WO2011001522A1

WO2011001522A1 - Mask blank storing case, mask blank storing method and mask blank storing body

Info

Publication number: WO2011001522A1
Application number: PCT/JP2009/062047
Authority: WO
Inventors: 康弘水越; 修花岡
Original assignee: Hoya株式会社
Priority date: 2009-07-01
Filing date: 2009-07-01
Publication date: 2011-01-06

Abstract

Provided is a mask blank storing case which can firmly fix a mask blank in the case with uniform fixing load, and furthermore, has improved airtightness of the case. The mask blank storing case is provided with a case main body (5) which has an opened upper section, and a cover body (6) which covers the case main body (5), and the mask blank storing case stores the mask blank inside. The cover body (5) and the case main body (6) are fixed such that fixing load is uniformly applied on the entire circumference of a joint section, by having a fixing frame (10), which surrounds the joint section on the entire circumference when the case main body (5) is covered with the cover body (6), and the fixing member composed of a fixing piece (11) engage with each other.

Description

Mask blank storage case, mask blank storage method, and mask blank storage body

The present invention relates to a storage case for storing a mask blank used for manufacturing a photomask or the like used for manufacturing an electronic device, and a storage method thereof.

Recent electronic devices, particularly semiconductor elements, color filters for liquid crystal monitors, TFT elements, and the like, are required to be further miniaturized with the rapid development of IT technology. One of the technologies that support such a fine processing technology is a lithography technology using a photomask called a transfer mask. In this lithography technique, a fine pattern is formed on a silicon wafer by exposing an electromagnetic wave of an exposure light source to a silicon wafer with a resist film through a transfer mask. This transfer mask is usually manufactured by forming a pattern serving as an original plate using a lithography technique on a mask blank in which a light-shielding film is formed on a light-transmitting substrate. By the way, if there is a foreign substance such as a particle on the surface of the mask blank, it will cause a defect in the pattern to be formed. Therefore, it is necessary to store it cleanly so that the foreign substance or the like does not adhere to the surface of the mask blank.

As a case for storing, storing and transporting such a mask blank, a mask transport case as disclosed in, for example, Patent Document 1 below is known. That is, a conventional case for storing and storing a mask blank is a case in which several to several dozen mask blanks are held side by side in an inner case called a carrier, and the inner case holding the mask blank is placed in an outer box (case body ) And a cover on the outer box to accommodate the mask blank.

7 to 9 show a storage case having the same structure as that disclosed in Patent Document 1, FIG. 7 is a perspective view showing a cover of the storage case, and FIG. 8 stores the mask blank in the middle case. FIG. 9 is a perspective view showing a case main body (outer case) of the storage case.
This storage case has a structure in which the mask blank 1 is stored in an intermediate case 2, the intermediate case 2 is stored in a case main body 3, and the lid 4 is covered on the opening side of the case main body 3.

The middle case 2 is formed by forming a plurality of

grooves

21 and 22 from the opening side (upper side) to the bottom side (lower side) at a predetermined interval on one inner surface facing each other. Opening windows 23 and 24 and an opening 27 are provided on the bottom of the bottom surface side of the 21 and 22 and the bottom of the middle case, respectively, and a substrate support 26 is formed on the bottom of the middle case. The lower end surface of the blank 1 is supported (FIG. 8). Then,

concave surface portions

28 and 29 for housing and fixing the middle case 2 in the case body 3 are respectively formed on the other opposite outer surfaces of the middle case from the bottom surface side to the middle of the opening portion side. When several mask blanks 1 are inserted along the pair of

grooves

21 and 22 of the middle case 2, these mask blanks stand in parallel with each other at a predetermined interval.

The case body 3 is formed with projecting

portions

31 and 32 adapted to abut against the

concave surface portions

28 and 29 of the above-described middle case 2 on inner surfaces facing each other, and the bottom portions of the projecting

portions

31 and 32 are formed on the case body. The three bottom surfaces are also joined (FIG. 9). In addition, convex

portions

33 and 34 are formed on the opening side of one opposing outer surface. The outer peripheral surface 36 following the position slightly below the opening edge 35 of the case body 3 and the convex surfaces of the

convex portions

33 and 34 are formed on substantially the same plane.
The lid 4 is recessed in

engagement pieces

41 and 42 extending from the center of one opposing lower edge 47 (the edge on the opening side to be inserted into the case body and facing upward in FIG. 7). 43 and 44 are formed. Thereby, when the cover 4 is put on the case main body 3, the

concave portions

43 and 44 are respectively fitted to the

convex portions

33 and 34 of the case main body 3, whereby the cover 4 and the case main body 3 are fixed. It has a structure. Further, stoppers 45 and 46 which are in contact with the upper end surface 25 on the opening side of the middle case 2 and support and fix the middle case 2 in the vertical direction are formed on one inner surface so as to face each other.

