Manufacturing method for glass components for EUV mask blanks

Abstract

To provide a technique to improve the productivity of a glass substrate.SOLUTION: A glass member for EUV mask blanks includes a first principal face and a second principal face, oriented in a direction opposite to that of the first principal face. For at least a predetermined region of the first principal face, in a roughness curve in a direction where an arithmetic mean roughness Ra is maximum, the arithmetic mean roughness Ra is 1.5 μm or more and 5.0 μm or less.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a glass part for an EUV mask blank. Material manufacturing manufacturing method In the law related to.

Background Art

[0002] In recent years, with the miniaturization of semiconductor devices, extreme ultraviolet (EUV) lithography (EUVL), an exposure technique using extreme ultraviolet rays, has been developed. EUV includes soft X-rays and vacuum ultraviolet rays, and specifically refers to light with a wavelength of about 0.2 nm to 100 nm. At present, EUV with a wavelength of about 13.5 nm is mainly being considered.

[0003] An EUV mask has a glass substrate, a multilayer reflective film that reflects EUV, and an absorption film that absorbs EUV, in this order. An opening pattern is formed in the absorption film. In EUVL, the opening pattern of the absorption film is transferred onto a target substrate such as a semiconductor substrate. Transferring includes reducing and transferring.

[0004] A method for manufacturing a glass substrate for an EUV mask blank includes obtaining a glass member by slicing a glass block with a wire saw, and obtaining a glass substrate by grinding the glass member.

[0005] Patent Document 1 describes obtaining a glass plate by slicing a glass block with a wire saw, and that it is desirable that the surface roughness of the glass plate immediately after slicing is low. Patent Document 2 describes that the surface roughness of a glass plate for a magnetic disk immediately after slicing is 0.3 μm.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

[0007] A method for manufacturing a glass substrate for an EUV mask blank comprises obtaining a glass component by slicing a glass block with a wire saw, and obtaining a glass substrate by grinding the glass component.

[0008] Grinding of glass components is performed using a grinding pad in which abrasive grains are fixed. If the abrasive grains become dull (wear down) or clogged (grinding debris gets stuck in the pockets between the abrasive grains), the grinding rate will decrease.

[0009] Therefore, the grinding pads are periodically dressed. Dressing involves removing worn-out abrasive grains to expose new ones, or removing grinding debris that has accumulated in the pockets between the abrasive grains. This restores the grinding rate.

[0010] Dressing the grinding pads requires interrupting the production of glass substrates, which reduces the productivity of glass substrate production.

[0011] One aspect of this disclosure provides a technology for improving the productivity of glass substrates. [Means for solving the problem]

[0012] A glass member for an EUV mask blank according to one aspect of the present disclosure has a first principal surface and a second principal surface facing the opposite direction to the first principal surface. At least a predetermined region of the first principal surface has an arithmetic mean roughness Ra of 1.5 μm or more and 5.0 μm or less in the roughness curve in the direction in which the arithmetic mean roughness Ra is maximum. [Effects of the Invention]

[0013] According to one aspect of this disclosure, the arithmetic mean roughness Ra of a predetermined region is 1.5 μm or more and 5.0 μm or less. Since the predetermined region has an appropriate surface roughness, a dressing effect is obtained when grinding of the predetermined region begins, and a dressing effect is obtained during the production of the glass substrate. Therefore, interruptions in the production of the glass substrate for dressing can be suppressed, and the productivity of the glass substrate can be improved. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a flowchart showing a method for manufacturing an EUV mask blank according to one embodiment. [Figure 2] Figure 2 is a cross-sectional view showing an example of a glass substrate for EUV mask blanks. [Figure 3] Figure 3 is a plan view of the glass substrate for the EUV mask blank shown in Figure 2. [Figure 4] Figure 4 is a cross-sectional view showing an example of an EUV mask blank. [Figure 5] Figure 5 is a cross-sectional view showing an example of an EUV mask. [Figure 6] Figure 6 is a front view showing an example of a wire saw. [Figure 7] Figure 7 is a plan view showing an example of a glass component for an EUV mask blank. [Figure 8] Figure 8 is a perspective view showing an example of a grinding machine. [Figure 9] Figure 9(A) shows the surface profile of the glass plate according to Example 1, Figure 9(B) shows the surface profile of the glass plate according to Example 2, Figure 9(C) shows the surface profile of the glass plate according to Example 3, and Figure 9(D) shows the surface profile of the glass plate according to Example 4. [Figure 10]FIG. 10(A) is a diagram showing the change over time of the grinding rate when grinding the glass plate according to Example 1 during the process of repeatedly grinding a glass plate having the same surface roughness as in Example 4. FIG. 10(B) is a diagram showing the change over time of the grinding rate when grinding the glass plate according to Example 2 during the process of repeatedly grinding a glass plate having the same surface roughness as in Example 4. FIG. 10(C) is a diagram showing the change over time of the grinding rate when grinding the glass plate according to Example 3 during the process of repeatedly grinding a glass plate having the same surface roughness as in Example 4.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding configurations are denoted by the same reference numerals, and the description thereof may be omitted. In the specification, "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value.

