Blank mask, photomask using the same, and method of manufacturing semiconductor device

Abstract

The present invention relates to a blank mask, a photomask using the same, and a method for manufacturing a semiconductor element. The blank mask includes a light-transmissive substrate and a light-shielding film disposed on the light-transmissive substrate. The light-shielding film contains at least any one of a transition metal, oxygen, and nitrogen. The light-shielding film includes a first light-shielding layer and a second light-shielding layer disposed on the first light-shielding layer. The Rd value of the light-shielding film in the following formula 1 is 0.4 to 0.8. [Formula 1] Rd = er2 / er1. In the above formula 1, the er1 value is the etching rate of the first light-shielding layer measured by etching with argon gas. The er2 value is the etching rate of the second light-shielding layer measured by etching with argon gas. According to the blank mask of the present invention, a decrease in pattern resolution can be effectively suppressed when patterning the light-shielding film.

Description

Technical Field

[0001] This embodiment relates to a blank mask, a photomask using the blank mask, and a method for manufacturing a semiconductor device. Background Art

[0002] As semiconductor devices and the like become increasingly integrated, their circuit patterns need to be refined. Consequently, the importance of photolithography, a technique for developing circuit patterns on wafer surfaces using photomasks, has been further emphasized.

[0003] In order to develop finer circuit patterns, the exposure light source used in the exposure process is required to have a shorter wavelength. Recently used exposure light sources include ArF excimer lasers (wavelength of 193 nm).

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

[0005] A binary mask has a structure with a light-shielding layer pattern formed on a transparent substrate. On the patterned surface of the binary mask, transmissive portions without the light-shielding layer allow exposure light to pass through, while light-shielding portions with the light-shielding layer block the exposure light, thereby exposing the pattern on the resist film on the wafer surface. However, as the pattern becomes finer in a binary mask, light diffraction generated at the edges of the transmissive portions during the exposure process can cause problems in developing the fine pattern.

[0006] Phase-shift masks include Levenson-type masks, Outrigger-type masks, and half-tone-type masks. A half-tone-type phase-shift mask has a structure in which a pattern formed by a semi-transparent film is arranged on a light-transmitting substrate 10. On the surface of the half-tone-type phase-shift mask provided with the pattern, the transmissive portion that does not include a semi-transmissive layer allows the exposure light to pass through, while the semi-transmissive portion that includes a semi-transmissive layer allows the attenuated exposure light to pass through. The attenuated exposure light has a phase difference compared to the exposure light that passes through the transmissive portion. Thus, the diffracted light generated at the edge of the transmissive portion is offset by the exposure light that passes through the semi-transmissive portion, thereby enabling the phase-shift mask to form a finer pattern on the surface of the wafer.

[0007] Prior art literature

[0008] Patent Literature

[0009] Korean Patent No. 10-1579843

[0010] Korean Patent No. 10-1584383

[0011] Korean Patent No. 10-1207724 SUMMARY OF THE INVENTION

[0012] TECHNICAL PROBLEM TO BE SOLVED

[0013] An object of the present embodiment is to provide a blank mask capable of effectively suppressing a decrease in pattern resolution when patterning a light-shielding film, a photomask using the same, and a method for manufacturing a semiconductor device.

[0014] MEANS FOR SOLVING THE PROBLEM

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

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

[0017] The light-shielding film includes a first light-shielding layer and a second light-shielding layer disposed on the first light-shielding layer.

[0018] The Rd value of the light-shielding film in Formula 1 below is 0.4 to 0.8.

[0019] [Formula 1]

[0020]

[0021] In Formula 1 above, the er1 value is the etching rate of the first light-shielding layer measured by etching with argon.

[0022] The er2 value is the etching rate of the second light-shielding layer measured by etching with argon.

[0023] The er2 value may be to

[0024] The er1 value may or more.

[0025] The Do value of the light-shielding film in Formula 2 below may be less than 0.05.

[0026] [Formula 2]

[0027] Do = Bo - Po

[0028] In Formula 2 above, the Bo value is the optical density of the light-shielding film measured under exposure light having a wavelength of 193 nm.

[0029] The above Po value is the optical density of the light-shielding pattern film measured by irradiating the measurement area of the light-shielding pattern film with exposure light having a wavelength of 193 nm. The light-shielding pattern film is formed by patterning the above light-shielding film. When observing the light-shielding pattern film from above, the measurement area is an area from one edge formed by patterning of the above light-shielding pattern film to a position 4 nm apart in the inner direction of the above light-shielding pattern film.

[0030] The above transition metal may include at least any one of Cr, Ta, Ti, and Hf.

[0031] The etching rate of the above light-shielding film with respect to the chlorine-based gas may be above.

[0032] A blank mask according to another embodiment of the present specification includes a light-transmissive substrate and a light-shielding film disposed on the above light-transmissive substrate.

[0033] The above light-shielding film includes at least any one of a transition metal, oxygen, and nitrogen.

[0034] The above light-shielding film includes a first light-shielding layer and a second light-shielding layer disposed on the above first light-shielding layer.

[0035] The pattern edge loss area measured by patterning the above light-shielding film is 10 nm 2 below.

[0036] The above pattern edge loss area is the area surrounded by a first line, a second line, and the pattern edge contour of the light-shielding pattern film when measuring a transmission electron microscopy (TEM) image of the light-shielding pattern film formed by patterning the above light-shielding film and observing the above transmission electron microscopy image.

[0037] The above first line is an extension line formed by connecting a first point located at 20% of the total height and a second point located at 40% of the total height in the side profile of the above light-shielding pattern film when the total height of the above light-shielding pattern film is set to 100%.

[0038] The above second line is an extension line including a pattern film intersection point and disposed parallel to the upper surface of the above light-transmissive substrate.

[0039] The above pattern film intersection point is a point where the center line of the pattern film meets the upper surface contour of the above light-shielding pattern film.

[0040] The above pattern film center line is an extension line passing through the center point of the bottom surface of the above light-shielding pattern film, that is, the pattern film center point, and perpendicular to the upper surface of the above light-transmissive substrate.

[0041] A photomask according to another embodiment of the present specification includes a light-transmissive substrate and a light-shielding pattern film disposed on the light-transmissive substrate.

[0042] The light-shielding pattern film contains at least any one of a transition metal, oxygen, and nitrogen.

[0043] The light-shielding pattern film includes a first light-shielding layer and a second light-shielding layer disposed on the first light-shielding layer.

[0044] The Rd value of the light-shielding film in Formula 1 below is 0.4 to 0.8.

[0045] [Formula 1]

[0046]

[0047] In Formula 1 above, the er1 value is the etching rate of the first light-shielding layer measured by etching with argon gas.

[0048] The er2 value is the etching rate of the second light-shielding layer measured by etching with argon gas.

[0049] When observing the cross-section of the light-shielding pattern film, the pattern edge loss area of the light-shielding pattern film measured on the cross-section can be 10 nm 2 or less.

[0050] A method for manufacturing a semiconductor device according to another embodiment of the present specification includes: a preparation step of arranging a light source, a photomask, and a semiconductor wafer coated with a resist film; an exposure step of selectively transmitting light incident from the light source through the photomask onto the semiconductor wafer and emitting the light; and a development step of developing a pattern on the semiconductor wafer.

[0051] The photomask includes: a light-transmissive substrate; and a light-shielding pattern film disposed on the light-transmissive substrate.

[0052] The light-shielding pattern film contains at least any one of a transition metal, oxygen, and nitrogen.

[0053] The light-shielding pattern film includes a first light-shielding layer and a second light-shielding layer disposed on the first light-shielding layer.

[0054] The Rd value of the light-shielding pattern film in Formula 1 below is 0.4 to 0.8.

[0055] [Formula 1]

[0056]

[0057] In Formula 1 above, the er1 value is the etching rate of the first light-shielding layer 21 measured by etching with argon gas.

[0058] The above-mentioned er2 value is the etching rate of the above-mentioned second light-shielding layer etched and measured using argon gas.

[0059] Advantages of the Invention

[0060] According to the blank mask and the like of the present embodiment, it is possible to effectively suppress the reduction in the resolution of the pattern that may occur when patterning the light-shielding film. Description of the Drawings

[0061] Figure 1 It is a schematic diagram for explaining a blank mask according to an embodiment disclosed in the present specification.

[0062] Figure 2 It is a schematic diagram for explaining a light-shielding pattern film formed by patterning the light-shielding film of a blank mask to be measured according to another embodiment.

[0063] Figure 3 It is a plan view of a light-shielding pattern film formed by patterning the light-shielding film according to still another embodiment as viewed from above.

[0064] Figure 4 It is a schematic diagram for explaining a method of measuring the pattern edge loss area of a light-shielding pattern film formed by patterning the light-shielding film according to still another embodiment.

