JP6367417B2 - Manufacturing method of mask blank substrate, manufacturing method of substrate with multilayer film, manufacturing method of mask blank, manufacturing method of transfer mask, and mask blank substrate manufacturing apparatus - Google Patents

Description

  The present invention relates to a method for manufacturing a 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, a method for manufacturing a transfer mask using a mask blank, and The present invention relates to a substrate manufacturing apparatus, and in particular, a method for manufacturing a substrate with high flatness and low defect density, a method for manufacturing a reflective substrate with a multilayer film, and a method for manufacturing a mask blank using a mask blank substrate or a substrate with a multilayer reflective film The present invention relates to a method for manufacturing a transfer mask using a mask blank, and a substrate manufacturing apparatus for performing the manufacturing.

  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 flattening, smoothing, and reducing defects at a finer size for mask blank substrates 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, a defect of 30 nm class (SEVD (Sphere Equivalent Volume Diameter) of 23 nm or more and 34 nm or less) becomes a problem. 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).

  Further, in recent years, in the hard disk drive (HDD), the flying height of the recording / reading head with respect to the magnetic recording medium is further reduced as the recording capacity of the magnetic recording medium is increased. It has become. As such a head, a head mounted with a DFH (Dynamic Flying Height) mechanism is also widespread. The DFH mechanism operates so that the magnetic head thermally expands due to the heat generated by the heating element provided in the magnetic head, and the magnetic head projects slightly in the direction of the air bearing surface, thereby keeping the flying height constant. Can do. A head equipped with such a DFH mechanism has a flying height of about several nanometers, and thus a defect such as a head crash tends to occur when a magnetic recording medium is used. In order to reduce such defects, the surface of the magnetic recording medium substrate is required to have a low defect surface with high smoothness and substantially no protrusions.

  As a substrate for a magnetic recording medium, there is a metal substrate such as aluminum, but a glass substrate containing silicon that is less likely to be plastically deformed than a metal substrate and has high surface smoothness when the main surface of the substrate is mirror-polished. Are preferably used.

  Until now, various processing methods have been proposed in order to make the main surface of the mask blank substrate and the magnetic recording medium substrate have a high smoothness, a low defect, and substantially no protrusions. It has been difficult to realize a substrate having a main surface that satisfies desired characteristics.

  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 solution adsorbed on a processing reference surface formed from a catalyst material, 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 does not need to be bulk, and may be a thin film in which a metal or a transition metal is formed by sputtering or the like on the surface of a base material that is inexpensive and has good shape stability. In addition, the base material on which the catalyst material is formed may be a hard elastic material, and for example, it is described that a fluorine-based rubber can be used.

International Publication No. 2013/084934

As described in the background, for advanced mask blank substrates and the like, both a reduction in defects of 30 nm class and high smoothness with a root mean square roughness (Rms) of 0.08 nm or less are required. It has been.
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 made of silicon oxide. Substrates made of the materials they contain are the mainstream. When a substrate made of a material containing a silicon oxide on the surface is CARE processed, for example, as described in Patent Document 1, orthosilicic acid (H ₄ SiO ₄ ), metasilicic acid (H ₂ SiO ₃ ), metadisilicic acid ( It is known that silicic acid such as H ₂ SiO ₂ ) is produced. Since these silicic acids are similar in composition to the material of the substrate, it is very difficult to remove the silicic acid remaining on the substrate without affecting the surrounding substrate surface. For this reason, the conventional CARE processing of a substrate made of a material containing silicon oxide has a problem of generation of foreign matter defects due to silicic acid such as orthosilicic acid, which is a big problem for reducing defects. The present inventors paid attention to the fact that
The present invention has been made in order to solve the above-described problems, and suppresses the generation of foreign substances caused by silicic acid, particularly the generation of orthosilicate foreign substances, and has a surface having a low defect and a high smooth main surface. An object of the present invention is to provide a method for producing a substrate made of a material containing silicon oxide, a method for producing a substrate with a multilayer film, a method for producing a mask blank, a method for producing a transfer mask, and a substrate production apparatus for carrying out the production. And

  The present inventor has found that the defects due to silicic acid can be reduced while reducing the required surface roughness by adjusting the temperature of the treatment liquid. The present invention has the following configuration.

(Configuration 1)
A substrate preparing step of preparing a substrate made of a material containing at least a main surface of silicon oxide;
A processing reference surface of a catalytic substance is brought into contact with or close to the main surface, and the main surface and the processing reference surface are moved relative to each other in a state where a processing liquid 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 of manufacturing a substrate having
The process liquid is a liquid that causes hydrolysis on the main surface of the substrate, and the temperature of the process liquid during the catalyst-based etching is a temperature exceeding room temperature.
(Configuration 2)
At least the main surface of the substrate is heated to a temperature exceeding room temperature during the catalyst-based etching step.
(Configuration 3)
3. The method for manufacturing a substrate according to Configuration 1 or 2, wherein the treatment liquid is supplied by spraying on the main surface.
(Configuration 4)
After the completion of the catalyst-based etching step, the substrate main surface is cleaned with the cleaning liquid after continuously replacing the processing liquid with a cleaning liquid. Production method.
(Configuration 5)
In the cleaning step, the temperature of the cleaning liquid is adjusted according to the elapsed time so that the temperature of the cleaning liquid is higher than normal temperature at the start time and at least at normal temperature at the end time. The manufacturing method of the board | substrate of description.
(Configuration 6)
6. The substrate manufacturing method according to any one of Structures 1 to 5, wherein the treatment liquid and the cleaning liquid are the same substance.
(Configuration 7)
7. The method for manufacturing a substrate according to any one of Structures 1 to 6, wherein the treatment liquid is pure water.
(Configuration 8)
8. The method for manufacturing a substrate according to Configuration 7, wherein the temperature of the treatment liquid is in the range of 40 ° C. to 80 ° C.
(Configuration 9)
9. The method of manufacturing a substrate according to any one of configurations 1 to 8, wherein the substrate is a mask blank substrate.
(Configuration 10)
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 substrate according to Configuration 9.
(Configuration 11)
Transfer onto the main surface of the substrate obtained by the method for producing a substrate according to Configuration 9, or onto the multilayer reflective film of the substrate with a multilayer reflective film obtained by the method for producing a substrate with a multilayer reflective film according to Configuration 10. A method for manufacturing a mask blank, comprising forming a pattern thin film.
(Configuration 12)
A method for producing a transfer mask, comprising: patterning a thin film for a transfer pattern of a mask blank obtained by the method for producing a mask blank according to Configuration 11 to form a transfer pattern.
(Configuration 13)
A substrate manufacturing apparatus for manufacturing a substrate by processing the main surface of the substrate by catalyst-based etching,
Substrate support means for supporting the substrate;
A substrate surface creation means having a processing reference surface of a catalytic substance disposed opposite to the main surface of the substrate supported by the substrate support means;
Relative motion means for relatively moving the processing reference surface and the main surface in contact with or approaching each other,
A treatment liquid supply means for supplying a treatment liquid between the processing reference surface and the main surface;
A substrate manufacturing apparatus comprising temperature adjusting means for raising the temperature of the processing liquid from room temperature.
(Configuration 14)
14. The substrate manufacturing apparatus according to Configuration 13, comprising means for supplying a cleaning liquid and temperature adjusting means for adjusting the temperature of the cleaning liquid from the temperature of the processing liquid to room temperature.

