TW201732997A - Substrate holding device, drawing device, photomask inspection device, and method of manufacturing a photomask - Google Patents

Abstract

To provide a substrate holding device which is suitable for a photomask substrate and which is capable of improving a coordinate accuracy of a pattern to be formed on an object. A substrate holding device horizontally holds a photomask substrate for use in manufacturing a display device. The substrate holding device has a stage 11 of a low-expansion material, and a plurality of supporting members 12 provided on the stage 11. Each supporting member 12 has a contacting portion 14 formed at its end and having a convex curved surface. The contacting portion 14 is substantially brought into point contact with a back surface 3 of a photomask substrate 1 to thereby horizontally hold the photomask substrate 1.

Description

Substrate holding device, drawing device, mask inspection device, and method of manufacturing photomask

The present invention relates to a photomask for manufacturing an electronic component, and more particularly to a substrate holding device, a drawing device, a mask inspection device, and a photomask manufacturing method for holding a photomask substrate for manufacturing a flat panel display (FPD).

As a prior art, for example, Patent Document 1 describes a method of manufacturing a mask which estimates the shape of the film surface side in the drawing step and the shape change amount of the shape of the film surface side when the mask is exposed. Based on the calculated shape change amount, the design drawing data of the specific transfer pattern is corrected. Further, Patent Document 2 describes a substrate holding device that can reduce deformation and deflection caused by the weight of the substrate by blasting, and can appropriately mount and remove the substrate. [PRIOR ART DOCUMENT] [Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-134433 (Patent Document 2) Japanese Patent Laid-Open Publication No. 2005-101226

[Problems to be Solved by the Invention] In the manufacture of a flat type display device (flat panel display) typified by a liquid crystal display device or an organic EL (Electroluminescence) display device, etc. A mask for the transfer pattern of the component design. As a component, a display device mounted on a smart phone or a tablet terminal is required to be bright, power-saving, and fast in operation speed, and requires high image quality such as high resolution and wide viewing angle. Therefore, there is a demand for a high density and a high integration of the pattern of the photomask used for the above-described use, and it is strongly required that the pattern of the photomask to be used is made finer than previously. Further, a plurality of electronic components including a display device are three-dimensionally formed by a laminate of a plurality of layers in which a fine pattern is formed. Therefore, the improvement of the coordinates of the plurality of layers and the integration of the coordinates of each other become important. In other words, if the pattern coordinate accuracy of each layer does not satisfy a certain level, it may cause a problem that an appropriate operation cannot be ensured in the completed component. Therefore, the tolerance range of the coordinate offset required for each layer is becoming smaller and smaller. The coordinate accuracy refers to an index for evaluating how much the position of the transfer pattern formed on the substrate is shifted from the coordinate position specified by the design. The coordinates accuracy is the evaluation as the offset is smaller. The photomask is produced by forming a transfer pattern on the main surface of the substrate including the transparent material. Specifically, first, a reticle substrate is prepared, which is formed on a smooth and flat processed transparent material substrate to form an optical film having desired optical properties, and further, is coated with a photosensitive material film such as a photoresist. Made. Next, a design pattern is drawn using the drawing device on the mask base. Then, the resist pattern obtained by development is used as an etching mask, and the optical film is etched to obtain a desired transfer pattern. Then, it is also possible to form a complicated transfer pattern by repeating film formation, resist pattern formation, and etching as needed. The display device is manufactured by transferring the transfer pattern to a display panel substrate or the like as a transfer target. However, it is not easy to ensure a certain coordinate accuracy on the transferred body. One of the reasons is that the shape of the film surface in the drawing step of the reticle base drawing pattern does not necessarily coincide with the shape of the film surface in the exposure step using the reticle having the obtained transfer pattern. Therefore, the coordinate accuracy of the drawn pattern sometimes deteriorates at the time of transfer. For example, when the pattern is drawn using the drawing device on the mask base, the mask base is placed on the stage of the drawing device with the film surface facing upward. At this time, when the flatness of the stage is insufficient or the flatness of the back surface of the reticle base opposite to the stage is insufficient, the unevenness affects the surface shape of the reticle base, and Drawing is performed in this state. Specifically, for example, the front surface 52 of the substrate for a mask (hereinafter, simply referred to as "substrate") 51 as shown in FIG. 8(a) is a film surface, and the flatness of the back surface 53 on the opposite side is insufficient. In the case where the substrate 51 is placed on the stage 61 with the front surface 52 as the film surface facing upward as shown in FIG. 8(b), the back surface 53 of the substrate 51 is patterned by the gravity of the stage 61. 62. The shape of the front surface 52 of the substrate 51 is affected by the unevenness of the back surface 53. Further, even if the plane 62 of the stage 61 is a flat surface having no unevenness, and the substrate 51 having a high degree of flatness with a very high flatness of the back surface 53 is used, it is generated between the plane 62 of the stage 61 and the back surface 53 of the substrate 51. When the foreign matter 63 is sandwiched, the film surface shape (front surface shape) of the substrate 51 changes due to the influence thereof. On the other hand, when the transfer pattern is formed by patterning or the like and the photomask which is a finished product is placed on the exposure apparatus, the upward film surface becomes downward at the time of drawing, and is not in contact with the stage. The state in which the change in the shape of the above-mentioned film surface disappears. Therefore, the shape of the film is different between the drawing and the exposure, and the coordinate accuracy at the time of exposure is deteriorated due to the influence. The technique described in Patent Document 1 solves the difference between the shape of the film surface at the time of drawing and the time of exposure by the correction of the drawing data. In other words, in order to cancel the coordinate offset originating from the difference in the shape of the film surface at the time of drawing and the time of exposure, the coordinates to be applied at the time of drawing or drawing are corrected in advance, thereby preventing the coordinate accuracy at the time of exposure from deteriorating. However, the following method is also considered to be a more fundamental method for maintaining the coordinate accuracy of the reticle higher. The method is for suppressing the deformation factor itself of the film surface of the substrate in the drawing device, and is set to be close to the ideal plane. Thereby, the necessity of correcting the above-described depiction data is reduced or eliminated. The substrate holding device described in Patent Document 2 is provided with a convex portion on the upper surface of the stage and a discharge hole for blowing a gas to the lower surface of the substrate, the convex portion having a mounting surface on which the substrate is placed, and a substrate for adsorbing and holding the substrate The holding device reduces the deflection of the substrate due to its own weight by blowing gas from the substrate from below. However, in the substrate holding device, there is a risk that deformation of the substrate occurs due to pinching of foreign matter between the convex portion and the substrate or adsorption of the substrate. Therefore, the present invention has been made to solve the above problems, and it is desirable to provide a substrate holding device, a drawing device, a mask inspection device, and a mask that are suitable for a mask substrate, which can improve the coordinate accuracy of a pattern formed on a transfer target. Manufacturing method. [Means for Solving the Problem] (First Aspect) A substrate holding device according to a first aspect of the present invention is characterized in that: the photomask substrate for manufacturing a display device is horizontally held, and includes: a table comprising a low expansion material; and a plurality of support members disposed on the stage; wherein the support member has a contact portion having a convex curved surface at the front end, and the contact portion is substantially in point contact or line contact with the above The lower surface side main surface of the photomask substrate, whereby the above-described photomask substrate is horizontally held. According to a second aspect of the invention, in the substrate holding device according to the first aspect of the invention, the support member includes a spherical contact portion at a distal end, and the contact portion is substantially in point contact with The lower surface main surface of the mask substrate. (Third Aspect) The substrate holding device according to the first or second aspect of the present invention is characterized by comprising: a floating mechanism for leveling the stage in a non-contact state The ground is kept on the abutment. (4th aspect) The substrate holding device according to any one of the first to third aspects of the present invention, characterized in that the plurality of support members are 150 mm apart from each other. The following methods are arranged on the above stage. (Fifth Aspect) The substrate holding device according to any one of the first to fourth aspects of the present invention, characterized in that the plurality of support members each have a height adjustment mechanism. (6th aspect) The sixth aspect of the invention is the substrate holding device according to the fifth aspect, wherein the height adjusting mechanism uses a pressure of a gas. (Seventh Aspect) The seventh aspect of the invention is the substrate holding device according to the fifth aspect, wherein the height adjusting mechanism uses a repulsive force based on a magnetic force. According to a ninth aspect of the present invention, in the substrate holding device of the fifth aspect, the height adjusting mechanism includes a driving device that adjusts the contact portion according to a height adjustment amount. Height position. (9th aspect) A ninth aspect of the invention is a drawing device comprising the substrate holding device according to any one of the first to eighth aspects described above. (10th aspect) A ninth aspect of the invention is a reticle inspection apparatus comprising the substrate holding device according to any one of the first to eighth aspects described above. (11th aspect) The eleventh aspect of the invention is a method of manufacturing a photomask, comprising the steps of: preparing a photomask formed by forming an optical film and a photoresist film on a main surface of a photomask substrate comprising a transparent material; a substrate holding device according to any one of the first to seventh aspects described above, wherein the photomask substrate is held; and the photomask substrate is imaged based on pattern data, and the optical film is formed Patterned. (12th aspect) A twelfth aspect of the invention is a method of manufacturing a photomask comprising the steps of: preparing a photomask formed by forming an optical film and a photoresist film on a main surface of a photomask substrate comprising a transparent material; Forming the mask base based on pattern data, patterning the optical film to form a mask having a transfer pattern; and inspecting the transfer pattern; and performing the following steps in the inspection step In other words, the reticle is held by the substrate holding device according to any one of the first to seventh aspects described above, and the coordinate accuracy is checked. (13th aspect) A thirteenth aspect of the invention is a method of manufacturing a photomask, comprising the steps of: preparing a photomask formed by forming an optical film and a photoresist film on a main surface of a photomask substrate comprising a transparent material; a substrate holding step of holding the photomask substrate on the upper side of the main surface by a substrate holding device; and a drawing step of drawing the mask substrate based on the pattern data; The substrate holding device includes: a stage on which the photomask substrate is placed; and a plurality of support members provided on the stage and each having a height adjustment mechanism; and the holding step includes the following steps, that is, And measuring a height distribution of the main surface to obtain height distribution data, and driving the height adjustment mechanism to adjust a shape of the main surface of the mask base based on the height distribution data. [Effects of the Invention] According to the present invention, it is possible to suppress a change in the shape of the mask film caused by the sandwiching of the foreign matter on the stage of the mask substrate, and to make the transfer pattern included in the mask an excellent coordinate. The precision is transferred to the transferred body.

