KR20070039910A - Mask blank, manufacturing method thereof and transfer plate manufacturing method - Google Patents

Abstract

This prevents the possibility of causing a problem by attaching foreign matter directly to the surface of the mask during the manufacturing process of the mask blank or the mask, or during storage, transportation and transportation. On the mask blank main surface of the side on which the mask function thin film and / or the thin film used for the mask manufacturing process are formed, a cover shape which does not contact an effective area where a mask pattern is formed but contacts an invalid area to form a closed space Securing the dust protection device detachably.

Mask Blank, Foreign Material, Mask Pattern, Dust Protector

Description

MASK BLANK, MANUFACTURING METHOD THEREOF AND TRANSFER PLATE MANUFACTURING METHOD}

This invention relates to the mask blank which is a raw material of a mask and a stamper for pattern transfer, its manufacturing method, and the manufacturing method of a transfer plate.

The mask blank is used as a material for a pattern transfer mask of the photolithography method or a stamper of the nanoimprint method. In the case of the pattern transfer mask, for example, a resist film is formed on various mask function thin films formed on the substrate surface, or an antireflection film or a conductive film is formed on or under the resist film, or these thin film masks A protective film or the like is formed to protect it from the surrounding environment (for example, chemical pollution). In the case of the stamper of the nanoinprint method, for example, a thin film, i.e., a mask layer and / or a resist film, used in a mask manufacturing process for forming fine irregularities on the substrate surface is formed.

As a specific example of the said mask blank, the mask blank with a resist whose uppermost layer is a resist film is attached. After the mask blank with the resist is formed with various mask functions thin films or the like on the substrate surface, a resist film is applied thereon by a rotation coating method or the like, and thereafter, predetermined resists such as heat treatment (including subsequent cooling treatment) are applied. Treatment is carried out to form.

As the mask function thin film formed on the surface of the substrate, a light shielding film, a phase shift film (in the case of a phase shift mask), a reflecting film or an absorbing film (in the case of an X-ray mask or an EUV mask), an antireflection film, etc., depending on the kind and use of the mask, etc. There is this. These thin films are intended to form a predetermined transfer pattern image on the transfer object by any action on the transfer exposure light, such as passing the transfer exposure light, preventing passage, or reflecting it.

The mask blank with the resist is formed by sequentially forming a light shielding film and an antireflection film on a substrate such as synthetic quartz by sputtering or the like, and applying the resist thereon by a spin coating method or the like. In the resist film formed in this way, an unnecessary convex part arises in the edge part (part along four sides of the main surface of a board | substrate) of a board | substrate, and an unnecessary resist is formed in the side surface of the board | substrate in many cases.

In general, however, the mask blank with the resist is stored in a storage container or the like at the time of conveyance or storage. As this storage container, the same thing as the glass substrate storage container of patent document 1 is used, for example. The storage container of patent document 1 consists of an inner box and the outer container which accommodates this inner box. On the inner wall of the inner box, a pair of opposing receiving grooves which slide and guide the edges of both sides of the substrate while being held and positioned are arranged at regular intervals. The outer box holds and secures the inner box.

However, as mentioned above, in the mask blank with a resist, an unnecessary convex part arises at the edge part, and unnecessary resist is formed also in the side surface of the board | substrate. For this reason, when the mask blank with the resist is stored in the inner box or extracted therefrom, it is inevitable that the unnecessary convex portions or unnecessary resists come into contact with the storage grooves and rub. In addition, even when held in the storage groove, when vibrations or impacts are applied by transportation, transportation or the like, the unnecessary convex portions and unnecessary resists cannot avoid rubbing with the storage grooves of the inner box.

As a result, unnecessary convex portions and unnecessary resists are peeled off and dropped off from the substrate, which becomes dust and adheres to the mask blank itself or various processing apparatuses. Finally, the mask (including the reticle) which is a product made of the mask blank as a material There exists a possibility that it may become a cause of a defect or the fall of the manufacturing yield of a mask.

As a solution of the above problem, a method of selectively removing an unnecessary resist film formed on an edge portion of a substrate is generally employed. In this method, the unnecessary resist film of a board | substrate edge part is removed selectively after resist coating (for example, refer patent document 2, patent document 3, patent document 4).

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-264225

Patent Document 2: Japanese Patent Application Publication No. 57-13863

Patent Document 3: Japanese Patent Application Laid-Open No. 63-160332

Patent Document 4: Japanese Unexamined Patent Publication No. 2001-259502

However, even when it is a mask blank by which the unnecessary resist film of the board | substrate edge part was selectively removed by the said method etc., it turned out that there exists a following problem. That is, in the storage container described, for example, in patent document 1, the mask blank cannot be in direct contact with the inner box or the like partially, and the grazing, storage or transporting when the mask blank is accommodated in or taken out of the storage container. The occurrence of grazing can be thought of in many places, such as the grading of the contact area between the mask blank and the center box and the grazing of the contact area between the center box and the outer box due to the vibration or impact during transportation. In addition, dust generation by grazing occurs not only on the mask blank side but also on the storage container side. Especially in the storage container made of resin, this container is a cause of a big dust generation.

It is extremely difficult to suppress the cause of all these dusts (particularly the generation of dust from the resin container). For this reason, foreign matters that may adhere to, or possibly adhere to, foreign matters on the surface of the mask blank, that is, on the resist film or the top surface layer formed on the resist film during the storage, storage, or transfer and transportation of the mask blank. It was found that it was very difficult to effectively prevent the increase of the.

Moreover, when mask manufacture is performed using said mask blank with a resist, the elapsed time (or days) from a resist application to the exposure process in a mask manufacturing process is various. The variation in the elapsed time and the number of days until the exposure process affects the variation in the variation in resist sensitivity, and when the resist process (so-called patterning) conditions such as exposure and development are fixed, the variation in the elapsed time or the like pattern It appears with the change of the dimension CD. For this reason, as the resist film formed on the mask blank, a resist type excellent in post-coating stability with a small change in sensitivity after application, and a good resist type of so-called post-coating stability (PCD) is selected and used as much as possible. do.

In the chemically amplified resists that are widely used today, as a resist having good stability after application, an additive (for example, amines) commonly called a quencher is intentionally added. However, this quencher improves the stability after application and cannot raise the resist sensitivity to a certain degree or more, and therefore, a limitation arises in selecting the resist for mask blanks or the resist design.