[0065] Figure 5 It is a schematic diagram for explaining a blank mask according to still another embodiment.

[0066] Figure 6 It is a schematic diagram for explaining a photomask according to still another embodiment.

[0067] Description of Reference Numerals

[0068] 100: Blank mask

[0069] 10: Transparent substrate

[0070] 20: Light-shielding film

[0071] 21: First light-shielding layer

[0072] 22: Second light-shielding layer

[0073] 30: Phase shift film

[0074] 150: Mask formed by patterning the light-shielding film of a blank mask to be measured

[0075] 23: Light-shielding pattern film obtained by patterning the light-shielding film of a blank mask to be measured

[0076] 200: Photomask

[0077] 25: Light-shielding pattern film

[0078] Le: An edge formed by patterning in the light-shielding pattern film

[0079] L1: First line L2: Second line L0: Center line of the pattern film

[0080] p1: First point p2: Second point p c : Center point p of the pattern film i : Intersection point of the pattern film

[0081] Ap: Pattern edge loss area

[0082] Am: Measurement area Detailed implementation manners

[0083] In the following, embodiments will be described in detail so that those of ordinary skill in the art to which this implementation manner pertains can easily implement the embodiments. This implementation manner can be realized in many different ways and is not limited to the embodiments described herein.

[0084] In this specification, terms such as "about" or "substantially" used for degrees mean having a meaning close to the specified value or range with an allowable error, and are intended to prevent the accurate or absolute value disclosed in this implementation manner from being used improperly or illegally by any unreasonable third party.

[0085] Throughout this specification, the term "these combinations" included in the Markush-form expressions means one or more mixtures or combinations selected from the group consisting of multiple structural elements described in the Markush-form expressions, and means including one or more selected from the group consisting of the above multiple structural elements.

[0086] Throughout this specification, the description in the form of "A and / or B" means "A, B, or A and B".

[0087] Throughout this specification, unless otherwise specified, terms such as "first", "second", or "A", "B", etc. are used to distinguish the same terms from each other.

[0088] In this specification, the meaning that B is located on A means that B is located on A or, when there are other layers in between, B is located on A or may be located on A, and should not be interpreted as meaning that B is located on the surface of A in a contacting manner.

[0089] Unless otherwise specified, in this specification, singular expressions are interpreted to include the singular or plural meanings as interpreted in the context.

[0090] In this specification, room temperature means 20°C to 25°C.

[0091] In this specification, the surface profile of the light-shielding pattern film refers to the profile of the light-shielding pattern film observed from the cross-section of the light-shielding pattern film when observing the cross-section of the light-shielding pattern film using a transmission electron microscopy (TEM) measurement device or the like.

[0092] In this specification, the side profile of the light-shielding pattern film refers to the profile of the side of the light-shielding pattern film observed from the cross-section of the light-shielding pattern film when observing the cross-section of the light-shielding pattern film using a transmission electron microscopy measurement device or the like.

[0093] In this specification, the pattern edge profile of the light-shielding pattern film refers to the profile of the upper edge and its peripheral part of the light-shielding pattern film observed from the cross-section of the light-shielding pattern film when observing the cross-section of the light-shielding pattern film using a transmission electron microscopy measurement device or the like.

[0094] With the high integration of semiconductors, it is necessary to form finer circuit patterns on semiconductor wafers. As the line width of the patterns developed on semiconductor wafers further decreases, related problems regarding the resolution of photomasks tend to increase.

[0095] The light-shielding film included in a blank mask can be formed into a light-shielding pattern film by etching or the like. Using a resist pattern or other thin film pattern disposed on the light-shielding film as a mask and an etching gas as an etchant, the light-shielding pattern film is formed by etching.

[0096] When patterning the light-shielding film by a dry etching method using an etching gas as an etchant, the light-shielding pattern film formed by patterning may exhibit non-uniform optical characteristics in the in-plane direction. Specifically, the etching gas can etch the light-shielding film from the surface of the light-shielding film to the lower part of the light-shielding film along the resist pattern or the etching mask. During the etching process, in the side surface of the formed light-shielding pattern film, the upper region of the side surface may be exposed to the etching gas for a relatively longer time compared to the lower region of the side surface. Therefore, unnecessary etching may occur in the in-plane direction of the light-shielding film in the upper region of the side surface of the light-shielding pattern film. This may be one of the factors reducing the resolution of the blank mask.

[0097] The inventors of the present embodiment confirmed that by introducing a multilayer structure into the light-shielding film and making the upper layer structure denser than the lower layer structure or the like, it is possible to effectively suppress the reduction in the resolution of the blank mask, thereby completing the present embodiment.

[0098] Hereinafter, the present embodiment will be described in detail.

[0099] Figure 1Schematic diagram for explaining a blank mask according to an embodiment disclosed in this specification. Hereinafter, reference will be made to the above-mentioned Figure 1 to explain the blank mask of this embodiment.

[0100] The blank mask 100 includes a light-transmitting substrate 10 and a light-shielding film 20 disposed on the light-transmitting substrate 10.

[0101] As the material of the light-transmitting substrate 10, as long as it has light-transmitting properties for the exposure light and can be applied to the blank mask 100, there is no limitation. Specifically, the transmittance of the light-transmitting substrate 10 for the exposure light with a wavelength of 193 nm can be 85% or more. The above transmittance can be 87% or more. The above transmittance can be 99.99% or less. For example, a synthetic quartz substrate can be applied as the light-transmitting substrate 10. In this case, the light-transmitting substrate 10 can suppress the attenuation of the light transmitted through the light-transmitting substrate 10.

[0102] 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.

[0103] The light-shielding film 20 can be located on the top side of the light-transmitting substrate 10.

[0104] The light-shielding film 20 can have the characteristic of being able to block at least a certain part of the exposure light incident from the bottom side of the light-transmitting substrate 10. And, a phase shift film 30 (refer to Figure 5 ) etc. can be located between the light-transmitting substrate 10 and the light-shielding film 20. In this case, the light-shielding film 20 can be used as an etching mask in the process of etching the phase shift film 30 etc. into a pattern shape. 1]

[0105] The light-shielding film 20 contains at least any one of a transition metal, oxygen, and nitrogen.

[0106] The light-shielding film 20 includes a first light-shielding layer 21 and a second light-shielding layer 22 disposed on the first light-shielding layer 21.

[0107] Density of each layer of the light-shielding film

[0108] The Rd value of the following formula 1 of the light-shielding film 20 is 0.4 to 0.8.

[0109] [Formula 1]

[0110]

[0111] In the above formula 1, the above er1 value is the etching rate of the first light-shielding layer 21 measured by etching with argon gas. [[ID=J1]]

[0112] The above-mentioned er2 value is the etching rate of the second light-shielding layer 22 measured by etching with argon gas.

[0113] In the process of patterning the light-shielding film 20, the upper side of the side surface of the light-shielding pattern film may be exposed to the etching gas for a relatively longer time than the lower side. Therefore, in the upper region of the side surface of the light-shielding pattern film, unnecessary etching may occur in the in-plane direction of the light-shielding film 20. Therefore, it is difficult for the side surface of the light-shielding pattern film to form an angle close to perpendicular to the surface of the light-transmissive substrate 10.

[0114] To solve the above problems, a control method can be considered as follows, that is, the content of the transition metal in the second light-shielding layer 22 is adjusted to be relatively larger than the content of the transition metal in the first light-shielding layer 21, thereby making the etching rate of the second light-shielding layer 22 based on the etchant lower than the etching rate of the first light-shielding layer 21 based on the etchant. However, even if the above method is applied to reduce the degree of damage formed at the edge portion of the second light-shielding layer 22, due to the trend of the line width of the required pattern to be gradually refined, the damage formed at the above edge portion may still cause problems related to the resolution of the photomask. In addition, when only considering the precise control of the side profile of the light-shielding pattern film and adjusting the content of the transition metal contained in the second light-shielding layer 22, problems such as a low etching rate of the light-shielding film and defects caused by Cr migration may occur. That is to say, in addition to adjusting the composition content of each layer of the light-shielding film, it is also necessary to more precisely control the side profile of the light-shielding pattern film formed by the patterning process by adjusting other characteristics of each layer including the degree of densification, etc.

[0115] On the other hand, the etching gas used in the patterning of the light-shielding film 20 will be accompanied by a chemical reaction with the light-shielding film 20. Therefore, the etching rate of each layer in the light-shielding film 20 measured by the etching gas may be greatly affected by the elements constituting each layer and the reactivity with the etching gas, etc. The inventors of the present embodiment judged that the values measured by the etching gas are difficult to directly reflect the degree of densification of each layer.

[0116] On the other hand, argon-based etching corresponds to physical etching that is substantially not accompanied by a chemical reaction with the light-shielding film 20 to be etched. Therefore, under the condition that all other conditions are the same, the etching rate measured by etching with argon gas is considered to be a parameter that is independent of the composition and chemical reactivity of each layer in the light-shielding film 20 and can effectively reflect the degree of densification of each layer in the light-shielding film 20.

