Blank mask, photomask, and method for manufacturing blank mask

Abstract

The present embodiment relates to a blank mask including a light-transmissive substrate and a light-blocking film on the light-transmissive substrate. The light-blocking film includes at least one of a transition metal, oxygen, and nitrogen. The Mtr value of the following first formula is 6 or less: [First Formula] Mtr = |Rsk| x Rku. In the above first formula, the |Rsk| is the absolute value of the Rsk value. The blank mask and the like described above can improve the adhesion between resist films when the resist is applied, and can effectively remove the amount of resist remaining on the surface of the light-blocking film when the resist pattern is removed.

Description

TECHNICAL FIELD

[0001] The present embodiment relates to a blank mask, a photomask, and a method of manufacturing a blank mask. BACKGROUND

[0002] With the high integration of semiconductor devices and the like, there is a demand for the miniaturization of circuit patterns of semiconductor devices. As a result, the importance of photolithography technology, which is a technology for developing a circuit pattern on a wafer surface using a photomask, is more highlighted.

[0003] In order to develop a miniaturized circuit pattern, there is a demand for the shortening of the wavelength of an exposure light source used in an exposure process. Recently, exposure light sources used include an ArF excimer laser (wavelength: 193 nm) and the like.

[0004] On the other hand, photomasks include a binary mask, a phase shift mask, and the like.

[0005] The binary mask has a structure in which a light-blocking layer pattern is formed on a light-transmitting substrate. The binary mask, on the side on which the pattern is formed, transmits exposure light through a transmission portion that does not include a light-blocking layer and blocks the exposure light through a light-blocking portion that includes the light-blocking layer, thereby exposing a pattern on a resist film on the wafer surface. However, in the binary mask, as the pattern is more miniaturized, a problem can occur in the development of the fine pattern due to diffraction of light generated at the edge of the transmission portion in the exposure process.

[0006] The phase shift mask includes a Levenson type mask, an outrigger type mask, and a half-tone type mask. Among them, the half-tone type phase shift mask has a structure in which a pattern formed of a semi-transparent film is formed on a light-transmitting substrate. The half-tone type phase shift mask, on the side on which the pattern is formed, transmits exposure light through a transmission portion that does not include a semi-transparent layer and transmits attenuated exposure light through a semi-transmission portion that includes the semi-transparent layer. The attenuated exposure light has a phase difference compared to the exposure light that passes through the transmission portion. As a result, the diffraction light generated at the edge of the transmission portion is canceled by the exposure light that passes through the semi-transmission portion, and the phase shift mask is capable of forming a finer fine pattern on the wafer surface.

[0007] PRIOR ART DOCUMENT

[0008] PATENT DOCUMENT

[0009] Korean Patent No. 10-1593390

[0010] Korean Patent Laid-Open No. 10-2016-0031423

[0011] Japanese Patent No. 6766676 Summary of the Invention

[0012] Technical issues

[0013] The purpose of this embodiment is to provide a blank mask and a photomask using the blank mask, wherein when a photoresist is coated on the surface of the light-shielding film, the adhesion between the light-shielding film and the photoresist is improved and the coated photoresist is easy to remove.

[0014] Solution to the problem

[0015] A blank mask according to an embodiment of this specification includes: a light-transmitting substrate; and a light-shielding film located on the light-transmitting substrate.

[0016] The aforementioned light-shielding film contains at least one of a transition metal, oxygen, and nitrogen.

[0017] The Mtr value of the surface of the aforementioned light-shielding film, according to the first formula below, is 6 or less.

[0018] [First Form]

[0019] Mtr=|Rsk|×Rku

[0020] In the first equation above, |Rsk| is the absolute value of Rsk.

[0021] The Rsk value can be less than 1.

[0022] The Rku value mentioned above can be 6 or less.

[0023] The Dw value of the aforementioned light-shielding film, according to the second formula below, can be less than 0.01%.

[0024] [Second Form]

[0025]

[0026] In the second equation above,

[0027] The aforementioned Ds refers to the light-shielding film with... The weight of the blank mask was measured by coating the resist film to a certain thickness, drying it, and then removing the resist film.

[0028] Do refers to the weight of the blank mask measured before the resist film is coated on the light-shielding film.

[0029] The aforementioned light-shielding film may include: a first light-shielding layer; and a second light-shielding layer located on the first light-shielding layer.

[0030] The sum of the nitrogen content and oxygen content of the second light-shielding layer can be from 10 atomic% to 35 atomic%.

[0031] The transition metal can include at least one of Cr, Ta, Ti, and Hf.

[0032] The light-shielding film can be a film on which cooling water is directly sprayed for cooling.

[0033] A photomask according to another embodiment of the present specification includes: a light-transmissive substrate; and a light-shielding pattern film on the light-transmissive substrate.

[0034] The light-shielding pattern film contains at least one of a transition metal, oxygen, and nitrogen.

[0035] An Mtr value of a top surface of the light-shielding pattern film according to a first formula below is 6 or less:

[0036] [First Formula]

[0037] Mtr = |Rsk| x Rku

[0038] In the first formula, |Rsk| is an absolute value of the Rsk value.

[0039] A blank mask manufacturing method according to another embodiment of the present specification includes: a preparation step of disposing a light-transmissive substrate and a sputtering target in a sputtering chamber; a film formation step of injecting an atmosphere gas into the sputtering chamber, applying power to the sputtering target, and forming a pre-heat-treated substrate, the pre-heat-treated substrate being a substrate on which a light-shielding film is formed on the light-transmissive substrate; a heat treatment step of heat-treating the pre-heat-treated substrate at 150°C to 330°C for 5 minutes to 30 minutes, thereby forming a pre-cooling-treated substrate; and a cooling step of directly spraying cooling water on a surface of the pre-cooling-treated substrate on the light-transmissive substrate side and a surface of the light-shielding film side to cool, thereby manufacturing a blank mask.

[0040] The blank mask manufacturing method can further include a stabilization step of stabilizing the pre-cooling-treated substrate subjected to the heat treatment step at 30°C to 50°C for 1 minute to 5 minutes.

[0041] In the cooling step, the cooling water can have a temperature of 10°C to 30°C,

[0042] In the cooling step, the cooling water can be sprayed on the surface of the light-shielding film side at an angle of 30° to 75° at a flow rate of 0.5 L / minute to 1.5 L / minute.

[0043] The blank mask includes: the light-transmissive substrate; and the light-shielding film on the light-transmissive substrate.

[0044] The light-shielding film contains at least one of a transition metal, oxygen, and nitrogen.

[0045] The Mtr value according to the following first formula of the surface of the light shielding film is 6 or less.

[0046] [First Formula]

[0047] Mtr = |Rsk| x Rku

[0048] In the above first formula, the |Rsk| is an absolute value of the Rsk value.

[0049] Effects of the Invention

[0050] According to the blank mask and the like of the present application, when a resist film is formed on the surface of the light shielding film, the adhesion between the light shielding film and the resist film is improved, and the resist pattern is easily removed from the surface of the light shielding film pattern. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figures 1 to 4 A schematic view for explaining a blank mask according to an embodiment of the present specification.