However, in view of exposure productivity, that is, mask productivity and exposure stability, it is preferable that the resist sensitivity is high. In the case of exposure by an electron beam, although the sensitivity of a resist may fluctuate by the resist heating which arises by the electron beam exposure, it is preferable that this variation is as small as possible. That is, it is preferable to have to-be-exposed stability.

In addition, in a situation where pattern refinement or narrow pitch is required, there is a problem in the amount of deterioration or variation in resist sensitivity caused by the elapsed time or the number of days from the application of the resist to the exposure process (that is, the storage period after the application). It is becoming.

That is, conventionally, the amount of change in resist sensitivity after application, which has been permitted, does not correspond to the sensitivity stability necessary to achieve high level miniaturization. For this reason, it is preferable to perform formation of a resist film immediately before the exposure process in a mask manufacturing process. However, when the mask blank in which the mask function thin film which optically acts on transfer exposure light is formed in the board | substrate surface is accommodated in said storage container, and conveyed, transported, or stored in a mask manufacturing process, it is a mask blank (optically acting on transfer exposure light). The deposition of foreign matter or chemical contaminants on the surface affects the quality or performance expression of the resist film applied and formed immediately before the exposure process in the mask manufacturing process. Or lower the manufacturing yield of the mask.

[Means for solving the problem]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and during storage, conveyance or transportation of the mask blank during the time from the manufacture of the mask blank (after forming the top layer or after the final inspection) to the exposure step of the manufacturing process of the transfer plate such as the mask. In addition, the present invention provides a mask blank, a method of manufacturing the same, and a method of manufacturing the transfer plate, which can effectively prevent a possibility of causing a problem by attaching foreign matter to a substrate or the like.

The summary is as follows, as described in the claim.

That is, as a means for solving the above problem,

The first means is

A mask blank, which is a material of a pattern transfer mask or stamper, having a mask function thin film and / or a thin film used in a mask fabrication process optically acting on the transfer exposure light on the substrate surface;

The mask blank does not contact a mask pattern for pattern transfer or an effective region in which irregularities for pattern transfer are formed on the mask blank main surface on the side where the mask function thin film and / or the thin film used in the mask manufacturing process are formed. The mask blank is fixed so as to be able to separate the cover-shaped dustproof protective device which contacts the ineffective area and forms a closed space.

According to this solution, the mask blank by putting the mask blank into and out of the storage container, the mask blank by the vibration or impact when storing, moving or transporting the grazing and mask blank at the contact portion of the storage container into the storage container, The grazing with the storage container or the like and the grazing of the contact portions between the respective constituent members of the storage container, and dust generated due to them are prevented from directly adhering to the mask blank itself.

In addition, by separating the dust protection protection prior to the exposure process, which is a major first step of the mask manufacturing process, dust attached to the surface of the protection protection after dust protection is removed, thereby preventing an increase in surface defects (foreign matter) of the mask blank. The quality immediately after completion of the mask blank can be provided to the mask fabrication process, and a means for preventing the occurrence of mask defects due to the surface defects (foreign matters) and providing a means for improving the yield of mask fabrication. In addition, by using a constituent material that does not affect the resist film (e.g., less alkali or acid gas emission), the anti-vibration protective pattern is formed by patterning the mask without deteriorating the function of the resist film by attaching the anti-vibration protective device. A large pattern can be formed to produce a mask.

Second means,

A mask blank according to said first means,

The dust protection device, the mask blank surface,

It is a mask blank characterized by being fixed using any of the thermoplastic adhesives which have adhesiveness in vacuum adsorption | suction, a suction sheet, or normal temperature, and when it heats, adhesiveness falls or loses.

According to this solution, the dustproof protective equipment can be securely mounted and fixed to the mask blank, and the separation of the dustproof protective equipment can also be safely and easily performed without damaging the mask blank. In addition, since there is no need to use an adhesive or the like, there is no worry of remaining of the adhesive or the like after removing the dustproof protective device, and it does not cause a new dust generation source. In addition, since there is no need to use an adhesive or the like, it is possible to exclude the possibility of releasing a chemical (gas) from the adhesive which causes deterioration of the resist film.

In addition, the second means,

A mask blank according to said first means,

The antivibration protective device is a mask blank, which is provided with a suction plate at the bottom contacting the mask blank surface, and is fixed to the mask blank surface.

According to this solution, the equipment necessary for the vacuum adsorption method which is said means is unnecessary. In particular, it is not necessary to attach a connection part or a stop valve to the dustproof protector, so that the dustproof protector can be easily attached and detached. This means also eliminates the need for adhesives, thus eliminating the possibility of release of chemicals that cause performance degradation of the resist film. What is necessary is just to select beforehand the resin material which comprises the sucker sheet which is this means which does not contain the chemical substance which causes deterioration of the resist film.

In addition, the second means,

A mask blank according to said first means,

The antivibration protective device is a mask blank, which is fixed to a mask blank surface by a thermoplastic adhesive which has adhesiveness at normal temperature and which loses or loses adhesiveness when heated.

According to this solution, the equipment necessary for the vacuum adsorption method which is said means is unnecessary. In particular, it is not necessary to attach a connection part or a stop valve to the dustproof protector, so that the dustproof protector can be easily attached and detached. In addition, compared to the means using the sucker sheet, when the dustproof protective device is removed, since it requires little mechanical force to pull the dustproof protective device and peel off the sucker of the sucker sheet, the dustproof protective device is very safe and easy. Can be separated.

In particular, heat treatment using a hot plate type heat treatment apparatus which is widely used in the mask manufacturing process is possible, and the anti-vibration protective equipment fixed to the mask blank by the function of the adhesive (degradation of adhesiveness by heating) It can be separated.

Third means,

A mask blank according to the second means,

The thermoplastic adhesive is a mask blank, characterized in that the dustproof protective device can be peeled off from the mask blank surface at a temperature higher than normal temperature and lower than the heat treatment temperature after formation of the resist film.

According to this solution, the equipment necessary for the vacuum adsorption method, which is the second means, is unnecessary, and in comparison with the third means, a machine for pulling the dustproof protector off and removing the sucker of the sucker sheet when the dustproof protector is removed. It requires very little power, making it very easy to remove the dust protection device.

