JP2009142749A - Photomask blank, photomask, their manufacturing methods and coater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photomask blank enabling formation of a uniform resist film through good liquid contact, a photomask, their manufacturing methods and a coater. <P>SOLUTION: The method of manufacturing the photomask blank comprises the steps of causing a resist liquid 21 to rise through the capillarity of the nozzle 22 disposed in a coater, bringing the rising resist liquid 21 into contact with the to-be-coated surface 10a of a substrate 10 arranged downward and moving the nozzle 22 and the substrate 10 relatively to form a resist film on the to-be-coated surface 10a. The resist liquid 21 is brought into contact with the target surface from a single liquid-contact position P1 arranged in the coater or the to-be-coated surface 10a of the substrate 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photomask blank, a photomask, a method for manufacturing the same, and a coating apparatus. For example, the photomask blank is manufactured using a step of applying a resist film to the surface of a substrate, and is obtained using the photomask blank. The present invention relates to a photomask, a manufacturing method thereof, and a coating apparatus.

  Conventionally, as a coating apparatus (coater) for applying a coating solution such as a photoresist to a substrate such as a photomask blank substrate or a silicon wafer, the coating solution is usually dropped at the center of the substrate, and then the substrate is rotated at a high speed. A spin coater that extends a coating solution by the action of centrifugal force to form a coating film on the substrate surface has been used.

  By the way, the above-mentioned spin coater has a problem that a swell called resist fringe occurs at the peripheral edge of the substrate. In particular, in a liquid crystal display device or a photomask for manufacturing a liquid crystal display device, it is necessary to apply a resist to a large substrate (for example, a rectangular substrate having a side of 300 mm or more). As the substrate size increases, development of a technique for applying a uniform resist film to a large substrate has been desired.

  As one measure for solving this problem, a coating device called a CAP coater (capillary coater) is provided as a device using a technique for coating a uniform resist film on a large substrate (see Patent Document 1). . In this CAP coater, a nozzle having a capillary gap is submerged in a liquid tank in which a coating solution is stored, and the nozzle is applied to the vicinity of the coating surface of the substrate held by the suction plate with the coating surface facing downward. The coating film is formed by bringing the coating liquid into contact with the capillary gap and then scanning the nozzle relatively over the surface to be coated.

  Specifically, the nozzle that is completely submerged in the resist in the liquid tank filled with the resist up to a predetermined height is raised below the substrate to be coated. Next, the controller stops the rise of the liquid tank at one end, and causes only the nozzle to protrude from the liquid tank. Here, since the nozzle was completely submerged in the resist, the capillary gap was filled with the resist. That is, the nozzle rises in a state where the resist is filled up to the tip of the capillary gap.

  Next, the control unit stops the rise of only the nozzle and raises the liquid tank again, thereby bringing the resist into contact with the coated surface of the photomask blank. That is, the control unit brings the resist filled in the capillary gap of the nozzle into contact with the surface to be coated. In this way, with the resist in contact with the application surface of the photomask blank, the liquid tank is lowered to the application height position together with the nozzle, and the photomask blank is moved to move the nozzle over the entire application surface. A resist film is formed by scanning over the entire area.

If this apparatus is used, the problem of the conventional spin coater can be solved without generating fringes at the peripheral edge of the substrate.
JP 2004-327963 A

  By the way, in such a conventional CAP coater, a nozzle extended to the length in the width direction orthogonal to the moving direction related to the coating operation is applied to the substrate to which the resist film is applied. The resist is brought into contact with the coated surface by approaching the position. That is, when the resist is in contact with the liquid, it is intended that the resist is in contact with the coated surface of the substrate from the nozzle almost simultaneously in the width direction of the substrate.

  However, when the resist is brought into contact with the coated surface of the substrate by such a method, it is difficult to bring the resist into contact with the entire region in the width direction of the substrate at the same time. In particular, in a substrate for a liquid crystal device and a photomask for manufacturing a liquid crystal device, the size of the substrate is rapidly increasing, and the length of the linear liquid contact portion becomes a size exceeding several hundred mm or 1000 mm. . When the resist solution is brought into contact with such a substrate, the liquid contact state gradually expands in the width direction of the substrate from the liquid contact points after contacting the substrate at a plurality of locations in the width direction of the substrate.

  As described above, when the liquid contact is made at a plurality of locations, there is a problem that bubbles are mixed in the liquid contact portion when the liquid contact areas expanded from two adjacent liquid contact points collide with each other. When air bubbles are mixed into the wetted part and the resist is applied to the entire coated surface of the substrate by moving the substrate and the nozzle relative to each other, a linear mark is generated on the surface of the resist film due to the part where the air bubbles are mixed. As a result, it becomes difficult to form a uniform resist film. Further, the collision between the liquid contact areas locally increases or decreases the amount of the resist solution in the portion, and if the substrate and the nozzle move relative to each other in this state, a linear mark may be generated or the film thickness may be reduced. It has been found by the inventor that non-uniformity occurs.

  This invention is made | formed in view of this point, and it aims at providing the photomask blank which can form a uniform resist film with favorable liquid contact, a photomask, those manufacturing methods, and a coating device. And

  The method for producing a photomask blank of the present invention raises a resist solution by capillary action of a nozzle provided in a coating apparatus, and brings the raised resist solution into contact with a coated surface of a substrate directed downward, A method for manufacturing a photomask blank, comprising: relatively moving the nozzle and the substrate to form a resist film on the surface to be coated, wherein the resist solution is applied to the coating apparatus or the surface to be coated of the substrate It is characterized in that liquid contact is performed from one liquid contact starting point provided on the surface. According to this method, the resist solution comes into contact with the coated surface of the substrate at one liquid contact origin, thereby preventing air bubbles from being mixed into the resist film that occurs when the liquid comes into contact at multiple locations. Can do. Thereby, it is possible to form a resist film free from linear traces and film thickness fluctuations.

