Photomask for FPD, method of forming position measurement mark in photomask for FPD and manufacturing method of photomask for fpd

Abstract

To provide a photomask for an FPD by which a position measurement mark used for guaranteeing the position accuracy of each unit pattern arranged in two-dimension is formed in a preferred form.SOLUTION: A photomask 1 for an FPD includes a pattern forming area 1A in which a plurality of unit pattern forming areas 1Aa,... are two-dimensionally arranged along a first direction x and a second direction y that have a margin portion 1Ab in the surroundings and are orthogonal to each other; an outer periphery area 1B surrounding the pattern forming area 1A and a plurality of position measurement marks 3A,..., wherein the position measurement mark 3A is composed by combining a line along the first direction x and a line along the second direction y, and is formed only in a portion where the margin portions 1Ab intersect in the pattern forming area 1A.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a photomask for an FPD, a method for forming a position measurement mark in a photomask for an FPD, and a method for manufacturing a photomask for an FPD.

Background Art

[0002] Displays of small information devices such as mobile phones, smartphones, mobile personal computers, and tablets are mainly small-panel FPDs (Flat Panel Displays), and liquid crystal displays, plasma displays, organic EL displays, etc. are used.

[0003] In panel production, photolithography technology is used to form a pattern on a transparent substrate by exposing the pattern of a photomask on a transparent substrate coated with a photosensitive material. In the case of small panels, from the perspective of productivity improvement, a large-sized photomask in which a plurality of unit patterns corresponding to each small panel are two-dimensionally arranged is used, and a plurality of small panels are produced simultaneously.

[0004] This photomask includes a pattern formation region and an outer edge region. The pattern formation region is a region that includes all unit patterns. The outer edge region is a region that surrounds the pattern formation region. A position measurement mark is formed in the outer edge region. Conventionally, the position accuracy of the unit pattern was guaranteed by measuring the position of the position measurement mark in the outer edge region.

[0005] However, the distances between each unit pattern and the position measurement mark are not the same and vary depending on the position of each unit pattern. Also, due to errors that occur in the manufacturing process of the photomask (mainly the resist pattern drawing process), local pattern misalignment may occur within the pattern formation region. Therefore, the conventional guarantee method has a problem of lacking accuracy.

[0006] To solve this problem, a photomask has been proposed that is not for FPDs but for semiconductor integrated circuits, and is of a different type, but provides position measurement marks in the margins between adjacent unit pattern formation regions and in the margins circumscribing the outermost unit pattern formation region in the pattern formation region, and uses these to guarantee the positional accuracy of each unit pattern (Patent Document 1). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2001-201844 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the position measurement marks described in Patent Document 1 are formed in the margins (cutting areas) between adjacent unit pattern formation areas, resulting in the position measurement marks encroaching on the unit pattern formation areas. This means that unnecessary patterns are formed in the unit pattern formation areas, which is undesirable. In particular, with the recent increase in resolution of FPDs, patterns have become more detailed, and there is no longer any room to tolerate the formation of unnecessary patterns.

[0009] Therefore, the present invention has been made in view of these circumstances, and aims to provide a photomask for an FPD in which position measurement marks are formed in a suitable form.

[0010] In addition, the present invention aims to provide a method for forming position measurement marks in a photomask for an FPD that can form position measurement marks in a suitable form.

[0011] Furthermore, the present invention aims to provide a method for manufacturing a photomask for an FPD that can improve the superposition accuracy of each layer when the photomask is composed of multiple layers. [Means for solving the problem]

[0012] The photomask for FPD according to the present invention is A photomask for an FPD comprising a pattern-forming region in which multiple unit pattern-forming regions are arranged in two dimensions along a first and second orthogonal direction with a margin around the periphery, an outer edge region surrounding the pattern-forming region, and multiple position measurement marks, The position measurement marks consist of a combination of lines along a first direction and lines along a second direction, and are formed only at the points where the margins intersect within the pattern formation area. This is a photomask for flat panel displays (FPDs).

[0013] Here, as one embodiment of the photomask for FPD according to the present invention, The position measurement mark is formed in a form where a line along the first direction and a line along the second direction intersect, and is divided into an inner portion and an outer portion. This configuration can be adopted.

[0014] Also, in this case, One of the inner and outer portions is composed of a laminated film including a first functional film and a second functional film, and the other of the inner and outer portions is composed of either the first functional film or the second functional film. This configuration can be adopted. A functional film is a film that has the function of adjusting the optical properties of exposure light. Functional films include phase-shift films that have the function of changing the phase of exposure light, semi-permeable films that have the function of adjusting the transmittance of exposure light, and light-shielding films that have the function of blocking exposure light.

[0015] Furthermore, another embodiment of the photomask for FPD according to the present invention is: Position measurement marks are also formed in the outer edge region. A configuration with [something] can be adopted.

[0016] Also, the method for forming a position measurement mark in a photomask for an FPD according to the present invention is divide the position measurement mark into a first pattern and a second pattern, by the first patterning step and the second patterning step, or by the first patterning step, form the first pattern, and form the second pattern by the second patterning step It is a method for forming a position measurement mark in a photomask for an FPD.

[0017] Here, as one aspect of the method for forming a position measurement mark in a photomask for an FPD according to the present invention, perform the first patterning step on a photomask blank in which a first functional film is formed on a transparent substrate, after the first patterning step, laminate and form a second functional film, and then perform the second patterning step A configuration with [something] can be adopted.

[0018] Also, as another aspect of the method for forming a position measurement mark in a photomask for an FPD according to the present invention, 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 the same etching characteristics as the first functional film is formed on the intermediate film. Perform the first patterning step on the photomask blank, after the first patterning step, etch and remove the intermediate film, and then perform the second patterning step A configuration with [something] can be adopted.

[0019] Also, as another aspect of the method for forming a position measurement mark in a photomask for an FPD according to the present invention, On a transparent substrate, a first functional film is formed, and on the first functional film, a photomask blank is formed with a second functional film having etching characteristics different from those of the first functional film. A first patterning step is performed. After the first patterning step, a second patterning step is performed. A configuration as described above can be adopted.

[0020] Also, a method for manufacturing a photomask for an FPD according to the present invention is as follows. A method for manufacturing a second and subsequent photomasks of a photomask for an FPD composed of a plurality of layers, where a plurality of photomasks are set as one set and each photomask is regarded as one layer. Based on the position measurement results of the position measurement marks provided on the first manufactured photomask, the deviation amounts and deviation angles in the first direction and the second direction perpendicular to each other are obtained. The coordinate values of the drawing data are converted using these values to correct the drawing data, and a patterning step is performed based on the corrected drawing data. It is a method for manufacturing a photomask for an FPD.