According to this solution, a heat treatment temperature (pre-baking temperature) after application of the resist film formed on the mask blank or a heat treatment temperature after exposure is used as a temperature at which the adhesion decreases to the thermoplastic adhesive whose adhesiveness decreases when heated. By using an adhesive having a lower temperature than any one of the lower PEB temperatures, it is possible to minimize the influence of the heat treatment for the separation of the dustproof protector against the resist film (change in sensitivity, decrease in film thickness, etc.). have.

The fourth means,

A mask blank according to said first means,

The dust protection device is a mask blank, characterized in that the surface opposite to the mask blank surface is transparent to visible light or inspection light.

According to this solution, it is possible to visually observe the inside of the airtight space (that is, the mask blank surface) formed by the dustproof protective equipment and the mask blank, and the inspection apparatus can be used to inspect the laser surface foreign matter with the dustproof protective equipment mounted thereon. The number of foreign substances on the mask blank surface can be counted. This enables inspection of the mask blank surface state after the antivibration protective equipment is attached or before separation.

The fifth means is

A mask blank according to any one of the first to fourth means,

The mask blank is characterized in that the resist film on the surface of the substrate to which the dustproof protective equipment contacts is removed.

According to this solution, since the film which easily peels off, such as a resist film, is removed in the contact part of the mask blank which a dust protection protective tool contacts, the contact or grazing of the dust protection and mask blank at the time of attachment or detachment of a dust protection protection is performed. It is possible to exclude the occurrence of dust. In addition, by removing an unnecessary resist film or the like from the mask blank substrate edge and the mask blank contact portion where the dust protection protection contacts, the occurrence of dust due to the contact or masking between the mask blank and the storage container can be suppressed. In addition, the possibility of contamination of the mask blank surface, in which dust generated at the time of mounting or detachment of the dustproof protector directly adheres to the mask blank surface, can be reduced.

Sixth means,

In the mask blank manufacturing method which manufactures the mask blank which is a material of a pattern transfer mask or a stamper in which the mask function thin film which acts optically on a transfer exposure light, and / or the thin film used for a mask manufacturing process was formed in the substrate surface,

A thin film forming step of forming a mask function thin film optically acting on the transfer exposure light and / or a thin film used in a mask manufacturing process on the substrate surface;

On the mask blank main surface of the side on which the said mask function thin film and / or the thin film used for a mask manufacturing process were formed, it does not contact the mask pattern for pattern transfer or the effective area | region where the unevenness | corrugation for pattern transfer is formed, and is invalid It is a mask blank manufacturing method characterized by having a dustproof fitting installation process which mounts the cover-shaped dustproof protective apparatus which contacts a region and forms a sealed space.

By this solution, the mask blank and the storage container caused by the dust generated by both grazing when the mask blank is taken in and out of the storage container and the vibration or impact when the mask blank is stored, moved or transported in the storage container or Dust generation due to grazing between the respective constituent members of the storage container and foreign matter contamination (increase of foreign matter) to the mask blanks (that is, the top layer surfaces of various thin films formed on the mask blanks) are greatly reduced. That is, the mask blank manufacturing method which makes it possible to supply the quality (foreign | defective defect quality) immediately after mask blank manufacture to a mask manufacturing process is provided.

Seventh means,

In the mask manufacturing method which has a mask pattern formation process which forms the mask pattern for pattern transfer in the mask blank which is a raw material of the pattern transfer mask,

The mask pattern formation is performed after using the mask blank described in any one of the said means 1-5, after isolate | separating the said dustproof protective tool of this mask blank.

By this solution, the mask blank and the storage container caused by the dust generated by both grazing when the mask blank is taken in and out of the storage container and the vibration or impact when the mask blank is stored, moved or transported in the storage container or Dust generation due to grazing between the respective constituent members of the storage container and foreign matter contamination (increase of foreign matter) to the mask blanks (that is, the top layer surfaces of various thin films formed on the mask blanks) are greatly reduced. That is, the mask manufacturing process which can hold | maintain and ensure the quality (foreign | defective defect quality) immediately after mask blank manufacture is provided. Furthermore, the mask manufacturing method which prevents generation | occurrence | production of the mask defect resulting from a foreign material contamination (increase of a foreign material) to the mask blank (namely, the uppermost surface of the various thin films formed in the mask blank) after mask blank manufacture, and prevents the fall of mask manufacturing yield. This is provided.

Here, the mask blank in the present invention is used in a broad sense, wherein a light shielding film having a function of shielding transfer exposure light is formed, and a phase shift film having a function of causing a phase difference change with respect to the transfer exposure light. Formed, a halftone phase shift film of a light semitransmissive film having a light shielding function with respect to transfer exposure light and a function of causing a phase difference change, a reflection film having a function of reflecting transfer exposure light, and absorbing transfer exposure light An absorption film having a function of suppressing reflection is formed, or the like, or a laminate film thereof is formed, including any functional film or a laminate film thereof required to constitute a function of the transmissive and reflective mask. Or applying resist to them, and also reflecting on or under the resist film The prevention film, the conductive film formed by laminating | stacking alone or laminated | stacked, and the thing which provided the environmentally protective film on the resist film or the laminated film containing a resist film were formed. Moreover, these films do not need to be formed.

In addition, the mask blank in this invention contains the original plate used for the chromeless mask, the stamper used for nanoinprint technology, etc. This original plate is formed with a thin film, that is, a mask layer and / or a resist film, used in a mask manufacturing process for forming fine irregularities on a substrate surface on a substrate. The mask layer may be a single layer film or a laminated film formed of a plurality of layers. In addition, it is preferable that the material of a mask layer is a material which has the etching selectivity more than predetermined with respect to the board | substrate etc. which are under a mask layer.

The mask blank includes materials of all masks, such as a mask blank for LSI (semiconductor circuit) and a mask blank for various PD (panel display). The material of the substrate is not particularly limited. Synthetic quartz glass, alkali free glass, borosilicate glass, aluminosilicate glass and soda lime glass are generally used as the transparent substrate. As the substrate material for the reflective mask, ultra low expansion glass or ultra low expansion ceramic is used.

The thin film formed on the substrate surface includes a light shielding film, a phase shift film (in the case of a phase shift mask), a reflecting film or an absorbing film (in the case of an X-ray mask or an EUV mask), an antireflection film, or the like depending on the type of mask. These thin films are intended to form a predetermined transfer pattern image on the transfer object by performing any action on the transfer exposure light, such as passing or preventing passage of the transfer exposure light. Also included are thin films used in the mask manufacturing process, for example, resist films.