  In the photomask blank manufacturing method according to the present invention, it is preferable that the liquid contact origin is a protrusion provided on a surface to be coated of the substrate. In this case, the resist solution first comes into contact with one protrusion provided on the surface to be coated of the substrate, and the liquid contact region expands starting from this liquid contact portion, thereby mixing bubbles in the resist solution. In addition, fluctuations in film thickness can be prevented. Further, by providing a protrusion as a liquid contact starting point on the substrate side, a good resist film can be formed without changing the configuration of the coating apparatus.

  In the method for manufacturing a photomask blank according to the present invention, it is preferable that the liquid contact start point is provided at an end portion of the application start position of the substrate. In this case, the liquid contact area can be expanded from the end of the application start position.

  The photomask blank of the present invention is a photomask blank including a substrate and a resist film formed by applying a resist solution to a surface to be coated of the substrate, and is applied when applying the resist solution. A liquid contact starting point portion used as a liquid contact starting point at one position on the coated surface of the resist solution at a start position is provided. According to this configuration, in the photomask blank manufacturing process, the resist film is generated when the resist liquid comes into contact with the coated surface of the substrate at one liquid contact start point, and comes into contact with liquid at a plurality of places. Bubbles can be prevented from being mixed into the resist film, and a resist film in which linear traces and film thickness fluctuations are suppressed can be formed. Therefore, the photomask blank having the liquid contact starting point portion has a uniform resist film having no linear trace.

  In the photomask blank according to the present invention, it is preferable that the liquid contact starting point is a protrusion provided on the surface to be coated of the substrate. In this case, when the resist solution comes into contact with the protrusions provided on the surface to be coated of the substrate, the wetted area is expanded starting from the wetted portion, and bubbles are prevented from being mixed into the resist solution. Can do. Therefore, the photomask blank having this protrusion has a uniform resist film in which linear traces and film thickness fluctuations are suppressed.

  The photomask blank of the present invention is a photomask blank including a substrate and a resist film formed by applying a resist solution to a surface to be coated of the substrate, and is applied when applying the resist solution. It is characterized in that there is provided an installation mark of a liquid contact starting point portion used as a liquid contact starting point at one place on the coated surface of the resist solution at a start position. According to this configuration, in the photomask blank manufacturing process, the resist film is generated when the resist liquid comes into contact with the coated surface of the substrate at one liquid contact start point, and comes into contact with liquid at a plurality of places. It is possible to prevent air bubbles from being mixed into the resist film and to form a resist film having no linear trace. Therefore, the photomask blank having the installation trace of the liquid contact starting point portion has a uniform resist film in which linear traces and film thickness fluctuations are suppressed.

  In the photomask blank according to the present invention, it is preferable that the installation mark of the liquid contact starting point is a notch of the resist film. In this case, a portion of the resist film is notched due to the presence of the protrusion provided as the liquid contact starting point, so that the photomask blank having the notched portion has linear marks and film thickness fluctuations. Thus, a uniform resist film having a suppressed thickness is provided.

  Further, the photomask manufacturing method of the present invention increases the resist solution by capillarity of a nozzle provided in the coating apparatus, and the resist solution is formed on the surface of the substrate facing downward with a light-shielding film formed. A step of preparing a photomask blank with a resist film manufactured by bringing the liquid into contact with the surface to be coated and moving the nozzle and the substrate relatively to form a resist film on the surface to be coated; A method for producing a photomask, comprising: forming a resist pattern by drawing a pattern on a resist film of a photomask blank with film and developing the resist pattern; and etching the light shielding film using the resist pattern as a mask. In the photomask blank with a resist film, the resist solution is provided on a surface to be coated of the substrate or a coating apparatus. Characterized in that it is one that is applied by liquid contact from one position of wetted origin. According to this method, the resist solution comes into contact with the coated surface of the substrate at one liquid contact origin, so that bubbles are mixed into the resist film and the film thickness varies when the liquid comes into contact with multiple locations. Can be prevented. Thereby, a resist film without a linear trace can be formed. Therefore, in a photomask manufactured with a uniform resist film, a metal light-shielding film pattern with a small error with respect to the target pattern can be obtained.

  The photomask of the present invention is a photomask including a substrate and a light shielding pattern formed on the surface of the substrate, and is used when a resist film is formed on the surface of the substrate in order to form the light shielding pattern. A liquid contact starting point portion used as a liquid contact starting point of the resist solution with respect to the substrate surface at a resist solution coating start position is provided. According to this configuration, in the photomask blank manufacturing process that is a pre-process of the photomask manufacturing process, the resist solution comes into contact with the coated surface of the substrate at one liquid contact starting point. It is possible to prevent bubbles from being mixed into the resist film and film thickness fluctuations that occur when the liquid is contacted with the film, and a resist film having no linear trace can be formed. Therefore, in this photomask, since the light shielding pattern is formed using a uniform resist film having no linear traces, a light shielding film pattern with a small error with respect to the target pattern can be obtained.

  In the photomask according to the present invention, it is preferable that the liquid contact start point is a protrusion provided on the surface of the substrate. In this case, in the photomask blank manufacturing process, which is a pre-process of the photomask manufacturing process, the resist liquid comes into contact with the protrusion provided on the coated surface of the substrate, so that the wetted part is As a starting point, the wetted area is expanded, and bubbles can be prevented from being mixed into the resist solution and film thickness fluctuation can be prevented. Therefore, in the photomask blank manufacturing process, a photomask blank having a uniform resist film free from linear traces and film thickness variations can be obtained. In a photomask manufactured from this photomask blank, a light-shielding pattern is formed using a uniform resist film without linear traces or film thickness fluctuations, so that a metal light-shielding with a small error with respect to the target accuracy of the pattern is formed. A film pattern can be obtained.