Advantages of the Invention

[0021] According to the photomask for an FPD according to the present invention, the position measurement marks are composed of a combination of lines along the first direction and lines along the second direction, and are formed only at the portions where the margins intersect in the pattern formation region. As a result, the position measurement marks do not enter the unit pattern formation region, and no unnecessary patterns are formed in the unit pattern formation region. Therefore, according to the photomask for an FPD according to the present invention, it is possible to provide a photomask for an FPD in which the position measurement marks are formed in a suitable form.

[0022] Furthermore, according to the method for forming position measurement marks in a photomask for FPDs according to the present invention, the alignment accuracy of the photomask can be confirmed by inspecting the position measurement marks formed in a first patterning step and a second patterning step. For this reason, the method for forming position measurement marks in a photomask for FPDs according to the present invention can provide a position measurement mark in a suitable form.

[0023] Furthermore, according to the method for manufacturing a photomask for an FPD according to the present invention, in a photomask for an FPD composed of multiple layers, where multiple photomasks form a set and each photomask is a single layer, the overlapping error of each layer can be minimized. Therefore, according to the method for manufacturing a photomask for an FPD according to the present invention, the overlapping accuracy of each layer can be improved when the photomask is composed of multiple layers. [Brief explanation of the drawing]

[0024] [Figure 1] Figure 1 is a schematic plan view of the photomask according to this embodiment. [Figure 2] Figure 2(a) is an explanatory diagram illustrating an example of the position measurement results for a position measurement mark. Figure 2(b) is an explanatory diagram illustrating another example of the position measurement results for a position measurement mark. [Figure 3] Figure 3(a) is a plan view of a position measurement mark according to Embodiment 1. Figure 3(b) is a cross-sectional view taken along line AA of Figure 3(a). [Figure 4] Figure 4 is an explanatory diagram of the method for forming position measurement marks according to Embodiment 1. [Figure 5] Figure 5(a) is a plan view of the position measurement mark according to Embodiment 2. Figure 5(b) is a cross-sectional view of Figure 5(a) along line BB. [Figure 6] Figure 6 is an explanatory diagram of the method for forming position measurement marks according to Embodiment 2. [Figure 7] Figure 7 is a continuation of the explanatory diagram in Figure 6. [Figure 8]Fig. 8(a) is a plan view of the position measurement mark according to Embodiment 3. Fig. 8(b) is a cross-sectional view taken along line C-C of Fig. 8(a). [Figure 9] Fig. 9 is an explanatory diagram of a method for forming the position measurement mark according to Embodiment 3. [Figure 10] Fig. 10 is a subsequent explanatory diagram of Fig. 9. [Figure 11] Fig. 11(a) is a plan view of the position measurement mark according to Embodiment 4. Fig. 11(b) is a cross-sectional view taken along line D-D of Fig. 11(a). [Figure 12] Fig. 12 is an explanatory diagram of a method for forming the position measurement mark according to Embodiment 4. [Figure 13] Fig. 13 is a subsequent explanatory diagram of Fig. 12. [Figure 14] 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 the position measurement mark according to Another Embodiment 1. [Figure 15] Figs. 15(a) and (b) are explanatory diagrams of a method for manufacturing a photomask according to an application example.

Embodiments for Carrying out the Invention

[0025] <Photomask for FPD> Hereinafter, an embodiment of a photomask for an FPD according to the present invention will be described with reference to Figs. 1 and 2. Note that an actual photomask for an FPD is a large-sized photomask having a size of 330 mm or more × 450 mm or more. Fig. 1 is described by appropriately deforming the size of the unit pattern formation region 1Ab, the number of rows and columns of the matrix, and the total number, etc. with respect to the entire photomask 1 for easy understanding.

[0026] As shown in Figure 1, the photomask 1 is rectangular overall and comprises a pattern formation region 1A and an outer edge region 1B on a transparent substrate 2. The pattern formation region 1A is rectangular. Within the pattern formation region 1A, a plurality of unit pattern formation regions 1Aa, ... each corresponding to a single small panel are arranged in a two-dimensional manner along a first direction x and a second direction y, with a margin region 1Ab around the periphery. The unit pattern formation region 1Aa is also rectangular. The margin region 1Ab is a grid with a predetermined width and forms a cutting region in the panel. The outer edge region 1B is the region surrounding the pattern formation region 1A.

[0027] In the pattern formation region 1A, position measurement marks 3A are formed at the intersections of the margins 1Ab. In the outer edge region 1B, position measurement marks 3B are formed in the frame-shaped region along the rectangular dividing lines of the pattern formation region 1A. Position measurement marks 3B correspond to conventional position measurement marks and complement position measurement marks 3A. In this embodiment, position measurement marks 3B are formed at the four corners and along the two opposing sides of the dividing lines. Position measurement marks 3 (3A, 3B) are read by a coordinate measuring device and used to guarantee the positional accuracy of each unit pattern arranged in two dimensions. Position measurement marks 3 are formed during pattern formation in the pattern formation region 1A. That is, the formation of the unit patterns in the pattern formation region 1A and the formation of position measurement marks 3 are performed simultaneously in the patterning process.

[0028] The position measurement mark 3 is composed of a combination of a line along the first direction x and a line along the second direction y. For example, the position measurement mark 3 has a + (plus) shape when lines of the same length intersect at their midpoints.

[0029] Alignment marks 4 are formed in the outer edge region 1B. In this embodiment, the alignment marks 4 are formed at four corners. The alignment marks 4 are read by a reading device provided in the exposure apparatus and used to set the photomask 1 in the correct position in the exposure apparatus. The alignment marks 4 are formed when the pattern is formed in the pattern formation region 1A. That is, the formation of the unit pattern in the pattern formation region 1A and the formation of the alignment marks 4 are performed simultaneously in the patterning process.

[0030] The alignment mark 4 is composed of a combination of a line along the first direction x and a line along the second direction y. For example, the alignment mark 4 has a plus (+) shape because lines of the same length intersect at their midpoints. However, because the reading device of the exposure device has lower resolution than the coordinate measurement device, the line width of the lines constituting the alignment mark 4 is thicker than the line width of the lines constituting the position measurement mark 3.