The resist may be either negative or positive. Moreover, resist species are not specifically limited, either. Light (ultraviolet rays, far ultraviolet rays, etc.) exposure drawing, electron beam exposure drawing, etc. may be used. The formation method of a resist is not specifically limited, either. Rotary coating, Capillary coating, Scan coating, etc. can be anything.

In the present invention, the anti-vibration protective device does not contact an effective area where a mask pattern is formed on the mask blank main surface, but forms an airtight space by contacting an invalid area, that is, a thin film of the resist film or the like in the effective area. If it is a cover shape which does not directly contact a back and does not damage, it does not prescribe the shape and may be anything.

In the present invention, the sealed space is not limited to being completely blocked from the environment to be transported, transported, or stored. The sealed space may be a closed space such that foreign substances, scientific contaminants, and the like are not adhered to the mask blank main surface.

In addition, the dustproof protective equipment is separated, for example, immediately before the use of the mask blank, that is, prior to the resist exposure process, which is the first main process of the mask manufacturing process. In addition, in such a case, a resist is applied immediately before the resist exposure step of the mask manufacturing step or a thin film used in a mask manufacturing process such as an antireflection film and / or an antistatic film is applied. First, remove the dust protection.

Therefore, the effect is that the mask blank is placed in the storage container, transferred, transported or stored immediately after formation of the uppermost layer in the mask blank manufacturing process, and then the mask blank is extracted from the storage container and held until just before use. do. In addition, the material composition of the dustproof protective device has no effect on the function or quality of the mask function film or the resist film used in the mask manufacturing process or the mask manufacturing process, which optically acts on the mask blank or the transfer exposure light. Is selected.

[Effects of the Invention]

During the manufacturing process of the mask blank or transfer plate (mask or stamper), or during storage and transport of the mask blank, foreign matter is directly in the mask area for pattern transfer on the main surface of the mask blank, or in an effective area where irregularities for pattern transfer are formed. It effectively prevents the possibility of causing a problem by being attached.

Best Mode for Carrying Out the Invention

1 and 2 are explanatory views of a method of manufacturing a mask blank and a method of manufacturing a mask according to an embodiment of the present invention. Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1A to 2F and 2F to j.

(First embodiment)

First, a mask blank is manufactured by the conventional method. 45 nm thick on a substrate 1 (FIG. 1 (a)) made of synthetic quartz glass having a thickness of 152.4 mm X 152.4 mm and suitably polished, as shown in FIG. Was formed by the sputtering method, and then on the light shielding film 2, an antireflection film 3 having a thickness of 25 nm containing chromium oxide as a main component was formed by the sputtering method.

Next, as shown in Fig. 1 (c), on the antireflection film 3, the resist film 4 (positive chemically amplified electron beam drawing exposure resist FEP171: FUJIFILM arch yarn) has a film thickness after heat-drying treatment of 400 nm. Product) was applied by rotation. Next, as shown in Fig. 1 (d), the unnecessary resist film formed at the edge of the substrate 1 was removed.

In this case, the removal of unnecessary resist is performed by using a well-known unnecessary film removal apparatus (for example, the apparatus described in Patent Document 5) and using an organic solvent as a solvent to remove an unnecessary resist film (about 3 mm from the substrate end). Dissolution removal). After dissolving and removing the unnecessary resist film, a heat-drying treatment after applying the resist was performed for 10 minutes using a hot plate set at 150 ° C. (proxymetic gap = 0.2 mm) to prepare a mask blank 101 with a resist.

Thereafter, the number of foreign matter defects on the main surface of the mask blank was measured by a laser scanning foreign matter inspection device (GM-1000, manufactured by Hitachi Electronics Engineer Co., Ltd.). This measurement counts the number of foreign matters (size 0.25 mu m or more) on the surface of the effective area 142 mm angle (substrate center) of the mask blank.

Next, as shown in FIG. 1 (e), the dustproof protective equipment 5 was attached.

Here, the shape of the anti-vibration protective device 5 is specifically a cover shape covering the main surface of the mask blank 101 with a resist, as shown in FIG. It has a horizontal flat part (square top plate), and it bends substantially vertically downward at all the edge parts (four sides of the said square plate), and the side wall part is formed.

When the antivibration protective equipment 5 is mounted on the main surface of the mask blank 101 with a resist, a seal member such as an O-ring or a gasket for forming a groove in the bottom of the side wall of the antivibration protective equipment to maintain a fixed airtightness ( 11) a portion in contact with the ineffective area (region outside the center of the substrate 142 mm) of the main surface of the mask blank 101 to which the resist is attached, and removing the bottom of the side wall portion is an effective area of the mask blank (center of the substrate). It is a structure which forms a closed space so that it may not directly contact a 142 mm square area | region.

In addition, the tube 13 is connected to the center of the flat part (top plate) of the anti-vibration protective device 5 through the connecting part 12, and in front of the tube 13 connected to the flat part (the ceiling plate) of the anti-vibration protective device. On the opposite end), a normally closed stop valve 14 (in this example, an air operated type) is arranged, and the vacuum pump 15 (from the stop valve 14 through another tube 13) ( Diaphragm type dry pump). Specifically, the dustproof protective device 5 is formed of a PEEX (polyether ether ketone) material with a lid shape of FIG. Dust protection.

The antivibration protective equipment 5 was fixed as follows.

As described above, after counting the number of foreign matter defects on the main surface with a laser scanning foreign matter inspection device, the mask blank 101 with a resist is fixed to the fixing jig (for example, a vacuum chuck) with the main surface upward. Subsequently, the center of the dustproof protective part 5 and the mask blank 101 with a resist were aligned, and the dustproof protective part 5 was placed on the main surface of the mask blank 101 with a resist. In this case, the contact portion between the dustproof protective member 5 and the mask blank 101 is, as described above, a portion from which an unnecessary resist film has been previously removed (chromium oxide film has been exposed) and an O-ring disposed at the bottom of the sidewall portion of the dustproof protective equipment. It is a seal material 11.