  The photomask of the present invention is a photomask including a substrate and a light shielding pattern formed on the surface of the substrate, and is used when a resist film is formed on the surface of the substrate in order to form the light shielding pattern. It is characterized in that there is an installation mark of a liquid contact starting point portion used as a liquid contact starting point of the resist solution on the substrate surface at a resist solution coating start position. According to this configuration, in the photomask blank manufacturing process that is a pre-process of the photomask manufacturing process, the resist solution comes into contact with the coated surface of the substrate at one liquid contact starting point. It is possible to prevent bubbles from being mixed into the resist film and variations in film thickness that occur when the liquid is brought into contact with the film, and it is possible to form a resist film having no linear traces or film thickness variations. Therefore, this photomask blank has a uniform resist film without linear traces or film thickness fluctuations. In a photomask manufactured from this photomask blank, a light-shielding pattern is formed using a uniform resist film having no linear traces or film thickness fluctuations. Obtainable.

  In the photomask according to the present invention, it is preferable that the installation mark of the liquid contact origin is a notch portion of a metal film that forms the light shielding pattern. In this case, in the photomask blank manufacturing process, which is a pre-process of the photomask manufacturing process, a part of the resist film is notched due to the presence of the protrusion provided as the liquid contact starting point. By performing development and etching processes in the photomask manufacturing process, notches are also formed in the light shielding film. As a result, a photomask having such a notch is a photomask manufactured from a photomask blank having a uniform resist film without linear traces, and therefore uses a uniform resist film without linear traces. Thus, a light shielding pattern is formed. As a result, a light shielding film pattern with a small error with respect to the target pattern is formed.

  Further, the coating apparatus of the present invention raises the resist solution by capillary action of the nozzle, brings the raised resist solution into contact with the coated surface of the substrate directed downward, and causes the nozzle and the substrate to move relative to each other. A coating apparatus for forming a resist film on the surface to be coated by moving the resist liquid and a surface to be coated of the substrate in one place. And According to this configuration, the resist solution contacts the coated surface of the substrate at one liquid contact origin, thereby preventing bubbles from being mixed into the resist film that is generated when the liquid is contacted at a plurality of locations. Can do. Thereby, a resist film without a linear trace can be formed.

  ADVANTAGE OF THE INVENTION According to this invention, the photomask blank which can form a uniform resist film by favorable liquid contact, a photomask, those manufacturing methods, and a coating device can be provided.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a side view showing a configuration of a coating apparatus according to an embodiment of the present invention. As shown in FIG. 1, the coating apparatus 1 includes a base frame 11, a coating unit 2 installed on the base frame 11, and a movement unit 4 that is supported so as to be movable on the base frame 11 and is moved in the horizontal direction. A moving frame 12, a suction means 3 provided on the moving frame 12 for sucking the substrate 10, and a holding means 5 for detachably holding the substrate 10. The application unit 2, the adsorption unit 3, the moving unit 4, and the holding unit 5 are controlled by a control unit (not shown).

  In the present embodiment, the substrate 10 is a photomask blank (size: 1220 mm × 1400 mm) in which a light-shielding film (a layer of metal chromium, oxide thereof, nitride, or the like) is formed on a transparent substrate. Is an apparatus for forming a resist film by applying a resist agent to the surface of the chromium layer of the transparent substrate 10. The photomask blank on which the resist film is formed is patterned on the resist film in a subsequent drawing process, and further a resist pattern is formed by a development process, and the etching process of the light shielding film using the resist pattern as a mask is performed. After that, it becomes a photomask.

  FIG. 2 is a cross-sectional view showing the configuration of the coating means 2 in the coating apparatus 1. As shown in FIG. 2, the coating means 2 raises the liquid resist agent 21 stored in the liquid tank 20 by capillary action in the capillary gap 23 of the coating nozzle 22, and covers the substrate 10 facing downward. The upper end portion of the application nozzle 22 is brought close to the application surface 10 a, and the resist agent 21 raised by the application nozzle 22 is brought into contact with the application surface 10 a through the upper end portion of the application nozzle 22.

  That is, the coating means 2 has a liquid tank 20 in which a liquid resist agent 21 is stored. The liquid tank 20 has a length corresponding to the length of one side in the lateral direction of the substrate 10, that is, the direction perpendicular to the direction moved by the moving frame 12 as will be described later (the direction perpendicular to the paper surface in FIG. 2). At least). The liquid tank 20 is attached to and supported by the upper end side of the support plate 24 so as to be movable in the vertical direction. The liquid tank 20 is moved up and down with respect to the support plate 24 by a drive mechanism (not shown). This drive mechanism operates under the control of the control unit.

  The support plate 24 is supported on the bottom frame 72 of the base frame 11 via linear ways 25 and 26 arranged orthogonal to each other on the lower end side. In other words, the position of the support plate 24 can be adjusted in two orthogonal directions on the bottom frame 72. A support column 28 that supports the application nozzle 22 housed in the liquid tank 20 is attached to the support plate 24 via a slide mechanism 27.

  FIG. 3 is a cross-sectional view illustrating a configuration of a main part of the coating unit 2 in the coating apparatus 1. As shown in FIG. 3, the support column 28 has its upper end side entered into the liquid tank 20 through a through hole 20 b provided in the bottom surface of the liquid tank 20. A coating nozzle 22 is attached to the upper end portion of the support column 28. The application nozzle 22 is supported by the support column 28 and is accommodated in the liquid tank 20. The coating nozzle 22 is configured to have a length corresponding to at least the lateral length of the substrate 10 (in the direction perpendicular to the paper surface in FIG. 3), and is slit along the longitudinal direction. A capillary gap 23 is formed. The coating nozzle 22 has a sharp cross-sectional shape with the capillary gap 23 interposed therebetween. The upper end portion of the capillary gap 23 is opened at the upper end portion of the application nozzle 22 in a slit shape over substantially the entire length of the application nozzle 22. The capillary gap 23 is also opened toward the lower side of the application nozzle 22.