In general, in order to draw a reticle base or the like, a substrate holding device that holds a substrate horizontally is used. The substrate holding device includes a stage that is flat and smoothly processed as a stage on which the substrate is placed. Further, in the case where the substrate is actually held, the substrate is placed on the stage with the surface of the film surface facing upward. In the present specification, the film surface refers to the following surfaces of the two main surfaces of the substrate in the relationship between the front surface and the back surface. That is, if it is a substrate containing a transparent material before pattern formation, it means a predetermined surface on which a pattern is to be formed, and if it is a mask base on which a specific optical film or a resist film is formed, it means that these are formed. The surface of the film is a mask on which a transfer pattern is formed, or a mask intermediate as a semi-product thereof. Further, the main surface conforming to the film surface was set to the front surface, and the main surface opposite to the film surface was set as the back surface. Here, the surface of the stage of the substrate holding device is clean and is an ideal plane. If the front surface (film surface) and the back surface of the substrate placed thereon are also ideal planes, there is no problem that the coordinate accuracy is deteriorated. However, even if the two main surfaces are precisely ground at the stage of preparing the substrate for the photomask, for example, when the flatness of the back surface is insufficient or when there is a foreign matter between the stage and the substrate, Affected by these factors, the shape of the film surface of the substrate placed on the stage changes (see Fig. 8). Therefore, when the film surface side of the substrate is drawn by the specific pattern data in a state where the film surface shape changes as described above, the transfer pattern formed thereby is transferred to the image by the exposure device. In the transfer of the transfer body, that is, in the state where the change in the shape of the film surface due to the unevenness on the back side or the foreign matter disappears, the coordinate accuracy is lost and deformation occurs. Of course, the deterioration of the coordinate accuracy can be somewhat reduced by using a substrate that is polished with high precision. For example, when a substrate having high precision which is processed not only on the film surface side of the substrate but also on the back surface side is used, it is possible to suppress a change in the film surface shape at the time of drawing. However, the presence of foreign matter that occurs sporadically on the stage of the substrate holding device cannot be completely excluded. Therefore, in the present embodiment, in order to further suppress deterioration of coordinate accuracy due to the presence of such foreign matter, the contact between the back surface of the substrate and the stage is substantially in point contact or line contact, and the foreign matter is prevented from being caught. Probability. Specifically, the substrate holding device of the present embodiment holds the mask substrate for manufacturing the display device horizontally, and includes a stage including a low expansion material, and a plurality of support members, which are provided in the carrier On the stage. Further, each of the support members has a configuration in which a contact portion having a convex curved surface is provided at the tip end, and the contact portion is substantially in point contact or line contact with the main surface on the lower surface side of the photomask substrate, whereby the photomask substrate is used. Keep it horizontally. In the present specification, the photomask substrate to be held (hereinafter also referred to as "mask substrate" or simply "substrate") may be a substrate containing a transparent material, or may be any of the substrates. The surface film is suitable for the desired optical film for the transfer pattern to be obtained (including a light-shielding film that shields the exposed light, a semi-transmissive film that partially transmits the exposed light, partially transmits the exposed light, and makes the light a phase shift film having a phase shift, an antireflection film for preventing reflection of light including exposed light, or a mask base formed by a functional film (etching stopper film, conductive adjustment film, etc.) A resist substrate having a resist formed with a resist film such as a photoresist may be a mask intermediate or a mask partially or completely formed with a transfer pattern. [First Embodiment] Fig. 1 is a view for explaining a configuration of a substrate holding device according to a first embodiment of the present invention, wherein (a) is a side view showing a state of a photomask substrate before holding, and (b) is a view showing A side view of the state in which the mask substrate is held by the substrate holding device. (Photomask Substrate) The photomask substrate 1 shown in Fig. 1(a) is a photomask substrate in which a front surface 2 as a main surface is a film surface, and a light shielding film or the like is formed thereon. The mask substrate 1 is formed in a quadrangular shape (square or rectangular shape) in plan view. Further, the mask substrate 1 exemplified herein has a shape as shown in FIG. 1(a) when the flatness is measured without being deflected by its own weight. In the illustrated photomask substrate 1 , the substrate is polished with high precision so that the flatness of the front surface 2 is increased. However, there are a plurality of irregularities on the back surface 3 . As a method of measuring the flatness without being affected by the deflection caused by its own weight, for example, there is a method of vertically holding the main surfaces (front and back) of the substrate, and in this state, by flatness, respectively The flatness of the front and back sides of the substrate is measured by a measuring device or the like. The front surface and the back surface of the substrate can be grasped by setting the measurement result obtained by the method to the front flatness data and the back surface flatness data, and performing mapping. (Substrate Holding Device) The substrate holding device 10 shown in Fig. 1(b) holds the mask substrate 1 horizontally. The substrate holding device 10 is provided with a stage 11 . The stage 11 is made of a material processed into a plate shape, and preferably contains a low expansion material. Low expansion materials are materials that have a small volume change due to temperature changes. For example, in the case of ceramics or the like, a material having a very low coefficient of thermal expansion near normal temperature can be preferably used. Preferably, the coefficient of thermal expansion is 0 to 50 degrees Celsius, 0.1×10 ^-6 A material of /K or less is used as a constituent material of the stage 11. In the present specification, the expression "○○ to △△" in the numerical range of the predetermined value means "○○ or more and ΔΔ or less". The stage 11 is formed in a quadrangular shape (square or rectangular shape) in the same manner as the mask substrate 1. A plurality of support members 12 are disposed on the stage 11. Each of the support members 12 is a support member having a columnar pin structure (hereinafter also referred to as a "support pin"), and is provided in a state of being protruded upward from the surface (upper surface) of the stage 11 . Each of the support pins is fixed to the stage 11, and the height of the support pins is fixed (this is referred to as a height-fixed type). Here, the support pin is set to a fixed height. At the front end of each of the support members (support pins) 12, a contact portion 14 having a convex curved surface on the upper side is formed. The contact portion 14 is a portion that comes into contact with the back surface (lower surface) 3 of the mask substrate 1 when the mask substrate 1 is held by the substrate holding device 10. The contact portion 14 is made of a hard material. The contact portion 14 is, for example, a portion that is substantially in point contact with the back surface 3 of the mask substrate 1 by attaching the contact portion 14 formed in a spherical shape (spherical shape) to the front end of the support pin. Actually, the back surface 3 of the lower main surface of the substrate is supported by the plurality of support members 12 in a substantially point-contact manner with the back surface 3 of the substrate facing downward and the photomask substrate 1 placed on the stage 11. At the front end, the mask substrate 1 is horizontally held in this state. Furthermore, the contact portion having the convex curved surface and the back surface of the substrate are in point contact in principle, and when the contact portion is slightly deformed by the weight of the substrate, the contact is also substantially in point contact, and the effect of the present invention is obtained. Therefore, the present invention encompasses this state. The same applies to the following line contact. At this time, a plurality of support members (support pins) 12 support the weight of the substrate from the back surface 3 side of the mask substrate 1 via the contact portion 14, whereby the mask substrate 1 is horizontally held. Further, when at least four holders 12 are disposed on the stage 11, the mask substrate 1 contacts the side of the support back surface 3 at a point of at least four points, and supports the weight thereof. As the material of the contact portion 14, a hard material such as ruby or sapphire can be preferably used. However, in addition to this, the contact portion 14 may be formed of a metal having a relatively high hardness. For example, it is preferred to use a Vickers hardness of 800 kgw/mm. ² The above material. When the contact portion 14 is formed of a material having a low hardness, the point contact cannot be maintained due to abrasion, and it is necessary to replace it repeatedly. On the other hand, when the contact portion 14 is formed of a material having a high hardness, abrasion of the contact portion 14 can be suppressed, so that the state of point contact can be maintained for a long period of time. Further, as shown in FIG. 2(a), the substrate holding device 10 of the present embodiment includes a base 15 under the stage 11. The base 15 is formed into a quadrangular shape (square or rectangular shape) in the same manner as the stage 11 . The stage 11 is placed horizontally on the base 15, and more preferably has a function of being horizontally held on the base 15 in a non-contact state. Specifically, for example, it is possible to provide a configuration in which the stage 11 is lifted by the pressure of the gas or the like, and the stage 11 is horizontally held in the non-contact state by the floating mechanism. 