Photomask for FPD, method for forming position measurement mark on photomask for FPD, and method for manufacturing 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 on a photomask for an FPD, and a method for manufacturing a photomask for an FPD. [Background technology]

[0002] The displays of small information devices such as mobile phones, smartphones, mobile PCs, and tablets are mainly flat panel displays (FPDs), which use small panels such as liquid crystal displays, plasma displays, and organic light-emitting diode (OLED) displays.

[0003] Panel production uses photolithography technology, which forms patterns on a transparent substrate by exposing a photomask pattern onto the transparent substrate coated with a photosensitive material. In the case of small panels, in order to improve productivity, a large photomask is used in which multiple unit patterns, each corresponding to one small panel, are arranged two-dimensionally, and multiple small panels are produced simultaneously.

[0004] This photomask has a pattern formation area and an outer edge area. The pattern formation area is an area that includes all unit patterns. The outer edge area is an area that surrounds the pattern formation area. Position measurement marks are formed in the outer edge area. Conventionally, the positional accuracy of the unit patterns has been guaranteed by measuring the positions of the position measurement marks in the outer edge area.

[0005] However, the distance between each unit pattern and the position measurement mark is not the same, but varies depending on the position of each unit pattern. Furthermore, errors that occur in the photomask manufacturing process (mainly the resist pattern writing process) can sometimes cause local pattern misalignment within the pattern formation area. For this reason, conventional assurance methods suffer from a lack of accuracy.

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

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-201844 Summary of the Invention [Problem to be solved by the invention]

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

[0009] The present invention has been made in view of the above circumstances, and has as its object to provide a photomask for FPDs on which position measurement marks are formed in a suitable form.

[0010] Additionally, an object of the present invention is to provide a method for forming position measurement marks on a photomask for FPD, which is capable of forming position measurement marks of a suitable form.

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

[0012] The photomask for FPD according to the present invention comprises: 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 orthogonal 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 in portions where margins intersect in the pattern formation region. 、 The position measurement mark has a shape in which a line extending in a first direction and a line extending in a second direction intersect, and is formed by dividing it into an inner portion and an outer portion. This is a photomask for FPD. in this case, 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 either the first functional film or the second functional film. The functional film is a film having a function of adjusting the optical properties of the exposure light. Examples of the functional film include a phase shift film having a function of changing the phase of the exposure light, a semi-transparent film having a function of adjusting the transmittance of the exposure light, and a light-shielding film having a function of blocking the exposure light. Furthermore, the photomask for FPD according to the present invention comprises: 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 orthogonal 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 extending along a first direction and lines extending along a second direction, and are formed only in portions where margins intersect in the pattern formation region; The outer edge region is provided with a positioning mark that is made up of lines with a line width wider than the line width of the line that makes up the position measurement mark. This is a photomask for FPD.

[0013] Here, as one embodiment of the photomask for FPD according to the present invention, The position measurement mark has a form in which a line extending in a first direction and a line extending in 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 marginal portion. The above configuration can be adopted.

[0014] Also, As another aspect of the photomask for FPD according to the present invention, The position measurement mark has a shape in which a line extending in a first direction and a line extending in a second direction intersect, and the intersection of the two lines is cut out. The configuration can be adopted. 。

[0015] In addition, as another aspect of the photomask for FPD according to the present invention, The position measurement marks are also formed in the outer edge area. The above configuration can be adopted.

[0016] Further, a method for forming a position measurement mark on a photomask for an FPD according to the present invention includes the steps of: One of the inner part and the outer part of the position measurement mark is defined as a first pattern, and the other of the inner part and the outer part is defined as a second pattern, Dividing the position measurement marks 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 step. This is a method for forming a position measurement mark on a photomask for an FPD.

[0017] Here, as one aspect of the method for forming a position measurement mark on a photomask for FPD according to the present invention, 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 formed and then a second patterning step is performed. The above configuration can be adopted.

[0018] In addition, as another aspect of the method for forming a position measurement mark on a photomask for FPD according to the present invention, a first patterning step is performed on a photomask blank having a first functional film formed on a transparent substrate, an intermediate film having etching characteristics different from those of the first functional film formed on the first functional film, and a second functional film having etching characteristics identical to those 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. The above configuration can be adopted.

[0019] In addition, as another aspect of the method for forming a position measurement mark on a photomask for FPD according to the present invention, 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, the second patterning step is performed. The above configuration can be adopted.