[0031] The positional accuracy of each unit pattern can be confirmed by measuring the position of the position measurement marks 3A located in the vicinity. Figure 2(a) shows that the position measurement marks 3A have shifted counterclockwise from their original position (represented by the intersection of the dashed lines), meaning that each unit pattern has shifted counterclockwise. Figure 2(b) shows that the position measurement marks 3A have shifted clockwise from their original position, meaning that each unit pattern has shifted clockwise. In this way, the positional accuracy of each unit pattern can be accurately confirmed by measuring the positions of multiple position measurement marks 3A, ... in the pattern formation region 1A.

[0032] Furthermore, if the misalignment of the position measurement marks 3A is within the acceptable range, the photomask is guaranteed to be accurate. Alternatively, even if the misalignment of the position measurement marks 3A is outside the acceptable range, the accuracy of the photomask can be improved by determining the amount and angle of misalignment in the first direction x and the second direction y from the position measurement results of each position measurement mark 3A, and correcting the drawing data based on these values. Alternatively, by correcting the position in which the photomask is set in the exposure device based on these values, a highly accurate panel can be produced as a result.

[0033] Furthermore, the unit pattern formation region 1Aa is rectangular in shape with a fixed aspect ratio, and the position measurement marks 3A are placed at the four corners of the similar shape of the unit pattern formation region 1Aa, that is, at each intersection of the centerlines of the margin area 1Ab. More specifically, the position measurement marks 3A are placed at each intersection of the centerlines of the margin area 1Ab such that the intersection of two orthogonal lines of the position measurement marks 3A coincides with the intersection of the centerlines of the margin area 1Ab. As a result, the position measurement results of each position measurement mark 3A can be represented by a grid model that makes it easy to understand the presence or absence and amount of positional deviation (error), as shown in Figure 2. Therefore, the positional accuracy of the unit pattern can be visually confirmed in an easy-to-understand manner.

[0034] Furthermore, the position measurement marks 3A are composed of a combination of a line along a first direction x and a line along a second direction y, and are formed only in the portion where the margin portion 1Ab intersects within the pattern formation region 1A. The first direction x and the second direction y coincide with the longitudinal direction of the margin portion 1Ab. In addition, no position measurement marks of the same form are formed in the intermediate portion of the margin portion 1Ab, that is, in the portion between adjacent unit pattern formation regions 1Aa, 1Aa. As a result, even if adjacent unit pattern formation regions 1Aa, 1Aa come closer together and the width of the margin portion 1Ab narrows, the position measurement marks 3A will not intrude into the unit pattern formation region 1Aa, and no unnecessary patterns will be formed in the unit pattern formation region 1Aa. Therefore, a photomask 1 can be provided in which the position measurement marks 3A are formed in a suitable form.

[0035] Furthermore, position measurement marks 3B are formed at appropriate locations on the outer edge region 1B. In other words, position measurement marks 3B are also formed near the reference mark (alignment mark 4) of the exposure device. By measuring the position of these marks 3B, the positional accuracy of the entire pattern can be confirmed.

[0036] <Mark for position measurement (1)> Here, the position measurement marks 3 (3A, 3B) according to Embodiment 1 will be described with reference to Figures 3 and 4.

[0037] As shown in Figure 3, the position measurement mark 3 is composed of 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 at their midpoint. As a result, the position measurement mark 3 has a + (plus) shape. In addition, the central part of the two lines 3a, 3a is cut out with the same width (Gx=Gy). As a result, the position measurement mark 3 has a hollow structure in which the intersection of the two lines 3a, 3a is cut out. The reason for this hollow structure is that when measured by a coordinate measuring device, the overlapping of the two lines 3a, 3a at the intersection would be conspicuous and undesirable for measurement.

[0038] The line widths Wx and Wy of line 3a are between 0.7 μm and 1.0 μm. This is a line width that can be read by a coordinate measuring device and is such that line 3a is not resolved on the panel during the exposure process using a photomask 1 (since it is for FPD, it is 1:1 projection exposure). The lengths Lx and Ly of line 3a are between 100 μm and 200 μm. This is a length that is easy for a coordinate measuring device to read. The gap widths Gx and Gy are between 10 μm and 20 μm. These are the same in embodiments 2 to 4 described below.

[0039] The position measurement marks 3 are formed on the transparent substrate 2. The transparent substrate 2 is a substrate such as synthetic quartz glass. The transparent substrate 2 has a transmittance of 95% or more to representative wavelengths (e.g., i-line, h-line, or g-line) contained 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 it may be a mixed light containing at least two of these lights. Alternatively, the wavelength band of the exposure light may be shifted or extended to the shorter wavelength side and / or the longer wavelength side with respect to these lights. As an example, the wavelength band of the exposure light can be extended from a broadband of 365nm to 436nm to 300nm to 450nm. However, the exposure light is not limited to these.

[0040] The position measurement mark 3 is composed of a light-shielding film 5. The light-shielding film 5 is made of a Cr-based material from 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 this 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 the representative wavelength included in the exposure light. Alternatively, the optical density (OD value) in the light-shielding portion should be 2.7 or higher. As an example, the light-shielding film 5 has a laminated structure comprising a first film-forming layer and a second film-forming layer. The first film-forming layer is composed of a Cr film and is intended for light shielding. The second film-forming layer is composed of a chromium oxide film and is intended for reflection suppression. In this case, even if the transmittance of the first film-forming layer is higher than 1%, it is sufficient if the combined transmittance of the first and second film-forming layers is 1% or less.

[0041] Next, a method for forming the position measurement marks 3 (3A, 3B) according to Embodiment 1 will be described.

[0042] This formation method is performed simultaneously in the manufacturing direction of the photomask 1. i) Photomask blank preparation process (Step 1) ii) Resist film formation process (Step 2) iii) Drawing process (process 3) iv) Development process (Step 4) v) Light-shielding film etching process (Step 5) vi) Resist film removal process (step 6) It is equipped with.

[0043] The process from the resist film formation process (step 2) to the resist film removal process (step 6) is called the patterning process. In the patterning process, position measurement marks 3 are patterned (simultaneously with the patterning of the unit pattern).

[0044] In the photomask blank preparation step (step 1), as shown in Figures 4(a-1) and (a-2), a photomask blank is prepared in which a light-shielding film 5 is formed on a transparent substrate 2. The light-shielding film 5 is formed by sputtering, vapor deposition, or the like.

[0045] In the resist film formation step (step 2), as shown in Figures 4(b-1) and (b-2), the resist is uniformly applied on the light-shielding film 5 to form a resist film 8. The resist is applied by coating or spraying.

[0046] In the drawing process (step 3), exposure light is irradiated onto the resist film 8 using an electron beam or laser of the drawing device, and a resist pattern corresponding to the position measurement marks 3 is drawn.

