WO2015145887A1 - マスクブランク用基板、マスクブランク及び転写用マスク、並びにそれらの製造方法 - Google Patents
マスクブランク用基板、マスクブランク及び転写用マスク、並びにそれらの製造方法 Download PDFInfo
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- WO2015145887A1 WO2015145887A1 PCT/JP2014/082481 JP2014082481W WO2015145887A1 WO 2015145887 A1 WO2015145887 A1 WO 2015145887A1 JP 2014082481 W JP2014082481 W JP 2014082481W WO 2015145887 A1 WO2015145887 A1 WO 2015145887A1
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- mask blank
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- blank substrate
- main surface
- mask
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/30—Measuring arrangements characterised by the use of optical techniques for measuring roughness or irregularity of surfaces
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N21/956—Inspecting patterns on the surface of objects
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
- G03F1/60—Substrates
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
- G03F1/68—Preparation processes not covered by groups G03F1/20 - G03F1/50
- G03F1/82—Auxiliary processes, e.g. cleaning or inspecting
- G03F1/84—Inspecting
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N21/956—Inspecting patterns on the surface of objects
- G01N2021/95676—Masks, reticles, shadow masks
Definitions
- the present invention can suppress the detection of pseudo defects due to the surface roughness of a substrate in a defect inspection using a high-sensitivity defect inspection apparatus, and can easily find a fatal defect such as a foreign object or a scratch.
- the present invention relates to a mask blank substrate, a mask blank obtained from the mask blank substrate, a transfer mask, and a method for manufacturing the mask blank substrate, the mask blank, and the transfer mask.
- a fine pattern is formed using a photolithography method.
- a number of transfer masks usually called photomasks, are used to form this fine pattern.
- This transfer mask is generally provided with a fine pattern made of a metal thin film or the like on the main surface of a translucent glass substrate, and the photolithographic method is also used in the manufacture of this transfer mask.
- a mask blank having a thin film (for example, a light shielding film) for forming a transfer pattern (mask pattern) on a light-transmitting substrate such as a glass substrate is used.
- the production of a transfer mask using the mask blank includes a drawing process for drawing a desired pattern on the resist film formed on the mask blank, and developing the resist film after drawing to form a desired resist pattern.
- the developing process is formed, the etching process is performed to etch the thin film using the resist pattern as a mask, and the process is performed to peel and remove the remaining resist pattern.
- a desired pattern is drawn on the resist film formed on the mask blank, and then a developing solution is supplied to dissolve a portion of the resist film that is soluble in the developing solution, thereby forming a resist pattern.
- the resist pattern is used as a mask to remove the exposed portion of the thin film on which the resist pattern is not formed by dry etching or wet etching, thereby forming a desired mask pattern on the translucent substrate. Form. In this way, a transfer mask can be manufactured.
- phase shift mask As a type of transfer mask, in addition to a binary mask having a light shielding film pattern made of a chromium-based material on a conventional translucent substrate, a phase shift mask (also simply referred to as a phase shift mask) is used.
- This phase shift mask has a structure having a phase shift film on a translucent substrate. This phase shift film causes a predetermined phase difference with respect to the exposure light.
- a material containing a molybdenum silicide compound is used.
- binary masks using a material containing a metal silicide compound such as molybdenum as a light-shielding film have been used.
- these binary masks and phase shift masks are collectively referred to as transmission masks.
- the binary mask blank and the phase shift mask blank which are the original plates used for the transmission mask are collectively referred to as a transmission mask blank.
- a substrate with higher smoothness is required from the viewpoint of improvement in defect quality accompanying the recent miniaturization of patterns and optical characteristics required for a transfer mask.
- Patent Document 1 As a general precision polishing glass manufacturing method, for example, in Japanese Patent Application Laid-Open No. 64-40267 (Patent Document 1), a glass surface is polished with an abrasive mainly composed of cerium oxide, and then colloidal silica is used. A method for producing precision-polished glass, characterized in that it is finish-polished using a glass, is described.
- a mask blank serving as an original of a transfer mask used in photolithography is manufactured by forming a thin film for pattern formation on a substrate such as synthetic quartz glass by a sputtering method.
- Substrates used for mask blanks are required to have no defects on the main surface or to have a predetermined number or less even if defects exist. For this reason, the main surface of the substrate is subjected to defect inspection using a defect inspection apparatus as disclosed in Japanese Patent Application Laid-Open No. 2001-027611 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2002-328099 (Patent Document 3). It is usually performed to inspect for the presence or absence of defects on the main surface.
- two inspection methods are mainly used.
- One of the inspection methods is to irradiate the main surface of the substrate with two polarized beams having interference with each other as disclosed in Patent Document 2, and to detect the presence or absence of defects and the defects from interference with reflected light.
- Another inspection method is an optical system in which a spatial filter such as a knife edge is incorporated in a confocal optical system as disclosed in Patent Document 3, and the presence or absence of defects on the main surface of the substrate and the type of the defects (concave
- This is an inspection method (spatial filter method) for determining defects, convex defects, and the like.
- the defect inspection method using the two-beam interference method there is a method using the defect inspection apparatus described in Patent Document 2.
- the defect inspection method based on the two-beam interference method described in Patent Document 2 is as follows. That is, in the defect inspection method using the two-beam interference method, the light beam emitted from the light source device is converted into two sub-beams having coherence by the interference optical system. Then, the sample surface to be inspected for defects is scanned by these sub beams. When there is a defect on the sample surface, one of the two sub-beams scans the defective part, and the other sub-beam scans a normal part adjacent to the defect. A phase difference corresponding to the magnitude occurs.
- the relationship between the amplitude of the interference beam obtained by combining the sub-beams reflected on the sample surface by the interference optical system and the phase difference between the sub-beams is such that the phase difference between the two sub-beams is 0 to ⁇ (1 (Corresponding to / 4 wavelength), the amplitude of the interference beam changes from the sum of the two sub-beams to 0. If this relationship is used, the amplitude, that is, luminance information of the interference beam changes from a normal value to almost zero, so that a defect detection apparatus having extremely high detection sensitivity for a minute defect can be realized. Moreover, if the sample surface is scanned two-dimensionally with a plurality of light beams, defect detection can be performed at high speed.
- the defect inspection method using the spatial filter method there is a method using the defect inspection apparatus described in Patent Document 3.
- the defect inspection method based on the spatial filter method described in Patent Document 3 is as follows. That is, in the spatial filter type defect inspection method, a radiation beam generated from a light source is converted into a light beam array arranged in an mxn matrix by a diffraction grating, and these light beams are focused into a beam spot by an objective lens. Then, a matrix light spot array of m rows and n columns is formed on the sample to be inspected for defects. A sample to be inspected for defects is supported on a sample stage, and this sample stage is rotated and translated along a radial direction perpendicular to the rotation axis.
- the sample to be inspected is scanned with m ⁇ n light spots, and the surface of the sample is scanned with a wide band-shaped light beam composed of m ⁇ n light beams.
- the sample surface can be scanned at high speed, and the inspection time can be greatly reduced.
- the photodetector includes a light receiving element array arranged in a two-dimensional matrix and separated by a light shielding member, so that the optical system of this defect inspection method is a confocal optical system. Will be formed.
- a transfer pattern (referred to as a “light-shielding film pattern” when a light-shielding film is patterned) provided on a transfer mask has been advanced.
- the upper limit value of the size of defects allowed to exist on the main surface of the mask blank substrate is becoming smaller.
- the spatial filter type inspection method has a higher detection resolution for defects on the main surface of the substrate. For this reason, in recent years, a defect inspection for the main surface of a substrate has been increasing by a spatial filter type defect inspection apparatus.
- the spatial filter type defect inspection apparatus has a problem that the time required for the inspection is longer than that of the two-beam interference type defect inspection apparatus. For this reason, in the defect inspection of the mask blank substrate having a relatively large upper limit of the allowable defect size, there is a tendency that a two-beam interference type defect inspection apparatus is used.
- a mask blank substrate is also selected in a two-stage defect inspection process. In this case, first, a primary defect inspection is performed on the substrate by a two-beam interference type defect inspection apparatus, and only a substrate having no relatively large defect is selected. A secondary defect inspection is performed by a spatial filter type defect inspection apparatus on the substrate selected as a result of the primary defect inspection, and a substrate having no defect of a predetermined size or larger is selected as a mask blank substrate.
- the defect inspection method based on the two-beam interference method is excellent in detecting a gentle hill-shaped defect present on the surface to be measured, for example, in the case of a convex defect.
- the spatial filter type defect inspection method is excellent in detecting a defect having a steep side wall, for example, in the case of a convex defect.
- a defect inspection of a substrate even if the defect inspection apparatus determines that a defect exists on the main surface of the substrate, the defect actually exists at a predetermined position on the main surface where it is determined that the defect exists. It is known that a phenomenon that does not occur. Such a defect that is erroneously detected is called a pseudo defect.
- the cause of the detection of the pseudo defect varies depending on the inspection conditions, and therefore, it is general to take an appropriate solution for each content of the pseudo defect.
- the number of detected pseudo defects between the substrates is determined. Although no noticeable difference occurs, it has been found that when a defect inspection is performed using a two-beam interference type defect inspection apparatus, a noticeable difference may occur in the number of detected pseudo defects between the substrates.
- a defect inspection apparatus using a two-beam interference type defect inspection apparatus is subjected to a substrate in which such a phenomenon occurs, there are many defects even if the substrate can actually be used as a mask blank substrate. It was a problem because it was erroneously determined as an unacceptable substrate. In the present specification, a defect that actually exists is referred to as a true defect for comparison with a pseudo defect.
- the present invention suppresses the occurrence of a significant difference in the number of detected pseudo defects between the substrates even when the defect inspection of the main surface of the substrate is performed using the two-beam interference type defect inspection apparatus.
- An object of the present invention is to obtain a mask blank substrate and a manufacturing method thereof.
- the present invention can detect the number of pseudo defects detected between each mask blank or transfer mask even when the defect inspection of the main surface of the mask blank or transfer mask is performed using a two-beam interference type defect inspection apparatus.
- An object of the present invention is to obtain a mask blank, a transfer mask, and a method for manufacturing the same, which can suppress the occurrence of a significant difference in the thickness.
- the present inventors have determined that the roughness of a predetermined spatial frequency (or spatial wavelength) component is smaller than the inspection light source wavelength of the two-beam interference type defect inspection apparatus. It was found that it is related to the number of detected defects including pseudo defects. Therefore, the present inventors specify the spatial frequency of the roughness component that the two-beam interference type defect inspection apparatus erroneously determines as a pseudo-defect among roughness (unevenness) components on the surface of the main surface of the substrate. The inventors have found that by managing the amplitude intensity (power spectral density) at the spatial frequency, the number of detected defects including pseudo defects in the defect inspection of the two-beam interference method can be suppressed, and the present invention has been achieved.
- the present invention provides a mask blank substrate having the following configurations 1 to 4, a mask blank having the following configuration 5, and a transfer having the following configuration 6 It is a mask for. Further, the present invention provides a mask blank substrate manufacturing method characterized by the following configurations 7 to 11, a mask blank manufacturing method characterized by the following configuration 12, and the following configuration 13: This is a method for manufacturing a transfer mask.
- Configuration 1 of the present invention is a mask blank substrate composed of a substrate having two main surfaces, wherein the main surface on the side on which the transfer pattern of the mask blank substrate is formed is the transfer pattern forming region.
- the surface shape of the main surface is measured using a white interferometer in a measurement area of 2.8 mm ⁇ 2.1 mm under the condition of the number of pixels of 640 ⁇ 480, the spatial frequency calculated from the measurement result is 1.0 ⁇ .
- the main surface of the mask blank substrate on which the transfer pattern is formed has a surface shape of the main surface in the transfer pattern formation region of 2.8 mm ⁇ 2.1 mm using the white interferometer.
- the power spectral density with a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 calculated from the measurement result is 6.0 ⁇ 10 7 nm 4.
- the main surface on the side where the transfer pattern is formed has a measurement area of 693 ⁇ m ⁇ 520 ⁇ m using the white interferometer with respect to the main surface in the transfer pattern formation region.
- the surface shape in which the power spectrum density at the spatial frequency of 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 calculated from the measurement result is 3.0 ⁇ 10 5 nm 4 or less is obtained.
- Configuration 2 of the present invention detection of a pseudo defect when performing a defect inspection of a mask blank substrate using a defect inspection apparatus of a two-beam interference method can be further suppressed. Realization can be further promoted.
- the main surface on the side where the transfer pattern is formed has a measurement region of 140 ⁇ m ⁇ 105 ⁇ m using the white light interferometer with respect to the main surface in the transfer pattern formation region.
- the surface shape in which the power spectral density at the spatial frequency of 2.0 ⁇ 10 ⁇ 1 ⁇ m ⁇ 1 calculated from the measurement result is 8.0 ⁇ 10 2 nm 4 or less is obtained.
- the mask blank substrate according to Configuration 1 or 2 wherein the substrate is a mask blank substrate.
- the detection of the pseudo defect when performing the defect inspection of the mask blank substrate using the defect inspection apparatus of the two-beam interference method can be further suppressed. Realization can be further promoted.
- the main surface on the side different from the side on which the transfer pattern is formed uses the white interferometer with respect to the main surface in an area having the same size as the transfer pattern formation area.
