TWI604268B - Method of manufacturing a photomask, pattern drawing device, method of inspecting a photomask, device for inspecting a photomask and method of manufacturing a display device - Google Patents

Description

Photomask manufacturing method, drawing device, photomask inspection method, photomask inspection device, and display device manufacturing method

The present invention relates to a photomask that can be preferably used in the manufacture of a semiconductor device or a display device (LCD (Liquid Crystal Display), organic EL (Electroluminescence), etc.), and relates to Manufacturing method and device, inspection method and device.

It is desirable to improve the precision of the transfer pattern formed on the photomask, and further, it is desirable to improve the inspection accuracy of the formed transfer pattern.

In the patent document 1 (JP-A-2010-134433), a drawing method and a drawing device capable of improving the coordinates of the coordinates when the mask pattern is transferred onto the transfer target are described. In particular, Patent Document 1 describes a method for obtaining corrected drawing data in order to eliminate the problem that the film surface (pattern forming surface) when the transfer pattern is drawn in the mask manufacturing step is described. The shape is different from that at the time of exposure, and a pattern as designed is not formed on the object to be transferred.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-134433

In the manufacture of a display device, a photomask having a transfer pattern based on the design of the device to be obtained is often used. A liquid crystal display device or an organic EL display device represented by a smart phone or a tablet terminal as a device is required to be bright, saves power, has a fast moving speed, and has a high resolution. Therefore, the new technical problems are manifested by the inventors for the photomask used for the above purposes.

If it is described in detail, in order to clearly represent a fine image, it is necessary to increase the pixel density, and it is currently desired to realize a device having a pixel density exceeding 400 ppi (pixel per inch). Therefore, the design of the transfer pattern of the photomask tends to be finer and higher in density. Further, a large number of electronic devices including a display device are three-dimensionally formed by laminating a plurality of layers in which fine patterns are formed. Therefore, it is important to improve the coordinate accuracy of the plurality of layers and the mutual coordinates. In other words, if the pattern coordinate accuracy of each layer does not satisfy a certain level, problems such as failure to perform appropriate operations may occur in the completed device. Therefore, the allowable range of coordinate offset required for each layer tends to be smaller and smaller.

Further, Patent Document 1 describes that the shape change amount of the shape of the film surface in the drawing step of the mask base and the shape of the film surface during exposure is estimated, and is used based on the estimated amount of shape change. The design depiction data is revised. Patent Document 1 describes a method of forming a film surface on a substrate at the stage of drawing a transfer pattern (the surface on the side where the transparent substrate is formed on the film, and the film on the mask substrate). In the case where the mask is the surface on which the pattern is formed, the portion remaining in the exposure from the ideal plane, which is also left at the time of exposure, is distinguished from the portion which disappears at the time of exposure, and the corrected drawing material is obtained.

When drawing a pattern on the base of the reticle with the photoresist by drawing the device, the reticle The substrate is placed on the table of the drawing device with the film facing up. At this time, as a deformation factor from the ideal plane of the surface shape of the film surface of the reticle base, four deformation factors described below are considered.

(1) insufficient flatness of the workbench; (2) deflection of the substrate due to the inclusion of foreign matter on the workbench; (3) unevenness of the film surface of the photomask; and (4) due to the back surface of the photomask base The deformation of the film surface caused by the unevenness is such that the surface shape of the reticle base in this state is formed by the accumulation of the above four deformation factors. Moreover, the reticle base of this state is depicted.

On the other hand, when the photomask is mounted on the exposure apparatus, it is fixed such that the film surface faces downward and only the peripheral portion of the mask is supported. The transfer target on which the photoresist film is formed (also referred to as a processed object by etching or the like after being transferred) is disposed under the reticle and irradiated from the reticle (from the back side) The light of exposure. In this state, (1) the insufficient flatness of the table among the above four deformation factors, and (2) the deflection of the substrate due to the foreign matter being caught on the table disappears. Further, in this state, (4) the unevenness on the back surface of the substrate remains, but the surface shape of the back surface on which the pattern is not formed does not affect the transfer of the front surface (pattern forming surface). On the other hand, the deformation factor remaining when the photomask is used in the exposure apparatus is the above (3).

That is, the deformation factors of (1), (2), and (4) exist at the time of drawing, and disappear at the time of exposure. This change causes the coordinates of the drawing to be shifted from the exposure. Therefore, as long as the amount of change in the surface shape derived from the deformation factors of the above (1), (2), and (4) from the ideal plane is corrected, the design drawing data is corrected and the data is not drawn. 3) The amount of surface shape change of the deformation factor is reflected in the above correction, and a mask having a more accurate transfer performance of the coordinate design data can be obtained.

Therefore, according to the method of Patent Document 1, the coordinate accuracy of the pattern formed on the transfer target can be improved.

On the other hand, the mask in the exposure apparatus is held and supported by the holding member of the exposure apparatus in the holding area near the periphery of the substrate, whereby the deformation of the substrate is caused by the restriction. Further, in the case of a photomask for manufacturing a display device or the like, since a large-area substrate is supported in the vicinity of the periphery of the substrate, the influence of the deflection due to its own weight cannot be ignored. In this case, the deformation of the film surface also affects the area where the mask is patterned, which may cause deterioration of the coordinate accuracy. The present inventors have found that such a fine influence is also required in consideration of the miniaturization or high integration of the pattern of a high-performance display device or the like currently developed.

For example, a device such as a display device is formed by laminating a patterned film, but each layer of the laminate is formed by a transfer pattern formed by each of the different masks. Of course, the reticle used is manufactured based on strict quality management. However, since the reticle is different, it is difficult to make the flatness of the surface the same as the completely ideal plane, and it is also difficult to make the film surface shape completely coincident with the plurality of reticle.

Therefore, in each of the reticle, the shape of the film surface has an individual difference, and when the film shape is expressed in consideration of the film surface shape when the reticles are held in the exposure device, the correction of the drawing data can be performed to form a coordinate with higher precision. Transfer pattern.

In other words, the present inventors have found that a method for improving the accuracy of the coordinate accuracy caused by the difference in the film surface posture at the time of drawing and exposure can be obtained by the method of Patent Document 1, but it is improved in order to further improve the accuracy. The yield of a device having a plurality of layers is advantageous in that a slight individual difference in the shape of the film surface of the mask substrate used in each layer and the force exerted by the exposure device in the exposure layer are also considered. The deterioration of the transfer property due to the influence is substantially eliminated.

Accordingly, an object of the present invention is to provide a method of manufacturing a photomask capable of improving the coordinate accuracy of a pattern formed on a transfer target, a drawing device, a method for inspecting a photomask, an inspection device for a photomask, and a display device. method.

In order to solve the above problems, the present invention has the following constitution.

(Composition 1)

A method of manufacturing a photomask comprising a photomask substrate prepared with a film and a photoresist film formed on a main surface of a substrate, and drawing a specific transfer pattern by a drawing device, and having: a step of preparing a pattern design material A for designing a transfer pattern; obtaining a transfer surface shape data C indicating a shape of the main surface when the photomask is held by the exposure device; obtaining the upper surface of the main surface a step of height-distributing the data E at the time of drawing the height distribution of the main surface in a state where the reticle substrate is placed on the table of the drawing device; and using the above-described height distribution data E and the transfer surface shape data C: obtaining a step of drawing the difference data F; and estimating a coordinate offset amount corresponding to the drawing difference data F from a plurality of points on the main surface to obtain a coordinate value G for drawing; and using The drawing step of drawing the mask offset data G and the pattern design data A on the mask base is described above.

(constituent 2)

A method of manufacturing a photomask comprising a photomask substrate prepared with a film and a photoresist film formed on a main surface of a substrate, and drawing a specific transfer pattern by a drawing device, and having: a step of preparing a pattern design material A for designing a transfer pattern; a step of preparing a substrate surface shape data B obtained by measuring a surface shape of the main surface; a step of obtaining a transfer surface shape data C by shifting the surface shape based on the shape of the holding member in the surface of the substrate when the photomask is held in the exposure device, so that the main surface is a step of measuring the height distribution of the main surface while the photomask substrate is placed on the table of the drawing device on the upper side, and obtaining the height distribution data E at the time of drawing; using the height distribution data E and a step of drawing the difference data F by the transfer surface shape data C, and estimating the coordinate offset of the plurality of points on the main surface corresponding to the drawing difference data F to obtain the coordinate value G for drawing And a drawing step of drawing on the mask base using the coordinate offset data G and the pattern design data A described above.

