JP6297512B2 - Manufacturing method of mask blank substrate, manufacturing method of substrate with multilayer film, manufacturing method of mask blank, and manufacturing method of transfer mask - Google Patents

Description

  The present invention relates to a method for manufacturing a mask blank substrate, a method for manufacturing a reflective substrate with a multilayer film, a method for manufacturing a mask blank using a mask blank substrate or a substrate with a multilayer reflective film, and a transfer mask using the mask blank. In particular, a method for manufacturing a mask blank substrate having high smoothness and flatness and a low defect density, a method for manufacturing a reflective substrate with a multilayer film, a substrate for mask blank, or a substrate with a multilayer reflective film is used. The present invention relates to a mask blank manufacturing method and a transfer mask manufacturing method using the mask blank.

  In recent years, in semiconductor devices, the density and accuracy of highly integrated circuits have been further increased. As a result, there is a demand for smoothing, flattening, and reducing defects at a finer size for mask blank substrates, mask blanks, and transfer masks used for circuit pattern transfer.

  For example, as a mask blank used in the semiconductor design rule 1 × nm generation (half pitch (hp) 14 nm, 10 nm, etc.), a reflective mask blank for EUV exposure, a binary mask blank for ArF excimer laser exposure, and a phase shift mask blank, In addition, there are nanoimprint mask blanks and the like, but in the mask blanks used in these generations, there is a problem of defects of 30 nm class (SEVD (Sphere Equivalent Volume Diameter) of 23 nm or more and 34 nm or less). For this reason, it is preferable that the number of defects of the 30 nm class is as small as possible on the main surface of the substrate used for the mask blank (that is, the surface on the transfer pattern forming side). Further, in a high-sensitivity defect inspection apparatus that performs defect inspection of 30 nm-class defects, the surface roughness affects background noise. That is, if the smoothness is insufficient, a large number of pseudo defects due to surface roughness are detected, and defect inspection cannot be performed. For this reason, the main surface of the substrate used for the mask blank used in the semiconductor design rule 1 × nm generation is required to have a smoothness of not more than 0.08 nm in terms of root mean square roughness (Rms).

  Up to now, various processing methods have been proposed to make the main surface of the mask blank substrate have a high smoothness, a low defect, and substantially no protrusions. It has been difficult to realize a substrate having a surface.

  2. Description of the Related Art In recent years, a processing method using catalyst-based etching (hereinafter also referred to as “CARE”) has been proposed as a processing method for a substrate that requires a low defect and high smoothness with substantially no protrusions on the main surface. In catalyst-based etching (CARE) processing, a hydroxyl group is generated as an active species from a molecule in a processing fluid adsorbed on a processing reference surface formed from a catalyst substance, and the active species approaches or contacts the processing reference surface. It is considered that the fine convex portions on the surface undergo a hydrolysis reaction and the fine convex portions are selectively removed. Patent Document 1 describes a processing method by catalyst-based etching using a metal catalyst.

  In Patent Document 1, in the presence of water, the processing reference surface of the catalyst substance is brought into contact with or close to the surface of the workpiece made of a solid oxide such as glass, and the processing reference surface and the surface of the workpiece are moved relative to each other. In addition, a solid oxide processing method is described in which a hydrolysis product is removed from the surface of the workpiece, and the surface of the workpiece is processed (hereinafter, the solid oxide processing method is also referred to as a CARE processing method). Called). As the catalyst material, a material containing a metal element and having an electron d orbit near the Fermi level is used. Specific metal elements include, for example, platinum (Pt), gold (Au), silver ( Ag), copper (Cu), nickel (Ni), chromium (Cr), and molybdenum (Mo). It is described that the catalyst material need not be bulk, and may be a thin film formed by sputtering or the like on the surface of a base material (pad) that is inexpensive and has good shape stability. . In addition, as a base material for forming a catalyst material on the surface, a hard elastic material may be used. For example, it is described that a fluorine-based rubber can be used.

International Publication No. 2013/084934

  As described in the background, in the advanced mask blank substrate, the root mean square roughness (Rms) is 0.08 nm or less with high smoothness and high flatness, and 30 nm-class micro defects are reduced. Is required.

For substrates such as synthetic quartz glass, which is a mask blank substrate material for ArF excimer laser exposure, and SiO ₂ —TiO ₂ glass substrate, which is a mask blank substrate material for EUV (Extreme Ultra Violet) exposure, the surface is an oxide. Substrates made of a material containing are becoming mainstream. For this reason, when these substrates are CARE processed, the surface roughness is generally reduced, and a main surface having high smoothness can be obtained.
On the other hand, when the substrate main surface after CARE processing obtained using normal temperature water (pure water) as the processing fluid is inspected with a highly sensitive defect inspection apparatus, a micro-sleeve-like defect that can be a concave defect is detected. There was a case. Further, the flatness sometimes does not satisfy the required value.

  The present invention provides a mask blank substrate for manufacturing a mask blank substrate having a main surface with low defects and high smoothness and flatness by reducing the micro-sleeve-like defects on the substrate main surface. It is an object to provide a method, a method for manufacturing a substrate with a multilayer film, a method for manufacturing a mask blank, and a method for manufacturing a transfer mask.

  The present inventor can reduce the surface roughness of the main surface below a predetermined roughness by adjusting the temperature of the processing fluid to a temperature below room temperature, and can reduce defects such as micro-sleeve scratches. And found that the flatness is improved. The present invention has the following configuration.

(Configuration 1)
A substrate preparation step of preparing a mask blank substrate having a main surface made of a material containing an oxide;
The processing reference surface of the catalytic substance and the main surface are brought into contact with or close to each other, and the main surface and the processing reference surface are moved relative to each other while a processing fluid is interposed between the processing reference surface and the main surface. A step of performing catalyst-based etching of the main surface by:
In a method for manufacturing a mask blank substrate having
The method of manufacturing a mask blank substrate, wherein the processing fluid is a liquid that causes hydrolysis on the main surface of the substrate, and the temperature of the processing fluid during the catalyst-based etching is less than room temperature.
(Configuration 2)
2. The method for manufacturing a mask blank substrate according to Configuration 1, wherein at least a main surface of the substrate is cooled to a temperature lower than room temperature during the catalyst-based etching step.
(Configuration 3)
The catalyst reference etching includes a surface plate, a pad formed on the entire surface of the surface plate, and a processing reference surface made of the catalyst material formed on the entire surface of the pad on the side facing the substrate main surface. Is performed using a catalyst surface plate equipped with
And the said surface plate consists of low thermal expansion materials, The manufacturing method of the board | substrate for mask blanks of the structure 1 or 2 characterized by the above-mentioned.
(Configuration 4)
A method for producing a substrate with a multilayer reflective film, comprising: forming a multilayer reflective film on a main surface of the substrate produced by the method for producing a mask blank substrate according to any one of Structures 1 to 3.
(Configuration 5)
With the multilayer reflective film obtained by the manufacturing method of the board | substrate with a multilayer reflective film of the structure 4 on the main surface of the board | substrate obtained by the manufacturing method of the mask blank board | substrate as described in any one of the structures 1 to 3 A mask blank manufacturing method, comprising: forming a transfer pattern thin film on a multilayer reflective film of a substrate.
(Configuration 6)
A method for producing a transfer mask, comprising: patterning a thin film for transfer pattern of a mask blank obtained by the method for producing a mask blank according to Configuration 5, to form a transfer pattern.

According to the present invention, high smoothness is obtained by CARE processing, and by setting the temperature of the processing fluid for CARE processing to less than room temperature, the viscosity of pure water as the processing fluid increases, and the surface plate, base material (pad) And thermal expansion of the catalyst platen made of the catalyst is suppressed. The increase in the viscosity of the processing fluid (pure water) prevents a partial shortage of the processing fluid film (water film) due to the outflow of the processing fluid from the substrate main surface, which is the surface to be processed, and the processing reference surface made of the catalyst material. Suppressing thermal expansion of the platen suppresses deformation of the catalyst platen. The generation of a sleek defect is suppressed by partially eliminating the shortage of the processing fluid film (water film), and the flatness is improved by suppressing the deformation of the catalyst platen.
By this method, it is possible to manufacture a desired mask blank substrate with improved smoothness and flatness of the main surface of the substrate, which is a surface to be processed, and with few micro defects.

  In addition, according to the method for manufacturing a substrate with a multilayer reflective film according to the present invention, a substrate with a multilayer reflective film is manufactured using the substrate obtained by the above-described substrate manufacturing method. A substrate with a film can be manufactured.

  Further, according to the mask blank manufacturing method of the present invention, the mask is obtained using the substrate obtained by the above-described substrate manufacturing method or the substrate with the multilayer reflective film obtained by the above-described method of manufacturing the substrate with the multilayer reflective film. Since a blank is manufactured, a mask blank having desired characteristics can be manufactured.

  Further, according to the method for manufacturing a transfer mask according to the present invention, a transfer mask is manufactured using the mask blank obtained by the above-described mask blank manufacturing method, so that a transfer mask having desired characteristics can be obtained. Can be manufactured.