- the measurement area of 2.8 mm ⁇ 2.1 mm is measured under the condition of the number of pixels of 640 ⁇ 480, the power spectral density of the spatial frequency 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 calculated from the measurement result is
- the mask blank substrate according to any one of Configurations 1 to 3, having a surface shape of 6.0 ⁇ 10 7 nm 4 or less.
- Configuration 4 of the present invention when a defect inspection apparatus for a mask blank is inspected using a two-beam interference type defect inspection apparatus even on the main surface on the side different from the side on which the transfer pattern is formed.
- the detection of pseudo defects can be suppressed, and thereby, fatal defects can be revealed.
- the transfer pattern forming thin film is provided on the main surface of the mask blank substrate according to any one of the first to fourth aspects on which the transfer pattern is formed. This is a mask blank.
- a two-beam interference type defect inspection apparatus can be used to form a mask blank transfer pattern. It is possible to suppress detection of a pseudo defect when performing a defect inspection of a thin film, and thereby to make a fatal defect present in a mask blank obvious.
- Configuration 6 of the present invention is a transfer mask, wherein the transfer pattern is provided on the thin film of the mask blank according to Configuration 5 described above.
- Configuration 6 of the present invention it is possible to suppress detection of pseudo defects when performing defect inspection of a transfer mask by using a defect inspection apparatus of a two-beam interference method, and thereby exist in the transfer mask. It is possible to make the fatal defect to be revealed.
- Configuration 7 of the present invention is a method for manufacturing a mask blank substrate comprising a substrate having two main surfaces, on the side on which the transfer pattern of the mask blank substrate is formed, and in the transfer pattern forming region.
- a defect inspection step of performing defect inspection on the main surface by a method using two-beam interference, and the main surface on the side where the transfer pattern of the mask blank substrate is formed is within the transfer pattern forming region.
- the spatial frequency calculated from the measurement result is 1.0 ⁇ 10.
- a mask blank substrate manufacturing method having a surface shape in which a power spectral density of ⁇ 2 ⁇ m ⁇ 1 is 6.0 ⁇ 10 7 nm 4 or less.
- a mask blank substrate having a predetermined surface shape is selected, the transfer pattern of the mask blank substrate is formed, and the main surface in the transfer pattern formation region is
- a defect inspection process for performing defect inspection by a method using two-beam interference detection of pseudo defects at the time of defect inspection by the two-beam interference method can be suppressed. Therefore, even when a two-beam interference type defect inspection is performed, it is possible to manufacture a mask blank substrate capable of realizing a fatal defect.
- the main surface of the mask blank substrate on which the transfer pattern is formed is 693 ⁇ m ⁇ 520 ⁇ m using the white interferometer with respect to the main surface in the transfer pattern formation region.
- the power spectral density of the spatial frequency 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 calculated from the measurement result is 3.0 ⁇ 10 5 nm 4. It is a manufacturing method of the mask blank substrate according to Configuration 7, which has the following surface shape.
- the configuration 8 of the present invention it is possible to further suppress the detection of the pseudo defect when performing the defect inspection of the mask blank substrate using the defect inspection apparatus of the two-beam interference method. It is possible to manufacture a mask blank substrate that can be more obvious.
- the main surface of the mask blank substrate on which the transfer pattern is formed is 140 ⁇ m ⁇ 105 ⁇ m using the white light interferometer with respect to the main surface in the transfer pattern forming region. Is measured under the condition of the number of pixels of 640 ⁇ 480, the power spectral density with a spatial frequency of 2.0 ⁇ 10 ⁇ 1 ⁇ m ⁇ 1 calculated from the measurement result is 8.0 ⁇ 10 2 nm 4. It is the manufacturing method of the mask blank board
- the ninth aspect of the present invention it is possible to further suppress the detection of the pseudo defect when performing the defect inspection of the mask blank substrate using the defect inspection apparatus of the two-beam interference method. It is possible to manufacture a mask blank substrate that can be further realized.
- the transfer pattern of the mask blank substrate is transferred by moving the substrate relative to the polishing pad of the polishing surface plate while supplying the polishing liquid.
- Configuration 10 of the present invention since a predetermined surface shape can be obtained in the mask blank substrate by providing the predetermined polishing step, the mask blank substrate can be obtained using the two-beam interference type defect inspection apparatus. Therefore, it is possible to reliably suppress the detection of the pseudo defects when performing the defect inspection, and it is possible to manufacture a mask blank substrate that can reliably expose the fatal defects.
- Configuration 11 of the present invention is the method for manufacturing a mask blank substrate according to Configuration 10, wherein the polishing liquid contains colloidal silica having an average particle diameter D50 of 100 nm or less.
- a predetermined surface shape can be more reliably obtained on the mask blank substrate by using a predetermined polishing liquid in a predetermined polishing step. Therefore, it is possible to more reliably suppress the detection of pseudo defects when performing a defect inspection of a mask blank substrate using a defect inspection apparatus of a two-beam interference method.
- a mask blank substrate that can be reliably achieved can be manufactured.
- Configuration 12 In the configuration 12 of the present invention, pattern formation is performed on the main surface on the side where the transfer pattern of the mask blank substrate manufactured by the method for manufacturing a mask blank substrate according to any one of configurations 7 to 11 is formed. It is the manufacturing method of the mask blank characterized by including the process of providing the thin film for an electric field.
- the mask blank substrate manufactured by the above-described manufacturing method can have a main surface with a predetermined surface shape. For this reason, it is possible to suppress the detection of a pseudo defect when performing a defect inspection of a thin film for forming a mask blank transfer pattern by using a defect inspection apparatus of a two-beam interference method. A mask blank capable of revealing defects can be manufactured.
- Configuration 13 of the present invention is a method for manufacturing a transfer mask, comprising the step of forming the transfer pattern on the thin film of the mask blank manufactured by the mask blank manufacturing method according to Configuration 12.
- the transfer mask since the transfer mask is manufactured using a mask blank substrate having a main surface having a predetermined surface shape, the transfer mask can be transferred using a two-beam interference type defect inspection apparatus. It is possible to suppress the detection of a pseudo defect when performing a defect inspection of the mask, and thereby it is possible to manufacture a transfer mask capable of revealing a fatal defect existing in the transfer mask.
- the present invention even when a defect inspection of the main surface of a substrate is performed using a two-beam interference type defect inspection apparatus, it is possible to suppress a significant difference in the number of detected pseudo defects between the substrates.
- a mask blank substrate and a method for manufacturing the same are provided. Further, according to the present invention, even when the defect inspection of the main surface of the mask blank or the transfer mask is performed using the defect inspection apparatus of the two-beam interference method, the pseudo defect is detected between the mask blanks or the transfer mask.
- a mask blank and a transfer mask that can suppress the occurrence of a significant difference in the number of detections, and a method of manufacturing the same.
- the transfer mask of the present invention can be used as a transmissive transfer mask.
- FIG. 1 is a perspective view showing a mask blank substrate according to an embodiment of the present invention. It is a cross-sectional schematic diagram which shows the mask blank substrate which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram which shows an example of a structure of the mask blank which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram which shows an example of a structure of the transfer mask which concerns on one Embodiment of this invention. The figure which shows the result of having measured the power spectrum density of the area
- FIG. 6 is a diagram showing the result of measuring the power spectral density of a region of 693 ⁇ m ⁇ 520 ⁇ m on the main surface of the mask blank substrate of Examples 1 to 4 and Comparative Example 1 with a white interferometer at 640 ⁇ 480 pixels.
- FIG. 6 is a diagram showing the result of measuring the power spectral density of a 140 ⁇ m ⁇ 105 ⁇ m region on the main surface of the mask blank substrate of Examples 1 to 4 and Comparative Example 1 with a white interferometer at 640 ⁇ 480 pixels.
- It is a schematic diagram of the cross-sectional structure of a polishing pad.
- It is a block diagram of a double-side polishing apparatus.
- It is a block diagram of the compression tester used for the measurement of the amount of compressive deformation of a polishing pad.
- It is a schematic diagram for demonstrating the measuring method of the amount of compressive deformation of a polishing pad.
- FIG. 1A is a perspective view showing a mask blank substrate 10 of the present embodiment.
- FIG. 1B is a schematic cross-sectional view showing the mask blank substrate 10 of the present embodiment.
- the mask blank substrate 10 (or simply referred to as the substrate 10) is a rectangular plate-like body, and has two opposing main surfaces 2 and an end surface 1.
- the two opposing main surfaces 2 are the upper surface and the lower surface of this plate-like body, and are formed so as to oppose each other. At least one of the two opposing main surfaces 2 is a main surface on which a transfer pattern is to be formed.
- the end face 1 is a side face of the plate-like body and is adjacent to the outer edge of the opposing main surface 2.
- the end surface 1 has a planar end surface portion 1d and a curved end surface portion 1f.
- the planar end surface portion 1d is a surface that connects the side of one opposing main surface 2 and the side of the other opposing main surface 2, and includes a side surface portion 1a and a chamfered slope portion 1b.
- the side surface portion 1a is a portion (T surface) substantially perpendicular to the opposing main surface 2 in the planar end surface portion 1d.
- the chamfered slope portion 1b is a chamfered portion (C surface) between the side surface portion 1a and the opposing main surface 2, and is formed between the side surface portion 1a and the opposing main surface 2.
- the curved end surface portion 1f is a portion (R portion) adjacent to the vicinity of the corner portion 10a of the substrate 10 when the substrate 10 is viewed in plan, and includes a side surface portion 1c and a chamfered slope portion 1e.
- the plan view of the substrate 10 refers to, for example, viewing the substrate 10 from a direction perpendicular to the opposing main surface 2.
- substrate 10 is the intersection vicinity of two sides in the outer edge of the opposing main surface 2, for example. The intersection of two sides may be the intersection of the extension lines of the two sides.
- the curved end surface portion 1 f is formed in a curved shape by rounding the corner 10 a of the substrate 10.
- the present invention provides a pattern forming thin film (such as a light-shielding film 51) on at least a main surface on which a transfer pattern is formed, that is, a transmissive mask blank 50 as described later.
- the main surface on the side where is formed has a specific power spectral density in a specific spatial frequency region (Power Spectrum Density: PSD).
- PSD power spectral density
- the surface of the mask blank substrate 10 is subjected to Fourier transform, for example, on the surface of the substrate main surface obtained by measuring with a white interferometer or an atomic force microscope, so that the surface of the unevenness is amplitude intensity at a predetermined spatial frequency.
- This represents the measurement data of the unevenness (that is, the fine shape of the main surface of the substrate) as a sum of waves having a predetermined spatial frequency, that is, the surface shape of the substrate is divided into waves having a predetermined spatial frequency.
- Nx and Ny are the numbers of data in the x and y directions.
- u 0, 1, 2,... Nx ⁇ 1
- v 0, 1, 2,... Ny ⁇ 1
- the spatial frequency f is given by the following equation (3).
- This power spectrum analysis is excellent in that it can grasp the change in the surface state of the substrate not only as a simple change in height but also as a change in its spatial frequency. This is a technique for analyzing the influence of reaction on the main surface of the substrate.
- the mask blank substrate 10 of the present invention is configured so that a 2.8 mm ⁇ 2.1 mm region on the main surface on the side where the transfer pattern is formed is measured with a white interferometer.
- the power spectral density (PSD) at a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 obtained by measurement at 640 ⁇ 480 is set to 6.0 ⁇ 10 7 nm 4 or less.
- a white interferometer As a device for measuring the surface state of a substrate, a white interferometer is known.
- a white interferometer is, for example, a white light with less coherence, and a light path interferometer such as a Mirau type or a Michelson type is used as a light source.
- a device that uses a technique for finding the position where the maximum is obtained by vertical scanning of the interferometer objective lens As an example of a white interferometer, for example, a non-contact surface shape measuring device “NewView 7000 Series” manufactured by Zygo Corporation can be cited.
- the area of 2.8 mm ⁇ 2.1 mm is the center area of the mask blank substrate 10.
- the center is an intersection of diagonal lines of the rectangle. That is, the intersection and the center in the region (the center of the region is the same as the center of the substrate) coincide.
- a thin film such as a pattern forming thin film (for example, the light shielding film 51).
- the PSD data in each spatial frequency region described above is obtained by observation under measurement conditions (measurement field of view, etc.) that have high reliability.
- the main surface on the side on which the transfer pattern is formed has the transfer pattern formation region
- the spatial frequency calculated from the measurement result is 5.0 ⁇ 10 ⁇ . It is preferable to have a surface shape with a power spectral density of 2 ⁇ m ⁇ 1 of 3.0 ⁇ 10 5 nm 4 or less.
- the mask blank substrate 10 of the present invention preferably has a side on which the transfer pattern is formed in addition to observations at spatial frequencies of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 and 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1.
- the mask blank substrate 10 has a surface shape in which the calculated power spectral density at a spatial frequency of 2.0 ⁇ 10 ⁇ 1 ⁇ m ⁇ 1 is 8.0 ⁇ 10 2 nm 4 or less.
- the main surface on the side different from the side on which the transfer pattern is formed be a predetermined spatial frequency in a predetermined spatial frequency, similarly to the main surface in the transfer pattern formation region. It is preferable to be in the range of power spectral density.