[0016] Referring to FIG. 1, a method for manufacturing an EUV mask blank according to an embodiment will be described. As shown in FIG. 1, the method for manufacturing an EUV mask blank includes, for example, steps S101 to S109. Step S101 is included in the method for manufacturing a glass member. Steps S102 to S106 are included in the method for manufacturing a glass substrate.

[0017] As shown in FIGS. 2 and 3, the glass substrate 210 includes a first main surface 211 and a second main surface 212 opposite to the first main surface 211. The first main surface 211 is rectangular. In this specification, the rectangular shape includes a shape with chamfered corners. Also, the rectangle includes a square. The second main surface 212 is opposite to the first main surface 211. The second main surface 212 is also rectangular, like the first main surface 211.

[0018] The glass substrate 210 also includes four end faces 213, four first chamfered faces 214, and four second chamfered faces 215. The end faces 213 are perpendicular to the first main face 211 and the second main face 212. The first chamfered faces 214 are formed at the boundary between the first main face 211 and the end face 213. The second chamfered faces 215 are formed at the boundary between the second main face 212 and the end face 213. In this embodiment, the first chamfered faces 214 and the second chamfered faces 215 are so-called C-chamfered faces, but they may also be R-chamfered faces.

[0019] The glass of the glass substrate 210 is preferably quartz glass containing TiO2. Compared to general soda-lime glass, quartz glass has a smaller coefficient of linear expansion and less dimensional change due to temperature changes. The quartz glass may contain 80% to 95% by mass of SiO2 and 4% to 17% by mass of TiO2. When the TiO2 content is 4% to 17% by mass, the coefficient of linear expansion at room temperature is almost zero, and there is almost no dimensional change at room temperature. The quartz glass may contain third components or impurities other than SiO2 and TiO2.

[0020] In a plan view, the dimensions of the glass substrate 210 are, for example, 152 mm in length and 152 mm in width. The length and width dimensions may be greater than 152 mm.

[0021] The glass substrate 210 has a central region 211A and a peripheral region 211B on its first main surface 211. The central region 211A is a square region excluding the rectangular frame-shaped peripheral region 211B that surrounds the central region 211A, and is the region that is processed to the desired flatness by steps S102 to S106, and is the quality assurance region. The quality assurance region has a size of, for example, 142 mm in length and 142 mm in width. The length and width dimensions may be 142 mm or more. The four sides of the central region 211A are parallel to the four end faces 213. The center of the central region 211A coincides with the center of the first main surface 211.

[0022] Although not shown in the figures, the second main surface 212 of the glass substrate 210 also has a central region and a peripheral region, similar to the first main surface 211. The central region of the second main surface 212 is a square region, similar to the central region of the first main surface 211, and is the region that is processed to the desired flatness by steps S102 to S106 in Figure 1, and is the quality assurance region. The quality assurance region has dimensions of, for example, 142 mm in length and 142 mm in width. The length and width dimensions may be 142 mm or more.