It is a fragmentary sectional view showing an important section outline composition in catalyst standard etching of the present invention. It is a fragmentary sectional view showing composition of a local catalyst standard etching processing device which performs local processing by catalyst standard etching to a mask blank substrate. It is a top view which shows the structure of the local catalyst reference | standard etching processing apparatus which performs the local process by a catalyst reference | standard etching with respect to the mask blank board | substrate.

  Hereinafter, a method for manufacturing a mask blank substrate according to an embodiment of the present invention, a method for manufacturing a substrate with a multilayer reflective film using this substrate, a method for manufacturing a mask blank using this substrate or a substrate with a multilayer reflective film, and A method for manufacturing a transfer mask using this mask blank will be described in detail with reference to the timely drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof may be simplified or omitted.

Embodiment 1 FIG.
In the first embodiment, a method for manufacturing a mask blank substrate and a substrate processing apparatus will be described.

In the first embodiment, a mask blank substrate preparation step for preparing a substrate whose main surface is made of an oxide-containing material, a processing reference surface of the catalyst substance is brought into contact with or close to the main surface of the substrate, and a processing reference surface A mask blank substrate is manufactured by a substrate processing step in which the main surface of the substrate is processed by catalyst-based etching while a processing fluid is interposed between the main surface and the main surface.
Hereinafter, each process will be described in detail.

1. Mask Blank Substrate Preparation Step In the mask blank substrate manufacturing method, first, a substrate whose main surface is made of a material containing an oxide is prepared.

The substrate to be prepared is, for example, a substrate made of a material containing an oxide as a whole, a substrate in which a thin film made of a material containing an oxide is formed on an upper surface used as a main surface, or both an upper surface and a lower surface used as a main surface A substrate on which a thin film made of a material containing an oxide is formed.
The substrate on which the thin film is formed may be a substrate on which a thin film made of a material containing an oxide is formed on an upper surface or a lower surface used as a main surface of a substrate body made of a material containing an oxide, or contains an oxide. A substrate in which a thin film made of a material containing an oxide is formed on the upper or lower surface used as the main surface of a substrate body (base) made of a material other than the material may be used.

Examples of the material of the substrate and the substrate body made of a material containing an oxide include glass such as synthetic quartz glass, soda lime glass, borosilicate glass, aluminosilicate glass, SiO ₂ —TiO ₂ glass, and glass ceramics. .
Specifically, as an oxide for forming a thin film, silicon oxide (SiO _x , (x> 0)), metal silicide oxide containing metal and silicon (Me _x Si _y O _z , (Me: metal, x> 0, y> 0, and z> 0)). A thin film made of a material containing such an oxide can be formed by, for example, vapor deposition, sputtering, or electroplating.
Further, the above-described oxide may contain elements such as nitrogen, carbon, hydrogen, fluorine and the like without departing from the effects of the present invention.
The substrate to be prepared is preferably made of a silicon substrate (SiO _x (x> 0) on the upper surface and the lower surface, which are the main surfaces of the glass substrate main body and the main surface of the glass substrate main body, which is difficult to plastically deform and easily obtain a high smoothness main surface. )).

The substrate to be prepared is a mask blank substrate. The mask blank substrate may be used for manufacturing any of a reflective mask blank, a binary mask blank, a phase shift mask blank, and a nanoimprint mask blank. In the binary mask blank, the material of the light shielding film may be any of MoSi, Ta, and Cr. The phase shift mask blank may be any of a halftone type phase shift mask blank, a Levenson type phase shift mask blank, and a chromeless type phase shift mask blank. The substrate material used for the reflective mask blank needs to be a material having low thermal expansion. For this reason, the substrate material used for the reflective mask blank for EUV exposure is preferably, for example, SiO ₂ —TiO ₂ glass. Moreover, the substrate material used for the transmission type mask blank needs to be a material having translucency with respect to the exposure wavelength to be used. For this reason, as a substrate material used for the binary mask blank and the phase shift mask blank for ArF excimer laser exposure, for example, synthetic quartz glass is preferable.

  The substrate to be prepared is preferably a substrate whose main surface is polished using fixed abrasive grains, loose abrasive grains, or the like. For example, the upper and lower surfaces used as the main surface are polished using the following processing method so as to have predetermined smoothness and flatness. Even when the lower surface is not used as the main surface, the lower surface is also polished using the following processing method as necessary so as to have predetermined smoothness and flatness. However, it is not necessary to perform all the following processing methods, and it is performed by selecting appropriately so as to have predetermined smoothness and flatness.

As a processing method for reducing the surface roughness, for example, there are polishing and lapping using abrasive grains such as cerium oxide and colloidal silica.
As processing methods for improving the flatness, for example, magneto-rheological fluid polishing (MRF), local chemical mechanical polishing (LCMP), gas cluster ion beam etching (Gas Cluster Ion Beam Etching). : GCIB), and dry chemical planarization (DCP) using local plasma etching.

MRF is a local processing method in which a magnetic polishing slurry obtained by mixing a polishing slurry in a magnetic fluid is brought into contact with a workpiece at high speed and polishing is performed locally by controlling the residence time of the contact portion.
In LCMP, a polishing slurry containing abrasive grains such as a small-diameter polishing pad and colloidal silica is used. By controlling the residence time of the contact portion between the small-diameter polishing pad and the workpiece, the surface of the workpiece is mainly projected. This is a local processing method for polishing a portion.
GCIB is a gas produced by ejecting a gas reactive substance (source gas) at normal temperature and pressure while adiabatically expanding into a vacuum apparatus to generate a gas cluster, and irradiating it with an electron beam to ionize it. This is a local processing method in which cluster ions are accelerated by a high electric field to form a gas cluster ion beam, which is irradiated to a workpiece to be etched.

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.
In order to improve the surface roughness damaged by the above-described processing method for improving the flatness, as a processing method for improving the surface roughness while maintaining the flatness as much as possible, for example, float polishing, EEM (Elastic) Emission Machining) and hydroplane polishing.

  In order to shorten the processing time by the catalyst reference etching, it is preferable that the main surface of the substrate to be prepared has a root mean square roughness (Rms) of 0.3 nm or less, more preferably 0.15 nm or less.

2. Mask blank substrate processing step Next, the processing reference surface of the catalyst material is brought into contact with or close to the main surface of the substrate, and a processing fluid having a temperature of less than room temperature is interposed between the processing reference surface and the main surface, The main surface is processed by catalyst-based etching (CARE).
When both the upper surface and the lower surface of the substrate are used as the main surface, the lower surface CARE processing may be performed after the upper surface CARE processing, or the upper surface CARE processing may be performed after the lower surface CARE processing. CARE processing on both sides of the lower surface may be performed simultaneously. Even if the lower surface is not used as the main surface, the lower surface is also processed by catalyst-based etching as necessary. When CARE processing is also performed on the lower surface that is not used as the main surface, the upper surface used as the main surface is required to have high quality in terms of defect quality. It is preferable to perform processing.

  In this case, as shown in FIG. 1 for explaining the catalyst reference etching by the schematic cross-sectional view of the catalyst surface plate 32 and the substrate M, first, the processing reference surface 33 made of the catalyst substance 321 is formed on the main surface M1 of the substrate M. Arrange to face each other. Here, the catalyst surface plate 32 includes a surface plate 323, a base material (pad) 322 formed on the entire surface of the surface plate 323 so as to cover the surface plate 323, and the main surface M 1 of the substrate M. And a catalyst substance 321 formed on the entire surface of the pad 322. The pad 322 is made of a brittle material having a stable shape and moderate elasticity, such as fluorine rubber or porous foamed urethane, and the surface plate 323 has sufficient rigidity to cause deformation. It is made of a material that is difficult and has a low coefficient of thermal expansion, such as stainless steel or ceramics. The catalyst material 321 will be described later. Then, a processing fluid 100 having a temperature lower than room temperature is supplied between the processing reference surface 33 and the main surface M1 through a processing fluid supply pipe 91 formed so as to penetrate the catalyst surface plate 32, and the processing reference surface is supplied. With the processing fluid 101 having a temperature lower than room temperature interposed between the main surface M1 and the processing surface 101, the processing reference surface 33 is brought into contact with or close to the main surface M1, and a predetermined load (processing pressure) is applied to the substrate. The machining reference surface 33 and the main surface M1 are moved relative to each other.

  When the processing reference surface 33 and the main surface M1 are moved relative to each other while the processing fluid 101 is interposed between the processing reference surface 33 and the main surface M1, the processing fluid adsorbed on the processing reference surface 33 is in the processing fluid. The active species generated from the molecules react with the main surface M1 to process the main surface M1. Here, this reaction is a hydrolysis reaction when the substrate surface contains an oxide or an oxide. The active species are generated only on the processing reference surface 33 and deactivated when they are separated from the vicinity of the processing reference surface 33. Therefore, there is almost no reaction with the active species other than the main surface with which the processing reference surface 33 contacts or approaches. In this way, the main surface M1 is processed by the catalyst reference etching. In the processing based on the catalyst-based etching, since no abrasive is used, damage to the mask blank substrate is extremely small, and generation of new defects due to the abrasive can be prevented. Here, an example in which the processing fluid 101 having a temperature lower than room temperature is supplied from the processing fluid supply pipe 91 is shown. This is preferable because the catalyst surface plate 32 can be cooled to below room temperature and the processing fluid 101 is easily interposed between the processing reference surface 33 and the main surface M1 without interruption. The processing fluid supply pipe 91 is not formed inside the catalyst platen 32 but can be provided outside the catalyst platen 32.