  According to the present invention, by increasing the temperature of the CARE processing liquid from room temperature, silicic acid-derived components such as orthosilicic acid generated by CARE processing (hereinafter referred to as “orthosilicic acid, etc.” as appropriate) It is easily dissolved and hardly remains as a foreign substance, and it becomes possible to reduce defects. As a result of detailed examination, it was found that the required value was sufficiently satisfied with respect to the surface roughness of the substrate surface, that is, the smoothness. For this reason, it becomes possible to provide the manufacturing method of the board | substrate which the surface which has a high smooth main surface with a low defect consists of a material containing a silicon oxide.

  In addition, according to the method for manufacturing a substrate with a multilayer reflective film according to the present invention, since the substrate with the multilayer reflective film is manufactured using the substrate obtained by the above-described substrate manufacturing method, the multilayer reflective with desired characteristics is produced. 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 transfer mask manufacturing method of the present invention, a transfer mask is manufactured using the mask blank obtained by the above-described mask blank manufacturing method. Can be manufactured.

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. It is a characteristic view which shows the process liquid temperature dependence of the defect generation number and surface roughness by catalyst reference | standard etching.

  Hereinafter, a method for manufacturing a substrate according to an embodiment of the present invention, a method for manufacturing a substrate with a multilayer reflective film using the substrate, a method for manufacturing a mask blank using the substrate or the substrate with a multilayer reflective film, and the mask blank A method of manufacturing a transfer mask using the above will be described in detail with reference to 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 Embodiment 1, a substrate manufacturing method and a substrate processing apparatus will be described.

In the first embodiment, a substrate preparation step for preparing a substrate whose main surface is made of a material containing silicon oxide, and a processing reference surface of the catalytic substance is brought into contact with or close to the main surface of the substrate, so that the processing reference surface and the main surface are obtained. A substrate is manufactured by a substrate processing step in which the main surface of the substrate is processed by catalyst-based etching with a treatment liquid interposed therebetween.
Hereinafter, each process will be described in detail.

1. Substrate Preparation Step In the substrate manufacturing method, first, a substrate whose main surface is made of a material containing silicon oxide is prepared.

The substrate to be prepared includes, for example, a substrate made of a material containing silicon oxide as a whole, a substrate on which a thin film made of a material containing silicon oxide is formed on the upper surface used as the main surface, and upper and lower surfaces used as the main surface. Both are substrates on which a thin film made of a material containing silicon oxide is formed.
The substrate on which the thin film is formed may be a substrate in which a thin film made of a material containing silicon 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 silicon oxide, or silicon. The board | substrate with which the thin film which consists of a material containing a silicon oxide was formed in the upper surface and lower surface used as a main surface of the board | substrate body (base | substrate) consisting of other than the material containing an oxide may be sufficient.

Examples of the material of the substrate or substrate body made of a material containing silicon oxide include synthetic quartz glass, soda lime glass, borosilicate glass, aluminosilicate glass, SiO ₂ —TiO ₂ glass, and glass ceramics. It is done. Moreover, silicon, carbon, and a metal are mentioned as a material of the board | substrate body (base | substrate) consisting of other than the material containing a silicon oxide.
Specifically, as the silicon oxide forming the thin film, silicon oxide (SiO _x , (x> 0)) or metal silicide oxide containing metal and silicon (Me _x Si _y O _z , (Me: metal) X> 0, y> 0, and z> 0)). Such a thin film made of a material containing silicon oxide can be formed by, for example, vapor deposition, sputtering, or electroplating.
Further, the above-described silicon 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 may be a mask blank substrate or a magnetic recording medium 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. Further, the substrate material used for the transmissive 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. In addition, the substrate material used for the magnetic recording medium substrate needs to be chemically strengthened after the polishing step in order to improve impact resistance, strength and rigidity. For this reason, the substrate material used for the magnetic disk substrate is preferably, for example, a multicomponent glass such as borosilicate glass or aluminosilicate glass.

  The substrate to be prepared is preferably a substrate whose main surface has been 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. 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 the main surface is subjected to catalyst reference etching (CARE) with the processing liquid interposed between the processing reference surface and the main surface. )
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, first, a processing reference surface made of a catalyst material is disposed so as to face the main surface of the substrate. And, with the processing liquid supplied between the processing reference surface and the main surface, with the processing liquid interposed between the processing reference surface and the main surface, the processing reference surface is brought into contact with or close to the main surface, While applying a predetermined load (processing pressure) to the substrate, the processing reference surface and the main surface are moved relative to each other. When the processing reference surface and the main surface are moved relative to each other with the processing liquid interposed between the processing reference surface and the main surface, the activity generated from the molecules in the processing liquid adsorbed on the processing reference surface The seed and the main surface react and the main surface is processed. Here, this reaction is a hydrolysis reaction when the substrate surface contains silicon oxide or silicon oxide. The active species are generated only on the processing reference surface and deactivated when they are separated from the vicinity of the processing reference surface. Therefore, there is almost no reaction with the active species other than the main surface with which the processing reference surface contacts or approaches. In this way, the main surface is processed by catalyst-based etching. In the processing based on catalyst-based etching, since no abrasive is used, damage to the mask blank substrate is extremely small, and generation of new defects can be prevented.