(constitution 3)

In the method of manufacturing the photomask of the second aspect, the finite element method is used in the step of obtaining the transfer surface shape data C.

(construction 4)

The method of manufacturing a reticle according to any one of the above 1 to 3, wherein, in the drawing step, the correction pattern data obtained by correcting the pattern design material A based on the coordinate offset amount data G for the drawing is used. H is depicted.

(Constituent 5)

The method of manufacturing a photomask according to any one of the first to third aspect, wherein in the drawing step, the coordinate system of the drawing device is corrected based on the drawing coordinate offset amount G, and the obtained coordinate system is obtained. The coordinate system and the above-mentioned pattern design data A are corrected and depicted.

(constituent 6)

A method of manufacturing a reticle according to any one of 1 to 5, wherein the reticle is maintained When in the exposure apparatus, a plurality of holding points held by the holding member are disposed on the plane.

(constituent 7)

The method of manufacturing a reticle according to any one of 2 to 6, wherein the substrate surface shape data B is obtained by holding the reticle substrate in a manner that the main surface is vertical or for forming the reticle substrate. In the state of the substrate, the position of the plurality of measurement points on the main surface is measured and determined.

(Composition 8)

A drawing device for drawing a pattern for transfer on a mask base on which a film and a photoresist film are formed on a main surface of a substrate, and having a height measuring mechanism that causes the main surface to be upper side The mask base is placed on the table, and the height distribution of the main surface is measured to obtain the height distribution data E at the time of drawing; the input mechanism inputs the pattern design data A of the transfer pattern, and the representation The transfer surface shape data C of the main surface shape of the substrate in which the substrate is held in the exposure apparatus; the calculation means calculates the plural number on the main surface using the height distribution data E and the transfer surface shape data C A coordinate offset map data G is drawn; and a drawing means is formed on the mask base using the above-described drawing coordinate offset data G and the pattern design data A.

(constituent 9)

A drawing device for drawing a pattern for transfer on a mask base on which a film and a photoresist film are formed on a main surface of a substrate, and having a height measuring mechanism that causes the main surface to be upper side The reticle substrate is placed on the table, and the height distribution of the main surface is measured to obtain the height distribution data E at the time of drawing; An input mechanism that inputs pattern design data A of the transfer pattern, a substrate surface shape data B indicating a shape of a main surface of the substrate, information related to a holding state when the substrate is held in an exposure device, and the above a substrate physical property information of a physical property value of the substrate material; and an arithmetic unit that calculates the main surface of the substrate in a state of being held in the exposure device using the substrate surface shape data B, information related to the holding state, and the substrate physical property information a transfer surface shape data C of a surface shape, and a coordinate value G for drawing a plurality of points on the main surface on the main surface using the height distribution data E and the transfer surface shape data C described above; and a drawing mechanism Drawing is performed on the mask base using the above-described drawing coordinate offset data G and the pattern design data A.

(construction 10)

A method for inspecting a photomask, wherein an inspection device is used to inspect a photomask having a transfer pattern in which a thin film is patterned on a main surface of a substrate, and the photomask is placed on the inspection a step of obtaining a pattern coordinate data L by measuring a coordinate of the transfer pattern formed on the main surface in a state on a table of the apparatus; obtaining a shape of the main surface when the mask is held by the exposure apparatus a step of transferring the surface shape data C; measuring the height distribution of the main surface to obtain a height distribution during inspection by placing the photomask on the upper surface of the inspection apparatus while the main surface is on the upper side a step of the data I; obtaining the step of examining the difference data J by using the height distribution data I and the transfer surface shape data C; and estimating a coordinate offset of the plurality of points on the main surface corresponding to the inspection difference data J The step of determining the coordinate offset data K for inspection; and The step of inspecting the transfer pattern is performed using the above-described inspection coordinate offset data K and the pattern coordinate data L.

(Structure 11)

A method for inspecting a photomask, wherein an inspection device is used to inspect a photomask having a transfer pattern in which a thin film is patterned on a main surface of a substrate, and the photomask is placed on the inspection a step of obtaining a pattern coordinate data L by measuring a coordinate of the transfer pattern formed on the main surface in a state on a table of the apparatus; preparing a surface shape data of the substrate obtained by measuring a surface shape of the main surface a step of obtaining a transfer surface shape data C by shifting the surface shape based on the shape of the holding member while the reticle is held in the exposure device; a step of measuring the height distribution of the main surface and obtaining the height distribution data I during the inspection in a state where the main surface is the upper side and the photomask is placed on the table of the inspection apparatus; and the height distribution is used when the inspection is performed. The data I and the transfer surface shape data C are obtained by the step of checking the difference data J; the estimation is based on the above-mentioned inspection difference data J The step of determining the coordinate value K for inspection using the coordinate offset of the plurality of points on the main surface; and performing the transfer pattern using the coordinate value K for inspection and the pattern coordinate data L The steps of the inspection.

(construction 12)

In the inspection method of the photomask of the eleventh aspect, in the step of obtaining the transfer surface shape data C, the finite element method is used.

(construction 13)

The method of inspecting a photomask according to any one of 10 to 12, wherein in the step of performing the inspection of the transfer pattern, the coordinate value K for inspection is reflected in the pattern design data A. The design data M and the pattern coordinate data L are corrected to perform the inspection of the transfer pattern.

(construction 14)

The method of inspecting a photomask according to any one of 10 to 12, wherein in the step of performing the inspection of the transfer pattern, the coordinate value K for inspection is reflected in the pattern coordinate data L. The coordinate data N and the pattern design data A are corrected to perform the inspection of the transfer pattern.

(construction 15)

A method of manufacturing a reticle, comprising: a step of preparing a reticle substrate on which a film and a photoresist film are formed on a main surface; a step of patterning the film; and utilizing any one of the compositions 10 to 14 The inspection procedure of the inspection method of the reticle.

(construction 16)

A manufacturing method of a display device, comprising: a step of preparing a photomask manufactured by the method for manufacturing a photomask according to any one of 1 to 7 and having a transfer pattern formed on a main surface; and The step of patterning the device substrate having the processed layer by exposing the mask.

(Construction 17)

A method of manufacturing a display device, comprising: pattern-transferring a plurality of processed layers formed on a device substrate by using a plurality of masks and exposure devices formed on respective main surfaces with a transfer pattern; Further, the photomask is manufactured by the method of manufacturing the photomask according to any one of the configurations 1 to 7 as the plurality of masks.

(Composition 18)

An inspection apparatus for a photomask that inspects a photomask having a transfer pattern in which a thin film is patterned on a main surface of a substrate, and has a coordinate measuring mechanism that performs the above-described main surface The coordinates of the transfer pattern are measured to obtain the pattern coordinate data L. The height measuring mechanism measures the height distribution of the main surface in a state where the main surface is placed on the table while the main surface is on the upper side. And a height distribution data I at the time of inspection; an input mechanism that inputs a transfer surface shape data C indicating a shape of a main surface of the substrate in a state in which the substrate is held in an exposure device; and an arithmetic unit that uses the height distribution data I at the time of the inspection And the transfer surface shape data C to calculate a plurality of inspection coordinate offset data K on the main surface; and an inspection mechanism that uses the inspection coordinate offset data K and the pattern design data A to The transfer pattern of the photomask is inspected.