- the main surface on the side different from the side on which the transfer pattern is formed is compared with the main surface in a region having the same size as the transfer pattern forming region.
- a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 calculated from the measurement result It is preferable to have a surface shape with a power spectral density of 6.0 ⁇ 10 7 nm 4 or less.
- the defect inspection apparatus In order to manufacture the transmission type transfer mask 60, it is necessary to inspect the main surfaces of the mask blank substrate 10, the mask blank 50, and the transfer mask 60 for defects.
- the defect inspection apparatus include a defect inspection method using a two-beam interference method and a defect inspection method using a spatial filter method.
- the mask blank substrate 10, the mask blank 50, and the transfer mask 60 of the present invention are measured between the mask blank substrates 10 and between the mask blanks 50 when the defect inspection of their main surfaces is measured by the two-beam interference method.
- the mask blank substrate 10 the mask blank 50, and the transfer mask 60 of the present invention, the number of detected defects including pseudo defects is reduced, and thereby the fatal defects that should not be detected are reliably detected. be able to. This makes it possible to make a fatal defect noticeable. If a fatal defect is detected, it is removed, or a thin film pattern (transfer pattern such as a light-shielding film pattern 51a or the like is transferred onto the fatal defect in a transfer mask 60 described later.
- the mask can be designed so as to come up with a variety of treatments.
- Rms ⁇ Surface roughness (Rms)> Rms (Root means square) which is a representative surface roughness index in the mask blank substrate 10 is a root mean square roughness, and is a square root of a value obtained by averaging the squares of deviations from the average line to the measurement curve. is there. That is, Rms is expressed by the following formula (1).
- Rms can be obtained by measuring an area of 1 ⁇ m ⁇ 1 ⁇ m on the main surface of the mask blank substrate 10 with an atomic force microscope.
- the above-mentioned root mean square roughness is preferably less than 0.13 nm, more preferably 0.12 nm or less, and still more preferably 0.10 nm or less.
- the root mean square roughness is a numerical value when calculated from a measurement result by an atomic force microscope with respect to a 1 ⁇ m ⁇ 1 ⁇ m square inner region on the main surface of the substrate.
- the main surface on the side where the transfer pattern is formed is subjected to surface processing so as to have high flatness from the viewpoint of obtaining at least pattern transfer accuracy and position accuracy. preferable.
- the main surface opposite to the side on which the transfer pattern is formed needs to be as flat as possible.
- the mask blank substrate 10 of the present invention described above can be manufactured as follows.
- the method for manufacturing a mask blank substrate 10 according to the present invention is a method for manufacturing a mask blank substrate 10 composed of a substrate having two main surfaces, on the side where the transfer pattern of the mask blank substrate 10 is formed. And a defect inspection step of performing a defect inspection on the main surface in the transfer pattern formation region by a method using two-beam interference. Further, the main surface of the mask blank substrate 10 on the side where the transfer pattern is formed has a predetermined measurement region as described above with respect to the main surface in the transfer pattern formation region using a white interferometer. When the measurement is performed under the condition of a predetermined number of pixels, the surface shape is such that the power spectral density of a predetermined spatial frequency calculated from the measurement result is a predetermined value or less.
- the manufacturing method of the mask blank substrate 10 of the present invention includes a defect inspection process for performing a defect inspection by a method using two-beam interference, thereby suppressing detection of a pseudo defect in the defect inspection of the two-beam interference method. Can do. Thereby, it is possible to manufacture the mask blank substrate 10 capable of realizing the fatal defect.
- the glass substrate material examples include glass materials such as synthetic quartz glass, soda lime glass, aluminosilicate glass, low thermal expansion glass (for example, SiO 2 —TiO 2 glass), and crystallized glass on which ⁇ quartz solid solution is deposited. It is possible to use. As a material of the glass substrate, it is preferable to use synthetic quartz glass.
- the mask blank substrate 10 of the present invention has a main surface on the side where the transfer pattern is formed, a predetermined surface shape, that is, a measurement area of 2.8 mm ⁇ 2.1 mm using a white interferometer is 640 ⁇ 480.
- a predetermined surface shape that is, a measurement area of 2.8 mm ⁇ 2.1 mm using a white interferometer is 640 ⁇ 480.
- the surface shape in which the power spectral density (PSD) at a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 calculated from the measurement result is 6.0 ⁇ 10 7 nm 4 or less It can manufacture by carrying out surface processing so that it may become.
- the surface processing method of the mask blank substrate 10 is known and can be employed without any particular limitation in the present invention.
- Examples of the surface processing method for the mask blank substrate 10 include magnetic viscoelastic fluid polishing (Magneto Rheological Finishing: MRF), chemical mechanical polishing (Chemical Mechanical Polishing: CMP), gas cluster ion beam etching (Gas Cluster Ion). Examples thereof include beam etching (GCIB) and dry chemical planarization (DCP) using local plasma etching.
- MRF magnetic viscoelastic fluid polishing
- CMP chemical mechanical polishing
- Gas Cluster Ion gas cluster ion beam etching
- GCIB beam etching
- DCP dry chemical planarization
- CMP uses a small-diameter polishing pad and a polishing agent (containing abrasive grains such as colloidal silica), and controls the residence time of the contact portion between the small-diameter polishing pad and the workpiece (mask blank substrate 10), This is a local processing method that mainly polishes the convex portion on the surface of the workpiece.
- GCIB generates gas cluster ions by ejecting gaseous reactive substances (source gas) at normal temperature and pressure while adiabatic expansion in a vacuum device, and ionizing them by electron irradiation.
- DCP is a local processing method in which dry etching is locally performed by locally performing plasma etching and controlling the amount of plasma etching according to the degree of convexity.
- the following method can be used.
- the mask blank substrate 10 is relatively moved while supplying the polishing liquid on the polishing pad 17 of the polishing surface plate as a surface processing method before the defect inspection step. It is preferable to provide a polishing step for polishing the main surface of the mask blank substrate 10 on which the transfer pattern is formed. Since the manufacturing method of the mask blank substrate 10 of the present invention includes a predetermined polishing step, a predetermined surface shape can be obtained in the mask blank substrate 10, so a two-beam interference type defect inspection apparatus is used. Therefore, it is possible to manufacture the mask blank substrate 10 that can surely suppress the detection of the pseudo defects when the defect inspection of the mask blank substrate 10 is performed, and thereby can surely reveal the fatal defects. it can.
- a preferable method as the surface processing method of the mask blank substrate 10 is as follows. That is, first, the mask blank substrate 10 is set on a surface plate provided with the polishing pad 17 on the rotating surface. Next, while supplying a polishing liquid containing abrasive grains of silica or colloidal silica between the polishing pad 17 and the mask blank substrate 10, the substrate is moved relative to the polishing surface of the polishing pad 17, Polish the main surface. At this time, the polishing pad 17 is composed of at least a base material 17A and a nap layer 17B made of a foamed resin formed on the base material 17A and having pores on the surface, and the amount of compressive deformation of the polishing pad 17 is 330 ⁇ m.
- the 100% modulus of the resin forming the nap layer 17B is preferably 3 MPa or more and 14 MPa or less.
- the main surface of the mask blank substrate 10 can be set within a predetermined power spectral density range at a predetermined spatial frequency. Therefore, it is possible to suppress the detection of a pseudo defect when performing a defect inspection of the mask blank substrate 10 using a defect inspection apparatus of a two-beam interference method, thereby making it possible to reveal a fatal defect. it can.
- FIG. 7 is a schematic diagram showing a cross-sectional configuration of the polishing pad 17 used in the surface processing method.
- the polishing pad 17 used for the polishing treatment was formed on a base material 17A made of a nonwoven fabric, a resin film such as PET resin, and the like, and was foamed with an opening on the surface formed on the base material 17A.
- a nap layer 17B made of a resin.
- a buffer layer can be provided between the base material 17A and the nap layer 17B. The buffer layer is provided to adjust the amount of compressive deformation in the entire polishing pad 17, and is preferably a foamed resin.
- pore 18 which is a trace of foaming.
- the internal cross-sectional structure of the polishing pad 17 (particularly, the nap layer 17B) is merely depicted as an image, and the actual internal structure is not necessarily accurately depicted.
- the foamed resin refers to, for example, a resin that is finely dispersed in a synthetic resin and molded into a foamed or porous shape containing countless fine bubbles inside. It can also be defined as a heterogeneous dispersion system of a certain synthetic resin and gas.
- urethane is widely used as the foamed resin (nap layer 17B).
- the foamed resin (nap layer 17B) is a polyurethane resin, a polycarbonate resin, a polyester resin, a polyether resin, or a resin obtained by blending these resins can be used as a raw material resin constituting the polyurethane resin. .
- Examples of the polishing pad 17 provided with the base material 17A and the nap layer 17B include a suede type and a urethane foam type.
- the suede type polishing pad 17 polyurethane is coated (laminated) on the base material 17 ⁇ / b> A, a foamed layer is grown in the polyurethane, a surface portion is removed, and an opening is provided in the foamed layer.
- the urethane foam type polishing pad 17 is obtained by slicing a foamed urethane block, and is bonded to the base material 17A so that the polishing pad 17 includes the base material 17A and the foamed resin layer (nap layer 17B). It can be.
- the thickness of the nap layer 17B is preferably about 300 ⁇ m to 1000 ⁇ m, for example.
- the opening diameter of the pores in the nap layer 17B is preferably about 40 ⁇ m to 100 ⁇ m, for example.
- a characteristic configuration is that a combination of the amount of compressive deformation of the polishing pad 17 and the modulus of the resin forming the nap layer 17B is appropriately selected. That is, in this polishing pad 17, it is preferable that the amount of compressive deformation of the polishing pad 17 is 330 ⁇ m or less, and the 100% modulus of the resin forming the nap layer 17B is 3 MPa or more and 14 MPa or less.
- the compression ratio (%) [(t 0 ⁇ t 1 ) / t 0 ] ⁇ 100.
- the compression deformation amount is measured by placing a polishing pad 17 on a surface plate and pressing an indenter ( ⁇ 10 mm) from the upper part of the polishing pad 17 at a stroke speed of 0.1 mm / min. Use a tester.
- the resin modulus is an index representing the hardness of the resin itself.
- the value is expressed as the force (tensile stress) applied when the non-foamed resin film is stretched twice, and the harder the resin, the more force is required to stretch the numerical value. The softer the resin, the smaller the value.
- Resin modulus is basically determined by the hard segment content, not the resin system (polycarbonate, polyester, polyether, etc.). Specifically, since polyurethane has a soft segment and a hard segment and has a microphase separation structure, the hardness of the resin is determined by the ratio (amount) of the hard segment.
- the soft segment is a polymer polyol and is a portion where the resin (polymer) is weakly aggregated. The soft segment can be adjusted by the blend ratio of the resin system (polycarbonate, polyester, polyether, etc.) and the resin.
- the amount of compressive deformation of the polishing pad 17 applied to the polishing process is 330 ⁇ m or less.
- the 100% modulus of the resin forming the nap layer 17B is 3 MPa or more and 14 MPa or less.
- the amount of compressive deformation of the polishing pad 17 exceeds 330 ⁇ m, for example, the undulation PV value becomes 10 nm or more, and the undulation cannot be suppressed.
- the 100% modulus of the resin forming the nap layer is less than 3 MPa, it is difficult to suppress swell. Further, when the 100% modulus exceeds 14 MPa, undulation can be suppressed, but there is a problem that many scratch defects are generated on the main surface of the substrate after polishing.
- the amount of compressive deformation of the polishing pad 17 is particularly preferably 60 ⁇ m or more and 300 ⁇ m or less, and more preferably 75 ⁇ m or more and 260 ⁇ m or less.
- the 100% modulus of the resin forming the nap layer is particularly preferably 6 MPa or more and 12 MPa or less.
- the main surface of the mask blank substrate 10 can be set within a predetermined power spectral density range at a predetermined spatial frequency. Therefore, it is possible to suppress the detection of a pseudo defect when performing a defect inspection of the mask blank substrate 10 using a defect inspection apparatus of a two-beam interference method, thereby making it possible to reveal a fatal defect. it can.
- a polishing process is performed by applying the polishing pad 17 having the above-mentioned characteristics. Specifically, a substrate is set on a surface plate provided with a polishing pad 17 on a rotating surface, and a polishing liquid containing silica or colloidal silica abrasive grains is supplied between the polishing pad 17 and the substrate, In this polishing step, the substrate is moved relative to the polishing surface of the polishing pad 17 to polish the main surface of the substrate.
- Such a polishing step can be performed using, for example, a planetary gear type double-side polishing apparatus as shown in FIG.
- the double-side polishing apparatus shown in FIG. 8 meshes with the sun gear 12, the internal gear 13 disposed concentrically on the outer side thereof, the sun gear 12 and the internal gear 13, and the sun gear 12 and the internal gear 13.
- An upper surface plate 15 and a lower surface plate to which a carrier 14 that revolves and rotates according to rotation and a polishing pad 17 that can hold a workpiece (mask blank substrate 10) held by the carrier 14 are attached.
- 16 and a polishing liquid supply unit (not shown) for supplying a polishing liquid between the upper surface plate 15 and the lower surface plate 16.