[0052] Figure 5 A schematic view for explaining a photomask according to another embodiment of the present specification.

[0053] Figure 6 A schematic view for explaining an Mtr value measurement region of a photomask.

[0054] REFERENCE NUMERALS

[0055] 100: Blank mask

[0056] 10: Light-transmissive substrate

[0057] 20: Light shielding film

[0058] 21: First light shielding layer

[0059] 22: Second light shielding layer

[0060] 25: Light shielding pattern film

[0061] 30: Phase shift film

[0062] 40: Resist film

[0063] 200: Photomask

[0064] A: Region in which Rsk and Rku values can be measured in a light shielding pattern of a photomask DETAILED DESCRIPTION

[0065] Hereinafter, the embodiments will be described in detail so that those of ordinary skill in the art to which the present embodiments belong can easily practice the embodiments. However, the present embodiments can be implemented in various different ways, and are not limited to the embodiments described herein.

[0066] When inherent manufacturing and material tolerances are present in the sense referred to, the terms “about” or “substantially” used in this specification are used to express the meaning of their numerical values ​​or close to their numerical values, and are intended to prevent any unreasonable or illegal use by any third party of the accurate or absolute numerical values ​​disclosed in this embodiment for understanding.

[0067] Throughout this specification, the term "combination of..." used in the Markush-type description refers to a mixture or combination of one or more components selected from the group of components of the Markush-type description, thereby implying the inclusion of one or more components selected from the aforementioned Markush group.

[0068] Throughout this specification, references in the form of "A and / or B" mean "A or B, or A and B".

[0069] Throughout this specification, unless otherwise specified, terms such as “first,” “second,” or “A,” “B,” etc., are used to distinguish them from each other.

[0070] In this specification, "B is located on A" means that B is located on A or may be located on A if there are other layers in between, and should not be interpreted as B being located on the surface of A in contact with it.

[0071] Unless otherwise specified, the use of the singular in this specification is to be interpreted as including the meaning of singular or plural as the context suggests.

[0072] In this instruction manual, room temperature refers to 20°C to 25°C.

[0073] The Rsk value is an evaluation value based on ISO 4287. The Rsk value represents the degree of skewness (symmetry) of the surface profile of the measured object.

[0074] The Rku value is an evaluation value based on ISO 4287. The Rku value represents the sharpness (kurtosis) of the surface profile of an object.

[0075] A peak is the portion of the surface profile of the light-shielding film 20 that is above the baseline (meaning the average height line in the surface profile).

[0076] A valley is the contour portion located below the baseline in the surface contour of the light-shielding film 20.

[0077] Although the present specification describes a case in which the film formed in contact with the light shielding film is a resist film, the features of the embodiments are applicable to all films formed in contact with the light shielding film and removed in a subsequent process. The film formed in contact with the light shielding film is not limited to a resist film.

[0078] With the high integration of semiconductors, finer circuit patterns need to be formed on semiconductor wafers. As the line width of the patterns developed on semiconductor wafers is further reduced, resolution-related problems of the photomask used to develop the above-described patterns also tend to increase.

[0079] The characteristics related to the attachment or removal of the resist film to or from the light shielding film can become a factor that affects the resolution reduction of the photomask. Specifically, depending on the adhesion between the applied resist film and the light shielding film, a phenomenon in which the edge portion of the resist pattern film after development is peeled off from the surface of the light shielding film can occur. In addition, in the process of removing the resist pattern after patterning the light shielding film using the resist pattern as a mask, a problem in which a portion of the resist pattern remains on the surface of the light shielding film pattern can occur. Such a problem can become a cause of particle generation in the semiconductor wafer exposure process.

[0080] The inventors of the present embodiments have confirmed that by controlling the surface roughness characteristics of the light shielding film and the like to improve the adhesion between the light shielding film and the resist film and the easy removability of the resist pattern, the present embodiments have been completed.

[0081] Hereinafter, the present embodiments will be described in detail.

[0082] Figures 1 to 4 To illustrate the blank mask according to the embodiments of the present specification, a schematic view will be described with reference to FIG. 1. Figures 1 to 4 The present embodiments will be described.

[0083] To achieve the above object, a blank mask 100 according to an embodiment disclosed in the present specification includes: a light-transmitting substrate 10; and a light shielding film 20 located on the light-transmitting substrate 10.

[0084] As the material of the light-transmitting substrate 10, as long as it is a material having light-transmitting properties to exposure light and applicable to the photomask 200, it is not limited. Specifically, the light-transmitting substrate 10 can have a transmittance of 85% or more to exposure light having a wavelength of 193 nm. The transmittance can be 87% or more. The transmittance can be 99.99% or less. For example, a synthetic quartz substrate can be used as the light-transmitting substrate 10. In this case, the attenuation of light passing through the light-transmitting substrate 10 can be suppressed.

[0085] In addition, by adjusting the surface characteristics such as the flatness and roughness of the light-transmitting substrate 10, the occurrence of optical distortion can be suppressed.

[0086] The light-blocking film 20 can be located on the front side of the light-transmissive substrate 10.

[0087] The light-blocking film 20 is characterized by being capable of blocking exposure light rays that are incident from the backside of the light-transmissive substrate 10 to a certain extent. Further, when a phase shift film 30 or the like is provided between the light-transmissive substrate 10 and the light-blocking film 20, the light-blocking film 20 can be used as an etching mask in a process of etching the phase shift film 30 or the like in a pattern shape.

[0088] Surface roughness characteristics of a light-blocking film

[0089] The Mtr value of the surface of the light-blocking film 20 according to the following first formula is 6 or less.

[0090] [First formula]

[0091] Mtr = |Rsk| x Rku

[0092] In the above first formula, the |Rsk| is the absolute value of the Rsk value.

[0093] The light-blocking film 20 can be formed by a sputtering process or the like. A sputtering process forms a film by depositing sputtering particles sporadically on the surface of a film formation target. In the case where the light-blocking film 20 is formed by a sputtering process, sputtering particles can be deposited sporadically on the surface of the film formation target. Thus, the surface of the light-blocking film 20 can have a shape in which fine irregularities are distributed.

[0094] For the purpose of patterning the light-blocking film 20, a resist film 40 can be formed on the light-blocking film 20. An etching resist pattern (not shown in the drawings) can be formed on the resist film 40 by an electron beam exposure device or the like. The etching resist pattern can be removed after the patterning of the light-blocking film is completed.

[0095] Factors that affect the adhesion between the light-blocking film 20 and the resist film 40 and the characteristics related to removal include the surface roughness characteristics of the light-blocking film 20 that has been formed, the difference in surface energy between the light-blocking film 20 and the resist film 40, the physical properties of a compound that is treated on the surface of the light-blocking film 20 before the resist film 40 is applied, and the like. In particular, the present embodiment can improve the adhesion between the resist film 40 and the light-blocking film 20, the ease of removal, and the like by controlling the surface roughness characteristics of the light-blocking film 20 and the like. In addition, it is possible to substantially suppress a decrease in the resolution of the photomask 200.