(Composition 19)

An inspection apparatus for a photomask that inspects a photomask having a transfer pattern in which a thin film is patterned on a main surface of a substrate, and has a coordinate measuring mechanism that performs the above-described main surface The coordinates of the transfer pattern are measured to obtain the pattern coordinate data L. The height measuring mechanism measures the height distribution of the main surface in a state where the main surface is placed on the table while the main surface is on the upper side. And obtaining an inspection height distribution data I; an input mechanism that inputs a substrate surface shape data B indicating a shape of a main surface of the substrate, information related to a holding state when the substrate is held in the exposure device, and a substrate physical property information including a physical property value of the substrate material; and an arithmetic unit that calculates the substrate held in the exposure device using the substrate surface shape data B, information related to the holding state, and the substrate physical property information The transfer surface shape data C of the main surface shape, and the inspection coordinate offset data K of the plurality of points on the main surface is calculated using the inspection height distribution data I and the transfer surface shape data C; and the inspection mechanism The inspection pattern of the photomask is inspected using the inspection coordinate offset data K and the pattern design data A.

According to the present invention, it is possible to provide a method of manufacturing a photomask capable of improving the coordinate accuracy of a pattern formed on a transfer target, a drawing device, a method of inspecting a photomask, an inspection device for a photomask, and a method of manufacturing the display device.

10‧‧‧Workbench

11‧‧‧ depicting institutions

12‧‧‧Measurement agency

13‧‧‧Photomask base (substrate)

14‧‧‧ Film

15‧‧‧ depicting data production agencies

20‧‧‧ surface

21‧‧‧ reference surface

D‧‧‧Offset

H‧‧‧ Height

T‧‧‧thickness

X‧‧‧ direction

Y‧‧‧ direction

Z‧‧‧ direction

Φ‧‧‧ angle

ΔX‧‧‧X-axis offset

ΔY‧‧‧Y-axis offset

Fig. 1(a) is a side view of the substrate held in such a manner that the main surface is parallel to the vertical direction, and Fig. 1(b) is a front view of the substrate.

Fig. 2(a) is a cross-sectional view of a substrate on which a plurality of measurement points are set, and Fig. 2(b) is a front view of the substrate.

Fig. 3(a) is a cross-sectional view of a reticle model used in the finite element method, and Fig. 3(b) is a front view of the reticle model.

4(a) is a cross-sectional view of a mask model in which the film surface is on the upper side, and FIG. 4(b) is a cross-sectional view of the mask model in which the film surface is on the lower side, and FIG. 4(c) is a cross-sectional view of FIG. The front view of the mask model in which the film surface is disposed on the upper side, and FIG. 4(d) is a front view of the mask model in which the film surface is disposed on the lower side.

Fig. 5(a) is a cross-sectional view of the reticle model in the holding position of the holding member. Fig. 5(b) is a front view of the reticle model, and the holding position by the holding member is indicated by a broken line.

Figure 6(a) is a cross-sectional view showing an example of a force applied to a photomask held by an exposure device. Figure. Fig. 6(b) is a view showing an example of a region where a vacuum pressure is applied to the mask and a holding position of the holding member.

Fig. 7 is a schematic view showing a hexahedron constituting a mask model.

8(a) to 8(e) show the difference data F obtained by obtaining the difference between the height distribution data E and the transfer surface shape data C after the transfer surface shape data C is obtained from the substrate surface shape data B, and then A schematic diagram of the steps of drawing the coordinate offset data G from the drawing difference data F.

Fig. 9 is a schematic view for calculating the relationship between the shape change of the film surface and the coordinate shift caused thereby.

10(a) to (e) show that the inspection difference data J is obtained by the difference between the height distribution data I and the transfer surface shape data C at the inspection, and the inspection coordinate offset data K is obtained from the inspection difference data J. The pattern diagram of the steps up to that.

Fig. 11 is a conceptual diagram of a drawing device used in a method of manufacturing a photomask according to an embodiment.

Fig. 12 (a) and (c) show the coordinate measurement results of the pattern drawn on the test reticle. 12(b) and 12(d) show the results of simulating the coordinate shift in the state in which the test reticle is placed on the exposure device.

Fig. 13 is a graph showing the coordinate shift of the measurement point due to the difference in height in a vector.

<Embodiment 1>

A method of manufacturing a photomask according to an embodiment of the present invention has the following steps.

Prepare the reticle base

In an embodiment of the present invention, a transfer pattern designed based on a device to be obtained is formed on a mask substrate on which a plurality of thin films and a photoresist film are formed on a main surface of a substrate to form a transfer pattern. The depiction of the mask. Therefore, it is prepared on the main surface of one of the substrates A reticle substrate having the above film and photoresist film.

A well-known person can be used for the prepared reticle substrate.

As the substrate, a transparent substrate such as quartz glass can be used. The size and thickness are not limited, but those which can be used in the manufacture of a display device can be used with a side of 300 mm to 1800 mm and a thickness of 5 to 15 mm.

In the present specification, there is a case where, in addition to the substrate before the formation of the film, a substrate on which one or a plurality of films before or after patterning is formed on the main surface, or a substrate on which a photoresist film is formed on the film is referred to as "Substrate" (or mask base substrate, mask substrate).

In the step of measuring the flatness or height distribution of the main surface of the substrate, the influence of the thickness of the film or the photoresist film formed on the main surface is not substantially generated. The reason for this is that the film thickness of the film or the photoresist film is sufficiently small to have no substantial influence on the above measurement.

As the film, in addition to the light-shielding film (optical density OD=3 or more) that shields the exposed light when the mask is used, it may be a semi-transmissive film that transmits a part of the exposed light (the light transmittance of the exposure is 2 to 80%). ), or may be a phase shift film (for example, a phase shift of the exposed light is 150 to 210 degrees, an exposure light transmittance of about 2 to 30%) or an anti-reflection control of light. An optical film such as a reflective film. Further, the film may include a functional film such as an etching stopper film. It can be a single film or a laminate of a plurality of films. For example, a light-shielding film or an anti-reflection film containing Cr, a semi-transmissive film containing a Cr compound or a metal telluride, a phase shift film, or the like can be applied. A reticle substrate in which a plurality of films are laminated may also be applied. By applying the method of the present invention to the patterning of each of the plurality of films, a transfer mask having excellent coordinate accuracy can be produced.

The photoresist formed on the outermost surface may be either positive or negative. As a mask for a display device, a positive type is useful.

I Steps to prepare pattern design data A

The pattern design data is information on a transfer pattern designed based on a device (display device or the like) to be obtained.

The use of the device manufactured by the photomask of the present invention is not limited. For example, an excellent effect can be obtained by applying the present invention to each layer constituting each constituent of a liquid crystal display device or an organic EL display device. For example, the present invention can be preferably used for a line and gap pattern having a pitch of less than 7 μm (a portion having a line or gap line width (CD: Critical Dimension) of 4 μm or less than 3 μm, etc.) or a diameter A photomask or the like for a display device having a fine design such as a hole pattern of 1.5 to 5 μm, particularly 1.5 to 3.5 μm.

The pattern design data is directly used for drawing without correction, and the transfer is caused by the difference in film shape between the drawing (when placed in the drawing device) and during exposure (when held in the exposure device). The coordinate accuracy when the pattern is formed on the object to be transferred becomes insufficient. Therefore, the correction by the following steps is performed.

II Steps to obtain the transfer surface shape data C

The transfer surface shape data C indicating the amount of deformation of the film surface generated when the photomask is held and supported by the exposure device is obtained. Specifically, it can be carried out as follows.

II-1 Steps of Obtaining Surface Shape Data of Substrate B

The substrate surface shape data B is obtained by measuring the flatness of the main surface (film side).

For example, it can be measured by a flatness measuring machine in such a manner that the substrate to be measured is held such that the main surface is substantially vertical, and the deflection due to its own weight does not substantially affect the shape of the main surface ( Refer to Figure 1).

The measurement can be performed by a flatness measuring machine using an optical measuring method such as detecting the reflected light of the irradiated light (such as a laser). Examples of the measuring device include, for example, a flatness measuring machine FTT series manufactured by Kuroda Seiko Co., Ltd., or a Japanese Patent Publication No. 2007-46946.

At this time, the plural number is set on the main surface at equal intervals (the distance is set to the pitch P). The intersection point (checker point) of the squares drawn along the XY direction can be used as the measurement point (see Fig. 2).