Japanese Patent Publication No. 1-39653

As electronic devices have been improved in performance in recent years, patterns formed on transfer masks are required to be further miniaturized. In order to form such fine patterns, the cleanness of the mask blank is not extremely high. And is becoming unacceptable. Therefore, it is necessary to maintain the cleanliness as high as possible, particularly during storage of the mask blank, by suppressing as much as possible foreign matter from adhering to the mask blank.

As described above, the storage case of the conventional structure has a hook structure in which the

concave portions

43 and 44 of the lid 4 are fitted with the

convex portions

33 and 34 of the case main body 3 when the lid 4 is put on the case main body 3, respectively. The lid 4 and the case body 3 are fixed, and two of the four sides of the storage case are fixed. However, since the lid 4 and the case body 3 are made of a plastic material such as polypropylene and polyethylene and have some flexibility, the fixed load escapes at places other than the fixed portion by the hook structure. Such a problem arises.

(1) The fixed load on the mask blank at a location away from the fixed location (2 locations) due to the hook structure is weakened. For example, the mask blank in the storage case and the plastic parts supporting it by vibration during transportation Particles are generated due to rubbing and adhere to the mask blank, resulting in a foreign matter defect.

(2) For example, a chemically amplified resist that is advantageous for forming a miniaturized pattern with a semiconductor design rule D-RAM half pitch of 32 nm or less is susceptible to chemical component contamination due to its reaction mechanism. In other words, it has a property that its performance deteriorates when exposed to a slight acid or alkali atmosphere. For this reason, in the case of a mask blank with a chemically amplified resist film, it is not necessary to simply remove foreign substances such as particles, and it is necessary to store in a particularly clean atmosphere in order to eliminate the influence of chemical component contamination. The airtightness of the case is very important in that it prevents the entry of unstable outside air. However, in the conventional storage case, the airtightness is insufficient. Therefore, it is possible to increase the airtightness of the case by interposing a packing (elastic body) at the joint between the opening edge of the case body and the lower edge of the cover body when the case body is covered with a lid. However, the fixing load between the lid body and the case main body is weak at a location away from the fixing location by the hook structure, and the airtightness by the packing tends to be insufficient.

In the conventional storage case, for example, the joint between the lid and the case body is temporarily sealed with an adhesive tape. However, in the case of a commonly used adhesive tape, it has some air permeability. For example, even if the mask blank is stored and packed in a case in a clean atmosphere such as a clean room, depending on the subsequent storage atmosphere, the outside air may enter over time, and the storage case may contain some components contained in the outside air. May be contaminated. Furthermore, even if plastics that do not easily release any chemical components are used as the material of the storage case, the chemical components used in the base material and adhesive of the adhesive tape enter the case over time and become contaminated. There is a case. In particular, in the case of a mask blank on which the above-described chemically amplified resist film is formed, contamination due to contamination such as chemical components becomes a fatal defect. Thus, in the method of sealing the joint portion of the case with the adhesive tape, it is difficult to avoid contamination due to the entry of outside air, contamination due to the chemical components of the adhesive tape, and the like.

Accordingly, the present invention provides a mask blank storage case and storage method that solves the above-mentioned conventional problems, can firmly fix the mask blank in the case with a uniform fixing load, and improves the airtightness of the case. This is the first purpose. A second object of the present invention is to provide a storage case and a storage method suitable for a mask blank formed with a chemically amplified resist film that needs to be stored in a particularly clean atmosphere.

As a result of intensive studies to solve the above problems, the present inventor has found that the fixing member is engaged with the storage case so that the fixing load is applied substantially uniformly over the entire circumference of the joint portion between the case main body and the lid. It has been found that the mask blank in the case can be fixed with a uniform fixed load and the airtightness of the case can be improved by fixing the case body to the case body, and the present invention has been completed. It is.

That is, the present invention has the following configuration.
(Configuration 1) A mask blank storage case that includes a case main body that is open at the top and a lid that covers the case main body, and stores the mask blank therein, and a fixing member that engages with the storage case. The lid body and the case so that a fixed load is applied uniformly or substantially uniformly over the entire circumference of the joint portion between the opening edge portion of the case body and the lower edge portion of the lid body when the case body is covered with the lid body. Mask blank storage case characterized by fixing the case body.
According to the mask blank storage case of Configuration 1, the joint between the opening edge of the case body and the lower edge of the cover body when the case body is covered with the cover body by the fixing member engaged with the storage case In order to fix the lid and the case main body so that a fixed load is applied uniformly or almost uniformly over the entire circumference of the mask, the mask blank stored in the case can be fixed firmly with a uniform fixed load, for example, transportation, conveyance It is also possible to suppress the generation of particles due to rubbing between the mask blank in the storage case and the plastic parts that support the mask blank, and to prevent the particles from adhering to the mask blank. In addition, since it can be fixed so that a fixed load is applied uniformly or almost uniformly over the entire circumference of the joint between the lid and the case main body, the airtightness of the case can be improved, and unstable outside air can be prevented from entering. Can do.