  The slide mechanism 27 (FIG. 2) moves the support column 28 in the vertical direction with respect to the support plate 24 according to the control of the control unit by a drive mechanism (not shown). That is, the liquid tank 20 and the application nozzle 22 can move in the vertical direction with respect to the support plate 24 independently of each other.

  The upper surface of the liquid tank 20 is provided with a through-hole portion 20 a for projecting the upper end side of the application nozzle 22 to the upper side of the liquid tank 20. The peripheral portion of the through hole 20b on the bottom surface of the liquid tank 20 and the bottom surface of the coating nozzle 22 are connected by a bellows 29, and the resist agent 21 is prevented from leaking from the through hole 20b.

  In FIG. 1, the moving frame 12 is a mechanism that holds the substrate 10 by suction through the suction means 3 and moves the substrate 10 in the horizontal direction with respect to the coating means 2. This moving frame 12 is constructed by integrally connecting a pair of opposing side plates and a top plate for connecting these side plates, and the positional accuracy between the substrate 10 and the coating means 2 is distorted due to insufficient rigidity. It is configured with sufficient mechanical strength so that there is no problem.

  The moving frame 12 is supported by the base frame 11 via a linear way 41 installed on the base frame 11, and can be moved in the horizontal direction on the base frame 11. A moving member 13 is attached to one side plate of the moving frame 12. The moving member 13 is formed with a nut portion. A ball screw 42 constituting the moving means 4 attached to the base frame 11 is screwed into the nut portion of the moving member 13.

  An adsorption means 3 for adsorbing the substrate 10 is attached to a substantially central portion of the top plate of the moving frame 12 having an adsorption plate having a plurality of adsorption holes (not shown).

  The moving means 4 includes a ball screw 42 that is screwed into a nut portion of the moving member 13, and a motor 43 that rotates the ball screw 42. In the moving means 4, the motor 43 is driven in accordance with control by the control unit and rotates the ball screw 42. When the ball screw 42 is rotated in a predetermined direction by a predetermined number of rotations under the control of the control unit, the moving member 13 is horizontally moved with the moving frame 12 in a predetermined direction by a predetermined distance. .

  It should be noted that the vertical position (height) accuracy between the suction means 3 and the coating means 2 is the error of the distance (height) between the linear way 41 and the suction means 3, and the linear way 41 and the coating means 2. It is determined by the error in the distance (height) between them and the shape error of the linear way 41 itself.

  The holding means 5 first holds the substrate 10 carried from outside the coating apparatus in a state of being inclined substantially vertically (indicated by a broken line in FIG. 1), and then sets the substrate 10 in a horizontal state, This is a mechanism for delivering the to the suction means 3 attached to the moving frame 12. The holding means 5 receives the substrate 10 on which the application of the resist agent by the applying means 2 is completed from the suction means 3 and holds it in a horizontal state. Next, the substrate 10 is inclined substantially vertically. This is a mechanism for enabling the substrate 10 to be carried out of the coating apparatus.

  FIG. 4 is a front view showing the configuration of the coating apparatus 1. In the present embodiment, the carry-in side of the substrate 10 of the coating apparatus 1 is the front. As shown in FIGS. 1 and 4, the holding means 5 includes a base plate 69 and a rotation plate 65 supported on the base plate 69 so as to be rotatable between a horizontal state and a state inclined substantially vertically. And is configured.

  The holding means 5 includes four holding members 55 each fixed to the holding plate 61 via the linear way 64, the pair of rails 63, and the linear way 62 on the rotating plate 65. . These holding members 55 hold the peripheral portions of the four corners of the substrate 10.

  In the vicinity of each holding member 55, a pressing unit (not shown) is provided so that the substrate 10 set on the holding member 55 does not come off from the holding member 55. This pressing means is constituted by, for example, a pressing plate that can be moved up and down and rotated in the horizontal direction. This pressing means presses the substrate 10 set on the holding member 55 against the holding member 55 side.

  Two holding plates 61 are disposed on a pair of rails 63 disposed in a direction parallel to the linear way 41 on the base frame 11 indicated by an arrow Y in FIG. ing. The two holding plates 61 on the side close to the coating means 2 can be moved and operated in the direction of arrow Y in FIG. 1 by a driving means (not shown) having a ball screw and a motor. Thereby, even if the vertical dimensions of the substrate 10 are different, the two holding plates 61 are moved in the Y direction by the driving means so that the holding members 55 are opposed to the peripheral portions of the four corners of the substrate 10. Can do.

  Further, the pair of rails 63 are attached to the rotating plate 65 at both ends via linear ways 64 arranged in a direction orthogonal to the linear way 41 on the base frame 11 indicated by an arrow X in FIG. It has been. These rails 63 are movable in the direction of arrow X in FIG. 1 by a driving means (not shown) having a ball screw and a motor. Thereby, even if the lateral dimensions of the substrate 10 are different, the two holding plates 61 are moved in the X direction by the driving means so that the holding members 55 are opposed to the peripheral portions of the four corners of the substrate 10. Can do.

  The rotating plate 65 is supported at its end on the side far from the coating means 2 by a rotating shaft 66 so as to be rotatable with respect to the base plate 69. When the rotating plate 65 is in a horizontal state, the end near the coating means 2 is supported by a stopper 68 protruding from the base plate 69.

  The rotating plate 65 is rotated about the rotating shaft 66 by a rotating cylinder 67 attached to the base plate 69 at one end side. That is, the other end of the rotating cylinder 67 is connected to the rotating plate 65 and can be expanded and contracted.

  The base plate 69 has guide bars 71 protruding from the four corners of the lower surface. These guide bars 71 are passed through a holding means frame 70 fixed to the base frame 11. The base plate 69 can be moved up and down with respect to the holding means frame 70 while maintaining the horizontal state by the guide rods 71 being guided by the holding means frame 70. The base plate 69 can be moved up and down in the vertical direction by lifting means 73 such as an air cylinder installed on the bottom frame 72 of the base frame 11.