For example, a flatness measuring machine having a function in which a substantially vertical plane is a reference plane and a distance between the reference plane and the Z direction (see FIG. 2) of each of the measurement points described above can be used. By this measurement, the flatness of the main surface of the substrate can be grasped, whereby the substrate surface shape data B can be obtained. An example in which the pitch P is set to 10 mm is shown in FIG.

As shown in Fig. 2(a), the height in the Z direction of all the measurement points on the main surface was measured. Thereby, the substrate surface shape data B is obtained in the form of a flatness map (see FIG. 8(a)).

Further, when the substrate surface shape data B is obtained, the measurement is performed at the position corresponding to the film surface side on the back surface side of the substrate (the surface opposite to the main surface on which the film surface is formed), thereby performing the same measurement. The back surface shape data of the substrate and the thickness (distance between the film surface and the back surface) of the substrate at each measurement point can be obtained in advance. The thickness distribution of the substrate is also described as TTV (Total thickness variation). This information can be used in the latter paragraph.

For the setting of the measurement point, the distance P can be determined from the viewpoint of the measurement time of the size of the substrate and the viewpoint of the correction accuracy. The distance P may be, for example, 2 ≦ P ≦ 20 (mm), and more preferably 5 ≦ P ≦ 15 (mm).

Further, after the surface flatness measurement on the film surface side is performed, the least square plane can be obtained from the measured values. Set the center of the face to the origin O.

II-2 Steps to obtain the transfer surface shape data C

Next, when the substrate is a photomask, it is considered that the photomask is held in the exposure apparatus. The photomask provided in the exposure device is held in a state in which the film surface faces the lower side. In this state, the film surface (transfer surface) of the substrate receives different forces depending on the holding state, and the shape thereof changes. For example, the force applied to the reticle varies depending on the shape of the holding member. Furthermore, in order to counter the self-weight of the reticle and reduce the deflection of the transfer surface of the reticle, The back surface of the cover (the surface opposite to the film surface side) is set to a specific region when a force due to vacuum pressure is applied to the region (Fig. 6(b)), depending on the region or the magnitude of the vacuum pressure. The force exerted by the reticle changes. Here, the case where the vacuum pressure is applied refers to a state in which the reticle is sucked upward by decompressing the space on the back surface of the mask transfer surface.

The surface shape (transfer surface shape) of the substrate in a state in which such a force is applied can be measured. That is, a desired number of measurement points are provided on the film surface of the photomask provided in the exposure machine, and the surface shape of the measurement point is measured by an optical mechanism or the like, whereby, for example, as shown in FIG. 10(b), The mapping table shown.

However, the present invention can be carried out without measuring the shape of the transfer surface described above. For example, it is possible to estimate the displacement generated by the mask film surface held in the state of the exposure apparatus, and to reflect the shift on the substrate surface shape data B to obtain the transfer surface shape data C (see FIG. 8(b)). That is, it is possible to use information relating to the holding state which affects the shape of the main plane when the reticle is held in the exposure apparatus, which includes the holding condition by the holding member and the vacuum pressure condition against the self-weight, by simulation The transfer surface shape data C.

In this step, it is preferred to apply the finite element method. Therefore, a mask model is produced as a preparation stage (Fig. 3).

The surface shape information of the substrates of the two surfaces was obtained by measuring the flatness of the film side and the back side. Here, one virtual measurement point is added to the substrate end side at a position spaced apart by one interval from the measurement point of the outermost circumference, and the height of the virtual measurement point in the Z direction is set to be the outermost circumference. Point the same height. This treatment is used to accurately reflect the size and weight of the substrate in the finite element method used below. Further, a virtual measurement point is set in the middle of the measurement points corresponding to the film surface side and the back surface side, and the median value of the corresponding two measurement values is set. Further, the adjacent measurement points (including the virtual measurement points) are connected by a straight line (see FIGS. 3(a) and 3(b)).

In addition, the virtual measurement point is not limited to the case where it is provided in the center of the measured value of the film surface and the back surface, and two points or three points may be provided at equal intervals in the thickness direction.

4(a) to 4(d) are schematic views showing the mask model viewed from the front and back surfaces and the cross section.

Next, in the reticle model, the reticle is set to be held in the exposure device at a plurality of holding points of the holding member. The plurality of holding points are held and restricted by the holding member when the photomask is mounted in the exposure device, and are different depending on the manufacturer, generation or size of the exposure device, so that the exposure is based on the exposure. Determined by the device.

In the present embodiment, as an example, a case of a quadrangular strip-shaped holding member disposed at a predetermined distance from the outer circumference in parallel with the four sides in the vicinity of the four sides of the outer surface of the main surface of the substrate is described. The film surface side of the substrate is brought into contact with the pattern forming region for transfer (dashed line in FIG. 5(b)).

That is, in the model shown in FIGS. 6(a) and 6(b), the measurement point on the broken line is set as the holding point. In the exposure apparatus, the holding point is restricted and displaced by contact with the holding member, whereby the displacement of the substrate is affected by the physical properties of the substrate.

Further, as described above, since the self-weight is applied to the substrate to cause deflection, the force for lowering the deflection is given. This is performed by applying a vacuum pressure from above (back side) of the substrate (Fig. 6(a)). As shown in Fig. 6(b), the region where the vacuum pressure is applied may be a quadrangular region including the center of the main surface of the substrate.

In the model shown in FIG. 5( a ), the forced shift amount is set such that the position of the measurement point which is the holding point becomes zero on the Z axis. Furthermore, the zero position in the Z-axis direction refers to the least square plane (and the origin above the least square plane) that has been set. For example, when the value of the flatness of the film surface side at a certain measurement point of the holding point is 5 μm, the forced shift amount of the measurement point is "-5 μm".

Further, the amount of vacuum pressure applied from the back side of the substrate is set to be the smallest amount of flatness of the film surface.

Furthermore, there are situations in which the flatness of a particular face is evaluated. In the case of the distance between the surface and the reference surface (the surface which is substantially parallel to the specific surface is a reference plane), the difference between the maximum value and the minimum value of the distance is expressed. That is, when the value of the flatness is small, it means that the surface has less unevenness and is flatter.

Therefore, in order to determine the amount of vacuum pressure applied to the simulation, it is sufficient to determine the vacuum pressure when the flatness of the film surface is minimized when the vacuum pressure applied to the back surface of the mask substrate is changed. Generally, the displacement due to the self-weight deflection of the substrate is maximized near the center of the substrate, so that the distance from the center point of the film surface (the main surface of the substrate) to the reference surface is considered to be the closest to the outer edge of the substrate. The flatness is the smallest at the distance. When measuring the distance from the outer edge of the substrate to the reference surface, a plurality of measurement points may be set on the outer edge, or a specific position may be set as a representative point. Further, the vacuum pressure at which the film surface flatness is minimized can be actually measured by actually mounting the substrate on the exposure device, or can be obtained as one of simulations using information related to the above-described holding state.

Next, the above-described model conditions are input to the software of the finite element method (FEM), and the above-described forced shift is used to estimate which shift is performed for each measurement point except the holding point. Thereby, the "transfer surface shape data C" indicating the film surface shape of the photomask in the exposure apparatus can be obtained.

When applying the finite element method, various physical property values or conditions are required. In the present embodiment, the following are exemplified.

[Substrate (quartz glass) physical property value conditions]

Young's modulus E: 7341kg/mm ²

Poisson's ratio ν: 0.17

Weight density m: 0.0000022kg/mm ³

[Mask Model Conditions]

Coordinate values (x, y, z) of each measurement point: (all measurement points on the film side, back side, intermediate point)

Condition file linking test points: hexahedron

In the present embodiment, the measurement points corresponding to the film surface and the back surface, and the intermediate points (including the virtual measurement points) are connected to each other to form a hexahedral integrated model (see FIG. 7).

[keep condition]

Set the file of the forced shift amount: the forced shift amount of the above hold point

[Vacuum pressure condition]

A file in which an amount of vacuum pressure is applied and an area where the amount of the vacuum pressure is applied is set

Further, the amount of shift of all the measurement points except the holding point is calculated by the finite element method.