[0096] Specifically, before the resist coating process, in order to improve the adhesion of the light shielding film 20 and the resist film 40, a surface treatment process can be performed on the light shielding film 20, that is, a surface treatment adhesion improving substance such as hexamethyldisilazane (HMDS), other organosilane compounds. In the surface treatment process of the light shielding film 20, according to the roughness distribution in the in-plane direction of the surface of the light shielding film 20, in some areas, particularly in areas where a large number of peaks are concentrated, the adhesion improving substance can not be sufficiently coated. In addition, due to the difference in surface energy between the light shielding film 20 and the resist film 40, and the like, the two films can not have sufficient adhesion.

[0097] In the process of removing the resist pattern after the patterning of the light shielding layer 20 is completed, a part of the resist pattern can not be removed. In particular, a part of the resist pattern can remain in the area where the valley distribution of the patterned light shielding film is concentrated. The residue of the resist pattern can form particles and the like, and sometimes can be one of the causes of reducing the resolution of the photomask 200.

[0098] To solve the above problems, a method of simply reducing the size of the fine concave-convex formed on the surface of the light shielding film 20 by an etchant or the like can be considered. However, due to the trend of gradually miniaturizing the required line width, even the concave-convex with reduced size can cause problems related to the adhesion and removal of the resist film 40. That is, it is necessary to more precisely control the surface properties of the light shielding film.

[0099] In this regard, the inventors of the present embodiment have confirmed that by controlling the Mtr value that can reflect both the skewness and kurtosis properties of the surface of the light shielding film 20, even if there is a fine concave-convex on the surface of the light shielding film 20, the resist film 40 and the light shielding film 20 can exhibit stable adhesion, and when the resist pattern is removed, the formation of resist residues can be effectively suppressed.

[0100] The Rsk value, the Rku value, and the Mtr value of the surface of the light shielding film 20 can be controlled according to the sputtering process conditions when the light shielding film 20 is formed by sputtering; the heat treatment process conditions of the atmosphere gas, the temperature change rate, and the like when the light shielding film 20 is heat treated; the cooling process conditions, and the like. The detailed description of the control method of the Mtr value is repeated with the following content, so it will be omitted.

[0101] The measurement method of the Rsk value, the Rku value, and the Mtr value of the surface of the light shielding film 20 is as follows.

[0102] The Rsk value, the Rku value, and the Mtr value of the surface of the light shielding film 20 are measured in the central area of the surface of the light shielding film 20. The central area of the surface of the light shielding film 20 refers to an area with a width of 1 μm and a length of 1 μm located in the central portion (central part) of the surface of the light shielding film 20.

[0103] The Rsk value and the Rku value of the central region are measured using a two-dimensional roughness meter. At the time of measurement, the scanning speed is set to 0.5 Hz in a non-contact mode. For example, the Rsk value and the Rku value can be measured by applying an XE-150 model of Park Systems Co., Ltd., in which a PPP-NCHR, which is a cantilever model of Park Systems Co., Ltd., is applied as a probe.

[0104] The Mtr value of the surface of the light-blocking film 20 is calculated from the measured Rsk value and Rku value.

[0105] The Mtr value of the surface of the light-blocking film 20 can be 6 or less. The Mtr value can be 4 or less. The Mtr value can be 1.5 or less. The Mtr value can be greater than 0. The Mtr value can be 0.5 or more. In this case, the adhesion of the resist film 40 to the light-blocking film 20 is improved, and the formation of particles caused by resist residues is inhibited.

[0106] The Rsk value of the surface of the light-blocking film 20 can be 1 or less.

[0107] When the Rsk value of the surface of the light-blocking film 20 is controlled within a predetermined range, the formation of a region in which peaks are densely formed, which makes it difficult to stably coat an adhesion-improving substance, is inhibited. Thus, the adhesion between the resist film 40 and the light-blocking film 20 can be induced to be improved. In addition, by appropriately forming valleys on the surface of the light-blocking film, the generation of resist residues can be effectively inhibited.

[0108] The Rsk value of the surface of the light-blocking film 20 can be 1 or less. The Rsk value can be 0.1 or less. The Rsk value can be -1 or more. The Rsk value can be -0.5 or more. In this case, the resist film 40 or the resist pattern can be easily attached to or removed from the light-blocking film 20.

[0109] The Rku value of the surface of the light-blocking film 20 can be 6 or less.

[0110] By controlling the Rku value of the surface of the light-blocking film 20, the adhesion between the light-blocking film 20 and the resist film 40 can be improved. Specifically, by controlling the kurtosis of the peaks formed on the surface of the light-blocking film 20, an adhesion-improving substance can be coated and maintained on the entire surface of the light-blocking film 20 on which fine irregularities are formed, with a sufficient thickness.

[0111] The Rku value of the surface of the light shielding film 20 can be 6 or less. The Rku value can be 4 or less. The Rku value can be 3 or less. The Rku value can be 1 or more. The Rku value can be 2 or more. In this case, the resist pattern on the surface of the light shielding film 20 can be stably maintained according to the designed shape.

[0112] By controlling the Mtr value of the surface of the light shielding film 20, the Rsk value and the Rku value can be adjusted at the same time. If only the Rsk value of the surface of the light shielding film 20 is controlled, the adhesion improving substance cannot be sufficiently coated and maintained on the surface of the light shielding film 20, and thus the above-described resist pattern can not be stably attached to the surface of the light shielding film 20. Further, when only the Rku value of the surface of the light shielding film 20 is controlled within the range set in advance in the present embodiment, the adhesion improving substance coating layer is not stably formed due to the peaks being excessively dense on the surface of the light shielding film 20, or it is difficult to remove the resist pattern due to the valleys being excessively formed. Therefore, by adjusting the Rsk value and the Rku value of the surface of the light shielding film 20 at the same time, the adhesion between the light shielding film 20 and the resist film 40 and the ease of removal of the resist pattern can be improved.

[0113] Ease of removal of resist film of light shielding film

[0114] The Dw value of the light shielding film 20 according to the following second formula can be 0.01% or less:

[0115] [Second Formula]

[0116]

[0117] In the above-described second formula, the Ds is the weight of the blank mask 100 measured after the resist film 40 is coated on the light shielding film 20 to a thickness of 1000 A and dried and then the resist film 40 is removed. The Do is the weight of the blank mask 100 measured before the resist film 40 is coated on the light shielding film 20.

[0118] The Do is the weight of the blank mask 100 measured before the resist film 40 is coated on the light shielding film 20.

[0119] By controlling the Dw value of the light shielding film 20 within the range set in advance, the formation of particles caused by the resist residue can be suppressed.

[0120] The method of measuring the Dw value of the light shielding film 20 is as follows.

[0121] The Do value, which is the weight of the blank mask, is measured before the resist film is formed.

[0122] In measuring the Ds value, the resist solution is applied to the light shielding film 20 by spin coating. Thereafter, the applied resist solution is dried at 140°C for 620 seconds to form a resist film 40. After the applied and dried resist film 40 is dipped in an aqueous hydrogen peroxymonosulfuric acid (H2SO5) solution prepared by mixing sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) and removed, the Ds value is measured.