The relative motion between the processing reference surface and the main surface is not particularly limited as long as the processing reference surface and the main surface move relative to each other. When the substrate is fixed and the processing reference surface is moved, the processing reference surface is fixed and the substrate is moved, or both the processing reference surface and the substrate are moved. When the processing reference plane moves, the movement may be a case where the machining reference plane rotates around an axis in a direction perpendicular to the main surface of the substrate or a case where the processing reference plane reciprocates in a direction parallel to the main surface of the substrate. Similarly, when the substrate moves, the movement may be when the substrate rotates about an axis perpendicular to the main surface of the substrate or when the substrate reciprocates in a direction parallel to the main surface of the substrate.
The load (processing pressure) applied to the substrate 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 of the substrate, 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 that forms the processing reference surface may be any material that generates active species that hydrolyze the substrate surface with respect to the processing liquid, and a material containing a metal element, preferably a transition metal element, is preferable. 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 can be improved. These catalyst substances are formed on a pad made of fluorine rubber or the like.

Area of the working reference plane is smaller than the area of the main surface of the substrate, for ^example, a 100mm ² ~10000mm 2. By downsizing the processing reference surface, the substrate processing apparatus can be downsized and high-precision processing can be performed reliably.
Further, the area of the processing reference plane may be larger than the area of the main surface of the substrate. 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 can be suppressed.

The treatment liquid 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 silicon oxide and induces hydrolysis. By using such a processing solution, the substrate is not dissolved by the processing solution, and unnecessary deformation of the substrate can be prevented. For example, pure water, ozone water, carbonated water, hydrogen water, low concentration alkaline aqueous solution such as KOH aqueous solution, or low concentration acidic aqueous solution such as 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 treatment liquid from the viewpoints of cost, processing characteristics, ease of handling during cleaning, and the like.

  The temperature of the processing liquid during CARE processing is set to a temperature higher than normal temperature in order to reduce defects. This is a feature of the present invention. When the temperature is raised from room temperature, the solubility of orthosilicic acid or the like in the treatment liquid is increased. Therefore, by setting the treatment liquid temperature, defects due to silicic acid due to orthosilicic acid or the like caused by precipitation or the like are reduced. 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. In many cases, chemicals such as resist and developer are also optimized for quality and quality control with 23 ° C. as a default. Therefore, although the normal temperature is often 23 ° C., it is not limited to that temperature.

  When pure water is used as a CARE processing solution, 40 to 80 ° C. is preferable for processing at atmospheric pressure, more preferably 60 to 80 ° C., and much more at 75 to 80 ° C. desirable. The defects due to silicic acid are approximately halved when the temperature of the treatment liquid is raised to 40 ° C., reduced to about 1/3 when raised to 60 ° C., and almost zero when raised to 75 ° C. On the other hand, when the temperature is raised above 80 ° C., a dehydration condensation reaction occurs and CARE processing is inhibited. In addition, bubbles are easily generated in the processing liquid, and processing non-uniformity is easily generated. Further, when the CARE processing is performed under a reduced pressure from the atmospheric pressure, the optimum temperature range is lowered as a whole, and when the CARE processing is performed under a high pressure, the optimum temperature range is raised as a whole. Considering simplification of the structure of the CARE processing and manufacturing apparatus and ease of maintenance, atmospheric pressure processing is desirable.

  It is preferable that the CARE processing liquid is continuously replaced with a cleaning liquid without interposing a substrate drying step. As a result, since the silicic acid such as orthosilicic acid dissolved in the processing liquid on the substrate surface is diluted and removed by the cleaning liquid continuously replaced, the orthosilicic acid dissolved in the processing liquid is removed. It is possible to more reliably remove silicic acid such as from the substrate surface, and to further reduce defects. Since the processing liquid is continuously replaced with the cleaning liquid, it is desirable that the processing liquid be the same substance as the cleaning liquid. From this point of view, it is preferable to use pure water as the treatment liquid.

  Next, a substrate manufacturing apparatus (substrate processing apparatus) for CARE processing will be described. 1 and 2 show an example of a substrate processing apparatus that performs processing by catalyst-based etching on the main surface of the substrate. FIG. 1 is a partial cross-sectional view of the substrate processing apparatus, and FIG. 2 is a plan view of the substrate processing apparatus. In the following, the case where the upper surface M1 used as the main surface of the substrate M is CARE processed using the substrate processing apparatus shown in FIGS. 1 and 2 will be described. However, when the lower surface M2 of the substrate M is also used 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 liquid is interposed between the processing reference surface 33 and the main surface, the cleaning liquid supply means 4 for supplying the processing liquid, the processing liquid supply means 9 for supplying the processing liquid 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 adjustment liquid, the cleaning liquid, and the processing liquid supplied from the processing liquid 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. 1, the state in which the substrate temperature adjusting liquid, the cleaning liquid, and the processing liquid 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 31 is attached to a catalyst surface plate mounting portion 72 of the relative motion means 7 described later. The catalyst surface plate 31 includes a surface plate body 32, a base material formed on the entire surface of the surface plate body so as to cover the surface plate body, and a processing reference surface 33 on which the catalyst is deposited. . Therefore, the catalyst material on the processing reference surface 33 faces the substrate M.

  The overall shape of the catalyst platen 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 is formed is not particularly limited. For example, a flat, hemispherical, or rounded shape can be used.

  The processing liquid supply means 9 includes a processing liquid supply hole formed in the center of the catalyst surface plate 31, a processing liquid supply nozzle 91 that is disposed in the catalyst surface plate mounting portion 72, and supplies the processing liquid to the processing liquid supply hole. And a pipe (not shown) for supplying the processing liquid to the processing liquid supply nozzle 91. The processing liquid is supplied to the processing liquid supply nozzle 91 in the catalyst surface plate mounting portion 72 through the piping in the arm portion 51, and the main surface of the substrate M from the processing liquid supply hole formed in the center of the catalyst surface plate 31. Supplied on M1. Here, the processing liquid 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 liquid temperature. It is desirable.