Next, the vacuum pump 15 is operated in a state where the normally closed stop valve 14 is opened (operated), and the normally closed stop valve 14 is closed (stopped operation) at a place where a predetermined decompression pressure is reached. The tube 13 and the vacuum pump 15 in front of the stop valve 14 were separated. By the sealed pressure-reduced space formed by the above operation, the dustproof protector 5 is vacuum-adsorbed to the mask blank 101, and the photomask blank 102 with the dustproof protector of the present invention is completed.

In this step, the mask blank 102 (FIG. 1 (e)) with the obtained dustproof protective equipment was put into a storage container. A storage container consists of an outer box and an intermediate box, and a storage groove is formed in the center box (for example, refer patent document 1). This middle box was accommodated in a predetermined holding state in the outer box. Cover the lid of this outer box, fix it with vinyl tape, put it in a resin bag, heat seal it to prevent foreign material from invading from the outside, and then use a packing material made of foamed styrol and a transport package made of cardboard. The packing for transportation comprised of the box was performed, the transfer of the mask blank was assumed, and the vibration test process was performed. This vibration test is a vibration test process according to "the process in the general vehicle environment of MIL STD-81OD 514 * 3 (but it processes in three directions of XYZ at twice the acceleration)".

Next, assuming the storage of the mask blank, after the vibration test treatment, the storage container containing the mask blank was extracted from the packing for transportation, put in a resin bag and heat sealed for 30 days in a state of being heat sealed. And left in a humidity-controlled clean room (above, mask blank transport and storage in the form shown in FIG. 2 (f)).

Next, the mask blank 102 with the dustproof protective device after the storage was extracted from the storage container, and the dustproof protective device 5 was separated. Specifically, the closed space is returned to normal pressure by opening (operating) the normally closed stop valve 14 which is closed after the decompression treatment in order to be connected to the top plate of the dustproof protective device 5 to form a reduced pressure sealed space. The dustproof protector 5 is opened from the fixed state and becomes detachable. In reality, the air supplied by opening of the normally closed stop valve 14 in order to return the above-mentioned closed pressure reducing space to the normal pressure is transferred to the stop valve 14 (by a separate tube 13 via a filter) ( That is, it supplied to the said sealed space.

After removing the dustproof protector 5 from the mask blank 102 with the dustproof protector (FIG. 1 (g)), the number of foreign matters on the surface of the mask blank was again measured by the laser scanning foreign matter inspection device, and the vibration test treatment was performed. The increase (difference) of foreign matters before and after was obtained.

As a result, the number of increase of the foreign matter was 0.2, which was very small, and was the same value for the measurement reproduction performance of the laser scanning foreign matter inspection apparatus. In this case, the increase number of the foreign matter used the average value of the foreign material increase of the five mask blanks put into the storage container.

As a comparison, the increase (difference) of foreign matters before and after the vibration test treatment under the same conditions except that the anti-vibration protective equipment 5 was not attached was found to be 68. Incidentally, when the anti-vibration protective film was not provided and the unnecessary resist film of the mask blank edge portion was not removed beforehand, the increase in foreign matter was 284 in the same manner.

Next, as shown in FIG.2 (h), the resist film 4 was subjected to pattern exposure, post-exposure bake treatment, and then developed to form a resist pattern 4a. Here, exposure, post-exposure bake and development of the resist film 4 were performed as follows. That is, the resist film 4 (the said FEP171) is exposed by an electron beam exposure apparatus (acceleration voltage 20kV, exposure amount 3.5 microC / cm <^2> ), after exposure, heat processing (PEB: post-exposure bake treatment, 150 degreeC, 10 Powder treatment) and development treatment (spray method, 2.38% TMAH developer, 60 second treatment) to form a resist pattern 4a.

The measurement of the dimension of the space part of the resist pattern 4a (line-and-space pattern of 400 nm of design value) formed in this way by the measurement SEM was 414 nm. On the other hand, as a comparative example, in the mask blank produced without using the dustproof protective equipment, the dimension of the space portion of the line and space pattern with a design value of 400 nm completed by patterning the resist film under the same conditions as described above is 411 nm.

The difference in dimensions (3 nm) in the space portion of both line and space patterns is less than or equal to the range of the error resulting from the stability of the patterning process including the measuring means used, and therefore, the resist by employing the dustproof protective equipment. It was judged that there was no influence of the performance of the membrane.

Subsequently, an etching process is performed on the mask function film (the antireflection film 3 and the light shielding film 2) (FIG. 2 (i)), and finally, the resist pattern 4a is peeled off to remove the mask (reticle) ( 103 (FIG. 2 (j)) is complete. In the mask inspection apparatus, when a mask pattern was inspected, a mask created using a mask blank provided with a dustproof protective device did not have a pattern defect, but a pattern defect occurred in a mask created using a mask blank without a dustproof protective device. In particular, much has been found about not removing the unnecessary resist film of the mask blank edge part.

Here, in the above embodiment, as the mounting fixing means of the dustproof protector, the sealed space formed by the seal member embedded in the groove of the side wall bottom of the dustproof protector and the stop valve is reduced by a vacuum pump connected thereto to form a reduced pressure sealed space. Although the vacuum adsorption method was used, it is not limited to this structural means. For example, the following embodiments are effective.

(2nd Example)

As a separate means for attaching and fixing the dustproof protector to the mask blank using a vacuum adsorption method using a vacuum decompression space, specifically, to maintain the airtightness embedded in the groove of the side wall bottom of the dustproof protector, as shown in FIG. After opening (operating) the normally closed stop valve by using a space formed by a seal member 11 such as an O-ring or a gasket and a normally closed stop valve 14 installed on a top plate, the above dustproof protective device is provided. The mask blank is placed in the vacuum hermetic chamber 16, and the vacuum pump 15 connected thereto is operated to depressurize, and then the closed valve 14 is normally closed (stopped operation), thereby forming a reduced pressure sealed space. do.

(Third Embodiment)

In addition, as a separate means for attaching and fixing the dustproof protector to the mask blank by using a vacuum adsorption method using a pressure-reduced closed space, specifically, the airtightness embedded in the groove of the side wall bottom of the dustproof protector as shown in FIG. 5 is maintained. The fixing plate 17 through the sealing material 11, such as an O-ring and a gasket, and the sealing material 11a, such as an O-ring and a gasket, for maintaining separate airtightness in the opening part formed in the side wall part of an anti-vibration protective device, for example. There is a method of using the dustproof protective equipment provided with the resin bag 18 for heat sealing which can be sealed by heat | fever fixed by heat (heat sealing).

