Conductive film-equipped substrate, multilayer reflective film-equipped substrate, reflective mask blank, reflective mask, and method for manufacturing semiconductor device

Abstract

Provided is a conductive film-equipped substrate capable of inhibiting deformation of a mask substrate caused by stress change in a conductive film even when a reflective mask manufactured by applying the conductive film-equipped substrate is exposed to an exposure environment. The conductive film-equipped substrate has: a substrate having a first main surface; and a conductive film that is formed on the first main surface and contains hydrogen. The conductive film is a single layer film or a lamination film including a lower layer and an upper layer formed on the lower layer. The single layer film and the lower layer contain a metal, and nitrogen or boron. The upper layer contains a metal and oxygen. When an analysis of the conductive film is conducted in an arbitrarily defined 124 μm square region within a 5 cm square including the center of the substrate by the dynamic secondary ion mass spectrometry under conditions in which the primary ion species is Cs+, the primary acceleration voltage is 3.0 kV, and the primary ion current is 25 nA, the secondary ion intensity of detected hydrogen is 1.0×102 cps or more.

Description

Substrate with conductive film, substrate with multilayer reflective film, reflective mask blank, reflective mask, and method for manufacturing semiconductor device

[0001] The present disclosure relates to a substrate with a conductive film, a substrate with a multilayer reflective film, a reflective mask blank, a reflective mask, and a method for manufacturing a semiconductor device.

[0002] In general, in the manufacturing process of semiconductor devices, fine patterns are formed using photolithography. Furthermore, to form these fine patterns, a number of transfer masks, also known as photomasks, are typically used. These transfer masks are generally formed by providing a fine pattern made of a metal thin film or the like on a glass substrate. Electron beam lithography is used to manufacture these transfer masks.

[0003] In the manufacture of a transfer mask using electron beam lithography, a mask blank is used that has a thin film (e.g., a light-shielding film) for forming a transfer pattern (mask pattern) on a substrate such as a glass substrate. The manufacture of a transfer mask using this mask blank involves a patterning process, a development process, an etching process, and a peeling / removal process. In the patterning process, a desired pattern is drawn on a resist film formed on the mask blank. In the development process, after drawing, the resist film is developed to form the desired resist pattern. In the etching process, the thin film is etched using the resist pattern as a mask. In the peeling / removal process, the remaining resist pattern is peeled / removed. More specifically, in the development process, the desired pattern is drawn on the resist film formed on the mask blank, and then a developer is supplied to dissolve portions of the resist film that are soluble in the developer, thereby forming a resist pattern. In the etching process, the resist pattern is used as a mask to remove exposed portions of the thin film where the resist pattern is not formed by dry etching or wet etching, thereby forming the desired mask pattern on the substrate. In this way, a transfer mask having a desired mask pattern (fine pattern) formed on the substrate is completed.

[0004] Known types of transfer masks include a binary mask having a light-shielding film pattern made of a chromium-based material on a conventional substrate, and a phase-shift mask.

[0005] Furthermore, in recent years, with the increasing integration density of semiconductor devices in the semiconductor industry, there has been a demand for finer patterns that exceed the transfer limit of conventional lithography methods using ultraviolet light. To enable the formation of such fine patterns, there is EUV lithography, an exposure technology using extreme ultraviolet (EUV) light. Here, EUV light refers to light in the wavelength band of the soft X-ray region or the vacuum ultraviolet region, and light with a wavelength of approximately 0.2 to 100 nm. In this disclosure, EUV light refers to light including light with a wavelength of 13.5 nm, and can be light with a wavelength of 13 to 14 nm, more specifically, light with a wavelength of 13.5 nm. In this disclosure, light includes not only visible light but also electromagnetic waves. A reflective mask is a transfer mask used in this EUV lithography. Such a reflective mask has a multilayer reflective film formed on a substrate that reflects EUV light, which is the exposure light, and an absorber film that absorbs EUV light formed in a pattern on the multilayer reflective film. The reflective mask used in EUV lithography is also called an EUV mask.

[0006] A reflective mask is supported by an electrostatic chuck in an exposure tool during pattern transfer onto a semiconductor substrate, for example. Meanwhile, a reflective mask blank or a substrate (mask blank substrate, mask substrate) used in a reflective mask is made of an insulating glass substrate or the like. Therefore, a conductive film (rear conductive film) is formed on the rear surface of the mask blank substrate or mask substrate. As a conventional technique, for example, Patent Document 1 discloses a mask substrate having a rear coating (conductive film) made of a material with a higher dielectric constant than the substrate, such as silicon, molybdenum, chromium, chromium oxynitride, or TaSi. Furthermore, Patent Document 2 discloses a reflective mask blank for EUV lithography on which a conductive film made of a material containing tantalum and substantially no hydrogen is formed.

[0007] JP-T-2003-501823 A JP-A-2013-225662

[0008] In a reflective mask blank, as time passes after production, the film stress of the conductive film changes with time, causing a change in the substrate flatness, which gives rise to a new problem in that it is difficult to guarantee the pattern position accuracy in the EUV mask.

[0009] The above-mentioned Patent Document 2 presumes that the reason why the compressive stress of the conductive film immediately after deposition on the glass substrate increases over time is because hydrogen contained in the glass substrate is gradually absorbed into the conductive film over time. Based on this presumption, the above-mentioned Patent Document 2 discloses providing a hydrogen penetration suppression film between the glass substrate and the conductive film in order to suppress fluctuations in substrate flatness due to penetration of hydrogen contained in the glass substrate into the conductive film.

[0010] However, even if the penetration of hydrogen contained in the glass substrate into the conductive film is suppressed, hydrogen in the exposure environment may penetrate into the conductive film during EUV mask exposure. In recent years, exposure tools with larger numerical apertures (NA) in the projection optical system have been considered to improve resolution performance. The shift to such exposure tools increases exposure output, accelerating the penetration of the generated hydrogen plasma into the conductive film, which can deform the mask substrate and cause misalignment of the transfer position during exposure.

[0011] Therefore, the present disclosure has been made in consideration of such problems, and its object is, first, to provide a substrate with a conductive film that can suppress deformation of the mask substrate due to stress changes in the conductive film on the back surface, even when a reflective mask manufactured from a reflective mask blank using the substrate with a conductive film is exposed to an exposure environment. Also, its object is, second, to provide a substrate with a multilayer reflective film, a reflective mask blank, and a reflective mask that use the substrate with a conductive film, and third, to provide a method for manufacturing a semiconductor device that uses this reflective mask.

[0012] The present inventors have continued their intensive research to solve the conventional problems, and have completed the following configuration: (Configuration 1) A substrate with a conductive film, comprising: a substrate having a first main surface; and a conductive film formed on the first main surface and containing hydrogen, the conductive film being a single layer film, the single layer film containing a metal and nitrogen or boron, and a primary ion species being Cs ＋ When the conductive film was analyzed in an arbitrary 124 μm square area within a 5 cm square including the center of the substrate by dynamic secondary ion mass spectrometry under the conditions of a primary acceleration voltage of 3.0 kV and a primary ion current of 25 nA, the detected secondary ion intensity of hydrogen was 1.0×10 ２ A substrate with a conductive film, characterized in that the conductive film has a viscosity of cps or more. The conductive film may be a laminated film including a lower layer and an upper layer formed on the lower layer, instead of a single layer. In this case, the lower layer includes a metal and nitrogen or boron, and the upper layer includes a metal and oxygen.

