CN116577961A

CN116577961A - FPD photomask, method for forming position measurement mark for FPD photomask, and method for manufacturing FPD photomask

Info

Publication number: CN116577961A
Application number: CN202310086669.6A
Authority: CN
Inventors: 桥本昌典
Original assignee: SK Electronics Co Ltd
Current assignee: SK Electronics Co Ltd
Priority date: 2022-02-08
Filing date: 2023-01-18
Publication date: 2023-08-11
Also published as: KR20230120090A; TW202332984A; JP2023115863A

Abstract

The present invention provides a photomask for an FPD, which forms a mark for position measurement for ensuring the position accuracy of unit patterns arranged in two dimensions in a proper form. A photomask (1) for an FPD is provided with: a pattern forming region (1A) which is formed by two-dimensionally arranging a plurality of unit pattern forming regions (1 Aa) and … … in a first direction (x) and a second direction (y) which are orthogonal to each other, the first direction (x) and the second direction (y) having a space (1 Ab) around the pattern forming region; an outer edge region (1B) surrounding the pattern formation region (1A); and a plurality of position measurement marks (3A); the position measurement mark (3A) is formed by a combination of a line along the first direction (x) and a line along the second direction (y), and is formed only at a portion where the blank section (1 Ab) intersects in the pattern forming region (1A).

Description

FPD photomask, method for forming position measurement mark for FPD photomask, and method for manufacturing FPD photomask

Technical Field

The present invention relates to a photomask for an FPD, a method for forming a mark for measuring a position of the photomask for an FPD, and a method for manufacturing the photomask for an FPD.

Background

The display of small information devices such as mobile phones, smartphones, mobile personal computers, and tablet personal computers is an FPD (Flat Panel Display: flat panel display) mainly composed of a small panel, and a liquid crystal display, a plasma display, an organic EL display, or the like is used.

In the production of a panel, a photolithography technique is used in which a pattern is formed on a transparent substrate coated with a photosensitive material by exposing the pattern of a photomask to light. In the case of a small panel, from the viewpoint of improving productivity, a large-sized photomask in which a plurality of unit patterns corresponding to one small panel are two-dimensionally arranged is used, and a plurality of small panels are simultaneously produced.

The photomask includes a pattern forming region and an outer edge region. The pattern forming region is a region containing all unit patterns. The outer edge region is a region surrounding the pattern forming region. A position measurement mark is formed in the outer edge region. Conventionally, position accuracy of a unit pattern has been ensured by performing position measurement on a position measurement mark in an outer edge region.

However, the distance between each unit pattern and the position measurement mark is not the same, but is different depending on the position of each unit pattern. In addition, a positional shift of a partial pattern may occur in a pattern formation region due to an error occurring in a manufacturing process of a photomask (mainly, a drawing process of a resist pattern). Therefore, the conventional assurance method has a problem of lack of accuracy.

In order to solve this problem, there has been proposed a photomask, which is different in the type of photomask from the viewpoint of the type of photomask used for a semiconductor integrated circuit, instead of a photomask for an FPD, but in the pattern formation region, a position measurement mark is provided in a space between adjacent unit pattern formation regions or in a space which circumscribes the outermost unit pattern formation region, and the position measurement mark is used to ensure the positional accuracy of each unit pattern (patent document 1).

Prior art literature

Patent literature

Patent document 1, japanese patent laid-open publication No. 2001-201844

Disclosure of Invention

Problems to be solved by the invention

However, the position measurement mark described in patent document 1 is formed in a blank portion (cut region) between adjacent unit pattern forming regions, and thus the position measurement mark extends into the unit pattern forming region. This means that an unnecessary pattern is formed in the unit pattern forming region, and is not preferable. In particular, in recent years, with the increase in resolution of FPDs, patterns have become finer, allowing the room for formation of unnecessary patterns to gradually disappear.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a photomask for an FPD in which a position measurement mark is formed in an appropriate form.

The present invention also provides a method for forming a position measurement mark of a photomask for an FPD, which can form a position measurement mark of an appropriate form.

Further, the present invention provides a method for manufacturing a photomask for an FPD, which can improve the overlay accuracy of each layer when the photomask is composed of a plurality of layers.

Means for solving the problems

A photomask for an FPD of the present invention comprises: a pattern forming region including a plurality of unit pattern forming regions each having a space in the periphery thereof and two-dimensionally arranged in a first direction and a second direction orthogonal to each other; an outer edge region surrounding the pattern forming region; and a plurality of position measurement marks; the position measurement mark is formed of a combination of a line in the first direction and a line in the second direction, and is formed only at a portion where the space portion intersects in the pattern forming region.

Here, as an embodiment of the FPD photomask of the present invention, the following configuration may be adopted: the position measurement mark is configured in such a manner that a line along the first direction and a line along the second direction intersect, and in the pattern formation region, an intersection of the two lines is arranged so as to coincide with an intersection of the center line of the space.

In addition, as an embodiment of the FPD photomask of the present invention, the following configuration may be adopted: the position measurement mark is formed by intersecting a line in the first direction and a line in the second direction, and is divided into an inner portion and an outer portion.

In this case, the following structure may be adopted: one of the inner portion and the outer portion is composed of a laminated film including a first functional film and a second functional film; the other of the inner portion and the outer portion is composed of the first functional film or the second functional film.

The functional film is a film having a function of adjusting the optical characteristics of exposure light. The functional film includes a phase shift film having a function of changing a phase of exposure light, a semipermeable film having a function of adjusting transmittance of exposure light, a light shielding film having a function of shielding exposure light, and the like.

In addition, as another embodiment of the FPD photomask of the present invention, the following configuration may be adopted: the position measurement mark is in a form in which a line in the first direction and a line in the second direction intersect, and in a form in which an intersection of the two lines is cut off.

Further, as still another embodiment of the FPD photomask of the present invention, the following configuration may be adopted: a mark for position measurement is also formed in the outer edge region.

Further, as still another embodiment of the FPD photomask of the present invention, the following configuration may be adopted: the outer edge region is provided with a registration mark composed of a line having a line width thicker than that of the line constituting the position measurement mark.

In addition, the method for forming the mark for measuring the position of the photomask for the FPD of the present invention divides the mark for measuring the position into a first pattern and a second pattern; forming a first pattern through a first patterning process and a second patterning process or through the first patterning process; the second pattern is formed through a second patterning process.

Here, as an embodiment of the method for forming a mark for position measurement of an FPD photomask of the present invention, the following configuration may be adopted: performing a first patterning process on a photomask blank having a first functional film formed on a transparent substrate; after the first patterning step, a second functional film is laminated and formed, and then the second patterning step is performed.