[0023] Step S101 includes obtaining a plate-shaped glass member 110 by slicing the glass block 10 with a wire saw 20, as shown in Figure 6. The wire saw 20, as shown in Figure 6, includes, for example, a supply reel 21, a retrieval reel 22, a pair of guide rollers 23 and 24, and a wire 25.

[0024] The wire saw 20 pulls out wire 25 from the supply reel 21, winds the pulled-out wire 25 around a pair of guide rollers 23 and 24 and moves it back and forth, and finally winds it onto the recovery reel 22. Abrasive grains may be fixed to the wire 25, or abrasive grains may be supplied. The abrasive grains are, for example, diamond abrasive grains.

[0025] The pair of guide rollers 23 and 24 each have multiple guide grooves on their outer circumference, arranged at equal pitches in the direction of the rotation axis. The multiple guide grooves arrange the wires 25 at equal pitches. The pitch of the wires 25 is determined according to the target thickness of the glass member 110. The glass block 10 can be cut into multiple glass members 110 at once.

[0026] The wire saw 20 repeatedly feeds the wire 25 from the supply reel 21 to the retrieval reel 22 and returns the wire 25 from the retrieval reel 22 to the supply reel 21. In each cycle, the amount of wire 25 fed A is greater than the amount of wire 25 returned B. Therefore, the wire 25 gradually moves from the supply reel 21 to the retrieval reel 22.

[0027] As shown in Figure 7, the glass member 110 has a stripe pattern of irregularities on its first main surface 111. In Figure 7, the direction parallel to the stripes of the irregularities is the X-axis direction, and the direction perpendicular to the stripes of the irregularities is the Y-axis direction. The Y-axis direction is the direction in which the arithmetic mean roughness Ra of the first main surface 111 is maximized. The X-axis direction is the direction in which the arithmetic mean roughness Ra of the first main surface 111 is minimized.

[0028] The first main surface 111 is the cut surface cut by the wire 25. The X-axis direction is the direction in which the wire 25 is moved when slicing the glass block 10 with the wire saw 20 (left-right direction in Figure 6). The Y-axis direction is the direction in which the glass block 10 is moved when slicing the glass block 10 with the wire saw 20 (up-down direction in Figure 6).

[0029] The height difference of the bumps and the pitch of the bumps can be adjusted mainly by the diameter of the wire 25 and the difference (AB) between the amount A that the wire 25 is fed and the amount B that the wire 25 is returned. The larger the diameter of the wire 25, the greater the height difference of the bumps and the pitch of the bumps. Also, the larger the difference (AB), the greater the height difference of the bumps and the pitch of the bumps.

[0030] The glass member 110 has a second main surface 112 facing the opposite direction to the first main surface 111. The second main surface 112 is a cut surface cut by the wire 25, similar to the first main surface 111. Therefore, the second main surface 112 also has a stripe pattern of irregularities, similar to the first main surface 111. The surface roughness of the second main surface 112 is the same as that of the first main surface 111.

[0031] Step S102 includes obtaining a glass substrate 210 by grinding the glass member 110 with a grinding machine 90, as shown in Figure 8. The grinding machine 90 is a double-sided grinding machine that grinds the first main surface 111 and the second main surface 112 of the glass member 110 simultaneously. The grinding machine 90 may also be a single-sided grinding machine, and the first main surface 111 and the second main surface 112 may be ground sequentially.

[0032] The grinding machine 90 includes a lower platen 91, an upper platen 92, a carrier 93, a sun gear 94, and an internal gear 95. The lower platen 91 is positioned horizontally, and a lower grinding pad 96 is attached to the upper surface of the lower platen 91. The upper platen 92 is positioned horizontally, and an upper grinding pad 97 is attached to the lower surface of the upper platen 92. Abrasive grains are fixed to the lower grinding pad 96 and the upper grinding pad 97, respectively. The abrasive grains are not particularly limited, but for example, diamond abrasive grains.

[0033] The carrier 93 horizontally holds the glass members 110 between the lower platen 91 and the upper platen 92. Each carrier 93 holds one glass member 110, but may hold multiple members. The carrier 93 is positioned radially outward of the sun gear 94 and radially inward of the internal gear 95. Multiple carriers 93 are arranged around the sun gear 94 at intervals. The sun gear 94 and the internal gear 95 are arranged concentrically and mesh with the outer gear 93a of the carrier 93.