[0013] (Configuration 2) The substrate with a conductive film according to Configuration 1, wherein the single layer film and the lower layer are formed in contact with the substrate, (Configuration 3) The conductive film has a secondary ion intensity of hydrogen of 1.0×10 or more within a range of 5 nm in a film thickness direction from an outermost surface of the conductive film that is farthest from the first main surface. ２ 3. The substrate with a conductive film according to configuration 1 or 2, wherein the surface roughness is cps or more.

[0014] (Structure 4) The substrate with a conductive film according to Structure 1 or 2, characterized in that it has a bottom layer containing a metal and oxygen between the substrate and the lower layer. (Structure 5) The substrate with a conductive film according to Structure 1 or 2, characterized in that the conductive film contains tantalum or chromium.

[0015] (Configuration 6) The substrate with a conductive film according to configuration 1 or 2, wherein the single layer film and the lower layer contain 10 atomic % or more and 40 atomic % or less of nitrogen.

[0016] (Configuration 7) A substrate with a multilayer reflective film, comprising a multilayer reflective film formed on a second main surface opposite to the first main surface of the substrate with a conductive film according to Configuration 1 or 2.

[0017] (Structure 8) A reflective mask blank, comprising an absorber film formed on the multilayer reflective film of the multilayer reflective film-coated substrate according to Structure 7. (Structure 9) A reflective mask, comprising an absorber film pattern obtained by patterning the absorber film of the reflective mask blank according to Structure 8.

[0018] (Configuration 10) A method for manufacturing a semiconductor device, comprising the step of transferring the absorber film pattern onto a transfer target by exposure using the reflective mask according to configuration 9.

[0019] According to the present disclosure, it is possible to provide a substrate with a conductive film that can suppress deformation of the mask substrate due to stress changes in the conductive film on the back surface, even when a reflective mask manufactured from a reflective mask blank using the substrate with a conductive film is exposed to an exposure environment. Furthermore, according to the present disclosure, it is possible to provide a multilayer reflective film-coated substrate, a reflective mask blank, and a reflective mask, all of which use the above-mentioned substrate with a conductive film. Even when a reflective mask manufactured from a reflective mask blank using the above-mentioned substrate with a conductive film is exposed to an exposure environment, it is possible to suppress deformation of the mask substrate due to stress changes in the conductive film on the back surface.

[0020] Furthermore, according to the present disclosure, a method for manufacturing a semiconductor device using this reflective mask can be provided. By using this reflective mask for pattern transfer, deformation of the mask substrate due to stress changes in the conductive film on the back surface can be suppressed even when the reflective mask is exposed to the exposure environment during pattern transfer, thereby enabling high-precision pattern transfer without misalignment during exposure.

[0021] Fig. 1 is a cross-sectional view showing a substrate with a conductive film according to an embodiment of the present disclosure; Fig. 2 is a cross-sectional view showing a substrate with a multilayer reflective film according to an embodiment of the present disclosure; Fig. 3 is a cross-sectional view showing a reflective mask blank according to an embodiment of the present disclosure; Fig. 4 is a cross-sectional view showing a reflective mask blank according to another embodiment of the present disclosure; Fig. 5 is a cross-sectional view showing a reflective mask blank according to another embodiment of the present disclosure; Fig. 6 is a cross-sectional view showing a reflective mask according to an embodiment of the present disclosure.

[0022] Embodiments of the present disclosure will be described in detail below. [Substrate with Conductive Film] First, the substrate with conductive film of the present disclosure will be described. The substrate with conductive film of the present disclosure has a substrate having a first main surface and a conductive film formed on the first main surface and containing hydrogen. The conductive film is a single layer film or a laminated film including a lower layer and an upper layer formed on the lower layer. The single layer film and the lower layer contain a metal and nitrogen or boron. When the conductive film is a laminated film, the upper layer contains a metal and oxygen. The primary ion species is Cs ＋ When the conductive film was analyzed in an arbitrary 124 μm square area within a 5 cm square including the center of the substrate by dynamic secondary ion mass spectrometry under the conditions of a primary acceleration voltage of 3.0 kV and a primary ion current of 25 nA, the detected secondary ion intensity of hydrogen was 1.0×10 ２ Here, the center of the substrate means the intersection of the diagonal lines of the first main surface.

[0023] 1 is a cross-sectional view showing a substrate with a conductive film according to one embodiment of the present disclosure. As shown in FIG. 1, a substrate with a conductive film 10 of this embodiment includes a substrate 1 having a first main surface 1a and a conductive film 2 formed on the first main surface 1a. In the illustrated state, the first main surface 1a is the back surface of the substrate 1. In this embodiment, the conductive film 2 is formed in contact with the substrate 1.

[0024] <Substrate> The substrate 1 has two main surfaces 1 a and 1 b facing each other and four end faces. When the substrate with a conductive film of the present disclosure is used, for example, in a reflective mask blank for EUV exposure, the substrate 1 is preferably a glass substrate. In particular, in order to prevent distortion of the pattern due to heat during exposure, a glass substrate having a thickness of 0±1.0×10 －７ / °C, more preferably 0±0.3×10 －７ Materials having a low thermal expansion coefficient within this range are preferably used. Examples of materials having a low thermal expansion coefficient within this range include SiO ２ -TiO ２ Glasses, multi-component glass ceramics, etc. can be used.

[0025] The main surface (second main surface) 1b of the glass substrate 1 on which the transfer pattern is formed is surface-processed to have a high degree of flatness in order to improve at least the pattern transfer accuracy and positional accuracy. In the case of EUV exposure, the flatness in a 142 mm × 142 mm area of ​​the second main surface 1b on which the transfer pattern of the glass substrate 1 is formed is preferably 0.1 μm or less, and particularly preferably 0.05 μm or less. In the present disclosure, flatness is a value representing the surface warpage (amount of deformation) indicated by TIR (Total Indicated Reading). This value is the absolute value of the difference in height between the highest point on the surface of the substrate 1 above the focal plane, which is defined by the least squares method with respect to the surface of the substrate 1 as the focal plane, and the lowest point on the surface of the substrate 1 below the focal plane.

[0026] In the case of EUV exposure, the glass substrate is, as described above, SiO ２ -TiO ２ Materials having a low thermal expansion coefficient, such as silicon-based glass, are preferably used. For the purpose of reducing the surface roughness of the glass substrate or reducing defects on the surface of the glass substrate, an underlayer may be formed on the main surface 1b of the glass substrate on which the transfer pattern is formed (second main surface) as needed. The material for such an underlayer does not need to be transparent to the exposure light, and is preferably selected from materials that provide high smoothness and good defect quality when the surface of the underlayer is precision polished. For example, silicon or silicon compounds containing silicon (e.g., SiO ２ , SiON, etc.) are preferably used as the material for the underlayer because they can achieve high smoothness when precision polished and have good defect quality. Si is particularly preferred as the material for the underlayer. By using such an underlayer, it is possible to achieve high smoothness on the surface of the glass substrate, for example, with a root-mean-square roughness (Rq) of 0.1 nm or less.

[0027] The surface of the underlayer is preferably precision-polished to have the smoothness required for a reflective mask blank substrate. The surface of the underlayer is desirably precision-polished to a root-mean-square roughness (Rq) of 0.15 nm or less, particularly preferably 0.1 nm or less. Furthermore, in consideration of the influence on the surface of the multilayer reflective film formed on the underlayer, the surface of the underlayer is desirably precision-polished so that, in relation to the maximum height (Rmax), Rmax / Rq is preferably 2 to 10, particularly preferably 2 to 8. The film thickness of the underlayer is preferably in the range of 10 nm to 300 nm, for example.