[0123] The Dw value is calculated from the measured Do value and Ds value.

[0124] As the resist, for example, XFP255 or XFP355 manufactured by Fuji Photo Film Co., Ltd. can be used.

[0125] The Dw value of the light shielding film 20 can be 0.01% or less. The Dw value can be 0.006% or less. The Dw value can be 0.001% or more. The Dw value can be 0.002% or more. In this case, the resolution of the photomask 200 can be inhibited from being reduced by the resist residue.

[0126] Composition and film thickness of light shielding film

[0127] The light shielding film 20 can contain at least one of a transition metal, oxygen, and nitrogen.

[0128] The light shielding layer 20 can include a first light shielding layer 21, and a second light shielding layer 22 on the first light shielding layer 21.

[0129] The present embodiment can contribute to the light shielding film 20 exhibiting desired extinction characteristics by controlling the content of each element contained in the second light shielding layer 22. Further, the side surface of the pattern of the light shielding film 20 can have a shape nearly perpendicular to the surface of the light transmitting substrate when the light shielding film 20 is patterned. Further, the resist pattern can be stably attached and held on the surface of the light shielding film 20 according to the designed shape.

[0130] The second light shielding layer 22 can contain at least one of a transition metal, oxygen, and nitrogen. The second light shielding layer 22 can contain 50 atomic % (at%) to 80 atomic % of the transition metal. The second light shielding layer 22 can contain 55 atomic % to 75 atomic % of the transition metal. The second light shielding layer 22 can contain 60 atomic % to 70 atomic % of the transition metal.

[0131] The sum of the oxygen content and the nitrogen content of the second light shielding layer 22 can be 10 atomic % to 35 atomic %. The sum of the oxygen content and the nitrogen content of the second light shielding layer 22 can be 15 atomic % to 25 atomic %.

[0132] The second light-shielding layer 22 can include nitrogen in a range of 5 atomic % to 20 atomic %. The second light-shielding layer 22 can include nitrogen in a range of 7 atomic % to 13 atomic %.

[0133] In this case, the second light-shielding layer 22 can help the light-shielding film 20 to have excellent extinction characteristics. In addition, during etching of the light-shielding film 20, even if the upper portion of the light-shielding film 20 is exposed to etching gas for a long time, the line width of the patterned light-shielding film can be kept constant in the thickness direction. In addition, when the resist pattern is located on the surface of the second light-shielding layer 22, the resist pattern can be stably attached and maintained without being deformed.

[0134] The first light-shielding layer 21 can include a transition metal, oxygen, and nitrogen. The first light-shielding layer 21 can include the transition metal in a range of 30 atomic % to 60 atomic %. The first light-shielding layer 21 can include the transition metal in a range of 35 atomic % to 55 atomic %. The first light-shielding layer 21 can include the transition metal in a range of 40 atomic % to 50 atomic %.

[0135] The sum of the oxygen content and the nitrogen content of the first light-shielding layer 21 can be in a range of 40 atomic % to 70 atomic %. The sum of the oxygen content and the nitrogen content of the first light-shielding layer 21 can be in a range of 45 atomic % to 65 atomic %. The sum of the oxygen content and the nitrogen content of the first light-shielding layer 21 can be in a range of 50 atomic % to 60 atomic %.

[0136] The first light-shielding layer 21 can include oxygen in a range of 20 atomic % to 40 atomic %. The first light-shielding layer 21 can include oxygen in a range of 23 atomic % to 33 atomic %. The first light-shielding layer 21 can include oxygen in a range of 25 atomic % to 30 atomic %.

[0137] The first light-shielding layer 21 can include nitrogen in a range of 5 atomic % to 20 atomic %. The first light-shielding layer 21 can include nitrogen in a range of 7 atomic % to 17 atomic %. The first light-shielding layer 21 can include nitrogen in a range of 10 atomic % to 15 atomic %.

[0138] In this case, the first light-shielding layer 21 can help the light-shielding film 20 to have excellent extinction characteristics. In addition, when the light-shielding film 20 is patterned, the occurrence of a step that appears on the side surface of the light-shielding pattern film can be suppressed.

[0139] The above-described transition metal can include at least one of Cr, Ta, Ti, and Hf. The above-described transition metal can be Cr.

[0140] The film thickness of the first light-shielding layer 21 can be to The film thickness of the first light-shielding layer 21 can be to The film thickness of the first light-shielding layer 21 can be to In this case, the first light-blocking layer 21 can contribute to making the light-blocking film 20 effectively block the exposure light.

[0141] The film thickness of the second light-blocking layer 22 can be to The film thickness of the second light-blocking layer 22 can be to The film thickness of the second light-blocking layer 22 can be to In this case, the second light-blocking layer 22 can improve the extinction property of the light-blocking film 20 and contribute to making the line width of the light-blocking pattern film have a more uniform value in the thickness direction.

[0142] The film thickness ratio of the second light-blocking layer 22 with respect to the film thickness of the first light-blocking layer 21 can be 0.05 to 0.3. The above film thickness ratio can be 0.07 to 0.25. The above film thickness ratio can be 0.1 to 0.2. In this case, the light-blocking film 20 can have excellent extinction properties. Further, when the above light-blocking film is patterned, the light-blocking pattern film can form a side surface nearly perpendicular to the surface of the light-transmitting substrate.

[0143] Optical properties of the light-blocking film

[0144] The light-blocking film 20 can have an optical density of 1.8 or more for light having a wavelength of 193 nm. The light-blocking film 20 can have an optical density of 1.9 or more for light having a wavelength of 193 nm.

[0145] The light-blocking film 20 can have a transmittance of 1.5% or less for light having a wavelength of 193 nm. The light-blocking film 20 can have a transmittance of 1.4% or less for light having a wavelength of 193 nm. The light-blocking film 20 can have a transmittance of 1.2% or less for light having a wavelength of 193 nm.

[0146] In this case, the pattern including the light-blocking film 20 can effectively block the transmission of the exposure light.

[0147] A phase shift film 30 can be provided between the light-transmitting substrate 10 and the light-blocking film 20. The thin film including the phase shift film 30 and the light-blocking film 20 can have an optical density of 3 or more for light having a wavelength of 193 nm. The above thin film can have an optical density of 3.2 or more for light having a wavelength of 193 nm. In this case, the above thin film can effectively suppress the transmission of the exposure light.

[0148] Other thin films

[0149] As the other thin film, the phase shift film 30, a hard mask film (not shown in the drawing), or the like can be applicable.

[0150] The phase shift film 30 can be located between the light-transmissive substrate 10 and the light-blocking film. The phase shift film 30 substantially suppresses the generation of diffracted light at the edges of the pattern by attenuating the intensity of exposure light that penetrates the phase shift film 30 and adjusting the phase difference of the exposure light.

[0151] The phase shift film 30 can have a phase difference of 170° to 190° for light having a wavelength of 193 nm. The phase difference can be 175° to 185°. The phase shift film 30 can have a transmittance of 3% to 10% for light having a wavelength of 193 nm. The transmittance can be 4% to 8%. In this case, the resolution of the photomask 200 including the phase shift film 30 can be improved.