(Configuration 2) The lid is formed by engaging a fixing member that surrounds the entire periphery of the joint portion between the opening edge of the case body and the lower edge of the lid when the case body is covered with the lid. The mask blank storage case according to Configuration 1, wherein a body and the case main body are fixed.
As one aspect of fixing the lid body and the case main body by the fixing member so that a fixed load is uniformly applied over the entire circumference of the joint portion, the case main body is covered with the lid body as in Configuration 2. It is to engage the fixing member that surrounds the entire circumference of the joint portion between the opening edge of the case body and the lower edge of the lid.

(Structure 3) The mask according to Structure 1, wherein the cover body and the case body are fixed by covering the case body with a fixing member on four sides of the storage case when the cover body is covered. Blank storage case.
As another aspect of fixing the lid body and the case main body by the fixing member so that a fixed load is uniformly applied over the entire circumference of the joint portion, as in Configuration 3, the case main body is covered with the lid body. The fixing member is put on the four sides of the storage case.

(Structure 4) The mask blank storage case according to structure 3, wherein the fixing member is covered at a plurality of locations per side of the storage case.
As described in Configuration 4, in Configuration 3 described above, the fixing member is covered over a plurality of locations per side of the storage case, so that a fixed load is uniformly applied over the entire circumference of the joint between the lid of the storage case and the case body. It can be easily fixed.

(Configuration 5) An elastic body is provided around at least one of the opening edge of the case body or the lower edge of the lid body, and the opening edge and lid of the case body when the case body is covered with the lid body The mask blank storage case according to any one of configurations 1 to 4, wherein the elastic body is interposed at a joint portion with a lower edge portion of the body.
As in Configuration 5, when the lid and the case main body are fixed by the fixing member, the lid is pressed by the fixing member, and the elastic body interposed in the joint portion with the case main body is crushed so that the inside of the case is sealed. be able to. In the storage case of the present invention, since it can be fixed so that a fixed load is applied uniformly or substantially uniformly over the entire circumference of the joint between the lid and the case body, the case can be further improved in airtightness using an elastic body. it can. In addition, the mask blank stored in the case can be securely fixed even during transportation and transportation, and particle generation can be suppressed.

(Structure 6) A mask blank storage method comprising storing a mask blank having a resist film in the mask blank storage case according to any one of structures 1 to 5.
By storing a mask blank having a resist film in the mask blank storage case according to any one of the structures 1 to 5, the mask blank can be fixed firmly with a uniform fixed load, for example, by vibration during transportation and transportation. Generation of particles in the storage case can be suppressed, and particle adhesion to the mask blank can be prevented. Moreover, it can fix so that fixed load may be applied uniformly or substantially uniformly over the perimeter of the junction part of a cover body and a case main body, and since airtightness of a case is high, the approach of unstable external air can be suppressed.

(Structure 7) The mask blank storing method according to Structure 6, wherein the resist is a chemically amplified resist.
According to the mask blank storing method of the present invention, the mask blank stored in the case is securely fixed even during transportation and transportation, and the case is highly airtight, so that the entry of unstable outside air can be suppressed. It is suitable for storing a mask blank formed with a chemically amplified resist film that needs to be stored in a particularly clean atmosphere in order to eliminate not only foreign matters such as particles but also contamination of chemical components.

(Configuration 8) A mask blank storage body in which a mask blank is stored by the storage method according to

Configuration

6 or 7.
According to the mask blank storage body of Configuration 8, since the mask blank is firmly fixed with a uniform fixed load, for example, generation of particles in the storage case is suppressed by vibration during transportation and transportation, and Particle adhesion can be prevented. Moreover, since the case is highly airtight, it is possible to suppress the entry of unstable outside air.

According to the present invention, in a mask blank storage case comprising a case body having an open top and a cover body that covers the case body, the lid body and the case body are fixed by a fixing member that engages with the storage case. By fixing the lid and the case body so that a fixed load is applied uniformly or almost uniformly over the entire circumference of the joint part, the mask blank stored in the case can be fixed firmly with a uniform fixed load, For example, generation of particles in the storage case can be suppressed by vibration during transportation and conveyance, and particle adhesion to the mask blank can be prevented. In addition, since it can be fixed so that a fixed load is applied uniformly or almost uniformly over the entire circumference of the joint between the lid and the case main body, the airtightness of the case can be improved and the entry of unstable outside air can be suppressed. Is possible.
Therefore, in the present invention, it is not necessary to simply remove foreign matters such as particles, and a chemically amplified resist film that needs to be stored in a particularly clean atmosphere is formed in order to eliminate the influence of contamination of chemical components. It is particularly suitable for storing mask blanks.

The fixing member used in 1st Embodiment of the storage case which concerns on this invention is shown, (a) and (b) are the top view and side view of a fixing frame, respectively, (c) and (d) are respectively It is the top view and side view of a fixed piece. (A) And (b) is a side view of the storage case of the state before fixing with the said fixing member, respectively. It is a side view of the storage case of the state fixed with the said fixing member. 2A shows a second embodiment of the storage case of the present invention, (a) a plan view in a state of being fixed by a fixing member, (b) a side view before being fixed by a fixing member, and (c) being fixed by a fixing member. FIG. 3A shows a third embodiment of the storage case of the present invention, (a) a plan view in a state of being fixed by a fixing member, (b) a side view of the state before being fixed by a fixing member, and (c) being fixed by a fixing member. FIG. It is a top view of the state fixed with the fixing member which shows 4th Embodiment of the storage case of this invention, (b) The side view of the state fixed with the fixing member. It is a perspective view which shows the cover of the storage case of conventional structure. It is a perspective view which shows the state which accommodates a mask blank in a middle case. It is a perspective view which shows the case main body (outer case) of the storage case of conventional structure.