Next, a coating process of the coating apparatus 1 according to the present embodiment and a method for creating a liquid contact point in the coating process will be described. In the coating apparatus 1, from the state where the substrate 10 carried from the outside of the coating apparatus is held by the holding means 5 held in a substantially vertically inclined state, the substrate 10 is held by the holding means 5 while being held by the holding means 5. The liquid contact start point is provided on the application surface 10 a at the corner of the substrate 10 until it is transferred to the suction means 3 along with the rotation operation and the horizontal movement operation. However, the timing for providing the liquid contact start point is not particularly limited as long as it is before liquid contact.
As a member that functions as the liquid contact starting point, as will be described later, if the coating liquid supplied from the nozzle is surely first contacted and spreads along the nozzle starting from the contact point, The shape and material are not particularly limited. It is effective to have a raised portion from the coated surface of the substrate by a predetermined thickness (height). For example, a buffering adhesive material or the like can be used. As the adhesive material, a material having no reactivity with the resist is selected, and a material having elasticity such as a resin is preferable from the viewpoint of buffering property. The thickness of the adhesive material can be about 5 to 200 μm.

  FIG. 5 is a top view showing the tip of the substrate 10 and the application nozzle 22 that are held by the holding means 5 (FIG. 1) and move horizontally. In FIG. 5, the components other than the substrate 10 and the application nozzle 22 are omitted.

  The substrate 10 held horizontally has a light-shielding film (chrome layer 10b) formed on the lower surface to be coated 10a (FIG. 2), and the coating apparatus 1 has the surface to be coated 10a facing downward. In this state, the substrate 10 is moved horizontally in the direction of the arrow in the drawing by the holding means 5 to move across the coating nozzle 22. Then, the adhering material 101 is affixed to a region near the one end (corner) of the edge 10c of the substrate 10 and including the application start position on the surface to be applied. The edge portion 10 c is an edge portion in a direction orthogonal to the horizontal movement direction of the substrate 10. In the present embodiment, the coating nozzle 22 is opposed so as to match the longitudinal direction in a direction orthogonal to the horizontal movement direction of the substrate 10, and the substrate facing the longitudinal direction of the coating nozzle 22. The sticking material 101 is stuck at one place (application start point) in the vicinity of the ten edge portions 10c. Thereby, as will be described later, the resist solution 21 comes into contact with the substrate 10 at one liquid contact start point P1. Note that the one liquid contact start point P1 is a position where the resist solution 21 starts to be applied (in the case of FIG. 5, in the vicinity of the edge portion 10c of the substrate 10, specifically, from the edge portion 10c to the application direction, 0 to 5 mm). This means that the position is one place at a point on the inner side), and, as will be described later, when the application start position changes according to the carry-in direction of the substrate 10 with respect to the coating apparatus 1 (that is, the edge portion 10c of the substrate 10). In the case where the opposite edge 10g side becomes the application start position instead of the side), a liquid contact starting point may be further set accordingly. In this case, one liquid contact starting point can be provided on the edge 10g side in addition to the edge 10c side. That is, one liquid contact start point P1 at the application start position means one position at the application start position (the edge portion 10c side or the like), and a plurality of liquid contact start points P1 on the substrate 10. This is a concept that includes the provision of

  FIG. 6 is a front view showing the substrate 10 and the coating nozzle 22. As shown in FIG. 6, the adhesive material 101 is applied to the coated surface 10 a of the substrate 10, so that the portion of the coated surface 10 a where the adhesive material 101 is applied is compared to other regions. Projecting downward. That is, the part to which the sticking material 101 is stuck is closer to the application nozzle 22 than the other areas.

  In this state, when the coating nozzle 22 is raised and its tip is brought close to the coated surface 10a of the substrate 10, the bonding material 101 is affixed among the coating start positions set near the edge 10c of the substrate 10. The applied part (that is, the stuck adhesive 101) comes into contact with the resist agent 21 at the tip of the coating nozzle 22 first. 6 to 11, the chromium layer 10b (FIG. 5) is omitted.

  7 to 11 are front views showing the substrate 10 and the coating means 2 partially enlarged. Note that the drawings referred to in the present embodiment show these at different ratios from the actual dimensional relations of the respective parts in order to express the relations between the structural parts in an easily understandable manner.

  As shown in FIG. 7, when the coating start position of the substrate 10 is moved to above the coating nozzle 22, the coating apparatus 1 temporarily stops the horizontal movement of the substrate 10 at this position and raises the coating nozzle 22. The resist solution 21 held in the capillary gap 23 of the application nozzle 22 is raised at the tip of the application nozzle 22.

  Then, as shown in FIG. 8, as the application nozzle 22 is raised, the resist solution 21 first comes into contact with the adhesive material 101 attached to the substrate 10. Immediately after that, as shown in FIGS. 9 and 10, the resist solution 21 forms a straight line parallel to the edge portion 10 c (FIG. 5) of the substrate 10 indicated by an arrow from the position where it first contacts the adhesive material 101. The area in contact with the coated surface 10a of the substrate 10 is expanded along the line (that is, in the direction in which the nozzle extends). Thus, as shown in FIG. 11, a region where the coated surface 10 a of the substrate 10 and the resist solution 21 are in contact is formed over the entire coating start position of the substrate 10.

  That is, the position where the adhesive material 101 of the substrate 10 is adhered is defined as a liquid contact start point P1 with the resist solution 21, and contact is made in one direction along the edge 10c (FIG. 5) direction of the substrate 10 from the liquid contact start point P1. The liquid area expands. In this regard, when the resist solution 21 is in contact with the coated surface 10a of the substrate 10 without providing the liquid contact starting point P1 as in the prior art, the liquid contact is accidentally contacted at a plurality of locations along the coating nozzle 22. For example, the liquid contact area expands in a direction opposite to each other from two adjacent liquid contact start points, and bubbles are mixed into the resist liquid 21 at a portion where the liquid contact areas collide with each other. However, in the coating apparatus 1 according to the present embodiment, the liquid contact area expands in one direction starting from one liquid contact starting point P1, so that bubbles are mixed into the resist liquid 21 in contact with the substrate 10 and Instability of the liquid pool (meniscus) shape due to the impact of the collision can be prevented.