In addition, as another embodiment of the method for forming a mark for position measurement of an FPD photomask of the present invention, the following configuration may be adopted: performing a first patterning step on a photomask blank in which a first functional film is formed on a transparent substrate, an intermediate film having etching characteristics different from those of the first functional film is formed on the first functional film, and a second functional film having etching characteristics identical to those of the first functional film is formed on the intermediate film; after the first patterning process, the intermediate film is etched away, and then a second patterning process is performed.

In addition, as another embodiment of the method for forming a mark for position measurement of an FPD photomask of the present invention, the following configuration may be adopted: performing a first patterning step on a photomask blank having a first functional film formed on a transparent substrate and a second functional film having etching characteristics different from those of the first functional film formed on the first functional film; the first patterning process is followed by a second patterning process.

In addition, the method for manufacturing the FPD photomask according to the present invention is a method for manufacturing a second and subsequent photomask of a multi-layer structure in which a plurality of photomasks are used as a set and each photomask is used as a layer, wherein the offset amounts and offset angles in the first and second orthogonal directions are obtained from the position measurement results of the position measurement marks provided in the first photomask manufactured previously, coordinate values of drawing data are converted by using these values, the drawing data are corrected, and a patterning process is performed based on the corrected drawing data.

Effects of the invention

According to the FPD photomask of the present invention, the mark for position measurement is constituted by a combination of a line in the first direction and a line in the second direction, and in the pattern forming region, the mark for position measurement is formed only at a portion where the blank portion crosses. Thus, the position measurement mark does not extend into the unit pattern formation region, and an unnecessary pattern is not formed in the unit pattern formation region. Therefore, according to the FPD photomask of the present invention, it is possible to provide the FPD photomask in which the position measurement marks are formed in an appropriate form.

Further, according to the method for forming a mark for position measurement of an FPD photomask of the present invention, the alignment accuracy of the photomask can be confirmed by checking the mark for position measurement formed by dividing into the first patterning step and the second patterning step. Therefore, according to the method for forming the mark for position measurement of the FPD photomask of the present invention, a mark for position measurement of an appropriate form can be provided.

Further, according to the method for manufacturing an FPD photomask of the present invention, in an FPD photomask in which a plurality of photomasks are used as a set and each photomask is used as a layer and is configured in a plurality of layers, the overlay error of each layer can be minimized. Therefore, according to the method for manufacturing the FPD photomask of the present invention, the overlay accuracy of each layer in the case where the photomask is configured in a plurality of layers can be improved.

Drawings

Fig. 1 is a schematic plan view of a photomask according to the present embodiment.

Fig. 2 (a) is an explanatory diagram of an example of the position measurement result of the position measurement marker. Fig. 2 (b) is an explanatory diagram of another example of the position measurement result of the position measurement marker.

Fig. 3 (a) is a plan view of the position measurement marker according to embodiment 1. Fig. 3 (b) is a cross-sectional view taken along line A-A of fig. 3 (a).

Fig. 4 is an explanatory diagram of a method of forming the position measurement mark according to embodiment 1.

Fig. 5 (a) is a plan view of the position measurement marker according to embodiment 2. Fig. 5 (B) is a cross-sectional view taken along line B-B of fig. 5 (a).

Fig. 6 is an explanatory diagram of a method of forming the position measurement mark according to embodiment 2.

Fig. 7 is an explanatory diagram next to fig. 6.

Fig. 8 (a) is a plan view of a position measurement marker according to embodiment 3. Fig. 8 (b) is a cross-sectional view of the C-C line of fig. 8 (a).

Fig. 9 is an explanatory diagram of a method of forming the position measurement mark according to embodiment 3.

Fig. 10 is an explanatory diagram next to fig. 9.

Fig. 11 (a) is a plan view of a position measurement marker according to embodiment 4. Fig. 11 (b) is a sectional view taken along line D-D of fig. 11 (a).

Fig. 12 is an explanatory diagram of a method of forming the position measurement mark according to embodiment 4.

Fig. 13 is an explanatory diagram next to fig. 12.

Fig. 14 (a) is a partially enlarged schematic plan view of a photomask according to another embodiment 1. Fig. 14 (b) is a plan view of a position measurement marker according to other embodiment 1.

Fig. 15 (a) and 15 (b) are explanatory views of a method for manufacturing a photomask according to an application example.

Symbol description

1: photomask, 1A: pattern forming region, 1Aa: unit pattern forming region, 1Ab: blank, 1B: outer edge region, 2: transparent substrate, 3a to 3C: position measurement mark, 3a: line, 3b: inner part, 3c: outer part, 4: alignment mark, 5: light shielding film, 6: semipermeable membrane, 7: intermediate film (etching stopper film), 8: resist film, wx, wy: line width, lx, ly of line: length of line, gx, gy: width of gap, Δx: offset in first direction x, Δy: offset in the second direction y, θ: offset angle.

Detailed Description

< photomask for FPD >)

An embodiment of a photomask for an FPD according to the present invention will be described below with reference to fig. 1 and 2. In addition, an actual FPD photomask is a large-sized photomask having a size of 330mm or more and 450mm or more. For easy understanding, the unit pattern formation region 1Ab is appropriately deformed with respect to the entire size of the photomask 1, the number of rows and columns of the matrix, the total number, and the like in fig. 1.

As shown in fig. 1, the photomask 1 has a rectangular shape as a whole, and includes a pattern forming region 1A and an outer edge region 1B on a transparent substrate 2. The pattern formation region 1A has a rectangular shape. In the pattern forming region 1A, a plurality of unit pattern forming regions 1Aa, … … each corresponding to one small panel have a space 1Ab around each of them, and the plurality of unit pattern forming regions 1Aa, … … are two-dimensionally arranged in the first direction x and the second direction y which are orthogonal to each other. The unit pattern forming region 1Aa is also rectangular. The blank space 1Ab is a grid shape having a predetermined width, and is a cut region in the panel. The outer edge region 1B is a region surrounding the pattern formation region 1A.

In the pattern formation region 1A, a position measurement mark 3A is formed at a portion where the space 1Ab intersects. In the outer edge region 1B, a position measurement mark 3B is formed in a frame-like region along a rectangular dividing line of the pattern formation region 1A. The position measurement mark 3B corresponds to a conventional position measurement mark, and the position measurement mark 3A is supplemented. In the present embodiment, the position measurement marks 3B are formed along the corners of the four places and the opposite sides of the dividing line. The position measurement marks 3 (3A, 3B) are read by a coordinate measuring device to ensure positional accuracy of the unit patterns arranged two-dimensionally. The position measurement mark 3 is formed at the time of patterning of the pattern formation region 1A. That is, the unit pattern of the pattern formation region 1A is formed and the position measurement marks 3 are formed in a patterning process by a simultaneous process.

