KR20080091720A - Method for manufacturing mask blanks and method for manufacturing photomask - Google Patents

Abstract

A method for manufacturing a mask blank is provided to obtain a drying step capable of drying a coated resist liquid perfectly so as to prevent the occurrence of stains after drying. A method for manufacturing a mask blank having a resist film includes: a resist coating step of while a resist liquid is discharged from a coating nozzle(22) having a supply port of the resist liquid extending in one direction, moving the coating nozzle and a surface of a substrate(10) relatively in a direction intersecting with the one direction to coat the surface of the substrate with the resist liquid; and a drying step of feeding pure gas from a direction parallel to the resist-coated surface(21a) to dry the coated resist.

Description

The manufacturing method of the mask blank and the manufacturing method of a photo mask {METHOD FOR MANUFACTURING MASK BLANKS AND METHOD FOR MANUFACTURING PHOTOMASK}

This invention relates to the manufacturing method of a mask blank, and the manufacturing method of a photo mask.

In the mask blank (mask blank for FPD) for manufacturing a flat panel display (FPD) device, a resist film is formed on thin films, such as a light shielding film and a semi-transmissive film. This resist film is used as an etching mask in the etching of the said thin film. However, in the mask blank for FPD, since the surface area of the said thin film surface which will form a resist film is large, compared with the mask blank for LSI etc., application | coating spot of a resist film and deterioration of in-plane film thickness uniformity are easy to occur, for example.

Moreover, in the photomask for FPD etc., in recent years, since the pattern formed becomes high precision, the technique which can form the resist film of uniform thickness over the whole surface of a large board | substrate was desired.

In view of such a situation, the use of the coating apparatus collectively called "CAP coater", for example, in the manufacture field of the mask blank and photo mask for FPD is considered. In this "CAP coater", the application | coating nozzle which has a capillary clearance gap is submerged in the liquid tank in which the liquid resist agent was stored. On the other hand, the board | substrate is hold | maintained by an adsorption plate in the attitude | position facing downward, Next, an application | coating nozzle is raised from the inside of a resist agent, and the upper end part of this application | coating nozzle is made to be close to the application surface of a board | substrate. Then, the liquid resist agent stored in the liquid tank rises by the capillary phenomenon in the application nozzle, and the resist agent comes into contact with the surface to be coated of the substrate through the upper end of the application nozzle. Thus, in the state which contacted the to-be-coated surface with a resist agent, a liquid tank and an application | coating nozzle are lowered to the position (position of coating gap G) of a predetermined "coating height." In this state, the coating nozzle and the surface to be coated are relatively moved over the entire surface of the surface to be coated, whereby a coating film made of a resist is formed over the entire surface of the surface to be coated.

By the way, even when using the above-mentioned CAP coater, in order to meet the request | requirement of a high precision pattern, etc. further, it is necessary to pursue the uniformity of a film thickness further. Therefore, preventing occurrence of in-plane dry spots during drying after application is also an important factor in terms of improving the uniformity of the film thickness.

Accordingly, the present inventors dry the substrate while moving the substrate at a constant speed while keeping the coated surface of the substrate downward in order to prevent the film thickness stain of the resist film caused by the dry stain caused by the airflow of the downflow in the clean room. A resist coating method (Patent Document 1: Japanese Patent Laid-Open No. 2004-311884) or a resist coating method for suppressing the downflow from returning to the surface to be coated by supplying a clean gas from below the surface to be coated to the resist film (Patent Document 1) 2: Japanese Patent No. 3658355) was developed and filed first.

By the way, when the above-mentioned method was applied to the specific coating apparatus demonstrated below, it turned out that dry unevenness generate | occur | produces.