  In this way, the substrate 10 is further moved horizontally in the direction of the arrow shown in FIG. 5 with the resist solution 21 in contact with the tip of the coating nozzle 22 over the entire length of the coating start point of the substrate 10. A resist solution 21 is applied to the coated surface 10a. In this case, the resist solution 21 applied to the coated surface 10 a of the substrate 10 is prevented by preventing bubbles from entering the resist solution 21 at the application start point of the substrate 10 where the resist solution 21 is first contacted. In this layer, a uniform resist film can be formed without generating linear traces due to bubbles or the like.

  Then, when the substrate 10 on which the resist film is formed by the coating apparatus 1 is dried and then taken out from the coating apparatus 10 or in a subsequent process, a bonding material that becomes a liquid contact starting point is no longer necessary. The sticking material 101 is preferably removed from 10. For example, FIG. 12 is a partial bottom view showing the formation surface side (application surface 10a side) of the resist film 121 of the substrate 10 on which the resist film 121 formed by applying the resist solution 21 is formed. These are sectional views showing the AA line as a section. As shown in FIGS. 12 and 13, in the state where the resist film 121 is formed in the coating apparatus 1, the bonding material 101 exists on the coated surface 10 a near the corner of the substrate 10. And by removing the adhesive material 101 from this state, as shown in FIG.14 and FIG.15, the resist film 121 is not formed in the part from which the adhesive material 101 was removed, but the adhesive material 101 is affixed. The trace of the done area remains as a resist missing part (for example, a notch part K1).

  In the notch K1 formed in a part of the resist film 121, the chromium layer 122 forming the coated surface 10a of the substrate 10 is exposed because the resist film 121 is not formed. When the drawing process, the developing process, and the etching process are performed on the substrate 10 in this state, the etching process is performed on the portion where the chromium layer 122 is exposed, and the substrate 10 is exposed. That is, as shown in FIG. 16, the trace of the tape 101 remains in the chrome layer 122 as a notch K2.

  Thus, in the photomask blank 100 in which the resist film 121 is formed by providing the liquid contact start point P1 of the resist liquid 12 by using the adhesive material 101 by the coating method according to the present embodiment, the photomask blank 100 is attached to a part thereof. The adhering material 101 is in a state of being adhered as the liquid contact starting point P1 (FIG. 12), and further, in the photomask blank 100 after the adhering material 101 is removed, at the position where the adhering material 101 was present. A notch K1 remains as a missing portion of the resist film (FIG. 14). A uniform and good etching performance can be obtained by executing a drawing process, a resist developing process, and a light shielding film etching process using the formed resist pattern as a mask for the photomask blank 100. The photomask 110 in which the trace from which the tape 101 has been peeled remains in the chrome layer 122 as a notch K2 is completed (FIG. 16).

  FIG. 17 is a flowchart showing manufacturing steps of the photomask blank according to the present embodiment. As shown in FIG. 17, in the coating apparatus 1, the substrate 10 is loaded and set on the holding unit 5 (step ST <b> 11), and the holding unit 5 horizontally moves the substrate 10 while holding the substrate 10 horizontally. Move to the upper application position (step ST12). In this step, the coating apparatus 1 is positioned so that a predetermined position in the vicinity of the edge portion 10 c that is a coating start position of the substrate 10 is positioned above the coating nozzle 22. In this state, the application nozzle 22 is raised (step ST13). When the application nozzle 22 is raised, as described above with reference to FIGS. 7 to 11, the resist solution 21 comes into contact with the application surface 10a of the substrate 10 linearly from one liquid contact start point P1 (step ST14). When the resist solution 21 comes in contact with the entire length of the coating start position of the substrate 10, the coating nozzle 22 is slightly lowered to form an appropriate coating gap between the coating nozzle 22 and the coated surface 10a (step ST15). ). In this state, the substrate 10 is horizontally moved (that is, the substrate 10 and the application nozzle 22 are relatively moved), and the resist solution 21 is applied to the application surface 10a of the substrate 10 (step ST16). At this time, the nozzle may be moved instead of the substrate 10. Thereby, the resist solution 21 is applied to the substrate 10, and then the applied resist solution 21 is dried and carried out (step ST17). Thus, a photomask blank is manufactured by these processing steps.

  FIG. 18 is a flowchart showing a process of manufacturing a photomask using the photomask blank completed by the process of FIG. As shown in FIG. 18, in the photomask manufacturing process, first, a drawing process is performed on the resist film formed on the surface of the photomask blank (step ST21), followed by a development process of the resist film. The light shielding film is etched using the resist film as a mask (step ST22, step ST23). Thereby, a predetermined pattern is formed on the light shielding film. Finally, the resist film is peeled off (step ST24) to complete the photomask. FIG. 18 shows a process for a so-called binary mask in which a light-shielding pattern is formed by a light-shielding film on a transparent substrate. Depending on the application, the light-shielding film is laminated, or the light-shielding film and the semi-transparent film, Alternatively, it is of course possible to apply the present invention to a photomask having a laminated structure using another functional film. In that case, the photolithographic process is performed twice or more, and the resist solution coating method of the present invention can be applied to each of these processes, thereby obtaining a better effect.

  In the method of applying the resist solution 21 described above, a resist formed by applying the resist solution 21 by applying the adhesive 101 to the surface 10a to be applied of the substrate 10 and providing the contact point P1 of the resist solution 21. It is possible to prevent the occurrence of linear marks, film thickness non-uniformity, and the like in the film 121. Thereby, in the photomask blank 100 to which the adhesive material 101 has been applied and the photomask blank 100 in which the cutout portion K <b> 1, which is a trace from which the adhesive material 101 has been removed, is formed, a resist pattern formed in a subsequent process Therefore, it is possible to ensure the accuracy in the line width and the like, and to improve the yield.