The position measurement mark 3 is constituted by a combination of a line along the first direction x and a line along the second direction y. As an example, the position-measuring marks 3 cross each other at the midpoints by lines of the same length, and have a + (plus) shape.

An alignment mark 4 is formed in the outer edge region 1B. In the present embodiment, the alignment marks 4 are formed at corners around. The alignment mark 4 is read by a reader provided in the exposure apparatus, and is used to set the photomask 1 at an appropriate position in the exposure apparatus. The alignment mark 4 is formed at the time of patterning of the pattern formation region 1A. That is, the unit pattern of the pattern formation region 1A is formed and the alignment mark 4 is formed by simultaneous processing in the patterning step.

The alignment mark 4 is formed by a combination of a line along the first direction x and a line along the second direction y. As an example, the alignment marks 4 cross each other at the midpoints by lines of the same length, and have a + (plus) shape. However, since the resolution of the reading device included in the exposure device is lower than the resolution of the coordinate measuring device, the line width of the line constituting the alignment mark 4 is thicker than the line width of the line constituting the position measuring mark 3.

The positional accuracy of each unit pattern can be confirmed by performing positional measurement on the position measurement mark 3A located in the vicinity thereof. Fig. 2 a shows that the position measurement mark 3A is displaced in the counterclockwise direction with respect to the original position (indicated by the intersection of the broken lines), that is, each unit pattern is displaced in the counterclockwise direction. Fig. 2 (b) shows that the position measurement mark 3A is displaced in the clockwise direction with respect to the original position, that is, each unit pattern is displaced in the clockwise direction. In this way, by performing position measurement on the plurality of position measurement marks 3A, … … in the pattern forming region 1A, the position accuracy of each unit pattern can be accurately confirmed.

Further, if the positional deviation of the position measurement mark 3A is within the allowable range, the accuracy of the photomask can be ensured. Alternatively, even when the positional deviation of the position measurement marks 3A is out of the allowable range, the deviation amounts and the deviation angles in the first direction x and the second direction y may be obtained from the positional measurement results of the position measurement marks 3A, and the drawing data may be corrected based on these values, thereby improving the accuracy of the photomask. Alternatively, by correcting the position where the photomask is set in the exposure apparatus based on these values, a panel with high accuracy can be produced as a result.

The unit pattern forming region 1Aa is rectangular with an aspect ratio at a constant ratio, and the position measurement marks 3A are disposed at four corners of the similar shape of the unit pattern forming region 1Aa, that is, at each intersection of the center lines of the spaces 1 Ab. More specifically, the position measurement marks 3A are arranged at the respective intersections of the center lines of the spaces 1Ab so that the intersections of the two orthogonal lines of the position measurement marks 3A coincide with the intersections of the center lines of the spaces 1 Ab. As a result, as shown in fig. 2, the presence or absence of the positional deviation (error) of the positional measurement result of each position measurement marker 3A and the amount thereof can be expressed by a mesh model that can be easily understood. Therefore, the positional accuracy of the unit pattern can be easily understood and confirmed visually.

Further, the position-measuring mark 3A is constituted by a combination of a line along the first direction x and a line along the second direction y, and in the pattern-forming region 1A, the position-measuring mark 3A is formed only at a portion where the space 1Ab intersects. The first direction x and the second direction y coincide with the longitudinal direction of the space 1 Ab. In addition, the position measurement marks of the same form are not formed in the middle portion of the space portion 1Ab, that is, in the portion between the adjacent unit pattern forming regions 1Aa and 1 Aa. Thus, even if the adjacent unit pattern forming regions 1Aa, 1Aa are closer, the width of the blank 1Ab is narrower, and the position measurement mark 3A does not extend into the unit pattern forming region 1Aa, so that an unnecessary pattern is not formed in the unit pattern forming region 1 Aa. Accordingly, the photomask 1 in which the position measurement marks 3A are formed in an appropriate form can be provided.

A position measurement mark 3B is also formed at an appropriate portion of the outer edge region 1B. That is, the position measurement mark 3B is also formed in the vicinity of the mark (alignment mark 4) that serves as a reference of the exposure apparatus. By performing position measurement on the mark 3B, the position accuracy of the entire pattern can be confirmed.

< mark (1) for position measurement >

Here, the position measurement marks 3 (3A, 3B) according to embodiment 1 will be described with reference to fig. 3 and 4.

As shown in fig. 3, the position measurement mark 3 is constituted by a combination of a line 3a along the first direction x and a line 3a along the second direction y. The two lines 3a, 3a have the same line width (wx=wy) and the same length (lx=ly), and intersect each other at the midpoint. Thus, the position measurement mark 3 has a + (plus sign) shape. In addition, the central portions of the two lines 3a, 3a are cut out with the same width (gx=gy). Thus, the position measurement mark 3 has a hollowed-out structure in which the intersection of the two lines 3a and 3a is cut off. The hollow structure is adopted because, when the coordinate measuring device is used for measurement, the two lines 3a and 3a are obviously overlapped at the intersection, which is not preferable for measurement.

The line widths Wx, wy of the lines 3a are 0.7 μm or more and 1.0 μm or less. This is a line width that can be read by a coordinate measuring device, and is a line width at which the line 3a is not resolved on the panel in an exposure process (equivalent projection exposure because of being for an FPD) by an exposure device using the photomask 1. The lengths Lx, ly of the lines 3a are 100 μm or more and 200 μm or less. This is the length that the coordinate measuring device is easy to read. The gap widths Gx, gy are 10 μm or more and 20 μm or less. The same applies to embodiments 2 to 4 described below.

The position measurement mark 3 is formed on the transparent substrate 2. The transparent substrate 2 is a substrate of synthetic quartz glass or the like. The transparent substrate 2 has a transmittance of 95% or more with respect to a representative wavelength (for example, i line, h line, or g line) included in the exposure light used in the exposure process using the photomask 1. The exposure light may be, for example, i-line, h-line, or g-line, or may be mixed light including at least two of them. Alternatively, the exposure light may be light whose wavelength band is shifted or extended to the short wavelength side and/or the long wavelength side with respect to the light. As an example, the wavelength band of the exposure light may be applied to a wavelength band extending from a broadband range of 365nm to 436nm to 300nm to 450 nm. However, the exposure light is not limited thereto.