[0028] <Conductive Film> In the present disclosure, the conductive film 2 is a single-layer film or a laminated film including a lower layer and an upper layer formed on the lower layer. First, a case where the conductive film 2 is a single-layer film will be described. When the conductive film 2 is a single-layer film, the film formation process is simplified. In this case, the single-layer film is formed in contact with the substrate 1.

[0029] In the present disclosure, the monolayer film is made of a material containing a metal and nitrogen or boron. The metal preferably includes at least one selected from the group consisting of Ta, Cr, Pt, Au, Rh, Ru, Ir, and Hf. The monolayer film particularly preferably includes tantalum or chromium. That is, preferred materials for the monolayer film include tantalum-based materials and chromium-based materials. Tantalum-based materials include materials containing tantalum and nitrogen or boron, which may also contain one or more elements selected from the group consisting of carbon, oxygen, hydrogen, and noble gases. Chromium-based materials include materials containing chromium and nitrogen or boron, which may also contain one or more elements selected from the group consisting of carbon, oxygen, hydrogen, and noble gases. When the monolayer film contains a noble gas, the noble gas content is preferably 5 atomic % or less, more preferably 3 atomic % or less, and even more preferably 1.5 atomic % or less. The same applies to the lower layer, upper layer, and bottom layer described below.

[0030] In particular, since the tantalum-based material has high cleaning resistance, in the present disclosure, the monolayer film is preferably made of a tantalum-based material, and more preferably, the metal contained in the monolayer film is tantalum alone from the viewpoints of chemical resistance and wear resistance.

[0031] When the monolayer film is made of a tantalum-based material, specific examples include TaN, TaB, TaBN, etc. When the monolayer film contains tantalum, the tantalum content is preferably 50 atomic % or more, more preferably 60 atomic % or more. Furthermore, the tantalum content in the monolayer film can be 100 atomic % or less, excluding the substrate interface region and surface region described below.

[0032] When the monolayer film contains nitrogen, the nitrogen content is preferably 1 atomic % or more, more preferably 10 atomic % or more, and even more preferably 15 atomic % or more, and is preferably 40 atomic % or less, more preferably 30 atomic % or less, and even more preferably 25 atomic % or less.

[0033] When the monolayer film contains boron, the boron content is preferably 1 atomic % or more, more preferably 5 atomic % or more, and is preferably 30 atomic % or less, more preferably 20 atomic % or less, and even more preferably 18 atomic % or less.

[0034] When the monolayer film contains oxygen, the oxygen content is preferably 20 atomic % or more, more preferably 18 atomic % or more. The monolayer film may not contain oxygen except for the composition gradient region described below.

[0035] The surface of the monolayer film farthest from the first main surface 1a of the substrate 1 may be oxidized. That is, the conductive film 2 may have a very thin surface oxide layer on the surface farthest from the first main surface 1a of the substrate 1. The thickness of the surface oxide layer may be 4 nm or less, preferably 2 nm or less, and more preferably 1 nm or less. Furthermore, the interface region of the monolayer film with the substrate 1 (substrate interface region) and the surface region of the monolayer film away from the first main surface 1a of the substrate 1 are both compositionally graded regions in which the composition ratio of the monolayer film changes continuously. Therefore, the term "the conductive film 2 is a monolayer film" also includes cases in which the conductive film 2 is composed of a compositionally graded region (surface region and substrate interface region) and an internal region other than the compositionally graded region (a region in which the composition ratio is uniform in the film thickness direction). Here, "uniform composition ratio in the film thickness direction" means that the difference in the composition ratio of each constituent element in the film thickness direction is negligibly small, for example, the difference in the composition ratio of each constituent element is 3 atomic % or less. The substrate interface region is a region extending from the interface between the monolayer film and substrate 1 toward the surface (outermost surface) of the monolayer film farthest from the first main surface 1a of the substrate 1 to a thickness of, for example, more than 0 nm and not more than 5 nm. The thickness of the substrate interface region is more preferably 4 nm or less, and even more preferably 3 nm or less. The surface region is a region extending from the outermost surface of the monolayer film toward the first main surface 1a of the substrate 1 to a thickness of, for example, more than 0 nm and not more than 5 nm. The thickness of the surface region is more preferably 4 nm or less, and even more preferably 3 nm or less.

[0036] Next, a case will be described in which the conductive film 2 is a laminated film including a lower layer and an upper layer formed on the lower layer. In this case, the lower layer of the laminated film may be formed in contact with the substrate 1. The lower layer may include a compositionally graded region in which the composition changes in the thickness direction near the interface with another layer in contact with the lower layer or with the substrate 1. The thickness of this compositionally graded region may be, for example, more than 0 nm and not more than 5 nm. The same applies to the upper layer and the bottom layer described below.

[0037] The lower layer of the laminated film is made of a material containing metal and nitrogen or boron. That is, it can be made of the same material as the single layer when the conductive film 2 described above is a single layer. Therefore, a detailed description of the material of the lower layer will be omitted.

[0038] The upper layer of the laminated film is made of a material containing a metal and oxygen. The upper layer preferably contains at least one metal selected from the group consisting of Ta, Cr, Pt, Au, Rh, Ru, Ir, and Hf. The upper layer particularly preferably contains tantalum or chromium. That is, preferred materials for the upper layer include, for example, tantalum-based materials and chromium-based materials. Tantalum-based materials include materials containing tantalum and oxygen, which may also contain, for example, one or more elements selected from the group consisting of carbon, nitrogen, boron, hydrogen, and noble gases. Chromium-based materials include materials containing chromium and oxygen, which may also contain, for example, one or more elements selected from the group consisting of carbon, nitrogen, boron, hydrogen, and noble gases.

[0039] In particular, since the tantalum-based material has high cleaning resistance, in the present disclosure, it is preferable that not only the lower layer but also the upper layer of the laminated film be made of a tantalum-based material. Furthermore, from the viewpoints of chemical resistance and wear resistance, it is more preferable that the metal contained in the upper layer be tantalum alone.

[0040] When the upper layer is made of a tantalum-based material, specific examples include TaO, TaBO, TaNO, TaBNO, etc. When the upper layer contains tantalum, the tantalum content is preferably 10 atomic % or more, more preferably 20 atomic % or more. Furthermore, the tantalum content of the upper layer is preferably 70 atomic % or less, more preferably 60 atomic % or less.

[0041] The oxygen content of the upper layer is preferably 20 atomic % or more, more preferably 30 atomic % or more, and is preferably 80 atomic % or less, more preferably 70 atomic % or less.

[0042] When the upper layer contains boron, the boron content is preferably 0.5 atomic % or more and 25 atomic % or less. When the upper layer contains nitrogen, the nitrogen content is preferably 0.5 atomic % or more and 40 atomic % or less.

[0043] The composition of the upper layer may vary in the thickness direction. In this case, the average value of the content of each constituent atom in the thickness direction of the upper layer may be taken as the content of each constituent atom in the entire upper layer. The same applies to the lowermost layer described below.

[0044] Furthermore, a bottom layer made of a material containing metal and oxygen can be provided between the substrate 1 and the lower layer. That is, the conductive film 2 can be a three-layer laminate film consisting of the bottom layer, the lower layer, and the upper layer. In this case, the material of the bottom layer is preferably the same as the material of the upper layer. The bottom layer and the upper layer may be made of the same material or different materials, and if made of the same material, the composition ratios of the constituent components may be different. Furthermore, when the conductive film 2 is a laminate film, it is not limited to the two-layer or three-layer laminate film described above, but may also be a laminate film of, for example, four or more layers.