[0047] In the development step (step 4), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. Development is performed by immersion in a developing solution. The drawing step (step 3) and the development step (step 4) together are called the resist pattern formation step.

[0048] In the light-shielding film etching process (step 5), the resist pattern is used as an etching mask, and the exposed portions of the light-shielding film 5 are removed by etching. Etching can be done by either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. Etching is performed using an etching solution or etching gas.

[0049] In the resist film removal step (step 6), the resist film 8 is removed as shown in Figures 4(c-1) and (c-2). The resist film 8 is removed by ashing or by immersion in a resist stripping solution.

[0050] After going through steps 1 through 6 described above, the position measurement mark 3 is completed (along with the completion of photomask 1).

[0051] <Position measurement mark (2)> Next, the position measurement marks 3 (3A, 3B) according to Embodiment 2 will be described with reference to Figures 5 to 7.

[0052] As shown in Figure 5, the position measurement mark 3 is composed of 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 width and length and intersect each other at their midpoint. As a result, the position measurement mark 3 has a + (plus) shape. In addition, the central part of the two lines 3a, 3a is cut out by the same width. As a result, the position measurement mark 3 has a hollow structure in which the intersection of the two lines 3a, 3a is cut out. Furthermore, the two lines 3a, 3a are divided into an inner part 3b and an outer part 3c with a gap between them. The inner part 3b constitutes the first pattern of the position measurement mark 3. The outer part 3c constitutes the second pattern of the position measurement mark 3. As a result, the position measurement mark 3 is composed of a first pattern and a second pattern that are physically separated.

[0053] The inner portion 3b of the position measurement mark 3 is composed of a laminated film of a light-shielding film 5 and a semi-permeable film 6. The light-shielding film 5 and the semi-permeable film 6 are made of the same material, specifically a Cr-based material. In this embodiment, a Cr-based compound is used for both the light-shielding film 5 and the semi-permeable film 6. Alternatively, a non-Cr-based material may be used for the semi-permeable film 6. The semi-permeable film 6 is a phase-shift film. Alternatively, the semi-permeable film 6 may be a halftone film. The semi-permeable film 6 has a transmittance lower than that of the transparent substrate 2 and higher than that of the light-shielding film 5 with respect to a representative wavelength included in the exposure light, and is set to have a transmittance of 5% to 70% with respect to the representative wavelength. The semi-permeable film 6 may also be a semi-permeable metal film in which the transmittance distribution within the plane of the photomask 1 is improved by adjusting the nitrogen content. Furthermore, the optical density (OD value) in the semi-permeable portion of the semi-permeable film 6 can be changed by including other elements.

[0054] In the inner portion 3b of the position measurement mark 3, a semi-permeable film 6 is formed on top of the light-shielding film 5. The lines of the semi-permeable film 6 are formed to be slightly longer and slightly wider than the lines of the light-shielding film 5. As a result, both ends and both sides of the lines of the light-shielding film 5 are covered and protected by the semi-permeable film 6. In the inner portion 3b, a rim is formed around the periphery because the lines of the semi-permeable film 6 are slightly larger than the lines of the light-shielding film 5.

[0055] The outer portion 3c of the position measurement mark 3 is composed of the same semi-permeable film 6 as the uppermost layer of the inner portion 3b. In this embodiment, the outer portion 3c has the same shape as the lines of the light-shielding film 5 of the inner portion 3b.

[0056] In Figures 5 to 7, the light-shielding film 5 and the semi-transparent film 6 are depicted with the same thickness. However, this is for convenience only, and the actual thicknesses of the light-shielding film 5 and the semi-transparent film 6 can be set as appropriate.

[0057] Next, a method for forming the position measurement marks 3 (3A, 3B) according to Embodiment 2 will be described.

[0058] This formation method is performed simultaneously in the manufacturing direction of the photomask 1. i) Photomask blank preparation process (Step 1) ii) Resist film formation process (Step 2) iii) Drawing process (process 3) iv) Development process (Step 4) v) Light-shielding film etching process (Step 5) vi) Resist film removal process (step 6) vii) Semi-permeable membrane formation process (Step 7) viii) Resist film formation process (step 8) ix) Drawing process (process 9) x) Development process (Step 10) xi) Semipermeable film etching process (Step 11) xii) Resist film removal process (step 12) It is equipped with.

[0059] The resist film formation process (step 2) to the resist film removal process (step 6) is referred to as the first patterning process, and the resist film formation process (step 8) to the resist film removal process (step 12) is referred to as the second patterning process. In the first patterning process, 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 process, the first and second patterns of the position measurement mark 3 are patterned (simultaneously with the second patterning of the unit pattern).

[0060] In the photomask blank preparation step (step 1), as shown in Figures 6(a-1) and (a-2), a photomask blank is prepared in which a light-shielding film 5 is formed on a transparent substrate 2. The light-shielding film 5 is formed by sputtering, vapor deposition, or the like.

[0061] In the first resist film formation step (step 2), as shown in Figures 6(b-1) and (b-2), the resist is uniformly applied on the light-shielding film 5 to form the resist film 8. The resist is applied by coating or spraying.

[0062] In the first drawing process (step 3), exposure light is irradiated onto the resist film 8 using the electron beam or laser of the drawing device, and a resist pattern corresponding to the inner portion 3b of the position measurement mark 3 is drawn.

[0063] In the first development step (step 4), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. Development is performed by immersion in a developer solution. The first drawing step (step 3) and the first development step (step 4) together are referred to as the first resist pattern formation step.

[0064] In the light-shielding film etching process (step 5), the resist pattern is used as an etching mask, and the exposed portions of the light-shielding film 5 are removed by etching. Etching can be done by either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. Etching is performed using an etching solution or etching gas.

[0065] In the first resist film removal step (step 6), the resist film 8 is removed as shown in Figures 6(c-1) and (c-2). The resist film 8 is removed by ashing or by immersion in a resist stripping solution.

[0066] In the semipermeable film formation step (step 7), as shown in Figures 7(a-1) and (a-2), a semipermeable film 6 is formed on the exposed portion of the transparent substrate 2 from which the light-shielding film 5 has been removed and on the light-shielding film 5. The semipermeable film 6 is formed by sputtering, vapor deposition, or the like.

[0067] In the second resist film formation step (step 8), as shown in Figures 7(b-1) and (b-2), the resist is uniformly applied to the semipermeable film 6 to form the resist film 8. The resist is applied by coating or spraying.