The position measurement mark 3 is constituted by a light shielding film 5. The light shielding film 5 was used: cr-based materials among known materials such as Cr or Cr-based compounds, ni or Ni-based compounds, ti or Ti-based compounds, si-based compounds, and metal silicide compounds. In the present embodiment, a Cr-based compound is used for the light shielding film 5. The light shielding film 5 has a transmittance of 1% or less with respect to a representative wavelength included in the exposure light. Alternatively, the optical density (OD value) of the light shielding portion may be 2.7 or more. As an example, the light shielding film 5 has a laminated structure including a first film formation layer and a second film formation layer. The first film layer is made of a Cr film, and is light-shielding. The second film-forming layer is composed of a chromium oxide film for the purpose of suppressing reflection. In this case, even if the transmittance of the first film-forming layer is higher than 1%, the laminated transmittance of the first film-forming layer and the second film-forming layer may be 1% or less.

Next, a method for forming the position measurement marks 3 (3A, 3B) according to embodiment 1 will be described.

This forming method is performed in a simultaneous processing manner in the manufacturing method of the photomask 1,

i) Photomask blank preparation Process (Process 1)

ii) resist film Forming step (step 2)

iii) Drawing step (step 3)

iv) developing step (step 4)

v) light-shielding film etching step (step 5)

vi) resist film removal step (step 6).

The resist film forming step (step 2) to the resist film removing step (step 6) are referred to as patterning steps. In the patterning step, the position measurement mark 3 is patterned (simultaneously with the patterning of the unit pattern).

In the photomask blank preparing step (step 1), as shown in fig. 4 (a-1) and (a-2), a photomask blank having a light-shielding film 5 formed on a transparent substrate 2 is prepared. The light shielding film 5 is formed by sputtering, vapor deposition, or the like.

As shown in fig. 4 (b-1) and (b-2), in the resist film forming step (step 2), the resist film 8 is formed by uniformly coating the resist on the light shielding film 5. The resist is coated by a coating method or a spray method.

In the drawing step (step 3), the resist film 8 is irradiated with exposure light using an electron beam or a laser beam of a drawing device, and a resist pattern corresponding to the position measurement mark 3 is drawn.

In the development step (step 4), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. The development is performed by immersing in a developer. The drawing step (step 3) and the developing step (step 4) are collectively referred to as a resist pattern forming step.

In the light shielding film etching step (step 5), the exposed portion of the light shielding film 5 is removed by etching using the resist pattern as a mask for etching treatment. The etching may be either dry etching or wet etching, but if it is a large-sized photomask, wet etching is preferable. The etchant uses an etching liquid or an etching gas.

As shown in fig. 4 (c-1) and (c-2), in the resist film removal step (step 6), the resist film 8 is removed. The resist film 8 is removed by ashing or immersing in a resist stripping liquid.

Through the above steps 1 to 6, the position measurement mark 3 is completed (simultaneously with completion of the photomask 1).

< mark (2) for position measurement >

Next, the position measurement marks 3 (3A, 3B) according to embodiment 2 will be described with reference to fig. 5 to 7.

As shown in fig. 5, the position measurement mark 3 is constituted by a combination of a line 3a along the first direction x and a line 3a along the second direction y. The two lines 3a, 3a have the same line width and the same length, and intersect each other at the midpoint. Thus, the position measurement mark 3 has a + (plus sign) shape. Further, the central portions of the two lines 3a, 3a are cut out with the same width. Thus, the position measurement mark 3 has a hollowed-out structure in which the intersection of the two lines 3a and 3a is cut off. Furthermore, the two wires 3a, 3a have a gap therebetween so as to be divided into an inner portion 3b and an outer portion 3c. The inner portion 3b constitutes a first pattern of the position-measuring marks 3. The outer portion 3c constitutes a second pattern of the position-measuring marks 3. Thus, the position measurement mark 3 is composed of a first pattern and a second pattern that are physically separated.

The inner portion 3b of the position measurement mark 3 is composed of a laminated film of a light shielding film 5 and a semipermeable film 6. The light shielding film 5 and the semipermeable film 6 are made of the same material, specifically, cr-based material. In the present embodiment, a Cr-based compound is used for the light shielding film 5 and the semipermeable film 6. Alternatively, a material other than Cr may be used for the semipermeable membrane 6. The semipermeable membrane 6 is a phase shift membrane. Alternatively, the semipermeable membrane 6 may be a halftone membrane. The semipermeable membrane 6 is set to have a transmittance lower than that of the transparent substrate 2 and higher than that of the light shielding membrane 5 for a representative wavelength included in the exposure light, and to have a transmittance of 5% to 70% for the representative wavelength. The semipermeable membrane 6 may be a semipermeable metal membrane in which the transmittance distribution in the plane of the photomask 1 is improved by adjusting the nitrogen content. Further, by incorporating other elements into the semipermeable membrane 6, the optical density (OD value) of the semi-transmissive portion thereof can be changed.

In the inner portion 3b of the position measurement mark 3, a semipermeable membrane 6 is formed on the light shielding film 5. The line of the semipermeable membrane 6 is formed to be slightly longer and wider than the line of the light shielding membrane 5. Thereby, both end surfaces of the line of the light shielding film 5 are covered with the semipermeable film 6 to be protected. The inner portion 3b is formed with a margin at the peripheral edge by making the line of the semipermeable membrane 6 slightly larger than the line of the light shielding membrane 5.

The outer portion 3c of the position measurement mark 3 is composed of the same semipermeable membrane 6 as the semipermeable membrane 6 that is the uppermost layer of the inner portion 3 b. In the present embodiment, the shape of the outer portion 3c is the same as the line of the light shielding film 5 of the inner portion 3 b.

In fig. 5 to 7, the light shielding film 5 and the semipermeable film 6 are shown to have the same thickness. However, this is for convenience, and the actual thickness of the light shielding film 5 and the semipermeable film 6 may be appropriately set.

Next, a method for forming the position measurement marks 3 (3A, 3B) according to embodiment 2 will be described.

i) Photomask blank preparation Process (Process 1)

ii) resist film Forming step (step 2)

iii) Drawing step (step 3)

iv) developing step (step 4)

v) light-shielding film etching step (step 5)

vi) resist film removal step (step 6)

vii) semipermeable Membrane Forming step (step 7)

viii) resist film Forming Process (Process 8)

ix) drawing Process (Process 9)

x) developing step (step 10)

xi) semi-permeable Membrane etching step (step 11)

xii) resist film removal step (step 12).