[0045] The thickness of the conductive film 2 is not particularly limited, but is preferably 10 nm or more, more preferably 20 nm or more, whether the conductive film 2 is a single-layer film or a laminated film. The thickness is preferably 500 nm or less, more preferably 200 nm or less, and even more preferably 100 nm or less. When the conductive film 2 is a laminated film, the thickness ratio of each layer is not particularly limited. The method for forming the conductive film 2 is not particularly limited, but magnetron sputtering, ion beam sputtering, or the like is usually preferred.

[0046] In the present disclosure, the conductive film 2 is preferably amorphous, which allows the surface of the conductive film 2 to be smooth and flat.

[0047] In the present disclosure, the conductive film 2 preferably has compressive stress. When the conductive film 2 has compressive stress, warpage of the substrate 1 caused by the multilayer reflective film can be reduced more effectively.

[0048] As described above, the substrate with a conductive film of the present disclosure is formed by ionizing a conductive film containing Cs as the primary ion species. ＋ When the conductive film was analyzed in an arbitrary 124 μm square area within a 5 cm square including the center of the substrate by dynamic secondary ion mass spectrometry under the conditions of a primary acceleration voltage of 3.0 kV and a primary ion current of 25 nA, the detected secondary ion intensity of hydrogen was 1.0×10 ２ It is characterized by being cps or more.

[0049] In the present disclosure, the conductive film 2 further contains hydrogen. When the conductive film 2 is analyzed by the above analytical method, the secondary ion intensity of hydrogen detected is 1.0×10 ２ By previously containing hydrogen in the range of cps or more in the conductive film 2, it is possible to prevent hydrogen generated in the exposure environment during exposure of the reflective mask from penetrating into the conductive film.

[0050] When the reflective mask is exposed to an exposure environment, it is believed that hydrogen is absorbed mainly from the outermost surface of the conductive film 2. Therefore, in the present disclosure, it is particularly desirable that the secondary ion intensity of hydrogen detected by the above analysis method is 1.0×10 or more in at least the surface region of the conductive film 2. ２ It is preferable that the substrate contains hydrogen in a range of cps or more. This makes it possible to suppress deformation of the mask substrate due to stress changes in the conductive film 2 on the back surface, even when a reflective mask manufactured from a reflective mask blank using the substrate with a conductive film of the present disclosure is exposed to an exposure environment.

[0051] Furthermore, the conductive film 2 preferably contains hydrogen not only in the surface region but also in other regions, and more preferably contains hydrogen throughout the film thickness. When the conductive film 2 is a laminated film, it is preferable that both the lower layer and the upper layer contain hydrogen. This can further suppress deformation of the mask substrate due to changes in stress in the conductive film 2.

[0052] As a method for introducing hydrogen into the conductive film 2, hydrogen can be contained in the formed conductive film 2 by including hydrogen in the sputtering gas during the formation of the conductive film 2. Alternatively, hydrogen can be contained in the formed conductive film 2 by irradiating the formed conductive film 2 with hydrogen plasma.

[0053] The secondary ion intensity of hydrogen is 1.0×10 ５ It is preferably 1.0 x 10 cps or less. ４ It is more preferable that the stress is cps or less. This allows the stress of the conductive film 2 to be adjusted to an appropriate range. The unit of secondary ion intensity, cps, stands for counts per second and means the intensity of secondary ions detected per unit time. The unit in the present disclosure is cps unless otherwise specified.

[0054] In the present disclosure, Power 300W, H ２ When hydrogen plasma irradiation is performed for five cycles under conditions of a flow rate of 100 sccm and 100 sec / cycle, the difference in flatness of the conductive film-coated substrate before and after hydrogen plasma irradiation is preferably 190 nm or less, more preferably 170 nm or less, and even more preferably 150 nm or less. The same applies to the multilayer reflective film-coated substrate, reflective mask blank, and reflective mask described below.

[0055] As described above, according to the substrate with a conductive film of the present disclosure, even if a reflective mask manufactured from a reflective mask blank using this substrate with a conductive film is exposed to an exposure environment, deformation of the mask substrate due to stress changes in the conductive film on the back surface can be suppressed.

[0056] [Substrate with Multilayer Reflective Film] Next, a multilayer reflective film-coated substrate using the conductive film-coated substrate of the present disclosure will be described. Fig. 2 is a cross-sectional view showing a multilayer reflective film-coated substrate according to one embodiment of the present disclosure. As shown in Fig. 2, a multilayer reflective film-coated substrate 20 according to one embodiment has a multilayer reflective film 3 formed on a second main surface 1b (the surface of the substrate 1 in the illustrated state) opposite to the first main surface 1a of the conductive film-coated substrate 10, which reflects EUV light, which is exposure light.

[0057] The multilayer reflective film coated substrate 20 of this embodiment is produced by forming a multilayer reflective film 3 that reflects exposure light, for example, EUV light, on the second main surface 1 b of the conductive film coated substrate 10 .

[0058] The multilayer reflective film 3 is a multilayer film in which low-refractive index layers and high-refractive index layers are alternately stacked. The multilayer reflective film 3 is generally a multilayer film in which thin films of heavy elements or their compounds and thin films of light elements or their compounds are alternately stacked in approximately 30 to 60 periods. For example, a Mo / Si periodic stacked film in which Mo films and Si films are alternately stacked in approximately 40 periods is preferably used as a multilayer reflective film for EUV light with a wavelength of 13 to 14 nm. Other multilayer reflective films used in the EUV light range include Ru / Si periodic multilayer films, Mo / Be periodic multilayer films, Mo compound / Si compound periodic multilayer films, Si / Nb periodic multilayer films, Si / Mo / Ru periodic multilayer films, Si / Mo / Ru / Mo periodic multilayer films, and Si / Ru / Mo / Ru periodic multilayer films. The materials may be appropriately selected depending on the exposure wavelength.

[0059] Typically, a protective film 4 is preferably provided on the multilayer reflective film 3 to protect the multilayer reflective film during patterning or pattern modification of the absorber film, as described below (see FIG. 4 ). The protective film 4 is sometimes called a capping layer. Such a protective film 4 is formed, for example, from a material containing ruthenium as a primary component. Examples of materials containing ruthenium as a primary component include Ru metal alone, Ru alloys containing Ru with at least one metal selected from titanium (Ti), niobium (Nb), rhodium (Rh), molybdenum (Mo), zirconium (Zr), yttrium (Y), boron (B), lanthanum (La), cobalt (Co), chromium (Cr), and rhenium (Re), and materials containing nitrogen. Incidentally, "containing substance A as a primary component" refers to the inclusion of 50 atomic % or more of substance A. The thickness of the protective film 4 is preferably, for example, 1 nm or more. The thickness of the protective film 4 is preferably 5 nm or less.

[0060] The method for forming the multilayer reflective film 3 and the protective film 4 is not particularly limited, but ion beam sputtering or magnetron sputtering is usually preferred.

[0061] [Reflective Mask Blank] Next, a reflective mask blank according to the present disclosure will be described. The reflective mask blank according to the present disclosure comprises a substrate having a first main surface and a second main surface opposite the first main surface, a conductive film formed on the first main surface and containing hydrogen, a reflective multilayer film formed on the second main surface, and an absorber film formed on the reflective multilayer film. The conductive film is a single layer film or a laminated film including a lower layer and an upper layer formed on the lower layer. The single layer film and the lower layer contain a metal and nitrogen or boron. When the conductive film is a laminated film, the upper layer contains a metal and oxygen. The primary ion species is Cs ＋ When the conductive film was analyzed in an arbitrary 124 μm square area within a 5 cm square including the center of the substrate by dynamic secondary ion mass spectrometry under the conditions of a primary acceleration voltage of 3.0 kV and a primary ion current of 25 nA, the detected secondary ion intensity of hydrogen was 1.0×10 ２ cps or more.