In detail, the coating device shown in FIG. 7 is an apparatus of the type which adsorbs and detaches the board | substrate 10 with respect to the adsorption plate 3 on the apparatus front surface (loader) side, and has the following adsorption and removal mechanisms. That is, the adsorption and desorption mechanism adsorbs the substrate 10 to the adsorption plate 3 from the apparatus front side (position C in the drawing), while moving the adsorption plate 3 and the substrate 10 in the right direction in the drawing, The coating nozzle 22 is applied to the surface to be coated of the substrate 10 to form a resist coating film 21a (details will be described later). After the application is completed, the movement of the adsorption plate 3 and the substrate 10 is stopped at a position where the adsorption plate 3 and the substrate 10 are slightly moved (called an application end position) in the drawing in the right direction. Next, the adsorption plate 3 and the board | substrate 10 are moved to the left direction in the figure, and the board | substrate 10 is separated from the adsorption plate 3 in the apparatus front side (position C in a figure). Hereinafter, the right end part in the figure of the board | substrate 10 is called application | coating start side, and the left end part in the figure is called application | coating end side.

In the coating device shown in FIG. 7, the board | substrate 10 which application | coating completed is stopped once in the position (application end position) of A in a figure. Thereafter, the substrate 10 moves to the loader side, but in the clean air unit 31 provided below the position B in the figure, the substrate 10 moves to the loader side while the resist surface is dried.

The problem with this drying method is that the application direction and the drying direction are in the reverse direction, and that uniform drying time is not sufficiently taken. In fact, the application end side first receives the wind from the lower air unit 31 at the position B in the figure, and the application start side last.

For this reason, if the feed rate (coating return speed) of the adsorption plate 3 moving from A to B to C after application is too high, drying at the position B is not sufficient, and the longitudinal direction as shown in FIG. Ajiru spots (swain-shaped spots) are generated. On the contrary, when the application rewinding speed is lowered, the azidden stain in the longitudinal direction is reduced, but since the application start area (the application start side) is naturally dried before reaching the position B in the drawing, the randomness as shown in FIG. One cold spot is generated around the application start area. Numerous tests were carried out by varying the coating return speed, the number, the height, and the air volume of the air unit. However, it was not possible to simultaneously suppress the vertical azimuth stains and the random azidrome stains to an acceptable level.

In addition, drying is performed also in the air unit 32 provided under the C position in the figure. However, the drying here is for promoting the drying of the resist at the level leading to the next step by placing the substrate on the loader, and drying after reaching the `` sufficient dry state '' described later. Explaining not to give.

This invention is made | formed in view of the said subject, and an object of this invention is to provide the manufacturing method of the mask blank which has a process which can dry the apply | coated resist agent so that the above-mentioned dry spot may not generate | occur | produce.

This invention has the following structures.

[Configuration 1]

While discharging the resist liquid from the coating nozzle having the resist liquid supply port extending in one direction, the surface to be coated of the coating nozzle and the substrate is relatively moved in the direction crossing the one direction so that the resist is applied to the surface to be coated. As a manufacturing method of the mask blank which has a resist film which has a resist coating process apply | coated,

Drying of the apply | coated resist agent has a process of supplying and drying a clean gas from the direction parallel to the coating film surface of a resist agent, The manufacturing method of the mask blank characterized by the above-mentioned.

[Configuration 2]

Drying of the applied resist is

A rectifying plate is provided opposite to the coating film surface made of resist,

The manufacturing method of the mask blank of the structure 1 characterized by having the process of supplying a clean gas between the coating film surface of the said resist agent, and the said rectification plate, and drying it.

[Configuration 3]

A clean gas is supplied from the coating start side toward the coating end side with respect to the coating film surface of the said resist agent, The manufacturing method of the mask blank of the structure 1 or 2 characterized by the above-mentioned.