15 on. In this case, the stage 11 is preferably configured to be floated by the pressure of the gas (for example, air pressure) while maintaining the horizontal posture on the base 15. Therefore, for example, in the case where the drawing device must hold the stage 11 of the mask substrate 1 horizontally, the stage 11 can be floated from the base 15 to a specific height as indicated by an arrow in the drawing. In this state, the stage 11 is horizontally moved. As shown in FIG. 2(b), the support member 12 has a contact portion 14 having a convex curved surface (a spherical surface in the present embodiment) at the tip end. The support members 12 are preferably regularly arranged on the stage 11 at a fixed distance. In this case, it is preferable that the plurality of support members 12 are arranged on the stage 11 at intervals of 150 mm or less, more preferably 60 to 150 mm, and still more preferably 60 to 130 mm. In FIG. 2(a), as an example, a plurality of support members 12 are arranged in a lattice shape on the stage 11. In the case where the support member 12 is constituted by the support pins, it is preferable that the support pins are regularly arranged such that the interval between the adjacent support pins (the distance between the centers) becomes 150 mm or less as described above. Further, in the case where the support member 12 is constituted by the support pins, it is preferable that at least four support pins are provided on the stage 11. In this case, the contact portion 14 of the support member 12 is contacted with respect to at least four points on the back surface 3 opposed to the stage 11 with respect to the mask substrate 1 held by the substrate holding device 10. Further, by the contact of the four points, the weight of the mask substrate 1 is supported by the respective support members 12. Here, if the number of the support pins disposed on the stage 11 with respect to the size or weight of the mask substrate 1 is too small, the substrate may be deflected between the support pins and adversely affect the coordinate accuracy. . Further, if the number of supporting pins is too large, the number of contact points between the supporting pin and the substrate is increased accordingly, and the probability that the foreign matter is interposed between the supporting pin and the substrate is increased. In particular, the mask substrate for manufacturing a display device has a square or rectangular shape of 300 mm or more on one side of the main surface, and has a large area and a weight. Therefore, it is difficult to support with contact of 3 points or less. Therefore, in the case where the photomask substrate for manufacturing the display device is supported by the point contact by the support pin, it is preferably supported at a contact point of preferably 9 to 350 dots, more preferably 36 to 300 dots. As described above, the height of each contact point can be set equal. Alternatively, the back flatness data may be adjusted to adjust the height of each contact point so as to offset the height distribution of the back surface. In the first embodiment, when the mask substrate 1 is horizontally held by the substrate holding device 10, the plurality of support members 12 provided on the stage 11 are respectively passed through the contact portion 14. It is in point contact with the back surface of the mask substrate 1 at three points. According to this configuration, the back surface 3 side of the mask substrate 1 is not placed on the stage 11 in surface contact, and the mask substrate 1 is held as the upper surface of the stage 11 by a plurality of support members 12. Since it is in a floating state, the foreign matter 16 is not interposed between the upper surface of the stage 11 and the back surface of the mask substrate 1 (FIG. 1). Further, since the mask substrate 1 is supported in contact with each of the holders 12, it is less likely to cause foreign matter to be caught between the back surface of the mask substrate 1 and the tip end of the holder 12. Therefore, when the processing on the film surface side of the mask substrate 1 (for example, drawing processing) is performed in this state, it is possible to suppress a change in the shape of the film surface caused by the insertion of the foreign matter 16. Thereby, deterioration of coordinate accuracy due to a change in the shape of the film surface can be suppressed. As a result, the transfer pattern formed on the mask substrate 1 can be transferred to the object to be transferred with excellent coordinate accuracy. As described above, in the first embodiment, it is possible to suppress a change in the shape of the film surface of the mask substrate 1 caused by the sandwiching of the foreign matter 16, thereby suppressing a difference in the shape of the film surface during drawing and exposure. Degradation of coordinate accuracy. Thereby, it is possible to prevent the risk of deformation of the mask substrate 1 due to the insertion of the foreign matter 16, and to achieve the desired purpose of improving the coordinates of the pattern formed on the transfer target. However, in the case where the back surface 3 of the photomask substrate 1 is caused by irregularities having insufficient flatness, a further design for suppressing the influence thereof can be performed. In other words, when the flatness of the back surface 3 is insufficient and the back surface 3 has irregularities, the unevenness is reflected on the film surface side of the mask substrate 1 placed horizontally on the stage 11 of the substrate holding device 10. Therefore, there is a problem that the coordinate accuracy after the processing (for example, the drawing process) of the substrate film surface performed in this state is adversely affected. Therefore, the inventors of the present invention have conceived a substrate holding device which can obtain higher coordinate accuracy than the above-described first embodiment. Hereinafter, specific aspects will be described as the second embodiment and the third embodiment. (Second Embodiment) Fig. 3 is a view for explaining a configuration of a substrate holding device according to a second embodiment of the present invention, wherein (a) is a side view showing a state of the photomask substrate before holding, and (b) is a view showing A side view of the state in which the mask substrate is held by the substrate holding device. (Photomask Substrate) The photomask substrate 1 shown in Fig. 3 (a) is a film surface on which the front surface 2 as a main surface is formed, and a light-shielding film or the like is formed thereon. Photomask base. However, the flatness can be made flater than the mask substrate 1 used in the first embodiment. In other words, the flatness of the front surface 2 is as high as that of the first embodiment when the flat mask 1 is exemplified in the state where the flat mask 1 is not subjected to the deflection due to its own weight, but the back surface 3 is The unevenness is larger than that of the first embodiment, and the thickness of the substrate becomes uneven. (Substrate Holding Device) In the substrate holding device 10 shown in FIG. 3(b), a plurality of holders 12 are provided on the stage 11 including the low expansion material. This aspect is the same as that of the first embodiment described above. However, in the first embodiment, the height of the support pins constituting each of the support members 12 is fixed. In the second embodiment, the height adjustment mechanism 20 is provided in each of the support members 12. The height adjustment mechanism 20 adjusts the height position of the contact portion 14 in the support member 12 by the pressure of the gas (for example, air pressure or the like). In the height adjustment mechanism 20, as a driving device for adjusting the height position of the contact portion 14, for example, as shown in FIG. 4, an air damper 21 is provided, and the air damper 21 can be supplied to and from the air damper 21 Move the rod 22 in the direction. At the front end (upper end) of the rod 22, a spherical contact portion 14 is attached to the protrusion 23. The ball-shaped contact portion 14 is vertically movable in accordance with the load received. Here, as an example, the height adjustment mechanism 20 uses a pressure of a gas, but is not limited thereto. For example, a force based on a magnetic force may be used. In the height adjusting mechanism 20 including the above configuration, the rod 22 is moved (up and down) in the vertical direction by supplying compressed air to the air damper 21 or exhausting the supplied compressed air. Further, in a state where a load is applied to the contact portion 14, the height of the contact portion 14 can be adjusted (changed) by the pressure of the compressed air supplied to the air damper 21 by variable control. When the compressed air is supplied to the air damper 21 of the height adjusting mechanism 20 while the photomask substrate 1 is not placed on the stage 11, the contact portion 14 is pushed up by the rise of the rod 22. At this time, the thrust acts on the contact portion 14 of the support member 12 corresponding to the pressure of the compressed air. Therefore, by supplying the compressed air of the same pressure to the height adjusting mechanisms 20 of all the support members 12 provided on the stage 11, the contact portions 14 of the respective support members 12 can be raised by the same upper thrust force. When the substrate holding device 10 having the above configuration is used to hold the mask substrate 1, the mask substrate 1 is placed on the stage 11 with its front surface 2 facing upward and the back surface 3 facing downward. In this manner, as in the first embodiment, the mask substrate 1 is supported in contact with each of the holders 12 provided on the stage 11 via the contact portion 14. When the