The relative motion between the processing reference surface 33 and the main surface M1 is not particularly limited as long as the processing reference surface 33 and the main surface M1 move relatively. When the substrate M is fixed and the processing reference surface 33 is moved, the processing reference surface 33 is fixed and the substrate M is moved, or both the processing reference surface 33 and the substrate M are moved. When the processing reference surface 33 moves, the movement is performed when the processing reference surface 33 rotates around an axis perpendicular to the main surface M1 of the substrate, or when the processing reference surface 33 reciprocates in a direction parallel to the main surface M1 of the substrate M. . Similarly, when the substrate M is moved, the movement is performed around an axis perpendicular to the main surface M1 of the substrate M, or when the substrate M is reciprocated in a direction parallel to the main surface M1 of the substrate M. It is.
The load (processing pressure) applied to the substrate M is, for example, 5 to 350 hPa.
The machining allowance in the process by the catalyst reference etching is, for example, 5 nm to 100 nm. When there is a protrusion protruding from the main surface on the main surface M1 of the substrate M, the machining allowance is preferably set to a value larger than the height of the protrusion. By setting the machining allowance to a value larger than the height of the protrusion, the protrusion can be removed by CARE processing.

  The catalyst substance 321 that forms the processing reference surface 33 may be any material that generates active species that hydrolyze the substrate surface with respect to the processing fluid, and is preferably a material containing a metal element, preferably a transition metal element. For example, at least one metal of elements belonging to Group 4, Group 6, Group 8, Group 9, Group 10, Group 11 and Group 11 of the periodic table and alloys containing them are preferably used. Specifically, platinum (Pt), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), At least one metal selected from tungsten (W), iron (Fe), ruthenium (Ru), copper (Cu), cobalt (Co), nickel (Ni), silver (Ag), and osmium (Os). And an alloy compound containing at least one component of oxygen (O), nitrogen (N), and carbon (C). Examples of the alloy compound described above include oxides, nitrides, carbides, oxynitrides, oxycarbides, nitride carbides, and oxynitride carbides of the above-described alloys. When such an alloy or alloy compound is used, the mechanical durability and chemical stability of the processing reference surface 33 can be improved. These catalyst substances are formed on the pads 322 made of, for example, fluorine rubber as described above.

Area of the working reference face 33 is smaller than the area of the main surface M1 of the substrate M, for ^example, a 100mm ² ~10000mm 2. By downsizing the processing reference surface 33, the substrate processing apparatus can be downsized and high-precision processing can be performed reliably.
Further, the area of the processing reference surface 33 may be larger than the area of the main surface M1 of the substrate M. Since the entire surface of the substrate can be processed, the processing time can be shortened, and the occurrence of defects such as scratches due to the edge of the processing reference surface 33 can be suppressed.

The processing fluid 101 is not particularly limited as long as it does not exhibit solubility in a normal state with respect to a substrate made of a material containing an oxide and induces hydrolysis. By using such a processing fluid, the substrate M is not dissolved by the processing fluid, and unnecessary deformation of the substrate can be prevented. For example, a low concentration alkaline aqueous solution such as pure water, ozone water, carbonated water, hydrogen water, or a KOH aqueous solution, or a low concentration acidic aqueous solution such as a HNO ₃ aqueous solution can be used. In the case where the substrate surface is not normally dissolved by a solution containing halogen-containing molecules, a solution containing halogen-containing molecules can also be used. Here, in particular, pure water is suitable as a processing fluid from the viewpoints of cost, processing characteristics, ease of handling during cleaning, and the like.

The temperature of the processing fluid 101 during CARE processing is set to a temperature lower than room temperature in order to reduce a leak-like defect and increase the flatness after processing. This is a feature of the present invention.
By setting the temperature of the CARE processing fluid to less than room temperature, the viscosity of the processing fluid increases, and thermal expansion of the catalyst material 321, the base material (pad) 322, and the surface plate 323 constituting the catalyst surface plate 32 is suppressed. Is done. In the CARE processing, frictional heat is generated when the processing reference surface 33 and the main surface M1 are relatively moved, and the catalyst surface plate 32 is likely to be thermally deformed. When the catalyst platen 32 is deformed, the shape after processing, particularly flatness, is likely to be lowered. Therefore, the platen 323 is preferably made of a low thermal expansion material such as stainless steel or ceramics.

  When the processing fluid is pure water, the pure water has a viscosity of 0.933 mPa · s at 23 ° C., 1.053 mPa · s at 18 ° C., and 1.201 mPa · s at 13 ° C. When the temperature is lowered, the viscosity increases at a rate of 2% / ° C. or more. The increase in the viscosity of the processing fluid (pure water) is caused by a partial shortage of the processing fluid film (water film) due to the outflow of the processing fluid between the substrate main surface, which is the processing surface, and the processing reference surface made of the catalyst material (processing fluid film is cut off). ). By using a processing fluid of less than room temperature, partial processing fluid film (water film) shortage is prevented and the occurrence of sleek defects is suppressed, and flatness is improved by suppressing deformation of the catalyst platen due to frictional heat. To do. In particular, in order to improve the processing throughput of the mask blank substrate, when processing at a high relative speed between the processing reference surface 33 and the main surface M1 of the substrate M, a partial processing fluid film (water film) due to processing fluid outflow is generated. ) Although shortage is likely to occur, the process fluid film is less likely to be cut by this method of using a processing fluid at a room temperature, and a sleek defect is suppressed.

  Here, normal temperature is the temperature of the external environment when CARE processing is performed, and when the CARE processing device is placed in a clean room or clean booth, it is the temperature in the clean room or clean booth. is there. In the semiconductor-related field, many clean rooms and clean booths are often operated at 23 ° C., and processing conditions and quality control are often performed at an environmental temperature of 23 ° C. mainly in semiconductor manufacturing equipment. The chemicals such as resists and developing solutions are often set to 23 ° C. as a default, and their characteristics are optimized and quality control is performed. Therefore, although the normal temperature is often 23 ° C., it is not limited to that temperature.

  When CARE processing is performed under a reduced pressure from atmospheric pressure, the optimum temperature range decreases overall, and when CARE processing is performed under high pressure, the optimum temperature range increases overall, but the structure of the CARE processing manufacturing apparatus is simplified. Considering the ease of conversion and maintenance, atmospheric pressure treatment is desirable.

  It is preferable that the CARE processing fluid is continuously replaced with the cleaning liquid without interposing the drying process of the mask blank substrate. This is because the substance dissolved in the processing fluid on the substrate surface is removed by the cleaning liquid continuously replaced. Note that, since the processing fluid is continuously replaced with the cleaning liquid, it is desirable that the processing fluid be the same substance as the cleaning liquid. From this point of view, it is preferable that the processing fluid is pure water.

  Next, a substrate manufacturing apparatus (substrate processing apparatus) for CARE processing will be described. 2 and 3 show an example of a substrate processing apparatus for processing the main surface of the substrate by catalytic reference etching. FIG. 2 is a partial cross-sectional view of the substrate processing apparatus, and FIG. 3 is a plan view of the substrate processing apparatus. Hereinafter, a case where the upper surface M1 used as the main surface of the mask blank substrate M (substrate M) is CARE processed using the substrate processing apparatus shown in FIGS. 2 and 3 will be described. When using as the main surface, the upper surface M1 and the lower surface M2 are interchanged, and the lower surface M2 is also CARE processed. Even if the lower surface M2 is not used as the main surface, the lower surface M2 is also CARE processed as necessary. In that case, CARE processing of the upper surface M1 is performed after CARE processing of the lower surface M2.

  The substrate processing apparatus 1 includes a substrate supporting means 2 for supporting a substrate M having a main surface made of an oxide-containing material, a substrate surface creating means 3 having a processing reference surface 33 for a catalytic substance, a substrate temperature adjusting liquid, and a cleaning liquid. In the state where the processing fluid is interposed between the processing reference surface 33 and the main surface, the cleaning fluid supply means 4 for supplying the processing fluid, the processing fluid supply means 9 for supplying the processing fluid between the processing reference surface 33 and the main surface, And a driving means 5 for bringing the processing reference surface 33 into contact with or approaching the main surface.