The best mode for carrying out the present invention will be described below with reference to the drawings.
[First Embodiment]
1 to 3 show an embodiment of a storage case according to the present invention. FIG. 1 shows a fixing member used in this embodiment. (A) and (b) are a plan view and a side view of a fixing frame, respectively, and (c) and (d) are a plan view of a fixing piece, respectively. It is a side view. 2A and 2B are side views of the state before being fixed by the fixing member, and FIG. 3 is a side view of the state fixed by the fixing member.
The mask blank storage case according to the present embodiment is a mask blank storage case that includes a case main body 5 that opens upward and a lid 6 that covers the case main body 5 and stores the mask blank therein. . The overall shape of the case body 5 and the lid body 6 is that the storage case having the conventional structure is provided with the

concave portions

43 and 44 of the lid 4 and the

convex portions

33 and 34 of the case body 3. Has the same shape as the lid 4 shown in FIG. 7 and the case main body 3 shown in FIG. Although not shown in FIG. 1, a configuration using an intermediate case (see FIG. 8) for holding a plurality of mask blanks like the above-described storage case of the conventional structure can be adopted. Without using the middle case, the mask blank can be stored directly in the case body 5 with a groove or the like. However, if the middle case is used, several to several tens of mask blanks can be put together. It is convenient because it can be handled in the middle case 2.

In the storage case of the present embodiment, a mask blank in which a light-shielding thin film such as a chromium film is formed on one main surface of a glass substrate having a square main surface, and a resist film is formed on the light-shielding thin film is used as an intermediate case (not shown). 2), the inside case is housed in the case body 5, and the lid body 6 is put on the opening side of the case body 5 (see FIG. 2B). When the cover body 6 is put on the case body 5, the outer peripheral surface 61 following the lower edge of the cover body 6 and the opening edge portion 51 of the case main body 5 overlap each other at the same time, and at the same time, the outer peripheral surface of the lower edge of the cover body 6. 61 and the outer peripheral surface 52 below the opening edge portion 51 of the case body 5 overlap on the same surface, and the lid body 6 and the case body 5 are joined.

In the present embodiment, an annular elastic body 7 of an appropriate size is fitted along the opening edge 51 of the case body 5 in order to further improve the sealing performance of the storage case with the lid 6 closed. (FIG. 2 (b)). The elastic body 7 is preferably a material that emits less chemical component gas even when there are fluctuations in atmospheric temperature, pressure, etc., and examples thereof include polyolefin elastomers and polyester elastomers.

The storage case according to the present embodiment stores the mask blank inside as described above, and fixes the case body 5 and the lid body 6 in a state where the case body 5 is covered with the lid body 6. A fixing member is used that surrounds the entire periphery of the joint between the opening edge of the case body 5 and the lower edge of the lid 6 when the lid 6 is covered with the lid 6. The fixing member is preferably a belt-like member having a certain degree of flexibility and a predetermined width when fixing the case body 5 and the lid body 6, and a joint portion of the storage case The fixing frame 10 (see FIGS. 1A and 1B) formed in a substantially U shape in accordance with the outer shape of the fixing frame 11 and a fixing piece 11 that connects both ends of the fixing frame 10 (FIG. 1). (See (c) and (d)). The fixing frame 10 has hinge portions 10c so as to be expanded, and both end portions are provided with engaging

convex portions

10a and 10b at portions bent inward, respectively. The fixing piece 11 has engaging

recesses

11a and 11b that engage with the engaging

protrusions

10a and 10b of the fixing frame 10 at both ends thereof. The joint between the opening edge of the case body 5 and the lower edge of the lid body 6 when the case body 5 is covered with the lid body 6, that is, the outer peripheral surface 61 of the lower edge of the lid body 6 and the opening edge of the case body 5. The fixing frame 10 is fitted to a portion where the outer peripheral surface 52 below the portion 51 overlaps on the same plane, and the both ends of the fixing frame 10 are slightly pulled in the direction of approaching both ends of the fixing piece 11. The engagement

concave portions

11a and 11b are engaged with the engagement

convex portions

10a and 10b of the fixing frame 10 to tighten the joint portion. In the joint portion, at each taper portion (indicated by an arrow A in FIG. 2A) of the outer peripheral surface 61 of the lid body 6 and the outer peripheral surface 52 of the case body 5, the fixing frame 10 and the fixing piece 11 are connected. A fixed load due to tightening is applied inward, and the joint portion can be more firmly fixed. In the present embodiment, the lid body 6 and the case are engaged by engaging a fixing member that surrounds the entire circumference of the joint portion between the case body 5 and the lid body 6 when the case body 5 is thus covered with the lid body 6. The main body 5 is fixed (see FIG. 3).