[0062] The arbitrary 124 μm square region can be, for example, a region including the center of the conductive film when viewed from above. When the surface of the conductive film is rectangular, the center of the conductive film is the intersection of the diagonals of the rectangle. Furthermore, the center of the arbitrary 124 μm square region is the intersection of the diagonals, and preferably coincides with the center of the conductive film when viewed from above. Furthermore, it is more preferable that the center of the arbitrary 124 μm square region coincides with the center of the first main surface (rear surface) of the substrate. The center of the first main surface of the substrate is the intersection of the diagonals of the first main surface.

[0063] Fig. 3 is a cross-sectional view showing a reflective mask blank according to an embodiment of the present disclosure. As shown in Fig. 3, in a reflective mask blank 30 according to an embodiment of the present disclosure, an absorber film 5 is formed on the multilayer reflective film 3 of the multilayer reflective film-coated substrate 20. In addition, the conductive film 2 is formed on the first main surface 1a of the substrate 1.

[0064] The reflective mask blank 30 is produced by forming an absorber film 5 that absorbs EUV light on the multilayer reflective film 3 (or the protective film 4, if any, on the surface of the multilayer reflective film 3) in the multilayer reflective film-coated substrate 20.

[0065] The absorber film 5 has a function of absorbing exposure light, such as EUV light, and may have a desired reflectance difference between light reflected by the multilayer reflective film 3 or the protective film 4 on the multilayer reflective film 3 and light reflected by the absorber film pattern 5a (see FIG. 6) in a reflective mask 60 (see FIG. 6) fabricated using the reflective mask blank. For example, the reflectance difference of the absorber film 5 for EUV light is selected between 0.1% or more and 40% or less. In addition to the reflectance difference, the absorber film 5 may have a desired phase difference between light reflected by the multilayer reflective film 3 or the protective film 4 and light reflected by the absorber film pattern 5a. When a desired phase difference is present between light reflected by the multilayer reflective film 3 or the protective film 4 and light reflected by the absorber film pattern 5a, the absorber film 5 in the reflective mask blank may be referred to as a phase shift film. When improving contrast by providing a desired phase difference between the light reflected by the multilayer reflective film 3 or the protective film 4 and the light reflected by the absorber film pattern 5a, it is preferable to set the phase difference in the range of 150 degrees to 310 degrees, and it is preferable to set the reflectance difference of the absorber film 5 to 3% or more and 40% or less.

[0066] The absorber film 5 may have a single layer or a laminated structure. In the case of a laminated structure, it may be a laminated film of the same material or a laminated film of different materials. The laminated film may have a material or composition that changes stepwise and / or continuously in the film thickness direction. When the absorber film 5 is a laminated film, the absorber film 5 may include, for example, a layer (buffer layer) having etching selectivity with respect to the protective film at a position closest to the substrate in the film thickness direction.

[0067] The material of the absorber film 5 is not particularly limited as long as it has the function of absorbing EUV light, can be processed by etching or the like, and has a high etching selectivity with respect to the multilayer reflective film 3 or the protective film 4. The material of the absorber film 5 is preferably etchable by dry etching using a chlorine (Cl)-based gas and / or a fluorine (F)-based gas. As a material having the above-mentioned functions, at least one metal selected from palladium (Pd), silver (Ag), platinum (Pt), gold (Au), iridium (Ir), tungsten (W), chromium (Cr), cobalt (Co), manganese (Mn), tin (Sn), tantalum (Ta), vanadium (V), nickel (Ni), hafnium (Hf), iron (Fe), copper (Cu), tellurium (Te), zinc (Zn), magnesium (Mg), germanium (Ge), aluminum (Al), rhodium (Rh), ruthenium (Ru), molybdenum (Mo), niobium (Nb), titanium (Ti), zirconium (Zr), yttrium (Y), and silicon (Si), an alloy containing two or more metals, or a compound thereof can be preferably used. The compound may contain oxygen (O), nitrogen (N), carbon (C), hydrogen (H), and / or boron (B) in addition to the above metal or alloy.

[0068] The thickness of the absorber film 5 is preferably within a range of, for example, about 30 nm to 100 nm. There are no particular restrictions on the method for forming the absorber film 5, but magnetron sputtering, ion beam sputtering, or the like are usually suitable.

[0069] The details of the configuration of the conductive film 2 in the reflective mask blank 30 are as explained above in the description of the substrate with a conductive film.

[0070] In the reflective mask blank 30 , the single layer film and the lower layer are preferably formed in contact with the substrate 1 .

[0071] In the reflective mask blank 30, the conductive film 2 has a secondary ion intensity of hydrogen of at least 1.0×10 within a range of 5 nm in the film thickness direction from the outermost surface of the conductive film that is the farthest from the first main surface 1 a of the substrate 1. ２It is preferable that the viscosity is cps or more.

[0072] Furthermore, the reflective mask blank 30 may have a lowermost layer containing metal and oxygen between the substrate 1 and the lower layer.

[0073] In the reflective mask blank 30, the conductive film 2 preferably contains tantalum or chromium.

[0074] In the reflective mask blank 30, the single layer film and the lower layer preferably contain nitrogen in an amount of 10 atomic % or more and 40 atomic % or less.

[0075] 4 is a cross-sectional view showing a reflective mask blank according to another embodiment of the present disclosure. As shown in Fig. 4, a reflective mask blank 40 of this embodiment has the above-mentioned protective film 4 on the surface of the multilayer reflective film 3. That is, the protective film 4 is formed between the multilayer reflective film 3 and the absorber film 5. The protective film 4 is as described above.

[0076] 5 is a cross-sectional view showing a reflective mask blank according to another embodiment of the present disclosure. As shown in Fig. 5, in the reflective mask blank 50 of this embodiment, an etching mask film 6 is formed on the absorber film 5.

[0077] The etching mask film 6 functions as a mask when patterning the absorber film 5 and is made of a material with different etching selectivity from the material of the top layer of the absorber film 5. For example, when the absorber film 5 is made of Ta alone or a material containing Ta, the etching mask film 6 can be made of a material such as chromium, a chromium compound, or silicon, a silicon compound. Examples of chromium compounds include materials containing Cr and at least one element selected from N, O, C, and H. Examples of silicon compounds include materials containing Si and at least one element selected from N, O, C, and H, as well as metal silicon (metal silicide) and metal silicon compounds (metal silicide compounds) containing metal in silicon or a silicon compound. Examples of metal silicon compounds include materials containing metal, Si, and at least one element selected from N, O, C, and H. Furthermore, when the absorber film 5 is a laminated film in which a material containing Ta and a material containing Cr are formed in this order on the protective film 4, the material of the etching mask film 6 can be selected from silicon, silicon compounds, metal silicides, metal silicide compounds, etc., which have etching selectivity different from that of the material containing Cr.

[0078] Furthermore, the reflective mask blank 50 according to this embodiment (the same applies to the above-mentioned reflective mask blanks 30 and 40) can also be configured such that the absorber film 5 is composed of a laminated film of a top layer and other layers made of materials with different etching selectivities, with the top layer functioning as an etching mask film for the other layers.