[Configuration 4]

The liquid resist agent stored in the liquid tank is raised by a capillary phenomenon in the coating nozzle, the surface to be coated is brought closer to the upper end of the coating nozzle downward, and the resist agent raised by the coating nozzle is applied to the coating nozzle. And the liquid bath and the application nozzle are lowered to a position of a predetermined application height in a state where the resist is in contact with the application surface of the substrate, and in this state, the application nozzle and the application surface are relatively It moves to and has a resist agent application process which apply | coats the said resist agent to the to-be-coated surface, The manufacturing method of the mask blank in any one of the structures 1-3 characterized by the above-mentioned.

[Configuration 5]

The photomask is manufactured using the mask blank obtained by the manufacturing method of the mask blank in any one of the structures 1-4, The manufacturing method of the photomask characterized by the above-mentioned.

According to this invention, the manufacturing method of the mask blank which has the process which can dry the apply | coated resist agent so that dry stain as mentioned above does not generate | occur | produce can be provided.

Hereinafter, the present invention will be described in more detail.

The method for producing a mask blank of the present invention relatively moves the coated surface of the coating nozzle and the substrate in a direction crossing the one direction while discharging the resist liquid from the coating nozzle having a resist liquid supply port extending in one direction. As a method for producing a mask blank having a resist film having a resist agent coating step of applying the resist agent to the surface to be coated,

Drying of the apply | coated resist agent has a process of supplying a clean gas from the direction parallel to the coating film surface of a resist agent, and drying it (constitution 1).

According to the invention according to the above structure 1, drying of the applied resist is performed from a direction parallel to the surface of the coating film of the resist (that is, the surface of the coating film formed by the applied resist, ie, the surface of the resist film, hereinafter). By having a process of supplying a clean gas and drying, compared with the case of supplying a clean gas from the direction perpendicular | vertical with respect to the coating film surface made of resist, etc., the flow of dry air flow is one direction, and dry stain is prevented. .

In addition, in the invention according to the first aspect, the solvent vapor which volatilizes from the coating film surface of the resist and remains near the coating film surface by flowing a clean gas along the surface of the coating film made of resist and parallel to the coating film surface. It is possible to force away from the coating film surface.

In the present invention, the forced drying by the supply of the clean gas is dried to a state (hereinafter referred to as a sufficient dry state) that can prevent the natural drying occurs after the forced drying due to the lack of forced drying and the resulting dry stains. It is preferable.

In the present invention, as will be described later, the forced drying by the supply of the clean gas is a step of preventing the drying unevenness caused by natural drying before the forced drying and drying to a sufficient dry state. Do.

In this invention, it is preferable that the drying of the apply | coated resist agent has a process which provides a rectifying plate opposite to the coating film surface of a resist agent, supplies a clean gas between the said coating film surface, and the said rectification plate, and makes it dry. (Configuration 2).

Here, unless a rectifying plate is provided opposite to the coating film surface of a resist agent, the clean gas supplied from the direction parallel to the coating film surface of a resist will diverge in the direction away from the said coating film surface.

According to the invention according to the above structure 2, since the rectifying plate is provided opposite to the coating film surface made of resist, the direction in which the clean gas supplied from the direction parallel to the coating film surface made of resist moves away from the coating film surface. It is not emitted by. For this reason, uniform blowing to the coating film surface of a resist becomes possible.

Moreover, according to the invention according to the above-described structure 2, the drying efficiency is higher than in the case of supplying a clean gas from a direction perpendicular to the surface of the coating film made of a resist or the like. Therefore, the time required to reach sufficient dry state can be shortened. On the other hand, as with other drying methods, if the drying efficiency is low and, therefore, the time required to reach a sufficient drying state is long, it may be due to natural drying during the time of reaching a sufficient dry state by forced drying by blowing. Dry stains may occur. In addition, when the time required to reach a sufficient dry state is long, it is disadvantageous in terms of throughput. If the priority is given to the throughput and the forced drying time due to blowing is shortened, natural drying occurs after the forced drying due to the lack of forced drying, and dry staining occurs.