  In addition, in the photomask 110 in which the cutout portion K2 that is a trace of the sticking agent 101 is formed, the development process is performed with the uniform resist film 121. Therefore, the thickness of the resist film 121 is increased. The error with respect to the target shape of the pattern of the chromium layer 122 generated due to non-uniformity is reduced.

(Second Embodiment)
In the first embodiment, the case where the adhesive material 101 is applied to the coated surface 10a of the substrate 10 to provide the liquid contact starting point P1 of the resist solution 21 has been described. However, the present invention is not limited to this. Alternatively, a protrusion other than the adhesive material may be provided on the coated surface 10 a of the substrate 10. For example, as shown in FIG. 19, a protrusion 10 d integrated with the substrate 10 is formed in advance on the coated surface 10 a at the corner of the substrate 10, and this protrusion 10 d is used as the liquid contact start point P <b> 1 of the resist solution 21. You can also. By providing the liquid contact starting point (protrusion 10d) integrated with the substrate 10 in this way, there is no need to remove the protrusion in a later step, and there is no inconvenience such as remaining adhesive used for pasting. There is.

  FIG. 20 is a cross-sectional view showing a photomask blank 200 having such protrusions. As shown in FIG. 20, in this photomask blank 200, a protrusion 10d is formed on the coated surface 10a of the substrate 10, and a resist film 121 is formed from a portion adjacent to the protrusion 10d. Thus, in the photomask blank in which the protrusions are formed, the protrusions become the liquid contact starting point P1 of the resist liquid 21 in the coating process of the resist solution 21, thereby forming a uniform resist film without linear traces. Will have.

(Third embodiment)
In the first embodiment, the case where the adhesive material 101 is applied to the coated surface 10a of the substrate 10 to provide the liquid contact starting point P1 of the resist solution 21 has been described. However, the present invention is not limited to this. Instead, a protrusion serving as the liquid contact starting point P1 may be provided on the coating nozzle 22 side of the coating apparatus 10.

  For example, as shown in FIG. 21, a protrusion 222 is formed in advance at one end of the application nozzle 22. The protrusion 222 is formed at the end of a region where the resist solution 21 is applied by the application nozzle 22, and the resist solution 21 held above the capillary gap 23 in this portion is held in another region. It is in a state where it rises more than the resist solution 21. As a result, when the coating nozzle 22 is raised to approach the coated surface 10 a of the substrate 10, the resist solution 21 on the protrusion 222 of the coating nozzle 22 first has the coated surface 10 a (edge portion 10 c) of the substrate 10. It contacts the end portion 10e) of FIG. And this contact part is made into the contact origin P1, and a contact area expands along the edge part 10c (FIG. 5) of the board | substrate 10. As shown in FIG. As a result, as in the case described above for the first embodiment, the liquid contact area is expanded from one liquid contact start point P1, and bubbles are generated in the resist liquid 21 in contact with the coated surface 10a of the substrate 10. Can be avoided.

  After the resist solution 21 on the projection 222 comes into contact with the coated surface 10a, the rising of the coating nozzle 22 is stopped (or the coating nozzle is lowered while leaving a gap between the projected portion 222 and the coated surface 10a). By forming an appropriate coating gap (distance between the nozzle and the surface to be coated) and horizontally moving the substrate 10 in this state, a resist film made of the resist solution 21 can be formed on the coating surface 10a of the substrate 10. it can.

(Other embodiments)
In the above-described embodiment, the case where the length of the coating nozzle 22 and the width of the coating area are the same has been described. However, the present invention is not limited to this, and the length of the coating nozzle 22 is the substrate. The present invention can be applied even when the width is longer than 10. Incidentally, when the protrusion 222 (FIG. 21) is provided on the application nozzle 22 side, the protrusion 222 and the end 10e (FIG. 21) of the edge 10c (FIG. 5) of the substrate 10 face each other. The positional relationship may be positioned.

  Further, in the above-described embodiment, the case where the liquid contact starting point P1 (the adhesive material 101 and other protrusions) is provided at the end portion 10e of the surface to be coated of the substrate 10 has been described, but the present invention is not limited thereto. It may be provided in a position other than the end portion. For example, as shown in FIG. 22, it may be provided in the vicinity of the central portion 10f of the edge portion 10c of the substrate 10. In this case, as shown in FIG. 23, when the liquid contact starting point P1 comes into contact with the coated surface 10a of the substrate 10 as the coating nozzle 22 rises, the substrate starts from the liquid contact starting point P1 as shown by an arrow in FIG. The liquid contact area is expanded in the direction of both ends of the ten edge portions 10c. Even in this case, it is possible to prevent bubbles from being mixed into the resist solution 21 in contact with the surface to be coated 10a by the resist solution 21 coming into contact with the surface to be coated 10a by one liquid contact starting point P1. Can do.

  In the above-described embodiment, the case where the liquid contact starting point P1 is provided at the application start position of the application surface 10a of the substrate 10 has been described. However, the present invention is not limited to this and is provided at another position. May be. For example, as shown in FIG. 24, in addition to the configuration in which a connection start point (a sticking material or a protrusion) is provided at one place (for example, near the end 10e) on the edge 10c side that is the application start position, the other edge It is good also as a structure which attaches a connection origin (an adhesive material or a projection part) also in one place (for example, edge part 10h vicinity) side of the part 10g side. If it does in this way, as the direction of the board | substrate 10 at the time of carrying in the board | substrate 10 in the coating device 1, either the edge part 10c side or 10g side can become an application | coating start position.