[0152] The phase shift film 30 can include a transition metal and silicon. The phase shift film 30 can include a transition metal, silicon, oxygen, and nitrogen. The transition metal can be molybdenum.

[0153] A hard mask (not shown) can be provided on the light-blocking film 20. The hard mask can be used as an etching mask film when the light-blocking film 20 pattern is etched. The hard mask can include silicon, nitrogen, and oxygen.

[0154] Photomask

[0155] Figure 5 A schematic view for explaining a photomask according to another embodiment of the present specification. Figure 6 A schematic view for explaining a method of measuring the Mtr value of the surface of the light-blocking pattern film in a photomask. The above-described Figure 5 and Figure 6 will be described.

[0156] A photomask 200 according to another embodiment of the present specification includes a light-transmissive substrate 10, and a light-blocking pattern film 25 located on the light-transmissive substrate 10.

[0157] The light-blocking pattern film 25 includes at least one of a transition metal, oxygen, and nitrogen.

[0158] The Mtr value of the upper surface of the light-blocking pattern film 25 according to the following first equation is 6 or less.

[0159] [First Equation]

[0160] Mtr = |Rsk| x Rku

[0161] In the above-described first equation, the |Rsk| is the absolute value of the Rsk value.

[0162] The method of measuring the Mtr value on the upper surface of the light-blocking pattern layer 25 is the same as the method of measuring the Mtr value of the surface of the light-blocking film 20 in the blank mask 100. However, the Mtr value is measured by setting the measurement area A as an arbitrary area on the upper surface of the light-blocking pattern film 25 in the photomask.

[0163] The light-blocking pattern film 25 can be prepared by patterning the light-blocking film of the blank mask 100 described above.

[0164] The surface roughness characteristics, the easy removal property, the composition, the film thickness, and the optical characteristics of the light-blocking pattern film 25 are described repeatedly with the light-blocking film 20 of the blank mask 100, and thus the description is omitted.

[0165] Method of preparing a light-blocking film

[0166] The method of preparing the blank mask 100 according to an embodiment of the present specification can include a preparation step in which the light-transmissive substrate 10 and the sputtering target are disposed in a sputtering chamber.

[0167] The method of preparing the blank mask 100 according to an embodiment of the present specification can include a film formation step in which an atmosphere gas is injected into the sputtering chamber, and power is applied to the sputtering target to form a pre-heat-treated substrate, which is a substrate on which the light-blocking film 20 is formed on the light-transmissive substrate 10.

[0168] The method of preparing the blank mask 100 according to an embodiment of the present specification can include a heat treatment step in which the pre-heat-treated substrate is heat-treated at 150°C to 330°C for 5 minutes to 30 minutes to form a pre-cooling-treated substrate.

[0169] The method of preparing the blank mask 100 according to an embodiment of the present specification can include a stabilization step in which the pre-cooling-treated substrate is stabilized at 30°C to 50°C for 1 minute to 5 minutes.

[0170] The method of preparing the blank mask according to an embodiment of the present specification can include a cooling step in which cooling water is directly sprayed to cool the surface of the light-transmissive substrate side and the surface of the light-blocking film side of the pre-cooling-treated substrate to prepare the blank mask.

[0171] The method of preparing the blank mask according to an embodiment of the present specification can include a washing step in which the blank mask is washed with a washing liquid.

[0172] The film formation step can include a first light-blocking layer film formation process of forming a first light-blocking layer on the light-transmissive substrate, and a second light-blocking layer film formation process of forming a second light-blocking layer on the first light-blocking layer.

[0173] In the preparation step, a target for forming the light-shielding film can be selected in consideration of the composition of the light-shielding film. As the sputtering target, a target containing a transition metal can be used. The sputtering target can use two or more targets, and one of the targets is a target containing a transition metal. The target containing a transition metal can contain 90 atomic % or more of a transition metal. The target containing a transition metal can contain 95 atomic % or more of a transition metal. The target containing a transition metal can contain 99 atomic % of a transition metal.

[0174] The transition metal can include at least one of Cr, Ta, Ti, and Hf. The transition metal can include Cr.

[0175] The contents regarding the light-transmissive substrate 10 disposed in the sputtering chamber are repeated with the above-described contents, and thus the description will be omitted.

[0176] In the film formation step of the light-shielding film 20, different film formation process conditions can be used when forming each layer included in the light-shielding film 20. In particular, in consideration of the surface roughness characteristics, extinction characteristics, etching characteristics, and the like of the light-shielding film 20, the atmosphere gas composition, the pressure in the chamber, the power applied to the sputtering target, the film formation time, the substrate rotation speed, and the like of each layer can be set to be different.

[0177] The atmosphere gas can include a non-reactive gas, a reactive gas, and a sputtering gas. The non-reactive gas is a gas that does not include an element constituting the light-shielding film. The reactive gas is a gas that includes an element constituting the light-shielding film. The sputtering gas is a gas that is ionized in a plasma atmosphere and collides with the target. The non-reactive gas can include helium. The reactive gas can include a nitrogen-containing gas. For example, the above-described nitrogen-containing gas can be N2, NO, NO2, N2O, N2O3, N2O4, N2O5, or the like. The reactive gas can include an oxygen-containing gas. For example, the above-described oxygen-containing gas can be O2, CO2, or the like. The reactive gas can include a nitrogen-containing gas and an oxygen-containing gas. The above-described reactive gas can include a gas containing both nitrogen and oxygen. For example, the above-described gas containing both nitrogen and oxygen can be NO, NO2, N2O, N2O3, N2O4, N2O5, or the like.

[0178] The sputtering gas can be an Ar gas.

[0179] As the power source that applies power to the sputtering target, a DC power source can be used, or an RF power source can be used.

[0180] In the first light-shielding layer film formation process, the power applied to the sputtering target can be 1.5 kW to 2.5 kW. The above-described power can be 1.6 kW to 2 kW.

[0181] In the first light shielding layer film forming process, the ratio of the flow rate of the reactive gas to the flow rate of the non-reactive gas in the atmosphere gas can be 1.5 to 3. The ratio of the flow rates can be 1.8 to 2.7. The ratio of the flow rates can be 2 to 2.5.

[0182] In the reactive gas, the ratio of the oxygen content to the nitrogen content can be 1.5 to 4. In the reactive gas, the ratio of the oxygen content to the nitrogen content can be 2 to 3. In the reactive gas, the ratio of the oxygen content to the nitrogen content can be 2.2 to 2.7.

[0183] In this case, the first light shielding layer can contribute to the light shielding film having sufficient light extinction properties. Further, the side surface of the light shielding film, which is patterned by controlling the etching properties of the first light shielding layer, can be close to perpendicular to the light transmitting substrate.

[0184] The first light shielding layer film forming process can be performed for 200 seconds to 300 seconds. The first light shielding layer film forming process can be performed for 210 seconds to 240 seconds. In this case, the first light shielding layer can contribute to the light shielding film having sufficient light extinction properties.