[0034] The grinding machine 90 is, for example, a 4-way type, in which the lower platen 91, upper platen 92, sun gear 94, and internal gear 95 rotate around the same vertical rotational centerline. The lower platen 91 and upper platen 92 rotate in opposite directions, pressing the lower grinding pad 96 against the lower surface of the glass member 110 and the upper grinding pad 97 against the upper surface of the glass member 110. At least one of the lower platen 91 and upper platen 92 supplies grinding fluid to the glass member 110. The grinding fluid is supplied between the glass member 110 and the lower grinding pad 96. The grinding fluid is also supplied between the glass member 110 and the upper grinding pad 97.

[0035] For example, the lower platen 91, the sun gear 94, and the internal gear 95 rotate in the same direction when viewed from above. These rotation directions are opposite to the rotation direction of the upper platen 92. The carrier 93 rotates on its axis while revolving around a circle. The direction of the carrier 93's revolution is the same as the rotation directions of the sun gear 94 and the internal gear 95. On the other hand, the direction of the carrier 93's rotation is determined by the relative magnitudes of the product of the rotation speed of the sun gear 94 and the pitch circle diameter, and the product of the rotation speed of the internal gear 95 and the pitch circle diameter. If the product of the rotation speed of the internal gear 95 and the pitch circle diameter is greater than the product of the rotation speed of the sun gear 94 and the pitch circle diameter, then the direction of the carrier 93's rotation and its revolution will be the same. On the other hand, if the product of the rotational speed of the internal gear 95 and the pitch circle diameter is smaller than the product of the rotational speed of the sun gear 94 and the pitch circle diameter, the direction of rotation of the carrier 93 and the direction of revolution of the carrier 93 will be opposite.

[0036] As described above, the glass member 110 is ground using a grinding pad on which abrasive grains are fixed. The grinding pad includes, for example, a lower grinding pad 96 and an upper grinding pad 97. The lower grinding pad 96 grinds one of the first main surface 111 and the second main surface 112 of the glass member 110, and the upper grinding pad 97 grinds the other of the first main surface 111 and the second main surface 112 of the glass member 110. Alternatively, the lower grinding pad 96 may grind the first main surface 111 and the second main surface 112 in sequence.

[0037] At least a predetermined area of ​​the first main surface 111 of the glass member 110 has an arithmetic mean roughness Ra of 1.5 μm or more and 5.0 μm or less in the roughness curve in the direction (Y-axis direction) where the arithmetic mean roughness Ra is maximum. The arithmetic mean roughness Ra is measured in accordance with JIS B0601:2013. The arithmetic mean roughness Ra represents the average value of the height of the convexity and the depth of the concaveness.

[0038] If the arithmetic mean roughness Ra of a predetermined region is 1.5 μm or more and 5.0 μm or less, the predetermined region has an appropriate surface roughness, so a dressing effect is obtained when grinding of the predetermined region begins and a dressing effect is obtained during the production of the glass substrate. Therefore, interruptions in the production of the glass substrate due to dressing can be suppressed, and the productivity of the glass substrate can be improved. The arithmetic mean roughness Ra of the predetermined region is preferably 2.5 μm or more, and more preferably 3.0 μm or more. Also, the arithmetic mean roughness Ra of the predetermined region is preferably 4.0 μm or less.

[0039] In the aforementioned predetermined region, it is preferable that the skewness Rsk is greater than 0.0 in the roughness curve in the direction (Y-axis direction) where the arithmetic mean roughness Ra is maximum. The skewness Rsk is measured in accordance with JIS B0601:2013. The skewness Rsk represents the degree of bias (skewness) in the height distribution. If the skewness Rsk is greater than 0.0, there are more convexities than concaves, and the grinding pad can be machined efficiently. The skewness Rsk is more preferably 0.1 or greater. Furthermore, the skewness Rsk is more preferably 1.0 or less.

