95 to 1.05. The fourth amorphous index may be 0.97 to 1.03. The fourth amorphous index may be 0.98 to 1.02. The fourth amorphous index may be 0.99 to 1.01.

Referring to FIG. 6 , the XRD analysis may be performed as a fixed mode XRD analysis. In the fixed mode XRD analysis, X-rays are generated from an X-ray generator and emitted to a sample, and X-rays reflected from the sample are detected through a detector.

In this case, in the fixed mode XRD analysis, the X-ray generator emits X-rays to the sample at a fixed incident angle (eg, 1°). The angle of incidence is the angle between the direction of the X-rays from the X-ray generator and the horizontal plane of the sample.

The detector is disposed on the opposite side to a location where the X-ray generator is disposed based on a location where the X-ray is incident on the sample. In addition, the detector detects X-rays having a predetermined emission angle θ among the X-rays reflected from the sample. The emission angle is the angle between the direction of the X-ray reflected from the sample and the horizontal plane of the sample.

In addition, the detector includes the X-ray generator and the location at which the X-rays are incident, and is scanned in a plane perpendicular to the horizontal plane of the sample. That is, the detector is scanned to detect X-rays emitted at various emission angles θ. In the fixed mode XRD analysis, the X-ray generator, the detector, and the site to be measured in the sample are arranged on the same plane. Also, on the same plane, the detector may move. In addition, the detector may be moved so that a distance from a position where the X-rays are reflected from the sample is constant. That is, the detector may be moved while drawing an arc.

In the fixed mode XRD analysis, the incident angle may be about 1°. In the fixed mode XRD analysis, an X-ray source may be a copper target. In addition, in the fixed mode XRD analysis, the wavelength of the X-rays may be about 1.542 nm. In addition, in the fixed mode XRD analysis, a voltage used to generate the X-rays may be about 45 kV. In addition, in the fixed mode XRD analysis, the current used to generate the X-rays may be about 200 mA. In addition, in the fixed mode XRD analysis, the range of 2θ of the detector may be about 10° to about 100°. In addition, the fixed-mode XRD analysis may be performed every time the 2θ changes by about 0.05°. In addition, in the fixed mode XRD analysis, the scan speed of the detector may be about 5°/min.

More specifically, in the fixed mode XRD analysis, the incident angle is about 1°, the X-ray source is a copper target (Cu target), the wavelength of the X-ray is about 1.542 nm, and the X-ray The voltage used to generate the X-ray is about 45 kV, the current used to generate the X-ray is about 200 mA, and the measurement range of 2θ is about 10° to about 100°, and every time it changes about 0.05° based on 2θ A measurement is performed, and the scan rate of the detector may be about 5°/min.

In the photomask and/or the blank mask, the phase shift layer and the transparent substrate may have crystal properties similar to each other. A crystalline characteristic of the phase shift layer measured by the fixed mode XRD analysis and a crystalline characteristic of the transparent substrate measured by the fixed mode XRD analysis may be similar to each other.

When the fixed mode XRD analysis is performed on the phase reversal layer, 2θ of the measured X-ray intensity after reflection has a first peak between 15° and 25°, and when the fixed-mode XRD analysis is performed on the transparent substrate, reflection After the measured X-ray intensity, 2θ may have a second peak between 15° and 25°.

2θ at the first peak may be between about 17° and about 23°, and 2θ at the second peak may be between about 17° and about 23°.

2θ at the first peak may be between about 19° and about 22°, and 2θ at the second peak may be between about 19° and about 22°.

A difference between 2θ at the first peak and 2θ at the second peak may be within about 5°. A difference between 2θ at the first peak and 2θ at the second peak may be within about 3°. A difference between 2θ at the first peak and 2θ at the second peak may be within about 2°.

In the photomask and/or the blank mask, the second amorphous index AI2 expressed by Equation 2 below may be about 0.9 to about 1.1.

[Equation 2]

Here, XM2 is the maximum value of the first peak, and XQ2 is the maximum value of the second peak.

The second amorphous index may be about 0.95 to about 1.05. The second amorphous index may be about 0.97 to about 1.03. The second amorphous index may be about 0.98 to about 1.02.

Manufacturing method of phase inversion layer

Among the phase reversal layers 20 of the embodiment, the phase difference control layer 21 may be manufactured by forming a thin film on the transparent substrate 10 through sputtering.

The sputtering process may use DC power or RF power.

The target and sputtering gas may be selected in consideration of the composition of the material constituting the thin film.

In the case of a sputtering target, one target containing a transition metal and silicon may be applied, and a target containing a transition metal and a target containing silicon may be applied respectively. When a target is applied as a sputtering target, the transition metal content relative to the sum of the transition metal and silicon contents of the target may be 30% or less. The transition metal content relative to the sum of the transition metal and silicon content of the target may be 20% or less. The transition metal content relative to the sum of the transition metal and silicon content of the target may be 10% or less. The transition metal content compared to the sum of the transition metal and silicon content of the target may be 2% or more. In this case, the phase reversal layer formed during sputtering by applying the target may have desired optical properties.

In the case of the sputtering gas, the sputtering gas may be prepared in consideration of a composition other than the composition contained in the target among the elements constituting the thin film. Specifically, CH ₄ as a gas containing carbon, O ₂ as a gas containing oxygen, N ₂ as a gas containing nitrogen, etc. may be introduced, but is not limited thereto. An inert gas may be added to the sputtering gas in addition to the gas containing the elements constituting the thin film. Examples of the inert gas include Ar, He, and the like, but are not limited thereto. Depending on the composition of the inert gas, the film quality of a thin film formed during sputtering may be changed. Therefore, it is possible to control the optical properties of the thin film by adjusting the composition of the inert gas. The sputtering gas may be introduced into the chamber for each gas having the same composition. The sputtering gas may be introduced into the chamber by mixing gases of each composition.

A magnet may be disposed in the chamber to improve the thickness of the thin film to be formed and the uniformity of in-plane optical properties. Specifically, by positioning the magnet on the back side of the sputtering target, and rotating the magnet at a speed of a certain size, plasma can be maintained at a constant distribution on the front surface of the target. The magnet can be rotated at a speed of 50 to 200 rpm.

The rotation speed of the magnet may be fixed at a constant speed during sputtering. The rotation speed of the magnet can be varied during sputtering. The rotational speed of the magnet can be increased from the initial rotational speed to a constant speed during sputtering.

The rotation speed of the magnet may be increased by 5 to 20 rpm per minute from the initial rotation speed during sputtering. The rotation speed of the magnet may be increased by 7 to 15 rpm per minute from the initial rotation speed during sputtering. In this case, the desired film quality in the thickness direction of the phase inversion layer can be easily controlled.