[0117] Therefore, the inventors of the present embodiment have confirmed that by controlling the Rd value that can reflect the degree of dense formation of the first light-shielding layer 21 and the second light-shielding layer 22, it is possible to more precisely control the side profile of the light-shielding pattern film formed when patterning the light-shielding film 20.

[0118] The er1 value, er2 value, and Rd value can be controlled according to various factors. Specifically, the above values may be affected by various factors such as the density of the light-shielding layer, the degree of crystallization of the elements contained in the light-shielding layer, the content of non-metallic elements in the light-shielding layer, and the arrangement of each constituent element in the light-shielding layer. In particular, according to process conditions including the magnet rotation speed during film formation of each layer in the light-shielding film 20, post-treatment process conditions such as cooling treatment after film formation, etc., the above values will change. The detailed description of the control means of the Rd value is repeated in the following content, so it will be omitted.

[0119] The method for measuring the Rd value of the light-shielding film 20 is as follows.

[0120] First, use a Transmission Electron Microscopy (TEM) to measure the thicknesses of the first light-shielding layer 21 and the second light-shielding layer 22, respectively. Prepare a sample by processing a blank mask 100 to be measured into a size of 15 mm in width and 15 mm in length. After performing Focused Ion Beam (FIB) processing on the surface of the above sample, place it in a TEM image measurement device and measure the TEM image of the above sample. Calculate the thicknesses of the first light-shielding layer 21 and the second light-shielding layer 22 from the above TEM image, respectively.

[0121] Exemplarily, the TEM image can be measured by the JEM-2100F HR model of Japan Electron Optics Laboratory (JEOL).

[0122] After that, etch the above sample with argon to measure the etching times of the first light-shielding layer 21 and the second light-shielding layer 22, respectively. Place the above sample in an X-ray Photoelectron Spectroscopy (XPS) measurement device and etch a region with a width of 4 mm and a length of 2 mm at the center of the above sample with argon to measure the etching time of each layer. When measuring the etching time of each layer, the vacuum degree in the measurement device is 1.0×10 -8 mbar, the X-ray source is Monochromator Al Kα (1486.6 eV), the anode power is 72 W, the anode voltage is 12 kV, and the voltage of the argon ion beam is 1 kV.

[0123] Exemplarily, the XPS measurement device can be the K-Alpha model of Thermo Fisher Scientific Inc.

[0124] The er1 value, er2 value, and Rd value are calculated from the measured thicknesses and etching rates of the first light-shielding layer 21 and the second light-shielding layer 22.

[0125] The Rd value of the light-shielding film 20 can be from 0.4 to 0.8. The Rd value of the light-shielding film 20 can be from 0.5 to 0.77. The Rd value of the light-shielding film 20 can be from 0.6 to 0.8. The Rd value of the light-shielding film 20 can be from 0.6 to 0.7. In this case, the side profile of the light-shielding pattern film formed by patterning the light-shielding film can be controlled more precisely.

[0126] The er2 value of the light-shielding film 20 can be from 0.4 / s to 0.5 / s. The er2 value of the light-shielding film 20 can be from 0.4 / s to 0.47 / s. The er2 value of the light-shielding film 20 can be from 0.42 / s to 0.45 / s. In this case, it is possible to more easily control the Rd value of the light-shielding film within the preset range in this embodiment, and it is possible to effectively suppress the formation of particles caused by the re-deposition of sputtered particles (Redeposition) described below.

[0127] The er1 value of the light-shielding film 20 can be above. The er1 value of the light-shielding film 20 can be above. The er1 value of the light-shielding film 20 can be above. The er1 value of the light-shielding film 20 can be below. The er1 value of the light-shielding film 20 can be below. The er1 value of the light-shielding film 20 can be below. In this case, it is possible to more easily adjust the Rd value of the light-shielding film and to more effectively etch the light-shielding film.

[0128] Optical properties of the light-shielding film

[0129] The Do value of the following formula 2 of the light-shielding film 20 can be less than 0.05.

[0130] [Formula 2]

[0131] Do = Bo - Po

[0132] In the above formula 2, the above Bo value is the optical density of the light-shielding film 20 measured by irradiating exposure light with a wavelength of 193 nm.

[0133] The above Po value is the optical density of the light-shielding pattern film measured when exposing the measurement area of the light-shielding pattern film formed by patterning the above light-shielding film 20 with exposure light having a wavelength of 193 nm while observing from above, and the measurement area corresponds to the area from one edge Le (refer to Figure 3 ) formed by patterning of the light-shielding pattern film to a position 4 nm apart in the inner direction of the light-shielding pattern film.

[0134] Figure 2 FIG. is a schematic diagram for explaining a light-shielding pattern film formed by patterning a light-shielding film of a blank mask to be measured. Hereinafter, reference will be made to Figure 2 to explain this embodiment.

[0135] The light-shielding pattern film 23 is formed by patterning the light-shielding film 20. The side surface of the light-shielding pattern film 23 (the yz plane of the light-shielding pattern film 23), as long as it is not the side surface of the blank mask itself, is usually formed by etching. The upper region of the side surface formed by the above etching (the region above the yz plane of the light-shielding pattern film 23 in the z-axis direction) is exposed to the etchant for a longer time, so more etching may occur compared with the lower region of the above side surface (the region below the yz plane of the light-shielding pattern film 23 in the z-axis direction). Therefore, the portions adjacent to the two ends of the light-shielding pattern film 23 (the edges on both sides of the light-shielding pattern film 23 in the x-axis direction) may have a relatively thinner thickness compared with the central portion of the light-shielding pattern film 23 (the portion at the center of the light-shielding pattern film 23 in the x-axis direction). Therefore, light extinction characteristic deviation in the in-plane direction of the light-shielding pattern film 23 may occur. This embodiment can provide a blank mask that effectively suppresses resolution degradation caused by patterning by controlling the Do value of the light-shielding film.

[0136] In order to control the Do value of the light-shielding film 20, not only other conditions of each layer in the light-shielding film 20 need to be controlled, but also there are differences in the density of each layer contained in the light-shielding film itself. And the above density may be affected not only by the composition, but also by process conditions during sputtering and post-treatment process conditions including a cooling step after sputtering. Since the description of the above control means is repeated with the following content, its description will be omitted.

[0137] Figure 3 FIG. is a plan view of a light-shielding pattern film formed by patterning a light-shielding film as observed from above. Hereinafter, reference will be made to Figure 3 to explain this embodiment.

[0138] The Bo value is measured by irradiating the surface of the light-shielding film 20 before patterning with exposure light having a wavelength of 193 nm. When another thin film (e.g., a hard mask) is formed on the light-shielding film, the Bo value is measured after removing the above-mentioned another thin film by etching. When etching the another thin film formed on the light-shielding film, the difference between the thickness of the light-shielding film 20 before etching and the thickness of the light-shielding film 20 after etching is set within 3 nm.

[0139] Thereafter, the Po value is measured from the light-shielding pattern film 23 formed by patterning the light-shielding film 20. When observing the above-mentioned light-shielding pattern film 23 from above, the region corresponding to the region from one edge Le formed by patterning of the above-mentioned light-shielding pattern film 23 to a position 4 nm away in the inner direction of the above-mentioned light-shielding pattern film 23 is defined as the measurement region Am. The Po value is measured by irradiating the above-mentioned measurement region Am with exposure light having a wavelength of 193 nm.

[0140] The Do value is calculated from the measured above-mentioned Bo value and Po value.

[0141] The above-mentioned Bo value and Po value can be measured by an ellipsometer. For example, the MG Pro model of NANO-VIEW Co., Ltd. in Korea can be used to measure the above-mentioned Bo value and Po value.

[0142] The Do value of the light-shielding film 20 can be less than 0.05. The Do value of the light-shielding film 20 can be 0.04 or less. The Do value of the light-shielding film 20 can be 0.03 or less. The Do value of the light-shielding film 20 can be 0.02 or less. The Do value of the light-shielding film 20 can be 0.01 or more. In this case, it is possible to effectively suppress the resolution degradation of the blank mask 100 caused by the patterning of the light-shielding film 20.

[0143] The Bo value of the light-shielding film 20 can be 1.8 or more. The Bo value of the light-shielding film 20 can be 1.85 or more. The Bo value of the light-shielding film 20 can be 3 or less. In this case, the thin film laminate including the light-shielding film 20 can effectively block the transmission of exposure light.

[0144] The Po value of the light-shielding film 20 can be 1.8 or more. The Po value of the light-shielding film 20 can be 1.82 or more. The Po value of the light-shielding film 20 can be 3 or less. The Po value of the light-shielding film 20 can be 2 or less. The Po value of the light-shielding film 20 can be 1.9 or less. In this case, it is possible to effectively help suppress the resolution degradation of the blank mask 100.