[0020] Further, the method for manufacturing a photomask for an FPD according to the present invention comprises the steps of: A method for manufacturing a second or subsequent photomask of a photomask for FPD, which is configured with multiple layers, each of which is one layer and includes multiple photomasks as one set, comprising the steps of: The amount and angle of deviation in the first and second directions that are orthogonal to each other are determined from the position measurement results of the position measurement marks provided on the first photomask that was 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. This is a method for manufacturing photomasks for FPDs. [Effects of the Invention]

[0021] According to the FPD photomask of the present invention, the position measurement marks are made up of a combination of lines along the first direction and lines along the second direction, and are formed only in portions of the pattern formation region where margins intersect. This prevents the position measurement marks from encroaching on the unit pattern formation regions, and prevents unnecessary patterns from being formed in the unit pattern formation regions. Therefore, the FPD photomask of the present invention can provide an FPD photomask in which the position measurement marks are formed in a suitable form.

[0022] Furthermore, according to the method for forming position measurement marks on a photomask for FPD of the present invention, the alignment accuracy of the photomask can be confirmed by inspecting the position measurement marks formed in the first patterning process and the second patterning process. Therefore, according to the method for forming position measurement marks on a photomask for FPD of the present invention, it is possible to provide a position measurement mark of a suitable form.

[0023] Furthermore, according to the method for manufacturing a photomask for FPD of the present invention, in a photomask for FPD that is configured with multiple layers, with multiple photomasks forming one set and each photomask being one layer, it is possible to minimize the overlay error of each layer. Therefore, according to the method for manufacturing a photomask for FPD of the present invention, it is possible to improve the overlay accuracy of each layer when the photomask is configured with multiple layers. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic plan view of a photomask according to this embodiment. [Figure 2] Fig. 2(a) is an explanatory diagram of an example of the position measurement result of the position measurement mark, and Fig. 2(b) is an explanatory diagram of another example of the position measurement result of the position measurement mark. [Figure 3] Fig. 3(a) is a plan view of the position measurement mark according to embodiment 1. Fig. 3(b) is a cross-sectional view taken along line AA in Fig. 3(a). [Figure 4] FIG. 4 is an explanatory diagram of a method for forming marks for position measurement according to the first embodiment. [Figure 5] Fig. 5(a) is a plan view of a mark for position measurement according to embodiment 2. Fig. 5(b) is a cross-sectional view taken along line BB in Fig. 5(a). [Figure 6] FIG. 6 is an explanatory diagram of a method for forming marks for position measurement according to the second embodiment. [Figure 7] FIG. 7 is a continuation of FIG. [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 continued 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 continued 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 the photomask for FPD according to the present invention will be described with reference to Figs. 1 and 2. Note that an actual photomask for 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 with respect to the entire photomask 1, the number of rows and the total number of the matrix, etc. for easy understanding.

[0026] As shown in FIG. 1, the photomask 1 is generally rectangular, and includes a pattern formation region 1A and an outer edge region 1B on a transparent substrate 2. The pattern formation region 1A is rectangular. In the pattern formation region 1A, a plurality of unit pattern formation regions 1Aa, ... each corresponding to one small panel, are arranged two-dimensionally along a first direction x and a second direction y that are orthogonal to each other, with margins 1Ab around them. The unit pattern formation regions 1Aa are also rectangular. The margins 1Ab are in the form of a grid with a predetermined width, and serve as cutting regions for the panel. The outer edge region 1B is an area that surrounds the pattern formation region 1A.

[0027] In the pattern formation region 1A, position measurement marks 3A are formed at the portions where marginal portions 1Ab intersect. Furthermore, in the outer edge region 1B, position measurement marks 3B are formed in frame-shaped regions along the rectangular partition lines of the pattern formation region 1A. The position measurement marks 3B correspond to conventional position measurement marks and complement the position measurement marks 3A. In this embodiment, the position measurement marks 3B are formed at four corners and along two opposing sides of the partition lines. The position measurement marks 3 (3A, 3B) are read by a coordinate measurement device and are used to ensure the positional accuracy of each unit pattern that is two-dimensionally arranged. The position measurement marks 3 are formed during pattern formation of the pattern formation region 1A. That is, the formation of the unit patterns in the pattern formation region 1A and the formation of the position measurement marks 3 are performed simultaneously in the patterning process.

[0028] The position measurement mark 3 is made up of a combination of lines extending in the first direction x and lines extending in the second direction y. As an example, the position measurement mark 3 has a + (plus) shape formed by lines of the same length intersecting each other 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 tool and are used to set the photomask 1 in the appropriate position in the exposure tool. The alignment marks 4 are formed when the pattern is formed in the pattern formation region 1A. In other words, the formation of the unit patterns 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 lines extending in the first direction x and lines extending in the second direction y. As an example, the alignment mark 4 has a + (plus) shape, with lines of the same length intersecting each other at their midpoints. However, because the reading device included in the exposure apparatus has a lower resolution than the coordinate measurement device, the line width of the lines that make up the alignment mark 4 is thicker than the line width of the lines that make up the position measurement mark 3.