The steps from the resist film forming step (step 2) to the resist film removing step (step 6) are referred to as a first patterning step, and the steps from the resist film forming step (step 8) to the resist film removing step (step 12) are referred to as a second patterning step. In the first patterning step, the first pattern of the position measurement mark 3 is patterned (simultaneously with the first patterning of the unit pattern), and in the second patterning step, the first pattern and the second pattern of the position measurement mark 3 are patterned (simultaneously with the second patterning of the unit pattern).

In the photomask blank preparing step (step 1), as shown in fig. 6 (a-1) and (a-2), a photomask blank having a light-shielding film 5 formed on a transparent substrate 2 is prepared. The light shielding film 5 is formed by sputtering, vapor deposition, or the like.

As shown in fig. 6 (b-1) and (b-2), in the first resist film forming step (step 2), a resist is uniformly applied to the light shielding film 5 to form a resist film 8. The resist is coated by a coating method or a spray method.

In the first drawing step (step 3), the resist film 8 is irradiated with exposure light using an electron beam or a laser beam of a drawing device, and a resist pattern corresponding to the inner portion 3b of the position measurement mark 3 is drawn.

In the first development step (step 4), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. The development is performed by immersing in a developer. The first drawing step (step 3) and the first developing step (step 4) are collectively referred to as a first resist pattern forming step.

As shown in fig. 6 (c-1) and (c-2), in the first resist film removal step (step 6), the resist film 8 is removed. The resist film 8 is removed by ashing or immersing in a resist stripping liquid.

As shown in fig. 7 (a-1) and (a-2), in the semipermeable membrane forming step (step 7), the semipermeable membrane 6 is formed on the exposed portion of the transparent substrate 2 from which the light shielding film 5 is removed and the light shielding film 5. The semipermeable membrane 6 is formed by sputtering, vapor deposition, or the like.

As shown in fig. 7 (b-1) and (b-2), in the second resist film forming step (step 8), the resist film 8 is formed by uniformly coating the semipermeable film 6 with the resist. The resist is coated by a coating method or a spray method.

In the second drawing step (step 9), the resist film 8 is irradiated with exposure light using an electron beam or a laser beam of a drawing device, and a resist pattern corresponding to the inner portion 3b and the outer portion 3c of the position measurement mark 3 is drawn. Here, the resist pattern corresponding to the inner portion 3b is set to be slightly longer and wider than the resist pattern corresponding to the inner portion 3b in the first drawing step (step 3).

In the second development step (step 10), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. The development is performed by immersing in a developer. The second drawing step (step 9) and the second developing step (step 10) are collectively referred to as a second resist pattern forming step.

In the semipermeable membrane etching step (step 11), the exposed portion of the semipermeable membrane 6 is removed by etching using the resist pattern as a mask for etching treatment. The etching may be either dry etching or wet etching, but if it is a large-sized photomask, wet etching is preferable. The etchant uses an etching liquid or an etching gas. At this time, the light shielding film 5 is protected from etching by the semipermeable film 6.

As shown in fig. 7 (c-1) and (c-2), in the second resist film removal step (step 12), the resist film 8 is removed. The resist film 8 is removed by ashing or immersing in a resist stripping liquid.

Through the above steps 1 to 12, the position measurement mark 3 is completed (simultaneously with completion of the photomask 1).

In this way, the position measurement mark 3 is formed by dividing it into a first patterning step and a second patterning step. In more detail, the inner portion 3b (first pattern) of the position-measuring mark 3 is formed by a first patterning process and a second patterning process, and the outer portion 3c (second pattern) of the position-measuring mark 3 is formed by a second patterning process. Therefore, when an alignment error occurs between the first patterning step and the second patterning step, the inner portion 3b and the outer portion 3c are formed to be offset. Therefore, by checking the position measurement marks 3, the alignment accuracy of the photomask 1 can be confirmed.

< mark (3) for position measurement >

Next, the position measurement marks 3 (3A, 3B) according to embodiment 3 will be described with reference to fig. 8 to 10.

As shown in fig. 8, the position measurement mark 3 is constituted by a combination of a line 3a along the first direction x and a line 3a along the second direction y. The two lines 3a, 3a have the same line width and the same length, and intersect each other at the midpoint. Thus, the position measurement mark 3 has a + (plus sign) shape. Further, the central portions of the two lines 3a, 3a are cut out with the same width. Thus, the position measurement mark 3 has a hollowed-out structure in which the intersection of the two lines 3a and 3a is cut off. Furthermore, the two wires 3a, 3a have a gap therebetween so as to be divided into an inner portion 3b and an outer portion 3c. The inner portion 3b constitutes a first pattern of the position-measuring marks 3. The outer portion 3c constitutes a second pattern of the position-measuring marks 3. Thus, the position measurement mark 3 is composed of a first pattern and a second pattern that are physically separated.

The inner portion 3b of the position measurement mark 3 is composed of a laminated film of a semipermeable film 6, an intermediate film (etching stopper film) 7, and a light shielding film 5. The light shielding film 5 and the semipermeable film 6 are made of the same material, specifically, cr-based material. In the present embodiment, a Cr-based compound is used for the light shielding film 5 and the semipermeable film 6. The interlayer 7 is made of a non-Cr material. In this embodiment, ni, ti, or molybdenum silicide compound is used for the interlayer 7. Alternatively, the light shielding film 5 and the semipermeable film 6 may be made of a non-Cr material, and the intermediate film 7 may be made of Cr material.

Since the light shielding film 5 and the semipermeable film 6 are made of the same material, etching characteristics are the same. However, since the light shielding film 5, the semipermeable film 6, and the intermediate film 7 are different in material, etching characteristics are different. That is, the light shielding film 5 and the semipermeable film 6 have etching selectivity with respect to the intermediate film 7, and the intermediate film 7 has etching selectivity with respect to the light shielding film 5 and the semipermeable film 6.

In the inner portion 3b of the position measurement mark 3, an intermediate film 7 is formed on the semipermeable film 6, and a light shielding film 5 is formed on the intermediate film 7. The line of the semipermeable membrane 6 is formed to be slightly longer and wider than the line of the light shielding membrane 5 and the intermediate membrane 7. Thus, the semipermeable membrane 6 protrudes from both end surfaces and both side surfaces of the line of the light shielding membrane 5 and the intermediate membrane 7. The inner portion 3b is formed with a margin at the peripheral edge by making the line of the semipermeable membrane 6 slightly larger than the lines of the light shielding membrane 5 and the intermediate membrane 7.