  The temperature adjusting liquid / cleaning liquid supply means 4 is provided at the tip 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 of the substrate M placed on the support portion 21. And a spray nozzle 42 that sprays the temperature adjusting liquid and the cleaning liquid toward the main surface of the substrate M placed on the support portion 21. The supply pipe 41 is connected to, for example, a processing liquid storage tank (not shown), a temperature regulator (not shown), and a pressure pump (not shown) provided outside the chamber 6. 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 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. In the case where the temperature of the main surface of the substrate M is adjusted using another means such as a heater or a lamp without using the liquid, the means 4, the supply pipe 41, and the spray nozzle 42 are dedicated means for supplying the 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 of the substrate M placed on the support portion 21. A shaft portion 52 extending in a direction perpendicular to the main surface of the substrate M placed on the support portion 21, and a lower end of the shaft portion 52. The base part 53 to support is provided, and the guide 54 which is arrange | positioned around the chamber 6 and defines the movement path | route of the base part 53 is provided. The arm portion 51 can move in the longitudinal direction (see a double arrow C in FIGS. 1 and 2). 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. 1). 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 of the substrate M placed on the support portion 21 (FIG. 1, FIG. 1). (See double arrow E in 2). 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. 2), and the guide 54 in the second direction. The arm portion 51 can be moved in the second direction by moving along (see the double arrow G in FIG. 2). By such movement of the arm portion 51, the catalyst surface plate 31 can be disposed at a predetermined position on the main surface of the substrate M placed on the support portion 21.

  The substrate processing apparatus 1 includes relative motion means 7 that relatively moves the processing reference surface 33 and the main surface. 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 of the substrate M placed on the support portion 21, and the main surface of the substrate M placed on the support portion 21 by rotation driving means (not shown). And an axis perpendicular to the axis of rotation (see arrow A in FIG. 1). 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. The relative motion means 7 includes a catalyst surface plate mounting portion 72 to which the catalyst surface plate 31 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 of the substrate M placed on the support portion 21 (FIG. 1, FIG. 1). (See arrow B in 2).

  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 for applying a load to the catalyst surface plate 31, and a load applied to the catalyst surface plate 31 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 31 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, rotation speed (catalyst platen, substrate), processing liquid of the substrate M prepared separately) 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.

When performing processing by catalyst-based etching using the substrate processing apparatus shown in FIGS. 1 and 2, 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 liquid is supplied onto the upper surface M1 from the processing liquid supply nozzle 91, and between the upper surface M1 and the processing reference surface 33. A processing solution is interposed between the two. Since the treatment liquid and the temperature adjustment 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 liquid, 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 liquid 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 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 higher than normal temperature, and then the temperature is changed to finally be normal temperature. This is because the substrate processing operation becomes easier when the temperature of the substrate M is finally set to room temperature. The temperature change may be changed stepwise or may be changed continuously. Further, at the beginning of cleaning, if the temperature of the cleaning liquid is set higher than the temperature of the processing liquid during CARE processing, the solubility of silicic acid such as orthosilicic acid in the cleaning liquid increases, which is effective in reducing defects.

  In this embodiment, the method of uniformly controlling the temperature of the upper surface M1 of the substrate M by the temperature adjustment liquid supplied from the injection nozzle 42 is shown, but the present invention is not limited to this, and a heater, a lamp, or the like may be used. That is, temperature adjustment may be performed by adjusting heat radiation, airflow, and environmental temperature. The method using the temperature adjusting liquid has a feature that the mechanism of the apparatus can be simplified because the temperature adjusting liquid also serves as a cleaning liquid. On the other hand, the method using heat radiation or airflow generally has a feature of having a high-speed temperature rising / falling characteristic.

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 against the main surface of the substrate M. However, the processing reference surface of the substrate surface creation means is used. Furthermore, the present invention can also be applied to a substrate processing apparatus that presses the main surface of the substrate.
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.
Further, in this embodiment, the present invention is applied to a substrate processing apparatus of a type in which a processing liquid supply means is provided in the substrate surface creation means and the processing liquid is supplied from the processing liquid supply means. The present invention can also be applied to the case where the processing liquid is supplied toward the main surface, or the case where the processing liquid supply means is provided in the substrate support means and the processing liquid is supplied from the substrate support means. Further, the present invention can also be applied to the case where the processing liquid is stored in the chamber and the processing based on the catalyst reference etching is performed in a state where the substrate surface creation means and the substrate support means are placed in the processing liquid.

In this embodiment, the present invention is applied to a substrate processing apparatus of a type that relatively moves the processing reference surface 33 and the main surface by rotating both the processing reference surface 33 and the main surface. The present invention can also be applied to a substrate processing apparatus of a type in which the processing reference surface 33 and the main surface are moved relative to each other by a method.
Further, in this embodiment, the present invention is applied to a substrate type processing apparatus that processes substrates one by one. However, the present invention is also applied to a batch type substrate processing apparatus that processes a plurality of substrates simultaneously. it can. Moreover, although the case where it processed over the main surface whole surface of a board | substrate was shown here, if necessary, only the local processing which processes only a predetermined local part may be performed, and these processing may be used together. 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, a multilayer reflective film in which high refractive index layers and low refractive index layers are alternately laminated on the main surface of the substrate M manufactured by the method described in the substrate manufacturing method of the first embodiment. Then, a substrate with a multilayer reflective film is produced, or a protective film is 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 multilayer film surface and high surface smoothness.

  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, even if the inspection is performed after the multilayer film is formed, it becomes a background noise at the time of phase defect inspection and the inspection sensitivity is lowered. According to the embodiment of the present invention, since sufficient surface smoothness can be obtained including the surface of the multilayer film in addition to the substrate surface, 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 this third embodiment, a binary mask blank is manufactured by forming a light shielding film as a transfer pattern thin film on the main surface of the substrate M manufactured by the method described in the substrate manufacturing method of the first embodiment. Alternatively, a half-tone phase shift mask blank is manufactured by forming a light semi-transmissive film as a transfer pattern thin film, or a half-tone phase shift mask by sequentially forming a light semi-transmissive film and a light-shielding film as a transfer pattern thin film. A 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 for 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 substrate M obtained by the substrate manufacturing method of the first embodiment or the substrate with the multilayer reflective film obtained by the method of manufacturing the substrate with the multilayer reflective film of the second embodiment is used. Since the mask blank is manufactured, it is possible to prevent deterioration of characteristics due to substrate factors, and it is possible to manufacture a mask blank having desired characteristics.