[0145] For light with a wavelength of 193 nm, the light-shielding film 20 may have a transmittance of more than 1%. For light with a wavelength of 193 nm, the light-shielding film 20 may have a transmittance of more than 1.3%. For light with a wavelength of 193 nm, the light-shielding film 20 may have a transmittance of more than 1.4%. For light with a wavelength of 193 nm, the light-shielding film 20 may have a transmittance of 2% or less. In this case, the thin film including the light-shielding film 20 can effectively suppress the transmission of exposure light.

[0146] Etching characteristics of the light-shielding film

[0147] The etching rate of the above light-shielding film 20 for chlorine-based gases can be or more.

[0148] In order to improve the resolution of the blank mask 100, it may be necessary to thin the resist film or etching mask film disposed on the light-shielding film 20. When patterning the light-shielding film 20, the etching rate of the light-shielding film 20 for the etchant is controlled, so that even if a relatively thin resist film or the like is formed on the light-shielding film 20, the light-shielding film 20 can be patterned.

[0149] The etchant for the light-shielding film 20 may include chlorine-based gases. The chlorine-based gases may include chlorine gas (Cl2) and oxygen gas (O2).

[0150] The etching characteristics of the light-shielding film 20 for chlorine-based gases can be controlled by the density of each layer of the light-shielding film 20, the content distribution of each element in the thickness direction of the light-shielding film 20, the process conditions when forming the light-shielding film 20, the cooling rate after film formation, etc.

[0151] The method for measuring the etching rate of the light-shielding film 20 for chlorine-based gases is as follows.

[0152] [[ID=...]]

[0153] Exemplarily, the TEM image can be measured by the JEM-2100F HR model of Japan Electron Optics Laboratory (JEOL).

[0154] ​Thereafter, the etching time of the light-shielding film 20 with respect to the chlorine-based gas is measured. As the chlorine-based gas, a gas containing 90 vol% to 95 vol% of chlorine gas and 5 vol% to 10 vol% of oxygen gas is applied. The etching rate of the light-shielding film 20 with respect to the chlorine-based gas is calculated from the thickness of the light-shielding film 20 and the etching time of the light-shielding film 20.

[0155] The etching rate of the light-shielding film 20 with respect to the chlorine-based gas can be or more. The above etching rate can be or more. The above etching rate can be or more. The above etching rate can be or less. In this case, by thinning the resist film disposed on the light-shielding film 20, it is possible to effectively suppress a decrease in the resolution of the blank mask 100.

[0156] Pattern edge loss area of the light-shielding film

[0157] A blank mask according to another embodiment of the present specification includes a light-transmissive substrate and a light-shielding film disposed on the light-transmissive substrate.

[0158] The light-shielding film contains at least any one of a transition metal, oxygen, and nitrogen.

[0159] The light-shielding film includes: a first light-shielding layer; and a second light-shielding layer disposed on the first light-shielding layer.

[0160] The pattern edge loss area measured by patterning the light-shielding film is 10 nm 2 or less.

[0161] The pattern edge loss area is the area surrounded by a first line, a second line, and the pattern edge contour of the light-shielding pattern film when measuring a transmission electron microscopy (TEM) image of the light-shielding pattern film formed by patterning the light-shielding film and observing the TEM image.

[0162] The first line is an extension line connecting a first point located at 20% of the total height and a second point located at 40% of the total height in the side profile of the light-shielding pattern film when the total height of the light-shielding pattern film is set to 100%.

[0163] The second line is an extension line including a pattern film intersection point and disposed parallel to the upper surface of the light-transmissive substrate.

[0164] The pattern film intersection point is the point where the center line of the pattern film meets the upper surface contour of the light-shielding pattern film.

[0165] The center line of the pattern film is an extension line that passes through the center point of the bottom surface of the above-mentioned light-shielding pattern film, that is, the center point of the pattern film, and is perpendicular to the upper surface of the above-mentioned light-transmitting substrate.

[0166] The light-shielding film 20 can be etched by a resist pattern or an etching mask film disposed on the light-shielding film 20. The side profile of the light-shielding pattern film 23 formed after etching is formed closer to perpendicular to the surface of the light-transmitting substrate 10 disposed below the light-shielding pattern film 23, and the resolution of the photomask 200 can be improved. If the side profile of the light-shielding pattern film 23 is not precisely controlled, the deviation of the critical dimension (CD) of the pattern developed on the semiconductor wafer may further increase.

[0167] This embodiment can provide a light-shielding film 20 that can precisely control the side profile of the light-shielding pattern film 23 formed during patterning by adjusting the pattern edge loss area of the light-shielding film 20.

[0168] Figure 4 It is a schematic diagram for explaining the method of measuring the pattern edge loss area of the light-shielding film. Hereinafter, reference will be made to Figure 4 to explain this embodiment.

[0169] The light-shielding pattern film 23 is formed by patterning the light-shielding film 20.

[0170] After that, the substrate including the above-mentioned light-shielding pattern film 23 is processed into a size of 15 mm in width and 15 mm in length to prepare a sample. After performing a focused ion beam (FIB) process on the surface of the above-mentioned sample, it is disposed in a TEM image measuring device, and thus the TEM image of the above-mentioned sample is measured.

[0171] Exemplarily, the TEM image can be measured by the JEM-2100F HR model of the Japan Electron Optics Laboratory (JEOL).

[0172] Then, in the side profile of the light-shielding pattern film 23 observed from the above-mentioned TEM image, when the total height of the light-shielding pattern film 23 is set to 100%, a first point p1 located at 20% of the total height and a second point p2 located at 40% of the total height are determined, and an extension line connecting the above two points is also determined. The above extension line is defined as the first line L1.

[0173] Determine the pattern film intersection point p i , the pattern film intersection point p iis a point where the center line L0 of the pattern film meets the upper surface contour of the light-shielding pattern film, and the center line L0 of the pattern film is a line passing through the center point of the bottom surface of the light-shielding pattern film 23 observed in the above TEM image, that is, the pattern film center point p c , and is perpendicular to the transparent substrate 10. Determine the extension line including the above pattern film intersection point p i and parallel to the transparent substrate 10. Define the above extension line as the second line L2.

[0174] The pattern edge loss area Ap is defined as the area surrounded by the first line L1, the second line L2, and the pattern edge contour of the light-shielding pattern film 23. Measure the pattern edge loss area Ap from the above TEM image.

[0175] The pattern edge loss area Ap of the light-shielding film 20 can be 10 nm 2 or less. The pattern edge loss area Ap of the light-shielding film 20 can be 8 nm 2 or less. The pattern edge loss area Ap of the light-shielding film 20 can be 6 nm 2 or less. The pattern edge loss area Ap of the light-shielding film 20 can be 0.5 nm 2 or more. In this case, an optical mask 200 that can effectively suppress resolution degradation can be realized from the blank mask 100.

[0176] Composition and film thickness of the light-shielding film

[0177] The light-shielding film 20 may contain at least any one of a transition metal, oxygen, and nitrogen.

[0178] The light-shielding film 20 may include: a first light-shielding layer 21; and a second light-shielding layer 22 located on the first light-shielding layer 21.

[0179] This embodiment can help the light-shielding film 20 exhibit the desired extinction characteristics by controlling the content of each element contained in the second light-shielding layer 22, and can make the side profile of the light-shielding pattern film 25 form an angle close to perpendicular to the transparent substrate when patterning the light-shielding film 20.

[0180] The second light-shielding layer 22 may contain at least any one of a transition metal, oxygen, and nitrogen. The second light-shielding layer 22 may contain 50 atomic% (at%) to 80 atomic% of a transition metal. The second light-shielding layer 22 may contain 55 atomic% to 75 atomic% of a transition metal. The second light-shielding layer 22 may contain 60 atomic% to 70 atomic% of a transition metal.

[0181] The content of the element corresponding to oxygen or nitrogen in the second light-shielding layer 22 may be 10 atomic% to 35 atomic%. The content of the element corresponding to oxygen or nitrogen in the second light-shielding layer 22 may be 15 atomic% to 25 atomic%.

[0182] The second light-shielding layer 22 may contain 5 atomic % to 20 atomic % of nitrogen. The second light-shielding layer 22 may contain 7 atomic % to 13 atomic % of nitrogen.

[0183] In this case, the second light-shielding layer 22 may contribute to making the light-shielding film 20 have excellent light extinction characteristics. In this case, the side profile of the light-shielding pattern film 23 formed by patterning the light-shielding film 20 can be controlled more precisely.