- the workpiece to be polished that is, the substrate 10 (glass substrate)
- the substrate 10 glass substrate
- the carrier 14 revolves and rotates according to the rotation of the sun gear 12 and the internal gear 13 while supplying the polishing liquid between the 16 polishing pads 17 and the substrate 10
- the upper and lower main surfaces of the substrate 10 are moved. Polished.
- both main surfaces of the substrate 10 can be polished simultaneously.
- the substrate 10 can also be polished one side at a time on both main surfaces of the substrate with a single-side polishing apparatus.
- this surface processing method it is desirable to perform a rough polishing process, a precision polishing process, and an ultra-precision polishing process using, for example, the above double-side polishing apparatus.
- the type and particle size of the abrasive used can be appropriately selected according to the substrate material and the flatness to be obtained.
- the abrasive include cerium oxide, zirconium oxide, silica, colloidal silica, and the like.
- the particle diameter of the abrasive is several tens of nm to several ⁇ m.
- the manufacturing method of the mask blank substrate 10 of the present invention has an optimum configuration when the substrate is polished with a polishing liquid containing silica or colloidal silica.
- the abrasive grains used in the surface processing method and the like are colloidal silica.
- the polishing liquid containing colloidal silica contains water and further contains a predetermined additive (for example, an alkali compound).
- the additive has a function of protecting the surface of the surface to be polished and suppressing an attack by the abrasive grains on the surface to be polished.
- the additive contained in the polishing liquid is preferably at least one selected from hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and pullulan. Two or more of these can be mixed and used. Considering detergency, the additive contained in the polishing liquid is most preferably hydroxyethyl cellulose.
- the alkali compound contained in the polishing liquid as an additive include tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide.
- the alkali compound contained in the polishing liquid as an additive is preferably ammonia.
- the rough polishing process is performed for the purpose of removing scratches on the main surface of the substrate formed in the grinding process and maintaining the flatness obtained in the grinding process.
- the average grain size of the abrasive grains is about 1 to 3 ⁇ m. It is the process of grind
- the material of the abrasive grains is appropriately selected according to the material of the substrate.
- the polishing pad 17 used in the rough polishing step is preferably a hard polisher from the viewpoint of maintaining flatness.
- the precision polishing process is performed for the purpose of mirror-finishing the substrate without surface defects such as scratches, and relatively small abrasive grains having an average grain size of about 1 ⁇ m or less (for example, 10 nm to 1 ⁇ m). It is the process of grind
- the material of the abrasive grains is appropriately selected according to the material of the substrate as described above. Cerium oxide is preferred from the viewpoint of obtaining a smooth substrate main surface with a small average particle diameter.
- the polishing pad 17 used in the precision polishing step is preferably a soft or ultra-soft polisher from the viewpoint of mirroring.
- the ultra-precise polishing process is performed for the purpose of further mirror-finishing the substrate (improving the surface roughness), and the average particle size of the abrasive grains is very small, about 500 nm or less (for example, 10 nm to 500 nm).
- This is a step of polishing using abrasive grains.
- the material of the abrasive grains is appropriately selected according to the material of the substrate as described above. Silica or colloidal silica is preferable, and colloidal silica is particularly preferable from the viewpoint of obtaining a smooth substrate main surface having a small average particle diameter.
- the polishing pad 17 used in the ultra-precision polishing step is preferably a soft or ultra-soft polisher from the viewpoint of further mirroring, and in the present invention, it is possible to reduce waviness and obtain a predetermined spatial frequency.
- the polishing pad 17 having the above-described compression deformation amount and 100% modulus value is used.
- the polishing liquid used in the predetermined polishing step preferably contains colloidal silica having an average particle diameter D50 (particle size with an integrated value of 50% of all particles) of 100 nm or less.
- D50 particle size with an integrated value of 50% of all particles
- the surface shape information measuring step for measuring surface shape information (for example, uneven shape) on the main surface of the glass substrate, and the measurement results obtained in the surface shape information measuring step Based on this, a local processing step for locally processing by setting processing conditions for each location on the main surface so as to obtain a desired flatness, and after the local processing step, finish polishing is performed so as to obtain a desired smoothness. It is preferable to perform a final polishing step.
- a local processing step for locally processing by setting processing conditions for each location on the main surface so as to obtain a desired flatness, and after the local processing step, finish polishing is performed so as to obtain a desired smoothness. It is preferable to perform a final polishing step.
- a local processing applicable in a local processing process what was mentioned above is applicable.
- the finish polishing step is performed for the purpose of removing a rough surface or a work-affected layer on the main surface of the glass substrate, and the surface that needs to be removed on the main surface of the glass substrate. If no roughening or work-affected layer has occurred, finish polishing is not particularly required.
- a polishing method that improves the surface roughness while maintaining the flatness obtained in the local processing step is preferable.
- a polishing tool surface such as the polishing pad 17 is brought into contact with the main surface of the glass substrate and precision polishing is performed with a polishing liquid, or the glass substrate main surface and the polishing tool surface are not directly in contact with each other.
- a non-contact polishing method for example, float polishing method, EEM (Elastic-Emission-Machining) method
- polishing is performed by the action of the working fluid.
- catalyst-based etching (CARE (Catalyst-Referred Etching)
- CARE Catalyst-Referred Etching
- the present invention is a mask blank 50 characterized in that a thin film for forming a transfer pattern is provided on the main surface of the mask blank substrate 10 on the side where the transfer pattern is formed.
- a transfer pattern of the mask blank 50 can be obtained using a two-beam interference type defect inspection apparatus. It is possible to suppress the detection of pseudo defects when performing a defect inspection of the forming thin film, and thereby to make the fatal defects present in the mask blank 50 obvious.
- FIG. 2 is a schematic cross-sectional view showing an example of the configuration of the mask blank 50 (transmission mask blank 50) of the present invention.
- the mask blank 50 of the present invention can be manufactured as follows. That is, the mask blank 50 of the present invention is provided with a pattern forming thin film (such as a light shielding film 51) on the main surface of the mask blank substrate 10 manufactured as described above on the side where the transfer pattern is formed. Can be manufactured. In the example of the mask blank 50 shown in FIG. 2, an etching mask film 52 is further formed on the surface of the light shielding film 51.
- the mask blank 50 of the present invention can be applied to the mask blank 50 shown in the following (1) to (3), for example.
- Binary mask blank 50 including a light shielding film 51 made of a material containing a transition metal The binary mask blank 50 has a light shielding film 51 (thin film) on the main surface of the substrate.
- the light shielding film 51 is made of chromium, tantalum, ruthenium, tungsten, titanium, hafnium, molybdenum, nickel, vanadium. , Zirconium, niobium, palladium, rhodium, tin, indium and other transition metal elements or a material containing a compound thereof.
- the light shielding film 51 comprised with the tantalum compound which added 1 or more types of elements chosen from elements, such as oxygen, nitrogen, and boron, to tantalum is mentioned.
- the light shielding film 51 has a two-layer structure of a light shielding layer and a front surface antireflection layer, or a three-layer structure in which a back surface antireflection layer is added between the light shielding layer and the substrate.
- Phase shift mask blank provided with a translucent film made of a material containing a compound of silicon, or a material containing a compound of a transition metal and silicon (including transition metal silicide, particularly molybdenum silicide)
- a phase shift mask blank Includes a halftone phase shift mask blank having a light semi-transmissive film (thin film) on the main surface of the substrate.
- the halftone phase shift mask is manufactured by patterning the light semi-transmissive film of the halftone phase shift mask blank to provide a shifter portion.
- phase shift mask in order to prevent a pattern defect of the transferred substrate due to the light semi-transmissive film pattern formed in the transfer region based on the light transmitted through the light semi-transmissive film, the light semi-transmissive film is formed on the main surface of the substrate. And a light-shielding film (light-shielding band) thereon.
- mask blanks for Levenson type phase shift masks and enhancer type phase shift masks which are substrate digging types in which a shifter portion is provided by digging a substrate by etching or the like. .
- the light-semitransmissive film of the halftone phase shift mask blank transmits light having an intensity that does not substantially contribute to exposure (for example, 1% to 30% with respect to the exposure wavelength).
- a phase difference (for example, 180 degrees) is generated.
- Light that has passed through the light semi-transmission part is formed by a light semi-transmission part obtained by patterning the light semi-transmission film, and a light transmission part that does not have the light semi-transmission film and transmits light having an intensity that substantially contributes to exposure Can be made to have a substantially inverted relationship with respect to the phase of the light transmitted through the light transmitting portion.
- the contrast that is, the resolution of the boundary between the light semi-transmissive part and the light transmissive part can be improved.
- This light semi-transmissive film is made of a material containing a compound of, for example, a transition metal and silicon (including a transition metal silicide), and includes a material mainly composed of these transition metal and silicon, and oxygen and / or nitrogen.
- a transition metal molybdenum, tantalum, tungsten, titanium, hafnium, nickel, vanadium, zirconium, niobium, palladium, ruthenium, rhodium, chromium, or the like is applicable.
- the light semi-transmissive film may be formed of a material containing silicon and nitrogen. In this case, it is preferable that the light semi-transmissive film has a structure in which one or more combinations of a low transmission layer having a relatively low nitrogen content and a high transmission layer having a relatively high nitrogen content are stacked.
- the material of the light semi-transmissive film contains a transition metal and silicon, so that the material of the light-shielded film has etching selectivity with respect to the light semi-transmissive film ( It is preferably composed of chromium (having etching resistance) or a chromium compound in which elements such as oxygen, nitrogen, and carbon are added to chromium.
- the Levenson type phase shift mask is manufactured from a mask blank having the same configuration as that of the binary type mask blank 50, the configuration of the thin film for pattern formation is the same as that of the light shielding film 51 of the binary type mask blank 50.
- the light semi-transmissive film of the mask blank for the enhancer-type phase shift mask transmits light having an intensity that does not substantially contribute to exposure (for example, 1% to 30% with respect to the exposure wavelength). This is a film having a small phase difference generated in the exposure light (for example, a phase difference of 30 degrees or less, preferably 0 degrees), and this is different from the light semi-transmissive film of the halftone phase shift mask blank.
- the material of this light semi-transmissive film includes the same elements as the light semi-transmissive film of the halftone type phase shift mask blank, but the composition ratio and film thickness of each element have a predetermined transmittance and predetermined ratio to the exposure light. The phase difference is adjusted to be small.
- Binary mask blank 50 provided with a light shielding film 51 made of a material containing a compound of transition metal, transition metal and silicon (including transition metal silicide, particularly molybdenum silicide).
- the light shielding film 51 (thin film) is made of a material containing a transition metal and silicon compound.
- the light shielding film 51 (thin film) is made of a material mainly composed of transition metal and silicon, and oxygen and / or nitrogen.
- the light shielding film 51 is made of a material mainly composed of a transition metal and oxygen, nitrogen and / or boron.
- the transition metal molybdenum, tantalum, tungsten, titanium, hafnium, nickel, vanadium, zirconium, niobium, palladium, ruthenium, rhodium, chromium, or the like is applicable.
- the light shielding film 51 is formed of a molybdenum silicide compound, a two-layer structure of a light shielding layer (MoSiN, etc.) and a surface antireflection layer (MoSiN, etc.), and a back surface between the light shielding layer and the substrate.
- an etching mask film 52 may be provided on the light shielding film 51.
- This etching mask film 52 has etching selectivity (has etching resistance) with respect to the etching of the light shielding film 51 containing transition metal silicide.
- chromium or a material made of a chromium compound in which elements such as oxygen, nitrogen, and carbon are added to chromium are added to chromium.
- FIG. 3 is a schematic cross-sectional view of an example of the configuration of the transfer mask 60 of the present invention.
- the transfer mask 60 of the present invention can be manufactured by forming a transfer pattern on the thin film of the mask blank 50 manufactured by the method of manufacturing the mask blank 50 of the present invention.
- a light shielding film pattern 51 a (transfer pattern) is formed on the main surface of the mask blank substrate 10.
- the transfer pattern can be formed on the thin film by using a known method.
- a transfer pattern such as a circuit pattern based on the transfer pattern of the transfer mask 60 is applied to a resist film formed on a transfer target such as a semiconductor substrate by a lithography process using the transfer mask 60 and a predetermined exposure apparatus.
- the semiconductor device in which various patterns such as wirings are formed on the semiconductor substrate can be manufactured by transferring and performing various other processes.
- a reference mark can be formed on the mask blank substrate 10 and the mask blank 50 described above, and the coordinates of the reference mark and the position of the fatal defect detected by the high sensitivity defect inspection apparatus can be managed.
- the transfer mask 60 When producing the transfer mask 60 based on the position information (defect data) of the obtained fatal defect, there is a fatal defect based on the above-described defect data and transferred pattern (circuit pattern) data.
- the drawing data can be corrected so that the light-shielding film pattern 51a (transfer pattern) is formed at the existing location, and defects can be reduced.
- Example 1 ⁇ Production of Mask Blank Substrate 10> Synthetic quartz glass having a size of 152.4 mm ⁇ 152.4 mm and a thickness of 6.35 mm was prepared as the mask blank substrate 10 of Example 1, and the rough polishing process, the precision polishing process, and the ultra-precision process were performed as follows. A polishing step was performed.