[0031] The positional accuracy of each unit pattern can be confirmed by measuring the position of position measurement mark 3A located nearby. FIG. 2(a) shows that position measurement mark 3A has shifted counterclockwise from its original position (represented by the intersection of the dashed lines), that is, each unit pattern has shifted counterclockwise. FIG. 2(b) shows that position measurement mark 3A has shifted clockwise from its original position, that is, 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 pattern formation area 1A.

[0032] If the positional misalignment of position measurement marks 3A is within the tolerance range, the photomask has guaranteed accuracy. Alternatively, even if the positional misalignment of position measurement marks 3A is outside the tolerance 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 at which the photomask is set in the exposure tool based on these values, it is possible to produce high-precision panels.

[0033] Furthermore, unit pattern formation region 1Aa is rectangular with a fixed aspect ratio, and position measurement marks 3A are placed at the four corners of similar shapes of unit pattern formation region 1Aa, i.e., at each intersection of the center line of marginal portion 1Ab. More specifically, position measurement marks 3A are placed at each intersection of the center line of marginal portion 1Ab so that the intersection of two orthogonal lines of position measurement mark 3A coincides with the intersection of the center line of marginal portion 1Ab. As a result, the position measurement results of each position measurement mark 3A can be expressed as a lattice model, as shown in FIG. 2, which makes it easy to determine whether or not there is a positional deviation (error) and the amount of that deviation. This makes it easy to visually confirm the positional accuracy of the unit pattern.

[0034] Furthermore, position measurement marks 3A are configured by a combination of lines extending in the first direction x and lines extending in the second direction y, and are formed only in portions of pattern formation region 1A where marginal portions 1Ab intersect. The first direction x and the second direction y coincide with the longitudinal direction of marginal portion 1Ab. Furthermore, position measurement marks of the same shape are not formed in the middle portions of marginal portions 1Ab, i.e., in the portions between adjacent unit pattern formation regions 1Aa, 1Aa. As a result, even if adjacent unit pattern formation regions 1Aa, 1Aa become closer and the width of marginal portion 1Ab becomes narrower, position measurement marks 3A do not invade unit pattern formation regions 1Aa, and unnecessary patterns are not formed in unit pattern formation regions 1Aa. This makes it possible to provide a photomask 1 on which position measurement marks 3A are formed in an appropriate shape.

[0035] Position measurement marks 3B are also formed in appropriate locations in outer edge region 1B. That is, position measurement marks 3B are also formed in locations near the marks (alignment marks 4) that serve as reference for the exposure tool. By measuring the positions of these marks 3B, the positional accuracy of the entire pattern can be confirmed.

[0036] <Position measurement mark (1)> Here, the position measurement marks 3 (3A, 3B) according to the first embodiment will be described with reference to FIGS.

[0037] As shown in FIG. 3, the position measurement mark 3 is composed of a combination of a line 3a extending along a first direction x and a line 3a extending along a second direction y. The two lines 3a have the same line width (Wx = Wy) and the same length (Lx = Ly) and intersect at their midpoints. This gives the position measurement mark 3 a plus (+) shape. The two lines 3a have their centers cut out by the same width (Gx = Gy). This gives the position measurement mark 3 a hollow structure in which the intersection of the two lines 3a is cut out. The hollow structure is used because if the two lines 3a overlap at the intersection during measurement with a coordinate measurement device, it would be noticeable, which is undesirable for measurement.

[0038] 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 lines 3a are not resolved on the panel during an exposure process (1:1 projection exposure, since this is for 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 a length that is easy for the coordinate measuring device to read. The gap widths Gx, Gy are 10 μm or more and 20 μm or less. These also apply to embodiments 2 to 4 described below.

[0039] The position measurement marks 3 are formed on a transparent substrate 2. The transparent substrate 2 is a substrate made of synthetic quartz glass or the like. The transparent substrate 2 has a transmittance of 95% or more for a representative wavelength (for example, 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 may be a mixed light containing at least two of these light types. Alternatively, the exposure light may have a wavelength band shifted or expanded to the shorter and / or longer wavelength side compared to these types of light. As an example, the wavelength band of the exposure light may be expanded from a broadband of 365 nm to 436 nm to 300 nm to 450 nm. However, the exposure light is not limited to these.

[0040] The position measurement mark 3 is made of a light-shielding film 5. The light-shielding film 5 is made of a Cr-based material, 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 for a representative wavelength included in the exposure light. Alternatively, the optical density (OD value) in the light-shielding portion may be 2.7 or more. As an example, the light-shielding film 5 has a layered structure including a first film layer and a second film layer. The first film layer is made of a Cr film and is intended to provide light-shielding properties. The second film layer is made of a chromium oxide film and is intended to suppress reflection. In this case, even if the transmittance of the first film layer is higher than 1%, it is sufficient as long as the layered transmittance of the first and second film layers is 1% or less.

