Pattern correction method and photomask

Abstract

Make large-scale pattern modifications at once. [Solution] A pattern repair method according to one embodiment of the present invention is a pattern repair method for repairing a new pattern on a photomask (10) on which a pattern has already been formed by a first light-shielding film (11) containing a first material on a transparent substrate (2), and includes a film formation process for forming an etching stopper film (21) and a second light-shielding film (22) containing the first material in this order, a photoresist film formation process for forming a photoresist film (23), a pattern formation process for forming a photoresist pattern, a light-shielding film removal process for removing a portion of the second light-shielding film (22) using the photoresist pattern as a mask, and an etching stopper film removal process for removing the etching stopper film (21).

Description

[Technical Field]

[0001] The present invention relates to a pattern repair method for repairing a pattern on a photomask on which a pattern has already been formed. [Background technology]

[0002] For example, a technique is known for correcting a pattern on a photomask that has already been used, i.e., a photomask on which a pattern has already been formed. By correcting the pattern on a photomask on which a pattern has already been formed, a photomask can be produced more cheaply than by producing a new photomask. For example, Patent Document 1 discloses a technique for correcting a photomask pattern using CVD (Chemical Vapor Deposition). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-140744 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technique described in Patent Document 1 has a problem in that the area that can be repaired at one time is small, and therefore it takes a long time to repair a large-scale pattern.

[0005] An object of one aspect of the present invention is to realize a pattern repair method that can repair a large-scale pattern at once. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a pattern repair method according to one embodiment of the present invention is a pattern repair method for repairing a new pattern on a photomask on which a pattern has already been formed by a first pattern formation portion containing a first material on a transparent substrate, the method including: a film formation step of forming an etching stopper film and a second pattern formation portion containing a second material of the same metal system as the first material, in this order, on the surface of the photomask on which the pattern has been formed; a photoresist film formation step of forming a photoresist film on the surface of the photomask so as to cover the entire surface of the second pattern formation portion; a pattern formation step of drawing on the photoresist film with a drawing device to form a photoresist pattern; a first removal step of removing a part of the second pattern formation portion using the photoresist pattern as a mask; and an etching stopper film removal step of removing the second pattern formation portion not removed in the first removal step or the etching stopper film using the photoresist pattern as a mask. [Effects of the Invention]