[0079] As described above, the absorber film 5 in the reflective mask blanks 30, 40, and 50 according to the above-described embodiments is not limited to a single-layer film, but can be configured as a laminated film of the same material or a laminated film of different materials, and further can be configured as a laminated film of the absorber film 5 of the above-described laminated film or single-layer film and a film that functions as an etching mask film.

[0080] The reflective mask blanks 30, 40, and 50 according to the above-described embodiments also include an embodiment in which a resist film is formed on the absorber film 5 or the etching mask film 6. Such a resist film is used when the absorber film 5 in the reflective mask blank is patterned by lithography.

[0081] According to the reflective mask blanks 30, 40, and 50 of the above-described embodiments, even if a reflective mask manufactured from the reflective mask blank is exposed to an exposure environment, deformation of the mask substrate due to stress changes in the conductive film on the back surface can be suppressed.

[0082] [Reflective Mask] The present disclosure also provides a reflective mask fabricated using the above-described reflective mask blank 30 or the like. Fig. 6 is a cross-sectional view showing a reflective mask according to one embodiment of the present disclosure. As shown in Fig. 6, the reflective mask 60 of this embodiment has an absorber film pattern 5a obtained by patterning the absorber film 5 of the above-described reflective mask blank 40 by etching, for example.

[0083] The most suitable method for patterning the absorber film 5, which will become the transfer pattern in the reflective mask blank 40, is EUV lithography. That is, a resist film is formed by baking an electron beam lithography resist applied to the reflective mask blank 40. The resist film is written and developed using an electron beam lithography device, and a resist pattern corresponding to the transfer pattern is formed on the resist film. Thereafter, the absorber film 5 is patterned using this resist pattern as a mask to form an absorber film pattern 5a. In this manner, the reflective mask 60 shown in FIG. 6 is produced.

[0084] The protective film 4 in the region exposed by forming the absorber film pattern 5a may be eventually removed, but may not be particularly removed if it remains and does not affect its function as a reflective mask. Furthermore, when a reflective mask is manufactured using a reflective mask blank 50 having a configuration including the above-mentioned etching mask film 6, the etching mask film 6 may be eventually removed, but may not be particularly removed if it remains and does not affect its function as a reflective mask.

[0085] [Method for Manufacturing a Semiconductor Device] The present disclosure also provides a method for manufacturing a semiconductor device. By using the reflective mask 60 of the present disclosure to transfer the transfer pattern (absorber film pattern 5a) to a transfer target, such as a resist film on a semiconductor substrate, a high-quality semiconductor device with few defects can be manufactured. By performing pattern transfer using a reflective mask 60 manufactured from a reflective mask blank using a substrate with a conductive film of the present disclosure, deformation of the mask substrate due to stress changes in the conductive film 2 on the back surface can be suppressed even when the reflective mask 60 is exposed to the exposure environment during pattern transfer. This allows for high-precision pattern transfer without misalignment during exposure.

[0086] As explained in detail above, according to the present disclosure, it is possible to provide a substrate with a conductive film that can suppress deformation of the mask substrate due to stress changes in the conductive film on the back surface, even when a reflective mask manufactured from a reflective mask blank using the substrate with a conductive film is exposed to an exposure environment. Furthermore, according to the present disclosure, it is possible to provide a multilayer reflective film-coated substrate, a reflective mask blank, and a reflective mask, all of which use the above substrate with a conductive film. Even when a reflective mask manufactured from a reflective mask blank using the above substrate with a conductive film is exposed to an exposure environment, it is possible to suppress deformation of the mask substrate due to stress changes in the conductive film on the back surface.

[0087] Furthermore, according to the present disclosure, by performing pattern transfer using this reflective mask, deformation of the mask substrate due to changes in stress in the conductive film on the back surface can be suppressed even when the reflective mask is exposed to the exposure environment during pattern transfer. Therefore, high-precision pattern transfer can be performed without causing transfer position misalignment during exposure. As a result, high-quality semiconductor devices with few defects can be manufactured.

[0088] Hereinafter, the embodiments of the present disclosure will be described in more detail with reference to examples. ２ -TiO ２A glass substrate (a 6-inch square substrate with dimensions of approximately 152.0 mm x 152.0 mm and a thickness of approximately 6.35 mm) was prepared. This glass substrate 1 was mechanically polished to have a smooth surface with a root-mean-square roughness (Rq) of 0.25 nm and a flatness of 100 nm or less. The surface roughness was measured with an atomic force microscope (AFM) over a measurement area of ​​1 μm x 1 μm.

[0089] First, a conductive film 2 made of TaNH was formed on the rear surface (first main surface) 1a of the substrate 1. The substrate 1 was placed in a sputtering device, and a tantalum (Ta) target was used, and argon (Ar), nitrogen (N ２ ) and hydrogen (H ２ ) mixed gas (flow ratio (%) Ar:N ２ : H ２ A TaNH film having a thickness of 70 nm was formed by reactive sputtering using a sputtering gas mixture of 1000 vol% of ZnO, 1000 vol% of ZnO, 1000 vol% of ZnO, and 1000 vol% of ZnO. The nitrogen content of the TaNH film was 35 atomic %.

[0090] The TaNH conductive film 2 thus formed is ion-doped with Cs ＋ The conductive film 2 was analyzed in an arbitrary 124 μm square area within a 5 cm square including the center of the substrate 1 by dynamic secondary ion mass spectrometry under the conditions of a primary acceleration voltage of 3.0 kV and a primary ion current of 25 nA. As a result, the secondary ion intensity of hydrogen detected was 1.0×10 ２ Dynamic secondary ion mass spectrometry was performed using a PHI ADEPT1010 (manufactured by ULVAC-PHI) in negative ion detection mode.

[0091] Next, on the substrate surface (second main surface) 1b opposite to the conductive film 2 of another substrate with a conductive film produced in the same manner as above, an ion beam sputtering apparatus was used to stack 40 periods of Si films (thickness: 4.2 nm) and Mo films (thickness: 2.8 nm), with one period being one period, and finally a Si film (thickness: 4 nm), thereby forming a multilayer reflective film 3. Furthermore, a protective film 4 made of Ru (thickness: 2.5 nm) was formed on the multilayer reflective film 3. In this manner, a substrate with a multilayer reflective film was obtained.

[0092] Subsequently, an absorber film 5 consisting of a laminated film of a TaBN film (film thickness: 56 nm) and a TaBO film (film thickness: 14 nm) was formed on the protective film 4 of the multilayer reflective film-coated substrate using a DC magnetron sputtering apparatus. In this manner, a reflective mask blank 40 was obtained.

[0093] The substrate flatness of the reflective mask blank 40 thus obtained was measured. The measurement of the substrate flatness was carried out in the same manner as in the case of the glass substrate. Next, in order to simulate the exposure environment of a reflective mask, the reflective mask blank 40 was exposed to a 300W power, H ２ Hydrogen plasma irradiation was performed for five cycles under conditions of a flow rate of 100 sccm and 100 sec / cycle. The substrate flatness of the reflective mask blank 40 after hydrogen plasma irradiation was measured in the same manner as above. As a result, the difference in substrate flatness of the reflective mask blank 40 before and after hydrogen plasma irradiation was 100 nm.

[0094] Next, a reflective mask was fabricated using another reflective mask blank fabricated in the same manner as above. First, an electron beam lithography resist was applied to the reflective mask blank and baked to form a resist film. A predetermined mask pattern was written onto this resist film using an electron beam and developed to form a resist pattern.