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 apparent from the material composition, the surface of the glass substrate is made of an oxide containing silicon. 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. 1 and 2, 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 main body 32 made of stainless steel (SUS), a fluorine rubber pad formed on the entire surface of the surface plate main body 32 so as to cover the surface plate main body 32, and a glass substrate are opposed to each other. A catalyst surface plate 31 having a processing reference surface 33 made of a platinum thin film formed by sputtering using a platinum (Pt) target in an argon (Ar) gas on the entire surface of the fluorine-based rubber pad on the side was used. Here, the diameter of the catalyst surface plate is 100 mm, and the film thickness of the Pt thin film formed on the fluorine rubber pad is 100 nm.
Processing and cleaning conditions are as follows.
Treatment liquid: Pure water Substrate temperature adjustment and cleaning liquid: Pure water Clean room room temperature: 23 ° C
Temperature of processing solution and substrate temperature adjusting solution: 40 ° 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 31): 10 rotations / minute Processing pressure: 100 hPa
Processing allowance: 10nm

First, the glass substrate was placed and fixed on the support portion 21 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 ( By the double arrow G), the catalyst surface plate 31 was disposed in a state where the processing reference surface 33 of the catalyst surface plate 31 was disposed to face the main surface of the glass substrate. The arrangement position of the catalyst surface plate 31 is a position where the processing reference surface 33 of the catalyst surface plate 31 can contact or approach the entire main surface of the glass substrate when the glass substrate and the catalyst surface plate 31 are rotated. It is.

  Thereafter, the glass substrate is rotated at a rotation speed of 10.3 rotations / minute and the catalyst surface plate 31 is rotated at a rotation speed of 10 rotations / minute. Here, the glass substrate and the catalyst platen 31 are rotated so that the rotation direction of the glass substrate and the rotation direction of the catalyst platen 31 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. Moreover, both rotation speeds are set to be slightly different. Thereby, the processing reference surface 33 of the catalyst surface plate 31 can be moved relative to the main surface 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 and the catalyst surface plate 31, a temperature adjusting liquid for adjusting the substrate temperature was sprayed from the spray nozzle 42 to the substrate, and the processing liquid was supplied from the processing liquid supply nozzle 91 to the substrate surface. Both the temperature adjusting solution and the treatment solution are 40 ° C. pure water. The room temperature of the clean room, which is the ambient temperature at this time, is 23 ° C., and the temperature adjustment liquid and the treatment liquid are set to a temperature higher than the normal temperature. In this way, 40 ° 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 40 ° C. pure water is interposed between the processing reference surface 33. I let you. In that state, the processing reference surface 33 of the catalyst surface plate 31 was brought into contact with or brought close to the surface of the glass substrate by the vertical movement of the arm portion 51 (double arrow D). At that time, the load (processing pressure) applied to the glass substrate was controlled to 100 hPa.
Thereafter, when the machining allowance reaches 10 nm, the supply of the treatment liquid at 40 ° C. is stopped, and the catalyst surface plate 31 is moved from the main surface of the glass substrate to a predetermined level by moving the arm portion 51 up and down (double arrow D). Just a distance away. 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 and the catalyst surface plate 31 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 before and after processing by 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 0.049 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 Teron 610 manufactured by KLA-Tencor) is used for a defect inspection of the main surface of the glass substrate after processing by catalyst-based etching, for a 132 mm × 132 mm area excluding the peripheral area of the substrate. It was performed using. 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 convex defects detected on the main surface after processing (including fatal defects and pseudo defects) was 72. When the detected convex defects were examined by energy dispersive X-ray spectroscopy (EDX), there were 13 defects due to silicic acid (including fatal defects and pseudo defects). Incidentally, as described in the comparative example described later, in the conventional method in which the temperature of the processing liquid is set to room temperature (23 ° C.) and the temperature adjusting liquid for heating the substrate is not used, the number of detected convex defects on the main surface after processing. The number of defects (including fatal defects and pseudo defects) was 80, and the number of defects caused by silicic acid (including fatal defects and pseudo defects) was 24. According to this example in which CARE processing was performed at 40 ° C., the number of defects (including fatal defects and pseudo defects) caused by silicic acid could be almost halved.
Further, when 20 glass substrates were produced by the method of Example 1, the total number and the surface roughness were good, with a root mean square roughness (Rms) of 0.051 nm or less, and defects caused by silicic acid (fatal) The number of defects (including defects and pseudo defects) was as small as 15 or less.
By the method of Example 1, a glass substrate having a low-defect and high smooth main surface was stably obtained.

B. Next, a high refractive index layer (film thickness: 4.2 nm) made of a silicon film (Si) is formed on the main surface of the glass substrate thus produced by ion beam sputtering. A multilayer reflective film (thickness: 280 nm) is formed by alternately stacking 40 pairs of low refractive index layers (2.8 nm) made of a molybdenum film (Mo) alternately with one pair of high refractive index layer and low refractive index layer. Formed.
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 (Rms 0.17 nm), 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 defects detected on the surface of the protective film was 17,504 (including fatal defects and pseudo defects) with a sensitivity capable of detecting 21.5 nm size defects (convex defects) in terms of SEVD. In defect inspection, pseudo defects dominate. When the defect inspection was performed with a sensitivity capable of detecting a 25 nm size defect (convex defect) in terms of SEVD, the number was as small as 50 (not including pseudo defects). 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
In this embodiment, in the CARE processing in the first embodiment, only the temperature of the treatment liquid made of pure water and the temperature of the substrate temperature adjustment liquid are changed from 40 ° C. to 60 ° C., and the rest is changed from the substrate material and the pretreatment to 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 until production of the above. Therefore, the processing and cleaning conditions are as follows.
Treatment liquid: Pure water Substrate temperature adjustment and cleaning liquid: Pure water Clean room room temperature: 23 ° C
Temperature of processing solution and substrate temperature adjusting solution: 60 ° 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 31): 10 rotations / minute Processing pressure: 100 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 0.053 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 0.053 nm in terms of root mean square roughness (Rms) by CARE processing in which the temperature of pure water as the treatment liquid was 60 ° C.
Moreover, the defect inspection of the upper surface of the glass substrate after processing by CARE processing was performed similarly to Example 1.
The number of detected convex defects (including fatal defects and pseudo defects) on the main surface after processing was 55, and of these, 8 defects (including fatal defects and pseudo defects) were caused by silicic acid. As described in the comparative example described later, in the conventional method in which the temperature of the processing liquid is set to room temperature (23 ° C.) and the temperature adjusting liquid for heating the substrate is not used, the number of detected convex defects on the main surface after processing (fatal) There were 80 defects (including defects and pseudo defects), and 24 defects (including fatal defects and pseudo defects) due to silicic acid. According to this example in which CARE processing was performed at 60 ° C., the number of defects caused by silicic acid could be reduced to 1/3.
Further, when 20 glass substrates were produced by the method of Example 2, the total number and the surface roughness were good, with a root mean square roughness (Rms) of 0.056 nm or less, and defects caused by silicic acid (fatal) The number of defects (including defects and pseudo defects) was as small as 10 or less.
By the method of Example 2, a glass substrate having a main surface made of silicon oxide having high smoothness and low defects was stably obtained.