According to such a mask blank storage case of the present embodiment, the mask blank is stored inside, and the case body 5 is covered with the lid body 6. By engaging the fixing member that surrounds the entire periphery, the joint portion between the opening edge of the case body and the lower edge of the cover body when the case body is covered with the cover body is tightened, The cover body and the case main body can be fixed so that a fixed load is applied uniformly over the mask, so that the mask blank stored in the case can be fixed firmly with a uniform fixed load, for example, vibration during transportation and transportation. Prevents the generation of particles due to rubbing between the mask blank in the storage case and the plastic parts that support it, and prevents particles from adhering to the mask blank. It is possible. Moreover, since it can fix so that fixed load may be applied uniformly over the perimeter of the junction part of a cover body and a case main body, the airtightness of a case can be improved and the approach of unstable external air can be prevented.

Moreover, in this Embodiment, when fixing the cover body 6 and the case main body 5 with the said fixing member, the outer peripheral surface 61 of the cover body 6 is pressed with a fixing member, the said elastic body 7 inside is crushed, The sealed state can be further increased. In this case, the storage case of the present embodiment can be fixed so that a fixed load is applied uniformly over the entire circumference of the joint portion between the lid body 6 and the case body 5, so that the case is airtight using the elastic body 7. Can be further increased. In addition, the mask blank stored in the case can be securely fixed even during transportation and transportation, and particle generation can be suppressed.
Therefore, in this embodiment, it is not necessary to simply remove foreign substances such as particles, and a chemically amplified resist film that needs to be stored in a particularly clean atmosphere in order to eliminate the influence of chemical component contamination. It is particularly suitable for storing the formed mask blank.

The materials of the case body 5 and the lid body 6 are, for example, polypropylene, acrylic, polyethylene, polycarbonate, polyester, polyamide, polyimide, polyethylsulfite, polybutylene terephthalate (PBT), acrylonitrile butadiene styrene (ABS). It is preferable to select appropriately from such resins. Among these, polycarbonate, polyester, and polybutylene terephthalate are preferable. In addition, if a charge is accumulated during the storage of the mask blank, a discharge breakdown may occur in the mask manufacturing process, resulting in a pattern defect. For example, carbon or the like is mixed into the constituent resin of the case body 5 to provide conductivity. You may do it.
The material of the above-mentioned fixing members (fixing frame 10 and fixing piece 11) is, for example, a resin such as polycarbonate, polyethylene, polypropylene, polybutylene terephthalate, acrylonitrile / butadiene / styrene (ABS), or a metal such as stainless steel or aluminum. Is preferably selected from the following.

[Second Embodiment]
FIG. 4 shows a second embodiment of the storage case of the present invention, (a) a plan view in a state of being fixed by a fixing member, (b) a side view of a state before being fixed by a fixing member, and (c) fixing. It is a side view of the state fixed with the member. In addition, the same code | symbol is attached | subjected to the location equivalent to above-mentioned FIG. 2, FIG.

The storage case according to the present embodiment stores the mask blank inside as described above, and fixes the case body 5 and the cover body 6 with the case body 5 covered with the cover body 6. Using the two fixing

members

8A and 8B that cover the top of the storage case, cover the four sides of the storage case. The fixing

members

8A and 8B are preferably flexible enough to be deformed so that the case body 5 and the lid body 6 can be covered from the upper part of the lid body 6 to the case body 5 when the case body 5 and the lid body 6 are fixed. The belt-shaped member has a predetermined width, and is formed in a substantially U shape in accordance with the outer shape of the storage case (see FIG. 4B). That is, each of the fixing

members

8A and 8B has

portions

81 and 83 having a length substantially corresponding to the height of the storage case with the lid 6 closed, and the lateral width of the storage case with the lid 6 closed. Is formed in a substantially U-shape having a portion 82 having a length substantially corresponding to the length. Then, both end portions of the fixing

members

8A and 8B have

portions

8a and 8b bent inward so as to be convenient for engaging with the bottom portion of the case body 5.

The widths of the fixing

members

8A and 8B are not particularly limited, but from the viewpoint of better exerting the effects of the present invention, the width L1 of the fixing

members

8A and 8B is set to the length L2 of one side of the case ( It is preferable to set it to 1/5 or more of FIG.4 (a), More preferably, it is 1/3 or more. Further, the widths of the fixing

members

8A and 8B do not necessarily match.
The material of the fixing

members

8A and 8B is preferably selected as appropriate from resins such as polycarbonate, polyethylene, polypropylene, polybutylene terephthalate, acrylonitrile butadiene styrene (ABS), and metals such as stainless steel and aluminum.