The reticle held in the exposure apparatus is stationary by the balance of the forces acting on it. At this time, the self-weight vector G-stress vector σ-vacuum pressure vector=0

Established.

Here, the stress vector σ = [k] × shift amount vector u

(where [k] is a matrix composed of Young's modulus e and Poisson's ratio v)

Self-weight vector G = element volume × weight density m × gravity direction vector.

Here, as shown in FIG. 7, each element is a respective hexahedron.

If the hexahedron is overlapped for all elements (the entire substrate), then G1-σ1-F1+G2-σ2-F2+G3-σ3-F3+...=0

G1-F1+G2-F2+G3-F3+...=σ1+σ2+σ3+...=[k1]u1+[k2]u2+[k3]u3+...

Here, the shift amount vectors (u1, u2, u3, ...) are the shift amounts of the respective measurement points, and are the values to be obtained. However, the shift amount vector of the hold point is input as the forced shift amount as described above.

Obtaining the shift amount vector of each measurement point calculated by the above finite element method The data of the film surface shape of the reticle held in the exposure device. That is, the data is the material of the film surface shape of the mask at the time of pattern transfer by the exposure device, and is "transfer surface shape data C".

III. Steps to obtain a highly distributed data E when depicting

Fig. 11 is a conceptual diagram of a drawing device used in a method of manufacturing a reticle according to an embodiment of the present invention. The drawing device includes at least a table 10, a drawing unit 11, a height measuring unit 12, and a drawing material creating unit (computing unit) 15. On the table 10, a mask base 13 is fixed. The mask base 13 is formed with a film 14 formed on one surface so that the surface on which the film 14 is formed faces upward. The drawing means 11 is, for example, for irradiating an energy beam such as a laser, and in the drawing step, a specific transfer pattern is drawn on the mask substrate 13 with the photoresist film attached to the table 10. The height measuring mechanism 12 is disposed in such a manner as to be spaced apart from the surface of the mask base 13 by a cushion or the like. The height measuring mechanism 12 is a mechanism that moves up and down according to the change in height due to the surface shape of the mask base 13, and can measure the height (Z direction) of the main surface of the mask base 13.

Further, as a method of measuring the height of the surface, in addition to the above method, the following methods may be used without limitation. The air flow rate for maintaining the same member as the height measuring mechanism 12 at a fixed position is used. Method of measurement; method of measuring electrostatic capacitance between gaps; counting using laser pulses; using optical focus.

The main surface (membrane surface side) was placed on the upper side, and the photomask substrate was placed on a table of such a drawing device, and the height of the film surface of the set measurement point (separated distance P) was measured. The one obtained by mapping the measurement is the height distribution data E at the time of drawing shown in FIG. 8(c).

As described above, it can be considered that the deformation factor from the ideal plane of the height distribution is obtained by accumulating the following four deformation factors.

(1) the unevenness of the work surface, (2) the deflection of the substrate due to the inclusion of foreign matter on the table; (3) the unevenness of the film surface of the mask base, and (4) Concavity and convexity of the film surface due to the unevenness of the back surface of the photomask base

Further, the film surface of the mask base in this state is drawn.

IV Get the steps to describe the differential data F

Next, the drawing difference data F is obtained using the obtained drawing height distribution data E and the previously obtained transfer surface shape data C. In the present aspect, the difference between the height distribution data E at the time of drawing and the transfer surface shape data C is obtained. This difference is the difference between the film surface shape of the mask base at the time of drawing and the film surface shape of the mask at the time of exposure. This difference is a drawing difference data F (refer to FIG. 8(d)).

The deformation factor from the ideal plane of the film surface of the photomask held in the exposure apparatus is obtained by accumulating the three deformation factors described below.

(5) the unevenness of the film surface of the photomask (substantially the same as (3) above), (6) the deformation of the film surface forcibly generated by the holding of the mask holding member, and (7) the self-weight Deflection, and deformation in the opposite direction due to the vacuum pressure used to reduce the deflection

Therefore, the difference between the two film surface shapes is a factor that causes the coordinate shift due to the transfer, and therefore it should be applied to the corrector of the "pattern design data A". That is, the difference is the above-described drawing difference data F.

V Steps to draw the coordinate offset data G

The above-described drawing difference data F is converted into a shift (coordinate offset) on the XY coordinates. For example, the conversion can be performed by the following method (refer to FIG. 9).

Fig. 9 is an enlarged view showing a cross section of a substrate (mask base) 13 on the stage 10 of the apparatus. The film 14 is omitted. As described above, the shape of the surface 20 of the substrate 13 disposed on the table 10 is deformed from an ideal plane due to a plurality of factors.

In the height-distribution data E at the time of drawing, when the height of the measurement point adjacent to the measurement point of the height 0 (that is, the measurement point whose height coincides with the reference surface 21) is H, the substrate due to the difference in height The angle Φ between the surface 20 of the 13 and the reference surface 21 is such as The following formula indicates: sinΦ=H/Pitch...... (Formula 1)

(Pitch: The distance between the measurement points, that is, the distance P from the adjacent measurement point).

Furthermore, in the above, H/Pitch can also be considered as a gradient in the height direction of the substrate surface.

Furthermore, if the value of Φ is sufficiently small, it can also be approximated by: Φ = H / Pitch (Expression 1').

In the following description, (Formula 1) is used.

In the above case, the offset d of the X-axis direction of the measurement point due to the difference in height can be obtained by the following equation: d = sin Φ × t / 2 = H × (t / 2 Pitch). .. (Formula 2).

Further, in the above, if Φ is sufficiently small, it may be approximated by: d = Φ × t / 2 = H × (t / 2 Pitch) (Expression 2').

Alternatively, the coordinate offset of the measurement point due to the difference in height can also be calculated by using a vector method. Fig. 13 is a graph showing the coordinate shift of the measurement point due to the difference in height in a vector. In the height-distribution data E at the time of drawing, the inclined surface prepared from the measurement points of any three parts is considered. At this time, the offset ΔX between the inclined surface and the X-axis direction and the offset ΔY between the inclined surface and the Y-axis direction are expressed by the following expression.

ΔX=t/2×cosθx

ΔY=t/2×cos θy (Expression 3)

Two tilt vectors can be created from the measurement points of any three parts. A normal vector with respect to the inclined surface is created based on the two oblique vector outer product calculations.

Further, cos θx is calculated from the inner product of the normal vector and the X-axis unit vector, and cos θy is calculated from the inner product of the normal vector and the Y-axis unit vector.

The calculated cos θx and cos θy can be substituted into (Formula 3) to finally calculate the deviation in the X-axis direction. Shift the offset ΔY in the ΔX and Y-axis directions.

Furthermore, t here is the thickness of the substrate. The thickness t of each measurement point is included in the TTV which has been obtained in the above. Furthermore, the average value of the thickness of the substrate may be used here without using the value of the TTV.

Therefore, in the present embodiment, the height corresponding to the difference between the transfer surface shape data C and the drawing height distribution data E is obtained for all the measurement points on the substrate 13, and the obtained difference data F is obtained in the X direction and the Y direction. The coordinate offset is calculated, whereby the coordinate value G for drawing is obtained. Of course, the calculation method is not limited to the above as long as the effects of the present invention are not impaired.

VI Performing the drawing steps of the correction pattern data H

Using the above-described drawing coordinate offset data G and "pattern design data A", the correction pattern data H is drawn on the mask base.

At this time, the pattern design data A can be corrected based on the drawing coordinate offset data G to obtain the drawing correction pattern data H (not shown), and the drawing correction pattern data H can be drawn.

When the pattern design data A is corrected, the drawing coordinate offset data G obtained for each measurement point may be processed and used. For example, the drawing coordinate offset data G may be reflected in the pattern design data A by interpolating the data for each measurement point or normalizing it with a specific rule using the least square method.

Alternatively, the coordinate system of the drawing device may be corrected based on the coordinate value G for drawing, and the obtained correction coordinate system and the "pattern design data A" may be used for drawing. The reason for this is that a plurality of drawing devices have a function of specifically modifying the coordinate system that they have, and drawing them based on the modified coordinate system.