As described above, if the magnetic field of the magnet is adjusted, the density of plasma formed in the chamber may be adjusted to control the crystal characteristics of the phase inversion layer 20 to be formed. The magnetic field of the magnet applied during sputtering may be 25 to 60 mT. The magnetic field may be 30 to 50 mT. In this case, the phase shift layer 20 to be formed may have crystal characteristics similar to those of the transparent substrate in a lithography process to which exposure light of a short wavelength is applied.

In the sputtering process, the T/S distance, which is the distance between the target and the substrate, and the angle between the substrate and the target may be adjusted. T/S distance may be 240 to 260mm. In this case, the film-forming speed can be stably controlled, and the uniformity of in-plane optical properties of the thin film to be formed can be improved. The angle between the substrate and the target may be 20 to 30 degrees. In this case, it is possible to suppress an excessive increase in the internal stress of the thin film to be formed.

In the sputtering process, the rotation speed of the substrate to be formed may be adjusted. The rotation speed of the substrate to be formed may be 2 to 20 RPM. The rotation speed of the substrate may be 5 to 15 RPM. When the rotation speed of the substrate to be formed is adjusted within this range, the phase reversal layer 20 formed into a film may have stable durability while the degree of equalization of optical properties in the in-plane direction is further improved.

In addition, it is possible to adjust the intensity of the voltage applied to the sputtering target when the phase difference control layer 21 is formed. A discharge region including a plasma atmosphere in the chamber is formed by supplying a voltage to a target located in the sputtering chamber. By controlling the intensity of the voltage, the quality of a film formed during sputtering can be controlled by controlling the plasma atmosphere in the chamber together with the magnet. The strength of the voltage applied to the sputtering target may be 1 to 3 kW. The strength of the voltage may be 1.5 to 2.5 kW. The strength of the voltage may be 1.8 to 2.2 kW. In this case, the thermal fluctuation in the thickness direction according to the temperature of the phase reversal layer 20 may be controlled within a certain range.

A spectral ellipse analyzer can be installed in the sputtering equipment. Through this, the deposition time can be controlled so that the retardation control layer 21 to be formed can have desired optical properties. Specifically, after setting the angle θ formed by the incident light (L _i ) with the surface of the phase difference control layer 21 formed into a film, the Del value of the phase difference control layer 21 formed in real time during the deposition process can be monitored. have. By proceeding the deposition process until the Del value falls within the set range, the phase inversion layer 20 may have desired optical properties.

By measuring the phase difference between the P and S waves of the reflected light while changing the photon energy of the incident light of the spectral elliptic analyzer, the optical properties of each layer of the thin film to be measured can be measured. Specifically, when the photon energy of the incident light is relatively low, the incident light forms a long wavelength, so that the optical characteristics of the lower layer of the measurement target thin film can be measured. When the photon energy of the incident light is relatively high, the incident light forms a short wavelength, so that the optical characteristics of the upper layer of the measurement target thin film can be measured.

Exemplarily, the phase reversal layer has a photon energy of 1.8 to 2.15 eV at a point where the Del_1 value is 0 according to Equation A below, measured by a spectral elliptic analyzer by applying an incident angle of 64.5°.

[Formula A]

In Equation A, the DPSp value is the phase difference between the P-wave and the S-wave if the phase difference between the P-wave and the S-wave of the reflected light is 180° or less when the phase inversion layer is measured with a spectral elliptic analyzer by applying an incident angle of 64.5° , when the phase difference between the P-wave and the S-wave of the reflected light exceeds 180°, it is a value obtained by subtracting the phase difference between the P-wave and the S-wave from 360°.

The PE value is a photon energy within a range of 1.5 to 3.0 eV, when PE ₁ is 1.5 eV and PE ₂ is 3 eV.

Immediately after the sputtering process is finished, the surface of the retardation control layer 21 may be irradiated with a UV light source. In the sputtering process, Si of the SiO ₂ matrix constituting the transparent substrate 10 may be substituted with a transition metal, and O may be substituted with N. If the sputtering process is continued, the transition metal is out of the Solubility Limit and is placed in an interstitial site rather than being substituted with Si in the SiO ₂ matrix, so that the transition metal is an element such as Si, O, N can form a mixture with The mixture may be in a homogeneous state or an inhomogeneous state.

In the case of the phase difference control layer 21 having a non-uniform mixture formed on the surface, a haze defect may be formed on the surface of the phase difference control layer 21 by exposure light having a short wavelength during the exposure process. In addition, when sulfuric acid is used as a cleaning liquid in the cleaning process for removing defects, sulfur ions may remain on the surface of the retardation control layer 21 after the cleaning process. Residual sulfur ions may react with a non-uniform mixture when receiving strong energy from exposure light during the wafer exposure process for a long period of time to generate growth defects on the surface of the phase difference control layer 21 . Therefore, by exposing UV light of a preset wavelength to the surface of the phase difference control layer 21 to equalize the transition metal and N content in the mixture of the surface of the phase difference control layer 21 in the direction of the film, the light resistance and resistance of the phase difference control layer 21 It can improve drug properties.

The surface treatment of the phase difference control layer 21 using UV light may be performed by exposing a light source having a wavelength of 200 nm or less to the phase difference control layer 21 at a power of 2 to 10 mW/cm ² for 5 to 20 minutes.

The phase difference control layer 21 may be heat-treated together with or separately from the UV light irradiation process. The UV light irradiation process and heat treatment may be applied by utilizing the heat generated by UV irradiation, or may be performed as a separate process.

The phase difference control layer 21 after the deposition through the sputtering process may have an internal stress. The internal stress may be a compressive stress or a tensile stress depending on the conditions of sputtering. The internal stress of the phase difference control layer 21 may cause warpage of the substrate, which may cause a decrease in resolution of a photomask manufactured using the blank mask 100 . When heat treatment is performed on the phase difference control layer 21 , the internal stress of the phase shift layer 20 is reduced, thereby reducing the warpage of the substrate.

The protective layer 22 may be formed on the phase difference adjusting layer 21 through a separate sputtering process. The protective layer 22 may be formed by performing a surface treatment process on the retardation adjusting layer 21 after forming the retardation adjusting layer 21 .

The protective layer 22 may be formed through a heat treatment process after forming the retardation adjusting layer 21 through sputtering. During the heat treatment process, the protective layer 22 may be formed by reacting the surface of the phase difference adjusting layer 21 with the atmospheric gas. However, the method of manufacturing the protective layer 22 is not limited thereto.