[0040] In the aforementioned predetermined region, it is preferable that the kurtosis Rku is less than 3.0 in the roughness curve in the direction (Y-axis direction) where the arithmetic mean roughness Ra is maximum. Kurtosis Rku is measured in accordance with JIS B0601:2013. Kurtosis Rku represents the sharpness (kurtosis) of the height distribution. When the height distribution is a normal distribution, the kurtosis Rku is 3.0. If the kurtosis Rku is less than 3.0, the tip of the convex is moderately rounded, the durability of the convex is high, and the polishing pad can be effectively abraded. More preferably, the kurtosis Rku is 2.5 or less. More preferably, the kurtosis Rku is 1.0 or more.

[0041] In the aforementioned predetermined region, the average element length RSm is preferably 200 μm to 500 μm in the roughness curve in the direction (Y-axis direction) where the arithmetic mean roughness Ra is maximum. The average element length RSm is measured in accordance with JIS B0601. The average element length RSm represents the average pitch of the convexity. If the average element length RSm is 200 μm to 500 μm, the density of convexity is appropriately high, and the polishing pad can be efficiently machined. The average element length RSm is more preferably 400 μm to 500 μm.

[0042] The predetermined region is preferably the outer periphery of the first main surface 111. The outer periphery of the first main surface 111 refers to the region within 10 mm from the outer periphery of the first main surface 111. The outer periphery of the first main surface 111 is more likely to come into contact with the grinding pad strongly than the central part of the first main surface 111, and thus more likely to exhibit the dressing effect of the grinding pad.

[0043] The predetermined region is more preferably at least one of the regions X1 and X2 (see Figure 7) within 10 mm from two of the four sides of the first main surface 111 that are parallel to the Y-axis direction. Regions X1 and X2 tend to have a larger arithmetic mean roughness Ra than the central region X3 (see Figure 7), and are more likely to exhibit the dressing effect of the grinding pad.

[0044] Next, an example of the relationship between the surface roughness of a glass plate and the grinding rate will be explained with reference to Figures 9 and 10 and Table 1. Figure 9 shows the surface profiles of the glass plates for Examples 1 to 4. Table 1 shows the surface roughness of the glass plates for Examples 1 to 4.

[0045] [Table 1]

[0046] The surface roughness data shown in Table 1 was measured in region X1 shown in Figure 7. The surface roughness data measured in region X2, also shown in Figure 7, was similar to that measured in region X1. Furthermore, the arithmetic mean roughness Ra measured in region X3 was smaller than the arithmetic mean roughness Ra measured in regions X1 and X2.

[0047] The glass plate in Example 1 was obtained by slicing a glass block 10 with a wire saw 20. The glass plate in Example 2 was obtained by slicing with a wire saw 20 and then grinding with a grinder 90 for 15 seconds. The glass plate in Example 3 was obtained by slicing with a wire saw 20 and then grinding with a grinder 90 for 30 seconds. The glass plate in Example 4 was obtained by slicing with a wire saw 20 and then grinding with a grinder 90 for 900 seconds.

[0048] Figure 10 shows the change in grinding rate when grinding glass plates with the same surface roughness as in Example 4, and when grinding glass plates according to Examples 1 to 3. In Figure 10, the horizontal axis represents the batch size, and the vertical axis represents the grinding rate.

[0049] The glass plates in Examples 1 and 2 had an arithmetic mean roughness Ra of 1.5 μm or more and 5.0 μm or less in region X1, so the grinding rate could be recovered as shown in Figures 10(A) and 10(B). On the other hand, the glass plate in Example 3 had an arithmetic mean roughness Ra of less than 1.5 μm in region X1, so the grinding rate could not be recovered as shown in Figure 10(C).

[0050] It is preferable that the grinding machine 90 grinds glass members 110 having an arithmetic mean roughness Ra of 1.5 μm or more and 5.0 μm or less in a predetermined area for each batch. The grinding pad can be resurfaced at the start of each batch, and a decrease in the grinding rate can be suppressed. The grinding machine 90 may also grind glass members 110 having an arithmetic mean roughness Ra of 1.5 μm or more and 5.0 μm or less in a predetermined area and glass members having an arithmetic mean roughness Ra of less than 1.5 μm in a predetermined area simultaneously in a single batch.