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 (Rms was 0.17 nm), 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 defects detected on the surface of the protective film was 16,211 (including individual fatal defects and pseudo defects) with a sensitivity capable of detecting defects (convex defects) of 21.5 mn size in terms of SEVD. In defect inspection, pseudo defects dominate. When a sensitivity defect inspection capable of detecting a 25 nm size defect (convex defect) in terms of SEVD was performed, the number was 47 (not including pseudo defects), and the number was small.
By the method of Example 2, a substrate with a multilayer reflection film having high smoothness and low defects was obtained.
Moreover, the reflective mask blank and reflective mask for EUV exposure which maintained the surface state of the low defect and high smoothness by the method of Example 2 were obtained.

Example 3
In this embodiment, in the CARE processing in the first embodiment, only the temperature of the treatment liquid made of pure water and the temperature of the substrate temperature adjustment liquid are changed from 40 ° C. to 75 ° C., and the rest is changed from the substrate material and the pretreatment to 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 until production of the above. Therefore, the processing and cleaning conditions are as follows.
Treatment liquid: Pure water Substrate temperature adjustment and cleaning liquid: Pure water Clean room room temperature: 23 ° C
Temperature of processing solution and substrate temperature adjusting solution: 75 ° 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 31): 10 rotations / minute Processing pressure: 100 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 0.059 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 0.059 nm in terms of root mean square roughness (Rms) by CARE processing in which the temperature of pure water as the treatment liquid was 75 ° C.
Moreover, the defect inspection of the upper surface of the glass substrate after processing by CARE processing was performed similarly to Example 1.
The number of detected convex defects (including fatal defects and pseudo defects) on the main surface after processing was 47, and of these, the number of defects caused by silicic acid (including fatal defects and pseudo defects) was zero. As described in the comparative example described later, in the conventional method in which the temperature of the processing liquid is set to room temperature (23 ° C.) and the temperature adjusting liquid for heating the substrate is not used, the number of detected convex defects on the main surface after processing (fatal) There were 80 defects (including defects and pseudo defects), and 24 defects (including fatal defects and pseudo defects) due to silicic acid. In this example in which CARE processing was performed at 75 ° C., the number of defects (including fatal defects and pseudo defects) caused by silicic acid could be reduced to zero.
Further, when 20 glass substrates were produced by the method of Example 3, the total number and the surface roughness were as good as 0.061 nm or less in root mean square roughness (Rms), and defects caused by silicic acid (fatal) The number of defects (including defects and pseudo defects) was as small as 1 or less.
By the method of Example 3, a glass substrate having a main surface made of silicon oxide having high smoothness and low defects was stably obtained.

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 (Rms was 0.17 nm), 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 defects detected on the surface of the protective film was 16,549 (including fatal defects and pseudo defects) with a sensitivity capable of detecting 21.5 nm size defects (convex defects) in terms of SEVD. In defect inspection, pseudo defects dominate. When the defect inspection was performed with a sensitivity capable of detecting a 25 nm size defect (convex defect) in terms of SEVD, the number was as small as 39 (not including pseudo defects).
By the method of Example 3, a substrate with a multilayer reflection film having high smoothness and low defects was obtained.
Moreover, the reflective mask blank and reflective mask for EUV exposure which maintained the surface state of the low defect and high smoothness by the method of Example 3 were obtained.

Example 4
In this embodiment, in the CARE processing in the first embodiment, only the temperature of the treatment liquid made of pure water and the temperature of the substrate temperature adjustment liquid are changed from 40 ° C. to 80 ° C., and the rest is changed from the substrate material and the pre-treatment to 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 until production of the above. Therefore, the processing and cleaning conditions are as follows.
Treatment liquid: Pure water Substrate temperature adjustment and cleaning liquid: Pure water Clean room room temperature: 23 ° C
Temperature of processing solution and substrate temperature adjusting solution: 80 ° 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 31): 10 rotations / minute Processing pressure: 100 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 the processing was 0.06 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 0.06 nm in terms of root mean square roughness (Rms) by CARE processing in which the temperature of pure water as the treatment liquid was 80 ° C.
Moreover, the defect inspection of the upper surface of the glass substrate after processing by CARE processing was performed similarly to Example 1.
The number of detected convex defects (including fatal defects and pseudo defects) on the main surface after processing was 46, of which 0 defects (including fatal defects and pseudo defects) were caused by silicic acid. As described in the comparative example described later, in the conventional method in which the temperature of the processing liquid is set to room temperature (23 ° C.) and the temperature adjusting liquid for heating the substrate is not used, the number of detected convex defects on the main surface after processing (fatal) There were 80 defects (including defects and pseudo defects), and the number of defects caused by silicic acid (including fatal defects and pseudo defects) was 24. In this example in which CARE processing was performed at 80 ° C., the number of defects (including fatal defects and pseudo defects) caused by silicic acid could be reduced to zero.
Further, when 20 glass substrates were produced by the method of Example 4, the total number and the surface roughness were as good as 0.063 nm or less in root mean square roughness (Rms), and defects due to silicic acid (fatal) The number of defects (including defects and pseudo defects) was as small as 1 or less.
By the method of Example 4, a glass substrate having a main surface made of silicon oxide having high smoothness and low defects was stably obtained.

  FIG. 3 shows the temperature dependency of the number of defects on the surface of the glass substrate and the surface roughness in the CARE processing of the processing liquid and the substrate temperature adjusting liquid. Here, the treatment liquid and the substrate temperature adjustment liquid are pure water at the same temperature. In the figure, A represents the number of convex defects (including fatal defects and pseudo defects), B represents the number of defects caused by silicic acid (including fatal defects and pseudo defects), and C represents the surface roughness (Rms). The number of convex defects (including fatal defects and pseudo defects) decreases when the temperature of the processing solution and the substrate temperature adjusting solution is raised compared to the normal temperature of 23 ° C. ). The number of defects due to silicic acid (including fatal defects and pseudo-defects) is almost halved at 60 ° C when the temperature of the processing solution and the substrate temperature adjusting solution is 40 ° C compared to the conventional method of room temperature processing (23 ° C). Then, it becomes 1/3 and becomes zero at 75 ° C. or higher. On the other hand, the surface roughness monotonously increases as the temperature rises, but it is 0.06 nm even at 80 ° C., which is well below the required value of 0.08 nm. When a smaller surface roughness is required, it can be improved by optimizing the catalyst material, pad hardness, processing pressure, etc. of the catalyst surface plate to be used.