compressed air is supplied to the height adjusting mechanism 20 of each of the holders 12 and the contact portion 14 is raised, and the mask substrate 1 is downloaded in this state, the support member 12 is applied downward by the mask substrate 1 itself. The weight caused by the weight. At this time, in each of the holders 12, the contact portion 14 is stationary at a height position at which the thrust acting on the contact portion 14 via the rod 22 and the gravity acting on the contact portion 14 due to the weight of the mask substrate 1 are balanced. Therefore, when the photomask substrate 1 is placed on the stage 11, the gravity caused by the weight of the photomask substrate 1 and the upper thrust generated by the height adjusting mechanism 20 are balanced (substantially equal). The mode may set the pressure of the compressed air supplied to each height adjustment mechanism 20. In the second embodiment, the configuration is such that compressed air is supplied to the respective height adjustment mechanisms 20 at equal pressure. Therefore, even when the flatness of the back surface 3 of the mask substrate 1 is insufficient and there is unevenness on the back surface 3, the contact portion 14 of each of the support members 12 can be maintained while maintaining the uneven shape of the back surface 3. The photomask substrate 1 is horizontally supported. The reason is as follows. On the back surface 3 of the mask substrate 1, a portion having a relatively large thickness (a portion having a large weight per unit area) and a portion having a relatively small thickness (a portion having a small weight per unit area) are present due to the unevenness. In the case where compressed air is supplied to the respective height adjusting mechanisms 20 at equal pressures, the contact portion 14 which is in contact with the portion having a relatively large thickness is subjected to greater gravity, and is therefore stationary at a relatively low position. On the other hand, the contact portion 14 which is in contact with a portion having a relatively small thickness as described above is subjected to a smaller gravity and is therefore stationary at a relatively higher position. That is, the height positions of the contact portions 14 are different depending on the unevenness of the back surface 3 of the mask substrate 1. Therefore, the height of the contact portion 14 can be adjusted depending on the shape of the back surface of the substrate to be used (passively). This is also the case when the mask substrate 1 is placed on the stage 11 and the compressed air is supplied to the height adjustment mechanism 20 at equal pressure. Therefore, in the second embodiment, even if irregularities are present on the back surface 3 of the cover substrate 1, the unevenness can be absorbed by the difference in height position of each contact portion 14. Therefore, the uneven shape of the back surface 3 of the mask substrate 1 is not reflected on the front surface (film surface) 2 side, and the mask substrate 1 can be horizontally held. Further, even if the foreign matter 16 existing on the stage 11 or the unevenness due to the flatness of the back surface 3 is insufficient, the influence can be reduced and the level (flatness) of the film surface can be maintained at a higher level. Further, when processing (for example, drawing processing) of the mask substrate 1 placed on the substrate holding device 10, deterioration of coordinate accuracy can be further suppressed. (3) FIG. 5 is a view for explaining a configuration of a substrate holding device according to a third embodiment of the present invention, wherein (a) is a side view showing a state of the photomask substrate before holding, and (b) is a view showing (c) is a side view showing a state in which the substrate holding device holds the mask substrate without driving the height adjusting mechanism, and (c) is a side view showing a state in which the height adjusting mechanism is driven to hold the mask substrate by the substrate holding device. (Photomask Substrate) In the same manner as in the second embodiment, the mask substrate 1 shown in Fig. 5(a) is a film surface on which the front surface 2 as a main surface is formed, and a light shielding film or the like is formed thereon. Photomask base. When the flat mask is measured in a state where the flatness of the front surface 2 is not affected by the deflection due to its own weight, the flatness of the front surface 2 is higher than that of the first embodiment, but the unevenness of the back surface 3 is smaller than that of the first embodiment. Large, and the thickness of the substrate becomes uneven. (Substrate Holding Device) In the substrate holding device 10 shown in FIGS. 5(b) and 5(c), a plurality of holders 12 are provided on the stage 11 including the low expansion material, and the support members (support pins) 12 are provided. A height adjustment mechanism 20 is provided. This aspect is the same as that of the second embodiment described above. However, in the third embodiment, the second embodiment differs from the second embodiment in that each of the plurality of support members (support pins) 12 is provided with a height adjustment mechanism 20 that can independently adjust the height. That is, each of the plurality of height adjustment mechanisms 20 corresponding to the plurality of holders 12 includes a drive device that raises the position of the contact portion 14 in accordance with the designated height adjustment amount (actively). Specifically, for example, the air damper 21 and the rod 22 shown in FIG. 4 described above are used to constitute the driving device of the height adjusting mechanism 20, whereby the height adjusting mechanism 20 is a pressure using gas (here, air pressure is used). The height of the contact portion 14 is adjusted so that the pressure of the compressed air supplied to the air damper 21 can be individually controlled for each of the height adjusting mechanisms 20. Thereby, when the mask substrate 1 is horizontally held, the height of the contact portion 14 of the plurality of holders 12 can be independently adjusted. Further, the position of the contact portion 14 can be raised at a desired upper thrust force in accordance with the specified height adjustment amount for each of the support members 12, respectively. Here, a case is considered in which, as shown in FIG. 5(b), when the mask substrate 1 is held by the substrate holding device 10 without driving the height adjusting mechanism 20, in a portion, the support member 12 is provided. Foreign matter 16 is interposed between the contact portion 14 and the back surface 3 of the mask substrate 1. In this case, there is a risk that the unevenness of the back surface 3 of the mask substrate 1 shown in FIG. 5(a) and the foreign matter 16 shown in FIG. 5(b) cause the unevenness or foreign matter on the back surface 3 side. The sandwiching of 16 is reflected on the front surface 2 side of the photomask substrate 1, and the flatness of the film surface is insufficient. Therefore, in the third embodiment, before the respective height adjustment mechanisms 20 are driven, the unevenness due to the front side (film surface) 2 side of the mask substrate 1 is measured in the state shown in FIG. 5(b). The height distribution. The height distribution measuring method can be carried out, for example, by a height measuring device which is disposed at a distance from the front surface 2 of the mask substrate 1 corresponding to the main surface of the film surface side by air cushioning or the like. The height measuring device has a mechanism that is vertically above and below the height due to the shape (concavity and convexity) of the front surface 2 of the mask substrate 1, and the mechanism can measure the change in the height of the front surface 2 of the mask substrate 1. However, as a method of measuring the height distribution of the front surface 2 of the mask substrate 1, in addition to the above method, a method of measuring the gas flow rate for maintaining the same member as the height measuring device at a fixed position, or measuring may be used. The method of electrostatic capacitance between the gaps, the method based on pulse counting by laser, the method of optical focusing, and the like are not particularly limited to any method. As the measurement point for the height measurement, it is preferable to use measurement points which are regularly arranged at a fixed interval. For example, a grid point with a pitch of 10 mm can be set as a measurement point. According to this measurement, it is possible to obtain the height of the unevenness which occurs on the front surface 2 side due to the unevenness of the back surface 3 or the inclusion of the foreign matter 16 when the substrate substrate 1 is held by the substrate holding device 10 as shown in Fig. 5(b). Distribution. Next, using the above-described height profile, the height adjustment amount of each support member 12 is determined so that the deviation of the height of the substrate film surface disappears. Then, the height adjusting mechanism 20 of each of the holders 12 is driven in accordance with the height adjustment amount. At the time of driving, for example, when the height adjusting mechanism 20 uses the air damper 21 (FIG. 4), the relationship between the flow rate of the air flowing into the air damper 21 and the rising size of the contact portion 14 is determined in advance. Moreover, when a height adjustment mechanism using a repulsive force based on a magnetic force is employed, the correlation between the amount of current flowing to the electromagnet (not shown) and the rising dimension of the contact portion 14 is obtained in advance. Then, after the height adjustment amount is determined based on the height profile, the flow rate of the air flowing into the air damper 21 or the amount of current flowing to the electromagnet is controlled in order to raise the position of the contact portion 14 in accordance with the height adjustment amount. However, in addition to this, for example, a sensor for detecting the amount of rise of the detecting lever 22 may be used to detect the position (height) of the contact portion 14 that is moved upward by the driving of the height adjusting mechanism 20, based on the detection result. The amount of air flowing into the air damper 21 or the amount of current