- Rough Polishing Step 10 synthetic quartz glass substrates, whose end surfaces were chamfered and ground by a double-sided lapping device, were set in a double-side polishing device, and the rough polishing step was performed under the following polishing conditions. The processing load and polishing time were adjusted as appropriate. Polishing liquid: Cerium oxide (average particle size 2 to 3 ⁇ m) + water Polishing pad: Hard polisher (urethane pad) After the rough polishing step, the glass substrate was immersed in a cleaning tank (ultrasonic application) in order to remove the abrasive grains adhering to the glass substrate and cleaned.
- a cleaning tank ultrasonic application
- polishing liquid Polishing liquid containing water, colloidal silica (average particle diameter D50: 18 nm) and additives (hydroxyethyl cellulose and alkali compound [ammonia]). pH: 10.5.
- Polishing pad 17 A polishing pad 17 having a pad structure of PET (base material 17A) / nap layer 17B, an amount of compressive deformation of 274 ⁇ m, and a 100% modulus of the nap layer 17B of 3.0 MPa is used.
- the base material 17A of the polishing pad 17 is a PET resin film, and the nap layer 17B is made of a polyurethane resin.
- the amount of compressive deformation of the polishing pad 17 and the 100% modulus of the nap layer 17B were measured by the method described above.
- the substrate was washed with a low-concentration silicic acid solution and rinsed with pure water.
- the mask blank substrate 10 of Example 1 was manufactured.
- FIG. 5 shows the result of power spectrum analysis in which a measurement region 693 ⁇ m ⁇ 520 ⁇ m (pixel number 640 ⁇ 480) was measured, and FIG.
- FIG. 5 shows the result of power spectrum analysis in which a measurement region 140 ⁇ m ⁇ 105 ⁇ m (pixel number 640 ⁇ 480) was measured. It is shown in FIG. 4 to 6, the thick lines indicating the values of the spatial frequencies are the spatial frequencies 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 , 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 and 2.0 ⁇ 10 ⁇ 1 from the left. ⁇ m ⁇ 1 is shown.
- the power spectrum density at a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 1.3 ⁇ 10 7 nm 4 .
- the power spectrum density at a spatial frequency of 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 3.2 ⁇ 10 4 nm 4 . It was lower than 3.0 ⁇ 10 5 nm 4 (FIG. 5).
- the power spectrum density at a spatial frequency of 2.0 ⁇ 10 ⁇ 1 ⁇ m ⁇ 1 is 2.1 ⁇ 10 2 nm 4 .
- ⁇ Defect inspection> Using a two-beam interference method (inspection light source wavelength 488 nm) defect inspection apparatus (“MAGICS M1320” manufactured by Lasertec Corporation), 132 mm ⁇ on the main surface of the mask blank substrate 10 of Example 1 manufactured as described above. A 132 mm area was inspected for defects.
- the inspection sensitivity condition of this defect inspection apparatus was a sensitivity at which polystyrene latex (PSL) particles having a diameter of 150 nm dispersed on the main surface of the glass substrate could be detected.
- PSL particles have such a characteristic that the probability that the particles are close to each other within 1 mm is 1% or less.
- the substrate was rotated 90 degrees, and a 132 mm ⁇ 132 mm region on the main surface of the mask blank substrate 10 manufactured as described above was inspected.
- the first defect inspection is referred to as “0-degree defect inspection”
- the defect inspection performed by rotating the substrate by 90 degrees is referred to as “90-degree defect inspection”.
- the number of true defects detected at 0 degree defect inspection was one and the number of pseudo defects detected was six. It was. In addition, the number of true defects detected in the 90-degree defect inspection was 2, and the number of pseudo defects detected was 1.
- a spatial filter type (inspection light source wavelength 488 nm) defect inspection apparatus (“MAGICS M1350” manufactured by Lasertec Corporation) on the main surface of the mask blank substrate 10 of Example 1 manufactured as described above.
- An area of 132 mm ⁇ 132 mm was inspected for defects.
- the inspection sensitivity condition of this defect inspection apparatus was a sensitivity at which polystyrene latex (PSL) particles having a diameter of 60 nm dispersed on the main surface of the glass substrate could be detected.
- PSL polystyrene latex
- the method for discriminating whether the detected defect is a pseudo defect or a true defect is the same as that in the case of the two-beam interference type defect inspection apparatus.
- the mask blank substrate 10 of Example 1 was measured using a spatial filter type defect inspection apparatus, the number of detected true defects was 6, and the number of detected pseudo defects was 55.
- Example 2 ⁇ Production of Mask Blank Substrate 10>
- a synthetic quartz glass having a size of 152.4 mm ⁇ 152.4 mm and a thickness of 6.35 mm is prepared in the same manner as in Example 1, and a rough polishing process and a precision polishing process are prepared. And an ultra-precision polishing process was performed.
- the conditions of the ultraprecision polishing process are as follows.
- the ultraprecision polishing process for the mask blank substrate 10 of Example 2 was performed as follows. That is, using the above-described double-side polishing apparatus, the ultra-precision polishing step was performed under the following polishing conditions on the ten glass substrates that had finished the precision polishing step. The processing load and polishing time were adjusted as appropriate.
- Polishing liquid Polishing liquid containing water, colloidal silica (average particle diameter D50: 20 nm) and additives (hydroxyethyl cellulose and alkali compound [ammonia]). pH: 10.5. The same polishing pad 17 as in Example 1 was used. After the ultraprecision polishing step, in order to remove polishing abrasive grains (colloidal silica) adhering to the glass substrate, the substrate was washed with a low-concentration silicic acid solution and rinsed with pure water.
- Example 2 ⁇ Power Spectrum Analysis of Mask Blank Substrate 10> Similarly to Example 1, the surface state of the glass substrate of the mask blank substrate 10 of Example 2 was measured with a white interferometer, and power spectrum analysis was performed. A power spectrum analysis was performed by measuring a measurement area of 2.8 mm ⁇ 2.1 mm and a number of pixels of 640 ⁇ 480 using a white interferometer. The result is shown in FIG. Similarly, FIG. 5 shows the result of power spectrum analysis in which a measurement region 693 ⁇ m ⁇ 520 ⁇ m (pixel number 640 ⁇ 480) was measured, and FIG. 5 shows the result of power spectrum analysis in which a measurement region 140 ⁇ m ⁇ 105 ⁇ m (pixel number 640 ⁇ 480) was measured. It is shown in FIG.
- the power spectrum density at a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 2.4 ⁇ 10 7 nm 4 .
- the power spectrum density at a spatial frequency of 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 1.4 ⁇ 10 5 nm 4 . It was lower than 3.0 ⁇ 10 5 nm 4 (FIG. 5).
- the power spectrum density at a spatial frequency of 2.0 ⁇ 10 ⁇ 1 ⁇ m ⁇ 1 is 3.9 ⁇ 10 2 nm 4 .
- Example 2 Similarly to Example 1, using a defect inspection apparatus (“MAGICS M1320” manufactured by Lasertec Co., Ltd.) using a two-beam interference method (inspection light source wavelength 488 nm), for the mask blank of Example 2 manufactured as described above An area of 132 mm ⁇ 132 mm on the main surface of the substrate 10 was inspected for defects. When the mask blank substrate 10 of Example 2 was measured using a two-beam interference type defect inspection apparatus, the number of true defects detected at 0 degree defect inspection was zero and the number of pseudo defects detected was nine. It was. Further, the number of true defects detected in the 90-degree defect inspection was 0, and the number of detected pseudo defects was 16.
- MAGICS M1320 manufactured by Lasertec Co., Ltd.
- a two-beam interference method inspection light source wavelength 488 nm
- Example 2 the mask of Example 2 manufactured as described above using a spatial filter type (inspection light source wavelength 488 nm) defect inspection apparatus (“MAGICS M1350” manufactured by Lasertec Corporation). A defect inspection was performed on a 132 mm ⁇ 132 mm region on the main surface of the blank substrate 10. As a result, when the mask blank substrate 10 of Example 2 was measured using a spatial filter type defect inspection apparatus, the number of detected true defects was 0, and the number of detected pseudo defects was 59.
- MAGICS M1350 inspection light source wavelength 488 nm
- Example 3 ⁇ Production of Mask Blank Substrate 10>
- a synthetic quartz glass having a size of 152.4 mm ⁇ 152.4 mm and a thickness of 6.35 mm is prepared as in Example 1, and a rough polishing process and a precision polishing process are prepared. And an ultra-precision polishing process was performed.
- the conditions of the ultraprecision polishing process are as follows.
- the ultraprecision polishing process for the mask blank substrate 10 of Example 3 was performed as follows. That is, using the above-described double-side polishing apparatus, the ultra-precision polishing step was performed under the following polishing conditions on the ten glass substrates that had finished the precision polishing step. The processing load and polishing time were adjusted as appropriate. Polishing liquid: Polishing liquid containing water, colloidal silica (average particle diameter D50: 23 nm) and additives (hydroxyethylcellulose and alkali compound [ammonia]). pH: 10.5. The same polishing pad 17 as in Example 1 was used. After the ultraprecision polishing step, in order to remove polishing abrasive grains (colloidal silica) adhering to the glass substrate, the substrate was washed with a low-concentration silicic acid solution and rinsed with pure water.
- polishing liquid Polishing liquid containing water, colloidal silica (average particle diameter D50: 23 nm) and additives (hydroxyethylcellulose and alkali compound [
- Example 10 ⁇ Power Spectrum Analysis of Mask Blank Substrate 10> Similarly to Example 1, the surface state of the glass substrate of the mask blank substrate 10 of Example 3 was measured with a white interferometer, and power spectrum analysis was performed. A power spectrum analysis was performed by measuring a measurement area of 2.8 mm ⁇ 2.1 mm and a number of pixels of 640 ⁇ 480 using a white interferometer. The result is shown in FIG. Similarly, FIG. 5 shows the result of power spectrum analysis in which a measurement region 693 ⁇ m ⁇ 520 ⁇ m (pixel number 640 ⁇ 480) was measured, and FIG. 5 shows the result of power spectrum analysis in which a measurement region 140 ⁇ m ⁇ 105 ⁇ m (pixel number 640 ⁇ 480) was measured. It is shown in FIG.
- the power spectrum density at a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 2.3 ⁇ 10 7 nm 4 .
- the power spectrum density at a spatial frequency of 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 1.0 ⁇ 10 5 nm 4 . It was lower than 3.0 ⁇ 10 5 nm 4 (FIG. 5).
- the power spectrum density at a spatial frequency of 2.0 ⁇ 10 ⁇ 1 ⁇ m ⁇ 1 is 3.4 ⁇ 10 2 nm 4 .
- Example 1 As in Example 1, using a defect inspection apparatus (“MAGICS M1320” manufactured by Lasertec Co., Ltd.) using a two-beam interference method (inspection light source wavelength 488 nm), for the mask blank of Example 3 manufactured as described above An area of 132 mm ⁇ 132 mm on the main surface of the substrate 10 was inspected for defects.
- the mask blank substrate 10 of Example 3 was measured using a two-beam interference type defect inspection apparatus, the number of true defects detected at 0 degree defect inspection was 0 and the number of pseudo defects detected was 8. It was. In addition, the number of true defects detected in the 90-degree defect inspection was 0, and the number of detected pseudo defects was 11.
- Example 3 the mask of Example 3 manufactured as described above using a spatial filter type (inspection light source wavelength: 488 nm) defect inspection apparatus ("MAGICS M1350" manufactured by Lasertec Corporation). A defect inspection was performed on a 132 mm ⁇ 132 mm region on the main surface of the blank substrate 10. As a result, when the mask blank substrate 10 of Example 3 was measured using a spatial filter type defect inspection apparatus, the number of detected true defects was 5, and the number of detected pseudo defects was 53.
- MAGICS M1350 inspection light source wavelength: 488 nm
- Example 4 ⁇ Production of Mask Blank Substrate 10> As the mask blank substrate 10 of Example 4, as in Example 1, a synthetic quartz glass having a size of 152.4 mm ⁇ 152.4 mm and a thickness of 6.35 mm is prepared, and a rough polishing process and a precision polishing process are prepared. And an ultra-precision polishing process was performed. However, in the mask blank substrate 10 of Example 4, the conditions of the ultra-precision polishing process are as follows.
- the ultraprecision polishing process for the mask blank substrate 10 of Example 4 was performed as follows. That is, using the above-described double-side polishing apparatus, the ultra-precision polishing step was performed under the following polishing conditions on the ten glass substrates that had finished the precision polishing step. The processing load and polishing time were adjusted as appropriate.
- Polishing liquid Polishing liquid containing water, colloidal silica (average particle diameter D50: 80 nm) and additives (hydroxyethyl cellulose and alkali compound [ammonia]). pH: 10.5. The same polishing pad 17 as in Example 1 was used. After the ultraprecision polishing step, in order to remove polishing abrasive grains (colloidal silica) adhering to the glass substrate, the substrate was washed with a low-concentration silicic acid solution and rinsed with pure water.