[0185] In the second light shielding layer film forming process, the power applied to the sputtering target can be 1 kW to 2 kW. The power can be 1.2 kW to 1.7 kW. In this case, it can be possible to contribute to the improvement of the etching resist pattern adhesion and removability of the light shielding film.

[0186] In the second light shielding layer film forming process, the ratio of the flow rate of the reactive gas to the flow rate of the non-reactive gas in the atmosphere gas can be 0.3 to 0.8. The ratio of the flow rates can be 0.4 to 0.6.

[0187] In the second light shielding layer film forming process, in the reactive gas, the ratio of the oxygen content to the nitrogen content can be 0.3 or less. The ratio can be 0.1 or less. The ratio can be 0.001 or more.

[0188] In this case, it can be possible to stably maintain the shape of the etching resist pattern located on the surface of the second light shielding layer. Further, it can be possible to contribute to the easy removal of the etching resist pattern from the second light shielding layer without a residue. The etching speed of the second light shielding layer is relatively lower than the etching speed of the first light shielding layer, so that the side surface of the patterned light shielding film can have a shape relatively close to perpendicular to the light transmitting substrate.

[0189] The second light shielding layer film forming time can be performed for 10 seconds to 30 seconds. The second light shielding layer film forming time can be performed for 15 seconds to 25 seconds. In this case, it can be possible to contribute to the side surface of the light shielding pattern film having a shape close to a vertical profile.

[0190] In the heat treatment step, the substrate before the heat treatment can be heat-treated to form the substrate before the cooling treatment. Specifically, the heat treatment can be performed after the substrate before the heat treatment is set in the heat treatment chamber.

[0191] In the heat treatment step, the atmosphere temperature can be 150°C to 330°C. The atmosphere temperature can be 170°C to 280°C. The atmosphere temperature can be 200°C to 250°C. In this case, it can be possible to control the surface roughness characteristics of the light-blocking film surface within a predetermined range, and it can be possible to substantially suppress excessive growth of particles in the light-blocking film 20.

[0192] In the heat treatment step, the heat treatment time can be 5 minutes to 30 minutes. The heat treatment time can be 10 minutes to 20 minutes. In this case, the heat treatment step can control the surface roughness characteristics of the light-blocking film within an appropriate range.

[0193] The heat treatment step can be performed once. The heat treatment step can be performed twice or more.

[0194] When the light-blocking film that has been heat-treated is heat-treated again, the atmosphere temperature can be 80°C to 250°C. The atmosphere temperature can be 100°C to 200°C. In this case, it can be possible to effectively suppress excessive growth of particles in the light-blocking film due to the heat treatment performed again, and the light-blocking film can have excellent resist adhesion and removability.

[0195] In the stabilization step, the substrate before the cooling treatment can be stabilized. If the substrate before the cooling treatment is immediately cooled, it can be possible to cause significant damage to the substrate due to a sharp change in temperature. In order to prevent this, the stabilization step can be required.

[0196] The method of stabilizing the substrate before the cooling treatment can be various. For example, the substrate before the cooling treatment can be taken out of the heat treatment chamber and left in an atmosphere at room temperature for a prescribed time. As another example, the substrate before the cooling treatment can be taken out of the heat treatment chamber and stabilized at 30°C to 50°C for 1 minute to 5 minutes. At this time, the substrate before the cooling treatment can be rotated at 20 rpm to 50 rpm for 1 minute to 5 minutes. As another example, a gas that does not react with the blank mask can be injected at a flow rate of 5 L / minute to 10 L / minute to the substrate before the cooling treatment for 1 minute to 5 minutes. At this time, the gas that does not react with the blank mask can have a temperature of 20°C to 40°C.

[0197] In the cooling step, the blank mask can be prepared by cooling the substrate before the cooling treatment. In the cooling step, the substrate before the cooling treatment can be cooled by a water cooling method. Specifically, the cooling can be performed by directly spraying cooling water onto the light-transmissive substrate side surface and the light-shielding film side surface. It has been confirmed through experiments that, when the cooling step is performed by the method of directly spraying cooling water onto the light-shielding film side surface, the Rsk value of the light-shielding film surface is higher and the Rku value is lower than in the case of the air cooling method. This is considered to be because the sharp temperature change applied to the heated light-shielding film surface and the physical friction applied to the light-shielding film surface by the cooling water effectively affect the roughness characteristics of the light-shielding film surface, particularly the peak / valley distribution and the kurtosis of the peak.

[0198] The temperature of the cooling water used in the cooling step can be 10°C to 30°C, in which case the skewness and kurtosis of the fine concave-convex of the light-shielding film surface and the like can be effectively controlled.

[0199] The cooling water can be a fluid that does not cause chemical denaturation of the light-shielding film. The cooling water can be H2O.

[0200] One or more nozzles for spraying cooling water can be provided on the surface of the light-shielding film. One or more nozzles for spraying cooling water can be provided on the surface of the light-shielding film and the surface of the substrate, respectively.

[0201] When two or more nozzles are provided on one surface of the blank mask, the angle formed between the nozzles can be 60 degrees or more when viewed from the one surface. For example, the angle formed between the nozzles can be 90 degrees.

[0202] The nozzles can be provided at a position spaced apart from the surface of the light-shielding film by 5 mm to 20 mm. The nozzles can be provided at a position spaced apart from the surface of the light-shielding film and the surface of the substrate by 5 mm to 20 mm.

[0203] The nozzles can be provided at an angle of 30 degrees to 75 degrees to the surface of the light-shielding film. The nozzles can be provided at an angle of 45 degrees to 60 degrees to the surface of the light-shielding film. The nozzles can be provided at an angle of 30 degrees to 75 degrees to the surface of the substrate. The nozzles can be provided at an angle of 45 degrees to 60 degrees to the surface of the substrate. The nozzles can be provided to face a position spaced apart from the center of the blank mask that is the cooling target. As an example, the nozzles can be provided to face a position spaced apart from the center of the blank mask that is the cooling target by about 10 mm. In this case, the damage to the light-shielding film due to the spraying of cooling water can be minimized, and the surface roughness characteristics of the light-shielding film and the like can be effectively controlled.

[0204] After nozzles are installed on the side surface of the light-shielding film and the side surface of the light-transmitting substrate, cooling water is directly sprayed through the nozzles, thereby controlling the surface roughness characteristics of the light-shielding film.

[0205] The total flow rate of cooling water sprayed onto the surface of the light-shielding film can be from 0.5 L / min to 1.5 L / min. Alternatively, the total flow rate can be from 0.8 L / min to 1.2 L / min. In this case, the kurtosis and skewness of the light-shielding film surface can be substantially controlled without causing any damage to the blank mask.

[0206] The total flow rate of cooling water sprayed onto the surface of the light-transmitting substrate can be from 0.5 L / min to 1.5 L / min. Alternatively, the total flow rate can be from 0.8 L / min to 1.2 L / min. In this case, the temperature distribution of the blank mask in the thickness direction can be controlled relatively uniformly.