First, the mask blank on which the dustproof protective device is placed is placed in the vacuum hermetic chamber 16 with the end of the heat sealing resin bag 18 (the end opposite to the side pressed by the seal member 11a) open. The inside of the hermetic chamber is decompressed by the vacuum pump 15 connected thereto. Thereafter, a method of using a reduced pressure sealed space formed by heat sealing the end portion (heat seal portion 18a of the drawing) of the resin seal for heat sealing and finally returning the vacuum hermetic chamber 16 to normal pressure may be used.

According to this method, the vacuum packing apparatus which is widely used for vacuum packing, such as foodstuff, can be used for fixing and mounting a dustproof protective equipment. In addition, there is no need to transport or store the mask blank with a stop valve or the like provided in the dustproof protective device. The separation of the dustproof protective device during use of the mask blank (that is, as a means for returning the sealed pressure-reduced space to normal pressure) is very easy because the resin bag for heat sealing described above needs to be torn.

(4th Example)

As a separate means for attaching and fixing the dustproof protector to the mask blank by using a vacuum adsorption method using a vacuum decompression space, specifically, to maintain the airtightness embedded in the groove of the side wall bottom of the dustproof protector, as shown in FIG. It is also possible to form a pressure-sensitive sealed space by a seal member 11 such as an O-ring or a gasket, and a sucker mechanism 19 provided on the top plate.

According to this method, it is possible to easily attach and detach the dustproof protective equipment without requiring equipment such as a vacuum pump and a stop valve. In addition, the arrangement | positioning position of the sucker mechanism 19 may be anywhere as long as it can form the pressure-sensitive sealing space with the O-ring for fixing the dustproof protective equipment.

The sucker mechanism 19 is provided with the up-and-down operation mechanism, the fixing mechanism, and the periphery of the sucker, and the sucker is lowered when the dustproof protective equipment is placed or removed, and the sucker is raised when the dustproof protective equipment is mounted and fixed. It has a mechanism which depressurizes the inside, and if there is a volume (volume change amount by the up-and-down movement of a sucker) required to depressurize the said sealed space and to fix a dustproof protection reliably, anything may be sufficient. In addition, it is preferable to select and use the material which does not affect the performance of a resist film as a structural material of a sucker mechanism, such as a sucker material.

As in the first embodiment described above, the increase (difference) of foreign matters before and after the vibration test process was examined, but the increase number of foreign matters was not changed from the first embodiment. In addition, the pattern defect of the mask created using this mask blank was not examined.

(Fifth Embodiment)

As another means for attaching and fixing the dustproof protective equipment to the mask blank by depressurizing the sealed space, as described as the third means (claim 3) of the present invention, the sucker sheet (for fixing the mask blank and the dustproof protective equipment 5) 20) may be employed. Specifically, as shown in FIG. 7, the sucker sheet 20 which consists of resin etc. is previously adsorb | sucked to the bottom of the side wall part of the dustproof protective part 5, and this is next to the non-effective area | region of a mask blank (outside 142 mm angle of board | substrate center). In the region of?

The sucker pattern (shape of the cavity) of the sucker sheet 20 may be any of a mesh shape, a dimple shape, a honeycomb shape, and the like, but when the dustproof protector is attached to the mask blank by the sucker sheet 20, It is preferable to set it as the suction pattern which the cavity part of a suction sheet does not penetrate inside and outside of the said sealing space so that the space formed by the mask blank may be sealed (to prevent entry of foreign matter from the outside). Furthermore, it is preferable to form in the bottom of the side wall part of a dustproof protective body with high density which can acquire the mounting fixed strength as needed. In addition, even if both surfaces are a sucker sheet, the sucker sheet 20 may be a sucker sheet on one side (the side which contact | connects a mask blank), and the other side (the side by which a sucker sheet is fixed to a dustproof protector) may be comprised by what kind of adhesive agent. .

Similarly to the first embodiment described above, the increase (difference) of foreign matters before and after the vibration test treatment was examined, but the increase number of foreign matters was not changed from the first embodiment. In addition, the pattern defect of the mask created using this mask blank was not examined.

(Sixth Embodiment)

As another means for attaching and fixing the dustproof protective device to the mask blank substrate, as described as the fourth means (claim 4) of the present invention, the thermoplastic adhesive has adhesiveness at room temperature, and the adhesiveness is reduced or lost when heated. 21 may be used. Specifically, as shown in FIG. 8, the adhesive 21 is applied to the bottom of the side wall of the dustproof protective part 5, and the dustproof protective part 5 is fixed to the mask blank 101 by the adhesive 21. Let's do it.

As an example, the example which used "thermal peeling sheet river alpha" by Nitto Denko Corporation as an adhesive seat is shown below.

At room temperature, the above-mentioned double-sided adhesive tape obtained by applying a thermoplastic adhesive that has adhesiveness and then deteriorates when heated is applied to one side of the base material (polyester). It is made to adhere to the bottom, and then the thermoplastic adhesive side whose adhesiveness decreases when it heats is adhere | attached on the ineffective area | region (region outside the 142 mm center of board | substrate) of a mask blank.

In the mask manufacturing process, prior to using the mask blank, the mask blank with the dustproof protective device is treated at a predetermined heating temperature by using a hot plate type heat treatment apparatus which is widely used in the mask manufacturing process. (For example 7.5 minutes at 150 ° C.). By the function of this adhesive (adhesion falls by heating), the dustproof protective equipment attached to and fixed to the mask blank is separable.

In the embodiment, although a commercially available double-sided adhesive tape was applied on one side of the base material, which had adhesiveness at a specific room temperature and the adhesiveness decreased when heated, in the case of a mask blank with a resist, It is preferable to select the adhesive which does not affect performance, and the base material of the double-sided tape using the adhesive.

As in the first embodiment described above, the increase (difference) of foreign matters before and after the vibration test process was examined, but the increase number of foreign matters was not changed from the first embodiment. In addition, the pattern defect of the mask created using this mask blank was not examined.

(Seventh embodiment)

As another means for attaching and fixing the above-mentioned dustproof protective equipment to the mask blank substrate, the means as described as the fifth means (claim 5) of the present invention is preferable. That is, when using the thermoplastic adhesive 21 which has adhesiveness at normal temperature and whose adhesiveness falls when it heats, as another structure, the temperature at which the thermoplastic adhesive to be used falls or loses the adhesiveness is more than normal temperature. It is more preferable to use the thermoplastic adhesive 22 which is higher in temperature and lower than any lower temperature of the baking treatment after resist coating or the baking treatment after exposure.