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

[0042] The forming method is performed in a simultaneous process in the manufacturing direction of the photomask 1, i) Photomask blank preparation process (process 1) ii) Resist film formation process (process 2) iii) Drawing process (process 3) iv) Development process (Step 4) v) Light-shielding film etching process (process 5) vi) Resist film removal process (process 6) Equipped with.

[0043] The steps from the resist film forming step (step 2) to the resist film removing step (step 6) are called the patterning step. In the patterning step, the position measurement marks 3 are patterned (simultaneously with the patterning of the unit patterns).

[0044] In the photomask blank preparation step (step 1), as shown in FIGS. 4(a-1) and 4(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 a sputtering method, a vapor deposition method, or the like.

[0045] In the resist film forming step (step 2), as shown in FIGS. 4(b-1) and 4(b-2), a resist is uniformly applied onto the light-shielding film 5 to form a resist film 8. The resist is applied by a coating method or a spray method.

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

[0047] In the developing step (step 4), unnecessary resist film 8 is removed by development to form a resist pattern. Development is performed by immersing in a developer. The drawing step (step 3) and the developing step (step 4) are collectively referred to as the resist pattern forming step.

[0048] 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 an etching mask. Either dry etching or wet etching may be used for the etching, but wet etching is preferred for large-sized photomasks. An etching solution or etching gas is used as the etchant.

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

[0050] Through the above steps 1 to 6, the position measurement mark 3 is completed (together with the completion of the photomask 1).

[0051] <Position measurement mark (2)> Next, the position measurement marks 3 (3A, 3B) according to the second embodiment will be described with reference to FIGS.

[0052] As shown in FIG. 5, the position measurement mark 3 is composed of a combination of lines 3a extending along a first direction x and lines 3a extending along a second direction y. The two lines 3a have the same line width and length and intersect at their midpoints. This gives the position measurement mark 3 a plus (+) shape. The two lines 3a have their central portions cut out with the same width. This gives the position measurement mark 3 a hollow structure in which the intersection of the two lines 3a is cut out. Furthermore, the two lines 3a are divided into an inner portion 3b and an outer portion 3c with a gap between them. The inner portion 3b constitutes a first pattern of the position measurement mark 3. The outer portion 3c constitutes a second pattern of the position measurement mark 3. This means that the position measurement mark 3 is composed of a physically separated first pattern and second pattern.

[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-transmitting film 6. The light-shielding film 5 and the semi-transmitting film 6 are made of the same material, specifically a Cr-based material. In this embodiment, the light-shielding film 5 and the semi-transmitting film 6 are made of a Cr-based compound. Alternatively, the semi-transmitting film 6 may be made of a non-Cr-based material. The semi-transmitting film 6 is a phase shift film. Alternatively, the semi-transmitting film 6 may be a half-tone film. The semi-transmitting film 6 has a transmittance for a representative wavelength included in the exposure light that is lower than that of the transparent substrate 2 and higher than that of the light-shielding film 5, and is set to have a transmittance of 5% to 70% for the representative wavelength. The semi-transmitting film 6 may be a semi-transmitting metal film whose transmittance distribution within the plane of the photomask 1 is improved by adjusting the nitrogen content. The semi-transmitting film 6 may also contain other elements to change the optical density (OD value) of the semi-transmitting portion.

[0054] In the inner portion 3b of the position measurement mark 3, a semi-transparent film 6 is formed on the light-shielding film 5. The lines of the semi-transparent film 6 are formed slightly longer and slightly wider than the lines of the light-shielding film 5. As a result, both end faces and both side faces of the lines of the light-shielding film 5 are covered and protected by the semi-transparent film 6. In the inner portion 3b, a rim is formed on the peripheral edge because the lines of the semi-transparent 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 made of the same semi-transparent film 6 as the semi-transparent film 6 that is 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] 5 to 7, the light-shielding film 5 and the semi-transmitting film 6 are shown to have the same thickness. However, this is for convenience, and the actual thicknesses of the light-shielding film 5 and the semi-transmitting film 6 can be set as appropriate.

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

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

[0059] The steps from the resist film forming step (step 2) to the resist film removing step (step 6) are referred to as the 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 the 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).

[0060] In the photomask blank preparation step (step 1), as shown in FIGS. 6(a-1) and 6(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 a sputtering method, a vapor deposition method, or the like.

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

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

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

[0064] 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 an etching mask. Either dry etching or wet etching may be used for the etching, but wet etching is preferred for large-sized photomasks. An etching solution or etching gas is used as the etchant.

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

[0066] 7(a-1) and (a-2), in the semi-transparent film forming step (step 7), a semi-transparent 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 semi-transparent film 6 is formed by a sputtering method, a vapor deposition method, or the like.