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 (Rms was 0.17 nm), 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 defects detected on the surface of the protective film was 20,310 (including fatal defects and pseudo defects) with a sensitivity capable of detecting 21.5 nm size defects (convex defects) in terms of SEVD. In defect inspection, pseudo defects dominate. When the defect inspection was performed with a sensitivity capable of detecting a 25 nm size defect (convex defect) in terms of SEVD, there were as few as 32 (not including pseudo defects).
By the method of Example 4, a substrate with a multilayer reflection film having high smoothness and low defects was obtained.
Moreover, the reflective mask blank and reflective mask for EUV exposure which maintained the surface state of the low defect and high smoothness by the method of Example 4 were obtained.

Example 5 FIG.
In this example, in the CARE processing in Example 2, only the temperature of the cleaning water composed of pure water was changed from 23 ° C. fixing to 80 ° C. through 40 ° C. to 23 ° C. in three stages, otherwise 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 2 from the substrate material and its pretreatment to the production of the reflective mask. Therefore, the processing and cleaning conditions are as follows.
Treatment liquid: Pure water Substrate temperature adjustment and cleaning liquid: Pure water Clean room room temperature: 23 ° C
Temperature of processing solution and substrate temperature adjusting solution: 60 ° C
Cleaning liquid temperature: first stage 80 ° C., second stage 40 ° C., third stage 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 31): 10 rotations / minute
Processing allowance: 10nm

In the same manner as in Example 2, 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 is 0.052 nm in terms of root mean square roughness (Rms), which is almost the same as 0.053 nm in Example 2 and is well below the required value of 0.08 nm. It was a thing. The surface roughness of the upper surface was improved from 0.157 nm to 0.052 nm in terms of root mean square roughness (Rms) by this CARE processing.
Moreover, the defect inspection of the upper surface of the glass substrate after processing by CARE processing was performed similarly to Example 2.
The number of detected convex defects (including fatal defects and pseudo defects) on the main surface after processing was 48, and among these, the number of defects caused by silicic acid (including fatal defects and pseudo defects) was three. As described in the comparative example described later, in the conventional method in which the temperature of the processing liquid is set to room temperature (23 ° C.) and the temperature adjusting liquid for heating the substrate is not used, the number of detected convex defects on the main surface after processing (fatal) There were 80 defects (including defects and pseudo defects), and 24 defects (including fatal defects and pseudo defects) due to silicic acid. By this example, the number of defects (including fatal defects and pseudo defects) caused by silicic acid could be reduced to 1/8 compared with the conventional method. Further, in the case of Example 2 in which the temperature of the cleaning liquid is kept constant at 23 ° C., the number of defects due to silicic acid (including fatal defects and pseudo defects) is eight. The temperature of the cleaning solution is initially set to 80 ° C., and is gradually reduced to 23 ° C., so that the number of defects caused by silicic acid (including fatal defects and pseudo defects) is almost 1/3 compared to the case where the temperature is fixed at 23 ° C. We were able to reduce it. The high temperature cleaning liquid increases the solubility of orthosilicic acid in the cleaning liquid, and when the silicic acid such as orthosilicic acid eluted in the cleaning liquid is sufficiently diluted and removed, the above effect is obtained. Conceivable.
Further, when 20 glass substrates were produced by the method of Example 5, the total number and the surface roughness were good, with a root mean square roughness (Rms) of 0.053 nm or less, and defects caused by silicic acid (fatal) The number of defects (including defects and pseudo defects) was as small as 13 or less.
By the method of Example 5, a glass substrate having a main surface composed of silicon oxide having high smoothness and low defects was stably obtained.

In the same manner as in Example 2, 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 (Rms was 0.17 nm), 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 2. FIG.
The number of defects detected on the surface of the protective film was 18,436 (including fatal defects and pseudo defects) with a sensitivity capable of detecting 21.5 nm size defects (convex defects) in terms of SEVD, but the 21.5 nm size defect was detected. In defect inspection, pseudo defects dominate. When the defect inspection was performed with a sensitivity capable of detecting a 25 nm size defect (convex defect) in terms of SEVD, the number was as small as 42 (not including pseudo defects).
By the method of Example 5, a substrate with a multilayer reflection film having high smoothness and low defects was obtained.
Moreover, the reflective mask blank and reflective mask for EUV exposure which maintained the surface state of the low defect and high smoothness by the method of Example 5 were obtained.

Example 6
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 silicon oxide. The synthetic quartz glass substrate is obtained through the above-described rough polishing process, precision polishing process, and ultraprecision polishing process.
Otherwise, a glass substrate was produced in the same manner as in Example 2. That is, a glass substrate having a surface made of silicon oxide was manufactured by CARE processing in which the temperature of pure water as the treatment liquid and the substrate temperature adjusting liquid was 60 ° C. Therefore, the processing and cleaning conditions are as follows.
Treatment liquid: Pure water Substrate temperature adjustment and cleaning liquid: Pure water Clean room room temperature: 23 ° C
Temperature of processing solution and substrate temperature adjusting solution: 60 ° 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 31): 10 rotations / minute Processing pressure: 100 hPa
Processing allowance: 10nm

In the same manner as in Example 2, 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 0.052 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 0.052 nm in terms of root mean square roughness (Rms) by catalyst-based etching with the temperature of pure water as the treatment liquid being 60 ° C.
Moreover, the defect inspection of the upper surface of the glass substrate after processing by CARE processing was performed similarly to Example 2.
The number of detected convex defects (including fatal defects and pseudo defects) on the main surface after processing was 42, and among these, the number of defects due to silicic acid (including fatal defects and pseudo defects) was 7.
Further, when 20 glass substrates were produced by the method of Example 6, the total number and the surface roughness were good, the root mean square roughness (Rms) being 0.054 nm or less, and the number of defects due to silicic acid was also Less than 11 pieces.
By the method of Example 6, a glass substrate having a main surface made of silicon oxide having high smoothness and low defects 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 half-tone phase shift mask blank for ArF excimer laser exposure that maintains a surface state with low defects and high smoothness was produced.