According to such a mask blank storage case of the present embodiment, the mask blank is stored inside, and the cover body is covered with the cover body 6 so that the fixing

members

8A and 8B intersect with each other. The cover 6 and the case body 5 are fixed by covering the four sides from the top of the cover 6 and engaging the both ends 8a and 8b of the fixing

members

8A and 8B with the bottom of the case body 5, respectively. As a result, the lid body and the case body are arranged so that a fixed load is applied uniformly over the entire circumference of the joint portion (matching portion) between the case body 5 and the lid body 6 when the case body 5 is covered with the lid body 6. The mask blank stored in the case can be fixed firmly with a uniform fixed load.For example, the mask blank in the storage case and the plastic parts that support it can be vibrated by vibration during transportation and transportation. Generation of particles due to rubbing against the mask blank can be suppressed, and adhesion of particles to the mask blank can be prevented. Moreover, since it can fix so that fixed load may be applied uniformly over the perimeter of the junction part of a cover body and a case main body, the airtightness of a case can be improved and the approach of unstable external air can be prevented.

Also in the present embodiment, when the lid 6 and the case body 5 are fixed by the fixing

members

8A and 8B, the outer peripheral surface 61 of the lid 6 is pressed by the fixing

members

8A and 8B, and the elastic body 7 inside By crushing, the sealed state in the case can be further enhanced. In this case, the storage case of the present embodiment can be fixed so that a fixed load is applied substantially uniformly over the entire circumference of the joint portion between the lid body 6 and the case body 5. The sex can be further enhanced.
Therefore, this embodiment is also suitable for storing a mask blank formed with a chemically amplified resist film that needs to be stored in a particularly clean atmosphere.
Further, in this embodiment, the two fixing members are used to fix the four sides of the storage case by increasing the width L1 of the fixing member and fixing the two sides of the storage case with only one fixing member. In addition, the lid body and the case body can be fixed so that a fixed load is applied substantially uniformly over the entire circumference of the joint portion between the case body 5 and the lid body 6 when the case body 5 is covered with the lid body 6. .

[Third Embodiment]
FIG. 5 shows a third embodiment of the storage case of the present invention, (a) a plan view in a state of being fixed by a fixing member, (b) a front view of a state before being fixed by a fixing member, and (c) fixing. It is a side view of the state fixed with the member. In addition, the same code | symbol is attached | subjected to the location equivalent to FIG.

In the storage case of the present embodiment, engaging convex portions 53 to 56 (56 is not shown) are provided on the outer side surfaces of the side walls of the case body 5 and below the outer peripheral surface 52 on the opening side. The engaging projections 53 and 56 of the case body 5 when the cover body 6 is covered with the case body 5, respectively, at both ends 9a and 9b of the two fixing

members

9A and 9B covered from the upper part of the cover body 6; The lid body 6 and the case main body 5 are fixed by being engaged with each other. The fixing

members

9A and 9B also preferably have flexibility that can be slightly deformed so that the case body 5 and the cover body 6 can be covered from the upper part of the cover body to the case body when the case body 5 and the cover body 6 are fixed. It is a band-shaped member having a width, and is formed in a substantially U shape in accordance with the outer shape of the storage case (see FIG. 5B). The material of the above-described

fixing members

9A and 9B is the same as that of the fixing

members

8A and 8B used in the second embodiment.

The widths of the fixing

members

9A and 9B need not be particularly limited. However, from the viewpoint of better exerting the operational effects of the present invention, the width of one side L2 of the case (see FIG. 4A) is reduced. It is preferably 5 or more, more preferably 1/3 or more.

That is, according to the mask blank storage case of the present embodiment, the mask blank is stored inside, and the cover body 6 is formed by crossing the

fixing members

9A and 9B in a state where the case body 5 is covered with the cover body 6. The cover body 6 and the case body 5 are attached to each other by engaging both

end portions

9a and 9b of the fixing

members

9A and 9B with the engagement convex portions 53 to 56 of the case body 5 respectively. Fix it. As a result, the lid body and the case body are arranged so that a fixed load is applied uniformly over the entire circumference of the joint portion (matching portion) between the case body 5 and the lid body 6 when the case body 5 is covered with the lid body 6. The mask blank stored in the case can be fixed firmly with a uniform fixed load.For example, the mask blank in the storage case and the plastic parts that support it can be vibrated by vibration during transportation and transportation. Generation of particles due to rubbing against the mask blank can be suppressed, and adhesion of particles to the mask blank can be prevented. Moreover, since it can fix so that fixed load may be applied uniformly over the perimeter of the junction part of a cover body and a case main body, the airtightness of a case can be improved and the approach of unstable external air can be prevented.

members

9A and 9B, the outer peripheral surface 61 of the lid 6 is pressed by the fixing

members

9A and 9B, and the elastic body 7 inside By crushing, the sealed state in the case can be further enhanced. In this case, the storage case of the present embodiment can be fixed so that a fixed load is applied uniformly over the entire circumference of the joint portion between the lid body 6 and the case body 5, so that the case is airtight using the elastic body 7. Can be further increased.