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

[0068] In the second writing step (step 9), exposure light is irradiated onto the resist film 8 using an electron beam or laser of a writing device, and a resist pattern corresponding to the inner portion 3b and outer portion 3c of the position measurement mark 3 is written. 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 writing step (step 3).

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

[0070] In the semi-transparent film etching step (step 11), the exposed portion of the semi-transparent film 6 is removed by etching using the resist pattern as an etching mask. The etching may be either dry etching or wet etching, but wet etching is preferred for large-sized photomasks. An etching solution or etching gas is used as the etchant. At this time, the light-shielding film 5 is protected by the semi-transparent 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 7(c-2). The resist film 8 is removed by ashing or by immersion in a resist stripper.

[0072] Through the above steps 1 to 12, the position measurement mark 3 is completed (together with the completion of the photomask 1).

[0073] In this way, the position measurement mark 3 is formed in a first patterning process and a second patterning process. More specifically, the inner portion 3b (first pattern) of the position measurement mark 3 is formed in the first patterning process and the second patterning process, and the outer portion 3c (second pattern) of the position measurement mark 3 is formed in the second patterning process. Therefore, if an alignment error occurs between the first patterning process and the second patterning process, the inner portion 3b and the outer portion 3c will be formed misaligned. For this reason, by inspecting the position measurement mark 3, the alignment accuracy of the photomask 1 can be confirmed.

[0074] <Position measurement mark (3)> Next, the position measurement marks 3 (3A, 3B) according to the third embodiment will be described with reference to FIGS.

[0075] As shown in FIG. 8, the position measurement mark 3 is composed of a combination of lines 3a extending along a first direction x and lines 3a extending along a second direction y. The two lines 3a have the same line width and length and intersect at their midpoints. This gives the position measurement mark 3 a plus (+) shape. The two lines 3a have their central portions cut out with the same width. This gives the position measurement mark 3 a hollow structure in which the intersection of the two lines 3a is cut out. Furthermore, the two lines 3a are divided into an inner portion 3b and an outer portion 3c with a gap between them. The inner portion 3b constitutes a first pattern of the position measurement mark 3. The outer portion 3c constitutes a second pattern of the position measurement mark 3. This means that the position measurement mark 3 is composed of a physically separated first pattern and second pattern.

[0076] The inner portion 3b of the position measurement mark 3 is made up of a laminated film of a semi-transparent film 6, an intermediate film (etching stopper film) 7, and a light-shielding film 5. The light-shielding film 5 and the semi-transparent film 6 are made of the same material, specifically a Cr-based material. In this embodiment, a Cr-based compound is used for the light-shielding film 5 and the semi-transparent film 6. A non-Cr-based material is used for the intermediate film 7. In this embodiment, a Ni, Ti, or molybdenum silicide compound is used for the intermediate film 7. Alternatively, a non-Cr-based material may be used for the light-shielding film 5 and the semi-transparent film 6, and a Cr-based material may be used for the intermediate film 7.

[0077] The light-shielding film 5 and the semi-transparent film 6 have the same etching characteristics because they are made of the same material. However, the light-shielding film 5 and the semi-transparent film 6 have different etching characteristics from the intermediate film 7 because they are made of different materials. In other words, the light-shielding film 5 and the semi-transparent 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 semi-transparent film 6.

[0078] In the inner portion 3b of the position measurement mark 3, the intermediate film 7 is formed on the semi-transparent film 6, and the light-shielding film 5 is formed on the intermediate film 7. The lines of the semi-transparent film 6 are formed slightly longer and slightly wider than the lines of the light-shielding film 5 and the intermediate film 7. This causes the semi-transparent film 6 to protrude from both end faces and both side faces of the lines of the light-shielding film 5 and the intermediate film 7. In the inner portion 3b, the lines of the semi-transparent film 6 are slightly larger than the lines of the light-shielding film 5 and the intermediate film 7, so that a rim is formed on the peripheral edge.

[0079] The outer portion 3c of the position measurement mark 3 is made of the same semi-transparent film 6 as the semi-transparent film 6 that is 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 intermediate film 7 of the inner portion 3b.

[0080] 8 to 10, the semi-transmitting film 6, the intermediate film 7, and the light-shielding film 5 are shown to have the same thickness. However, this is for convenience, and the actual thicknesses of the semi-transmitting film 6, the intermediate film 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 the third embodiment will be described.