[0068] In the second drawing process (step 9), exposure light is irradiated onto the resist film 8 using an electron beam or laser from the drawing apparatus, and resist patterns corresponding to the inner portion 3b and outer portion 3c of the position measurement mark 3 are drawn. Here, the resist pattern corresponding to the inner portion 3b is set to be slightly longer and slightly wider than the resist pattern corresponding to the inner portion 3b in the first drawing process (step 3).

[0069] In the second development step (step 10), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. Development is performed by immersion in a developer solution. The second drawing step (step 9) and the second development step (step 10) together are referred to as the second resist pattern formation step.

[0070] In the semipermeable film etching process (step 11), the resist pattern is used as an etching mask, and the exposed portions of the semipermeable film 6 are removed by etching. Etching can be done by either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. Etching is performed using an etching solution or etching gas. At this time, the light-shielding film 5 is protected by the semipermeable film 6 and is not etched.

[0071] In the second resist film removal step (step 12), the resist film 8 is removed as shown in Figures 7(c-1) and (c-2). The resist film 8 is removed by ashing or by immersion in a resist stripping solution.

[0072] After going through steps 1 to 12 described above, the position measurement mark 3 is completed (along with the completion of photomask 1).

[0073] Thus, the position measurement mark 3 is formed in two separate patterning steps: a first patterning step and a second patterning step. More specifically, the inner portion 3b (first pattern) of the position measurement mark 3 is formed by the first and second patterning steps, while the outer portion 3c (second pattern) of the position measurement mark 3 is formed by the second patterning step. Therefore, if an alignment error occurs between the first and second patterning steps, the inner portion 3b and the outer portion 3c will be formed with a misalignment. For this reason, the alignment accuracy of the photomask 1 can be confirmed by inspecting the position measurement mark 3.

[0074] <Position measurement mark (3)> Next, the position measurement marks 3 (3A, 3B) according to Embodiment 3 will be described with reference to Figures 8 to 10.

[0075] As shown in Figure 8, the position measurement mark 3 is composed of 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 width and length and intersect each other at their midpoint. As a result, the position measurement mark 3 has a + (plus) shape. In addition, the central part of the two lines 3a, 3a is cut out by the same width. As a result, the position measurement mark 3 has a hollow structure in which the intersection of the two lines 3a, 3a is cut out. Furthermore, the two lines 3a, 3a are divided into an inner part 3b and an outer part 3c with a gap between them. The inner part 3b constitutes the first pattern of the position measurement mark 3. The outer part 3c constitutes the second pattern of the position measurement mark 3. As a result, the position measurement mark 3 is composed of a first pattern and a second pattern that are physically separated.

[0076] The inner portion 3b of the position measurement mark 3 is composed of a laminated film consisting of a semipermeable film 6, an interlayer (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 a Cr-based material. In this embodiment, the light-shielding film 5 and the semipermeable film 6 are made of a Cr-based compound. The interlayer 7 is made of a non-Cr-based material. In this embodiment, the interlayer 7 is made of Ni, Ti, or a molybdenum silicide compound. Alternatively, the light-shielding film 5 and the semipermeable film 6 may be made of a non-Cr-based material, and the interlayer 7 may be made of a Cr-based material.

[0077] The light-shielding film 5 and the semi-permeable film 6 have the same etching properties because they are made of the same material. However, the light-shielding film 5 and the semi-permeable film 6 have different etching properties from the interlayer film 7 because they are made of different materials. That is, the light-shielding film 5 and the semi-permeable film 6 have etching selectivity with respect to the interlayer film 7, and the interlayer film 7 has etching selectivity with respect to the light-shielding film 5 and the semi-permeable film 6.

[0078] In the inner portion 3b of the position measurement mark 3, an interlayer 7 is formed on the semipermeable film 6, and a light-shielding film 5 is formed on the interlayer 7. The lines of the semipermeable film 6 are formed to be slightly longer and slightly wider than the lines of the light-shielding film 5 and the interlayer 7. As a result, the semipermeable film 6 protrudes from both ends and sides of the lines of the light-shielding film 5 and the interlayer 7. In the inner portion 3b, a rim is formed at the periphery because the lines of the semipermeable film 6 are slightly larger than the lines of the light-shielding film 5 and the interlayer 7.

[0079] The outer portion 3c of the position measurement mark 3 is composed of the same semipermeable film 6 as the bottom layer of the inner portion 3b. In this embodiment, the outer portion 3c has the same shape as the lines of the light-shielding film 5 and the interlayer film 7 of the inner portion 3b.

[0080] In Figures 8 to 10, the semipermeable film 6, the interlayer 7, and the light-shielding film 5 are depicted with the same thickness. However, this is for convenience only, and the actual thicknesses of the semipermeable film 6, the interlayer 7, and the light-shielding film 5 can be set as appropriate.

[0081] Next, a method for forming the position measurement marks 3 (3A, 3B) according to Embodiment 3 will be described.

[0082] This formation method is performed simultaneously in the manufacturing direction of the photomask 1. i) Photomask blank preparation process (Step 1) ii) Resist film formation process (Step 2) iii) Drawing process (process 3) iv) Development process (Step 4) v) Light-shielding film etching process (Step 5) vi) Resist film removal process (step 6) vii) Interlayer etching process (step 7) viii) Resist film formation process (step 8) ix) Drawing process (process 9) x) Development process (Step 10) xi) Semipermeable film etching process (Step 11) xii) Resist film removal process (step 12) It is equipped with.

[0083] The resist film formation process (step 2) to the resist film removal process (step 6) is referred to as the first patterning process, and the resist film formation process (step 8) to the resist film removal process (step 12) is referred to as the second patterning process. In the first patterning process, 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 process, the first and second patterns of the position measurement mark 3 are patterned (simultaneously with the second patterning of the unit pattern).

[0084] In the photomask blank preparation process (step 1), as shown in Figures 9(a-1) and (a-2), a photomask blank is prepared in which a semi-permeable film 6 is formed on a transparent substrate 2, an interlayer 7 is formed on the semi-permeable film 6, and a light-shielding film 5 is formed on the interlayer 7. The semi-permeable film 6, interlayer 7, and light-shielding film 5 are formed by sputtering, vapor deposition, or the like, respectively.

[0085] In the first resist film formation step (step 2), as shown in Figures 9(b-1) and (b-2), the resist is uniformly applied on the light-shielding film 5 to form the resist film 8. The resist is applied by coating or spraying.

[0086] In the first drawing process (step 3), exposure light is irradiated onto the resist film 8 using the electron beam or laser of the drawing device, and a resist pattern corresponding to the inner portion 3b of the position measurement mark 3 is drawn.