[0051] Although not shown in the figures, the method for manufacturing a glass substrate may include grinding the first main surface 111 of the glass member 110 with a first grinding machine, and grinding the first main surface 111 that has been ground with the first grinding machine with a second grinding machine. In this case, the method for manufacturing a glass substrate may include grinding the first main surface 111 of the glass member 110 with the second grinding machine at a desired timing without grinding it with the first grinding machine.

[0052] The first grinding machine and the second grinding machine are different. For example, the first grinding machine is a primary grinding machine and the second grinding machine is a secondary grinding machine. By grinding the glass members 110 that have not been primary ground with the secondary grinding machine, the grinding pad of the second grinding machine can be resurfaced. The secondary grinding machine may grind both the primary ground glass members 110 and the unground glass members 110 simultaneously in a single batch.

[0053] Step S103 includes polishing the first main surface 211 and the second main surface 212 of the glass substrate 210. In this embodiment, the first main surface 211 and the second main surface 212 are polished simultaneously using a double-sided polishing machine (not shown), but they may also be polished sequentially using a single-sided polishing machine (not shown). In step S103, the glass substrate 210 is polished while supplying polishing slurry between the polishing pad and the glass substrate 210.

[0054] As polishing pads, for example, urethane-based polishing pads, nonwoven fabric-based polishing pads, or suede-based polishing pads can be used. The polishing slurry contains an abrasive and a dispersion medium. The abrasive is, for example, cerium oxide particles. The dispersion medium is, for example, water or an organic solvent. The first main surface 211 and the second main surface 212 may be polished multiple times with abrasives of different materials or particle sizes.

[0055] The abrasive used in step S103 is not limited to cerium oxide particles, but may also be silicon oxide particles, aluminum oxide particles, zirconium oxide particles, titanium oxide particles, diamond particles, or silicon carbide particles, for example.

[0056] Step S104 includes measuring the surface shapes of the first main surface 211 and the second main surface 212 of the glass substrate 210. For measuring the surface shapes, for example, a non-contact measuring instrument is used so as not to damage the surface. The measuring instrument measures the surface shapes of the central region 211A of the first main surface 211 and the central region of the second main surface 212.

[0057] Step S105 includes referring to the measurement results from step S104 and locally processing the first main surface 211 and the second main surface 212 of the glass substrate 210 to improve flatness. The first main surface 211 and the second main surface 212 are locally processed in sequence. The order in which they are processed does not matter and is not particularly limited.

[0058] For localized machining, at least one of the following methods may be used: GCIB (Gas Cluster Ion Beam) method, PCVM (Plasma Chemical Vaporization Machining) method, magnetic fluid polishing method, and polishing with a rotary polishing tool.

[0059] Step S106 includes performing finish polishing on the first main surface 211 and the second main surface 212 of the glass substrate 210. In this embodiment, the first main surface 211 and the second main surface 212 are polished simultaneously using a double-sided polishing machine (not shown), but they may be polished sequentially using a single-sided polishing machine (not shown). In step S106, the glass substrate 210 is polished while supplying polishing slurry between the polishing pad and the glass substrate 210. The polishing slurry contains an abrasive. The abrasive is, for example, colloidal silica particles.

[0060] Step S107 includes forming a conductive film 240, as shown in Figure 4, on the central region of the second main surface 212 of the glass substrate 210. The conductive film 240 is used to attract the EUV mask 201 (see Figure 5), which will be described later, to the electrostatic chuck of the exposure apparatus. The conductive film 240 is formed of, for example, chromium nitride (CrN). For example, sputtering can be used as a method for forming the conductive film 240.

[0061] Step S108 includes forming a multilayer reflective film 220, as shown in Figure 4, on the central region 211A of the first main surface 211 of the glass substrate 210. The multilayer reflective film 220 reflects EUV light. The multilayer reflective film 220 is formed by alternately stacking high refractive index layers and low refractive index layers. The high refractive index layers are formed from silicon (Si), for example, and the low refractive index layers are formed from molybdenum (Mo), for example. As a method for depositing the multilayer reflective film 220, sputtering methods such as ion beam sputtering and magnetron sputtering are used.