[0082] The forming method is performed in a simultaneous process in the manufacturing direction of the photomask 1, i) Photomask blank preparation process (process 1) ii) Resist film formation process (process 2) iii) Drawing process (process 3) iv) Development process (Step 4) v) Light-shielding film etching process (process 5) vi) Resist film removal process (process 6) vii) Intermediate film etching process (process 7) viii) Resist film formation process (process 8) ix) Drawing process (process 9) x) Development process (Step 10) xi) Semi-transparent film etching process (step 11) xii) Resist film removal step (step 12) Equipped with.

[0083] The steps from the resist film forming step (step 2) to the resist film removing step (step 6) are referred to as the 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 the 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).

[0084] 9(a-1) and 9(a-2), in the photomask blank preparation step (step 1), a photomask blank is prepared in which a semi-transparent film 6 is formed on a transparent substrate 2, an intermediate film 7 is formed on the semi-transparent film 6, and a light-shielding film 5 is formed on the intermediate film 7. The semi-transparent film 6, the intermediate film 7, and the light-shielding film 5 are each formed by a sputtering method, a vapor deposition method, or the like.

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

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

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

[0088] In the light-shielding film etching step (step 5), the exposed portions of the light-shielding film 5 are removed by etching using the resist pattern as an etching mask. Either dry etching or wet etching may be used, but wet etching is preferred for large-sized photomasks. An etching solution or etching gas is used as the etchant. Either etchant must have etching selectivity for the light-shielding film 5 (an etchant that does not etch the intermediate film 7).

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

[0090] In the intermediate film etching step (step 7), as shown in FIGS. 10(a-1) and (a-2), the exposed portion of the intermediate film 7 is etched away using the light-shielding film 5 as an etching mask. Either dry etching or wet etching may be used for the etching, but wet etching is preferred for large-sized photomasks. An etching solution or etching gas is used as the etchant. Whichever etchant is used, one that has etching selectivity for the intermediate film 7 (i.e., one that does not etch the light-shielding film 5 or the semi-transparent film 6) is used.

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

[0092] In the second writing step (step 9), exposure light is irradiated onto the resist film 8 using an electron beam or laser of a writing device, and a resist pattern corresponding to the inner portion 3b and outer portion 3c of the position measurement mark 3 is written. 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 writing step (step 3).

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

[0094] In the semi-transparent film etching step (step 11), the exposed portions of the semi-transparent film 6 are removed by etching using the resist pattern as an etching mask. Either dry etching or wet etching may be used, but wet etching is preferred for large-sized photomasks. An etching solution or etching gas is used as the etchant. Whichever etchant is used, an etchant that has etching selectivity for the semi-transparent film 6 (an etchant that does not etch the intermediate film 7) is used. However, the intermediate film 7 is protected by the resist and is not etched in the first place. Furthermore, 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 10(c-2). The resist film 8 is removed by ashing or by immersion in a resist stripper.

[0096] Through the above steps 1 to 12, the position measurement mark 3 is completed (together with the completion of the photomask 1).

[0097] In this way, the position measurement mark 3 is formed in a first patterning process and a second patterning process. More specifically, the inner portion 3b (first pattern) of the position measurement mark 3 is formed in the first patterning process and the second patterning process, and the outer portion 3c (second pattern) of the position measurement mark 3 is formed in the second patterning process. Therefore, if an alignment error occurs between the first patterning process and the second patterning process, the inner portion 3b and the outer portion 3c will be formed misaligned. For this reason, by inspecting the position measurement mark 3, the alignment accuracy of the photomask 1 can be confirmed.

[0098] <Position measurement mark (4)> Next, the position measurement marks 3 (3A, 3B) according to the fourth embodiment will be described with reference to FIGS.

[0099] As shown in FIG. 11 , the position measurement mark 3 is composed of a combination of lines 3a extending along a first direction x and lines 3a extending along a second direction y. The two lines 3a have the same line width and length and intersect at their midpoints. This gives the position measurement mark 3 a plus (+) shape. The two lines 3a have their central portions cut out with the same width. This gives the position measurement mark 3 a hollow structure in which the intersection of the two lines 3a is cut out. Furthermore, the two lines 3a are divided into an inner portion 3b and an outer portion 3c with a gap between them. The inner portion 3b constitutes a first pattern of the position measurement mark 3. The outer portion 3c constitutes a second pattern of the position measurement mark 3. This makes the position measurement mark 3 composed of a physically separated first pattern and second pattern.

[0100] The inner portion 3b of the position measurement mark 3 is made up of a laminated film of a semi-transparent film 6 and a light-shielding film 5. A Cr-based material is used for the light-shielding film 5. In this embodiment, a Cr-based compound is used for the light-shielding film 5. A non-Cr-based material is used for the semi-transparent film 6. In this embodiment, Ni, Ti, or a molybdenum silicide compound is used for the semi-transparent film 6. Alternatively, a non-Cr-based material may be used for the light-shielding film 5, and a Cr-based material may be used for the semi-transparent film 6.