[0184] The first light-shielding layer 21 may contain a transition metal, oxygen, and nitrogen. The first light-shielding layer 21 may contain 30 atomic % to 60 atomic % of the transition metal. The first light-shielding layer 21 may contain 35 atomic % to 55 atomic % of the transition metal. The first light-shielding layer 21 may contain 40 atomic % to 50 atomic % of the transition metal.

[0185] The total content of oxygen and nitrogen in the first light-shielding layer 21 may be 40 atomic % to 70 atomic %. The total content of oxygen and nitrogen in the first light-shielding layer 21 may be 45 atomic % to 65 atomic %. The total content of oxygen and nitrogen in the first light-shielding layer 21 may be 50 atomic % to 60 atomic %.

[0186] The first light-shielding layer 21 may contain 20 atomic % to 40 atomic % of oxygen. The first light-shielding layer 21 may contain 23 atomic % to 33 atomic % of oxygen. The first light-shielding layer 21 may contain 25 atomic % to 30 atomic % of oxygen.

[0187] The first light-shielding layer 21 may contain 5 atomic % to 20 atomic % of nitrogen. The first light-shielding layer 21 may contain 7 atomic % to 17 atomic % of nitrogen. The first light-shielding layer 21 may contain 10 atomic % to 15 atomic % of nitrogen.

[0188] In this case, the first light-shielding layer 21 may contribute to making the light-shielding film 20 have excellent light extinction characteristics and also contribute to improving the etching rate of the light-shielding film 20.

[0189] The above-mentioned transition metal may include at least any one of Cr, Ta, Ti, and Hf. The above-mentioned transition metal may be Cr.

[0190] The film thickness of the first light-shielding layer 21 may be 250 to 650. The film thickness of the first light-shielding layer 21 may be 350 to 600. The film thickness of the first light-shielding layer 21 may be 400 to 550. In this case, the first light-shielding layer 21 can contribute to effectively blocking the exposure light of the light-shielding film 20.

[0191] The film thickness of the second light-shielding layer 22 may be from 30 to 200. The film thickness of the second light-shielding layer 22 may be from 30 to 100. The film thickness of the second light-shielding layer 22 may be from 40 to 80. In this case, the second light-shielding layer 22 can improve the extinction characteristics of the light-shielding film 20 and help to further precisely control the side profile of the light-shielding pattern film 23.

[0192] The film thickness ratio of the second light-shielding layer 22 to the film thickness of the first light-shielding layer 21 may be from 0.05 to 0.3. The above film thickness ratio may be from 0.07 to 0.25. The above film thickness ratio may be from 0.1 to 0.2. In this case, the light-shielding film 20 can have sufficient extinction characteristics and can form a side profile that is substantially perpendicular to the surface of the light-transmitting substrate when patterning is implemented.

[0193] Other thin films

[0194] Figure 5 FIG. is a schematic diagram for explaining a blank mask according to another embodiment of the present specification. The above will be referred to Figure 5 to explain the blank mask of the present embodiment.

[0195] The phase shift film 30 may be located between the light-transmitting substrate 10 and the light-shielding film 20. The phase shift film 30 is for attenuating the intensity of the exposure light that penetrates the above phase shift film 30 and substantially suppressing the diffracted light generated at the pattern edge by adjusting the phase difference.

[0196] For light with a wavelength of 193 nm, the phase shift film 30 may have a phase difference of 170° to 190°. For light with a wavelength of 193 nm, the phase shift film 30 may have a phase difference of 175° to 185°. For light with a wavelength of 193 nm, the phase shift film 30 may have a transmittance of 3% to 10%. For light with a wavelength of 193 nm, the phase shift film 30 may have a transmittance of 4% to 8%. In this case, the resolution of the photomask 200 including the above phase shift film 30 can be improved.

[0197] The phase shift film 30 may contain a transition metal and silicon. The phase shift film 30 may contain a transition metal, silicon, oxygen, and nitrogen. The above transition metal may be molybdenum.

[0198] The description of the light-transmitting substrate 10 and the light-shielding film 20 respectively repeats the content described above, so the description thereof will be omitted.

[0199] A hard mask (not shown) may be located on the light-shielding film 20. When patterning and etching the light-shielding film 20, the hard mask can be used as an etching mask film. The hard mask may contain silicon, nitrogen, and oxygen.

[0200] Photomask

[0201] Figure 6 It is a schematic diagram for explaining a photomask according to another embodiment of the present specification. Reference will be made to the above Figure 6 to explain the photomask of this embodiment.

[0202] The photomask 200 according to another embodiment of the present specification includes: a light-transmissive substrate 10; and a light-shielding pattern film 25 located on the light-transmissive substrate 10.

[0203] The light-shielding pattern film 25 contains at least any one of a transition metal, oxygen, and nitrogen.

[0204] The light-shielding pattern film 25 includes: a first light-shielding layer 21; and a second light-shielding layer 22 disposed on the first light-shielding layer 21.

[0205] The Rd value of the light-shielding pattern film 25 in the following formula 1 is 0.4 to 0.8.

[0206] [Formula 1]

[0207]

[0208] In the above formula 1, the er1 value is the etching rate of the first light-shielding layer 21 measured by etching with argon gas.

[0209] The er2 value is the etching rate of the second light-shielding layer 22 measured by etching with argon gas.

[0210] The light-shielding pattern film 25 can be formed by patterning the light-shielding film 20 of the blank photomask 100 described above.

[0211] The method for measuring the Rd value of the light-shielding pattern film 25 is the same as the method for measuring the Rd value of the light-shielding film 20 in the blank photomask 100.

[0212] The pattern edge loss area of the light-shielding pattern film 25 can be 10 nm 2 or less.

[0213] Except for omitting the process of patterning the light-shielding film 20, the method for measuring the pattern edge loss area of the light-shielding pattern film 25 is the same as the method for measuring the pattern edge loss area of the light-shielding film 20.

[0214] The PDo value of the light-shielding pattern film 25 in the following formula 3 can be less than 0.05.

[0215] [Formula 3]

[0216] PDo = PBo - PPo

[0217] In the above formula 3, the PBo value is the optical density of the light-shielding pattern film 25 measured by irradiating exposure light with a wavelength of 193 nm.

[0218] The above PPo value is the average value of the optical density of the light-shielding pattern film measured by irradiating the measurement area of the light-shielding pattern film 25 with exposure light having a wavelength of 193 nm. When observing the light-shielding pattern film 25 from above, the measurement area corresponds to the area from one edge of the light-shielding pattern film 25 to the position spaced 4 nm in the inner direction of the light-shielding pattern film 25.

[0219] The above one edge refers to the edge formed by etching among the edges of the light-shielding pattern film 25.

[0220] The measurement methods of the PDo value, PBo value, and PPo value of the light-shielding pattern film 25 are the same as the measurement methods of the Do value, Bo value, and Po value of the light-shielding film 20, respectively. However, the process of patterning the light-shielding film is omitted when measuring the PDo value, PBo value, and PPo value of the light-shielding pattern film 25. In addition, when measuring the PBo value, the surface to be measured is the surface of the light-shielding pattern film 25, rather than the surface of the light-shielding film before patterning.

[0221] The descriptions of the physical properties, components, and structure, etc. of the light-shielding pattern film 25 are repeated with those of the light-shielding film of the blank mask, and thus the descriptions thereof will be omitted.

[0222] Manufacturing method of the light-shielding film

[0223] The manufacturing method of the blank mask according to an embodiment of the present specification may include a preparation step, in which a transparent substrate, a sputtering target, and a magnet are disposed in a sputtering chamber.

[0224] The manufacturing method of the blank mask according to an embodiment of the present specification may include a film-forming step, in which an atmosphere gas is injected into the sputtering chamber, the rotation speed of the magnet is controlled, and electric power is applied to the sputtering target to form a light-shielding film on the transparent substrate.

[0225] The manufacturing method of the blank mask according to an embodiment of the present specification may include a heat treatment step, in which heat treatment is performed at a temperature of 150 °C to 330 °C for 5 minutes to 30 minutes.

[0226] The manufacturing method of the blank mask according to an embodiment of the present specification may include a cooling step of cooling the light-shielding film that has undergone the above heat treatment step.

[0227] The manufacturing method of the blank mask according to an embodiment of the present specification may include a stabilization step, in which the blank mask that has undergone the above cooling step is stabilized at a temperature of 30 °C to 50 °C for 1 minute to 5 minutes.

[0228] The film-forming step may include: a first light-shielding layer film-forming process of forming a first light-shielding layer on a light-transmitting substrate; and a second light-shielding layer film-forming process of forming a second light-shielding layer on the first light-shielding layer.

[0229] In the preparation step, the target for forming the light-shielding film may be selected in consideration of the composition of the light-shielding film. As the sputtering target, a target containing a transition metal may be applied. The sputtering target may be two or more targets including a target containing a transition metal. The target containing a transition metal may contain 90 atomic% or more of a transition metal. The target containing a transition metal may contain 95 atomic% or more of a transition metal. The target containing a transition metal may contain 99 atomic% of a transition metal.