The outer portion 3c of the position measurement mark 3 is composed of the same semipermeable membrane 6 as the semipermeable membrane 6 of the lowermost layer of the inner portion 3 b. In the present embodiment, the shape of the outer portion 3c is the same as the line of the light shielding film 5 and the intermediate film 7 of the inner portion 3 b.

In fig. 8 to 10, the semipermeable membrane 6, the intermediate membrane 7, and the light shielding membrane 5 are shown to have the same thickness. However, this is for convenience, and the actual thicknesses of the semipermeable membrane 6, the intermediate membrane 7, and the light shielding membrane 5 may be appropriately set.

Next, a method for forming the position measurement marks 3 (3A, 3B) according to embodiment 3 will be described.

i) Photomask blank preparation Process (Process 1)

ii) resist film Forming step (step 2)

iii) Drawing step (step 3)

iv) developing step (step 4)

v) light-shielding film etching step (step 5)

vi) resist film removal step (step 6)

vii) intermediate film etching step (step 7)

viii) resist film Forming Process (Process 8)

ix) drawing Process (Process 9)

x) developing step (step 10)

xi) semi-permeable Membrane etching step (step 11)

xii) resist film removal step (step 12).

As shown in fig. 9 (a-1) and (a-2), in the photomask blank preparing step (step 1), a photomask blank having a semipermeable membrane 6 formed on a transparent substrate 2, an intermediate membrane 7 formed on the semipermeable membrane 6, and a light shielding membrane 5 formed on the intermediate membrane 7 is prepared. The semipermeable membrane 6, the intermediate membrane 7, and the light shielding membrane 5 are formed by a sputtering method, a vapor deposition method, or the like.

As shown in fig. 9 (b-1) and (b-2), in the first resist film forming step (step 2), a resist is uniformly applied to the light shielding film 5 to form a resist film 8. The resist is coated by a coating method or a spray method.

In the light shielding film etching step (step 5), the exposed portion of the light shielding film 5 is removed by etching using the resist pattern as a mask for etching treatment. The etching may be either dry etching or wet etching, but if it is a large-sized photomask, wet etching is preferable. The etchant uses an etching liquid or an etching gas. In any case, an etchant having etching selectivity to the light shielding film 5 (etchant that does not etch the intermediate film 7) is used.

As shown in fig. 9 (c-1) and (c-2), in the first resist film removal step (step 6), the resist film 8 is removed. The resist film 8 is removed by ashing or immersing in a resist stripping liquid.

As shown in fig. 10 (a-1) and (a-2), in the intermediate film etching step (step 7), the exposed portion of the intermediate film 7 is removed by etching using the light shielding film 5 as a mask for etching treatment. The etching may be either dry etching or wet etching, but if it is a large-sized photomask, wet etching is preferable. The etchant uses an etching liquid or an etching gas. In either case, an etchant having etching selectivity to the intermediate film 7 (an etchant that does not etch the light shielding film 5 and the semipermeable film 6) is used.

As shown in fig. 10 (b-1) and (b-2), in the second resist film forming step (step 8), the resist film 8 is formed by uniformly coating the light shielding film 5 and the semipermeable film 6 with a resist. The resist is coated by a coating method or a spray method.

In the semipermeable membrane etching step (step 11), the exposed portion of the semipermeable membrane 6 is removed by etching using the resist pattern as a mask for etching treatment. The etching may be either dry etching or wet etching, but if it is a large-sized photomask, wet etching is preferable. The etchant uses an etching liquid or an etching gas. In either case, an etchant having etching selectivity to the semipermeable film 6 (etchant that does not etch the intermediate film 7) is used. However, the intermediate film 7 is protected by a resist and is not etched originally. Further, the light shielding film 5 is also protected by a resist and is not etched.

As shown in fig. 10 (c-1) and (c-2), in the second resist film removal step (step 12), the resist film 8 is removed. The resist film 8 is removed by ashing or immersing in a resist stripping liquid.

< mark (4) for position measurement >

Next, the position measurement marks 3 (3A, 3B) according to embodiment 4 will be described with reference to fig. 11 to 13.

As shown in fig. 11, the position measurement mark 3 is constituted by a combination of a line 3a along the first direction x and a line 3a along the second direction y. The two lines 3a, 3a have the same line width and the same length, and intersect each other at the midpoint. Thus, the position measurement mark 3 has a + (plus sign) shape. Further, the central portions of the two lines 3a, 3a are cut out with the same width. Thus, the position measurement mark 3 has a hollowed-out structure in which the intersection of the two lines 3a and 3a is cut off. Furthermore, the two wires 3a, 3a have a gap therebetween so as to be divided into an inner portion 3b and an outer portion 3c. The inner portion 3b constitutes a first pattern of the position-measuring marks 3. The outer portion 3c constitutes a second pattern of the position-measuring marks 3. Thus, the position measurement mark 3 is composed of a first pattern and a second pattern that are physically separated.

The inner portion 3b of the position measurement mark 3 is composed of a laminated film of a semipermeable film 6 and a light shielding film 5. The light shielding film 5 is made of Cr-based material. In the present embodiment, a Cr-based compound is used for the light shielding film 5. The semipermeable membrane 6 is made of a non-Cr material. In the present embodiment, ni, ti or molybdenum silicide compound is used for the semipermeable membrane 6. Alternatively, a non-Cr material may be used for the light shielding film 5, and a Cr material may be used for the semipermeable film 6.

The light shielding film 5 and the semipermeable film 6 are different in etching characteristics due to different materials. That is, the light shielding film 5 has etching selectivity with respect to the semipermeable film 6, and the semipermeable film 6 has etching selectivity with respect to the light shielding film 5.

In the inner portion 3b of the position measurement mark 3, a light shielding film 5 is formed on the semipermeable membrane 6. The lines of the light shielding film 5 are the same shape as the lines of the semipermeable film 6.

The outer portion 3c of the position measurement mark 3 is composed of the same semipermeable membrane 6 as the semipermeable membrane 6 of the lowermost layer of the inner portion 3 b. In the present embodiment, the shape of the outer portion 3c is the same shape as the inner portion 3 b.

In fig. 11 to 13, the semipermeable membrane 6 and the light shielding membrane 5 are shown to have the same thickness. However, this is for convenience, and the actual thickness of the semipermeable membrane 6 and the light shielding membrane 5 may be appropriately set.