flowing to the electromagnet is controlled. When the substrate holding device 10 having the above-described configuration is used to hold the mask substrate 1, the height distribution of the front surface 2 of the mask substrate 1 as the film surface is measured in a state in which the photomask is placed, and based on the measurement. As a result, the determined height adjustment amount drives the height adjustment mechanism 20 of each of the support members 12. In other words, in the measurement result of the height distribution, the height adjustment mechanism 20 is driven to lower the contact portion 14 in a portion corresponding to the front surface portion 2 that protrudes upward by the influence of the shape of the back surface. The height adjustment mechanism 20 is driven in such a manner that the contact portion 14 is relatively high in the portion of the front surface 2 which is recessed downward. By this means, the unevenness of the back surface 3 side of the mask substrate 1 or the insertion of the foreign matter 16 is reflected on the front surface 2 side, and the front surface 2 can be maintained flat, and the photomask substrate 1 can be horizontally in this state. Keep it. In addition, as a factor which affects the height distribution of the film surface of the mask substrate 1, that is, the front surface 2 side when the mask substrate 1 is placed on the substrate holding device 10, the unevenness of the back surface 3 side or the foreign matter 16 is sandwiched. In addition, for example, if there are some irregularities on the film surface side of the photomask substrate 1, this factor is also included. However, the unevenness on the film surface side of the mask substrate 1 does not disappear when the mask substrate 1 is removed from the substrate holding device 10 (for example, when it is drawn) and is placed in another device (for example, during exposure). Remaining. Therefore, in the case where the deterioration of the coordinate accuracy due to the change in the shape of the film surface at the time of drawing and the exposure is regarded as a problem, the amount due to the unevenness on the film surface side is excluded. Specifically, when there are a plurality of irregularities on the film surface side of the photomask substrate 1 and it is intended to suppress the influence on the coordinate accuracy due to the mask substrate 1, the following aspects may be employed. In other words, the flatness distribution data (the front surface flatness data) of the front surface 2 which is the film surface of the mask substrate 1 is grasped in advance by flatness measurement. Then, the measurement result of the height distribution performed in the state shown in FIG. 5(b) above is corrected by using the front flatness data which is grasped in advance. Specifically, the front flatness data is subtracted from the measurement result of the height distribution. Then, only the amount corresponding to the difference obtained thereby is reflected to the height adjusting mechanism of each of the holders 12. Thereby, the influence of the unevenness on the film surface side can be suppressed. Further, the data of the flatness distribution (front flatness data) of the film surface side of the photomask substrate 1 can be flexed by the self-weight in the photomask substrate 1 as described above. In the state of being affected (for example, in a state where the main surface of the photomask substrate 1 is held vertically), the flatness of the front surface 2, which is the film surface of the mask substrate 1, is measured by a flatness measuring device. Further, instead of subtracting the front flatness data from the measurement result of the height distribution, the above-described back flatness data can be used to obtain an approximate result. That is, the height adjustment amount of each support member 12 is determined using a map of the flatness obtained by the back flatness data. Then, the height adjustment mechanism 20 of each of the support members 12 can be driven in accordance with the height adjustment amount. <Application Example> The present invention is not limited to the substrate holding device, and may be implemented as another device or method. Specific application examples will be described below. (Drawing Device) The present invention can also be realized as a drawing device including the above-described substrate holding device 10. That is, at the time of drawing, the substrate holding device 10 described above is applied as a holding device for holding the mask substrate 1. In this case, the drawing device includes a substrate holding device 10 that holds the mask substrate 1 horizontally, and a drawing device that draws the photoresist film of the mask substrate 1 held by the substrate holding device 10. The depicting device can use either a laser or an electron beam. In the actual drawing step, since the front surface (film surface) 2 of the mask substrate 1 as the mask base is placed on the upper side and the mask substrate 1 is placed on the stage 11, the flatness of the film surface side is determined according to The flatness of the back side 3 or the thickness of the substrate (TTV; total thickness variation) is deteriorated. In this case, when the drawing device is configured by using the substrate holding device 10 described above, it is possible to prevent the flatness of the film surface side from being deteriorated due to the shape of the back surface. Therefore, it is possible to suppress the deterioration of the coordinates at the time of drawing from being deteriorated at the time of transfer. In this case, there is a large meaning in the manufacture of a photomask for manufacturing a display device having a high tendency to be finer and more integrated. (Photomask Inspection Apparatus) Further, the present invention can be realized as a mask inspection apparatus including the above-described substrate holder 10. In other words, the substrate holding device 10 can be applied to the photomask inspection device, and after the transfer pattern is formed on the photomask substrate 1, it is checked whether or not the transfer pattern satisfies a specific standard. As the mask inspection device, a mask coordinate inspection device or the like can be exemplified. (Manufacturing Method of Photomask) The present invention can also be realized as a method of manufacturing a photomask using the substrate holding device 10. In this case, in the manufacturing steps of the photomask, for example, the following steps are employed. (Preparation step) First, a reticle base is prepared. Specifically, at least one optical film or the like is formed on the main surface of the photomask substrate including the transparent material. The optical film comprises (a) a light-shielding film that shields the exposed light, (b) a semi-transmissive film that partially transmits the exposed light, (c) a portion that transmits the exposed light and shifts the phase of the light. The offset film, (d) an anti-reflection film that prevents reflection of the exposed light, and the like. Further, a photoresist film is formed on the main surface of the photomask substrate so as to cover the optical film. Thereby, a reticle substrate in which an optical film and a photoresist film are formed on the main surface of the reticle substrate including the transparent material is obtained. (Holding Step) Then, the substrate holder 10 prepared by the preparation step is held by the substrate holding device 10. At this time, the film surface on which the optical film or the like is formed is directed upward, and the mask substrate is placed on the stage 11, whereby the mask base is horizontally held by the plurality of holders 12. (Drawing and Developing Step) Then, the mask base held in the holding step is subjected to drawing based on the pattern data. Specifically, the photoresist film is drawn using a laser plotter or the like. At this time, the photoresist film was laser-drawn according to the mask material made based on the design of the desired transfer pattern. Then, development of the photoresist film is performed. Thereby, the excess portion of the photoresist film is removed to form a resist pattern. (Patterning Step) Then, patterning of the optical film is performed. Specifically, the resist pattern is used as an etching mask, and the optical film is etched to form a pattern of the optical film. In this step, the optical film is patterned to form a photomask having a pattern for transfer. Furthermore, in the patterning step, the etching of the optical film may be either wet etching or dry etching. In general, a photomask substrate for manufacturing a display device is a large substrate, and its shape or size is also diverse. Therefore, the etching of the optical film is preferably applied by wet etching. (Resist Removal Step) Then, the above-described resist pattern is removed. Specifically, after the resist pattern is removed by resist stripping, the mask is washed. (Inspection Step) Next, the above-described transfer pattern was inspected. In the inspection step, the substrate holding device 10 holds the photomask and checks the coordinate accuracy of the transfer pattern. Further, it is also possible to form a complicated transfer pattern of a multilayer structure by repeating film formation of an optical film, formation of a photoresist film, patterning of an optical film, and peeling of a resist. Further, when foreign matter or defects are found by inspection of the transfer pattern, the step of removing or correcting the foreign matter or the defect can be performed. After the above steps, the reticle film is attached to the main surface of the reticle as needed to complete the article. In the manufacturing step of the photomask described above, the substrate holding device 10 is advantageously used in the drawing step or the inspection step, respectively. However, the present invention is not limited thereto, and the substrate holding device 10 can be used in any step of correcting the defect found in the inspection step or in any other step of observing or processing the mask. Further, in the step of holding the mask base prepared in the preparation step described above by the substrate holding device 10, the mask base on which the optical film and the resist film are formed may be measured as described in the third embodiment. The height distribution of the main