In this invention, it is preferable that the space | interval between the coating film surface of a resist agent, and the rectifying plate surface shall be 1-2 cm from a viewpoint of sufficient exhibition of the above-mentioned effect | action. Moreover, it is more preferable to send a clean gas uniformly by the air nozzle etc. of a shape suitable for this space | interval.

In the present invention, the flow rate of the clean gas supplied and passed between the coating film surface and the rectifying plate is preferably 0.2 to 1 m / sec from the viewpoint of sufficient exertion of the above-described action.

If the flow velocity (air strength) of the clean gas is too high, ribbed dry spots as shown in FIG. 5 occur.

If the flow rate (air strength) of the clean gas is too low, as shown in Fig. 6, it is naturally dried before the application completion area (the application end side) reaches a sufficient dry state, and random azidrome stains (arranged) Stains).

In this invention, it is preferable to arrange | position the said rectification plate in parallel with respect to the coating film surface (hence the surface of a board | substrate or an adsorption plate) made from resist. That is, it is preferable that the space | interval between the coating film surface of a resist agent, and the rectifying plate surface is made into a fixed space | interval at any place in the surface of the coating film surface of a resist agent.

In the present invention, the area of the rectifying plate is preferably larger than the area of the surface of the coating film made of resist, more preferably the same as or larger than the area of the substrate (that is, the size covering the substrate). More preferably, it is the same as or larger than the area (that is, the size covering the suction plate).

In this invention, it is preferable to supply a clean gas from the application | coating start side toward the application | coating end side (structure 3).

According to the invention according to the above-described structure 3, since the clean gas is supplied from the application start side to the application end side, drying can be performed from the application start area side (application start side). Drying stain resulting from natural drying does not occur before forced drying by. This is because the area closer to the side for supplying the clean gas (that is, the side on which the wind blows) is dried faster than the other area (that is, the side on which the wind blows).

In this invention, it is preferable to supply a clean gas uniformly toward the side of the application | coating end side from the side of the application | coating start side in the coating film surface of resist.

In this invention, after completion | finish of application | coating, the drying process which concerns on the said invention can be performed in the state which stopped the movement of a board | substrate at the position (coating end position) of the near side, and stopped this movement. One).

Moreover, in this invention, the drying process which concerns on the said invention can be implemented, moving and applying a board | substrate at a fixed speed (method 2). For example, the drying process according to the present invention can be carried out by supplying a clean gas before or immediately after the start of coating. In addition, it is possible to carry out the drying process according to the present invention by supplying a clean gas from the step of applying a predetermined area from the start of coating. In addition, a clean gas may be supplied immediately after the completion of the coating to perform the drying step according to the present invention.

In addition, the application start side has a longer elapsed time after application than the application end side, and there is a concern that dry spots due to natural drying may occur before forced drying by supply of clean gas, but according to the method 1 or 2 above, Since the time until the forced drying start by supply of clean gas can be shortened, such a concern can be prevented.

The present invention relatively displaces the coating surface of the coating nozzle and the substrate in the direction crossing the one direction while discharging the resist liquid from the coating nozzle having the resist liquid supply port extending in one direction, It is applicable to the case of using the application apparatus called a slit coater which apply | coats the said resist agent. The positional relationship between the application nozzle and the substrate in the slit coater is not particularly limited, and the application nozzle is provided above the substrate held horizontally with respect to the bottom surface, or both the application nozzle and the substrate are perpendicular to the bottom surface. And the like are maintained.

This invention can be applied suitably when using the coating device collectively called "CAP coater." (Configuration 4).

The manufacturing method of the photomask of this invention is characterized by manufacturing a photomask using the mask blank obtained by the manufacturing method of the mask blank which concerns on the said invention (Configuration 5).

The mask blank of this invention contains the mask blank provided with the thin film for forming the mask pattern formed into a film on the board | substrate, and the resist film formed into a film above this thin film.