Next, a method for forming the position measurement marks 3 (3A, 3B) according to embodiment 4 will be described.

i) Photomask blank preparation Process (Process 1)

ii) resist film Forming step (step 2)

iii) Drawing step (step 3)

iv) developing step (step 4)

v) light-shielding film etching step (step 5)

vi) resist film removal step (step 6)

vii) resist film Forming step (step 7)

viii) drawing Process (Process 8)

ix) development Process (Process 9)

x) semi-permeable Membrane etching Process (Process 10)

xi) resist film removal step (step 11).

The steps from the resist film forming step (step 2) to the resist film removing step (step 6) are referred to as a first patterning step, and the steps from the resist film forming step (step 7) to the resist film removing step (step 11) are referred to as a second patterning step. In the first patterning step, the first pattern of the position measurement mark 3 is patterned (simultaneously with the first patterning of the unit pattern), and in the second patterning step, the second pattern of the position measurement mark 3 is patterned (simultaneously with the second patterning of the unit pattern).

As shown in fig. 12 (a-1) and (a-2), in a photomask blank preparing step (step 1), a photomask blank having a semipermeable membrane 6 formed on a transparent substrate 2 and a light shielding membrane 5 formed on the semipermeable membrane 6 is prepared. The semipermeable membrane 6 and the light shielding membrane 5 are formed by sputtering, vapor deposition, or the like.

As shown in fig. 12 (b-1) and (b-2), in the first resist film forming step (step 2), a resist is uniformly applied to the light shielding film 5 to form a resist film 8. The resist is coated by a coating method or a spray method.

In the light shielding film etching step (step 5), the exposed portion of the light shielding film 5 is removed by etching using the resist pattern as a mask for etching treatment. The etching may be either dry etching or wet etching, but if it is a large-sized photomask, wet etching is preferable. The etchant uses an etching liquid or an etching gas. In any case, an etchant having etching selectivity to the light shielding film 5 (etchant that does not etch the semipermeable film 6) is used.

As shown in fig. 12 (c-1) and (c-2), in the first resist film removal step (step 6), the resist film 8 is removed. The resist film 8 is removed by ashing or immersing in a resist stripping liquid.

As shown in fig. 13 (a-1) and (a-2), in the second resist film forming step (step 7), the resist film 8 is formed by uniformly coating the light shielding film 5 and the semipermeable film 6 with a resist. The resist is coated by a coating method or a spray method.

In the second drawing step (step 8), the resist film 8 is irradiated with exposure light using an electron beam or a laser beam of a drawing device, and a resist pattern corresponding to the outer portion 3c of the position measurement mark 3 is drawn.

In the second development step (step 9), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. The development is performed by immersing in a developer. The second drawing step (step 8) and the second developing step (step 9) are collectively referred to as a second resist pattern forming step.

In the semipermeable membrane etching step (step 10), the exposed portion of the semipermeable membrane 6 is removed by etching using the resist pattern as a mask for etching treatment. The etching may be either dry etching or wet etching, but if it is a large-sized photomask, wet etching is preferable. The etchant uses an etching liquid or an etching gas. In any case, an etchant having etching selectivity to the translucent film 6 (etchant that does not etch the light shielding film 5) is used.

As shown in fig. 13 (b-1) and (b-2), in the second resist film removal step (step 11), the resist film 8 is removed. The resist film 8 is removed by ashing or immersing in a resist stripping liquid.

Through the above steps 1 to 11, the position measurement mark 3 is completed (simultaneously with completion of the photomask 1).

In this way, the position measurement mark 3 is formed by dividing it into a first patterning step and a second patterning step. In more detail, the inner portion 3b (first pattern) of the position-measuring mark 3 is formed by a first patterning process, and the outer portion 3c (second pattern) of the position-measuring mark 3 is formed by a second patterning process. Therefore, when an alignment error occurs between the first patterning step and the second patterning step, the inner portion 3b and the outer portion 3c are formed to be offset. Therefore, by checking the position measurement marks 3, the alignment accuracy of the photomask 1 can be confirmed.

Application example (method for manufacturing photomask for FPD composed of multiple layers) >

In a conventional manufacturing method of an FPD photomask having a plurality of photomasks as a set and each photomask as a layer and being formed in a plurality of layers, reference coordinates are set in a drawing apparatus, and a patterning process is performed based on drawing data using CAD data described by the reference coordinates. Thus, the position measurement of each photomask represents an error relative to the reference coordinates. The drawing device or the coordinate measuring device has a certain measurement error. Therefore, in the case where the positions of the reference layer and the superimposed layer are shifted from the reference coordinates, the superimposed error becomes large.

Thus, the following manufacturing method was used: the offset amount and the offset angle are obtained from the position measurement result (see fig. 15 a) of the position measurement mark provided in the photomask (reference mask serving as the reference layer) manufactured previously, and the coordinate values of the drawing data are converted and corrected by using these values, and the patterning step is performed based on the corrected drawing data. First, as described with reference to fig. 15 (b), a patterning process is performed on the reference mask based on drawing data described using reference coordinates, as usual. After the reference mask is manufactured, the position of the position measurement mark provided in the reference mask is measured, and the offset amount Δx in the first direction x, the offset amount Δy in the second direction y, and the offset angle θ are obtained from the position measurement result. Then, the drawing data of the second and subsequent photomasks are corrected by converting the coordinate values by the values of Δx, Δy, and θ, respectively. Then, patterning steps are performed on the second and subsequent photomasks based on the corrected drawing data.

As described above, according to the method for manufacturing the FPD photomask of the application example, the drawing result of the reference layer is the reference coordinates of the superimposed layer, and the overlay error between the reference layer and the superimposed layer can be minimized. Therefore, according to the method for manufacturing the FPD photomask of the application example, the overlay accuracy of the reference layer and the overlay layer can be improved. That is, the method for manufacturing the FPD photomask according to the application example is a technique for pursuing the overlay accuracy of each layer in addition to the allowable positional deviation, and is a technique that is superior in terms of delivery period and cost compared to a technique for manufacturing the reference mask again by correcting the drawing data.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

In embodiments 1 to 4 described above, the position measurement mark 3 has a hollowed-out structure in which the intersection of the two lines 3a and 3a is cut out. However, the present invention is not limited thereto. The position measurement mark may be in a form in which the intersection of two lines is overlapped without being cut off.

In embodiments 1 to 4, the position measurement mark 3 has a + (plus) shape in which two orthogonal lines 3a and 3a intersect each other at the midpoint. However, the present invention is not limited thereto. For example, the position measurement mark may have an L shape by intersecting two orthogonal lines at the end points, or a T shape by intersecting one of the two orthogonal lines at the midpoint and the other at the end points. Of course, in these cases, it can be appropriately set whether or not the intersection of the two lines is cut off.