[0101] The light-shielding film 5 and the semi-transmitting film 6 are made of different materials and therefore have different etching characteristics. That is, the light-shielding film 5 has etching selectivity relative to the semi-transmitting film 6, and the semi-transmitting film 6 has etching selectivity relative to the light-shielding film 5.

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

[0103] The outer portion 3c of the position measurement mark 3 is made of the same semi-transparent film 6 as the semi-transparent film 6 that is 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] 11 to 13, the semi-transmitting film 6 and the light-shielding film 5 are shown to have the same thickness. However, this is for convenience, and the actual thicknesses of the semi-transmitting 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 the fourth embodiment will be described.

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

[0107] The steps from the resist film forming step (step 2) to the resist film removing step (step 6) are referred to as the 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 the second patterning step. In the first patterning step, a 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, a 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 step (step 1), as shown in Figures 12(a-1) and 12(a-2), a photomask blank is prepared in which a semi-transparent film 6 is formed on a transparent substrate 2 and a light-shielding film 5 is formed on the semi-transparent film 6. The semi-transparent film 6 and the light-shielding film 5 are formed by a sputtering method, a vapor deposition method, or the like, respectively.

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

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

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

[0112] In the light-shielding film etching step (step 5), the exposed portions of the light-shielding film 5 are removed by etching using the resist pattern as an etching mask. Either dry etching or wet etching may be used, but wet etching is preferred for large-sized photomasks. An etching solution or etching gas is used as the etchant. Either etchant must have etching selectivity for the light-shielding film 5 (an etchant that does not etch the semi-transparent film 6).

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

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

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

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

[0117] In the semi-transparent film etching step (step 10), the exposed portion of the semi-transparent film 6 is removed by etching using the resist pattern as an etching mask. Either dry etching or wet etching may be used, but wet etching is preferred for large-sized photomasks. An etching solution or etching gas is used as the etchant. Whichever etchant is used, an etchant that has etching selectivity for the semi-transparent 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 13(b-2). The resist film 8 is removed by ashing or by immersion in a resist stripper.

[0119] Through the above steps 1 to 11, the position measurement mark 3 is completed (together with the completion of the photomask 1).

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

[0121] <Application example (method of manufacturing photomasks for FPDs consisting of multiple layers)> In conventional manufacturing methods for FPD photomasks, which are composed of multiple layers, each consisting of multiple photomasks as one layer, reference coordinates are set in a lithography system, and a patterning process is performed based on CAD data described using the reference coordinates. Therefore, position measurement of each photomask indicates an error relative to the reference coordinates. Furthermore, lithography systems and coordinate measurement systems have a certain measurement error. Therefore, overlay errors increase when the reference layer and the overlay layer are misaligned relative to the reference coordinates.

[0122] Therefore, a manufacturing method is used in which the amount of deviation and the angle of deviation are calculated from the position measurement results (see FIG. 15(a)) of the position measurement marks provided on a previously manufactured photomask (a reference mask serving as a reference layer), 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. Referring to FIG. 15(b), first, for the reference mask, the patterning process is performed, as usual, based on drawing data described using reference coordinates. After the reference mask is manufactured, the positions of the position measurement marks provided on the reference mask are measured, and the amount of deviation Δx in the first direction x, the amount of deviation Δy in the second direction y, and the deviation angle θ are calculated from the position measurement results. Then, the coordinate values ​​of the drawing data for the second and subsequent photomasks are converted and corrected using the values ​​of Δx, Δy, and θ. Then, for the second and subsequent photomasks, the patterning process is performed based on the corrected drawing data.

[0123] As described above, according to the method for manufacturing an FPD photomask of the application example, the result of drawing on the reference layer becomes the reference coordinates of the overlay layer, and the overlay error between the reference layer and the overlay layer can be minimized. Therefore, according to the method for manufacturing an FPD photomask of the application example, the overlay accuracy of the reference layer and the overlay layer can be improved. In other words, the method for manufacturing an FPD photomask of the application example is a technology that pursues overlay accuracy of each layer while allowing for positional misalignment, and is a technology that is superior in terms of delivery time and cost to correcting drawing data and remanufacturing a reference mask.

[0124] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0125] In the above-described first to fourth embodiments, the position measurement mark 3 has a hollow structure in which the intersection of the two lines 3a, 3a is cut out. However, the present invention is not limited to this. The position measurement mark may have a form in which the intersection of the two lines is not cut out but overlaps.

[0126] In the above-described first to fourth embodiments, the position measurement mark 3 has a + (plus) shape formed by two perpendicular lines 3a, 3a intersecting at their midpoints. However, the present invention is not limited to this. For example, the position measurement mark may have an L shape formed by two perpendicular lines intersecting at their endpoints, or a T shape formed by two perpendicular lines intersecting at their midpoints and their endpoints. Of course, in these cases, whether or not the intersection of the two lines is cut off can be appropriately set.