In the case where the adhesive 22 is used, the working mechanism is exactly the same as that shown in Fig. 8, but the heat treatment temperature for degrading the adhesiveness and separating the dustproof protective device 5 is a bake treatment or exposure after applying the resist. The resist film of the heat treatment for separation of the dustproof protector 5, which is lower than the temperature of any of the subsequent bake treatments, particularly when the dustproof protector 5 is attached to and fixed to the mask blank 102 with a resist. Can be minimized (for example, sensitivity change, pattern shape change, film thickness decrease, etc.).

As an example, the example which used "The heat peeling sheet river alpha (thing of the heating temperature of 90 degreeC at the time of peeling)" made from Nitto Denko Corporation as an adhesive sheet is shown below. The double-sided adhesive tape which apply | coated to one side of a base material (polyester) the thermoplastic adhesive which has adhesiveness at the said normal temperature, and adhesiveness falls when heated, and the adhesive side for adhesion of the other base sheet is a side wall of a dustproof protective film The mask blank (resist is a positive chemically amplified resist for electron beam exposure drawing FEP171 (made by Fujifilm Arch)) which a resist adhered to the thermoplastic adhesive side which adheres as a negative bottom, and, when it heats, and the adhesiveness falls after heating. To an ineffective area of the substrate.

In the mask fabrication process, prior to using the mask blank, a hot plate type heat treatment apparatus widely used in the mask fabrication process is used, and the mask blank with the dust protection device is treated at a predetermined heating temperature. (In this example, 7.5 minutes at 90 ° C). By the function of this adhesive (adhesion falls by heating), the dustproof protective equipment attached to and fixed to the mask blank is separable.

The above-mentioned resist FEP171 exhibits maximum performance when both the beta treatment temperature after application and the post-exposure bake treatment temperature are treated at 130 to 150 ° C. Moreover, even if additional heat processing is performed, it is confirmed that if the heating temperature is below the said temperature range, the performance will not be influenced at all.

In the above example, although the commercially available double-sided adhesive tape which applied the thermoplastic adhesive which has adhesiveness at specific room temperature, and whose adhesiveness falls when it heats was applied to one side of the base material was used, the adhesive which does not affect the performance of a resist film, and its It is preferable to select the base material of the double-sided tape using an adhesive agent.

As in the first embodiment described above, the increase (difference) of foreign matters before and after the vibration test process was examined, but the increase number of foreign matters was not changed from the first embodiment. In addition, the pattern defect of the mask created using this mask blank was not examined.

(Eighth Embodiment)

In addition, as a specific example described as the fourth means (claim 4) of the present invention as another form of the dustproof protective device forming the cover shape, as shown in FIG. 9, one side of the frame 23 made of metal such as aluminum A pellicle with a transparent film 22 such as nitrocellulose can be used.

According to this solution, it is possible to visually observe the inside of the airtight space (that is, the mask blank surface) formed by the dustproof protective equipment and the mask blank through the transparent film, and depending on the inspection apparatus, the dustproof protective equipment is mounted ( Through a transparent film such as nitrocellulose), the number of foreign matters on the surface of the mask blank can be counted by a laser surface foreign matter inspection device. This enables inspection of the mask blank surface state after the antivibration protective equipment is attached or before separation.

In addition, although the pellicle is generally mounted on the mask blank through an adhesive, in this solution means, in place of the pellicle mounting adhesive, any of the second and third means is used as a means for attaching the dust protection device to the mask blank. Just do it.

As in the first embodiment described above, the increase (difference) of foreign matters before and after the vibration test process was examined, but the increase number of foreign matters was not changed from the first embodiment. In addition, the pattern defect of the mask created using this mask blank was not examined.

In the above embodiment, the dustproof protective equipment is mounted and fixed after selectively removing the unnecessary resist film at the substrate edge, but the unnecessary resist film at the substrate edge may not be removed. However, it is preferable to remove the unnecessary resist film at the edge of the substrate before attaching and fixing the dustproof protective equipment. Although the surface of the resist film (mask blank) is protected from the direct attachment of dust by the installation of the dust protection device, the occurrence of dust itself can be suppressed by removing unnecessary resist film from the substrate edge or the contact with the dust protection device in advance. For example, when attaching or detaching the dustproof protective device, contamination (increasing foreign matter) on the surface of the mask blank by these dusts can be suppressed. This is not limited to the case where the anti-vibration protective equipment is attached to the mask blank in which only the resist film is formed, and also in the case of laminating an antireflection film, a conductive film, an environmental protection film and the like.

In the above embodiment, the dustproof protective equipment was attached after the formation of the resist film. However, when the mask blank is stored, transported or transported without coating the resist film, the dustproof protective equipment is formed after the formation of the uppermost layer such as a light shielding film or an absorbing film. Just install it.

In the above embodiment, in order to verify the effect of the dustproof protective equipment, after applying the resist, the number of foreign matters on the surface of the mask blank (resist film) is subsequently measured by a laser scanning foreign matter inspection apparatus, and then the dustproof protective equipment is attached. However, you may attach a dustproof protective device immediately after application | coating of a resist. Thereby, direct adhesion of dust to the mask blank (namely, resist film) surface in the foreign material inspection process after resist coating can be prevented.

In addition, in the above embodiment, after the vibration test treatment assuming transport, the number of foreign matters on the surface of the mask blank (resist film) was counted by the laser scanning foreign matter inspection device prior to the exposure treatment after separation of the dustproof protective equipment. Is not necessary.

As mentioned above, in the mask blank produced by the technique which is widely used conventionally, the method of selectively removing the unnecessary resist film of the board | substrate edge part after application | coating of a resist, the resist film by grazing of the mask blank by vibration and a storage container is used. Since there was no peeling and peeling off, the increase of the foreign material before and after the vibration test treatment was clearly suppressed compared with the mask blank which did not remove the unnecessary resist film of the board | substrate edge part. However, even if the unnecessary resist film at the edge of the substrate is removed, the increase in foreign matter before and after the vibration test is not zero.