  The substrate support means 2 is disposed in a cylindrical chamber 6. The chamber 6 includes an opening 61 formed in the center of the bottom 63 of the chamber 6 and a substrate temperature adjusting liquid / cleaning liquid supply means 4 in order to arrange a shaft portion 71 of the relative motion means 7 described later in the chamber 6. In order to discharge the supplied substrate temperature adjusting liquid, the cleaning liquid, and the processing fluid supplied from the processing fluid supply means 9, a discharge port 62 formed on the bottom 63 of the chamber 6 closer to the outer periphery than the opening 61 is provided. I have. In FIG. 2, the state in which the substrate temperature adjusting liquid, the cleaning liquid, and the processing fluid are discharged from the discharge port 62 is indicated by arrows.

  The substrate support means 2 includes a support portion 21 that supports the substrate M and a flat portion 22 that fixes the support portion 21. The support portion 21 has a rectangular shape when the substrate processing apparatus 1 is viewed from above, and includes a receiving portion 21a that supports four sides of the periphery of the lower surface M2 of the substrate M. The planar portion 22 has a circular shape when the substrate processing apparatus 1 is viewed from above.

  The substrate surface creation means 3 includes a catalyst surface plate 31. The catalyst surface plate portion 31 is attached to a catalyst surface plate attachment portion 72 of the relative motion means 7 described later. As shown in FIG. 1, the catalyst platen 31 includes a catalyst platen (catalyst platen main body) 32 including a catalyst substance 321, a base material (pad) 322, and a platen 323, and a processing reference surface. 33. Therefore, the catalyst material constituting the processing reference surface 33 faces the substrate M.

  The overall shape of the catalyst surface plate 32 is not particularly limited. For example, the outer shape of a disk, a sphere, a cylinder, a cone, or a pyramid can be used. The surface shape of the portion of the catalyst surface plate on which the processing reference surface 33 is formed is not particularly limited. For example, a flat, hemispherical, or rounded shape can be used.

  The processing fluid supply means 9 is disposed in a processing fluid supply hole 91 formed in the center of the catalyst surface plate 32 and the catalyst surface plate mounting portion 72, and a processing fluid supply pipe ( FIG. 2 shows a case where the processing fluid supply hole 91 formed in the center of the catalyst platen 32 extends into the catalyst mounting portion 72 and also serves as a processing fluid supply pipe), and is disposed in the arm portion 51. And a piping (not shown) for supplying a processing fluid to the processing fluid supply piping. The processing fluid is supplied to the processing fluid supply piping in the catalyst surface plate mounting portion 72 through the piping in the arm portion 51, and from the processing fluid supply hole 91 formed in the center of the catalyst surface plate 32, the main surface of the substrate M. Supplied on M1. Here, the processing fluid is supplied through a temperature regulator (not shown), but a temperature adjusting mechanism (not shown) is also provided in the arm portion 51 in order to increase the ascending / descending speed of the processing fluid temperature. It is desirable.

  The temperature adjusting liquid / cleaning liquid supply means 4 is provided at the front end of the lower end of the supply pipe 41 and the supply pipe 41 extending from the outside of the chamber 6 toward the main surface M1 of the substrate M placed on the support portion 21. And an injection nozzle 42 for injecting the temperature adjusting liquid and the cleaning liquid toward the main surface M1 of the substrate M placed on the support portion 21. The supply pipe 41 is connected to, for example, a temperature adjustment liquid and cleaning liquid storage tank (not shown), a temperature adjuster (not shown), and a pressurization pump (not shown) provided outside the chamber 6. Yes. The temperature adjustment liquid and the cleaning liquid are supplied to the injection nozzle 42 through the supply pipe 41 and are supplied from the injection nozzle 42 onto the main surface M1 of the substrate M placed on the support portion 21. Here, an example in which the temperature adjusting liquid and the cleaning liquid are made the same substance is shown, and the case where the supply pipe 41 and the injection nozzle 42 are one each is shown, but the case where different substances are used for both. Are provided with a temperature adjusting liquid and a cleaning liquid.

  The drive means 5 is connected to the upper end of a catalyst platen mounting portion 72 of the relative motion means 7 described later, and extends to the periphery of the chamber 6 in a direction parallel to the main surface M1 of the substrate M placed on the support portion 21. An arm portion 51, an end portion that extends to the periphery of the chamber 6 of the arm portion 51, a shaft portion 52 that extends in a direction perpendicular to the main surface M 1 of the substrate M placed on the support portion 21, and the shaft portion 52 The base part 53 which supports a lower end and the guide 54 which is arrange | positioned around the chamber 6 and defines the movement path | route of the base part 53 are provided. The arm part 51 can move in the longitudinal direction thereof (see double arrow C in FIGS. 2 and 3). The shaft part 52 can move the arm part 51 up and down by moving in the longitudinal direction (see a double-headed arrow D in FIG. 2). The base portion 53 can turn the arm portion 51 by rotating a predetermined angle about an axis in a direction perpendicular to the main surface M1 of the substrate M placed on the support portion 21 (FIG. 2). , 3 (see double arrow E). The guide 54 is disposed in a direction (first direction and second direction) parallel to two adjacent sides of the substrate M placed on the support portion 21, and forms an L-shaped movement path of the base portion 53. . The base portion 53 moves along the guide 54 in the first direction, thereby moving the arm portion 51 in the first direction (see the double arrow F in FIG. 3), and the guide 54 in the second direction. Can be moved in the second direction (see double arrow G in FIG. 3). By such movement of the arm portion 51, the catalyst surface plate 32 can be disposed at a predetermined position on the main surface M1 of the substrate M placed on the support portion 21.

  The substrate processing apparatus 1 includes a relative motion unit 7 that relatively moves the processing reference surface 33 and the main surface M1. The relative motion means 7 includes a shaft portion 71 that supports the flat surface portion 22 and extends to the outside of the chamber 6 through the opening portion 61, and a rotation drive means (not shown) that rotates the shaft portion 71. . The shaft portion 71 extends in a direction perpendicular to the main surface M1 of the substrate M placed on the support portion 21, and the main portion of the substrate M placed on the support portion 21 by rotation driving means (not shown). It can be rotated about an axis in a direction perpendicular to the surface M1 (see arrow A in FIG. 2). The center of the flat surface portion 22 and the center of the substrate M placed on the support portion 21 are positioned in the extending direction of the rotation center of the shaft portion 71. By rotating the shaft portion 71, the flat surface portion 22 supported by the shaft portion 71 rotates around the center thereof, and the substrate M placed on the support portion 21 fixed to the flat surface portion 22. Rotates around the center of rotation. Further, the relative motion means 7 includes a catalyst surface plate mounting portion 72 to which the catalyst surface plate 32 is mounted, and a rotation drive means (not shown) provided on the arm portion 51 of the drive means 5. The catalyst surface plate mounting portion 72 can be rotated by a rotation driving means (not shown) around an axis in a direction perpendicular to the main surface M1 of the substrate M placed on the support portion 21 (FIG. 2). , 3 (see arrow B).

  The substrate processing apparatus 1 includes load control means 8 that controls a load (processing pressure) applied to the substrate M. The load control means 8 is provided in the catalyst surface plate mounting portion 72, measures an air cylinder 81 that applies a load to the catalyst surface plate 32, and a load applied to the catalyst surface plate 32 by the air cylinder 81, and applies a predetermined load. A load cell 82 is provided for controlling the load applied to the catalyst platen 32 by the air cylinder 81 by turning on and off the air valve so as not to exceed. When processing by catalyst reference etching is performed, the load (processing pressure) applied to the substrate M is controlled by the load control means 8.

  As a control method for securing the machining allowance as set, for example, various local processing conditions (processing pressure, rotational speed (catalyst platen, substrate), processing fluid, Flow rate), machining time and machining allowance are determined, the machining condition and machining time to be the desired machining allowance are determined, and the machining allowance is controlled by controlling the machining time. it can. The method is not limited to this, and various methods may be selected as long as the machining allowance can be ensured as set.

In the case of performing processing by catalyst-based etching using the substrate processing apparatus shown in FIGS. 2 and 3, first, the substrate M is placed and fixed on the support portion 21 with the upper surface M1 used as the main surface facing upward. .
Thereafter, the arm part 51 moves in the longitudinal direction (double arrow C), the arm part 51 pivots (double arrow E), the arm part 51 moves in the first direction (double arrow F), and the arm part 51 moves in the second direction ( By the double arrow G), the processing reference surface 33 of the substrate surface creation means 3 is disposed so as to face the upper surface M1 of the substrate M.