[0127] In the above-described first to fourth embodiments, the two lines 3a, 3a of the position measurement mark 3 are parallel to the first direction x and the second direction y. However, the present invention is not limited to this. The lines constituting the position measurement mark may have a slight angle with respect to the first direction x and the second direction y. The terms "along the first direction" and "along the second direction" are intended to include such forms.

[0128] Furthermore, in the above-described first to fourth embodiments, the position measurement mark 3A is formed only in the portion of the pattern formation region 1A where the marginal portions 1Ab intersect. However, the present invention is not limited to this. As shown in Fig. 14, if the length Lx of one line 3a is short and the position measurement mark 3C is of a form that does not intrude into the unit pattern formation region 1Aa, it may be formed in the middle portion of the marginal portion 1Ab, that is, in the portion between adjacent unit pattern formation regions 1Aa, 1Aa.

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

[0130] Furthermore, in the above-described first to fourth embodiments, it is assumed that position measurement mark 3A is formed in a portion of pattern formation region 1A where marginal portions 1Ab intersect. However, in the method for forming a position measurement mark in an FPD photomask according to the present invention, which is embodied in the above-described second to fourth embodiments, the location where the position measurement mark is formed is not particularly limited. The method for forming a position measurement mark in an FPD photomask according to the present invention can be established as a new and innovative elemental technical invention, regardless of the location where the position measurement mark is formed.

[0131] In the above-described first to fourth embodiments, the inner portion 3b of the position measurement mark 3A forms the first pattern, and the outer portion 3c forms the second pattern. However, the present invention is not limited to this. The outer portion of the position measurement mark may form the first pattern, and the inner portion may form the second pattern.

[0132] In the above-described first to fourth embodiments, 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 to this. 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 of the present invention can be exposed using an exposure tool known for use in FPDs. For example, the exposure tool can be a 1:1 projection exposure tool that uses exposure light from a single wavelength or broadband light source with a peak at 300 to 500 nm, has a numerical aperture (NA) of around 0.09 (0.07 to 0.12), and has a 1:1 optical system with a coherence factor (σ) that is within the conventional range. It should be noted that a numerical aperture of 0.12 or greater is also applicable. Of course, the photomask of 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, 1B...outer edge area, 2...transparent substrate, 3, 3A to 3C...position measurement mark, 3a...line, 3b...inner part, 3c...outer part, 4...alignment mark, 5...light-shielding film, 6...semi-transparent film, 7...intermediate film (etching stopper film), 8...resist film, Wx, Wy...line width, Lx, Ly...line length, Gx, Gy...gap width, Δx...shift amount in first direction x, Δy...shift amount in second direction y, θ...shift 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 orthogonal 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 extending along a first direction and lines extending along a second direction, and are formed only in portions where margins intersect in the pattern formation region; The position measurement mark has a shape in which a line extending in a first direction and a line extending in a second direction intersect, and is formed separately into an inner portion and an outer portion. Photomasks for FPDs.

2. 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 either the first functional film or the second functional film. The photomask for FPD according to claim 1 .

3. 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 orthogonal 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 extending along a first direction and lines extending along a second direction, and are formed only in portions where margins intersect in the pattern formation region; The outer edge region is provided with a positioning mark that is made up of lines with a line width wider than the line width of the line that makes up the position measurement mark. Photomasks for FPDs.

4. The position measurement mark has a form in which a line extending in a first direction and a line extending in 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 marginal portion.

4. The photomask for FPD according to claim 1.

5. The position measurement mark has a shape in which a line extending in a first direction and a line extending in 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 area.

6. The photomask for FPD according to claim 1.

7. A method for forming a position measurement mark on a photomask for an FPD according to claim 1, comprising: one of the inner portion and the outer portion of the position measurement mark is defined as a first pattern, and the other of the inner portion and the outer portion is defined as a second pattern, thereby 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 step. A method for forming a position measurement mark on a photomask for an FPD.

8. 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 formed and then a second patterning step is performed.

8. A method for forming a position measurement mark on a photomask for an FPD according to claim 7.

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

8. A method for forming a position measurement mark on a photomask for an FPD according to claim 7.

10. 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, the second patterning step is performed.

8. A method for forming a position measurement mark on a photomask for an FPD according to claim 7.

11. A method for manufacturing a second or subsequent photomask of a photomask for an FPD, which is configured with a plurality of layers, each of which is one layer and includes a plurality of photomasks as one set, the method comprising: The deviation amounts and deviation angles in the first and second directions perpendicular to each other are obtained from the position measurement results of the position measurement marks provided on the first photomask that has been manufactured previously, 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 an FPD.

Images