The protective layer 22 may be formed on the surface of the retardation control layer 21 by introducing an atmospheric gas in the chamber during the heat treatment process. Atmospheric gas may be introduced during the heat treatment process. The atmospheric gas includes He, Ar, and the like, but is not limited thereto.

The heat treatment process may include a temperature raising step, a temperature maintaining step, a temperature decreasing step, and a protective layer forming step. The heat treatment process may be performed by disposing a blank mask having a phase difference control layer 21 formed thereon in a chamber and then heating it through a lamp.

The temperature raising step is a step of raising the temperature in the chamber from room temperature to a set temperature of 150 to 500°C. The temperature maintaining step is a step of maintaining the temperature in the chamber at the set temperature and maintaining the pressure in the chamber at 0.1 to 2.0 Pa. The temperature maintaining step may be performed for 5 to 60 minutes. The temperature lowering step is a step of lowering the temperature in the chamber from the set temperature to room temperature. The protective layer forming step is a step of forming a protective layer on the surface of the phase reversal layer by introducing a gas containing a reactive gas into the chamber after the temperature lowering step is completed. The reactive gas may include O ₂ . The gas introduced into the chamber in the protective layer forming step may include at least one of N ₂ , Ar, and He. Specifically, in the protective layer forming step, O ₂ gas may be introduced into the chamber at 0.3 to 2.5 SLM (Standard Liter per Minute). The O ₂ gas may be introduced into the chamber at 0.5 to 2 SLM. The protective layer forming step may proceed for 10 to 60 minutes. The protective layer forming step may proceed for 12 to 45 minutes. In this case, the content of each element in the thickness direction of the protective layer 22 may be adjusted to suppress the optical characteristic variation of the phase reversal layer 20 due to the protective layer 22 .

The Del_2 value distribution was measured when PE ₁ was 1.5 eV and PE ₂ was 5.0 eV using a spectral elliptic analyzer (manufactured by Nano-View, Inc. MG-PRO). Specifically, after setting the angle of incident light to 64.5 with respect to the surface of the phase shift film on which the film formation has been completed for each Example and Comparative Example, the phase difference between P and S waves according to photon energy was measured and converted into a Del_2 value.

In the blank mask 100 , when the PE ₁ value is 3.0 eV and the PE ₂ value is 5.0 eV, the photon energy at the point where Del_2 is 0 expressed by Equation B below may be 3.9 to 4.7 eV.

[Formula B]

In Equation B, the DPS value is, when the phase shift film surface is measured with a spectral ellipsometer by applying an incident angle of 64.5° on the protective layer, if the phase difference between the P wave and the S wave of the reflected light is 180° or less, the P wave and a phase difference between the S waves. If the phase difference between the P wave and the S wave of the reflected light exceeds 180°, it is a value obtained by subtracting the phase difference between the P wave and the S wave from 360°.

The PE value is a photon energy within the range of PE ₁ to PE ₂ .

shading layer

The light blocking layer 30 may have a single-layer structure. The light blocking layer 30 may have a multi-layer structure of two or more layers. The light blocking layer 30 may be formed through sputtering. The light blocking layer 30 may have a layer structure of two or more layers according to sputtering control conditions. Light-shielding layer 30 In the sputtering process, a plurality of light-shielding layers 30 may be formed by changing the flow rate of each atmospheric gas for each layer. Light blocking layer 30 During the sputtering process, a plurality of light blocking layers 30 may be formed by changing the sputtering target for each layer.

The light blocking layer 30 may include chromium and nitrogen. The light blocking layer 30 may include chromium, oxygen, nitrogen, and carbon. The content of each element relative to the entire light blocking layer 30 may be different in the thickness direction. The content of each element relative to the total light blocking layer 30 may be different for each layer in the case of the plurality of light blocking layers 30 .

The light blocking layer 30 may include 44 to 60 atomic % of chromium. The light blocking layer 30 may include 47 to 57 atomic % of chromium. The light blocking layer 30 may contain 5 to 30 atomic % of carbon. The light blocking layer 30 may contain 7 to 25 atomic % carbon. The light blocking layer 30 may contain 3 to 20 atomic % nitrogen. The light blocking layer 30 may contain 5 to 15 atomic % nitrogen. The light blocking layer 30 may contain 20 to 45 atomic % oxygen. The light blocking layer 30 may contain 25 to 40 atomic % oxygen. In this case, the light blocking layer 30 may have sufficient quenching characteristics by adjusting the thickness, and may be induced to have appropriate etching characteristics.

The phase shift layer and the light blocking layer may be combined to form a multilayer. That is, the multilayer (not shown) includes a phase inversion layer 20 and a light blocking layer 30 . The multilayer may form a blind pattern on the transparent substrate 10 to suppress transmission of the exposure light.

The optical density of the multilayer with respect to light having a wavelength of 200 nm or less may be 3 or more. The optical density for ArF light of the multilayer may be 3 or more. The optical density of the multilayer for light having a wavelength of 200 nm or less may be 3.5 or more. The optical density of the multilayer for ArF light may be 3.5 or more. In this case, the multilayer may have excellent light blocking properties.

Crystalline properties of light-shielding layer: amorphous index

The light blocking layer has a different crystal characteristic from that of the transparent substrate. The crystal properties of the light blocking layer and the crystal properties of the transparent substrate may be different from each other. An XRD analysis result of the light blocking layer and an XRD analysis result of the transparent substrate may be different from each other. A normal mode XRD analysis result of the light blocking layer may be different from a normal mode XRD analysis result of the transparent substrate. A fixed mode XRD analysis result of the light blocking layer may be different from a fixed mode XRD analysis result of the transparent substrate.

When the normal mode XRD analysis is performed through the light shielding layer, 2θ of the measured X-ray intensity after reflection has a maximum value between 15° and 30°, and through the lower surface of the transparent substrate, the normal mode XRD analysis During this process, 2θ of the measured X-ray intensity after reflection may have a maximum value between 15° and 30°.

In this case, in the photomask and the blank mask, the fifth amorphous index AI5 expressed by Equation 5 below may be 0.5 to 0.97.

[Equation 5]

Here, XC1 is the maximum value of the X-ray intensity measured by the normal mode XRD analysis through the light blocking layer, and XQ1 is the X-ray intensity measured by the normal mode XRD analysis through the lower surface of the transparent substrate. is the maximum

The fifth amorphous index may be 0.7 to 0.97. The fifth amorphous index may be 0.5 to 0.95. The fifth amorphous index may be 0.7 to 0.95. The fifth amorphous index may be 0.7 to 0.93. The fifth amorphous index may be 0.9 to 0.93.

In the photomask and the blank mask, a sixth amorphous index AI6 expressed by Equation 6 below may be 1.05 to 1.4.