- Example 10 ⁇ Power Spectrum Analysis of Mask Blank Substrate 10> Similarly to Example 1, the surface state of the glass substrate of the mask blank substrate 10 of Example 4 was measured with a white interferometer, and power spectrum analysis was performed. A power spectrum analysis was performed by measuring a measurement area of 2.8 mm ⁇ 2.1 mm and a number of pixels of 640 ⁇ 480 using a white interferometer. The result is shown in FIG. Similarly, FIG. 5 shows the result of power spectrum analysis in which a measurement region 693 ⁇ m ⁇ 520 ⁇ m (pixel number 640 ⁇ 480) was measured, and FIG. 5 shows the result of power spectrum analysis in which a measurement region 140 ⁇ m ⁇ 105 ⁇ m (pixel number 640 ⁇ 480) was measured. It is shown in FIG.
- the power spectrum density at a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 4.6 ⁇ 10 7 nm 4 .
- the power spectrum density at a spatial frequency of 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 2.0 ⁇ 10 5 nm 4 . It was lower than 3.0 ⁇ 10 5 nm 4 (FIG. 5).
- the power spectrum density at a spatial frequency of 2.0 ⁇ 10 ⁇ 1 ⁇ m ⁇ 1 is 7.2 ⁇ 10 2 nm 4 .
- Example 4 ⁇ Defect inspection> Similarly to Example 1, for a mask blank of Example 4 manufactured as described above using a defect inspection apparatus (“MAGICS M1320” manufactured by Lasertec Corporation) of a two-beam interference method (inspection light source wavelength 488 nm) An area of 132 mm ⁇ 132 mm on the main surface of the substrate 10 was inspected for defects.
- MAGICS M1320 manufactured by Lasertec Corporation
- the number of true defects detected at 0 degree defect inspection was 0 and the number of pseudo defects detected was 27. It was. Further, the number of true defects detected in the 90-degree defect inspection was 1, and the number of detected pseudo defects was 34.
- Example 4 the mask of Example 4 manufactured as described above using a defect inspection apparatus (“MAGICS M1350” manufactured by Lasertec Co., Ltd.) of the spatial filter method (inspection light source wavelength 488 nm).
- a defect inspection was performed on a 132 mm ⁇ 132 mm region on the main surface of the blank substrate 10.
- the mask blank substrate 10 of Example 4 was measured using a spatial filter type defect inspection apparatus, the number of detected true defects was 1, and the number of detected pseudo defects was 114.
- the ultraprecision polishing process for the mask blank substrate 10 of Comparative Example 1 was performed as follows. That is, using the above-described double-side polishing apparatus, the ultra-precision polishing step was performed under the following polishing conditions on the ten glass substrates that had finished the precision polishing step. The processing load and polishing time were adjusted as appropriate. Polishing liquid: Polishing liquid containing water and colloidal silica (average particle diameter D50: 110 nm). pH: 10.5. The same polishing pad 17 as in Example 1 was used. After the ultraprecision polishing step, in order to remove polishing abrasive grains (colloidal silica) adhering to the glass substrate, the substrate was washed with a low-concentration silicic acid solution and rinsed with pure water.
- FIG. 5 shows the result of power spectrum analysis in which a measurement region 693 ⁇ m ⁇ 520 ⁇ m (pixel number 640 ⁇ 480) was measured, and FIG. 5 shows the result of power spectrum analysis in which a measurement region 140 ⁇ m ⁇ 105 ⁇ m (pixel number 640 ⁇ 480) was measured. It is shown in FIG.
- the power spectrum density at a spatial frequency of 1.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 1.4 ⁇ 10 8 nm 4 . Higher than 6.0 ⁇ 10 7 nm 4 .
- the power spectrum density at a spatial frequency of 5.0 ⁇ 10 ⁇ 2 ⁇ m ⁇ 1 is 8.1 ⁇ 10 5 nm 4 . Higher than 3.0 ⁇ 10 5 nm 4 .
- the power spectrum density at a spatial frequency of 2.0 ⁇ 10 ⁇ 1 ⁇ m ⁇ 1 is 1.6 ⁇ 10 3 nm 4 . Higher than 8.0 ⁇ 10 2 nm 4 .
- ⁇ Defect inspection> Similar to Example 1, using a defect inspection apparatus (“MAGICS M1320” manufactured by Lasertec Co., Ltd.) using a two-beam interference method (inspection light source wavelength 488 nm), for the mask blank of Comparative Example 1 manufactured as described above An area of 132 mm ⁇ 132 mm on the main surface of the substrate 10 was inspected for defects.
- the mask blank substrate 10 of Comparative Example 1 was measured using a two-beam interference type defect inspection apparatus, the number of true defects detected at 0 degree defect inspection was 2, and the number of pseudo defects detected was 1317. It was. In addition, the number of true defects detected in the 90-degree defect inspection was 2, and the number of pseudo defects detected was 1067.
- Example 2 similarly to Example 1, the mask of Comparative Example 1 manufactured as described above using a spatial filter type (inspection light source wavelength 488 nm) defect inspection apparatus (“MAGICS M1350” manufactured by Lasertec Corporation). A defect inspection was performed on a 132 mm ⁇ 132 mm region on the main surface of the blank substrate 10. As a result, when the mask blank substrate 10 of Comparative Example 1 was measured using a spatial filter type defect inspection apparatus, the number of detected true defects was 5, and the number of detected pseudo defects was 300.
- MAGICS M1350 inspection light source wavelength 488 nm defect inspection apparatus
- the number of detected pseudo defects is 1317 in the mask blank substrate 10 of Comparative Example 1 that does not have a predetermined spatial frequency by power spectrum analysis. (0 degree) and 1067 pieces (90 degrees), which were many orders of magnitude greater than those of the mask blank substrate 10 of Examples 1 to 4.
- the maximum number of detected pseudo defects is 34 (Example 4, 90 degrees). It was. Therefore, it has been clarified that in the case of the mask blank substrate 10 having a predetermined spatial frequency by power spectrum analysis, it is possible to suppress a significant difference in the number of detected pseudo defects between the substrates.
- the number of detected pseudo defects in Comparative Example 1 was a difference of about 6 times at maximum compared to Examples 1 to 4. Therefore, in the case of using the two-beam interference type defect inspection apparatus, the difference in the number of detected pseudo defects in Examples 1 to 4 and Comparative Example 1 is different from the case of using the two-beam interference type defect inspection apparatus. It was found to be relatively small compared.
- a light shielding film 51 was formed on the main surface (one main surface) of the mask blank substrate 10 of Examples 1 to 4 and Comparative Example 1.
- Mo molybdenum
- Si silicon
- the power of the DC power source is 1.9 kW
- reactive sputtering DC sputtering
- DC sputtering reactive sputtering
- the light shielding film 51 for ArF excimer laser (wavelength: 193 nm) having the laminated structure of the lower layer made of MoSiN and the upper layer made of MoSiN is formed on the mask blank substrate 10 of Examples 1 to 4 and Comparative Example 1.
- the thin film-coated substrates of Examples 1 to 4 and Comparative Example 1 were obtained.
- the light shielding film 51 had an optical density of 3.0 or more with respect to the exposure light of the ArF excimer laser.
- an etching mask film 52 (CrN film having a film thickness of 5 nm) made of a chromium-based material is formed. Then, the mask blank 50 in which the light shielding film 51 and the etching mask film 52 were laminated on the main surface of the glass substrate was manufactured. Thus, the mask blanks 50 of Examples 1 to 4 and Comparative Example 1 were obtained.
- a resist film was formed on the etching mask film 52 of the mask blank 50 of Examples 1 to 4 and Comparative Example 1 by a spin coating method. Next, a predetermined mask pattern was drawn and exposed on the resist film, and development processing was performed to form a resist pattern. Using this resist pattern as a mask, dry etching using a mixed gas of Cl 2 and O 2 as an etching gas was performed to form a predetermined pattern on the etching mask film 52.
- the resist film is peeled off, and the etching mask film 52 on which a predetermined mask pattern is formed is used as a mask, dry etching using a mixed gas of SF 6 and He is performed as an etching gas, and the light shielding film 51 is subjected to a predetermined mask. A pattern was formed. Further, dry etching using a mixed gas of Cl 2 and O 2 as an etching gas was performed, and the etching mask film 52 was removed. Through these steps, the transfer masks 60 of Examples 1 to 4 and Comparative Example 1 having the light shielding film 51 having a predetermined mask pattern formed on the main surface of the glass substrate were produced.