Therefore, this embodiment is also suitable for storing a mask blank formed with a chemically amplified resist film that needs to be stored in a particularly clean atmosphere.
For example, recesses are provided at both ends of the fixing

members

9A and 9B so that they can be engaged with the engaging protrusions 53 to 56 of the case body 5, and both ends of the fixing

members

9A and 9B are respectively connected to the case. You may make it engage with the engagement convex parts 53-56 of the main body 5. FIG.
Further, in this embodiment, the two fixing members are used to fix the four sides of the storage case by increasing the width L1 of the fixing member and fixing the two sides of the storage case with only one fixing member. In addition, the lid body and the case body can be fixed so that a fixed load is applied substantially uniformly over the entire circumference of the joint portion between the case body 5 and the lid body 6 when the case body 5 is covered with the lid body 6. .

[Fourth Embodiment]
6A and 6B show a storage case according to a fourth embodiment of the present invention, in which FIG. 6A is a plan view in a state of being fixed with a fixing member, and FIG.
The storage case according to the present embodiment is fixed so that a fixed load is uniformly applied over the entire circumference of the joint between the cover body of the storage case and the case body by covering the storage case with a plurality of fixing members per side. . That is, for example, it has the same shape as the fixing

members

8A and 8B used in the second embodiment described above, and is narrower than this, for example, about 1/10 to 1/5 of the length of one side of the case. The fixing

members

12A, 12B, 12C, and 12D having a width of 1 mm are used, and the fixing

members

12A and 12B are crossed on the left and right on one side of the case, and the fixing

members

12C and 12D are crossed on the left and right on the other side of the case. Then, the cover body 6 and the case body 5 are fixed by covering the cover body 6 in four directions from the top. In this embodiment as well, the fixed load is applied uniformly over the entire circumference of the joint (matching portion) between the case body 5 and the lid body 6 when the case body 5 is covered with the lid body 6. Since the lid and the case main body can be fixed, the mask blank stored in the case can be fixed firmly with a uniform fixed load, for example, the mask blank in the storage case and the It is possible to suppress the generation of particles due to rubbing with the plastic parts supporting the film and to prevent the particles from adhering to the mask blank. Moreover, since it can fix so that fixed load may be applied uniformly over the perimeter of the junction part of a cover body and a case main body, the airtightness of a case can be improved and the approach of unstable external air can be prevented.

The fixing members 12A to 12D have the same shape as the fixing

members

9A and 9B used in the third embodiment described above, and may be engaged with the same case body. In addition, FIG. 6 shows a mode in which the fixing member is put on two places per side of the storage case. However, depending on the size of the storage case, narrow fixing is performed at a plurality of places more than two places per side of the storage case. You may make it cover a member.

In the second to fourth embodiments described above, the lid 6 and the case main body 5 are fixed by engaging the fixing member that covers the upper portion of the lid 6 with the case main body 5. However, the present invention is not limited to this. For example, the upper fixing member covered from the upper side of the lid body 6 and the lower fixing member covered from the lower side of the case main body 5 are engaged (or fitted) with each other, thereby the lid body. 6 and the case body 5 may be fixed. Alternatively, the lid body 6 and the case body 5 may be fixed by engaging the lid body 6 with a fixing member that covers the lower portion of the case body 5. Also in such an embodiment, the two fixing members are used to fix the four sides of the storage case. The width of the fixing member is increased to fix the two sides of the storage case with only one fixing member. Even if the case body 5 is covered with the lid body 6, the lid body and the case body are fixed so that a fixed load is applied substantially uniformly over the entire circumference of the joint portion between the case body 5 and the lid body 6. Can do.

Hereinafter, the present invention will be described with reference to specific examples.
Example 1
A chromium film (light-shielding film) having an antireflection function is formed on the surface layer by sputtering on a synthetic quartz substrate (6 inches × 6 inches in size), and a positive chemically amplified resist is formed thereon by spin coating. A mask blank with a resist film was manufactured by forming a resist film for electron beam drawing.
The 25 mask blanks manufactured in this way were housed in a single case, and a total of 5 cases were prepared. As the storage case, the storage case according to the first embodiment shown in FIGS. 1 to 3 was used. The lid was made of acrylonitrile / butadiene / styrene (ABS), the case body was made of polypropylene, and the middle case was made of polypropylene. Further, polyethylene was used as the material of the fixing frame and the fixing piece, which are fixing members. Storage work was performed in a clean room.

The storage case (mask blank storage body) storing the mask blank was further packed with cardboard, and the following vibration test was performed.
In other words, after the packed storage case is first transported (traveling about 40 km on a general road with a private car), it is indoors and vibration accelerating treatment conforming to MIL-STD-810D of the US Military Standards MIL (Military Specifications and Military Standards) Went. The vibration conditions at this time were set assuming a general vehicle environment. Thereafter, the same transportation as described above was performed again.