[0095] Using this resist pattern as a mask, a fluorine-based gas (CF ４ The TaBO film was then heated with a chlorine-based gas (Cl ２ The TaBN film was etched away using a gas. As a result, an absorber film pattern 5a was formed on the protective film 4. Furthermore, the resist pattern remaining on the absorber film pattern was removed, and a reflective mask 60 was obtained.

[0096] The reflective mask 60 of this embodiment obtained in this way was set in an exposure apparatus, and a pattern was transferred onto a semiconductor substrate on which a resist film had been formed. As a result, high-precision pattern transfer was achieved without any transfer position deviation during exposure.

[0097] Example 2 A conductive film 2 made of TaH was formed on the rear surface 1a of a substrate 1 prepared in the same manner as in Example 1. The substrate 1 was placed in a sputtering device, and a tantalum (Ta) target was used, and xenon (Xe) and hydrogen (H ２ ) mixed gas (flow ratio (%) Xe:H ２ A TaH film having a thickness of 70 nm was formed by reactive sputtering using a mixture of 1000 vol% HCl and 1000 vol% HCl (80:20) as a sputtering gas. The TaH conductive film 2 was analyzed in the same manner as in Example 1. The secondary ion intensity of hydrogen detected was 1.0×10 ３ It was cps.

[0098] Next, on the substrate surface 1b opposite to the conductive film 2 of another substrate with a conductive film prepared in the same manner as above, a multilayer reflective film 3, a protective film 4 and an absorber film 5 were formed in that order in the same manner as in Example 1, thereby obtaining a reflective mask blank 40 of Example 2.

[0099] The difference in substrate flatness of the obtained reflective mask blank 40 before and after hydrogen plasma irradiation was checked in the same manner as in Example 1, and was found to be 80 nm. Next, a reflective mask 60 of Example 2 was produced in the same manner as in Example 1, using another reflective mask blank produced in the same manner as above.

[0100] The reflective mask 60 of Example 2 thus obtained was set in an exposure apparatus, and a pattern was transferred onto a semiconductor substrate on which a resist film had been formed. As a result, high-precision pattern transfer was achieved without any transfer position deviation during exposure.

[0101] Example 3 A conductive film 2 consisting of a TaNH film as a lower layer and a TaOH film as an upper layer was formed on the rear surface 1a of a substrate 1 prepared in the same manner as in Example 1. The substrate 1 was placed in a sputtering device, and a tantalum (Ta) target was used, and xenon (Xe), nitrogen (N ２ ) and hydrogen (H ２ ) mixed gas (flow ratio (%) Xe:N ２ : H ２A TaNH film with a thickness of 60 nm was formed by reactive sputtering using a mixture of tantalum (Ta) and xenon (Xe) and oxygen (O ２ ) and hydrogen (H ２ ) mixed gas (flow ratio (%) Xe:O ２ : H ２ A TaOH film having a thickness of 10 nm was formed using a sputtering gas of 44:37:19. The oxygen content of the TaOH film was 50 atomic %.

[0102] As a result of analyzing the conductive film 2 composed of the TaNH film and the TaOH film in the same manner as in Example 1, the secondary ion intensity of hydrogen detected in the TaNH film was 1.0×10 ２ The secondary ion intensity of hydrogen detected for the TaOH film was 1.0×10 ３ It was cps.

[0103] Next, on the substrate surface 1b opposite to the conductive film 2 of another substrate with a conductive film prepared in the same manner as above, a multilayer reflective film 3, a protective film 4 and an absorber film 5 were formed in that order in the same manner as in Example 1, thereby obtaining a reflective mask blank 40 of Example 3.

[0104] The difference in substrate flatness of the obtained reflective mask blank 40 before and after hydrogen plasma irradiation was checked in the same manner as in Example 1, and was found to be 50 nm. Next, a reflective mask 60 of Example 3 was produced in the same manner as in Example 1, using another reflective mask blank 40 produced in the same manner as above.

[0105] The reflective mask 60 of Example 3 thus obtained was set in an exposure apparatus, and a pattern was transferred onto a semiconductor substrate on which a resist film had been formed. As a result, high-precision pattern transfer was achieved without any transfer position deviation during exposure.

[0106] Example 4 A conductive film 2 consisting of a TaBH film as a lower layer and a TaBOH film as an upper layer was formed on the rear surface 1a of a substrate 1 prepared in the same manner as in Example 1. The substrate 1 was placed in a sputtering device, and a TaB target was used, and xenon (Xe) and hydrogen (H ２ ) mixed gas (flow ratio (%) Xe:H ２ A TaBH film with a thickness of 60 nm was formed by reactive sputtering using a mixture of argon (Ar) and oxygen (O) in a ratio of 80:20 as the sputtering gas. The boron content of the TaBH film was 16 atomic %. Subsequently, a TaB target was also used, and a mixture of argon (Ar) and oxygen (O) was also used. ２ ) and hydrogen (H ２ ) mixed gas (flow ratio (%) Ar:O ２ : H ２ A TaBOH film having a thickness of 10 nm was formed using a sputtering gas of 10 atomic % boron and 50 atomic % oxygen.

[0107] As a result of analyzing the conductive film 2 composed of the TaBH film and the TaBOH film in the same manner as in Example 1, the secondary ion intensity of hydrogen detected in the TaBH film was 1.0×10 ２ The secondary ion intensity of hydrogen detected for the TaBOH film was 1.0 × 10 ２ It was cps.

[0108] Next, on the substrate surface 1b opposite to the conductive film 2 of another substrate with a conductive film prepared in the same manner as above, a multilayer reflective film 3, a protective film 4 and an absorber film 5 were formed in that order in the same manner as in Example 1, thereby obtaining a reflective mask blank 40 of Example 4.

[0109] The difference in substrate flatness of the obtained reflective mask blank 40 before and after hydrogen plasma irradiation was checked in the same manner as in Example 1, and was found to be 25 nm. Next, a reflective mask 60 of Example 4 was produced in the same manner as in Example 1, using another reflective mask blank 40 produced in the same manner as above.

[0110] The reflective mask 60 of Example 4 thus obtained was set in an exposure apparatus, and a pattern was transferred onto a semiconductor substrate on which a resist film had been formed. As a result, high-precision pattern transfer was achieved without any transfer position deviation during exposure.

[0111] Example 5 A conductive film 2 made of CrONH was formed on the rear surface 1a of a substrate 1 prepared in the same manner as in Example 1. The substrate 1 was placed in a sputtering device, and a chromium (Cr) target was used, and a gas containing argon (Ar) and oxygen (O ２ ), nitrogen (N ２ ) and hydrogen (H ２ ) mixed gas (flow ratio (%) Ar:O ２ :N ２ : H ２ A 70 nm thick CrONH film was formed by reactive sputtering using a sputtering gas of 0.1% oxygen, 0.1% nitrogen, and 0.1% oxygen. The CrONH conductive film 2 was analyzed in the same manner as in Example 1, and the detected secondary ion intensity of hydrogen was 1.0×10 ２ It was cps.

[0112] Next, on the substrate surface 1b opposite to the conductive film 2 of another substrate with a conductive film prepared in the same manner as above, a multilayer reflective film 3, a protective film 4 and an absorber film 5 were formed in that order in the same manner as in Example 1, thereby obtaining a reflective mask blank 40 of Example 5.

[0113] The difference in substrate flatness of the obtained reflective mask blank 40 before and after hydrogen plasma irradiation was checked in the same manner as in Example 1, and was found to be 100 nm. Next, a reflective mask 60 of Example 5 was produced in the same manner as in Example 1, using another reflective mask blank 40 produced in the same manner as above.