surface (film surface) adjusts the shape of the main surface. Specifically, in the holding step described above, the substrate holder 10 holds the mask substrate with its main surface (film surface) as the upper side. Then, in this state, the height distribution of the main surface of the reticle base is measured to obtain height distribution data, and according to the height distribution data, each height adjustment mechanism 20 is driven to adjust the main surface (film surface) of the reticle base. shape. <Simulation result> FIG. 6 is a view showing a simulation result when the substrate holding device of the above-described embodiment is used to satisfy the coordinate accuracy required for the reticle, and (a) shows the maintenance of the reticle substrate assumed during the simulation. State, (b) indicates the conditions and results of the simulation. The substrate samples A to C are transparent rectangular mask substrates made of quartz glass (the two main surfaces are completely flat), and each has a different size (length × width × thickness). When each of the substrate samples A to C is horizontally disposed on the substrate holding device 10, the deflection caused by the weight of the substrate caused by the adjacent support pins is verified by simulation using the finite element method. What kind of flatness change occurs on the film surface side of the substrate. Further, the coordinate equation of the film surface to which the flatness change is caused is calculated by the following equation. Here, the coordinate offset of the measurement point due to the difference in height can be calculated by using the vector method. Fig. 7 is a diagram showing the coordinate deviation 30 of the measurement point due to the difference in height in the front surface 29 of the substrate in a vector. In FIG. 7, the smaller circle represents the measurement point 31, the dotted line of the triangle represents the inclined surface 32, and the arrows other than the coordinate offset 30 in the inclined surface 32 represent the inclination vector 33, respectively. Among them, the inclined surface 32 is assumed to be an inclined surface made from any three measurement points 31 in the distribution of the height of the substrate front surface 30. In this case, when the lateral direction of the substrate is the X direction, the longitudinal direction of the substrate is set to the Y direction, the height (thickness) direction of the substrate is set to the Z direction, and the offset between the inclined surface 32 and the X-axis direction is ΔX. When the deviation between the inclined surface 32 and the Y-axis direction is ΔY, ΔX is represented by the following formula (1), and ΔY is represented by the following formula (2). ΔX=t/2×cos θx (1) ΔY=t/2×cos θy (2) Here, as shown in FIG. 7 , two tilt vectors 33 can be created from any three measurement points 31 . The normal vector 34 with respect to the inclined surface 32 is calculated based on the outer product of the two tilt vectors 33. Further, cos θx is calculated based on the inner product of the normal vector 34 and the X-axis unit vector 35, and cos θy is calculated from the inner product of the normal vector 34 and the Y-axis unit vector (not shown). By substituting the cos θx and cos θy calculated in this way into the above equations (1) and (2), respectively, the offset ΔY in the X-axis direction and the shift ΔY in the Y-axis direction can be finally calculated. Further, in the above formulas (1) and (2), "t" is the thickness of the substrate (mask substrate). The thickness t of the substrate at each measurement point 31 is included in the thickness distribution data (TTV) of the substrate. However, the thickness t of the substrate may not use the value of the TTV, but the average value of the thickness of the substrate. In the simulation, the substrate sample A having a size of 800 mm × 920 mm × 10 mm in the substrate samples A to C was supported by a total of 72 support pins including an arrangement of 8 × 9 The substrate sample B of the size of 850 mm × 1200 mm × 10 mm is supported by a total of 88 support pins including an arrangement of 8 × 11 , and the substrate sample C having a size of 980 mm × 1150 mm × 13 mm is composed of 10 × The total arrangement of 11 is supported by 110 support pins. As a result, the maximum variation in the flatness in the front surface of the substrate due to the substrate support by the support pin was 0.07 μm for the substrate sample A, 0.11 μm for the substrate sample B, and 0.06 μm for the substrate sample C. Further, in the case of supporting the substrate samples A, B, and C, the intervals of the adjacent support pins are set to 115 mm, 120 mm, and 115 mm, respectively, and are all set to 150 mm or less. As a result, the maximum amount of change (the largest coordinate shift amount) of the coordinates in the front surface 29 of the substrate is 0.006 to 0.012 μm. This coordinate offset is greatly reduced as compared with ±0.2 μm required for the coordinate accuracy of the reticle for manufacturing a display device, and can be sufficiently passed even if it is required to be ±0.1 μm as a reference in the future. . As described above, according to the substrate holding device of the present invention (including the first to third embodiments), it is possible to reduce the unevenness of the back surface of the substrate or the foreign matter on the stage caused by the substrate holding device in the prior substrate holding device. Defects in the deterioration of the coordinates of the cover manufacturing or handling. The substrate holding device of the present invention is preferably used for a device for processing a photomask horizontally during the process of manufacturing the photomask or during inspection, and the use thereof is not particularly limited. In particular, when it is used for a drawing device used in a mask manufacturing process or a processing device such as an inspection device for inspecting coordinate accuracy or a defect correction device, the effect can be clearly obtained. The substrate to be used in the present invention is preferably used for a photomask for manufacturing a display device, and preferably has a square having a side of 300 mm or more (for example, 300 to 1500 mm on one side) and a thickness of 5 to 15 mm. Or rectangular. It is to be noted that in such a large-sized substrate, the holding state is different from that of the LSI (Large Scale Integration) manufacturing mask (one side of the main surface is 5 to 6 inches). An exposure apparatus for a device for exposing a photomask of the present invention is known as a FPD (Flat Panel Display) or an LCD (Liquid Crystal Display) (Liquid Crystal Display) (liquid crystal display), and can be mounted in various specifications. Exposure device for size. For example, in such an exposure apparatus, there is a case where the exposure light of the i-ray to the g-ray is double-exposed, and there is a projection exposure type having a specific optical system (NA (numerical aperture) of about 0.08 to 0.15). Proximity exposure type for proximity exposure. The type or use of the photomask to which the photomask substrate of the present invention is applied is not particularly limited. In addition to the so-called binary mask, it can also be widely applied to a multi-step mask having a halftone in addition to the light-shielding portion and the light-transmitting portion, and having a portion that transmits the exposed light and shifts the phase of the light by a specific amount. A photomask for manufacturing a display device having various configurations or uses, such as a phase shift mask of an offset. Further, in the case of forming a etched portion having a certain depth on the main surface of the substrate in order to form a phase shifter or the like, in the case of using the substrate of the present invention, the effect of cleaning efficiency and suppression of foreign matter is also relative to Previous substrates have achieved excellent results. In particular, the photomask of the present invention is effective in a transfer pattern having a pattern including a finer pattern than before. For example, a CD (Critical Dimension) having a thickness of 2 μm or less, particularly 0.5 to 2.0 μm, is particularly advantageous for a pattern width of 0.5 to 1.5 μm. The reason for this is that in such high-precision photomasks, the specifications of the defects are strict, and the size of the foreign matter allowed is extremely small. For example, in a hole pattern having a diameter of the above size, the presence of foreign matter may have a fatal effect on the operation of the element. Therefore, the effect of the present invention in the photomask for such use can be considered to be remarkable. Accordingly, the present invention is preferred for layers comprising contact holes. <Variation and the like> The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications or improvements in a range in which the specific effects obtained by the constituent elements of the invention or a combination thereof can be derived. For example, in each of the above embodiments, a columnar support member (support pin) 12 that is in point contact with the mask substrate 1 is exemplified, but the present invention is not limited thereto, and a support member that is in line contact with the mask substrate 1 may be used. . Specifically, for example, if the front end (upper end) has a convex shape having a side shape of a cylinder or a "fish cake type" (side shape of an elliptical cylinder), it may be provided with the back surface 3 of the mask substrate 1. For line contact with a specific length. In this case, the line contact portions are preferably linear, and the length thereof is not limited. For example, the line contact portions are substantially the same length as one side of the mask substrate 1, and are arranged in parallel. Thereby, the entire mask substrate 1 can be held horizontally. Further, in the above-described FIG. 2(a), the configuration in which all the support members 12 are arranged at equal intervals is exemplified, but it is not necessary to arrange all the support members 12 at equal intervals. However, it is preferable that each of the support members 12 be regularly arranged. This aspect is also the same in the case of using the support having the contact portion of the above-described line contact.