[Equation 6]

Here, XM4 is the X-ray intensity measured when 2θ is 43° when the normal mode XRD analysis is performed on the light blocking layer, and XQ4 is the normal mode XRD analysis on the lower surface of the transparent substrate. When 2θ is 43°, it is the measured X-ray intensity.

The sixth amorphous index may be 1.06 to 1.4. The sixth amorphous index may be 1.07 to 1.4. The sixth amorphous index may be 1.08 to 1.4.

The light blocking layer of the embodiment may be formed in contact with the phase reversal layer, and may be formed in contact with another thin film positioned on the phase reversal layer.

The light blocking layer may include a lower layer and an upper layer positioned on the lower layer.

The sputtering process may use DC power or RF power.

In consideration of the composition of the light blocking layer, a target and a sputtering gas may be selected during sputtering of the light blocking layer. When the light-shielding layer includes two or more layers, the composition of the sputtering gas may be differently applied during sputtering for each layer. When the light-shielding layer includes two or more layers, the composition of the sputtering target and the sputtering gas may be differently applied during sputtering for each layer.

In the case of a sputtering target, one target containing chromium may be applied, and two or more targets including one target containing chromium may be applied. The target containing chromium may contain 90 atomic% or more of chromium. The target containing chromium may contain 95 atomic% or more of chromium. The target containing chromium may contain 99 atomic% or more of chromium.

In the case of the sputtering gas, the composition of the sputtering gas may be adjusted in consideration of the composition of elements constituting each layer of the light-shielding layer, film quality of the light-shielding layer, optical characteristics, and the like.

The sputtering gas may include a reactive gas and an inert gas. By controlling the content of the reactive gas in the sputtering gas, it is possible to control the optical properties and film quality of the light-shielding layer to be formed. Reactive gases are CO ₂ , O ₂ , N ₂ and NO ₂ and the like. The reactive gas may further include other gases in addition to the gases described above.

By controlling the content of the inert gas in the sputtering gas, the film quality of the light-shielding layer to be formed can be controlled. The inert gas may include Ar, He, Ne, and the like. The inert gas may further include other gases in addition to the gases described above.

When forming the lower layer of the light blocking layer, a sputtering gas containing Ar, N2, He, and CO ₂ may be injected into the chamber. Specifically, the sum of the flow rates of CO ₂ and N ₂ relative to the total flow rate of the sputtering gas may be 40% or more of the sputtering gas may be injected into the chamber. In this case, the lower layer of the light blocking layer may have desired crystal properties. Accordingly, the photomask and the blank mask may have the fifth amorphous index and the sixth amorphous index.

When forming the upper layer of the light blocking layer, a sputtering gas containing Ar and N ₂ may be injected into the chamber. Specifically, a sputtering gas having a flow rate of 30% or more of N ₂ relative to the total flow rate of the sputtering gas may be injected into the chamber. In this case, the upper layer of the light blocking layer may have a desired crystal property. Accordingly, the photomask and the blank mask may have the fifth amorphous index and the sixth amorphous index.

Each gas constituting the sputtering gas may be mixed and injected into the sputtering chamber. Each gas constituting the sputtering gas may be individually injected through different inlets in the sputtering chamber.

A magnet may be disposed in the chamber to control the film quality of the light blocking layer to be formed and the uniformity of in-plane optical properties. Specifically, by positioning the magnet on the back side of the sputtering target, and rotating the magnet at a speed of a certain size, plasma can be maintained at a constant distribution on the front surface of the target. The magnet may be rotated at a speed of 50 to 200 rpm when forming a film for each layer.

In the sputtering process, the T/S distance, which is the distance between the target and the substrate, and the angle between the substrate and the target may be adjusted. When forming each layer of the light blocking layer, the T/S distance may be 240 to 300 mm. In this case, the film-forming speed can be stably controlled, and the uniformity of in-plane optical properties of the thin film to be formed can be improved. The angle between the substrate and the target may be 20 to 30 degrees. In this case, it is possible to suppress an excessive increase in the internal stress of the thin film to be formed.

In the sputtering process, the rotation speed of the substrate to be formed may be adjusted. When forming each layer of the light blocking layer, the rotation speed of the substrate to be formed may be 2 to 50 RPM. The rotation speed of the substrate may be 10 to 40 RPM. When the rotation speed of the substrate to be formed is adjusted within this range, the light blocking layer may have a desired crystal property. Accordingly, the photomask and the blank mask may have the fifth amorphous index and the sixth amorphous index.

In addition, it is possible to adjust the intensity of the voltage applied to the sputtering target when the light blocking layer 30 is formed. A discharge region including a plasma atmosphere in the chamber is formed by supplying a voltage to a target located in the sputtering chamber. By controlling the intensity of the voltage, the quality of a film formed during sputtering can be controlled by controlling the plasma atmosphere in the chamber together with the magnet.

The intensity of the voltage applied to the sputtering target during the formation of the lower layer of the light blocking layer may be 0.5 to 2 kW. The strength of the voltage may be 1.0 to 1.8 kW. The strength of the voltage may be 1.2 to 1.5 kW. The intensity of the voltage applied to the sputtering target during the formation of the upper layer of the light blocking layer may be 1 to 3 kW. The strength of the voltage may be 1.3 to 2.5 kW. The strength of the voltage may be 1.5 to 2.0 kW. In this case, the lower layer of the light blocking layer may have desired crystal properties. Accordingly, the photomask and the blank mask may have the fifth amorphous index and the sixth amorphous index.

A spectral ellipse analyzer can be installed in the sputtering equipment. Through this, the film formation time can be controlled so that the light blocking layer 30 formed into a film can have a desired optical characteristic. When the light blocking layer 30 is formed, the method of measuring after installing the spectral elliptic analyzer in the sputtering equipment is the same as that in the formation of the phase reversal layer, so it is omitted.

When forming the lower layer of the light shielding layer 30, sputtering may be performed until the photon energy at the point where the phase difference between the P wave and the S wave of the reflected light measured by a spectral elliptic analyzer is 140° becomes 1.6 to 2.2 eV. When forming the lower layer of the light shielding layer 30, sputtering may be performed until the photon energy at the point where the phase difference between the P wave and the S wave of the reflected light measured by a spectral elliptic analyzer is 140° becomes 1.8 to 2.0 eV.

When the upper layer of the light blocking layer 30 is formed, sputtering may be performed until the photon energy at the point where the phase difference between the P wave and the S wave of the reflected light measured by a spectral elliptic analyzer is 140° becomes 1.7 to 3.2 eV. When the upper layer of the light blocking layer 30 is formed, sputtering may be performed until the photon energy at the point where the phase difference between the P wave and the S wave of the reflected light measured by a spectral elliptic analyzer is 140° becomes 2.5 to 3.0 eV.