After the vibration test, the storage case is also opened in the clean room, the mask blank is taken out of the storage case, and a defect (90 μm) due to adhered foreign matter on the mask blank main surface is detected using a defect inspection apparatus (Lasertec Corporation: M2350). The number of defects having the above size was measured. The evaluation was performed by measuring the number of defects before storage in the storage case in the same manner as described above and increasing the number of defects after the vibration test. As a result, in this embodiment, the number of increased defects is 1.8 on average for the mask blank stored in the approximate center position of the storage case, and 1 on average for the mask blank stored in the end position of the storage case. The number of mask blanks housed inside the case is fixed securely during transportation and transportation, and particle generation can be suppressed.

In addition, a predetermined electron beam drawing was performed on the mask blank taken out from the storage case after the vibration test, and then a predetermined development and etching were performed to prepare a transfer mask. The CD error (deviation of the measured line width with respect to the designed line width) of the formed light shielding film pattern was as small as 5 nm or less, and a highly accurate fine pattern could be formed using a chemically amplified resist.

(Example 2)
In this example, as the case for storing the mask blank manufactured in the same manner as in Example 1, the case similar to Example 1 was used except that the storage case according to the second embodiment shown in FIG. 4 was used. The mask blank was stored. The fixing member was made of polyethylene.

A storage case (mask blank storage body) storing the mask blank was packed, and a vibration test similar to that of Example 1 was performed.
In the same manner as in Example 1, the number of defects increased after the vibration test with respect to the number of defects before being stored in the storage case was measured. As a result, in this embodiment, the number of increased defects is 1.8 on average for the mask blank stored in the approximate center position of the storage case, and 1 on average for the mask blank stored in the end position of the storage case. The number of mask blanks housed inside the case is fixed securely during transportation and transportation, and particle generation can be suppressed.

Further, a transfer mask was produced in the same manner as in Example 1 using the mask blank taken out from the storage case after the vibration test. The CD error (deviation of the measured line width with respect to the designed line width) of the formed light shielding film pattern was as small as 5 nm or less, and a highly accurate fine pattern could be formed using a chemically amplified resist.

(Comparative example)
The mask blank was stored in the same manner as in Example 1 except that the conventional storage case shown in FIGS. 7 to 9 was used as a case for storing the mask blank manufactured in the same manner as in Example 1. . The material of the storage case lid, middle case, and case main body was the same as that of the storage case of Example 1.

A storage case (mask blank storage body) storing the mask blank was packed, and a vibration test similar to that of Example 1 was performed.
In the same manner as in Example 1, the number of defects increased after the vibration test with respect to the number of defects before being stored in the storage case was measured. As a result, in this comparative example, the number of increased defects is 2.0 on the average for the mask blank stored in the approximate center of the storage case, and 11 on the average for the mask blank stored at the end of the storage case. The number of defects in the mask blank stored at the edge of the storage case was particularly large. In the case of the storage case having the conventional structure, the fixed load on the mask blank is weak at the end of the case away from the fixing position by the hook structure, and it is considered that the generation of particles due to rubbing is a factor.

Further, after the above vibration test, a transfer mask was produced in the same manner as in Example 1 using a mask blank taken out from the central position of the storage case. The CD error (deviation of the measured line width with respect to the designed line width) of the formed light shielding film pattern was as large as 10 nm. This is because, in the case of a storage case with a conventional structure, the airtightness is insufficient, and outside air enters the case from the joint of the storage case during transportation, and the chemically amplified resist is contaminated by some chemical component or the like. It is thought to be the cause.

DESCRIPTION OF SYMBOLS 1 Mask blank 2 Middle case 3 Case main body 4 Lid 5 Case main body 6 Lid 7

Elastic body

8A, 8B, 9A, 9B Fixing member 10 Fixing frame 11

Fixing piece

12A, 12B, 12C, 12D Fixing member

Claims

A mask blank storage case that includes a case main body that is open at the top and a lid that covers the case main body, and stores the mask blank therein, and the case main body by a fixing member that engages with the storage case. The lid body and the case body are arranged so that a fixed load is applied uniformly or substantially uniformly over the entire circumference of the joint portion between the opening edge of the case body and the lower edge of the lid body when the lid is covered with the lid body. Mask blank storage case, which is fixed.
By engaging a fixing member that surrounds the entire circumference of the joint portion between the opening edge of the case body and the lower edge of the lid when the lid is put on the case body, the lid and the case The mask blank storage case according to claim 1, wherein the mask blank storage case is fixed to the main body.
The mask blank storage case according to claim 1, wherein the cover body and the case main body are fixed by covering the case main body with a fixing member on four sides of the storage case when the cover body is covered. .
The mask blank storage case according to claim 3, wherein the fixing member is covered at a plurality of locations per side of the storage case.
An elastic body is provided around at least one of the opening edge of the case body or the lower edge of the lid, and the opening edge of the case body and the lower edge of the lid when the case body is covered with the lid The mask blank storage case according to any one of claims 1 to 4, wherein the elastic body is interposed in a joint portion with the portion.
A mask blank storage method, wherein a mask blank having a resist film is stored in the mask blank storage case according to any one of claims 1 to 5.
The mask blank storing method according to claim 6, wherein the resist is a chemically amplified resist.
A mask blank housing body in which a mask blank is housed by the housing method according to claim 6 or 7.