In the present invention, the mask blank also includes a photo mask blank, a phase shift mask blank, a reflective mask blank, and an imprint transfer plate substrate. The mask blank includes a mask blank having a resist film. The phase shift mask blank includes a case having a halftone film and a light shielding film. In this case, the thin film for forming the mask pattern refers to a halftone film or a light shielding film. In the case of the reflective mask blank, a tantalum-based material or a chromium-based material as a transfer pattern is formed on the multilayer reflective film or on the buffer layer formed on the multilayer reflective film, and in the case of an imprint transfer plate, And a constitution in which a thin film for forming a transfer pattern, such as a chromium-based material, is formed on a substrate that is a transfer plate. The mask includes a photo mask, a phase shift mask, a reflective mask, and an imprint transfer plate. The mask includes a reticle.

In the present invention, as a thin film for forming a mask pattern, a light shielding film for blocking exposure light and the like, a semi-transmissive film for adjusting and controlling the transmission amount of exposure light and the like, and a reflectance control film for adjusting and controlling the reflectance of exposure light and the like (reflection A protective film), a phase shift film for changing a phase with respect to exposure light, a halftone film having a light shielding function and a phase shift function, and the like.

In the mask blank of this invention, a metal film is mentioned as a thin film for forming the said mask pattern. Examples of the metal film include chromium, tantalum, molybdenum, titanium, hafnium and tungsten, an alloy containing these elements, or a film made of the element or the material containing the alloy.

Moreover, in the mask blank of this invention, the silicon containing film containing silicon is mentioned as a thin film for forming the said mask pattern. The silicon-containing film further contains at least one of oxygen, nitrogen, and carbon in a silicon film, a metal silicide film containing silicon and metals of chromium, tantalum, molybdenum, titanium, hafnium, and tungsten, a silicon film or a metal silicide film. I can do it.

In the present invention, examples of mask blanks and masks for FPD include mask blanks and masks for manufacturing FPD devices such as LCD (liquid crystal display), plasma display, organic EL (electroluminescence) display, and the like.

The mask for LCD includes all masks necessary for the manufacture of the LCD, and for example, to form a TFT (thin film transistor), especially a TFT channel portion or a contact hole portion, a low temperature polysilicon TFT, a color filter, a reflector (black matrix), and the like. For the mask is included. Other masks for manufacturing display devices include all masks necessary for manufacturing organic EL (electroluminescence) displays, plasma displays and the like.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a typical side view for demonstrating one aspect of the application | coating apparatus collectively called "CAP coater" concerning embodiment of this invention, and the drying process in this invention, and FIG. 2 is a top view of the principal part of FIG.

1 and 2 are apparatuses of the type which adsorb and detach the substrate 10 to the adsorption plate 3 from the apparatus front face (loader) side, and have the following adsorption and desorption mechanisms. That is, the adsorption and desorption mechanism adsorbs the substrate 10 to the adsorption plate 3 from the apparatus front side (position C in the drawing), while moving the adsorption plate 3 and the substrate 10 in the right direction in the drawing, The coating nozzle 22 is applied to the surface to be coated of the substrate 10 to form a resist coating film 21a (details will be described later). After the application is completed, the movement of the adsorption plate 3 and the substrate 10 is stopped at a position where the adsorption plate 3 and the substrate 10 are slightly moved (called an application end position) in the drawing in the right direction. Next, the adsorption plate 3 and the board | substrate 10 are moved to the left direction in the figure, and the board | substrate 10 is separated from the adsorption plate 3 in the apparatus front side (position C in a figure). Hereinafter, the right end part in the figure of the board | substrate 10 is called application | coating start side, and the left end part in the figure is called application | coating end side.

In the coating apparatus shown in FIG. 1 and FIG. 2, the rectifying plate 50 is provided facing the surface of the coating film made of resist (that is, the surface of coating film 21a made of resist). The rectifying plate 50 is provided horizontally at a predetermined interval with respect to the coating film surface made of resist. In addition, as shown in FIG. 2, the rectifying plate 50 is sized to cover the substrate 10 and the adsorption plate 3. The rectifying plate 50 is provided adjacent to (approximately) the application nozzle 22.