As described above, the light blocking layer and the transparent substrate have different crystal characteristics. Accordingly, the light blocking layer and the transparent substrate may have different optical properties. Accordingly, the light blocking layer may have a high optical density.

In this case, the formed light blocking layer may be included in the blind pattern of the photomask to effectively block the exposure light.

photomask manufacturing

A photomask according to another exemplary embodiment may be manufactured using the blank mask 100 described above.

Specifically, the photomask may be dried to form a resist film (not shown) after coating the surface of the blank mask 100 with a resist. The resist may be a positive resist or a negative resist. The resist film may be formed adjacent to the light blocking layer 30 . A resist film may be formed adjacent to the surface of another film positioned on the light blocking layer 30 .

A pattern can be formed by drawing a pattern on the resist film through EB or light irradiation, then heating and developing. The thin film formed on the surface of the blank mask 100 may be etched using the formed resist pattern as an etching mask. The thin film to be etched may be the light blocking layer 30 . The thin film to be etched may be another thin film formed on the light blocking layer 30 . In the etching process, dry etching may be applied depending on the composition of the film to be etched. As the etching gas applied to the dry etching, chlorine-based gas and fluorine-based gas may be applied.

Thereafter, the resist film may be removed, and the phase shift layer and the light blocking layer may be etched according to a designed pattern shape. During etching, different etchants may be applied in consideration of the etching characteristics of each thin film.

Since the first amorphous index has the above range, the phase shift layer and the transparent substrate have very similar crystal properties.

In addition, since the second amorphous index has the above range, the phase shift layer and the transparent substrate have very similar crystal properties.

In addition, since the third amorphous index has the above range, the phase shift layer and the transparent substrate have very similar crystal properties.

In addition, since the fourth amorphous index has the above range, the phase shift layer and the transparent substrate have very similar crystal properties.

Accordingly, optical distortion due to a difference in crystal characteristics between the phase shift layer and the transparent substrate may be minimized. In addition, it is easier to control the difference in the degree of etching caused by the difference in crystal characteristics. That is, since the phase shift layer and the transparent substrate have similar crystal properties according to XRD analysis, the photomask may have improved optical performance.

In particular, since the transparent substrate and the phase shift layer have similar crystal properties, optical distortion generated at the interface between the transparent substrate and the phase shift layer is reduced when the transparent substrate and the phase shift layer are in direct contact with each other. can be

In addition, since the fifth amorphous index has the above range, the light blocking layer and the transparent substrate have different crystal properties.

Since the sixth amorphous index has the above range, the light blocking layer and the transparent substrate have different crystal properties.

Accordingly, the light blocking layer may have improved light blocking performance.

Accordingly, the apparatus for manufacturing a semiconductor device according to the embodiment may reduce process errors due to optical distortion in exposure and development processes. Accordingly, the apparatus for manufacturing a semiconductor device according to the embodiment can easily manufacture a semiconductor device having improved fine line width characteristics.

Hereinafter, specific examples will be described in more detail.

Preparation example: film formation of a phase reversal layer and a light-shielding layer

Example 1: A quartz transparent substrate having a width of 6 inches, a length of 6 inches, and a thickness of 0.25 inches was disposed in the chamber of the DC sputtering equipment. A target containing molybdenum and silicon in an atomic ratio of 1:9 was placed in the chamber so that the T/S distance was 255 mm and the angle between the substrate and the target was 25 degrees. A magnet having a magnetic field of 40 mT was placed on the back surface of the target.

After that, a sputtering gas mixed in a ratio of Ar:N ₂ :He=10:52:38 was introduced into the chamber, the sputtering voltage was 2.05kW, and the sputtering process was performed while rotating the magnet. At this time, the rotation speed of the magnet was increased from the initial 100 rpm to a maximum of 155 rpm by 11 rpm per minute. The area where the thin film was formed was limited to the area set by the width of 132 mm and the length of 132 mm on the surface of the transparent substrate. The sputtering process was performed until the photon energy at the point where the Del_1 value was 0 according to Equation A below measured with a spectral ellipse analyzer at an incident angle of 64.5° became 2.0eV.

[Formula A]

In Equation A, the DPS value means the phase difference between the P wave and the S wave when the phase difference between the P wave and the S wave of the reflected light is 180° or less, and when the phase difference between the P wave and the S wave of the reflected light exceeds 180°, at 360° It means a value obtained by subtracting the phase difference between the P wave and the S wave.

After sputtering, the surface of the phase shift layer of the blank mask was exposed to Excimer UV light with a wavelength of 172 nm. At this time, the output of the UV light was increased to a maximum of 9mW/cm ² by 3mW/cm ² per minute, and was maintained at 9mW/cm ² power for 4 minutes.

Thereafter, the blank mask was introduced into a chamber for a heat treatment process, annealed at 1 Pa, and then cooled naturally. The temperature in the annealing process was increased from room temperature to a maximum of 400° C. at a rate of 50° C. per minute, and was maintained at the maximum temperature for about 30 minutes. After natural cooling, O ₂ gas in the chamber for the heat treatment process was introduced into the chamber at a rate of 1 SLM for 30 minutes. At this time, the supply temperature of O ₂ was about 300 ℃.

A light-shielding layer sputtering process was performed on the surface of the phase shift layer formed into a film. Specifically, the T/S distance in the sputtering chamber was 255 mm, and the transparent substrate on which the chromium target and the phase inversion layer were formed was disposed so that the angle between the substrate and the target was 25 degrees. A magnet having a magnetic field of 40 mT was placed on the back surface of the target.

A sputter gas having a flow ratio in the chamber of Ar:N ₂ :He:CO ₂ =19:11:34:37 was injected. After that, the sputtering voltage is applied to 1.35kW, and the photon energy at the point where the phase difference between the P wave and the S wave measured with a spectral ellipse analyzer is 140° while rotating the magnet is 1.8 to 2.0 eV. filmed. A sputtering process was performed. At this time, the rotation speed of the magnet was increased from the initial 100 rpm to a maximum of 155 rpm by 11 rpm per minute.

After the light-shielding layer lower layer was formed, a sputtering gas having an in-chamber flow ratio of Ar:N ₂ =57:43 was injected. After that, the sputtering voltage was applied to 1.85 kW and the magnet was rotated. Sputtering was carried out until the photon energy at the point where the phase difference between the P wave and the S wave measured with a spectral ellipticity analyzer became 2.75 to 2.95 eV at a point of 140° to form an upper layer of the light shielding layer.