The drawing coordinate offset data G used at this time can also be processed in the same manner as described above.

Furthermore, the drawing method of the present invention is not limited to the above embodiment.

When drawing, it is also possible to appropriately mark the area other than the transfer pattern area. Patterns and the like are performed. As described below, the coordinate measurement mark pattern can be additionally drawn here.

For example, there is a case where the shape of the holding member which the exposure device has is different depending on the device as described above. In the exposure apparatus of the different means, when the model condition, the holding condition, and the vacuum pressure condition in the calculation of the finite element method are respectively given, the conditions may be appropriately changed.

Further, in the above aspect, the holding point of the photomask held by the holding member is limited to a plane (the smallest square plane of the substrate film surface). This treatment is such that the holding member holds the reticle on a single plane. However, in the case where the holding point cannot be mounted on a single plane due to the shape of the holding member, the shape of the holding member may be reflected when the forced shift amount is set in the step of obtaining the transfer surface shape data C.

Further, the order of the steps may be changed as long as the effects of the present invention are not impaired.

After the corrected pattern data is drawn on the mask base by the drawing method of the above aspect, the mask is manufactured by the patterning process.

About the patterning process

The mask base (photomask blank) that has been drawn is a mask by the following procedure.

For the patterning process, a known method can be applied. That is, the photoresist film which has been described is developed by a known developer to form a photoresist pattern. The photoresist pattern can be etched using the photoresist pattern as an etch mask.

A known method can be used for the etching method. Dry etching can be applied, and wet etching can also be applied. The present invention is particularly useful as a method of manufacturing a photomask for a display device, so that the effect of the present invention can be remarkably obtained when wet etching is applied.

Further, in the drawing step of the present invention described above, the object to be drawn is not only the mask base (the pattern for which the transfer pattern is not drawn), but also a plurality of films and a pattern formed on a part thereof. Semi-finished reticle.

A reticle substrate having a plurality of films for patterning each film The depiction step of the invention applies the depiction steps of the invention described above. In this case, it is extremely advantageous in that it is possible to manufacture a highly precise reticle having excellent superposition accuracy.

Depiction device

Furthermore, the present application encompasses inventions relating to a rendering device that can implement the rendering method described above.

That is, the drawing device is a drawing device for drawing a transfer pattern on a mask base on which a film and a photoresist film are formed on the main surface of the substrate.

The drawing device has the following mechanisms.

Height measuring mechanism

The height measuring mechanism is a mechanism for measuring the height distribution of the main surface in a state in which the mask base is placed on the table with the main surface on the upper side, and the height distribution data E at the drawing is obtained.

Input mechanism

The input mechanism is a mechanism that can input the pattern design data A of the transfer pattern and the transfer surface shape data C indicating the main surface shape of the substrate in which the substrate is held in the exposure apparatus.

Computing mechanism

The arithmetic unit calculates the coordinate amount G for drawing of the plurality of points on the main surface by using the above-described drawing height distribution data E and the transfer surface shape data C.

Further, the drawing device has a drawing means for drawing on the mask base using the drawing coordinate offset amount G and the pattern design material A.

Further, the drawing device of the present embodiment may include the following mechanism together with the height measuring mechanism.

Input mechanism

The input mechanism is a mechanism that can input the pattern design data A of the transfer pattern, the substrate surface shape data B indicating the shape of the main surface of the substrate, and the information related to the holding state when the substrate is held in the exposure device. And substrate property information including physical property values of the substrate material.

Computing mechanism

The calculation mechanism is a mechanism that converts the transfer surface shape of the main surface shape of the substrate in a state of being held in the exposure device using the substrate surface shape data B, the information on the holding state, and the substrate physical property information. The data C is used to calculate the coordinate offset data G for drawing a plurality of points on the main surface using the height-distribution data E and the transfer surface shape data C described above.

As the arithmetic means, for example, a known arithmetic device such as a personal computer can be used.

Depiction agency

The drawing mechanism is a mechanism for drawing on the mask base using the above-described drawing coordinate offset data G and the pattern design data A.

Furthermore, it is preferable that the drawing device includes a control mechanism that controls the input mechanism, the arithmetic unit, and the drawing unit.

Here, the information relating to the holding state is preferably, for example, a coordinate relating to the holding condition (the shape of the holding member or the substrate holding point where the substrate is in contact with the holding member when the substrate is held in the exposure device) (according to the coordinates) The information is used to estimate the forced shift amount of the holding point), and further includes information on the vacuum pressure condition (the amount of vacuum pressure and the area where the vacuum pressure is applied).

The substrate physical property information may be, for example, information indicating a Young's modulus, a Poisson's ratio, and a weight density of the substrate.

By using such a drawing device, the drawing steps required for the above-described mask manufacturing method can be carried out.

<Embodiment 2 (Check)>

As described above, according to the present invention, it is possible to obtain a photomask capable of making the coordinates of the pattern formed on the object to be processed extremely high.

Further, in the case of inspecting the reticle before leaving the factory, it is preferable to perform inspection in consideration of the difference between the reticle placed in the state of the inspection device and the reticle held in the state of the exposure device.

Therefore, the inventors found the necessity of a new inspection method.

VII Steps to obtain the pattern coordinate data L

The film surface (pattern forming surface) was placed on the upper surface, and the patterned photomask was placed on the table of the coordinate inspection device to measure the coordinates of the transfer pattern. The data obtained here is set as the pattern coordinate data L.

Here, the coordinate measurement is preferably performed by measuring the coordinates of the mark pattern formed on the main surface of the reticle simultaneously with the transfer pattern. The marking pattern is preferably a plurality of positions disposed on the main surface and outside the area of the transfer pattern.

VIII Steps to obtain the transfer surface shape data C

On the other hand, a transfer surface shape data C indicating the amount of deformation of the main surface caused by holding the photomask on the exposure device is obtained. This treatment is the same as the above steps II-1 to II-2.

In the case of the photomask of the present invention manufactured by applying the above-described drawing method, the transfer surface shape data C which has been obtained can be used.

IX Get the steps to check the height distribution data I

In the state where the film surface (pattern forming surface) is on the upper side and the photomask is placed on the table of the inspection apparatus, the height distribution of the main surface is measured to obtain the inspection height distribution data I.

The height measurement in this step is the same as the height measurement performed in the "Step of obtaining the height distribution data E at the time of drawing" in the above III. Moreover, preferably in the step, in the above The height of the step of III is determined by measuring the height of the same measuring point.

X Get the steps to check the differential data J

The inspection difference data J is obtained by obtaining the difference between the inspection height distribution data I and the transfer surface shape data C (see FIGS. 10( a ) to (d)).

XI Steps to Obtain Coordinate Offset Data K for Inspection

The coordinate offset K of the inspection is obtained by estimating the coordinate offset of the plurality of points on the main surface corresponding to the differential data J (see FIGS. 10(d) to (e)). Here, the step of converting the difference in height into the coordinate shift amount can be performed in the same manner as the above-described step V.

Further, the step of inspecting the transfer pattern is performed by using the obtained inspection coordinate offset amount K and the pattern coordinate data L to perform the inspection of the transfer pattern.

Specifically, the inspection pattern for the transfer pattern can be performed (compared) using the corrected design data M and the pattern coordinate data L obtained by reflecting the inspection coordinate offset amount K on the pattern design data A.

Alternatively, the inspection of the transfer pattern may be performed (compared) by using the corrected coordinate data N obtained by reflecting the inspection coordinate offset amount K on the pattern coordinate data L and the pattern design data A.

It is preferable to inspect the photomask manufactured by the manufacturing method of the present invention by the inspection method of the present invention.

Furthermore, the use of the photomask is not limited and its constitution is not limited.

It is clear that the effects of the present invention can be obtained in a photomask having a film structure such as a so-called binary mask, a multi-gray mask, or a phase shift mask.