In the coating device shown in FIG. 1, the supply means of the clean gas to the apparatus back side (the moving direction side of the board | substrate at the time of application) on the opposite side to an apparatus front side so that clean gas may be supplied from the application start side to the application | coating end side. The in-air unit 60 is installed.

The air unit 60 supplies the clean gas from the direction parallel to the surface of the coating film made of resist (that is, the surface of the coating film 21a made of resist) so as to blow out in parallel with the surface of the coating film 21a. ), And a clean gas flows between the resist coating film surface and the rectifying plate along the resist coating film surface, and in parallel.

As shown in FIG. 2, the air unit 60 is provided in multiple numbers along the side of the coating start side in the coating film surface of resist, and by this, the side of the coating start side in the coating film surface of resist is provided. Clean gas is uniformly supplied from the side toward the side of the application | coating end side.

The air unit 60 is equipped with the fan which generate | occur | produces airflow, for example, and the air filter arrange | positioned in front of this fan, and supplies clean gas through an air filter. Here, it is preferable to use a HEPA filter (High Efficiency Particulate Air filter) as an air filter.

FIG. 3 is a cross-sectional view for explaining a state in which a coating agent 22 is applied to a surface to be coated on the substrate 10 by the coating nozzle 22. FIG. 4 is for explaining details of operations of the coating nozzle 22 and the like. It is a section for.

In the "CAP coater" apparatus, first, position alignment with the application start point of the resist agent in the board | substrate 10 and the upper end part of the application nozzle 22 of the application unit 2 is performed (not shown). The application start point of the resist agent in the substrate 10 is one side edge of the substrate 10.

In addition, this "CAP coater" apparatus includes a horizontal drive mechanism for horizontally moving the suction plate 3, a vertical drive mechanism (not shown) for vertically moving the liquid tank and the application nozzle, and a horizontal drive mechanism as described later. In addition to controlling, the control unit (not shown) controls the vertical drive mechanism to adjust the height positions of the liquid bath and the application nozzle.

In the above state, as shown in FIG. 4, the control unit includes a liquid tank 20 in which a resist agent 21 is stored up to a predetermined liquid level and a coating nozzle in which the resist agent 21 completely sinks. All of 22 is raised and made to approach the to-be-coated surface 10a of the board | substrate 10 from below.

In addition, the coating nozzle 22 is supported by the support rod 28 and is accommodated in the liquid tank 20. This application | coating nozzle 22 and the liquid tank 20 are comprised with the length corresponding to the length of one side of the board | substrate 10 in the horizontal direction (direction orthogonal to the paper surface in FIG. 3). The coating nozzle 22 has a slit-like capillary clearance 23 along the longitudinal direction. The coating nozzle 22 is configured to have a cross-sectional shape with a sharp tip like a beak with a narrow width at the upper end side with the capillary gap 23 interposed therebetween. The upper end of the capillary gap 23 is open at the upper end of the application nozzle 22 in a slit shape over the entire length of the application nozzle 22. Moreover, this capillary clearance 23 is open also toward the downward side of the coating nozzle 22 (refer FIG. 3, 4).

Next, the control unit stops the rising of the liquid tank 20, and projects the upper end side of the coating nozzle 22 from the liquid surface of the resist agent 21 in the liquid tank 20 upward as shown in FIG. 3. At this time, since the coating nozzle 22 protrudes to the upper side of the liquid level of the resist agent 21 from the state completely submerged in the resist agent 21 (see FIG. 4), the resist agent is formed in the capillary gap 23. 21 is in a filled state (see FIG. 3). In addition, the support rod 28 penetrates the hole 20b formed in the bottom part of the liquid tank 20 in the state which can move up and down. And in order to eliminate the leak of the resist agent 21 from the slight gap between the hole 20b and the support rod 28, it supports between the circumference | surroundings of the application | coating nozzle 22 and the hole 20b of the liquid tank 20. The flexible crimp hose 29 is provided so that a part of the rod 28 may be contained.