[0087] In the first development step (step 4), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. Development is performed by immersion in a developer solution. The first drawing step (step 3) and the first development step (step 4) together are referred to as the first resist pattern formation step.

[0088] In the light-shielding film etching process (step 5), the resist pattern is used as an etching mask, and the exposed portions of the light-shielding film 5 are removed by etching. Etching can be done by either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. Etching solutions or etching gases are used. In any case, an etchant that has etching selectivity for the light-shielding film 5 (an etchant that does not etch the interlayer film 7) is used.

[0089] In the first resist film removal step (step 6), the resist film 8 is removed as shown in Figures 9(c-1) and (c-2). The resist film 8 is removed by ashing or by immersion in a resist stripping solution.

[0090] In the interlayer etching process (step 7), as shown in Figures 10(a-1) and (a-2), the light-shielding film 5 is used as an etching mask, and the exposed portions of the interlayer 7 are removed by etching. Etching can be either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. Etching solutions or etching gases are used. In any case, an etchant that has etching selectivity for the interlayer 7 (an etchant that does not etch the light-shielding film 5 and the semi-transparent film 6) is used.

[0091] In the second resist film formation step (step 8), as shown in Figures 10(b-1) and (b-2), the resist is uniformly applied to the light-shielding film 5 and the semi-transparent film 6 to form the resist film 8. The resist is applied by coating or spraying.

[0092] In the second drawing process (step 9), exposure light is irradiated onto the resist film 8 using an electron beam or laser from the drawing apparatus, and resist patterns corresponding to the inner portion 3b and outer portion 3c of the position measurement mark 3 are drawn. Here, the resist pattern corresponding to the inner portion 3b is set to be slightly longer and slightly wider than the resist pattern corresponding to the inner portion 3b in the first drawing process (step 3).

[0093] In the second development step (step 10), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. Development is performed by immersion in a developer solution. The second drawing step (step 9) and the second development step (step 10) together are referred to as the second resist pattern formation step.

[0094] In the semipermeable film etching process (step 11), the resist pattern is used as an etching mask, and the exposed portions of the semipermeable film 6 are removed by etching. Etching can be either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. Etching solutions or etching gases are used. In any case, an etchant that has etching selectivity for the semipermeable film 6 (an etchant that does not etch the interlayer 7) is used. However, the interlayer 7 is protected by the resist and is not etched in the first place. Similarly, the light-shielding film 5 is also protected by the resist and is not etched.

[0095] In the second resist film removal step (step 12), the resist film 8 is removed as shown in Figures 10(c-1) and (c-2). The resist film 8 is removed by ashing or by immersion in a resist stripping solution.

[0096] After going through steps 1 to 12 described above, the position measurement mark 3 is completed (along with the completion of photomask 1).

[0097] Thus, the position measurement mark 3 is formed in two separate patterning steps: a first patterning step and a second patterning step. More specifically, the inner portion 3b (first pattern) of the position measurement mark 3 is formed by the first and second patterning steps, while the outer portion 3c (second pattern) of the position measurement mark 3 is formed by the second patterning step. Therefore, if an alignment error occurs between the first and second patterning steps, the inner portion 3b and the outer portion 3c will be formed with a misalignment. For this reason, the alignment accuracy of the photomask 1 can be confirmed by inspecting the position measurement mark 3.

[0098] <Mark for position measurement (4)> Next, the position measurement marks 3 (3A, 3B) according to Embodiment 4 will be described with reference to Figures 11 to 13.

[0099] As shown in Figure 11, the position measurement mark 3 is composed of 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 length and intersect each other at their midpoint. As a result, the position measurement mark 3 has a + (plus) shape. In addition, the central part of the two lines 3a, 3a is cut out by the same width. As a result, the position measurement mark 3 has a hollow structure in which the intersection of the two lines 3a, 3a is cut out. Furthermore, the two lines 3a, 3a are divided into an inner part 3b and an outer part 3c with a gap in between. The inner part 3b constitutes the first pattern of the position measurement mark 3. The outer part 3c constitutes the second pattern of the position measurement mark 3. As a result, the position measurement mark 3 is composed of a first pattern and a second pattern that are physically separated.

[0100] 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 a Cr-based material. In this embodiment, the light-shielding film 5 is made of a Cr-based compound. The semipermeable film 6 is made of a non-Cr-based material. In this embodiment, the semipermeable film 6 is made of Ni, Ti, or a molybdenum silicide compound. Alternatively, the light-shielding film 5 may be made of a non-Cr-based material, and the semipermeable film 6 may be made of a Cr-based material.

[0101] The light-shielding film 5 and the semi-permeable film 6 have different etching properties due to their different materials. Specifically, the light-shielding film 5 exhibits etching selectivity relative to the semi-permeable film 6, and the semi-permeable film 6 exhibits etching selectivity relative to the light-shielding film 5.

[0102] In the inner portion 3b of the position measurement mark 3, a light-shielding film 5 is formed on the semi-permeable film 6. The lines of the light-shielding film 5 have the same shape as the lines of the semi-permeable film 6.

[0103] The outer portion 3c of the position measurement mark 3 is composed of the same semipermeable membrane 6 as the bottom layer of the inner portion 3b. In this embodiment, the outer portion 3c has the same shape as the inner portion 3b.

[0104] Note that in Figures 11 to 13, the semipermeable film 6 and the light-shielding film 5 are depicted with the same thickness. However, this is for convenience only, and the actual thicknesses of the semipermeable film 6 and the light-shielding film 5 can be set as appropriate.

[0105] Next, a method for forming the position measurement marks 3 (3A, 3B) according to Embodiment 4 will be described.

[0106] This formation method is performed simultaneously in the manufacturing direction of the photomask 1. i) Photomask blank preparation process (Step 1) ii) Resist film formation process (Step 2) iii) Drawing process (process 3) iv) Development process (Step 4) v) Light-shielding film etching process (Step 5) vi) Resist film removal process (step 6) vii) Resist film formation process (Step 7) viii) Drawing process (process 8) ix) Development process (Step 9) x) Semipermeable film etching process (step 10) xi) Resist film removal process (step 11) It is equipped with.

[0107] The resist film formation process (step 2) to the resist film removal process (step 6) is called the first patterning process, and the resist film formation process (step 7) to the resist film removal process (step 11) is called the second patterning process. In the first patterning process, 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 process, the second pattern of the position measurement mark 3 is patterned (simultaneously with the second patterning of the unit pattern).