[0207] Cooling time can range from 2 to 15 minutes. Cooling time can range from 3 to 10 minutes. In this case, the resist pattern formed on the surface of the light-shielding film can be stably maintained, and it is helpful to remove the resist pattern without residue.

[0208] After the cooling step with cooling water is completed, the cooling water on the surface of the blank mask can be removed by rotating the blank mask. Specifically, after rotating the blank mask at 1000 rpm to 2000 rpm for 30 to 60 seconds, the rotation of the blank mask can be stopped by decelerating at a constant acceleration for 10 to 60 seconds.

[0209] In the cleaning step, a blank mask can be cleaned with a cleaning solution. This cleaning step removes residues from the surface of the light-shielding film. The cleaning step includes: a cleaning solution spraying process, in which the cleaning solution is sprayed onto the blank mask; and a rinsing process, in which the cleaning solution present on the surface of the blank mask is removed using a rinsing solution.

[0210] During the cleaning fluid spraying process, the cleaning fluid can be, for example, an SC-1 (standard clean-1) solution. SC-1 solution is a mixture of ammonia, hydrogen peroxide, and water. SC-1 solution may contain 10 to 20 parts by weight of ammonia, 10 to 20 parts by weight of hydrogen peroxide, and 60 to 80 parts by weight of water. The cleaning fluid spraying process can last from 60 to 600 seconds.

[0211] During the rinsing process, the cleaning fluid present on the surface of the blank mask can be removed by the rinsing fluid. The rinsing fluid can be, for example, ozone water.

[0212] The blank mask prepared by the preparation method described above includes: a light-transmitting substrate and a light-shielding film located on the light-transmitting substrate.

[0213] The light shielding film includes at least one of a transition metal, oxygen, and nitrogen.

[0214] The Mtr value represented by the first formula at the surface of the light shielding film can be 6 or less.

[0215] The light shielding film is a film that is directly sprayed with cooling water on the surface of the light shielding film to cool.

[0216] The contents regarding the above-mentioned blank mask are repeated with the previous contents, and thus the explanation will be omitted.

[0217] Hereinafter, the specific examples will be explained in more detail.

[0218] Preparation Example: Film formation of light shielding film

[0219] In Comparative Example 1, a light-transmissive quartz substrate having a width of 6 inches, a length of 6 inches, and a thickness of 0.25 inches was disposed in a chamber of a DC sputtering apparatus. A chromium target was disposed in the chamber such that the T / S distance was 255 mm and an angle of 25 degrees was formed between the substrate and the target.

[0220] An atmosphere gas in which 19 vol% of Ar, 11 vol% of N2, 36 vol% of CO2, and 34 vol% of He were mixed was introduced into the chamber, and a power of 1.85 kW was applied to the sputtering target to perform a sputtering process for 230 seconds to 330 seconds to form a first light shielding layer.

[0221] After the first light shielding layer was formed, an atmosphere gas in which 57 vol% of Ar and 43 vol% of N2 were mixed was introduced into the chamber, and a power of 1.5 kW was applied to the sputtering target to form a second light shielding layer, thereby preparing a test piece.

[0222] Example 1: After preparing the substrate before heat treatment under the same conditions as Comparative Example 1, the substrate before heat treatment was set in the heat treatment chamber. Thereafter, heat treatment was performed at an atmosphere temperature of 250°C for 15 minutes to prepare a substrate before cooling treatment. The substrate before cooling treatment, which completed the stabilization step, was subjected to cooling treatment by water cooling. Specifically, one nozzle was provided on the light-shielding film side of the substrate before cooling treatment, which completed the stabilization step, and two nozzles were provided on the substrate side. Specifically, one nozzle was provided so that an angle of 60 degrees was formed between the nozzle and the surface of the light-shielding film, and the direction of the nozzle was toward a position of about 10 mm from the center of the substrate before cooling treatment. In addition, two nozzles were provided so that an angle of 60 degrees was formed between the nozzles and the surface of the light-transmitting substrate, an angle of 90 degrees was formed between the nozzles when viewed from the upper surface of the light-transmitting substrate, and the direction of the nozzles was toward a position of about 10 mm from the center of the substrate before cooling treatment.

[0223] Thereafter, cooling water was directly sprayed to the substrate before cooling treatment through the nozzles for 5 minutes to perform cooling treatment, thereby preparing a blank mask sample. The amount of cooling water sprayed from the nozzle located on the light-shielding film was set to 1.1 L / minute, and the amount of cooling water sprayed from each of the nozzles located on the substrate was set to 0.55 L / minute. As the cooling water, H2O at 25°C was used.

[0224] After the blank mask sample, which completed the cooling treatment, was rotated at 1500 rpm for 40 seconds, the rotation of the blank mask sample was stopped by constant deceleration for 15 seconds.

[0225] Example 2: After preparing the substrate before heat treatment under the same conditions as Comparative Example 1, the substrate before heat treatment was set in the heat treatment chamber. Thereafter, heat treatment was performed at an atmosphere temperature of 200°C for 15 minutes to prepare a substrate before cooling treatment. The heat-treated substrate before cooling treatment was stabilized under the same conditions as Example 1. The substrate before cooling treatment, which completed the stabilization step, was subjected to cooling treatment by water cooling. Except that H2O at 20°C was used as cooling water in the cooling treatment conditions, the other conditions were the same as those of Example 1.

[0226] Example 3: After preparing the heat-treated substrate under the same conditions as Comparative Example 1, the heat-treated substrate was set in the heat treatment chamber. Thereafter, heat treatment was performed at an atmosphere temperature of 250°C for 15 minutes to prepare a cooling treatment-preceding substrate. The cooling treatment-preceding substrate subjected to the heat treatment was stabilized under the same conditions as Example 1. The cooling treatment-preceding substrate completed with the stabilization step was subjected to cooling treatment by water cooling, thereby preparing a blank mask sample. Except that H2O at 20°C was used as cooling water in the cooling treatment conditions, the rest was the same as Example 1.

[0227] Example 4: After preparing the heat-treated substrate under the same conditions as Comparative Example 1, the heat-treated substrate was set in the heat treatment chamber. Thereafter, heat treatment was performed at an atmosphere temperature of 250°C for 15 minutes to prepare a cooling treatment-preceding substrate. The cooling treatment-preceding substrate subjected to the heat treatment was stabilized under the same conditions as Example 1. The cooling treatment-preceding substrate completed with the stabilization step was subjected to cooling treatment by water cooling, thereby preparing a blank mask sample. Except that H2O at 20°C was used as cooling water in the cooling treatment conditions, the rest was the same as Example 1.

[0228] Comparative Example 2: After preparing the heat-treated substrate under the same conditions as Comparative Example 1, the heat-treated substrate was set in the heat treatment chamber. Thereafter, heat treatment was performed at an atmosphere temperature of 250°C for 10 minutes to prepare a cooling treatment-preceding substrate. The cooling treatment-preceding substrate subjected to the heat treatment was taken out of the heat treatment chamber, and was subjected to stabilization by rotating the cooling treatment-preceding substrate at 30 rpm for 2 minutes in an atmosphere at 40°C. The cooling treatment-preceding substrate completed with the stabilization step was subjected to cooling treatment by air cooling at an atmosphere temperature of 25°C for 5 minutes, thereby preparing a blank mask sample. The gas used for the cooling treatment was air (Air).