1‧‧‧Photomask substrate
2‧‧‧ positive
3‧‧‧Back
10‧‧‧Substrate holder
11‧‧‧ stage
12‧‧‧Support
14‧‧‧Contacts
15‧‧‧Abutment
16‧‧‧ Foreign objects
20‧‧‧ Height adjustment mechanism
21‧‧‧Air damper
22‧‧‧ pole
23‧‧‧
29‧‧‧The front side of the substrate
30‧‧‧Coordinate offset
31‧‧‧Measurement point
32‧‧‧Sloping surface
33‧‧‧Tilt vector
34‧‧‧ normal vector
35‧‧‧X-axis unit vector
51‧‧‧Substrate
52‧‧‧ positive
53‧‧‧Back
61‧‧‧ stage
62‧‧‧ plane
63‧‧‧ Foreign objects
t‧‧‧Width ΔX‧‧‧X-axis direction offset ΔY‧‧‧Y-axis offset

1 is a view for explaining the configuration of a substrate holding device according to a first embodiment of the present invention, wherein (a) is a side view showing a state of the photomask substrate before holding, and (b) is a state of holding by the substrate holding device. A side view of the state of the reticle substrate. FIG. 2 is a view for explaining a configuration of a substrate holding device according to a first embodiment of the present invention, wherein (a) is a perspective view showing a state in which a mask substrate is held by a substrate holding device, and (b) is a view showing a configuration of a support member. Side view. 3 is a view for explaining the configuration of a substrate holding device according to a second embodiment of the present invention, wherein (a) is a side view showing a state of the photomask substrate before holding, and (b) is a state of holding by the substrate holding device. A side view of the state of the reticle substrate. Fig. 4 is a side view showing the configuration of a support member having a height adjustment mechanism. Fig. 5 is a view for explaining the configuration of a substrate holding device according to a third embodiment of the present invention, wherein (a) is a side view showing a state of the photomask substrate before holding, and (b) is a view showing that the height adjusting mechanism is not driven. (c) is a side view showing a state in which the substrate holding device holds the photomask substrate, and (c) is a side view showing a state in which the photo-adhesive substrate is held by the substrate holding device while the height adjusting mechanism is driven. 6 is a view showing a simulation result of the substrate holding device of the embodiment which is advantageous for the coordinate accuracy of the reticle, and (a) shows a state in which the reticle substrate is held during the simulation, and (b) Indicates the conditions and results of the simulation. Fig. 7 is a diagram showing the coordinate deviation of the measurement points due to the difference in height in the front surface of the substrate in a vector. 8 is a view for explaining a state in which the substrate is held in the prior art, wherein (a) is a side view showing a state of the photomask substrate before holding, and (b) is a state in which the photomask substrate is placed and held on the stage. Side view.