[0230] The transition metal may include at least any one of Cr, Ta, Ti, and Hf. The transition metal may include Cr.

[0231] The content regarding the light-transmitting substrate disposed in the sputtering chamber is repeated with the above content, and thus the description will be omitted.

[0232] In the preparation step, a magnet may be disposed in the sputtering chamber. The magnet may be disposed on the surface opposite to the surface where sputtering occurs in the sputtering target.

[0233] In the film-forming step of the light-shielding film, different film-forming process conditions may be adopted when forming each layer included in the light-shielding film. In particular, considering the extinction characteristics and etching characteristics of the light-shielding film, etc., different conditions may be adopted for each layer, such as the composition of the atmosphere gas, the pressure in the chamber, the power applied to the sputtering target, the rotation speed of the magnet, the film-forming time, the rotation speed of the substrate, etc.

[0234] The atmosphere gas may include an inert gas, a reactive gas, and a sputtering gas. The inert gas is a gas containing elements that do not constitute the thin film to be formed. The reactive gas is a gas containing elements that constitute the thin film to be formed. The sputtering gas is a gas that is ionized in a plasma atmosphere and collides with the target. The inert gas may include helium. The reactive gas may include a gas containing nitrogen. For example, the gas containing nitrogen may be N2, NO, NO2, N2O, N2O3, N2O4, N2O5, etc. The reactive gas may include a gas containing oxygen. For example, the gas containing oxygen may be O2, CO2, etc. The reactive gas may include a gas containing nitrogen and a gas containing oxygen. The reactive gas may include a gas containing both nitrogen and oxygen. For example, the gas containing both nitrogen and oxygen may be NO, NO2, N2O, N2O3, N2O4, N2O5, etc.

[0235] The sputtering gas may be Ar gas.

[0236] As a power source for applying electric power to the sputtering target, a DC power source can be used, or an RF power source can also be used.

[0237] In the film formation step of the light-shielding film, the rotation speed of the magnet can be adjusted. The rotation speed of the magnet may affect the distribution area of the plasma formed in the sputtering chamber. Specifically, as the rotation speed of the magnet increases, the plasma tends to form around the sputtering target, and as the rotation speed of the magnet decreases, the plasma tends to form around the light-transmitting substrate.

[0238] The density of the film to be formed can vary depending on the formation position of the plasma formed in the sputtering chamber. As the plasma forms closer to the periphery of the sputtering target, the number of collisions between argon ions and one side of the sputtering target relatively increases, and the film tends to be formed relatively densely. When controlling the rotation speed of the magnet in consideration of the above plasma characteristics, the density of the first light-shielding layer and the second light-shielding layer formed in the light-shielding film can be relatively easily controlled separately.

[0239] During the film formation of the first light-shielding layer, the electric power applied to the sputtering target can be 1.5 kW to 2.5 kW. During the film formation of the first light-shielding layer, the electric power applied to the sputtering target can be 1.6 kW to 2 kW.

[0240] During the film formation of the first light-shielding layer, the flow rate ratio of the reactive gas to the flow rate of the inert gas with respect to the atmosphere gas can be 1.5 to 3. The above flow rate ratio can be 1.8 to 2.7. The above flow rate ratio can be 2 to 2.5.

[0241] In the reactive gas, the ratio of the nitrogen content to the oxygen 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.

[0242] In this case, the first light-shielding layer can help the light-shielding film to have sufficient light extinction characteristics. In addition, by controlling the etching characteristics of the first light-shielding layer, it can help the side profile of the light-shielding pattern film after patterning to have a shape close to perpendicular to the surface of the light-transmitting substrate.

[0243] During the film formation of the first light-shielding layer, the rotation speed of the magnet can be 90 rpm to 140 rpm. During the film formation of the first light-shielding layer, the rotation speed of the magnet can be 100 rpm to 120 rpm. In this case, it can help to increase the etching speed of the first light-shielding layer.

[0244] The film formation time of the first light-shielding layer can be from 200 seconds to 300 seconds. The film formation time of the first light-shielding layer can be from 210 seconds to 240 seconds. In this case, the first light-shielding layer can help the light-shielding film to have sufficient light extinction characteristics.

[0245] During the film formation process of the second light-shielding layer, the power applied to the sputtering target can be from 1 kW to 2 kW. During the film formation process of the second light-shielding layer, the power applied to the sputtering target can be from 1.2 kW to 1.7 kW. In this case, it can help the second light-shielding layer to have a density within a preset range.

[0246] During the film formation process of the second light-shielding layer, the flow rate ratio of the reactive gas to the flow rate of the inert gas with respect to the atmosphere gas can be from 0.3 to 0.8. The above flow rate ratio can be from 0.4 to 0.6.

[0247] During the film formation process of the second light-shielding layer, in the reactive gas, the ratio of the oxygen content to the nitrogen content can be 0.3 or less. In the reactive gas, the ratio of the oxygen content to the nitrogen content can be 0.1 or less. In the reactive gas, the ratio of the oxygen content to the nitrogen content can be 0.001 or more.

[0248] In this case, by controlling the density, etc. of the second light-shielding layer, the side surface of the light-shielding pattern film formed by patterning can have a profile close to being perpendicular to the surface of the light-transmitting substrate.

[0249] During the film formation process of the second light-shielding layer, the rotation speed of the magnet can be adjusted. When controlling the rotation speed of the magnet from the perspective of only suppressing unnecessary etching that may occur on the side surface of the second light-shielding layer in the light-shielding pattern film when patterning the light-shielding film, the sputtering particles generated by the sputtering target do not deposit on the surface of the film formation object, but may be redeposited on the surface of the above sputtering target. The redeposited sputtering particles may act as a particle source, resulting in a decrease in the resolution of the blank mask. In this embodiment, during the film formation process of the second light-shielding layer, by controlling the rotation speed of the magnet within a preset range, the side surface profile of the light-shielding pattern film can be precisely controlled when patterning the light-shielding film, and the formation of particles can also be effectively suppressed.

[0250] During the film formation process of the second light-shielding layer, the rotation speed of the magnet can be from 100 rpm to 150 rpm. During the film formation process of the second light-shielding layer, the rotation speed of the magnet can be from 110 rpm to 140 rpm. In this case, when patterning the light-shielding film, the side surface profile of the light-shielding pattern film can be precisely controlled, and the pattern resolution degradation caused by particles can be suppressed.

[0251] The film formation time of the second light-shielding layer can be from 10 seconds to 30 seconds. The film formation time of the second light-shielding layer can be from 15 seconds to 25 seconds. In this case, the second light-shielding layer can help the side surface of the patterned light-shielding film to form an angle close to perpendicular to the surface of the light-transmitting substrate.

[0252] In the heat treatment step, the light-shielding film that has completed the film formation step can be heat-treated. Specifically, the substrate on which the light-shielding film has been formed can be placed in a heat treatment chamber and then heat-treated.

[0253] In the heat treatment step, the atmosphere temperature can be from 150 °C to 300 °C. The above atmosphere temperature can be from 170 °C to 280 °C. The above atmosphere temperature can be from 200 °C to 250 °C.

[0254] In the heat treatment step, the heat treatment time can be from 5 minutes to 25 minutes. The above heat treatment time can be from 10 minutes to 20 minutes. In this case, the stress formed in the light-shielding film can be effectively reduced.

[0255] The blank mask can perform a cooling step within 2 minutes after the heat treatment step. In this case, the grain growth of the transition metal contained in the light-shielding film due to heating can be suppressed.

[0256] In the cooling step, the light-shielding film can be cooled using a cooling plate. Specifically, a cooling plate adjusted to a preset cooling temperature can be arranged on the substrate side of the blank mask that has completed the heat treatment step, thereby cooling the blank mask. In the cooling step, the cooling rate of the blank mask can be controlled by adjusting the distance between the blank mask and the cooling plate.

[0257] In the cooling step, the cooling temperature applied to the cooling plate can be from 10 °C to 40 °C. The above cooling temperature can be from 20 °C to 30 °C.

[0258] The cooling step can be performed for 5 minutes to 20 minutes. The cooling step can be performed for 10 minutes to 15 minutes.

[0259] In the cooling step, the separation distance between the blank mask and the cooling plate can be from 0.01 mm to 30 mm. The above separation distance can be from 0.05 mm to 5 mm. The above separation distance can be from 0.1 mm to 2 mm.

[0260] In the cooling step, the cooling rate of the blank mask can be from 0.45 °C / s to 1 °C / s. The above cooling rate can be from 0.5 °C / s to 0.8 °C / s.

[0261] In this case, damage to the light-shielding film caused by cooling can be substantially and significantly suppressed, and a decrease in the density of each layer, particularly the second light-shielding layer, due to grain growth of transition metals contained in the light-shielding film after heat treatment can be effectively suppressed.