Thereafter, by rotating the shaft portion 71 and the catalyst surface plate mounting portion 72 at a predetermined rotation speed, the temperature adjustment liquid is supplied from the injection nozzle 42 to the upper surface M1 while rotating the processing reference surface 33 and the upper surface M1 at a predetermined rotation speed. The temperature of the upper surface M1 of the substrate M is controlled so as to become a desired temperature, and the processing fluid is supplied from the processing fluid supply hole 91 onto the upper surface M1, and between the upper surface M1 and the processing reference surface 33. A processing fluid is interposed between the two. Since the processing fluid and the temperature adjusting liquid are mixed together, it is desirable that they are the same substance. By supplying the temperature adjusting liquid by means different from the processing fluid, CARE processing can be performed at a desired temperature with high uniformity. In this state, the processing reference surface 33 is brought into contact with or brought close to the upper surface M1 of the substrate M by the vertical movement of the arm portion 51 (double arrow D). At that time, the load applied to the substrate M is controlled to a predetermined value by the load control means 8.
Thereafter, when the predetermined machining allowance is reached, the supply of the processing fluid and the rotation of the catalyst surface plate mounting portion 72 are stopped. On the other hand, the supply of the cleaning liquid that also serves as the temperature adjustment liquid continues. Then, the machining reference surface 33 is separated from the upper surface M1 by a predetermined distance by the vertical movement of the arm portion 51 (double arrow D). Washing is performed by rotating the shaft 71 while supplying the cleaning liquid for a certain time, and then the cleaning liquid is stopped and spin drying is performed by rotating the shaft 71. Thereafter, the substrate M is taken out.
The mask blank substrate M is manufactured through the substrate preparation process and the substrate processing process.

  Regarding the temperature of the cleaning liquid, it is preferable that the temperature is initially lower than room temperature, and then the temperature is changed to finally reach room temperature. This is because the substrate processing operation becomes easier when the temperature of the substrate M is finally set to room temperature. This temperature change may be changed stepwise or continuously.

  In this embodiment, the method of uniformly controlling the temperature of the upper surface M1 of the substrate M with the temperature adjusting liquid supplied from the injection nozzle 42 has been described. May be performed. The above-described method using the temperature adjusting liquid is characterized in that the temperature adjusting liquid also serves as a cleaning liquid, so that the mechanism of the apparatus can be simplified, heat conduction is superior to cooling by the environmental temperature, and temperature control efficiency below room temperature is high. .

In this embodiment, the present invention is applied to a substrate processing apparatus of a type in which the processing reference surface 33 of the substrate surface creation means 3 is pressed onto the main surface M1 of the substrate M. However, the processing standard of the substrate surface creation means is described above. The present invention can also be applied to a substrate processing apparatus of a type in which the main surface of the substrate is pressed onto the surface.
In this embodiment, the present invention is applied to a substrate processing apparatus that processes one side of a substrate. However, the present invention can also be applied to a substrate processing apparatus that processes both surfaces of a substrate simultaneously. In this case, a carrier that is a member that holds the side surface of the substrate is used as the substrate support means.
In this embodiment, the present invention is applied to a substrate processing apparatus of the type in which the processing fluid supply means is provided in the substrate surface creation means and the processing fluid is supplied from the processing fluid supply means. The present invention can also be applied to the case where the processing fluid is supplied toward the main surface M1, or the case where the processing fluid supply means is provided in the substrate support means and the processing fluid is supplied from the substrate support means. Further, the present invention can also be applied to a case where processing fluid is stored in a chamber and processing by catalyst-based etching is performed in a state where the substrate surface creation means and the substrate support means are placed in the processing fluid.

In this embodiment, the present invention is applied to a substrate processing apparatus of a type in which both the processing reference surface 33 and the main surface M1 are rotated to rotate the processing reference surface 33 and the main surface M1. The present invention can also be applied to a substrate processing apparatus that moves the processing reference surface 33 and the main surface M1 relative to each other by a method other than the above.
Further, in this embodiment, the present invention is applied to a substrate type substrate processing apparatus that processes substrates one by one, but the present invention is also applied to a batch type substrate processing apparatus that processes a plurality of substrates simultaneously. it can. In addition, here, the case where the entire main surface of the substrate is processed is shown, but if necessary, only local processing for processing only a predetermined local portion may be performed, or these processing may be used in combination. Good.

Embodiment 2. FIG.
In Embodiment 2, a method for manufacturing a substrate with a multilayer reflective film will be described.

  In the second embodiment, high refractive index layers and low refractive index layers are alternately laminated on the main surface M1 of the mask blank substrate M manufactured by the method described in the substrate manufacturing method of the first embodiment. A multilayer reflective film is formed to produce a substrate with a multilayer reflective film, or a protective film is further formed on the multilayer reflective film to produce a substrate with a multilayer reflective film.

  According to the method for manufacturing a substrate with a multilayer reflective film according to the second embodiment, a substrate with a multilayer reflective film is manufactured using the substrate M obtained by the method for manufacturing a substrate according to the first embodiment. Can be prevented, and a substrate with a multilayer reflective film having desired characteristics can be manufactured. That is, it is possible to manufacture a substrate with a multilayer reflective film having few defects on the surface of the multilayer film and high surface smoothness and flatness.

  In the case of a substrate with a multilayer film for EUV lithography, it is necessary to pay attention to unevenness due to pits and bumps on the substrate surface and phase defects due to defects in the multilayer film. The inspection sensitivity of the phase defect is higher when the inspection is performed at the stage after the multilayer film is formed than at the substrate stage. At this time, if the surface of the substrate is rough and the surface smoothness is low, the inspection sensitivity is deteriorated due to background noise during phase defect inspection even in the inspection after the multilayer film is formed. According to the embodiment of the present invention, sufficient surface smoothness can be obtained including the surface of the multilayer film in addition to the substrate surface, so that sufficient phase defect inspection sensitivity is obtained, and the multilayer reflection film having high phase defect management quality. An attached substrate can be manufactured.

Embodiment 3 FIG.
In Embodiment 3, a mask blank manufacturing method will be described.

  In the third embodiment, a light shielding film as a transfer pattern thin film is formed on the main surface M1 of the mask blank substrate M manufactured by the method described in the substrate manufacturing method of the first embodiment to form a binary mask blank. Or a halftone phase shift mask blank by forming a translucent film as a transfer pattern thin film, or a halftone by sequentially forming a translucent film and a light-shielding film as a transfer pattern thin film A mold phase shift mask blank is manufactured.

  In the third embodiment, an absorber film as a transfer pattern thin film is formed on the protective film of the multilayer reflective film-coated substrate manufactured by the method described in the method of manufacturing the multilayer reflective film-coated substrate of the second embodiment. Alternatively, a protective film and an absorber film as a transfer pattern thin film are formed on the multilayer reflective film of the substrate with the multilayer reflective film, and a back conductive film is formed on the back surface on which the multilayer reflective film is not formed. A mold mask blank is manufactured.

  According to the third embodiment, the mask blank substrate M obtained by the substrate manufacturing method of the first embodiment or the multilayer reflective film-coated substrate obtained by the method of manufacturing the multilayer reflective film-coated substrate of the second embodiment. Since the mask blank is manufactured using, deterioration of characteristics due to substrate factors can be prevented, and a mask blank having desired characteristics can be manufactured.

Embodiment 4 FIG.
In the fourth embodiment, a method for manufacturing a transfer mask will be described.

  In the fourth embodiment, an exposure / development process is performed on the transfer pattern thin film of the binary mask blank, phase shift mask blank, or reflective mask blank manufactured by the method described in the mask blank manufacturing method of the third embodiment. To form a resist pattern. Using this resist pattern as a mask, the transfer pattern thin film is etched to form a transfer pattern to manufacture a transfer mask.

  According to the fourth embodiment, since the transfer mask is manufactured using the mask blank obtained by the mask blank manufacturing method of the third embodiment, it is possible to prevent the deterioration of the characteristics due to the substrate factor. A mask blank having the following characteristics can be manufactured.

  Hereinafter, based on an Example, this invention is demonstrated more concretely.

Example 1.
A. Production of glass substrate Substrate Preparation Step A low thermal expansion glass substrate, which is a 6025 size (152 mm × 152 mm × 6.35 mm) SiO ₂ —TiO ₂ glass substrate whose main surface and back surface were polished, was prepared. As is clear from the material composition, the surface of the glass substrate is made of an oxide. The SiO ₂ —TiO ₂ glass substrate is obtained through the following rough polishing process, precision polishing process, ultra-precision polishing process, local processing process, and touch polishing process.

(1) Rough polishing process Step 10 glass substrates that have undergone end chamfering and grinding were set in a double-side polishing apparatus, and rough polishing was performed under the following polishing conditions. A set of 10 sheets was performed twice, and a total of 20 glass substrates were roughly polished. The processing load and polishing time were adjusted as appropriate.
Polishing slurry: Aqueous solution containing cerium oxide (average particle size 2 to 3 μm) Polishing pad: Hard polisher (urethane pad)
After the rough polishing, in order to remove the abrasive grains adhering to the glass substrate, the glass substrate was immersed in a cleaning tank and cleaned by applying ultrasonic waves.

(2) Precision polishing process step Ten glass substrates after rough polishing were set in a double-side polishing apparatus, and precision polishing was performed under the following polishing conditions. A 10-sheet set was performed twice, and a total of 20 glass substrates were precisely polished. The processing load and polishing time were adjusted as appropriate.
Polishing slurry: Aqueous solution containing cerium oxide (average particle size 1 μm) Polishing pad: Soft polisher (suede type)
After the precision polishing, in order to remove abrasive grains adhering to the glass substrate, the glass substrate was immersed in a cleaning tank and cleaned by applying ultrasonic waves.