Inspection device

Furthermore, the present invention encompasses an invention relating to an inspection apparatus which can carry out the inspection method as described above.

which is, An inspection apparatus for a photomask that inspects a photomask having a transfer pattern in which a thin film is patterned on a main surface of a substrate, and has a coordinate measuring mechanism that performs the above-described main surface The coordinates of the transfer pattern are measured to obtain the pattern coordinate data L. The height measuring mechanism measures the height distribution of the main surface in a state where the main surface is placed on the table while the main surface is on the upper side. And a height distribution data I at the time of inspection; an input mechanism that inputs a transfer surface shape data C indicating a shape of a main surface of the substrate in a state in which the substrate is held in an exposure device; and an arithmetic unit that uses the height distribution data I at the time of the inspection And the transfer surface shape data C to calculate a plurality of inspection coordinate offset data K on the main surface; and an inspection mechanism that uses the inspection coordinate offset data K and the pattern design data A to The transfer pattern of the photomask is inspected.

Further, the present invention includes the following inspection apparatus.

An inspection apparatus for inspecting a photomask having a transfer pattern patterned by a thin film on a main surface of a substrate, and the inspection apparatus includes a coordinate measuring mechanism formed on the above The coordinates of the transfer pattern on the main surface are measured to obtain the pattern coordinate data L; and the height measuring mechanism is configured such that the main surface is placed on the table while the main surface is on the upper side, and the main surface is The height distribution is measured to obtain the inspection height distribution data I; the input mechanism inputs the substrate surface shape data B indicating the shape of the main surface of the substrate, and information related to the holding state when the substrate is held in the exposure device, and a substrate physical property information including a physical property value of the substrate material; and an arithmetic unit that calculates the substrate held in the exposure device using the substrate surface shape data B, information related to the holding state, and the substrate physical property information The transfer surface shape data C of the main surface shape, and the inspection coordinate offset data K of the plurality of points on the main surface is calculated using the inspection height distribution data I and the transfer surface shape data C; and the inspection mechanism The pattern for the transfer of the photomask is inspected using the inspection coordinate offset data K and the pattern design data A described above.

The information relating to the state in which the substrate is held in the exposure apparatus and the substrate property information including the physical property values of the substrate material are as described above.

The transfer surface shape data C which indicates the main surface shape of the substrate held in the exposure apparatus means an operation for performing the same steps as the above steps II-1 to II-2.

When the transfer pattern for the photomask is inspected using the inspection coordinate offset data K and the pattern design data A, the comparison required for the step XI is performed (if necessary, the comparison operation is performed) ).

Display device manufacturing method

The present invention relates to a method of manufacturing a display device including patterning a device substrate having a processed layer by exposing a photomask having a transfer pattern formed on a main surface, including use of the present invention Method of manufacturing a display device for a photomask manufactured by the method.

That is, a method of manufacturing a display device using a photomask manufactured by the manufacturing method of the present invention, and applying the following pattern transfer method when manufacturing the photomask, that is, using a state that has been held in the exposure device The exposure device is determined to perform exposure. The pattern transferred to the object to be processed by pattern transfer is processed by etching or the like to form a display device.

Here, the optical performance of the exposure apparatus is, for example, the following effects, and the effects of the present invention are remarkable.

An exposure apparatus for use as an equal exposure for LCD (or for FPD (Flat Panel Display), liquid crystal), which has the following structure: The numerical aperture (NA) of the optical system is 0.08 to 0.15 (especially 0.08~) 0.10); the homology factor (σ) is 0.5 to 0.9; the exposure wavelength is light of exposure wavelength represented by any one of i-ray, h-ray, and g-ray, and particularly preferably includes i-ray, h-ray, and g-ray. Wide wavelength source.

When the photomask is provided in the exposure apparatus, it is preferably applied to the vacuum pressure applied in the above-described finite element method.

The layer to be processed refers to each layer of a constituent of a desired electronic device after being subjected to a transfer pattern having a transfer mask and then subjected to a process such as etching. For example, in the case of forming a TFT (Thin Film Transistor) circuit for driving a liquid crystal display device or an organic EL display device, a pixel layer, a source/drain layer, and the like can be exemplified.

The device substrate refers to a substrate having a circuit that is a constituent of an electronic device to be obtained, for example, a liquid crystal panel substrate, an organic EL panel substrate, or the like.

Furthermore, the present invention is directed to a display device including a plurality of masks in which a transfer pattern is formed on each of the main surfaces of each of the plurality of masks formed on the device substrate by pattern transfer. The manufacturing method includes using a photomask manufactured by the manufacturing method of the present invention.

The display device manufactured by applying the present invention has an extremely high overlap (overlay) of the layers. Therefore, the display device has a high yield and a high manufacturing efficiency.

[Examples]

The effect of the invention using the manufacturing method (drawing step) of the photomask of the present invention will be described using the schematic diagram shown in FIG.

Here, the following results are expressed: having a specific substrate surface shape (substrate surface) When the substrate (mask base) of the shape data B) is used for the transfer pattern, the accuracy of the coordinate of the transfer pattern provided in the exposure apparatus is determined by simulation to be finally formed. The result of the accuracy of the coordinates of the pattern on the print.

First, a specific test pattern is drawn on the reticle base using a drawing device. The test reticle base used here is a case where a light-shielding film and a positive-type resist film are formed on the main surface of the quartz substrate having a size of 850 mm × 1200 mm.

The pattern design data used herein is a test pattern including a cross pattern which is disposed on substantially the entire surface of the main surface at intervals of 75 mm in the X and Y directions. Further, the photoresist was developed, and the light-shielding film was wet-etched, whereby a test mask having a light-shielding film pattern was obtained. The test reticle was placed on the coordinate inspection device to perform coordinate measurement, and the result was as shown in Fig. 12(a).

Furthermore, the factor of the coordinate offset caused by the flatness of the table of the drawing device and the flatness of the table of the coordinate inspection device is determined by pre-measuring the flatness of the table of the two devices from FIG. 12(a). The data is removed.

Next, the coordinate offset of the state in which the test reticle was set in the exposure apparatus (equal projection exposure mode) was simulated. Here, using the shape information of the reticle holding member of the exposure machine, the vacuum pressure condition, and the substrate property information, the finite element method is used to estimate the coordinate offset generated by the test pattern to obtain the data of FIG. 12(b) (Comparative Example) ).

On the other hand, when the same test pattern is drawn on the reticle base, the coordinate system of the drawing machine is corrected to draw the pattern design data. When the coordinate system is corrected, the coordinates of the coordinates for drawing are obtained by the above steps II-1 to V. Fig. 12(c) shows the result of coordinate measurement by providing the test reticle obtained by the result to the coordinate inspection device.

Next, in the same manner as described above, the coordinate shift in the state in which the test reticle obtained as a result was set in the exposure apparatus was simulated. The results of the simulation are shown in Fig. 12 (d) (Example).

According to Fig. 12(d), it is understood that a transfer image closer to the pattern design material can be obtained on the transfer target than in Fig. 12(b). In the photomask manufactured by the method of the present invention, the coordinate accuracy is high, and the coordinate error value can be suppressed to less than 0.15 μm. That is, it is possible to set the accuracy of the error component substantially in addition to the coordinate offset due to the ability of the drawing device.