[0229] Comparative Example 3: After preparing the heat-treated substrate under the same conditions as Comparative Example 1, the heat-treated substrate was set in the heat treatment chamber. Thereafter, heat treatment was performed at an atmosphere temperature of 250°C for 15 minutes. After the primary heat treatment, secondary heat treatment was performed at an atmosphere temperature of 350°C for 15 minutes to prepare a cooling treatment-preceding substrate. The cooling treatment-preceding substrate subjected to the secondary heat treatment was stabilized under the same conditions as Example 1. The cooling treatment-preceding substrate completed with the stabilization step was subjected to cooling treatment under the same cooling treatment conditions as Comparative Example 2, thereby preparing a blank mask sample.

[0230] The heat treatment and cooling conditions of each of the examples and comparative examples are described in Table 1 below.

[0231] Evaluation Example: Surface roughness measurement

[0232] The Rsk value and the Rku value of the surface of the light shielding film of Examples 1 to 4 and Comparative Examples 1 to 3 were measured according to ISO_4287, and the Mtr value was calculated from the above-mentioned Rsk value and Rku value.

[0233] Specifically, in a region of 1 um in width and 1 um in length in the center portion of the light shielding film, the Rsk value and the Rku value were measured using a XE-150 model of Korea Park Co., Ltd. in a non-contact mode at a scanning speed of 0.5 Hz, in which PPP-NCHR, which is a cantilever model of Korea Park Co., Ltd., was used as a probe.

[0234] Subsequently, the Mtr value was calculated from the Rsk value and the Rku value measured from each of the examples and each of the comparative examples.

[0235] The measurement results of each of the examples and the comparative examples are described in Table 2 below.

[0236] Evaluation Example: Residual Resist Amount Measurement

[0237] Before forming a resist film on the light shielding film of each of the examples and each of the comparative examples, the Do value, which is the weight of a blank mask, was measured.

[0238] Subsequently, a resist solution was sprayed and coated on the light shielding film of each of the examples and each of the comparative examples by a spin-coating method. Subsequently, the coated resist solution was dried at 140°C for 620 seconds, thereby forming a resist film having a thickness of 1.5 um.

[0239] As the above-mentioned resist solution, a type XFP255 of Japan Fuji Co. was used.

[0240] The Ds value, which is the weight of a blank mask after the above-mentioned resist film was removed, was measured. The resist film was removed by immersion in an aqueous solution of peroxy sulfuric acid, which is a mixed solution of sulfuric acid and hydrogen peroxide.

[0241] The Dw value was calculated from the Ds value and the Do value of each of the examples and each of the comparative examples.

[0242] The measurement results of each of the examples and the comparative examples are described in Table 2 below.

[0243] Table 1

[0244]

[0245] Table 2

[0246] Rsk Rku Mtr Dw Example 1 -0.52 3.833 1.993 0.005 Example 2 -0.756 5.657 4.277 0.008 Example 3 -0.648 3.981 2.58 0.006 Example 4 -0.399 2.494 0.995 0.004 Comparative Example 1 -1.212 9.204 11.155 0.085 Comparative Example 2 -1.017 7.537 7.665 0.017 Comparative Example 3 -2.569 14.006 35.981 0.221

[0247] ​In the above Table 2, the Mtr values of Examples 1 to 4 are 6 or less, while, on the contrary, the Mtr values of Comparative Examples 1 to 3 are 7 or more.

[0248] As for the Dw value, the Dw values of Examples 1 to 4 are 0.01% or less, while, on the contrary, the Dw values of Comparative Examples 1 to 3 are more than 0.01%.

[0249] The above preferred embodiments have been described in detail, but the scope of the present application is not limited thereto, and various modifications and improvements of the present application by those skilled in the art using the basic concept of the present embodiments defined in the scope of the appended claims also belong to the scope of the present application.

Claims

1. A blank mask, characterized in that, include: Transparent substrate, and A light-shielding film is located on the aforementioned light-transmitting substrate; the light-shielding film comprises at least one of a transition metal, oxygen, and nitrogen. The aforementioned light-shielding film includes: First light-shielding layer, and The second light-shielding layer is located on the aforementioned first light-shielding layer; The total nitrogen and oxygen content of the second light-shielding layer is between 10 atomic% and 35 atomic%. The sum of the nitrogen content and the oxygen content of the first light-shielding layer is 40 atomic% to 70 atomic%. The second light-shielding layer comprises 55 atomic% to 75 atomic% of a transition metal, and the first light-shielding layer comprises 35 atomic% to 55 atomic% of a transition metal. The ratio of the thickness of the second light-shielding layer to the thickness of the first light-shielding layer is 0.05 to 0.

3. The Mtr value of the surface of the aforementioned light-shielding film, expressed by the first formula below, is 6 or less. First move: Mtr = |Rsk|×Rku In the first formula above, The above |Rsk| is the absolute value of Rsk.

2. The blank mask according to claim 1, characterized in that, The Rsk value mentioned above is below 1.

3. The blank mask according to claim 1, characterized in that, The Rku value mentioned above is below 6.

4. The blank mask according to claim 1, characterized in that, The Dw value of the aforementioned light-shielding film, expressed by the second formula below, is 0.01% or less. Second move: In the second equation above, The aforementioned Ds refers to the area on the aforementioned light-shielding film at 1300. The weight of the blank mask was measured by coating a resist film to a certain thickness, drying it, and then removing the resist film. Do refers to the weight of the blank mask measured before the resist film is coated on the light-shielding film.

5. The blank mask according to claim 1, characterized in that, The aforementioned transition metals include at least one of Cr, Ta, Ti, and Hf.

6. The blank mask according to claim 1, characterized in that, The aforementioned light-shielding film is a film cooled by directly spraying cooling water onto its surface.

7. A photomask, characterized in that, include: Transparent substrate, and A light-shielding patterned film is located on the aforementioned light-transmitting substrate; The aforementioned light-shielding patterned film contains at least one of a transition metal, oxygen, and nitrogen. The aforementioned light-blocking patterned film includes: First light-shielding layer, and The second light-shielding layer is located on the aforementioned first light-shielding layer; The total nitrogen and oxygen content of the second light-shielding layer is between 10 atomic% and 35 atomic%. The sum of the nitrogen content and the oxygen content of the first light-shielding layer is 40 atomic% to 70 atomic%. The second light-shielding layer comprises 55 atomic% to 75 atomic% of a transition metal, and the first light-shielding layer comprises 35 atomic% to 55 atomic% of a transition metal. The ratio of the thickness of the second light-shielding layer to the thickness of the first light-shielding layer is 0.05 to 0.

3. The Mtr value of the upper surface of the aforementioned light-shielding patterned film, as expressed by the first formula below, is 6 or less. First move: Mtr = |Rsk|×Rku In the first formula above, The above |Rsk| is the absolute value of Rsk.

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