(3) Ultra-precision polishing process Step 10 glass substrates that had been subjected to precision polishing were again set in a double-side polishing apparatus, and ultra-precision polishing was performed under the following polishing conditions. A set of 10 sheets was performed twice and a total of 20 glass substrates were subjected to ultra-precision polishing. The processing load and polishing time were adjusted as appropriate.
Polishing slurry: alkaline aqueous solution (pH 10.2) containing colloidal silica
(Colloidal silica content 50wt%)
Polishing pad: Super soft polisher (suede type)
After ultra-precision polishing, the glass substrate was immersed in a cleaning tank containing an alkali cleaning solution of sodium hydroxide and cleaned by applying ultrasonic waves.

(4) Local processing step The flatness of the main surface and the back surface of the glass substrate after the rough polishing processing step, the precision polishing processing step, and the ultraprecision polishing processing step was measured using a flatness measuring device (UltraFlat200 manufactured by Tropel). . The flatness measurement was performed at a point of 1024 × 1024 with respect to an area of 148 mm × 148 mm excluding the peripheral area of the glass substrate. The measurement results of the flatness of the main surface and the back surface of the glass substrate were stored in a computer as height information (uneven shape information) with respect to the virtual absolute plane for each measurement point. The virtual absolute plane is a plane having a minimum value when the distance from the virtual absolute plane to the substrate surface is squared with respect to the entire flatness measurement region.
After that, the obtained uneven shape information was compared with the standard values of the flatness of the main surface and the back surface required for the glass substrate, and the difference was calculated by a computer for each predetermined region of the main surface and the back surface of the glass substrate. . This difference becomes a necessary removal amount (processing allowance) of each predetermined region in local surface processing.

Then, the processing conditions of the local surface processing according to the required removal amount were set for every predetermined area | region of the main surface and back surface of a glass substrate. The setting method is as follows. Using a dummy substrate in advance, the dummy substrate is processed at a certain point (spot) without moving the substrate for a certain period of time in the same manner as in actual processing, and the shape thereof is measured with a flatness measuring device (UltraFlat 200 manufactured by Tropel). Measurement was performed, and the processing volume at the spot per unit time was calculated. Then, the scanning speed for raster scanning of the glass substrate was determined according to the processing volume at the spot per unit time and the necessary removal amount of each predetermined area calculated as described above.
Then, the main surface and the back surface of the glass substrate were locally surface-treated by a magnet viscoelastic fluid polishing (MRF) using a substrate finishing device according to the processing conditions set for each predetermined region. At this time, a magnetic polishing slurry containing cerium oxide polishing particles was used.

  Thereafter, the glass substrate was immersed in a cleaning tank containing an aqueous hydrochloric acid solution having a concentration of about 10% (temperature: about 25 ° C.) for about 10 minutes, followed by rinsing with pure water and drying with isopropyl alcohol (IPA).

(5) Touch polishing process In order to improve the smoothness of the main surface and back surface of the glass substrate that has been roughened by the local processing process, the main surface and back surface of the glass substrate are only minute amounts by low-load mechanical polishing using a polishing slurry. Polished. This polishing is performed by setting a glass substrate held by a carrier between upper and lower polishing surface plates to which a polishing pad larger than the size of the substrate is attached, and containing a colloidal silica abrasive grain (average particle diameter of 50 nm). The glass substrate was revolved while rotating in the upper and lower polishing surface plates while feeding.
Thereafter, the glass substrate was immersed in an alkali cleaning solution of sodium hydroxide and cleaned by applying ultrasonic waves.

2. Substrate Processing Step Next, using the substrate processing apparatus shown in FIGS. 2 and 3, the main surface of the glass substrate after the touch polishing step was processed by catalyst-based etching. This substrate processing apparatus was installed in a clean room, and the room temperature in the clean room was 23 ° C. Therefore, the normal temperature in this case is 23 ° C.

In this embodiment, a disk-shaped surface plate 323 made of stainless steel (SUS), a fluorine rubber pad 322 formed on the entire surface of the surface plate 323 so as to cover the surface plate 323, and a side facing the glass substrate. A catalyst surface plate 32 made of a catalyst material 321 made of a platinum thin film formed by a sputtering method using a platinum (Pt) target in an argon (Ar) gas over the entire surface of the fluorine rubber pad is used. The surface was used as the processing reference surface 33. Here, the diameter of the catalyst platen 32 is 100 mm, and the film thickness of the Pt thin film formed on the fluorine rubber pad 322 is 100 nm.
Processing and cleaning conditions are as follows.
Processing fluid: Pure water Substrate temperature adjustment and cleaning liquid: Pure water Clean room room temperature: 23 ° C
Temperature of processing fluid and substrate temperature adjusting liquid: 15 ° C
Cleaning liquid temperature: 23 ° C
Number of rotations of the shaft portion 71 (number of rotations of the glass substrate): 10.3 rotations / minute Number of rotations of the catalyst surface plate mounting portion 72 (number of rotations of the catalyst surface plate 32): 10 rotations / minute Processing pressure: 150 hPa
Processing allowance: 10nm

First, the glass substrate M was placed and fixed on the support portion 31 with the main surface facing upward.
Thereafter, the longitudinal movement of the arm 51 (double arrow C), the swing movement of the arm 51 (double arrow E), the first movement of the arm 51 (double arrow F), and the second movement of the arm 51 ( With the double arrow G), the catalyst surface plate 32 was disposed in a state where the processing reference surface 33 of the catalyst surface plate 32 was disposed opposite to the main surface M1 of the glass substrate. The arrangement position of the catalyst surface plate 32 is such that when the glass substrate M and the catalyst surface plate 32 are rotated, the processing reference surface 33 of the catalyst surface plate 32 can contact or approach the entire main surface of the glass substrate. Position.

  Thereafter, the glass substrate is rotated at a rotation speed of 10.3 rotations / minute and the catalyst surface plate 32 is rotated at a rotation speed of 10 rotations / minute. Here, the glass substrate M and the catalyst platen 32 are rotated so that the rotation direction of the glass substrate M and the rotation direction of the catalyst platen 32 are opposite to each other. Thereby, a peripheral speed difference can be taken between them, and the processing efficiency by catalyst reference | standard etching can be improved. Further, the rotational speeds of the two are set to be slightly different. Thereby, the processing reference surface 33 of the catalyst surface plate 32 can be moved relative to the main surface M1 of the glass substrate so as to draw different trajectories, and the processing efficiency by the catalyst reference etching can be increased.

While rotating the glass substrate M and the catalyst surface plate 32, a temperature adjusting liquid for adjusting the substrate temperature is sprayed from the injection nozzle 42 onto the substrate M, and the processing fluid is supplied from the processing fluid supply hole 91 to the substrate surface M1. . The temperature adjusting liquid and the processing fluid are pure water at 15 ° C. The room temperature of the clean room, which is the ambient temperature at this time, is 23 ° C., and the temperature adjusting liquid and the processing fluid are set to a temperature below room temperature. In this way, 15 ° C. pure water is supplied onto the main surface M 1 of the glass substrate M to uniformly increase the temperature of the main surface of the glass substrate, and 15 ° C. pure water is interposed between the processing reference surface 33. I let you. In this state, the processing reference surface 33 of the catalyst surface plate 32 was brought into contact with or brought close to the surface of the glass substrate M by the vertical movement of the arm portion 51 (double arrow D). At that time, the load (processing pressure) applied to the glass substrate M was controlled to 150 hPa.
Thereafter, when the machining allowance reaches 10 nm, the supply of the processing fluid at 15 ° C. is stopped, and the catalyst surface plate 32 is moved from the main surface M1 of the glass substrate M by the vertical movement of the arm portion 51 (double arrow D). Separated by a predetermined distance. The temperature adjustment liquid was continuously switched to a cleaning liquid that was 23 ° C. pure water, and the cleaning water was continuously supplied from the spray nozzle 42. During this time, the glass substrate M and the catalyst platen 32 continued to rotate, and spin cleaning with pure water at room temperature was performed. Thereafter, the supply of washing water was stopped and spin drying was performed. Thereafter, the glass substrate M at room temperature was removed from the support portion 21 to produce a glass substrate.

3. Evaluation The surface roughness of the main surface of the glass substrate M before and after processing by the catalyst-based etching was measured using an atomic force microscope (AFM) for a 1 μm × 1 μm region at the center of the substrate.
The surface roughness of the main surface before processing was 0.157 nm in terms of root mean square roughness (Rms).
The surface roughness of the main surface after processing was 0.044 nm in terms of root mean square roughness (Rms), which was well below the required value of 0.08 nm.