Claims (21)

A method of manufacturing a photomask comprising a photomask substrate prepared with a film and a photoresist film formed on a main surface of a substrate, and drawing a specific transfer pattern by a drawing device, and having: a step of preparing a pattern design material A by designing a transfer pattern; obtaining a transfer surface shape data C indicating a shape of the main surface when the photomask is held by the exposure device, and obtaining the main surface as an upper side a step of height-distributing the data E at the time of drawing the height distribution of the main surface in a state where the reticle substrate is placed on the table of the drawing device; and using the above-described height distribution data E and the transfer surface shape data C: obtaining a step of drawing the difference data F; estimating a coordinate offset corresponding to the difference data F on the plurality of points on the main surface to obtain a coordinate value G for drawing; and using the above Depicting a drawing step of drawing on the mask base with the coordinate offset data G and the pattern design data A; the transfer surface shape data C includes the amount of deformation of the main surface that is deformed by the force of the mask when the mask is held by the exposure device. A method of manufacturing a photomask comprising a photomask substrate prepared with a film and a photoresist film formed on a main surface of a substrate, and drawing a specific transfer pattern by a drawing device, and having: a step of preparing a pattern design material A for designing a transfer pattern; preparing a substrate sheet obtained by measuring a surface shape of the main surface a step of obtaining the transfer surface shape data C by shifting the surface shape based on the shape of the holding member on the substrate surface shape data B when the photomask is held in the exposure device; a step of measuring the height distribution of the main surface in a state where the mask surface is placed on the table of the drawing device while the main surface is on the upper side, and obtaining the height distribution data E at the drawing; a step of drawing the time difference data E and the transfer surface shape data C to obtain the difference data F, and estimating a coordinate offset of the plurality of points on the main surface corresponding to the drawing difference data F to obtain a coordinate for drawing a step of offset data G; and a drawing step of drawing on the mask base using the coordinate offset data G and the pattern design data A described above. The method of manufacturing a photomask according to claim 2, wherein in the step of obtaining the transfer surface shape data C, the finite element method is used. The method of manufacturing a reticle according to any one of claims 1 to 3, wherein in the drawing step, the correction pattern data H obtained by correcting the pattern design data A by using the coordinate offset amount G of the drawing is used. Make a description. The method of manufacturing a reticle according to any one of claims 1 to 3, wherein in the drawing step, the coordinate system of the drawing device is corrected based on the coordinate offset data G for the drawing, and the obtained correction coordinate is used. It is drawn by the above-mentioned pattern design material A. The method of manufacturing a reticle according to any one of claims 1 to 3, wherein, when the reticle is held in the exposure device, the plurality of holding points held by the holding member are disposed on a plane. The method of manufacturing the reticle of claim 2 or 3, wherein the substrate surface shape data B The position of the plurality of measurement points on the main surface is measured by holding the mask base or the substrate for forming the mask base in such a manner that the main surface is vertical. The method of manufacturing a reticle according to any one of claims 1 to 3, wherein the reticle base is a reticle base for manufacturing a display device having a side of 300 mm to 1500 mm. A drawing device for drawing a pattern for transfer on a mask base on which a film and a photoresist film are formed on a main surface of a substrate, and having a height measuring mechanism that causes the main surface to be upper side The mask base is placed on the table, and the height distribution of the main surface is measured to obtain the height distribution data E at the time of drawing; the input mechanism inputs the pattern design data A of the transfer pattern, indicating a substrate surface shape data B of a shape of a main surface of the substrate, information relating to a state in which the substrate is held in the exposure device, and substrate property information including physical property values of the substrate material; and an arithmetic mechanism using the substrate surface The shape data B, the information on the holding state, and the substrate physical property information, and the transfer surface shape data C indicating the main surface shape of the substrate held in the exposure apparatus is calculated, and the height distribution data E at the drawing is used. And the transfer surface shape data C, and calculating the coordinates of the coordinates of the plurality of points on the main surface The material G; and a drawing means for drawing on the mask base using the above-described drawing coordinate offset data G and the pattern design data A. The drawing device of claim 9, wherein the reticle base is a reticle substrate for manufacturing a display device having a side of 300 mm to 1500 mm. A method for inspecting a photomask, which is an inspection apparatus for inspecting a photomask having a transfer pattern in which a thin film is patterned on a main surface of a substrate, and having: a step of measuring the coordinates of the transfer pattern formed on the main surface to obtain the pattern coordinate data L while the photomask is placed on the table of the inspection apparatus; obtaining the mask a step of transferring the surface shape data C of the shape of the main surface at the time of the exposure device; and placing the photomask on the table of the inspection device while the main surface is the upper side, and the main surface is The height distribution is measured to obtain the height distribution data I of the inspection; the step of inspecting the difference data J is obtained by using the height distribution data I and the transfer surface shape data C described above; and the main body corresponding to the inspection difference data J is estimated a step of determining the coordinate value K for inspection using the coordinate offset of a plurality of points on the surface; and performing the transfer pattern using the coordinate value K for inspection and the pattern coordinate data L a step of inspecting; the transfer surface shape data C includes the main body deformed by the force of the photomask when the photomask is held by the exposure device Amount of deformation of the surface. A method for inspecting a photomask, wherein an inspection device is used to inspect a photomask having a transfer pattern in which a thin film is patterned on a main surface of a substrate, and the photomask is placed on the inspection a step of obtaining a pattern coordinate data L by performing coordinate measurement on the transfer pattern formed on the main surface in a state on a table of the apparatus; preparing a substrate surface obtained by measuring a surface shape of the main surface a step of shape data B; when the reticle is held in the exposure device, the displacement generated in the surface shape based on the shape of the holding member is reflected on the surface shape data B of the substrate a step of transferring the surface shape data C; and measuring the height distribution of the main surface to obtain a height distribution during inspection by placing the photomask on the upper surface of the inspection apparatus while the main surface is on the upper side a step of the data I; obtaining the step of examining the difference data J by using the height distribution data I and the transfer surface shape data C; and estimating a coordinate offset of the plurality of points on the main surface corresponding to the inspection difference data J The step of obtaining the coordinate value K for inspection is obtained by the amount, and the step of inspecting the transfer pattern by using the coordinate value K for inspection and the pattern coordinate data L. The method of inspecting a photomask according to claim 12, wherein in the step of obtaining the transfer surface shape data C, the finite element method is used. The method of inspecting a reticle according to any one of claims 11 to 13, wherein in the step of performing the inspection of the transfer pattern, the coordinate value K for the inspection is reflected in the pattern design data A. The design data M and the pattern coordinate data L are corrected to perform the inspection of the transfer pattern. The method of inspecting a photomask according to any one of claims 11 to 13, wherein in the step of performing the inspection of the transfer pattern, the inspection coordinate offset amount K is reflected in the pattern coordinate data L. The corrected coordinate data N and the pattern design data A are obtained to perform the inspection of the transfer pattern. The method of inspecting a reticle according to any one of claims 11 to 13, wherein the reticle base is a reticle base for manufacturing a display device having a side of 300 mm to 1500 mm. A method of manufacturing a reticle, comprising: a step of preparing a reticle substrate on which a film and a photoresist film are formed on a main surface; a step of patterning the film; and utilizing any one of claims 11 to 13 Checking method of the inspection method of the item's mask Step. A manufacturing method of a display device, comprising: a step of preparing a photomask manufactured by the method for manufacturing a photomask according to any one of claims 1 to 3, and having a photomask formed on a main surface; and The step of patterning the device substrate having the processed layer by exposing the mask. A method for manufacturing a display device, comprising: a plurality of photomasks and an exposure device for forming a transfer pattern on a main surface of each of the plurality of processed layers formed on the device substrate; Further, it is characterized in that, as the plurality of reticle, a manufacturer of the reticle according to any one of claims 1 to 3 is used. An inspection apparatus for a photomask that inspects a photomask having a transfer pattern in which a thin film is patterned on a main surface of a substrate, and has a coordinate measuring mechanism that performs the above-described main surface The coordinates of the transfer pattern are measured to obtain the pattern coordinate data L. The height measuring mechanism measures the height distribution of the main surface in a state where the main surface is placed on the table while the main surface is on the upper side. And obtaining an inspection height distribution data I; an input mechanism inputting a substrate surface shape data B indicating a shape of a main surface of the substrate, information related to a holding state when the substrate is held in the exposure device, and including the substrate material The substrate physical property information of the physical property value; the calculation mechanism uses the substrate surface shape data B, the information related to the holding state, and the substrate physical property information to calculate the main surface shape of the substrate held in the exposure apparatus Transfer surface shape data C, and use the above-mentioned inspection height distribution data I and the above transfer surface shape And computing the expected C The inspection coordinate offset data K of the plurality of points on the main surface; and the inspection mechanism for inspecting the transfer pattern of the photomask using the inspection coordinate offset data K and the pattern design data A . The inspection apparatus of the reticle of claim 20, wherein the reticle base is a reticle base for manufacturing a display device having a side of 300 mm to 1500 mm.