A total of two samples were prepared by applying the film-forming conditions as described above.

Example 2: The sputtering process was performed under the same conditions as in Example 1, but the magnet magnetic force was applied as 45 mT, and the process progress time was determined when the photon energy at the point where the Del_1 value according to Equation A is 0 is 1.89 eV. was carried out until

Example 3: A sputtering process was performed under the same conditions as in Example 1, except that the composition of the sputtering gas was changed to a ratio of Ar:N ₂ :He=8:58:34.

Comparative Example 1: A quartz transparent substrate having a width of 6 inches, a length of 6 inches, and a thickness of 0.25 inches was disposed in the chamber of the DC sputtering equipment. A target containing molybdenum and silicon in an atomic ratio of 1:9 was placed in the chamber so that the T/S distance was 255 mm and the angle between the substrate and the target was 25 degrees. A magnet having a magnetic field of 60 mT was placed on the rear surface of the target.

After that, a sputtering gas mixed in a ratio of Ar:N ₂ :He=9:52:39 was introduced into the chamber, the sputtering voltage was 2kW, and the magnet was rotated at a speed of 100rpm, and a sputtering process was performed. The area where the thin film was formed was limited to the area set by the width of 132 mm and the length of 132 mm on the surface of the transparent substrate. The sputtering process was performed until the photon energy at the point where the Del_1 value according to Equation A was 0 became 2.0 eV. After film formation, UV light treatment and annealing treatment were not applied.

A light-shielding layer sputtering process was performed on the surface of the phase shift layer formed into a film. Specifically, the T/S distance in the sputtering chamber was 255 mm, and the transparent substrate on which the chromium target and the phase inversion layer were formed was disposed so that the angle between the substrate and the target was 25 degrees. A magnet having a magnetic field of 60 mT was placed on the rear surface of the target.

A sputter gas having a flow ratio in the chamber of Ar:N ₂ :He:CO ₂ =19:11:34:37 was injected. After that, the sputtering voltage is applied at 1.35 kW, and the photon energy at the point where the phase difference between the P wave and the S wave measured with a spectral ellipse analyzer is 140° while rotating the magnet at 100 rpm is 1.8 to 2.0 eV until the light is blocked by sputtering. The lower layer was formed into a film. A sputtering process was performed.

After the light-shielding layer underlayer was formed, a sputtering gas having an in-chamber flow rate ratio of Ar:N2=57:43 was injected. After that, the sputtering voltage was applied to 1.85 kW and the magnet was rotated. Sputtering was carried out until the photon energy at the point where the phase difference between the P wave and the S wave measured with a spectral ellipticity analyzer became 2.75 to 2.95 eV at a point of 140° to form an upper layer of the light shielding layer.

Comparative Example 2: A sputtering process was performed under the same conditions as in Comparative Example 1, but a magnet magnetic force of 20 mT was applied. In addition, no additional heat treatment process was applied.

Before forming the light blocking layer, the samples were measured for Del_2 value distribution when PE ₁ was 1.5 eV and PE ₂ was 5.0 eV using a spectral elliptic analyzer (manufactured by MG-PRO, Nano-View) installed in a sputtering device. . Specifically, after setting the angle of incident light to 64.5 with respect to the surface of the phase shift film on which the film formation has been completed in each of Examples and Comparative Examples, the phase difference between P and S waves according to photon energy is measured and converted to a Del_2 value according to Equation B did. The results are shown in Table 2 below.

Evaluation example: XRD analysis

In the blank masks prepared in Examples 1 to 3, Comparative Examples 1 and 2, normal mode XRD analysis and fixed mode XRD analysis were performed through the lower surface of the transparent substrate. In addition, in the blank mask, a normal mode XRD analysis and a fixed mode XRD analysis were performed through the light blocking layer. Thereafter, the light blocking layer included in the blank mask was removed by etching and cleaning processes, and the phase shift layer was exposed.

As described above, normal mode XRD analysis and fixed mode XRD analysis were performed through the exposed phase inversion layer.

The normal mode XRD analysis was performed under the following conditions.

Equipment name: Rigaku smartlab

x-ray source: Cu target

x-ray information: wavelength 1.542 nm, 45 kV, 200 mA

(Θ-2Θ) measurement range: 10~100 ˚

Step: 0.05 ˚

Speed : 5 ˚/min

The fixed mode XRD analysis was performed under the following conditions.

Equipment name: Rigaku smartlab

x-ray source: Cu target

x-ray information: wavelength 1.542 nm, 45 kV, 200 mA

X-ray generator exit angle: 1°

(Θ-2Θ) measurement range: 10~100 ˚

Step: 0.05 ˚

Speed : 5 ˚/min

Evaluation example: phase difference, transmittance measurement

For the examples and specimens described through the previous preparation examples, the light-shielding layer was removed by etching in the same manner as in the measurement of thermal fluctuations. The phase difference and transmittance were measured using a phase difference/transmittance measuring instrument (MPM193 manufactured by Lasertec). Specifically, by using an ArF light source (wavelength 193 nm) to irradiate light to the region where the phase shift layer is formed and the region where the phase shift layer is not formed of each specimen, the phase difference and transmittance difference value between the light passing through both regions was calculated and shown in Table 2 below.

Evaluation Example: Contrast and CD value measurement

After forming a photoresist film on the surface of the phase reversal layer of each specimen in Examples and Comparative Examples, a dense rectangular pattern was exposed on the surface of the photoresist film using Nuflare's EBM 9000 model. The target CD value of the rectangular pattern was set to 400 nm (4X). After the pattern was developed on the photoresist film of each specimen, the light blocking layer and the phase inversion layer were etched according to the developed pattern shape using the Tetra X model of Applied Materials. Thereafter, the photoresist pattern was removed.

The contrast and normalized CD value of the developed pattern during the wafer exposure process according to the Del_1 and Del_2 values of the phase inversion layer using the AIMS 32 model of Carl Zeiss for the specimens for each Example and Comparative Example including the phase inversion layer pattern was measured and calculated. For measurement and calculation, the numerical aperture (NA) was set to 1.35, the illumination system was set to crosspole 30X, outer sigma 0.8, and in/out sigma ratio 85%. The measured data are shown in Table 3 below.