- Mask blank substrate (substrate) 12 sun gear 13 internal gear 14 carrier 15 upper surface plate 16 lower surface plate 17 polishing pad 17A base material 17B nap layer 18 pore 50 mask blank (transmission type mask blank) 51 light shielding film 51a light shielding film pattern 52 etching mask film 60 transfer mask (transmission type mask)
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Abstract
Description
本発明の構成1は、2つの主表面を有する基板からなるマスクブランク用基板であって、前記マスクブランク用基板の転写パターンが形成される側の前記主表面は、転写パターン形成領域内の前記主表面の表面形状を、白色干渉計を用いて2.8mm×2.1mmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数1.0×10-2μm-1のパワースペクトル密度が、6.0×107nm4以下となる表面形状を有することを特徴とするマスクブランク用基板である。
本発明の構成2は、前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、前記白色干渉計を用いて693μm×520μmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数5.0×10-2μm-1のパワースペクトル密度が、3.0×105nm4以下となる表面形状を有することを特徴とする構成1記載のマスクブランク用基板である。
本発明の構成3は、前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、前記白色干渉計を用いて140μm×105μmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数2.0×10-1μm-1のパワースペクトル密度が、8.0×102nm4以下となる表面形状を有することを特徴とする構成1又は2に記載のマスクブランク用基板である。
本発明の構成4は、前記転写パターンが形成される側とは異なる側の前記主表面は、前記転写パターン形成領域と同じ大きさの領域内の前記主表面に対し、前記白色干渉計を用いて2.8mm×2.1mmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数1.0×10-2μm-1のパワースペクトル密度が、6.0×107nm4以下となる表面形状を有することを特徴とする構成1から3のいずれかに記載のマスクブランク用基板である。
本発明の構成5は、上述の構成1から4のいずれかに記載のマスクブランク用基板の前記転写パターンが形成される側の前記主表面に、前記転写パターン形成用の薄膜が設けられていることを特徴とするマスクブランクである。
本発明の構成6は、上述の構成5に記載のマスクブランクの前記薄膜に前記転写パターンが設けられていることを特徴とする転写用マスクである。
本発明の構成7は、2つの主表面を有する基板からなるマスクブランク用基板の製造方法であって、前記マスクブランク用基板の転写パターンが形成される側であり、かつ転写パターン形成領域内の前記主表面に対し、2光束干渉を用いる方式により欠陥検査を行う欠陥検査工程を備え、前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、白色干渉計を用いて2.8mm×2.1mmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数1.0×10-2μm-1のパワースペクトル密度が、6.0×107nm4以下となる表面形状を有することを特徴とするマスクブランク用基板の製造方法である。
本発明の構成8は、前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、前記白色干渉計を用いて693μm×520μmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数5.0×10-2μm-1のパワースペクトル密度が、3.0×105nm4以下となる表面形状を有することを特徴とする構成7記載のマスクブランク用基板の製造方法である。
本発明の構成9は、前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、前記白色干渉計を用いて140μm×105μmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数2.0×10-1μm-1のパワースペクトル密度が、8.0×102nm4以下となる表面形状を有することを特徴とする構成7又は8に記載のマスクブランク用基板の製造方法である。
本発明の構成10は、前記欠陥検査工程の前に、研磨定盤の研磨パッド上を、研磨液を供給しつつ、前記基板を相対移動させることにより、前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面を研磨する研磨工程を備えることを特徴とする構成7から9のいずれかに記載のマスクブランク用基板の製造方法である。
本発明の構成11は、前記研磨液は、平均粒子径D50が100nm以下であるコロイダルシリカを含むことを特徴とする構成10記載のマスクブランク用基板の製造方法である。
本発明の構成12は、構成7から11のいずれかに記載のマスクブランク用基板の製造方法で製造された前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面に、パターン形成用の薄膜を設ける工程を備えていることを特徴とするマスクブランクの製造方法である。
本発明の構成13は、構成12記載のマスクブランクの製造方法で製造されたマスクブランクの前記薄膜に前記転写パターンを形成する工程を備えることを特徴とする転写用マスクの製造方法である。
まず、本発明の一実施形態に係るマスクブランク用基板10について以下に説明する。
マスクブランク用基板10の表面を、例えば白色干渉計や、原子間力顕微鏡で測定して得られた前記基板主表面の凹凸をフーリエ変換することにより、前記凹凸を所定の空間周波数での振幅強度で表すことができる。これは、前記凹凸(つまり基板主表面の微細形状)の測定データを、所定の空間周波数の波の和として表す、つまり基板の表面形状を所定の空間周波数の波に分けていくものである。
マスクブランク用基板10における代表的な表面粗さの指標であるRms(Root means square))は、二乗平均平方根粗さであり、平均線から測定曲線までの偏差の二乗を平均した値の平方根である。すなわちRmsは下式(1)で表される。
また、本実施形態のマスクブランク用基板10は、転写パターンが形成される側の主表面は、少なくともパターン転写精度、位置精度を得る観点から高平坦度となるように表面加工されていることが好ましい。ArFエキシマレーザー露光用の透過型マスクブランクに使用するマスクブランク用基板10の場合、基板の転写パターンが形成される側の主表面における132mm×132mmの四角形の内側領域、又は142mm×142mmの四角形の内側領域においては、平坦度が0.3μm以下であることが好ましく、特に好ましくは、0.2μm以下である。また、転写パターンが形成される側と反対側の主表面も、同程度の平坦であることが必要である。
以上説明した本発明のマスクブランク用基板10は、次のようにして製造することができる。
図7に示すとおり、研磨処理に用いられる研磨パッド17は、不織布や、PET樹脂等の樹脂フィルムなどからなる基材17Aと、この基材17A上に形成され、表面に開孔を有する発泡した樹脂からなるナップ層17Bとを有してなるものである。図示していないが、基材17Aとナップ層17Bとの間に緩衝層を備えることができる。緩衝層は、研磨パッド17全体で圧縮変形量を調整するために設けられるものであり、好ましくは発泡した樹脂である。
(1)樹脂溶液を薄く引き延ばし熱風乾燥し、50μm程度の厚みの乾式フィルムを作製する。
(2)フィルム作製後しばらく養生する。
(3)測定部の長さ20mm、幅5mm、厚さ0.05mmの短冊状試料を、引っ張り速度300mm/分で引っ張る。
(4)100%伸長特(2倍延伸時)の張力を試料の初期断面積で割り、100%モジュラス(MPa表示)を求める。
(5)試料数n=7の平均値を求める。
本発明は、上述のマスクブランク用基板10の転写パターンが形成される側の主表面に、転写パターン形成用の薄膜が設けられていることを特徴とするマスクブランク50である。本発明のマスクブランク50によれば、所定の表面形状の主表面を有する上述のマスクブランク用基板10を用いることによって、2光束干渉方式の欠陥検査装置を使用して、マスクブランク50の転写パターン形成用の薄膜の欠陥検査をする際の疑似欠陥の検出を抑制することができ、これによりマスクブランク50に存在する致命欠陥の顕在化を図ることができる。
(1)遷移金属を含む材料からなる遮光膜51を備えたバイナリ型マスクブランク50
かかるバイナリ型マスクブランク50は、基板主表面上に遮光膜51(薄膜)を有する形態のものであり、この遮光膜51は、クロム、タンタル、ルテニウム、タングステン、チタン、ハフニウム、モリブデン、ニッケル、バナジウム、ジルコニウム、ニオブ、パラジウム、ロジウム、スズ、インジウム等の遷移金属単体あるいはその化合物を含む材料からなる。例えば、タンタルに、酸素、窒素、ホウ素などの元素から選ばれる1種以上の元素を添加したタンタル化合物で構成した遮光膜51が挙げられる。
かかるバイナリ型マスクブランク50は、遮光膜51を、遮光層と表面反射防止層との2層構造や、さらに遮光層と基板との間に裏面反射防止層を加えた3層構造としたものなどがある。
また、遮光膜51の膜厚方向における組成が連続的又は段階的に異なる組成傾斜膜としてもよい。
かかる位相シフトマスクブランクとしては、基板主表面上に光半透過膜(薄膜)を有する形態のハーフトーン型位相シフトマスクブランクが挙げられる。このハーフトーン型位相シフトマスクブランクの光半透過膜をパターニングしてシフタ部を設けることによって、ハーフトーン型位相シフトマスクが作製される。かかる位相シフトマスクにおいては、光半透過膜を透過した光に基づき転写領域に形成される光半透過膜パターンによる被転写基板のパターン不良を防止するために、基板主表面上に光半透過膜とその上の遮光膜(遮光帯)とを有する形態とするものが挙げられる。また、ハーフトーン型位相シフトマスクブランクのほかに、基板をエッチング等により掘り込んでシフタ部を設ける基板掘り込みタイプであるレベンソン型位相シフトマスク用やエンハンサー型位相シフトマスク用のマスクブランクが挙げられる。
この遮光膜51(薄膜)は、遷移金属及びケイ素の化合物を含む材料からなる。あるいは、この遮光膜51(薄膜)は、遷移金属及びケイ素と、酸素及び/又は窒素を主たる構成要素とする材料からなる。あるいは、この遮光膜51は、遷移金属と、酸素、窒素及び/又はホウ素を主たる構成要素とする材料からなる。遷移金属には、モリブデン、タンタル、タングステン、チタン、ハフニウム、ニッケル、バナジウム、ジルコニウム、ニオブ、パラジウム、ルテニウム、ロジウム、クロム等が適用可能である。
特に、遮光膜51をモリブデンシリサイドの化合物で形成する場合であって、遮光層(MoSiN等)と表面反射防止層(MoSiN等)との2層構造や、さらに遮光層と基板との間に裏面反射防止層(MoSiON等)を加えた3層構造がある。
また、遮光膜51の膜厚方向における組成が連続的又は段階的に異なる組成傾斜膜としてもよい。
本発明は、マスクブランク50の前記薄膜に転写パターンが設けられていることを特徴とする転写用マスク60である。図3は、本発明の転写用マスク60の構成の一例の断面模式図である。本発明の転写用マスク60は、本発明のマスクブランク50の製造方法によって製造されたマスクブランク50の薄膜に転写パターンを形成することによって、製造することができる。図3の例では、マスクブランク用基板10の主表面上に遮光膜パターン51a(転写パターン)が形成されている。薄膜への転写パターンの形成は、公知の方法を用いて行うことが可能である。
上述の転写用マスク60及び所定の露光装置を使用したリソグラフィープロセスにより、半導体基板等の被転写体上に形成されたレジスト膜に、転写用マスク60の転写パターンに基づく回路パターン等の転写パターンを転写し、その他種々の工程を経ることで、半導体基板上に配線など種々のパターン等が形成された半導体デバイスを製造することができる。
<マスクブランク用基板10の作製>
実施例1のマスクブランク用基板10として、大きさが152.4mm×152.4mm、厚さが6.35mmの合成石英ガラスを準備し、次のように粗研磨工程、精密研磨工程及び超精密研磨工程を実施した。
端面を面取り加工し、両面ラッピング装置によって研削加工を終えた合成石英ガラス基板を、両面研磨装置に10枚セットし、以下の研磨条件で粗研磨工程を行った。なお、加工荷重、研磨時間は適宜調整して行った。
研磨液:酸化セリウム(平均粒子径2~3μm)+水
研磨パッド:硬質ポリシャ(ウレタンパッド)
上記粗研磨工程後、ガラス基板に付着した研磨砥粒を除去するため、ガラス基板を洗浄槽に浸漬(超音波印加)し、洗浄を行った。
上述の両面研磨装置を使用し、粗研磨工程を終えた上記10枚のガラス基板に対し、以下の研磨条件で精密研磨工程を行った。なお、加工荷重、研磨時間は適宜調整して行った。
研磨液:酸化セリウム(平均粒子径1μm)+水
研磨パッド:軟質ポリシャ(ウレタンパッド)
上記精密研磨工程後、ガラス基板に付着した研磨砥粒を除去するため、ガラス基板を洗浄槽に浸漬(超音波印加)し、洗浄を行った。
上述の両面研磨装置を使用し、精密研磨工程を終えた上記10枚のガラス基板に対し、以下の研磨条件で超精密研磨工程を行った。なお、加工荷重、研磨時間は適宜調整して行った。
研磨液:水、コロイダルシリカ(平均粒子径D50:18nm)及び添加剤(ヒドロキシエチルセルロース及びアルカリ化合物[アンモニア])を含む研磨液。pH:10.5。
研磨パッド17:パッド構造がPET(基材17A)/ナップ層17B、圧縮変形量274μm、ナップ層17Bの100%モジュラスが3.0MPaである研磨パッド17を使用。
なお、研磨パッド17の基材17Aは、PET樹脂フィルムとし、ナップ層17Bはポリウレタン樹脂からなる。また、研磨パッド17の圧縮変形量、ナップ層17Bの100%モジュラスは前述の方法により測定した。上記超精密研磨工程後、ガラス基板に付着した研磨砥粒(コロイダルシリカ)を除去するため、低濃度のケイフッ酸水溶液で洗浄後、純水によるリンスを行った。
実施例1のマスクブランク用基板10の表面状態を、Zygo社製の白色干渉計である非接触表面形状測定機NewView7300にて測定し、パワースペクトル解析を行った。白色干渉計により、測定領域2.8mm×2.1mm、ピクセル数640×480を測定したパワースペクトル解析を行った。その結果を図4に示す。同様に、測定領域693μm×520μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図5に、測定領域140μm×105μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図6に示す。なお、図4~6において、空間周波数の値を示す太線は、左から空間周波数1.0×10-2μm-1、5.0×10-2μm-1及び2.0×10-1μm-1を示す。
2光束干渉方式(検査光源波長488nm)の欠陥検査装置(レーザーテック社製「MAGICS M1320」)を使用して、上述のようにして製造された実施例1のマスクブランク用基板10主表面における132mm×132mmの領域を欠陥検査した。この欠陥検査装置の検査感度条件は、ガラス基板の主表面上に散布した直径150nmのポリスチレンラテックス(PSL)粒子が検出できる感度とした。なお、PSL粒子は、その粒子同士が1mm以内で近接しあう確率が1%以下となるような特性を有するものである。さらに、この2光束干渉方式の欠陥検査装置を使用して、基板を90度回転させて、上述のようにして製造されたマスクブランク用基板10主表面における132mm×132mmの領域を欠陥検査した。最初の欠陥検査を「0度の欠陥検査」、基板を90度回転させての欠陥検査を「90度の欠陥検査」という。0度の欠陥検査結果と90度の欠陥検査結果とを比較することにより、疑似欠陥又は真欠陥であるかを判別した。
<マスクブランク用基板10の作製>
実施例2のマスクブランク用基板10として、実施例1と同様に、大きさが152.4mm×152.4mm、厚さが6.35mmの合成石英ガラスを準備し、粗研磨工程、精密研磨工程及び超精密研磨工程を実施した。ただし、実施例2のマスクブランク用基板10において、超精密研磨工程の条件は、次のとおりである。
研磨液:水、コロイダルシリカ(平均粒子径D50:20nm)及び添加剤(ヒドロキシエチルセルロース及びアルカリ化合物[アンモニア])を含む研磨液。pH:10.5。
研磨パッド17は実施例1と同じものを使用した。上記超精密研磨工程後、ガラス基板に付着した研磨砥粒(コロイダルシリカ)を除去するため、低濃度のケイフッ酸水溶液で洗浄後、純水によるリンスを行った。
実施例1と同様に、実施例2のマスクブランク用基板10のガラス基板の表面状態を白色干渉計にて測定し、パワースペクトル解析を行った。白色干渉計により、測定領域2.8mm×2.1mm、ピクセル数640×480を測定したパワースペクトル解析を行った。その結果を図4に示す。同様に、測定領域693μm×520μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図5に、測定領域140μm×105μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図6に示す。
実施例1と同様に、2光束干渉方式(検査光源波長488nm)の欠陥検査装置(レーザーテック社製「MAGICS M1320」)を使用して、上述のようにして製造された実施例2のマスクブランク用基板10主表面における132mm×132mmの領域を欠陥検査した。実施例2のマスクブランク用基板10を2光束干渉方式の欠陥検査装置を使用して測定したときに、0度の欠陥検査の真欠陥検出個数は0個、疑似欠陥検出個数は9個であった。また、90度の欠陥検査の真欠陥検出個数は0個、疑似欠陥検出個数は16個であった。