1‧‧‧Photomask substrate

2‧‧‧ positive

3‧‧‧Back

10‧‧‧Substrate holder

11‧‧‧ stage

12‧‧‧Support

14‧‧‧Contacts

16‧‧‧ Foreign objects

Claims (13)

A substrate holding device characterized in that a photomask substrate for manufacturing a display device is horizontally held, and includes: a stage including a low expansion material; and a plurality of support members disposed on the stage And the support member has a contact portion having a convex curved surface at the front end, and the contact portion is substantially in point contact or line contact with the lower surface side main surface of the mask substrate, thereby holding the mask substrate horizontally. The substrate holding device of claim 1, wherein the support member has a spherical contact portion at a front end, and the contact portion is substantially in point contact with the lower surface side main surface of the photomask substrate. The substrate holding device of claim 1 or 2, comprising: a floating mechanism for holding the stage horizontally on the base in a non-contact state. The substrate holding device according to claim 1 or 2, wherein the plurality of support members are arranged on the stage so that the distance between them is 150 mm or less. The substrate holding device of claim 1 or 2, wherein the plurality of support members each have a height adjustment mechanism. The substrate holding device of claim 5, wherein the height adjusting mechanism utilizes a pressure of a gas. The substrate holding device of claim 5, wherein the height adjusting mechanism uses a force based on a magnetic force. The substrate holding device of claim 5, wherein the height adjusting mechanism includes a driving device that adjusts a height position of the contact portion in accordance with a height adjustment amount. A drawing device comprising the substrate holding device of claim 1 or 2. A reticle inspection apparatus comprising the substrate holding device of claim 1 or 2. A photomask manufacturing method comprising the steps of: preparing a photomask substrate formed by forming an optical film and a photoresist film on a main surface of a photomask substrate comprising a transparent material; and the substrate holding device according to claim 1 or 2 And maintaining the photomask substrate; and patterning the photomask substrate based on the pattern data to pattern the optical film. A method for manufacturing a reticle, comprising the steps of: preparing a reticle substrate formed by forming an optical film and a photoresist film on a main surface of a reticle substrate comprising a transparent material; and patterning the reticle substrate based on pattern data, Patterning the optical film to form a photomask having a transfer pattern; and inspecting the transfer pattern; and in the checking step, including the step of holding the substrate as claimed in claim 1 or 2 The device holds the reticle and checks the coordinate accuracy. A method of manufacturing a reticle, comprising the steps of: preparing a reticle substrate formed by forming an optical film and a photoresist film on a main surface of a reticle substrate comprising a transparent material; and maintaining a step of the substrate holding device The photomask substrate is held in such a manner that the main surface is the upper side; and the drawing step is performed by drawing the mask substrate based on the pattern data; the substrate holding device has a stage on which the photomask substrate is placed And a plurality of support members disposed on the stage and each having a height adjustment mechanism; and the maintaining step includes the step of measuring a height distribution of the main surface to obtain a height distribution data, and Based on the height distribution data, the height adjustment mechanism is driven to adjust the shape of the main surface of the mask base.