A defect inspection apparatus (mask / blank defect inspection apparatus manufactured by KLA-Tencor Co., Ltd.) is used for a defect inspection of the main surface M1 of the glass substrate M after processing by catalyst-based etching, for a 132 mm × 132 mm area excluding the peripheral area of the substrate (Teron 610). The defect inspection was performed with a sensitivity capable of detecting a 21.5 nm size defect in terms of SEVD (Sphere Equivalent Volume Diameter). SEVD is the length of the diameter when the defect is assumed to be hemispherical.
The number of concave defects on the main surface after processing was 7.
Further, when 20 glass substrates were produced by the method of Example 1, the total number and the surface roughness were as good as 0.046 nm or less in root mean square roughness (Rms). The flatness was 41 nm. The flatness was measured using a flatness measuring device (UltraFlat 200 manufactured by Tropel). The flatness measurement was performed at a point of 1024 × 1024 with respect to an area of 148 mm × 148 mm excluding the peripheral area of the glass substrate.
By the method of Example 1, a glass substrate having a main surface with low defects and high smoothness and flatness was stably obtained.

B. Next, a high refractive index layer (thickness: 4.2 nm) made of a silicon film (Si) is formed on the main surface M1 of the glass substrate M thus produced by ion beam sputtering. ) And a low-refractive index layer (2.8 nm) made of a molybdenum film (Mo), and a high-refractive index layer and a low-refractive index layer as one pair, and 40 pairs are laminated to form a multilayer reflective film (film thickness) 280 nm).
Thereafter, a protective film (thickness 2.5 nm) made of ruthenium (Ru) was formed on the multilayer reflective film by ion beam sputtering. The incident angles of the sputtered particles of Mo, Si, and Ru with respect to the normal of the main surface of the glass substrate in ion beam sputtering were set to 50 degrees for Mo, 45 degrees for Si, and 40 degrees for Ru, respectively.
In this way, a substrate with a multilayer reflective film was produced.

About the obtained board | substrate with a multilayer reflective film, the reflectance of EUV light (wavelength 13.5nm) was measured with the EUV reflectance measuring apparatus.
Due to the high smoothness of the main surface of the glass substrate, the surface of the protective film was also kept smooth, and the reflectance was as high as 64%.
The defect inspection of the protective film surface of the obtained multilayer reflective film-coated substrate was performed in the same manner as the defect inspection of the glass substrate.
The number of detected defects on the surface of the protective film was 10 with a sensitivity capable of detecting 21.5 nm-sized concave defects in terms of SEVD. The phase defect inspection was also performed. However, because of the high smoothness, the background noise at the time of inspection was small, and the phase defect inspection with high sensitivity could be performed.
By the method of Example 1, a multilayer reflective film-coated substrate having a low-defect and high-smooth protective film surface was obtained.

C. Production of Reflective Mask Blank Next, a tantalum boride (TaB) target is used on the protective film of the multilayer reflective film substrate thus produced, and argon (Ar) gas and nitrogen (N ₂ ) gas are used. Reactive sputtering is performed in a mixed gas atmosphere to form a lower absorber layer (film thickness 50 nm) made of tantalum boron nitride (TaBN), and tantalum boride (TaB) is further formed on the lower absorber film. Using a target, reactive sputtering is performed in a mixed gas atmosphere of argon (Ar) gas and oxygen (O ₂ ) gas to form an upper absorber layer (thickness 20 nm) made of tantalum boron oxide (TaBO). As a result, a layer absorber film (film thickness 70 nm) composed of a lower absorber layer and an upper absorber layer was formed.
Thereafter, a reaction in a mixed gas atmosphere of argon (Ar) gas and nitrogen (N ₂ ) gas using a chromium (Cr) target on the back surface of the substrate with the multilayer reflective film on which the multilayer reflective film is not formed. A back conductive film (thickness 20 nm) made of chromium nitride (CrN) was formed by reactive sputtering.
In this way, a reflective mask blank for EUV exposure, in which a surface state with low defects and high smoothness was maintained, was produced.

D. Production of Reflective Mask Next, a chemically amplified resist for electron beam drawing (exposure) is applied onto the absorber film of the thus produced reflective mask blank by a spin coating method, and heating and cooling steps are performed. Then, a resist film having a thickness of 150 nm was formed.
Thereafter, a desired pattern was drawn on the formed resist film using an electron beam drawing apparatus, and then developed with a predetermined developer to form a resist pattern.
Thereafter, using this resist pattern as a mask, the absorber film was dry-etched to form an absorber film pattern on the protective film. As a dry etching gas, chlorine (Cl ₂ ) gas was used.
Thereafter, the remaining resist pattern was peeled off and washed.
In this way, a reflective mask for EUV exposure that maintains a surface state with low defects and high smoothness was produced.

Example 2
A. Production of Glass Substrate In this example, a synthetic quartz glass substrate of 6025 size (152 mm × 152 mm × 6.35 mm) whose upper and lower surfaces were polished was prepared. As is clear from the material composition, the surface of the synthetic quartz glass substrate is an oxide. The synthetic quartz glass substrate is obtained through the above-described rough polishing process, precision polishing process, and ultraprecision polishing process.
Moreover, the temperature of the pure water which is a process fluid and a substrate temperature adjustment liquid was 18 degreeC. Otherwise, a glass substrate was produced in the same manner as in Example 1. That is, a glass substrate having a surface made of an oxide was manufactured by CARE processing in which the temperature of pure water as the processing fluid and the substrate temperature adjusting liquid was 18 ° C. Therefore, the processing and cleaning conditions are as follows.
Processing fluid: Pure water Substrate temperature adjustment and cleaning liquid: Pure water Clean room room temperature: 23 ° C
Temperature of processing fluid and substrate temperature adjusting liquid: 18 ° C
Cleaning liquid temperature: 23 ° C
Number of rotations of the shaft portion 71 (number of rotations of the glass substrate): 10.3 rotations / minute Number of rotations of the catalyst surface plate mounting portion 72 (number of rotations of the catalyst surface plate 32): 10 rotations / minute Processing pressure: 150 hPa
Processing allowance: 10nm

In the same manner as in Example 1, the surface roughness of the upper surface used as the main surface of the glass substrate before and after processing by CARE processing was measured.
The surface roughness of the main surface before processing was 0.127 nm in terms of root mean square roughness (Rms).
The surface roughness of the main surface after processing was 0.046 nm in terms of root mean square roughness (Rms), which was well below the required value of 0.08 nm. The surface roughness of the upper surface was improved from 0.127 nm to 0.046 nm in terms of root mean square roughness (Rms) by catalyst-based etching in which the temperature of pure water as a processing fluid was 18 ° C.
Further, in the same manner as in Example 1, a defect inspection of the upper surface of the glass substrate after processing by CARE processing was performed.
The number of concave defects on the main surface after processing was nine.
Further, when 20 glass substrates were produced by the method of Example 2, the total number and the surface roughness were good, the root mean square roughness (Rms) being 0.050 nm or less, and the number of concave defects was 10 or less. Met. The surface flatness was 43 nm.
By the method of Example 2, a glass substrate having a high smoothness, high flatness, and a low-defect main surface was stably obtained.

B. Production of Halftone Phase Shift Mask Blank Next, a molybdenum silicide (MoSi) target is used on the upper surface of the glass substrate thus produced, and argon (Ar), nitrogen (N ₂ ), and oxygen (O ₂ ) reactive sputtering was performed in a mixed gas atmosphere to form a light semi-transmissive film (film thickness: 88 nm) made of molybdenum silicide oxynitride (MoSiON). The film composition of the light translucent film analyzed by Rutherford backscattering analysis was Mo: 5 atomic%, Si: 30 atomic%, O: 39 atomic%, and N: 26 atomic%. The transmittance of the light semi-transmissive film with respect to the exposure light was 6%, and the phase difference caused by the exposure light passing through the light semi-transmissive film was 180 degrees.

Then, using a chromium (Cr) target on the light semi-transmissive film, reactive sputtering is performed in a mixed gas atmosphere of argon (Ar), carbon dioxide (CO ₂ ), nitrogen (N ₂ ), and helium (He). To form a chromium oxycarbonitride (CrOCN) layer (thickness 30 nm), and further, using a chromium (Cr) target, a mixed gas of argon (Ar) and nitrogen (N ₂ ) Reactive sputtering is performed in an atmosphere to form a chromium nitride (CrN) layer (film thickness: 4 nm), and a light-shielding layer comprising a laminate of a chromium oxycarbonitride (CrOCN) layer and a chromium nitride (CrN) layer Formed. Further, a chromium (Cr) target is used on the light shielding layer, and reactive sputtering is performed in a mixed gas atmosphere of argon (Ar), carbon dioxide (CO ₂ ), nitrogen (N ₂ ), and helium (He). Then, a surface antireflection layer (film thickness: 14 nm) made of chromium oxycarbonitride (CrOCN) was formed. In this way, a light shielding film composed of the light shielding layer and the surface antireflection layer was formed.
In this way, a halftone phase shift mask blank for ArF excimer laser exposure was produced that maintained a surface state with low defects and high smoothness and flatness.

C. Production of halftone phase shift mask Next, a chemical amplification resist for electron beam drawing (exposure) is applied onto the light-shielding film of the halftone phase shift mask blank produced in this way by a spin coating method. Through a heating and cooling process, a resist film having a thickness of 150 nm was formed.
Thereafter, a desired pattern was drawn on the formed resist film using an electron beam drawing apparatus, and then developed with a predetermined developer to form a resist pattern.
Thereafter, using this resist pattern as a mask, the light shielding film was dry etched to form a light shielding film pattern on the light semi-transmissive film. As a dry etching gas, a mixed gas of chlorine (Cl ₂ ) and oxygen (O ₂ ) was used.