<マスクブランク用基板10の作製>
実施例3のマスクブランク用基板10として、実施例1と同様に、大きさが152.4mm×152.4mm、厚さが6.35mmの合成石英ガラスを準備し、粗研磨工程、精密研磨工程及び超精密研磨工程を実施した。ただし、実施例3のマスクブランク用基板10において、超精密研磨工程の条件は、次のとおりである。
研磨液:水、コロイダルシリカ(平均粒子径D50:23nm)及び添加剤(ヒドロキシエチルセルロース及びアルカリ化合物[アンモニア])を含む研磨液。pH:10.5。
研磨パッド17は実施例1と同じものを使用した。上記超精密研磨工程後、ガラス基板に付着した研磨砥粒(コロイダルシリカ)を除去するため、低濃度のケイフッ酸水溶液で洗浄後、純水によるリンスを行った。
実施例1と同様に、実施例3のマスクブランク用基板10のガラス基板の表面状態を白色干渉計にて測定し、パワースペクトル解析を行った。白色干渉計により、測定領域2.8mm×2.1mm、ピクセル数640×480を測定したパワースペクトル解析を行った。その結果を図4に示す。同様に、測定領域693μm×520μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図5に、測定領域140μm×105μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図6に示す。
実施例1と同様に、2光束干渉方式(検査光源波長488nm)の欠陥検査装置(レーザーテック社製「MAGICS M1320」)を使用して、上述のようにして製造された実施例3のマスクブランク用基板10主表面における132mm×132mmの領域を欠陥検査した。実施例3のマスクブランク用基板10を2光束干渉方式の欠陥検査装置を使用して測定したときに、0度の欠陥検査の真欠陥検出個数は0個、疑似欠陥検出個数は8個であった。また、90度の欠陥検査の真欠陥検出個数は0個、疑似欠陥検出個数は11個であった。
<マスクブランク用基板10の作製>
実施例4のマスクブランク用基板10として、実施例1と同様に、大きさが152.4mm×152.4mm、厚さが6.35mmの合成石英ガラスを準備し、粗研磨工程、精密研磨工程及び超精密研磨工程を実施した。ただし、実施例4のマスクブランク用基板10において、超精密研磨工程の条件は、次のとおりである。
研磨液:水、コロイダルシリカ(平均粒子径D50:80nm)及び添加剤(ヒドロキシエチルセルロース及びアルカリ化合物[アンモニア])を含む研磨液。pH:10.5。
研磨パッド17は実施例1と同じものを使用した。上記超精密研磨工程後、ガラス基板に付着した研磨砥粒(コロイダルシリカ)を除去するため、低濃度のケイフッ酸水溶液で洗浄後、純水によるリンスを行った。
実施例1と同様に、実施例4のマスクブランク用基板10のガラス基板の表面状態を白色干渉計にて測定し、パワースペクトル解析を行った。白色干渉計により、測定領域2.8mm×2.1mm、ピクセル数640×480を測定したパワースペクトル解析を行った。その結果を図4に示す。同様に、測定領域693μm×520μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図5に、測定領域140μm×105μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図6に示す。
実施例1と同様に、2光束干渉方式(検査光源波長488nm)の欠陥検査装置(レーザーテック社製「MAGICS M1320」)を使用して、上述のようにして製造された実施例4のマスクブランク用基板10主表面における132mm×132mmの領域を欠陥検査した。実施例4のマスクブランク用基板10を2光束干渉方式の欠陥検査装置を使用して測定したときに、0度の欠陥検査の真欠陥検出個数は0個、疑似欠陥検出個数は27個であった。また、90度の欠陥検査の真欠陥検出個数は1個、疑似欠陥検出個数は34個であった。
<マスクブランク用基板10の作製>
比較例1のマスクブランク用基板10として、実施例1と同様に、大きさが152.4mm×152.4mm、厚さが6.35mmの合成石英ガラスを準備し、粗研磨工程、精密研磨工程及び超精密研磨工程を実施した。ただし、比較例1のマスクブランク用基板10において、超精密研磨工程の条件は、次のとおりである。
研磨液:水、コロイダルシリカ(平均粒子径D50:110nm)を含む研磨液。pH:10.5。
研磨パッド17は実施例1と同じものを使用した。上記超精密研磨工程後、ガラス基板に付着した研磨砥粒(コロイダルシリカ)を除去するため、低濃度のケイフッ酸水溶液で洗浄後、純水によるリンスを行った。
実施例1と同様に、比較例1のマスクブランク用基板10のガラス基板の表面状態を白色干渉計にて測定し、パワースペクトル解析を行った。白色干渉計により、測定領域2.8mm×2.1mm、ピクセル数640×480を測定したパワースペクトル解析を行った。その結果を図4に示す。同様に、測定領域693μm×520μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図5に、測定領域140μm×105μm(ピクセル数640×480)を測定したパワースペクトル解析の結果を図6に示す。
実施例1と同様に、2光束干渉方式(検査光源波長488nm)の欠陥検査装置(レーザーテック社製「MAGICS M1320」)を使用して、上述のようにして製造された比較例1のマスクブランク用基板10主表面における132mm×132mmの領域を欠陥検査した。比較例1のマスクブランク用基板10を2光束干渉方式の欠陥検査装置を使用して測定したときに、0度の欠陥検査の真欠陥検出個数は2個、疑似欠陥検出個数は1317個であった。また、90度の欠陥検査の真欠陥検出個数は2個、疑似欠陥検出個数は1067個であった。
上述のようにして製造した実施例1~4及び比較例1のマスクブランク用基板10の薄膜が形成される側の主表面(一方の主表面)の表面形状を、表面形状解析装置(UltraFLAT 200M(Corning TROPEL社製))を用いて測定した(測定領域は、マスクブランク用基板10の中心を基準とした一辺が142mmの四角形の内側領域。以降、表面形状解析装置で測定している表面形状の測定領域は同じ。)。いずれのマスクブランク用基板10も、薄膜が形成される側の主表面(一方の主表面)の142mm四方の内側領域における平坦度は、0.2μm以下であり、表面形状は凸形状であった。
実施例1~4及び比較例1のマスクブランク50のエッチングマスク膜52上にレジスト膜をスピン塗布法によって形成した。次に、レジスト膜に所定のマスクパターンを描画露光し、現像処理等を行い、レジストパターンを形成した。このレジストパターンをマスクとし、エッチングガスにCl2及びO2の混合ガスを用いたドライエッチングを行い、エッチングマスク膜52に所定のパターンを形成した。
次に、上述の実施例1~4及び比較例1の転写用マスク60に対し、それぞれAIMS193(Carl Zeiss社製)を用いて、波長193nmの露光光で半導体デバイス上のレジスト膜に露光転写したときにおける転写像のシミュレーションを行った。実施例1~4の各転写用マスク60に対するシミュレーションの露光転写像を検証したところ、設計仕様を十分に満たしていることがわかった。これらの結果から、実施例1~4の各転写用マスク60を露光装置のマスクステージにセットし、半導体デバイス上のレジスト膜に露光転写したとしても、最終的に半導体デバイス上に形成される回路パターンは高精度で形成できるといえる。
以上、本発明の好ましい実施形態について説明したが、本発明は、上記の実施形態に限定されることなく、本発明の主旨を逸脱しない範囲で種々の変更が可能であり、それらも本発明の範囲内に包含されるものであることはいうまでもない。
本出願は、2014年3月26日に出願された、日本国特許出願第2014-63308号からの優先権を基礎として、その利益を主張するものであり、その開示はここに全体として参考文献として取り込む。
12 太陽歯車
13 内歯歯車
14 キャリア
15 上定盤
16 下定盤
17 研磨パッド
17A 基材
17B ナップ層
18 ポア
50 マスクブランク(透過型マスクブランク)
51 遮光膜
51a 遮光膜パターン
52 エッチングマスク膜
60 転写用マスク(透過型マスク)
Claims (13)
- 2つの主表面を有する基板からなるマスクブランク用基板であって、
前記マスクブランク用基板の転写パターンが形成される側の前記主表面は、転写パターン形成領域内の前記主表面の表面形状を、白色干渉計を用いて2.8mm×2.1mmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数1.0×10-2μm-1のパワースペクトル密度が、6.0×107nm4以下となる表面形状を有することを特徴とするマスクブランク用基板。 - 前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、前記白色干渉計を用いて693μm×520μmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数5.0×10-2μm-1のパワースペクトル密度が、3.0×105nm4以下となる表面形状を有することを特徴とする請求項1記載のマスクブランク用基板。
- 前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、前記白色干渉計を用いて140μm×105μmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数2.0×10-1μm-1のパワースペクトル密度が、8.0×102nm4以下となる表面形状を有することを特徴とする請求項1又は2に記載のマスクブランク用基板。
- 前記転写パターンが形成される側とは異なる側の前記主表面は、前記転写パターン形成領域と同じ大きさの領域内の前記主表面に対し、前記白色干渉計を用いて2.8mm×2.1mmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数1.0×10-2μm-1のパワースペクトル密度が、6.0×107nm4以下となる表面形状を有することを特徴とする請求項1から3のいずれかに記載のマスクブランク用基板。
- 請求項1から4のいずれかに記載のマスクブランク用基板の前記転写パターンが形成される側の前記主表面に、前記転写パターン形成用の薄膜が設けられていることを特徴とするマスクブランク。
- 請求項5に記載のマスクブランクの前記薄膜に前記転写パターンが設けられていることを特徴とする転写用マスク。
- 2つの主表面を有する基板からなるマスクブランク用基板の製造方法であって、
前記マスクブランク用基板の転写パターンが形成される側であり、かつ転写パターン形成領域内の前記主表面に対し、2光束干渉を用いる方式により欠陥検査を行う欠陥検査工程を備え、
前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、白色干渉計を用いて2.8mm×2.1mmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数1.0×10-2μm-1のパワースペクトル密度が、6.0×107nm4以下となる表面形状を有することを特徴とするマスクブランク用基板の製造方法。 - 前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、前記白色干渉計を用いて693μm×520μmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数5.0×10-2μm-1のパワースペクトル密度が、3.0×105nm4以下となる表面形状を有することを特徴とする請求項7記載のマスクブランク用基板の製造方法。
- 前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面は、前記転写パターン形成領域内の前記主表面に対し、前記白色干渉計を用いて140μm×105μmの測定領域を640×480のピクセル数の条件で測定した場合、その測定結果から算出される空間周波数2.0×10-1μm-1のパワースペクトル密度が、8.0×102nm4以下となる表面形状を有することを特徴とする請求項7又は8に記載のマスクブランク用基板の製造方法。
- 前記欠陥検査工程の前に、研磨定盤の研磨パッド上を、研磨液を供給しつつ、前記基板を相対移動させることにより、前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面を研磨する研磨工程を備えることを特徴とする請求項7から9のいずれかに記載のマスクブランク用基板の製造方法。
- 前記研磨液は、平均粒子径D50が100nm以下であるコロイダルシリカを含むことを特徴とする請求項10記載のマスクブランク用基板の製造方法。
- 請求項7から11のいずれかに記載の前記マスクブランク用基板の製造方法で製造された前記マスクブランク用基板の前記転写パターンが形成される側の前記主表面に、パターン形成用の薄膜を設ける工程を備えていることを特徴とするマスクブランクの製造方法。
- 請求項12記載のマスクブランクの製造方法で製造されたマスクブランクの前記薄膜に前記転写パターンを形成する工程を備えることを特徴とする転写用マスクの製造方法。
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US10324370B2 (en) * | 2016-09-06 | 2019-06-18 | Unimicron Technology Corp. | Manufacturing method of circuit substrate and mask structure and manufacturing method thereof |
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US11442021B2 (en) * | 2019-10-11 | 2022-09-13 | Kla Corporation | Broadband light interferometry for focal-map generation in photomask inspection |
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005231994A (ja) * | 2004-02-20 | 2005-09-02 | Schott Ag | 低熱膨張性ガラスセラミック |
WO2006030684A1 (ja) * | 2004-09-13 | 2006-03-23 | Nikon Corporation | 投影光学系、投影光学系の製造方法、露光装置及び露光方法 |
JP2006176341A (ja) * | 2004-12-20 | 2006-07-06 | Hoya Corp | マスクブランクス用ガラス基板の製造方法,マスクブランクスの製造方法,露光用マスクの製造方法,及び,半導体装置の製造方法 |
JP2008094649A (ja) * | 2006-10-10 | 2008-04-24 | Shinetsu Quartz Prod Co Ltd | 石英ガラス基板の表面処理方法及び水素ラジカルエッチング装置 |
JP2013061239A (ja) * | 2011-09-13 | 2013-04-04 | Toshiba Corp | マスク表面粗さ測定方法及び測定装置 |
WO2013146990A1 (ja) * | 2012-03-28 | 2013-10-03 | Hoya株式会社 | マスクブランク用基板、多層反射膜付き基板、透過型マスクブランク、反射型マスクブランク、透過型マスク、反射型マスク及び半導体装置の製造方法 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6440267A (en) | 1987-08-07 | 1989-02-10 | Shinetsu Chemical Co | Manufacture of precisely polished glass |
JP4543141B2 (ja) | 1999-07-13 | 2010-09-15 | レーザーテック株式会社 | 欠陥検査装置 |
JP3210654B1 (ja) | 2001-05-02 | 2001-09-17 | レーザーテック株式会社 | 光学式走査装置及び欠陥検出装置 |
US7199863B2 (en) * | 2004-12-21 | 2007-04-03 | Asml Netherlands B.V. | Method of imaging using lithographic projection apparatus |
JP5111954B2 (ja) * | 2007-06-22 | 2013-01-09 | 新光電気工業株式会社 | 静電チャック及びその製造方法 |
KR102101944B1 (ko) * | 2011-02-28 | 2020-04-21 | 코닝 인코포레이티드 | 낮은 디스플레이 스파클을 갖는 방현 표면을 구비한 유리 |
-
2014
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Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005231994A (ja) * | 2004-02-20 | 2005-09-02 | Schott Ag | 低熱膨張性ガラスセラミック |
WO2006030684A1 (ja) * | 2004-09-13 | 2006-03-23 | Nikon Corporation | 投影光学系、投影光学系の製造方法、露光装置及び露光方法 |
JP2006176341A (ja) * | 2004-12-20 | 2006-07-06 | Hoya Corp | マスクブランクス用ガラス基板の製造方法,マスクブランクスの製造方法,露光用マスクの製造方法,及び,半導体装置の製造方法 |
JP2008094649A (ja) * | 2006-10-10 | 2008-04-24 | Shinetsu Quartz Prod Co Ltd | 石英ガラス基板の表面処理方法及び水素ラジカルエッチング装置 |
JP2013061239A (ja) * | 2011-09-13 | 2013-04-04 | Toshiba Corp | マスク表面粗さ測定方法及び測定装置 |
WO2013146990A1 (ja) * | 2012-03-28 | 2013-10-03 | Hoya株式会社 | マスクブランク用基板、多層反射膜付き基板、透過型マスクブランク、反射型マスクブランク、透過型マスク、反射型マスク及び半導体装置の製造方法 |
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