[0262] In the stabilization step, the blank mask that has undergone the cooling step can be stabilized. In the case of a blank mask that has undergone the cooling step, significant damage may be caused to the blank mask due to a sharp change in temperature. To prevent this from happening, a stabilization step may be required.

[0263] The method for stabilizing the blank mask that has undergone the cooling step can be various. As an example, after separating the blank mask that has undergone the cooling step from the cooling plate, it can be placed in the atmosphere at room temperature for a predetermined time. As another example, the blank mask that has undergone the cooling step can be separated from the cooling plate and then stabilized at 30°C to 50°C for 1 minute to 5 minutes. At this time, the blank mask can be rotated at a rotation speed of 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 sprayed onto the blank mask that has undergone the cooling step at a flow rate of 5 L / min to 10 L / min 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.

[0264] Manufacturing method of semiconductor elements

[0265] A method for manufacturing a semiconductor device according to another embodiment of the present specification includes: a preparation step for arranging a light source, a photomask, and a semiconductor wafer coated with a resist film; an exposure step for selectively transmitting light incident from the light source through the photomask onto the semiconductor wafer and emitting the light; and a development step for developing a pattern on the semiconductor wafer.

[0266] The photomask includes: a light-transmitting substrate; and a light-shielding pattern film disposed on the light-transmitting substrate.

[0267] The light-shielding pattern film contains at least any one of a transition metal, oxygen, and nitrogen.

[0268] The light-shielding pattern film includes: a first light-shielding layer; and a second light-shielding layer disposed on the first light-shielding layer.

[0269] The Rd value of the light-shielding pattern film represented by the following formula 1 is 0.4 to 0.8.

[0270] [Formula 1]

[0271]

[0272] In the above formula (1), the above er1 value is the etching rate of the above first light-shielding layer etched and measured using argon gas.

[0273] The above er2 value is the etching rate of the above second light-shielding layer etched and measured using argon gas.

[0274] In the preparation step, the light source is a device capable of generating exposure light rays with a short wavelength. The exposure light rays can be light with a wavelength of 200 nm or less. The exposure light rays can be ArF light with a wavelength of 193 nm.

[0275] A lens can be additionally disposed between the photomask and the semiconductor wafer. The lens has the function of reducing the shape of the circuit pattern on the photomask and transferring it onto the semiconductor wafer. As the lens, as long as it is a lens commonly applied to the ArF semiconductor wafer exposure process, there is no limitation. For example, the above lens can be a lens made of calcium fluoride (CaF2).

[0276] In the exposure step, the exposure light rays can be selectively transmitted onto the semiconductor wafer through the photomask. In this case, chemical denaturation may occur in the portion of the resist film where the exposure light rays are incident.

[0277] In the development step, the semiconductor wafer that has completed the exposure step can be treated with a developing solution, thereby developing a pattern on the semiconductor wafer. When the coated resist film is a positive resist, the portion of the resist film where the exposure light rays are incident may be dissolved by the developing solution. When the coated resist film is a negative resist, the portion of the resist film where the exposure light rays are not incident may be dissolved by the developing solution. Through the developing solution treatment, the resist film is formed into a resist pattern. A pattern can be formed on the semiconductor wafer by using the above resist pattern as a mask.

[0278] The description of the photomask repeats the previous content, so the description will be omitted.

[0279] Hereinafter, specific embodiments will be described in more detail.

[0280] Manufacturing Example: Film Formation of the Light-Shielding Film

[0281] Example 1: In the chamber of a DC sputtering device, a light-transmitting substrate made of quartz with a width of 6 inches, a length of 6 inches, and a thickness of 0.25 inches was disposed. 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. A magnet was provided on the back of the above chromium target.

[0282] Thereafter, an atmosphere gas mixed with 21 vol% of Ar, 11 vol% of N2, 32 vol% of CO2, and 36 vol% of He was introduced into the chamber, 1.85 kW of electric power was applied to the sputtering target, the rotation speed of the magnet was set to 113 rpm, and a sputtering process was performed for 250 seconds to form a first light-shielding layer.

[0283] After forming the first light-shielding layer, an atmosphere gas mixed with 57 vol% of Ar and 43 vol% of N2 was introduced into the chamber, 1.5 kW of electric power was applied to the sputtering target, the rotation speed of the magnet was set to 113 rpm, and a sputtering process was performed for 25 seconds to fabricate a sample of a blank mask having a second light-shielding layer formed thereon.

[0284] The sample after forming the second light-shielding layer was placed in a heat treatment chamber. Thereafter, heat treatment was performed at an atmosphere temperature of 250 °C for 15 minutes. The blank mask that had completed the heat treatment was taken out from the heat treatment chamber, and the blank mask was rotated at a rotation speed of 30 rpm at an atmosphere temperature of 40 °C for 2 minutes to stabilize it.

[0285] A cooling plate with a cooling temperature of 10 °C to 40 °C was provided on the substrate side of the stabilized blank mask. The separation distance between the substrate of the blank mask and the cooling plate was 0.1 mm. The cooling step was carried out for 5 minutes to 20 minutes.

[0286] Example 2: A blank mask sample was fabricated under the same conditions as in Example 1. However, when forming the first light-shielding layer, a gas mixed with 19 vol% of Ar, 11 vol% of N2, 36 vol% of CO2, and 34 vol% of He was used as the atmosphere gas.

[0287] Example 3: A blank mask sample was fabricated under the same conditions as in Example 1. However, when forming the first light-shielding layer, a gas mixed with 17 vol% of Ar, 24 vol% of N2, 29 vol% of CO2, and 30 vol% of He was used as the atmosphere gas. In addition, when cooling the blank mask sample, the separation distance between the substrate surface of the blank mask and the cooling plate was set to 2 mm.

[0288] Example 4: A blank mask sample was fabricated under the same conditions as in Example 2. However, when forming the second light-shielding layer, the rotation speed of the magnet was set to 127 rpm. In addition, when cooling the blank mask sample, the separation distance between the substrate of the blank mask and the cooling plate was set to 2 mm.

[0289] Example 5: A blank mask sample was fabricated under the same conditions as in Example 4, except that when forming the first light-shielding layer, the rotation speed of the magnet was set to 131 rpm.

[0290] Example 6: A blank mask sample was fabricated under the same conditions as in Example 2, except that when cooling the blank mask sample, the separation distance between the substrate surface of the blank mask and the cooling plate was set to 5 mm.

[0291] Comparative Example 1: A blank mask sample was fabricated under the same conditions as in Example 1, except that when forming the second light-shielding layer, a gas mixture of 44 vol% Ar and 56 vol% N2 was used as the atmosphere gas.

[0292] Comparative Example 2: A blank mask sample was fabricated under the same conditions as in Example 2, except that when forming the second light-shielding layer, the rotation speed of the magnet was set to 89 rpm.

[0293] Comparative Example 3: A blank mask sample was fabricated under the same conditions as in Example 2, except that when cooling the blank mask sample, the separation distance between the substrate surface of the blank mask and the cooling plate was set to 10 mm.

[0294] Comparative Example 4: A blank mask sample was fabricated under the same conditions as in Example 2, except that when cooling the blank mask sample, the separation distance between the substrate surface of the blank mask and the cooling plate was set to 20 mm.

[0295] The film formation, heat treatment, and cooling conditions for each example and comparative example are shown in Table 1 below.

[0296] Evaluation Example: Measurement of the Rd value of the light-shielding film

[0297] Samples of each example and comparative example were processed into a size of 15 mm in width and 15 mm in length. After the surface of the processed sample was subjected to Focused Ion Beam (FIB) treatment, it was placed inside a JEM-2100F HR model device of Japan Electron Optics Laboratory (JEOL), and the TEM image of the above sample was measured. The thicknesses of the first light-shielding layer and the second light-shielding layer were calculated respectively from the above TEM images.

[0298] Afterwards, the above sample was etched with argon gas, and the etching times of the first light-shielding layer and the second light-shielding layer were measured respectively. The above sample was placed in a K-Alpha model device of Thermo Fisher Scientific Inc. in the United States, and the region with a width of 4 mm and a length of 2 mm at the center of the above sample was etched with argon gas, thereby measuring the etching time of each layer. When measuring the etching time of each layer, the vacuum degree in the measuring device was 1.0×10 -8 mbar, the X-ray source was Monochromator Al Kα (1486.6 eV), the anode power was 72 W, the anode voltage was 12 kV, and the voltage of the argon ion beam was 1 kV.

[0299] The er1 value, er2 value, and Rd value were calculated from the measured thicknesses and etching rates of the first light-shielding layer and the second light-shielding layer. The er1 value, er2 value, and Rd value measured from each example and comparative example are shown in Table 2 below.