  In the above-described embodiment, the case of manufacturing a photomask blank having a size of 1220 mm × 1400 mm has been described. However, the present invention is not limited to this, and photomask blanks of various sizes are manufactured. Can be applied in case. In particular, the effect of the present invention is remarkable in a large mask having a side of 1000 mm or more. Even in such a blank for a large mask, for example, the film thickness variation after drying can be suppressed to 3% or less, and further to 2% or less. In the region up to the point where 30% of the area was applied, the film thickness variation could be suppressed to 1% or less.

  As mentioned above, although preferred embodiment was shown and demonstrated about the coating device and manufacturing method which concern on this invention, in this invention, it is not limited to embodiment mentioned above, In the range which does not deviate from the meaning of this invention, it is various. Needless to say, it is possible to implement this change.

  The present invention is applicable, for example, when manufacturing a photomask blank and a photomask for manufacturing a flat panel display (FPD).

The side view which shows the coating device which concerns on embodiment of this invention Sectional drawing which shows the structure of the coating means of the coating device of FIG. The expanded sectional view which shows the structure of the coating nozzle of the coating means of FIG. The front view which shows the structure of the coating device of FIG. Top view showing substrate and application nozzle Front view showing substrate and application nozzle Partial front view for explaining the operation of the resist solution in contact with the substrate Partial front view for explaining the operation of the resist solution in contact with the substrate Partial front view for explaining the operation of the resist solution in contact with the substrate Partial front view for explaining the operation of the resist solution in contact with the substrate Front view for explaining the operation of resist solution in contact with the substrate Partial plan view showing the state of application of the adhesive to the substrate Partial cross-sectional view showing a substrate to which an adhesive material has been applied The top view which shows the notch part of the resist film after the adhesive material is peeled off Sectional drawing which shows the notch part of the resist film after the adhesive material is peeled off The partial top view which shows the notch part of the metal light shielding film of the photomask manufactured by the manufacturing method of this invention The flowchart which shows the manufacturing process of the photomask blank by this invention Flow chart showing photomask manufacturing process Partial front view for explaining the liquid contact operation of the resist solution in the second embodiment The front view which shows the photomask blank manufactured by the coating method in 2nd Embodiment The partial front view with which it uses for description of the liquid-contact operation | movement of the resist liquid by the coating device which concerns on 3rd Embodiment The top view which shows the liquid contact origin by other embodiment The front view which shows the liquid-contact state of the resist liquid by the liquid-contact origin of FIG. Plan view showing the position of multiple wet contact points

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating device 2 Coating means 3 Adsorption means 4 Moving means 5 Holding means 10 Substrate 10a Surface to be coated 10c Edge 11 Base frame 12 Moving frame 20 Liquid tank 21 Resist liquid 22 Coating nozzle 23 Capillary gap 100, 200 Photomask blank 110 Photomask 121 Resist film 122 Shading chromium layer

Claims (13)

The resist solution is raised by capillary action of the nozzle provided in the coating apparatus, the raised resist solution is brought into contact with the coated surface of the substrate directed downward, and the nozzle and the substrate are relatively moved. And a method of manufacturing a photomask blank including forming a resist film on the coated surface,
A method for producing a photomask blank, comprising bringing the resist solution into contact with liquid from a liquid contact starting point provided on a surface to be coated of the coating apparatus or the substrate.   2. The method of manufacturing a photomask blank according to claim 1, wherein the liquid contact starting point is a protrusion provided on a surface to be coated of the substrate.   The method for producing a photomask blank according to claim 1, wherein the liquid contact starting point is provided at an end portion of the application start position of the substrate. A photomask blank including a substrate and a resist film formed by applying a resist solution to a surface to be coated of the substrate,
A photomask blank comprising a liquid contact starting point portion used as a liquid contact starting point at one place on the coated surface of the resist solution at a coating start position when the resist solution is applied.   The photomask blank according to claim 4, wherein the liquid contact starting point is a projection provided on the surface to be coated of the substrate. A photomask blank including a substrate and a resist film formed by applying a resist solution to a surface to be coated of the substrate,
A photomask blank comprising a placement mark of a liquid contact start point used as a liquid contact start point at one place on the coated surface of the resist liquid at a coating start position when the resist liquid is applied .   The photomask blank according to claim 6, wherein the installation mark of the liquid contact starting point is a notch of the resist film. The resist solution is raised by capillary action of a nozzle provided in the coating apparatus, and the raised resist solution is brought into contact with the coated surface of the substrate surface on which the light shielding film is formed and directed downward, and the nozzle and Preparing a photomask blank with a resist film manufactured by moving the substrate relative to each other and forming a resist film on the coated surface;
Forming a resist pattern by drawing a pattern on the resist film of the photomask blank with resist film and developing; and
And a step of etching the light-shielding film using the resist pattern as a mask.
The photomask blank with a resist film is
A method for producing a photomask, wherein the resist solution is applied by bringing the resist solution into contact with a surface to be coated of the substrate or a liquid contact starting point provided on a coating apparatus. A photomask including a substrate and a light shielding pattern formed on the surface of the substrate,
A liquid contact start point used as a liquid contact start point of the resist solution on the substrate surface at a resist solution coating start position when forming a resist film on the surface of the substrate to form the light shielding pattern A photomask comprising:   The photomask according to claim 9, wherein the liquid contact starting point is a protrusion provided on the surface of the substrate. A photomask including a substrate and a light shielding pattern formed on the surface of the substrate,
A liquid contact start point used as a liquid contact start point of the resist solution on the substrate surface at a resist solution coating start position when forming a resist film on the surface of the substrate to form the light shielding pattern A photomask characterized by comprising an installation mark.   The photomask according to claim 11, wherein the installation mark of the liquid contact starting point is a notch portion of a metal film that forms the light shielding pattern. The resist solution is raised by capillary action of the nozzle, the raised resist solution and the coated surface of the substrate directed downward are brought into contact with each other, and the nozzle and the substrate are relatively moved to move the coated solution. A coating apparatus for forming a resist film on a surface,
A coating apparatus, comprising: a liquid contact starting point portion that contacts the resist solution and a surface to be coated of the substrate at one place.

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