[0108] In the photomask blank preparation process (step 1), as shown in Figures 12(a-1) and (a-2), a photomask blank is prepared in which a semi-permeable film 6 is formed on a transparent substrate 2, and a light-shielding film 5 is formed on the semi-permeable film 6. The semi-permeable film 6 and the light-shielding film 5 are formed by sputtering, vapor deposition, or the like, respectively.

[0109] In the first resist film formation step (step 2), as shown in Figures 12(b-1) and (b-2), the resist is uniformly applied on the light-shielding film 5 to form the resist film 8. The resist is applied by coating or spraying.

[0110] In the first drawing process (step 3), exposure light is irradiated onto the resist film 8 using the electron beam or laser of the drawing device, and a resist pattern corresponding to the inner portion 3b of the position measurement mark 3 is drawn.

[0111] In the first development step (step 4), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. Development is performed by immersion in a developer solution. The first drawing step (step 3) and the first development step (step 4) together are referred to as the first resist pattern formation step.

[0112] In the light-shielding film etching process (step 5), the resist pattern is used as an etching mask, and the exposed portions of the light-shielding film 5 are removed by etching. Etching can be done by either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. Etching solutions or etching gases are used. In any case, an etchant that has etching selectivity for the light-shielding film 5 (an etchant that does not etch the semi-permeable film 6) is used.

[0113] In the first resist film removal step (step 6), the resist film 8 is removed as shown in Figures 12(c-1) and (c-2). The resist film 8 is removed by ashing or by immersion in a resist stripping solution.

[0114] In the second resist film formation step (step 7), as shown in Figures 13(a-1) and (a-2), the resist is uniformly applied to the light-shielding film 5 and the semi-transparent film 6 to form the resist film 8. The resist is applied by coating or spraying.

[0115] In the second drawing process (step 8), exposure light is irradiated onto the resist film 8 using the electron beam or laser of the drawing device, and a resist pattern corresponding to the outer portion 3c of the position measurement mark 3 is drawn.

[0116] In the second development step (step 9), the unnecessary resist film 8 is removed by development, and a resist pattern is formed. Development is performed by immersion in a developer solution. The second drawing step (step 8) and the second development step (step 9) together are referred to as the second resist pattern formation step.

[0117] In the semipermeable film etching process (step 10), the resist pattern is used as an etching mask, and the exposed portions of the semipermeable film 6 are removed by etching. Etching can be either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. Etching solutions or etching gases are used. In any case, an etchant that has etching selectivity for the semipermeable film 6 (an etchant that does not etch the light-shielding film 5) is used.

[0118] In the second resist film removal step (step 11), the resist film 8 is removed as shown in Figures 13(b-1) and (b-2). The resist film 8 is removed by ashing or by immersion in a resist stripping solution.

[0119] After going through steps 1 through 11 described above, the position measurement mark 3 is completed (along with the completion of photomask 1).

[0120] Thus, the position measurement mark 3 is formed in two separate patterning steps: a first patterning step and a second patterning step. More specifically, the inner portion 3b (first pattern) of the position measurement mark 3 is formed by the first patterning step, and the outer portion 3c (second pattern) of the position measurement mark 3 is formed by the second patterning step. Therefore, if an alignment error occurs between the first and second patterning steps, the inner portion 3b and the outer portion 3c will be formed with a misalignment. For this reason, the alignment accuracy of the photomask 1 can be confirmed by inspecting the position measurement mark 3.

[0121] <Application Example (Manufacturing Method for Photomasks for FPDs Composed of Multiple Layers)> In conventional manufacturing methods for FPD photomasks, which consist of multiple photomasks as a set, with each photomask forming a layer, the patterning process is performed based on drawing data from CAD data described using the reference coordinates, after a reference coordinate has been set in the drawing device. As a result, the position measurement of each photomask shows an error relative to the reference coordinates. Furthermore, the drawing device and coordinate measuring device have a certain degree of measurement error. Consequently, the overlay error becomes larger depending on the positional deviation of the reference layer and the overlay layer relative to the reference coordinates.

[0122] Therefore, a manufacturing method is employed in which the amount of displacement and the displacement angle are determined from the position measurement results (see Figure 15(a)) of the position measurement marks on the previously manufactured photomask (reference mask which serves as the reference layer), the coordinate values ​​of the drawing data are transformed using these values ​​to correct the drawing data, and the patterning process is performed based on this corrected drawing data. Referring to Figure 15(b), first, for the reference mask, the patterning process is performed as usual based on the drawing data described using reference coordinates. After the manufacturing of the reference mask, the position measurement marks on the reference mask are measured, and from these position measurement results, the amount of displacement Δx in the first direction x, the amount of displacement Δy in the second direction y, and the displacement angle θ are determined. Then, the drawing data of the second and subsequent photomasks are transformed and corrected using the values ​​of Δx, Δy, and θ, respectively. Then, for the second and subsequent photomasks, the patterning process is performed based on the corrected drawing data.

[0123] Thus, according to the method for manufacturing a photomask for an FPD as described in the application example, the result of drawing the reference layer becomes the reference coordinate of the superimposed layer, and the superposition error between the reference layer and the superimposed layer can be minimized. For this reason, the method for manufacturing a photomask for an FPD as described in the application example can improve the superposition accuracy of the reference layer and the superimposed layer. In other words, the method for manufacturing a photomask for an FPD as described in the application example is a technology that pursues the superposition accuracy of each layer while allowing for positional misalignment, and is a technology that is superior in terms of delivery time and cost compared to correcting the drawing data and remanufacturing the reference mask.

[0124] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0125] In embodiments 1 to 4 described above, the position measurement mark 3 has a hollow structure in which the intersection of the two lines 3a, 3a is cut away. However, the present invention is not limited thereto. The position measurement mark may also be in a form in which the intersection of the two lines is not cut away and they overlap.

[0126] Furthermore, in embodiments 1 to 4 described above, the position measurement mark 3 has a plus (+) shape because two orthogonal lines 3a, 3a intersect at their midpoints. However, the present invention is not limited thereto. For example, the position measurement mark may have an L shape because two orthogonal lines intersect at their endpoints, or it may have a T shape because two orthogonal lines intersect at their midpoints and the other at their endpoints. Of course, in these cases as well, whether or not the intersection of the two lines is cut off can be appropriately set.

[0127] Furthermore, in embodiments 1 to 4 described above, the two lines 3a, 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 mark may have some angle with respect to the first direction x and the second direction y. The phrases "along the first direction" and "along the second direction" include such configurations.