AI1 AI2 AI3 AI4 AI5 AI6 Example 1 1.00 1.02 1.01 0.99 0.96 1.0938 Example 2 1.01 1.02 1.02 0.99 0.95 1.10 Example 3 1.00 1.03 1.02 1.00 0.93 1.11 Comparative Example 1 0.97 0.96 0.94 1.05 0.99 1.05 Comparative Example 2 0.94 0.95 0.93 1.02 0.98 1.05

magnetic field (mT) Photon energy (eV) at the point where Del_1 is 0 Photon energy (eV) at the point where Del_2 value is 0 Transmittance (%) Phase difference (°) Example 1 40 2.00 4.44 6.1 178.5 Example 2 45 1.89 4.31 5.4 186.1 Example 3 35 2.09 4.65 6.9 172.4 Comparative Example 1 60 1.65 3.84 3.4 209.1 Comparative Example 2 20 2.17 4.80 7.8 166.0

Normalized Contrast Normalized CD (nm) Example 1 1.000 0.99 Example 2 0.989 1.01 Example 3 0.959 1.03 Comparative Example 1 0.929 1.06 Comparative Example 2 0.883 1.10

In Table 1, the TFT1 and TFT2 values for each measurement condition of Examples 1 to 3 all showed a value of 0.25 um/100° C. or less, but the TFT1 and TFT2 values for each measurement condition of Comparative Examples 1 and 2 were all Values greater than 0.25 um/100°C were shown. This indicates that the thermal fluctuation of the thin film included in the blank mask can be controlled by controlling the process conditions and the like during sputtering.

In Table 2, Examples 1 to 3 in which the magnetic field was applied within the range of 30 to 50 mT, although the photon energy at the point where the Del_1 value is 0 is included in the range of 1.8 to 2.15 eV, Comparative Example 1 in which the magnetic field is less than 30 mT or more than 50 mT and 2 indicate that the photon energy at the point where the Del_1 value is 0 is not included in the range of 1.8 to 2.15 eV. Through this, it can be seen that the distribution of the Del_1 value according to the photon energy of the phase reversal layer can be controlled by adjusting the magnetic force of the magnet in the sputtering process.

In addition, in Examples 1 to 3 in which the additional heat treatment process was performed after film formation, the photon energy at the point where the Del_2 value is 0 was included in the range of 4 to 4.75 eV, but Comparative Examples 1 and 2 in which the additional heat treatment process was not performed after the film formation were It was found that the photon energy at the point where the Del_2 value is 0 is less than 4 or more than 4.75. This means that the distribution of Del_2 values according to the photon energy of the phase shift layer can be controlled by applying a heat treatment process after sputtering.

The transmittance of Examples 1 to 3 was within the range of 5.4 to 6.9%, and the retardation was within the range of 170 to 190°, but Comparative Example 1 had a transmittance of less than 4% and a retardation of 200° or more, and Comparative Example 2 was measured to have a transmittance of 7.5% or more and a phase difference of less than 170°. Through this, the phase inversion layer whose photon energy at the point where the Del_1 value is 0 and the photon energy at the point where the Del_2 value is 0 is adjusted within the set range has the desired transmittance (6%) and phase difference for exposure light with a short wavelength. It can be seen that the optical characteristic is close to (180 degrees).

In Table 3, Examples 1 to 3 in which the photon energy at the point where the Del_1 value is 0 falls within the range of 1.8 to 2.15 eV and the photon energy at the point where the Del_2 value is 0 falls within the range of 4 to 4.75 eV are normalized. Contrast 0.95 or more and the normalized CD value showed 1.03 or less, whereas Comparative Examples 1 and 2 showed less than 0.93 normalized contrast, and the normalized CD value showed 1.06 or more. Through this, the thermal fluctuation is controlled, and the phase inversion layer whose photon energy at the point where the Del_1 value is 0 and the photon energy at the point where the Del_2 value is 0 is adjusted within the set range achieves a higher level of resolution during pattern exposure. know that you have

Although the preferred embodiment has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the embodiment defined in the following claims are also within the scope of the present invention. will belong

100: blank mask 200: photo mask
10: transparent substrate
20: phase reversal layer 21: phase difference adjusting layer 22: protective layer
30: light shield
60: X-ray generator (light source)
70: detector

Claims (12)

light source; and
and a photomask to which the light from the light source is incident, selectively transmits the incident light, and exits to the semiconductor wafer,
The photo mask may include a transparent substrate; a phase inversion layer disposed on the transparent substrate; and a light blocking layer disposed on the phase inversion layer,
The transparent substrate is a synthetic quartz substrate is applied,
The phase reversal layer includes a retardation adjusting layer positioned on the transparent substrate and a protective layer positioned on the retardation adjusting layer,
The phase shift layer includes a transition metal, silicon, oxygen and nitrogen,
The phase difference adjusting layer contains 3 to 10 atomic % of a transition metal, 20 to 50 atomic % of silicon, 2 to 10 atomic % of oxygen, and 40 to 60 atomic % of nitrogen,
The protective layer contains 0.5 to 5 atomic % of a transition metal, 10 to 50 atomic % of silicon, 10 to 50 atomic % of oxygen, and 20 to 40 atomic % of nitrogen,
The photomask was analyzed by normal mode XRD,
In the normal mode XRD analysis, the maximum peak of the measured X-ray intensity after reflection in the direction of the phase reversal layer is located between 15° and 30° in 2θ,
In the normal mode XRD analysis, the maximum peak of the measured X-ray intensity after reflection in the direction of the transparent substrate is located between 15° and 30° in 2θ,
an apparatus for manufacturing a semiconductor device having a first amorphous index (AI1) of 0.9 to 1.1 expressed by Equation 1 below;
[Equation 1]

In Equation 1 above,
The XM1 is the maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the phase inversion layer,
The XQ1 is the maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the lower surface of the transparent substrate.
transparent substrate; a phase inversion layer disposed on the transparent substrate; and a light blocking layer disposed on at least a portion of the phase shift layer;
The transparent substrate is a synthetic quartz substrate is applied,
The phase reversal layer includes a retardation adjusting layer positioned on the transparent substrate and a protective layer positioned on the retardation adjusting layer,
The phase shift layer includes a transition metal, silicon, oxygen and nitrogen,
The phase difference adjusting layer contains 3 to 10 atomic % of a transition metal, 20 to 50 atomic % of silicon, 2 to 10 atomic % of oxygen, and 40 to 60 atomic % of nitrogen,
The protective layer contains 0.5 to 5 atomic % of a transition metal, 10 to 50 atomic % of silicon, 10 to 50 atomic % of oxygen, and 20 to 40 atomic % of nitrogen,
The photomask was analyzed by normal mode XRD,
In the normal mode XRD analysis, the maximum peak of the measured X-ray intensity after reflection in the direction of the phase reversal layer is located between 15° and 30° in 2θ,
In the normal mode XRD analysis, the maximum peak of the measured X-ray intensity after reflection in the direction of the transparent substrate is located between 15° and 30° in 2θ,
The first amorphous index (AI1) represented by the following Equation 1 is 0.9 to 1.1, the photo mask;
[Equation 1]