Thereafter, using the resist pattern and the light shielding film pattern as a mask, the light semi-transmissive film was dry-etched to form a light semi-transmissive film pattern. As the dry etching gas, a mixed gas of sulfur hexafluoride (SF ₆ ) and helium (He) was used.
Thereafter, the remaining resist pattern is peeled off, a resist film is applied again, pattern exposure is performed to remove an unnecessary light-shielding film pattern in the transfer region, and then the resist film is developed to form a resist pattern. .
Thereafter, wet etching was performed to remove an unnecessary light shielding film pattern.
Thereafter, the remaining resist pattern was peeled off and washed.
In this way, a halftone phase shift mask for ArF excimer laser exposure, which maintains a surface state with low defects and high smoothness, was produced.

  In this embodiment, the present invention is applied to a halftone phase shift mask and a phase shift mask blank having a light semi-transmissive film made of molybdenum silicide oxynitride (MoSiON). However, molybdenum silicide nitride (MoSiN) is used. The present invention can also be applied to a halftone phase shift mask or a phase shift mask blank having a light semi-transmissive film made of The present invention is not limited to halftone phase shift masks and phase shift mask blanks having a single-layer light semi-transmissive film, but also to halftone phase shift masks and phase shift mask blanks having a multi-layered light semi-transmissive film. The invention can be applied. Further, the present invention can be applied not only to a halftone phase shift mask and a phase shift mask blank having a multi-layered light shielding film, but also to a halftone phase shift mask and a phase shift mask blank having a single-layer light shielding film. . Further, the present invention can be applied not only to the halftone phase shift mask blank and the phase shift mask blank but also to a Levenson type phase shift mask blank, a phase shift mask blank, a chromeless type phase shift mask blank, and a phase shift mask blank.

  In this example, the present invention was applied to the case where the main surface of the glass substrate obtained through the rough polishing process, the precision polishing process, and the ultraprecision polishing process was subjected to processing by catalyst-based etching. However, the present invention can also be applied to the case where the main surface of the glass substrate obtained through the local processing step and the touch polishing step performed in Example 1 is processed by catalyst-based etching.

Comparative example.
In this comparative example, in the CARE processing in Example 1, the temperature of the processing fluid made of pure water was changed from 15 ° C. to 23 ° C. of room temperature, and other than that, from the substrate material and its pre-treatment to the production of the reflective mask A glass substrate, a substrate with a multilayer reflective film, a reflective mask blank, and a reflective mask were produced in the same manner as in Example 1. The substrate temperature adjusting liquid is not used. Therefore, the processing and cleaning conditions are as follows.
Processing fluid: Pure water Cleaning fluid: Pure water Clean room room temperature: 23 ° C
Processing fluid temperature: 23 ° C
Cleaning liquid temperature: 23 ° C
Number of rotations of the shaft portion 71 (number of rotations of the glass substrate): 10.3 rotations / minute Number of rotations of the catalyst surface plate mounting portion 72 (number of rotations of the catalyst surface plate 32): 10 rotations / minute Processing pressure: 150 hPa
Processing allowance: 10nm

In the same manner as in Example 1, the surface roughness of the upper surface used as the main surface of the glass substrate before and after processing by CARE processing was measured.
The surface roughness of the main surface before processing was 0.157 nm in terms of root mean square roughness (Rms).
The surface roughness of the main surface after processing was 0.05 nm in terms of root mean square roughness (Rms), which was well below the required value of 0.08 nm. The surface roughness of the upper surface was improved from 0.157 nm to 0.05 nm in terms of root mean square roughness (Rms) by CARE processing in which the temperature of pure water as a processing fluid was 23 ° C. On the other hand, the flatness was 51 nm.
Further, in the same manner as in Example 1, a defect inspection of the upper surface of the glass substrate after processing by CARE processing was performed.
The number of concave defects on the main surface after processing was 217.
Further, when 20 glass substrates were produced by this method, the total number and the surface roughness were as good as 0.056 nm or less in root mean square roughness (Rms), but the number of defects was 200 to 248. there were.
In the method of the comparative example, although a high smoothness was obtained, a glass substrate having many defects on the main surface was produced. The flatness was also lower than that in Example 1.

In the same manner as in Example 1, the reflectance of EUV light (wavelength: 13.5 nm) was measured for the obtained substrate with a multilayer reflective film.
Due to the high smoothness of the upper surface of the glass substrate, the surface of the protective film was also kept smooth, and the reflectance was as high as 64%.
Moreover, the defect inspection of the protective film surface of the obtained board | substrate with a multilayer reflective film was performed similarly to Example 1. FIG.
The number of detected defects on the surface of the protective film was 385 with a sensitivity capable of detecting 21.5 nm-sized concave defects in terms of SEVD.
In the method of the comparative example, although a high smoothness was obtained, a substrate with a multilayer reflective film having many defects was produced.
In the method of the comparative example, although a high smoothness was obtained, a reflective mask blank and a reflective mask for EUV exposure having a surface state with many defects were produced.

  In the above-described embodiment, the present invention is applied to the case where the main surface of the reflective mask blank substrate or the phase shift mask blank substrate is processed by catalyst-based etching. However, for binary mask blanks and nanoimprints. The present invention can also be applied to a case where the main surface of the mask blank is processed by catalyst-based etching.

DESCRIPTION OF SYMBOLS 1 ... Substrate processing apparatus, 2 ... Substrate support means, 3 ... Substrate surface creation means, 4 ... Temperature adjustment liquid, cleaning liquid supply means, 5 ... Drive means, 6 ... Chamber, 7 ... Relative motion means, 8 ... Load control means, DESCRIPTION OF SYMBOLS 9 ... Processing fluid supply means, 21 ... Supporting part, 22 ... Planar part, 22a ... Accommodating part, 31 ... Catalyst surface plate part, 32 ... Catalyst surface plate (catalyst surface body part), 33 ... Processing reference plane, 41 ... Supply pipe, 42 ... injection nozzle, 51 ... arm part, 52 ... shaft part, 53 ... base part, 54 ... guide, 61 ... opening, 62 ... discharge port, 63 ... bottom part, 71 ... shaft part 71, 72 ... catalyst Surface plate mounting part, 81 ... Air cylinder, 82 ... Load cell, 91 ... Processing fluid supply hole, 100 ... Processing fluid below room temperature, 101 ... Processing fluid below room temperature, 321 ... Catalyst substance (catalyst), 322 ... Base material ( Pad), 323 ... surface plate, M ... (for mask blank) substrate M1 ... main surface (upper surface), M2 ... lower surface.

Claims (8)

A substrate preparation step of preparing a mask blank substrate having a main surface made of a material containing an oxide;
The processing reference surface of the catalytic substance and the main surface are brought into contact with or close to each other, and the main surface and the processing reference surface are moved relative to each other while a processing fluid is interposed between the processing reference surface and the main surface. A step of performing catalyst-based etching of the main surface by:
In a method for manufacturing a mask blank substrate having
Wherein the processing fluid is a liquid which undergoes hydrolysis in the substrate main surface, by the temperature of the process fluid in the catalyst based etching at a temperature below room temperature, and wherein the resulting in higher viscosity of the process fluid A method for manufacturing a mask blank substrate.   2. The method for manufacturing a mask blank substrate according to claim 1, wherein at least a main surface of the substrate is cooled to a temperature lower than room temperature during the catalyst-based etching step. The catalyst reference etching includes a surface plate, a pad formed on the entire surface of the surface plate, and a processing reference surface made of the catalyst material formed on the entire surface of the pad on the side facing the substrate main surface. Is performed using a catalyst surface plate equipped with
The method for manufacturing a mask blank substrate according to claim 1, wherein the surface plate is made of a low thermal expansion material. 4. The mask blank substrate according to claim 1, wherein the processing fluid is pure water, ozone water, carbonated water, hydrogen water, an aqueous KOH solution, or an aqueous HNO ₃ solution. 5. Production method.   The method for manufacturing a mask blank substrate according to claim 2, wherein cooling of the main surface of the substrate is performed by supplying a temperature adjusting liquid having a temperature lower than room temperature to the main surface of the substrate. A method for producing a substrate with a multilayer reflective film, comprising: forming a multilayer reflective film on a main surface of the substrate produced by the method for producing a mask blank substrate according to any one of claims 1 to 5 . A multilayer reflection obtained on the main surface of a substrate obtained by the method for producing a mask blank substrate according to any one of claims 1 to 5 or obtained by the method for producing a substrate with a multilayer reflective film according to claim 6. A mask blank manufacturing method, comprising: forming a transfer pattern thin film on a multilayer reflective film of a film-coated substrate. A method for manufacturing a transfer mask, comprising: patterning a thin film for transfer pattern of a mask blank obtained by the method for manufacturing a mask blank according to claim 7 to form a transfer pattern.

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