[0114] The reflective mask 60 of Example 5 thus obtained was set in an exposure apparatus, and a pattern was transferred onto a semiconductor substrate on which a resist film had been formed. As a result, high-precision pattern transfer was achieved without any transfer position deviation during exposure.

[0115] Comparative Example 1 A conductive film made of TaN was formed on the back surface of a substrate prepared in the same manner as in Example 1. The substrate was placed in a sputtering device, and a tantalum (Ta) target was used, and xenon (Xe) and nitrogen (N ２ ) mixed gas (flow ratio (%) Xe:N ２ A TaN film (composition ratio Ta:N=65 atomic %:35 atomic %) having a thickness of 70 nm was formed by reactive sputtering using a sputtering gas of Ta:N=37.5:62.5. The TaN conductive film was analyzed in the same manner as in Example 1, and the detected secondary ion intensity of hydrogen was 1.0×10 １ It was cps.

[0116] Next, on the surface of another substrate with a conductive film prepared in the same manner as above, opposite the conductive film, a multilayer reflective film, a protective film, and an absorber film were formed in that order in the same manner as in Example 1, thereby obtaining a reflective mask blank of Comparative Example 1.

[0117] The difference in substrate flatness of the obtained reflective mask blank before and after hydrogen plasma irradiation was checked in the same manner as in Example 1, and the result was 200 nm, indicating significant deformation of the mask blank substrate. Next, a reflective mask of Comparative Example 1 was produced in the same manner as in Example 1 using another reflective mask blank produced in the same manner as above.

[0118] The reflective mask of Comparative Example 1 thus obtained was set in an exposure apparatus, and a pattern was transferred onto a semiconductor substrate on which a resist film had been formed. As a result, a transfer position shift occurred during exposure, and high-precision pattern transfer was not possible. This is thought to be because the mask substrate was deformed due to stress changes in the conductive film caused by hydrogen penetration into the conductive film of the reflective mask, resulting in a transfer position shift during exposure.

[0119] Comparative Example 2 A conductive film made of CrN was formed on the back surface of a substrate prepared in the same manner as in Example 1. The substrate was placed in a sputtering device, and a chromium (Cr) target was used, and argon (Ar) and nitrogen (N ２ ) mixed gas (flow ratio (%) Ar:N ２A 70 nm thick CrN film (composition ratio Cr:N=75 atomic %:25 atomic %) was formed by reactive sputtering using a sputtering gas of Cr:N=60:40. The CrN conductive film was analyzed in the same manner as in Example 1, and the detected secondary ion intensity of hydrogen was 1.0×10 １ It was cps.

[0120] Next, on the surface of another substrate with a conductive film prepared in the same manner as above, opposite the conductive film, a multilayer reflective film, a protective film, and an absorber film were formed in that order in the same manner as in Example 1, thereby obtaining a reflective mask blank of Comparative Example 2.

[0121] The difference in substrate flatness of the obtained reflective mask blank before and after hydrogen plasma irradiation was checked in the same manner as in Example 1, and the result was 200 nm, indicating significant deformation of the mask blank substrate. Next, a reflective mask of Comparative Example 2 was produced in the same manner as in Example 1, using another reflective mask blank produced in the same manner as above.

[0122] The reflective mask of Comparative Example 2 thus obtained was set in an exposure apparatus, and a pattern was transferred onto a semiconductor substrate on which a resist film had been formed. As a result, a transfer position shift occurred during exposure, and high-precision pattern transfer was not possible. This is thought to be because the mask substrate was deformed due to stress changes in the conductive film caused by hydrogen penetration into the conductive film of the reflective mask, resulting in a transfer position shift during exposure.

[0123] As is clear from the examples described above, the substrate with a conductive film of the present disclosure can suppress deformation of the mask substrate due to stress changes in the conductive film on the back surface, even when a reflective mask manufactured from a reflective mask blank using this substrate with a conductive film is exposed to an exposure environment. Therefore, by performing pattern transfer using this reflective mask, even when the reflective mask is exposed to the exposure environment during pattern transfer, deformation of the mask substrate due to stress changes in the conductive film on the back surface can be suppressed, thereby enabling high-precision pattern transfer without causing transfer position deviation during exposure.

[0124] REFERENCE SIGNS LIST 1 substrate 1a first main surface 1b second main surface 2 conductive film 3 multilayer reflective film 4 protective film 5 absorber film 6 etching mask film 10 substrate with conductive film 20 substrate with multilayer reflective film 30, 40, 50 reflective mask blank 60 reflective mask

Claims

1. A substrate with a conductive film, comprising: a substrate having a first main surface; and a conductive film formed on the first main surface and containing hydrogen, the conductive film being a single layer film, the single layer film containing a metal and nitrogen or boron, and a primary ion species being Cs ＋ When the conductive film was analyzed in an arbitrary 124 μm square region within a 5 cm square including the center of the substrate by dynamic secondary ion mass spectrometry under the conditions of a primary acceleration voltage of 3.0 kV and a primary ion current of 25 nA, the secondary ion intensity of detected hydrogen was 1.0×10 ２ A substrate with a conductive film, characterized in that the conductive film has a surface area of ​​100 cps or more.

2. The substrate with a conductive film according to claim 1, wherein the monolayer film is formed in contact with the substrate.

3. A substrate with a conductive film, comprising: a substrate having a first main surface; and a conductive film formed on the first main surface and containing hydrogen, the conductive film being a laminated film including a lower layer and an upper layer formed on the lower layer, the lower layer containing a metal and nitrogen or boron, the upper layer containing a metal and oxygen, and a primary ion species being Cs ＋ When the conductive film was analyzed in an arbitrary 124 μm square region within a 5 cm square including the center of the substrate by dynamic secondary ion mass spectrometry under the conditions of a primary acceleration voltage of 3.0 kV and a primary ion current of 25 nA, the secondary ion intensity of detected hydrogen was 1.0×10 ２ A substrate with a conductive film, characterized in that the conductive film has a surface area of ​​100 cps or more.

4. The substrate with a conductive film according to claim 3, wherein the lower layer is formed in contact with the substrate.

5. The conductive film has a secondary ion intensity of hydrogen of 1.0×10 or more within a range of 5 nm in a film thickness direction from an outermost surface of the conductive film that is farthest from the first main surface. ２ 4. The substrate with a conductive film according to claim 1, wherein the conductive film has a viscosity of cps or more.

6. The substrate with a conductive film according to claim 3 or 4, further comprising a bottom layer containing metal and oxygen between the substrate and the lower layer.

7. The substrate with a conductive film according to claim 1 or 3, characterized in that the conductive film contains tantalum or chromium.

8. The substrate with a conductive film according to claim 1 or 2, wherein the single layer film contains 10 atomic % or more and 40 atomic % or less of nitrogen.

9. The substrate with a conductive film according to claim 3 or 4, wherein the lower layer contains 10 atomic % or more and 40 atomic % or less of nitrogen.

10. A substrate with a multilayer reflective film, comprising: a multilayer reflective film formed on a second main surface opposite to the first main surface of the substrate with a conductive film according to claim 1 or 3.

11. A reflective mask blank, comprising an absorber film formed on the multilayer reflective film of the multilayer reflective film-coated substrate according to claim 10.

12. A reflective mask, comprising an absorber film pattern obtained by patterning the absorber film of the reflective mask blank according to claim 11.

13. A method for manufacturing a semiconductor device, comprising the step of transferring the absorber film pattern to a transfer target by exposure using the reflective mask according to claim 12.

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