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 treatment liquid made of pure water was changed from 40 ° C. to 23 ° C. of room temperature, and other than that, the substrate material and its pre-treatment were used to manufacture a 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.
Treatment liquid: Pure water Cleaning liquid: Pure water Clean room room temperature: 23 ° C
Treatment liquid 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 31): 10 rotations / minute Processing pressure: 100 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 0.04 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 0.04 nm in root mean square roughness (Rms) by CARE processing in which the temperature of pure water as the treatment liquid was 23 ° C.
Moreover, the defect inspection of the upper surface of the glass substrate after processing by CARE processing was performed similarly to Example 1.
The number of detected convex defects (including fatal defects and pseudo defects) on the main surface after processing was 80, and among these, the number of defects due to silicic acid (including fatal defects and pseudo defects) was 24.
Moreover, when 20 glass substrates were produced by this method, the total number and the surface roughness were as good as 0.046 nm or less in root mean square roughness (Rms), but the number of defects due to silicic acid was 24. There were as many as ~ 45.
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.

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 (Rms 0.17 nm), 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 defects detected on the surface of the protective film was 17,872 (including fatal defects and pseudo defects) with a sensitivity capable of detecting 21.5 nm size defects (convex defects) in terms of SEVD. In defect inspection, pseudo defects dominate. When defect inspection was performed with a sensitivity capable of detecting a 25 nm size defect (convex defect) in terms of SEVD, there were as many as 103 (not including pseudo defects).
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.
Moreover, in the method of the comparative example, although high smoothness was obtained, the reflective mask blank and reflective mask for EUV exposure of the surface state with many defects were manufactured.

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.
In the above-described embodiment, the present invention is applied to the case where the main surface of the mask blank substrate is processed by the catalyst reference etching. However, the catalyst reference etching is performed on the main surface of the magnetic recording medium substrate. The present invention can also be applied when processing according to the above.

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 ... Process liquid supply means, 21 ... Support part, 22 ... Plane part, 22a ... Accommodating part, 31 ... Catalyst surface plate, 32 ... Surface plate body, 33 ... Processing reference plane, 41 ... Supply pipe, 42 ... Injection nozzle, DESCRIPTION OF SYMBOLS 51 ... Arm part, 52 ... Shaft part, 53 ... Base part, 54 ... Guide, 61 ... Opening part, 62 ... Discharge port, 63 ... Bottom part, 71 ... Shaft part 71, 72 ... Catalyst surface plate attaching part, 81 ... Air Cylinder, 82 ... load cell, 91 ... treatment liquid supply nozzle, M ... substrate, M1 ... upper surface, M2 ... lower surface.

Claims (13)

A method for manufacturing a mask blank substrate,
A substrate preparation step of preparing a mask blank substrate made of a material containing at least a main surface of silicon oxide;
The processing reference surface of the catalytic material is brought into contact with or close to the main surface of the substrate, and either one or both of the processing reference surface and the substrate are rotated about an axis perpendicular to the main surface of the substrate. While the processing liquid is supplied toward the main surface, the main surface and the processing reference surface are moved relative to each other in a state where the processing liquid is interposed between the processing reference surface and the main surface. And a step of performing catalyst-based etching on the main surface,
The catalyst-based etching step is performed in a clean room or a clean booth,
The treatment liquid is a liquid selected from pure water, ozone water, carbonated water, hydrogen water, alkaline aqueous solution, and acidic aqueous solution, and the temperature of the treatment liquid during the catalyst-based etching is the clean room or clean booth. temperature der above room temperature of the inner is,
The working reference plane is a manufacturing method of a substrate for a mask blank, it characterized that you have positioned above the substrate.   2. The method for manufacturing a mask blank substrate according to claim 1, wherein at least a main surface of the substrate is heated to a temperature exceeding the room temperature during the catalyst-based etching step.   3. The method according to claim 1, further comprising a cleaning step of cleaning the main surface of the substrate with the cleaning liquid after the treatment liquid is continuously replaced with a cleaning liquid after the catalyst reference etching process is completed. A method for manufacturing a mask blank substrate.   4. The mask according to claim 3, wherein, in the cleaning step, the temperature of the cleaning liquid is adjusted according to an elapsed time so that the temperature of the cleaning liquid is higher than the room temperature at the start time and at least at the end time. A method for manufacturing a blank substrate.   5. The method for manufacturing a mask blank substrate according to claim 3, wherein the treatment liquid and the cleaning liquid are the same substance.   The method for manufacturing a mask blank substrate according to any one of claims 1 to 5, wherein the temperature of the treatment liquid is in the range of 40 ° C to 80 ° C.   The method for manufacturing a mask blank substrate according to claim 1, wherein the processing reference surface has a size smaller than that of the substrate. A multilayer reflective film is formed on a main surface of a mask blank substrate manufactured by the method for manufacturing a mask blank substrate according to any one of claims 1 to 7 . Production method. It is obtained by the manufacturing method of the board | substrate with a multilayer reflective film of Claim 8 on the main surface of the mask blank board | substrate obtained by the manufacturing method of the mask blank board | substrate as described in any one of Claims 1 thru | or 7. A method for producing a mask blank, comprising: forming a transfer pattern thin film on a multilayer reflective film of the substrate with the multilayer reflective film. 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 claim 9 to form a transfer pattern. A mask blank substrate manufacturing apparatus for manufacturing a mask blank substrate by processing the main surface of a mask blank substrate by catalyst-based etching,
Substrate support means for supporting the substrate;
A substrate surface creation means having a processing reference surface of a catalytic substance disposed opposite to the main surface of the substrate supported by the substrate support means;
In a state where the processing reference surface and the main surface are in contact with or close to each other, either the processing reference surface or the substrate or both are rotated around an axis in a direction perpendicular to the main surface of the substrate. Relative motion means for relative motion,
A processing liquid supply means for interposing a processing liquid between the processing reference surface and the main surface by supplying a processing liquid toward the main surface;
A temperature adjusting means for making the temperature of the treatment liquid higher than room temperature in a clean room or a clean booth where the catalyst-based etching is performed,
Said processing liquid is pure water, ozone water, carbonated water, hydrogen water, Ri liquid der selected from among the alkaline aqueous solution and an acidic aqueous solution,
The working reference plane, the substrate manufacturing apparatus for a mask blank, characterized that you have positioned above the substrate. Means for supplying a cleaning liquid, a substrate manufacturing apparatus for a mask blank according to claim 1 1, characterized in that it comprises a temperature adjusting means for adjusting the temperature from the temperature of the treatment liquid to the room temperature of the cleaning solution.   13. The mask blank substrate manufacturing apparatus according to claim 11, wherein the processing reference surface has a size smaller than that of the substrate.

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