[0062] Step S109 includes forming an absorption film 230, as shown in Figure 4, on the multilayer reflective film 220 formed in step S108. The absorption film 230 absorbs EUV. The absorption film 230 may also be a phase-shift film, which may shift the phase of EUV. The absorption film 230 is formed from a single metal, alloy, nitride, oxide, oxynitride, etc., containing at least one element selected from tantalum (Ta), chromium (Cr), and palladium (Pd). For example, sputtering can be used as a method for depositing the absorption film 230.

[0063] In this embodiment, steps S108 to S109 are performed after step S107, but they may also be performed before step S107.

[0064] By following the steps S101 to S109 described above, the EUV mask blank 200 shown in Figure 4 is obtained. The EUV mask blank 200 has a conductive film 240, a glass substrate 210, a multilayer reflective film 220, and an absorption film 230 in this order. In addition to the conductive film 240, glass substrate 210, multilayer reflective film 220, and absorption film 230, the EUV mask blank 200 may also contain another film.

[0065] For example, the EUV mask blank 200 may further include a low-reflection film. The low-reflection film is formed on the absorption film 230. Subsequently, an aperture pattern 231 is formed on both the low-reflection film and the absorption film 230. The low-reflection film is used to inspect the aperture pattern 231 and has lower reflectivity than the absorption film 230 with respect to inspection light. The low-reflection film is formed, for example, from TaON or TaO. For example, sputtering can be used as a method for depositing the low-reflection film.

[0066] Furthermore, the EUV mask blank 200 may also include a protective film. The protective film is formed between the multilayer reflective film 220 and the absorption film 230. The protective film protects the multilayer reflective film 220 from being etched when the absorption film 230 is etched to form an aperture pattern 231 in the absorption film 230. The protective film is formed of, for example, Ru, Si, or TiO2. For example, sputtering can be used as a method for depositing the protective film.

[0067] The EUV mask 201 shown in Figure 5 is obtained by forming an aperture pattern 231 on an absorption film 230. Photolithography and etching methods are used to form the aperture pattern 231. Therefore, the resist film used to form the aperture pattern 231 may be included in the EUV mask blank 200.

[0068] The above describes the glass component for EUV mask blanks, its manufacturing method, and the manufacturing method for the glass substrate for EUV mask blanks related to this disclosure. However, this disclosure is not limited to the embodiments described above. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope described in the claims. These also naturally fall within the technical scope of this disclosure. [Explanation of symbols]

[0069] 110 Glass components 111 First Main Surface 112 Second Main Surface

Claims

1. It has a first main surface and a second main surface facing the opposite direction from the first main surface, A method for manufacturing a glass member for an EUV mask blank, wherein at least a predetermined region of the first main surface has an arithmetic mean roughness Ra of 1.5 μm or more and 5.0 μm or less in the roughness curve in the direction in which the arithmetic mean roughness Ra is maximum, A method for manufacturing a glass component for an EUV mask blank, comprising obtaining the glass component for the EUV mask blank by slicing a glass block with a wire saw.

2. The method for manufacturing a glass member for an EUV mask blank according to claim 1, wherein the predetermined region is a roughness curve in the direction in which the arithmetic mean roughness Ra is maximum, and the skewness Rsk is greater than 0.

0.

3. The method for manufacturing a glass member for an EUV mask blank according to claim 1, wherein the predetermined region is a roughness curve in the direction in which the arithmetic mean roughness Ra is maximum, and the kurtosis Rku is less than 3.

0.

4. The method for manufacturing a glass member for an EUV mask blank according to claim 1, wherein the predetermined region is a roughness curve in the direction in which the arithmetic mean roughness Ra is maximum, and the average element length RSm is 200 μm to 500 μm.

5. The method for manufacturing a glass member for an EUV mask blank according to claim 1, wherein the predetermined region is the outer periphery of the first main surface.

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