In Equation 1 above,
XM1 is the maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the phase inversion layer,
The XQ1 is the maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the lower surface of the transparent substrate.
3. The method of claim 2,
The passivation layer includes a region in which a ratio of nitrogen content to oxygen content in a thickness direction belongs to 0.4 to 2, and wherein the region has a thickness of 30 to 80% when the total thickness of the passivation layer is 100%.
3. The method of claim 2,
When the thickness of the phase reversal layer is 100%, the thickness of the protective layer is 4 to 9%,
The thickness of the protective layer is 25 Å or more and 80 Å or less,
The phase difference adjusting layer has a refractive index of 2 to 4 with respect to ArF light, and an extinction coefficient of 0.3 to 0.7 with respect to ArF light, a photomask.
3. The method of claim 2,
The photomask was analyzed by fixed mode XRD,
In the fixed mode XRD analysis, the first peak, which is the maximum peak of the measured X-ray intensity after reflection in the direction of the phase reversal layer, has 2θ between 15° and 25°,
In the fixed mode XRD analysis, the second peak, which is the maximum peak of the X-ray intensity measured after reflection in the direction of the transparent substrate, has 2θ between 15° and 25°,
a photomask having a second amorphous index (AI2) of 0.9 to 1.1 expressed by Equation 2 below;
[Equation 2]

In Equation 2 above,
wherein XM2 is the intensity value of the first peak,
The XQ2 is the intensity value of the second peak.
3. The method of claim 2,
The third amorphous index (AI3) represented by the following Equation 3 is 0.9 to 1.1, a photo mask;
[Equation 3]

In Equation 3 above,
The AM1 is an area in a region where 2θ is between 15° and 30° in the X-ray intensity graph measured after reflection when normal mode XRD analysis is performed on the phase reversal layer,
The AQ1 is an area in a region where 2θ is between 15° and 30° in the X-ray intensity graph measured after reflection when normal mode XRD analysis is performed on the lower surface of the transparent substrate.
7. The method of claim 6,
The fourth amorphous index (AI4) represented by the following Equation 4 is 0.9 to 1.1, a photo mask;
[Equation 4]

In Equation 4 above,
XM4 is the X-ray intensity reflected when 2θ is 43° in the normal mode XRD analysis performed on the phase reversal layer,
XQ4 is the X-ray intensity reflected when 2θ is 43° in the normal mode XRD analysis performed on the lower surface of the transparent substrate.
transparent substrate; and a phase inversion layer disposed on the transparent substrate;
The transparent substrate is a synthetic quartz substrate is applied,
The phase reversal layer includes a retardation adjusting layer positioned on the transparent substrate and a protective layer positioned on the retardation adjusting layer,
The phase shift layer includes a transition metal, silicon, oxygen and nitrogen,
The blank mask was analyzed by normal mode XRD,
In the normal mode XRD analysis, the maximum peak of the measured X-ray intensity after reflection in the direction of the phase reversal layer is located between 15° and 30° in 2θ,
In the normal mode XRD analysis, the maximum peak of the measured X-ray intensity after reflection in the direction of the transparent substrate is located between 15° and 30° in 2θ,
A blank mask having a first amorphous index (AI1) of 0.9 to 1.1 expressed by the following Equation 1;
[Equation 1]

In Equation 1 above,
The XM1 is the maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the phase inversion layer,
The XQ1 is the maximum value of the measured X-ray intensity when the normal mode XRD analysis is performed on the lower surface of the transparent substrate.
9. The method of claim 8,
The phase reversal layer includes a blank mask having a photon energy of 1.8 to 2.15 eV at a point where the Del_1 value according to Equation A below measured by a spectral elliptic analyzer by applying an incident angle of 64.5°;
[Formula A]

In Equation A, the DPSp value is the phase difference between the P-wave and the S-wave if the phase difference between the P-wave and the S-wave of the reflected light is 180° or less when the phase inversion layer is measured with a spectral elliptic analyzer by applying an incident angle of 64.5° , when the phase difference between the P wave and the S wave of the reflected light exceeds 180°, it is a value obtained by subtracting the phase difference between the P wave and the S wave from 360°,
The PE value is a photon energy within a range of 1.5 to 3.0 eV, when PE ₁ is 1.5 eV and PE ₂ is 3 eV.
10. The method of claim 9,
In the phase reversal layer, when the photon energy measured by a spectral elliptic analyzer with an incident angle of 64.5° is PE ₁ value is 3.0 eV and PE ₂ value is 5.0 eV, Del_2 expressed by Equation B below is 0. a blank mask having a photon energy of 3.9 to 4.7 eV;
[Formula B]

In Equation B, the DPS value is, when the phase shift film surface is measured with a spectral ellipsometer by applying an incident angle of 64.5° on the protective layer, if the phase difference between the P wave and the S wave of the reflected light is 180° or less, the P wave and a phase difference between S-waves, and if the phase difference between the P-wave and S-wave of the reflected light exceeds 180°, it is a value obtained by subtracting the phase difference between the P-wave and S-wave from 360°, and the PE value is a photon within the range of PE ₁ to PE ₂ is energy.
transparent substrate; a phase inversion layer disposed on the transparent substrate; and a light blocking layer disposed on the phase shift layer;
The transparent substrate is a synthetic quartz substrate is applied,
The light blocking layer includes chromium and nitrogen,
When the normal mode XRD analysis is performed through the light-shielding layer, the X-ray intensity peak measured after reflection has a maximum value of 2θ between 15° and 30°,
When the XRD normal mode analysis proceeds through the lower surface of the transparent substrate, the X-ray intensity peak measured after reflection has a maximum value of 2θ between 15° and 30°,
The blank mask may include a blank mask having a fifth amorphous index (AI5) of 0.9 to 0.97 expressed by Equation 5 below;
[Equation 5]

In Equation 5 above,
The XC1 is the maximum value of the X-ray intensity measured through the light-shielding layer,
The XQ1 is the maximum value of the X-ray intensity measured through the lower surface of the transparent substrate.
12. The method of claim 11,
A blank mask having a sixth amorphous index (AI6) of 1.05 to 1.4 expressed by the following Equation 6;
[Equation 6]

In Equation 6 above,
XC4 is the X-ray intensity reflected when 2θ is 43° when the normal mode XRD analysis is performed in the direction of the light blocking layer,
XQ4 is the X-ray intensity reflected when 2θ is 43° when the normal mode XRD analysis is performed in the direction of the lower surface of the transparent substrate.

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