This is based on the vibration test process (acceleration evaluation assuming transfer and transport), and the contact area (for example, the contact area between the center box and the inside of the outer box) between the mask blank, the storage container, and the constituent members of the storage container. It is thought that dust generated by grazing and contaminated the main surface of the substrate.

These dusts are considered to be caused by grazing between the constituent members of the storage container, or various films formed on the mask blank prior to the formation of the resist film, which are likely to be peeled off or dropped off, and these are attached to the mask blank surface (on the resist film). I can think of it. It is evident that these contaminating foreign matters may cause a defect of a mask (including a reticle), which is a product made of a mask blank as a material, or a decrease in manufacturing yield of the mask.

Therefore, as shown in the above embodiment, both the mask blank formed by attaching the antivibration protective device of the present invention, and the mask blank when the mask blank is taken out to the storage container by the mask blank manufacturing method and the mask manufacturing method of the present invention. Dust caused by grazing and dust caused by grazing between the mask blank caused by vibration or shock when storing, moving or transporting the mask blank in a storage container and each component of the storage container or storage container, and the mask caused by these Foreign matter contamination (increase of foreign matter) on the surface of the blank (i.e., resist film (or mask blank top layer)) is greatly reduced.

By supplying the mask blank to the transfer plate manufacturing process while maintaining the surface defect (foreign material) quality immediately after resist application by the mask blank, the method of manufacturing the mask blank, and the method of manufacturing the transfer plate (mask or stamper) of the present invention. And foreign matter contamination of the surface of the mask blank (i.e., resist film) due to vibration or shock caused by putting the mask blank into or out of the storage container and by placing the mask blank into the storage container, and storing, moving or transporting it. The increase of foreign matters) is suppressed, and the increase in the transfer plate (mask or stamper) defect and the decrease in the yield of the transfer plate (mask or stamper) production are suppressed.

Patent Document 5: Japanese Unexamined Patent Publication No. 2001-259502

As described in detail above, according to the present invention, the foreign matter is transferred to the mask pattern or pattern for pattern transfer on the mask blank main surface during the manufacturing process of the mask blank or transfer plate (mask or stamper) or the storage and transport of the mask blank. It is possible to effectively prevent the possibility of causing a problem by attaching directly to the effective area where the unevenness of use is formed.

[Brief Description of Drawings]

1 is an explanatory view (a to e) of a method of manufacturing a mask blank and a method of manufacturing a mask according to an embodiment of the present invention.

2 is an explanatory diagram (f to j) of a method of manufacturing a mask blank and a method of manufacturing a mask according to an embodiment of the present invention.

3 is a cross-sectional view schematically illustrating a first embodiment of a mask blank according to the present invention.

4 is a cross-sectional view schematically illustrating a second embodiment of the mask blank according to the present invention.

5 is a cross-sectional view schematically illustrating a third embodiment of the mask blank according to the present invention.

6 is a cross-sectional view schematically illustrating a fourth embodiment of the mask blank according to the present invention.

7 is a cross-sectional view schematically illustrating a fifth embodiment of the mask blank according to the present invention.

8 is a cross-sectional view schematically illustrating a sixth embodiment of the mask blank according to the present invention.

9 is a cross-sectional view schematically illustrating an eighth embodiment of the mask blank according to the present invention.

[Description of the code]

1 substrate 2 light shielding film

3: antireflection film 4: resist film

4a: resist pattern 5: dustproof protective equipment

11: Sealing material (side wall bottom of dustproof protective device)

11a: sealing material (for fixing the resin bag for heat sealing)

12: connection portion 13: tube

14: normally closed stop valve 15: vacuum pump

16: vacuum hermetic chamber 17: fixing plate of heat sealing bag

18: resin bag for heat sealing 18a: heat seal

19: sucker mechanism

20: Thermoplastic adhesive (adhesive which has adhesiveness at normal temperature and whose adhesiveness falls or loses by heating)

21: Thermoplastic adhesive (The same as above, the heat treatment temperature at which the adhesiveness is lowered is higher than room temperature and lower than the lower temperature of the resist heating)

22: transparent film 23: aluminum frame

24: adhesive

Claims (7)

A mask blank, which is a material of a pattern transfer mask or stamper, having a mask function thin film optically acting on transfer exposure light and / or a thin film used in a mask manufacturing process, formed on a substrate surface, The mask blank is not in contact with an effective region in which a mask pattern for pattern transfer or an unevenness for pattern transfer is formed on a mask blank main surface on the side where the mask function thin film and / or a thin film used in a mask manufacturing process is formed. And a mask-shaped dustproof protector which is detachably fixed to contact the invalid area to form a closed space. The method of claim 1, The dust protection device, the mask blank surface, A mask blank, which is fixed by using any one of a vacuum adhesive, a suction sheet, or a thermoplastic adhesive that has adhesiveness at room temperature and which loses or loses adhesiveness when heated. The method of claim 2, The said thermoplastic adhesive is the temperature higher than normal temperature, it is lower than the heat processing temperature after formation of a resist film, and the mask blank characterized by the said dust-proof protection tool peeling off on the mask blank surface. The method of claim 1, The dust protection device is a mask blank, characterized in that the surface opposite to the mask blank surface is transparent to visible light or inspection light. The method according to any one of claims 1 to 4, A mask blank, wherein the resist film on the surface of the substrate to which the dustproof protective equipment contacts is removed. A mask blank, which is a material of a pattern transfer mask or stamper, having a mask function thin film optically acting on transfer exposure light and / or a thin film used in a mask manufacturing process, formed on a surface of a substrate, A thin film forming step of forming a mask function thin film optically acting on the transfer exposure light and / or a thin film used for a mask manufacturing process on the substrate surface; On the mask blank main surface of the side on which the mask function thin film and / or the thin film used for the mask manufacturing process are formed, the effective area in which the mask pattern for pattern transfer or the unevenness for pattern transfer are formed is not contacted, and is ineffective. A mask blank manufacturing method, comprising: a dustproof fitting mounting step of attaching a cover-shaped dustproof protector in contact with and forming a closed space. A manufacturing method of a transfer plate having a transfer pattern forming step of forming a mask pattern for pattern transfer or irregularities for pattern transfer on a substrate surface using a mask blank that is a material of a pattern transfer mask, Using the mask blank of any one of Claims 1-5, after isolate | separating the said dustproof protective device of this mask blank, the said mask pattern formation process is performed, The manufacturing method of the transfer plate characterized by the above-mentioned.

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