In embodiments 1 to 4, the two lines 3a and 3a of the position measurement mark 3 are lines parallel to the first direction x and the second direction y. However, the present invention is not limited thereto. The lines constituting the position measurement marks may have some angles with respect to the first direction x and the second direction y. "in the first direction" and "in the second direction" are meant to include such a configuration.

In embodiments 1 to 4, the position measurement mark 3A is formed only at the portion where the space 1Ab intersects in the pattern formation region 1A. However, the present invention is not limited thereto. As shown in fig. 14, if the position measurement mark 3C is formed in such a manner that the length Lx of one line 3a is short and does not extend into the unit pattern formation region 1Aa, it may be formed in the middle portion of the space portion 1Ab, that is, in a portion between adjacent unit pattern formation regions 1Aa and 1 Aa.

In embodiment 1, a photomask blank having a light-shielding film 5 formed on a transparent substrate 2 is used. In embodiment 2, a photomask blank having a light-shielding film 5 formed on a transparent substrate 2 is used, and after the first patterning step, a semipermeable film 6 is laminated. In embodiment 3, a photomask blank in which a semipermeable membrane 6 is formed on a transparent substrate 2, an intermediate membrane 7 is formed on the semipermeable membrane 6, and a light shielding membrane 5 is formed on the intermediate membrane 7 is used. In embodiment 4, a photomask blank in which a semipermeable membrane 6 is formed on a transparent substrate 2 and a light shielding membrane 5 is formed on the semipermeable membrane 6 is used. However, the present invention is not limited thereto. Among these, the light shielding film and the semipermeable film may be replaced. Further, the functional film may be a light shielding film or a semipermeable film.

In embodiments 1 to 4, it is assumed that the position measurement mark 3A is formed at a portion of the pattern formation region 1A intersecting the space 1 Ab. However, in the method for forming the mark for position measurement of the FPD photomask according to the present invention, which is the embodiment 2 to 4, the forming position of the mark for position measurement is not particularly limited. The method for forming a position measurement mark for an FPD photomask of the present invention is novel and novel, regardless of the position measurement mark.

In addition, in the above embodiments 1 to 4, the inner portion 3b of the position measurement mark 3A constitutes the first pattern, and the outer portion 3c constitutes the second pattern. However, the present invention is not limited thereto. The outer portion of the position measurement mark may be formed in a first pattern, and the inner portion may be formed in a second pattern.

In addition, in the above embodiments 1 to 4, the first pattern and the second pattern divide the position measurement mark 3 into the inner area and the outer area. However, the present invention is not limited thereto. For example, it may be appropriately set: one line of the position measurement mark constitutes a first pattern, the other line constitutes a second pattern, and the like, and a method of dividing the first pattern and the second pattern.

Industrial applicability

The photomask of the present invention can be used for an FPD to perform exposure using a known exposure apparatus. For example, as the exposure device, an equivalent projection exposure device using exposure light of a single wavelength or a broadband light source having a peak at 300 to 500nm may be used, and an equivalent optical system having a Numerical Aperture (NA) of about 0.09 (0.07 to 0.12) and having a conventionally known coherence factor (σ) may be used. The numerical aperture is preferably 0.12 or more. Of course, the photomask of the present invention can also be used as a photomask for proximity exposure.

Claims

1. A photomask for an FPD, comprising:

a pattern forming region formed by two-dimensionally arranging a plurality of unit pattern forming regions having a space around the pattern forming region in a first direction and a second direction orthogonal to each other; an outer edge region surrounding the pattern forming region; and a plurality of position measurement marks;

it is characterized in that the method comprises the steps of,

the position measurement mark is formed of a combination of a line in the first direction and a line in the second direction, and is formed only at a portion where the space portion intersects in the pattern forming region.

2. The FPD photomask according to claim 1, wherein the position measurement mark is in a form in which a line along the first direction and a line along the second direction intersect, and in the pattern formation region, an intersection of the two lines is arranged so as to coincide with an intersection of a center line of the space.

3. A photomask for an FPD according to claim 1 or 2, wherein the position measurement mark is formed in a form in which a line in the first direction and a line in the second direction intersect, and is divided into an inner portion and an outer portion.

4. The FPD photomask according to claim 3, wherein one of the inner portion and the outer portion is composed of a laminated film including a first functional film and a second functional film; the other of the inner portion and the outer portion is composed of the first functional film or the second functional film.

5. The photomask for an FPD according to any one of claims 1 to 4, wherein the position measurement mark is in a form in which a line in the first direction and a line in the second direction intersect, and in which an intersection of the two lines is cut.

6. The photomask for an FPD according to any one of claims 1 to 5, wherein the mark for position measurement is also formed in the outer edge region.

7. The FPD photomask according to any one of claims 1 to 6, wherein the outer edge region is provided with an alignment mark composed of a line having a line width thicker than that of a line constituting the position measurement mark.

8. A method for forming a mark for measuring the position of a photomask for an FPD, characterized in that,

dividing the mark for position measurement into a first pattern and a second pattern;

forming a first pattern through a first patterning process and a second patterning process or through the first patterning process;

the second pattern is formed through a second patterning process.

9. The method for forming a mark for position measurement of an FPD photomask according to claim 8, wherein,

performing a first patterning process on a photomask blank having a first functional film formed on a transparent substrate;

after the first patterning step, a second functional film is laminated and formed, and then the second patterning step is performed.

10. The method for forming a mark for position measurement of an FPD photomask according to claim 8, wherein,

performing a first patterning step on a photomask blank in which a first functional film is formed on a transparent substrate, an intermediate film having etching characteristics different from those of the first functional film is formed on the first functional film, and a second functional film having etching characteristics identical to those of the first functional film is formed on the intermediate film;

after the first patterning process, the intermediate film is etched away, and then a second patterning process is performed.

11. The method for forming a mark for position measurement of an FPD photomask according to claim 8, wherein,

performing a first patterning step on a photomask blank having a first functional film formed on a transparent substrate and a second functional film having etching characteristics different from those of the first functional film formed on the first functional film;

the first patterning process is followed by a second patterning process.

12. A method for manufacturing a photomask for an FPD, which is a method for manufacturing a second and subsequent photomask of a plurality of photomasks as a set and each photomask as a layer and having a plurality of layers, characterized in that the offset and offset angle in the first and second orthogonal directions are obtained from the position measurement result of the position measurement mark provided in the first photomask manufactured previously, coordinate values of drawing data are converted by using these values, the drawing data are corrected, and a patterning step is performed based on the corrected drawing data.