[0128] Furthermore, in embodiments 1 to 4 described above, the position measurement marks 3A are formed only in the portion where the margins 1Ab intersect within the pattern formation region 1A. However, the present invention is not limited thereto. As shown in Figure 14, if the position measurement marks 3C have a shorter length Lx on one of the lines 3a and do not intrude into the unit pattern formation region 1Aa, they may be formed in the intermediate portion of the margins 1Ab, that is, in the portion between adjacent unit pattern formation regions 1Aa, 1Aa.

[0129] Furthermore, in Embodiment 1 above, a photomask blank with a light-shielding film 5 formed on a transparent substrate 2 is used. In Embodiment 2 above, a photomask blank with a light-shielding film 5 formed on a transparent substrate 2 is used, and after the first patterning step, a semi-permeable film 6 is laminated and formed. In Embodiment 3 above, a photomask blank is used in which a semi-permeable film 6 is formed on a transparent substrate 2, an interlayer 7 is formed on the semi-permeable film 6, and a light-shielding film 5 is formed on the interlayer 7. In Embodiment 4 above, a photomask blank is used in which a semi-permeable film 6 is formed on a transparent substrate 2, and a light-shielding film 5 is formed on the semi-permeable film 6. However, the present invention is not limited to these. In these, the light-shielding film and the semi-permeable film can be interchanged. In addition, other functional films other than the light-shielding film and semi-permeable film may be used.

[0130] Furthermore, in embodiments 1 to 4 described above, it is assumed that the position measurement mark 3A is formed in the pattern formation region 1A at the point where the margin portion 1Ab intersects. However, in the method for forming a position measurement mark in a photomask for an FPD according to the present invention, with embodiments 2 to 4 described above as embodiments, the location where the position measurement mark is formed is not particularly limited. The method for forming a position measurement mark in a photomask for an FPD according to the present invention can be established as a novel and innovative elemental technology invention regardless of the location where the position measurement mark is formed.

[0131] Furthermore, in embodiments 1 to 4 described above, 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 constitute the first pattern, and the inner portion may constitute the second pattern.

[0132] Furthermore, in embodiments 1 to 4 described above, the first pattern and the second pattern are obtained by dividing the position measurement mark 3 into an inner region and an outer region. However, the present invention is not limited thereto. For example, the division of the first pattern and the second pattern can be set as appropriate, such as one line of the position measurement mark constituting the first pattern and the other line constituting the second pattern. [Industrial applicability]

[0133] The photomask according to the present invention can be exposed using an exposure apparatus known for use with flat panel displays (FPDs). For example, as the exposure apparatus, a 1:1 projection exposure apparatus can be used that uses exposure light from a single-wavelength or broadband light source with a peak at 300-500 nm, has a numerical aperture (NA) of around 0.09 (0.07-0.12), and has a 1:1 optical system with a coherence factor (σ) of a conventionally known degree. Note that it is also applicable even if the numerical aperture is 0.12 or higher. Of course, the photomask according to the present invention can also be used as a photomask for proximity exposure. [Explanation of symbols]

[0134] 1...Photomask, 1A...Pattern formation area, 1Aa...Unit pattern formation area, 1Ab...Margin area, 1B...Outer edge area, 2...Transparent substrate, 3,3A~3C...Position measurement marks, 3a...Line, 3b...Inner part, 3c...Outer part, 4...Alignment marks, 5...Light-shielding film, 6...Semi-transparent film, 7...Interlayer film (etching stopper film), 8...Resist film, Wx,Wy...Line width, Lx,Ly...Line length, Gx,Gy...Gap width, Δx...Deviation amount in the first direction x, Δy...Deviation amount in the second direction y, θ...Deviation angle

Claims

1. A photomask for an FPD, comprising: a pattern formation region in which a plurality of unit pattern formation regions are two-dimensionally arranged along a first direction and a second direction perpendicular to each other and have margins around the periphery, an outer edge region surrounding the pattern formation region, and a plurality of position measurement marks, The position measurement marks are configured by a combination of lines along a first direction and lines along a second direction, and are formed only at portions where the margins intersect in the pattern formation region. Photomasks for FPDs.

2. The position measurement mark has a form in which a line along a first direction and a line along a second direction intersect, and is arranged in the pattern formation region so that the intersection of the two lines coincides with the intersection of the center lines of the margin portion. The photomask for FPD according to claim 1 .

3. The position measurement mark has a shape in which a line along a first direction and a line along a second direction intersect, and is formed separately into an inner portion and an outer portion.

3. The photomask for FPD according to claim 1 or 2.

4. 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, and the other of the inner portion and the outer portion is composed of the first functional film or the second functional film. The photomask for FPD according to claim 3 .

5. The position measurement mark has a shape in which a line along a first direction and a line along a second direction intersect, and the intersection of the two lines is cut off.

5. The photomask for FPD according to claim 1.

6. The position measurement marks are also formed in the outer edge region.

6. The photomask for FPD according to claim 1.

7. The alignment mark is provided in the outer edge region and is composed of lines having a line width greater than the line width of the line constituting the position measurement mark.

7. The photomask for FPD according to claim 1.

8. Dividing the position measurement mark into a first pattern and a second pattern; forming a first pattern by a first patterning step and a second patterning step, or by a first patterning step; A second pattern is formed by a second patterning process. A method for forming a position measurement mark on a photomask for an FPD.

9. A first patterning step is performed 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 then a second patterning step is performed.

9. A method for forming a position measurement mark on a photomask for an FPD according to claim 8.

10. a first patterning step is performed on a photomask blank having a first functional film formed on a transparent substrate, an intermediate film having an etching characteristic different from that of the first functional film formed on the first functional film, and a second functional film having the same etching characteristic as that of the first functional film formed on the intermediate film; After the first patterning step, the intermediate film is removed by etching, and then the second patterning step is performed.

9. A method for forming a position measurement mark on a photomask for an FPD according to claim 8.

11. a first patterning step is performed on a photomask blank in which a first functional film is formed on a transparent substrate and a second functional film having etching characteristics different from those of the first functional film is formed on the first functional film; After the first patterning step, a second patterning step is performed.

9. A method for forming a position measurement mark on a photomask for an FPD according to claim 8.

12. A method for manufacturing a second or subsequent photomask of a photomask for an FPD, the photomask being configured with a plurality of layers, each of which is one layer and including a plurality of photomasks as one set, comprising the steps of: The amount and angle of deviation in a first direction and a second direction perpendicular to each other are obtained from the position measurement result of the position measurement mark provided on the first photomask previously manufactured, and the coordinate values ​​of the drawing data are converted using these values ​​to correct the drawing data, and a patterning process is performed based on this corrected drawing data. A method for manufacturing a photomask for FPD.

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