[0300] Evaluation example: Measurement of the optical properties of the light-shielding film

[0301] From the surface of the light-shielding film of the samples of each example and comparative example, the optical density, that is, the Bo value, and the transmittance for the exposure light with a wavelength of 193 nm were measured using the MGPro model of NANO-VIEW Co., Ltd. in Korea.

[0302] Afterwards, a light-shielding pattern film was formed by patterning the light-shielding film. The MG Pro model of NANO-VIEW Co., Ltd. in Korea was used to irradiate the measurement region of the above light-shielding pattern film with exposure light having a wavelength of 193 nm to measure the Po value. When observing the above light-shielding pattern film from above, the measurement region corresponded to the region from one edge formed by patterning of the above light-shielding pattern film to the position 4 nm away in the inner direction of the above light-shielding pattern film.

[0303] The Do value was calculated from the measured Bo value and Po value.

[0304] The Do value, Bo value, Po value, and transmittance for light with a wavelength of 193 nm measured in each example and comparative example are shown in Table 2 below.

[0305] Evaluation example: Measurement of the etching characteristics of the light-shielding film

[0306] The thickness of the light-shielding film was measured by measuring the TEM images of the light-shielding films contained in the samples of each of the examples and comparative examples. The samples were processed into a size of 15 mm in width and 15 mm in length. After performing focused ion beam (FIB) processing on the surface of the processed samples, they were placed inside a JEM-2100F HR model device of Japan Electron Optics Laboratory (JEOL), and the TEM images of the samples were measured. The thickness of the light-shielding film was calculated from the above TEM images.

[0307] After that, the etching time of the light-shielding film with respect to chlorine-based gas was measured. As the above chlorine-based gas, a gas containing 90 vol% to 95 vol% of chlorine gas and 5 vol% to 10 vol% of oxygen gas was used. The etching rate of the light-shielding film with respect to chlorine-based gas was calculated from the thickness of the above light-shielding film and the etching time of the light-shielding film.

[0308] The measured values of the etching rates of each of the examples and comparative examples are shown in Table 2 below.

[0309] Evaluation example: Measurement of the pattern edge loss area of the light-shielding film

[0310] A light-shielding pattern film was formed by patterning the light-shielding films of the samples of each of the examples and comparative examples. After that, the substrate including the above light-shielding pattern film was processed into a size of 15 mm in width and 15 mm in length. After performing focused ion beam (FIB) processing on the surface of the above sample, it was placed inside a JEM-2100F HR model device of Japan Electron Optics Laboratory (JEOL), and the TEM image of the above sample was measured.

[0311] Then, in the side profile of the light-shielding pattern film observed in the above TEM image, when the total height of the light-shielding pattern film was set to 100%, the points located at 20% of the total height and the points located at 40% of the total height were determined, and the extension line connecting the above two points, that is, the first line, was also determined.

[0312] By determining the intersection point of the straight line passing through the central portion of the light-shielding pattern film observed in the above TEM image and the upper surface profile, the extension line including the above intersection point and arranged in parallel with the light-transmitting substrate, that is, the second line, was determined.

[0313] The area surrounded by the first line, the second line, and the profile of the light-shielding pattern film, that is, the pattern edge loss area, was measured from the above TEM image.

[0314] The pattern edge loss areas measured in each of the examples and comparative examples are shown in Table 2 below.

[0315] [Table 1]

[0316]

[0317] [Table 2]

[0318]

[0319] In Table 2 above, the Rd values of Examples 1 to 6 are from 0.4 to 0.8. On the other hand, the Rd values of Comparative Example 1 and Example 2 are less than 0.4 or greater than 0.8.

[0320] Regarding the Do value, the Do values of Examples 1 to 6 are less than 0.05. On the other hand, the Do values of all the comparative examples are 0.05 or more.

[0321] Regarding the transmittance, the transmittances of Examples 1 to 6 are 1.55% or less. On the other hand, the transmittance of Comparative Example 2 is 1.7% or more.

[0322] Regarding the etching rate, the etching rates of all the examples and comparative examples are above.

[0323] Regarding the pattern edge loss area, the pattern edge loss areas of Examples 1 to 6 are 8 nm 2 or less. On the other hand, the pattern edge loss areas of all the comparative examples are 8.5 nm 2 or more.

[0324] The preferred embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto. Various modifications and improvements made by those of ordinary skill in the technical field to which the present invention pertains, using the basic concepts of the present invention defined in the appended claims, also fall within the scope of the present invention.

Claims

1. A blank mask, wherein, Comprising: A light-transmitting substrate; And A light-shielding film disposed on the light-transmitting substrate, The light-shielding film contains at least any one of a transition metal, oxygen, and nitrogen, The light-shielding film includes a first light-shielding layer and a second light-shielding layer disposed on the first light-shielding layer, The Rd value of the light-shielding film in the following formula 1 is 0.4 to 0.8, [Formula 1] In the above formula 1, The er1 value is the etching rate of the first light-shielding layer measured by etching with argon, The er2 value is the etching rate of the second light-shielding layer measured by etching with argon, The er2 value is to 2. The blank mask according to claim 1, wherein, The er1 value is above.

3. The blank mask according to claim 1, wherein, The Do value of the light-shielding film in the following formula 2 is less than 0.05, [Formula 2] Do = Bo - Po In the above formula 2, The Bo value is the optical density of the light-shielding film measured by irradiating exposure light with a wavelength of 193 nm, The Po value is the optical density of the light-shielding pattern film measured by irradiating exposure light with a wavelength of 193 nm to the measurement area of the light-shielding pattern film. The light-shielding pattern film is formed by patterning the light-shielding film. When observing the light-shielding pattern film from above, the measurement area corresponds to the area from one edge formed by patterning of the light-shielding pattern film to a position 4 nm away in the inner direction of the light-shielding pattern film.

4. The blank mask according to claim 1, wherein, The transition metal includes at least any one of Cr, Ta, Ti, and Hf.

5. The blank mask according to claim 1, wherein, The etching rate of the light-shielding film for chlorine-based gas is or more.

6. A blank mask, wherein, Comprising: A light-transmitting substrate; ​ ​ ​ ​ ​ ​ ​ ​ ​ The er2 value is to The light-shielding film is patterned to form a light-shielding pattern film, and the pattern edge loss area of the measured light-shielding pattern film is 10 nm 2 Hereinafter, ​ ​ ​ ​ ​ 7. A photomask, wherein, ​ ​ ​ A light-shielding pattern film, disposed on the transparent substrate, The light-shielding pattern film contains at least any one of a transition metal, oxygen, and nitrogen, The light-shielding pattern film includes a first light-shielding layer and a second light-shielding layer disposed on the first light-shielding layer, The Rd value of the light-shielding pattern film in Formula 1 below is 0.4 to 0.8, [Formula 1] In the above Formula 1, The er1 value is the etching rate of the first light-shielding layer etched and measured using argon gas, The er2 value is the etching rate of the second light-shielding layer etched and measured using argon gas, The er2 value is to 8. The photomask according to claim 7, wherein When observing the cross-section of the light-shielding pattern film, the pattern edge loss area of the light-shielding pattern film measured on the cross-section is 10 nm 2 Hereinafter, The pattern edge loss area is the area surrounded by a first line, a second line, and the pattern edge contour of the light-shielding pattern film when measuring the transmission electron microscope image of the light-shielding pattern film and observing the transmission electron microscope image, The first line is, in the side profile of the light-shielding pattern film, when the total height of the light-shielding pattern film is set to 100%, the extension line connecting a first point at 20% of the total height and a second point at 40% of the total height, The second line is the extension line including the pattern film intersection point and disposed parallel to the upper surface of the transparent substrate, The pattern film intersection point is the point where the pattern film center line meets the upper surface contour of the light-shielding pattern film, The pattern film center line is the extension line passing through the pattern film center point which is the center point of the bottom surface of the light-shielding pattern film and perpendicular to the upper surface of the transparent substrate.

9. A method for manufacturing a semiconductor device, wherein, Including: A preparation step for disposing a light source, a photomask, and a semiconductor wafer coated with a resist film; An exposure step of selectively transmitting the light incident from the light source through the photomask onto the semiconductor wafer and emitting the light; And A developing step of developing a pattern on the semiconductor wafer, The photomask includes: a transparent substrate; And a light-shielding pattern film, disposed on the transparent substrate, The light-shielding pattern film contains at least any one of a transition metal, oxygen, and nitrogen, The light-shielding pattern film includes a first light-shielding layer and a second light-shielding layer disposed on the first light-shielding layer, The Rd value of the light-shielding pattern film in Formula 1 below is 0.4 to 0.8, [Formula 1] In the above Formula 1, The er1 value is the etching rate of the first light-shielding layer etched and measured using argon gas, The er2 value is the etching rate of the second light-shielding layer etched and measured using argon gas, The er2 value is to

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