Moreover, the control part raises the application | coating nozzle 22, and makes the resist agent 21 of the upper end part of the application | coating nozzle 22 contact with the to-be-coated surface 10a of the board | substrate 10 (refer FIG. 3).

At this liquid contact, the liquid contact is started in a relatively small state between the distal end of the application nozzle 22 and the surface to be coated 10a, and then the distal end of the application nozzle 22 and the surface to be coated 10a It is preferable to widen the spacing in a relatively large state to complete the liquid contact. Specifically, for example, it is preferable that the liquid contact gap g be kept in a small state in a small state to start the liquid contact, and the liquid contact gap g is widened to complete the liquid contact so that the liquid contact rate immediately prevents foaming from occurring.

Next, the control part controls the liquid tank 20 and the application | coating nozzle 22 in predetermined | prescribed state in the state in which the resist agent 21 contacted the to-be-coated surface 10a of the board | substrate 10 at the upper end part of the application | coating nozzle 22. It is set to the space | interval (coating gap G) of the front-end | tip part of the application | coating nozzle 22 and the to-be-coated surface 10a at the time of application | coating to the position of application | coating height "(refer FIG. 3).

Here, the coating gap G is made as large as possible in the range smaller than the liquid separation space G 'which the resist agent 21 which liquid-contacted once liquid transfers from the to-be-coated surface 10a. That is, the coating gap G is made up of at least 50% or more of the lip solution interval G ', and preferably, 70% to 95% of the lip solution interval G'.

In the above state, the control unit moves the substrate 10 in a direction orthogonal to the slit formed by the capillary gap 23 at the upper end of the coating nozzle 22 (direction indicated by arrow V in FIG. 3), and the coating is performed. The upper end of the nozzle 22 is moved over the whole surface of the to-be-coated surface 10a, and the coating film 21a of the resist agent 21 is formed over the whole surface of this to-be-coated surface 10a.

In addition, the relative movement speed of the board | substrate 10 and the application | coating nozzle 22 is based on the nozzle space preset, the viscosity of the resist agent 21, liquid level, and application | coating gap G, and the coating film 21a. It is controlled by the control unit so that the desired film thickness is achieved.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail based on an Example.

Example 1

Using a coating apparatus having the structure shown in Figs. 1 to 4 described in the above-described embodiment of the invention, by the method described in the embodiment, a resist is applied onto the thin film of the mask blank and dried to form a resist film. The mask blank having was formed.

In that case, the conditions of application | coating set the liquid level, application | coating gap, the moving speed, etc. for forming a 1 micrometer resist film.

In addition, the conditions of drying stop the movement of a board | substrate at the application | coating end position (position of A in drawing) shown in FIG. 1 and FIG. Clean gas was flowed in parallel with the coating film surface made of resist. At this time, the space | interval of the coating film surface of a resist agent and the rectifying plate surface was 1 to 2 cm. In addition, the flow velocity of the clean gas supplied and passed between the coating film surface and the rectifying plate was 0.5 m / sec. The supply time (drying time) of the clean gas was 10 minutes.

As the mask blank, a substrate having a thin film for forming a mask pattern was used on a large glass substrate (synthetic quartz (QZ) 10 mm thick, size 850 mm x 1200 mm).

As a result of inspecting the mask blank having the resist film obtained above, the coated and dried resist film after a certain period of time, the vertical azirconia stain (arranged stain) as shown in FIG. No random azidrome stains (stains of azirconia) were seen.

Moreover, although the photomask was produced using the mask blank which has the resist film obtained above, and FPD was produced using this photomask, it is thought that it originates in said dry spot of a resist film with respect to both a photomask and FPD. No abnormality was seen.

Comparative Example 1

The mask blank which has a resist film was formed using the coating device shown in FIG. In addition, the conditions of application | coating were made similarly to Example 1.

If the conveying speed (coating return speed) of the adsorption plate moving from A to B to C after application is too high, drying at position B is not sufficient, and vertical azirconia stains as shown in FIG. Stains).

On the contrary, when the application rewinding speed is lowered, the vertical azirconia stain is reduced, but since the application start area is naturally dried before reaching the position B in the figure, random azidrome staining (azidine) is shown in FIG. Unevenness of shape) occurred centering on the coating start area.

Numerous tests were carried out by varying the coating return speed, the number, the height, and the air volume of the air unit 31, but it was not possible to simultaneously suppress the vertical azimuth stain and the random azidrome stain to the acceptable level.

Reference Example 1

In the coating device shown in FIG. 7, similarly to the clean air unit 31 provided below the position B in the figure, a clean air unit (not shown) is provided below the position A in the figure, and the application is completed. In the state which stopped the prepared board | substrate at the position (application end position) of A in the figure, clean gas was supplied from the clean air unit installed below toward the coating film surface of the applied resist, and it dried. As a result, dry spots shown in FIG. 8 occurred.

In addition, this invention is not limited only to the above-mentioned embodiment, Of course, various changes can be implemented within the range which does not deviate from the summary of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic side view for demonstrating one aspect of the drying process in this invention.

2 is a plan view of the main part of FIG. 1;

3 is a cross-sectional view showing a state in which an application means is applied in an application device according to an aspect of the present invention.

4 is a cross-sectional view showing a configuration of main parts of the application means in the application device of FIG. 3.

It is a schematic diagram for demonstrating one aspect of the dry stain by drying conditions.

It is a schematic diagram for demonstrating the other aspect of the dry stain by drying conditions.

7 is a schematic side view for explaining one aspect of a conventional drying step.

The schematic diagram for demonstrating one aspect of the dry stain by the conventional drying process.

It is a schematic diagram for demonstrating one aspect of the dry stain by the conventional drying process.

<Explanation of symbols for main parts of the drawings>

2: coating unit

3: adsorption plate

10: substrate

10a: coated surface

20: liquid tank

20b: hole

21: resist

21a: coating film made of resist

22: application nozzle

23: capillary gap

28: support bar

29: crimped hose

50: rectification plate

60: air unit

Claims (5)

While discharging the resist liquid from the coating nozzle having the resist liquid supply port extending in one direction, the surface to be coated of the coating nozzle and the substrate is relatively moved in the direction crossing the one direction so that the resist is applied to the surface to be coated. As a manufacturing method of the mask blank which has a resist film which has a resist coating process apply | coated, Drying of the apply | coated resist agent has a process of supplying and drying a clean gas from the direction parallel to the coating film surface of a resist agent, The manufacturing method of the mask blank characterized by the above-mentioned. The method of claim 1, Drying of the applied resist is A rectifying plate is provided opposite to the coating film surface made of resist, And a step of supplying a clean gas between the coating film surface of the resist and the rectifying plate and drying the mask film. The method of claim 1, A clean gas is supplied from the coating start side toward the coating end side with respect to the coating film surface of the said resist agent, The manufacturing method of the mask blank characterized by the above-mentioned. The method of claim 1, The liquid resist agent stored in the liquid tank is raised by a capillary phenomenon in the coating nozzle, the surface to be coated is brought closer to the upper end of the coating nozzle downward, and the resist agent raised by the coating nozzle is applied to the coating nozzle. And the liquid bath and the application nozzle are lowered to a position of a predetermined application height in a state where the resist is in contact with the application surface of the substrate, and in this state, the application nozzle and the application surface are relatively And a resist agent coating step of applying the resist agent to the surface to be coated, by moving to. The photomask is manufactured using the mask blank obtained by the manufacturing method of the mask blank of any one of Claims 1-4.

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