[0007] According to one aspect of the present invention, large-scale pattern correction can be performed at once. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a plan view showing an example of a photomask whose pattern is to be repaired by the pattern repair method according to the first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of an area D1 shown in FIG. [Figure 3] 1 is a diagram showing a portion of a pattern to be corrected by the pattern correction method according to the first embodiment of the present invention. FIG. [Figure 4] 3 is a flowchart showing an example of a pattern correction method according to the first embodiment of the present invention. [Figure 5] 1A to 1C are diagrams illustrating a pattern repair method according to the first embodiment of the present invention. [Figure 6] FIG. 2 is a diagram showing a pattern formation region A after being repaired by the pattern repair method according to the first embodiment of the present invention. [Figure 7] FIG. 10 is an enlarged view of one pattern formation region on a photomask that is the target of pattern correction in this modification of the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view taken along the line AA in FIG. 7. [Figure 9] FIG. 10 is a diagram showing a pattern formation region after the pattern has been corrected by the pattern correction method of the modified example. [Figure 10] FIG. 10 is a cross-sectional view taken along the line BB shown in FIG. 9. [Figure 11] FIG. 10 is a diagram showing another example of a pattern formation region after the pattern has been corrected by the pattern correction method of the modified example. [Figure 12] FIG. 10 is a diagram showing yet another example of a pattern formation region after the pattern has been corrected by the pattern correction method of the modified example. [Figure 13] FIG. 10 is an enlarged view of one pattern formation region on a photomask that is the target of pattern correction in another modification of the first embodiment. [Figure 14] FIG. 14 is a cross-sectional view taken along the line CC shown in FIG. [Figure 15] FIG. 10 is a diagram showing a pattern formation region after the pattern has been corrected by the pattern correction method of the modified example. [Figure 16] FIG. 16 is a cross-sectional view taken along the line EE shown in FIG. [Figure 17] 10A and 10B are diagrams for explaining another pattern correction method of the above modified example. [Figure 18] 10A and 10B are diagrams for explaining another pattern correction method of the above modified example. [Figure 19] FIG. 10 is an enlarged view of one pattern formation region on a photomask that is the target of pattern correction in another modification of the first embodiment. [Figure 20] FIG. 20 is a cross-sectional view taken along the line FF shown in FIG. 19. [Figure 21] FIG. 10 is a diagram showing a pattern formation region after the pattern has been corrected by the pattern correction method of the modified example. [Figure 22] FIG. 22 is a cross-sectional view taken along the line GG shown in FIG. 21. [Figure 23] FIG. 10 is an enlarged view of one pattern formation region on a photomask that is the target of pattern correction in another modification of the first embodiment. [Figure 24] 10A to 10C are diagrams for explaining a pattern correction method in the modified example. [Figure 25] 10A to 10C are diagrams for explaining a pattern correction method in the modified example. [Figure 26] FIG. 10 is a plan view of the photomask after repairing by the pattern repairing method according to the modified example. [Figure 27] 10A to 10C are diagrams for explaining a pattern correction method according to another modified example of the first embodiment. [Figure 28] 10A to 10C are diagrams for explaining a pattern correction method in the modified example. [Figure 29] 10A to 10C are diagrams for explaining a pattern correction method according to another modified example of the first embodiment. [Figure 30] 10A to 10C are diagrams for explaining a pattern correction method in the modified example. [Figure 31] 10A to 10C are diagrams for explaining a pattern correction method according to another modified example of the first embodiment. [Figure 32] 10A to 10C are diagrams for explaining a pattern correction method in the modified example. [Figure 33] FIG. 10 is a plan view showing an example of a photomask on which a pattern is to be repaired by the pattern repair method according to the second embodiment of the present invention. [Figure 34] FIG. 34 is an enlarged view of an area D4 shown in FIG. [Figure 35] FIG. 10 is a diagram showing a portion of a pattern to be corrected by a pattern correction method according to a second embodiment of the present invention. [Figure 36] 10 is a flowchart showing an example of a pattern correction method according to a second embodiment of the present invention. [Figure 37] 10A and 10B are diagrams for explaining a pattern repair method according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will be described in detail below. In this embodiment, a pattern repair method for repairing a new pattern on a photomask on which a pattern has already been formed by a light-shielding film on a transparent substrate will be described. In this specification, a "photomask on which a pattern has already been formed" refers to a photomask on which a pattern has been formed on a transparent substrate, which is a photomask that has been manufactured as a finished product through a series of manufacturing processes, and may be, for example, a photomask that has already been used.

[0010] Fig. 1 is a plan view showing the configuration of a photomask 10 as an example of a photomask whose pattern is to be repaired by the pattern repair method of this embodiment. Fig. 2 is an enlarged view of region D1 shown in Fig. 1, showing one pattern formation region A in an enlarged view.

[0011] As shown in FIG. 1, the photomask 10 has a plurality of pattern formation regions A formed on a transparent substrate 2. The transparent substrate 2 is made of a substrate such as synthetic quartz glass. The transparent substrate 2 has a transmittance of 95% or more for the representative wavelength contained in the exposure light in the exposure step. The representative wavelength of the exposure light may be, for example, i-line, h-line, or g-line, or a mixture thereof, but is not limited to these.

[0012] In the pattern formation region A, as shown in FIG. 2, a pattern (hereinafter also referred to as a first pattern) is formed on the transparent substrate 2 by a first light-shielding film 11 (first pattern formation portion) containing a material (hereinafter referred to as a first material) that does not transmit light (i.e., has light-shielding properties). The first light-shielding film 11 preferably has an optical density OD value of 2.7 or higher, and may be made of, for example, a chromium film. Note that, to prevent stray light from occurring during exposure, anti-reflection films may be laminated and formed on both sides of the first light-shielding film 11.

[0013] In the pattern formation region A, a region where the first light-shielding film 11 is not formed becomes a light-transmitting portion 12 that transmits light. In this embodiment, an example will be described in which a circular first light-shielding film 11 is formed in one pattern formation region A. As shown in FIG. 1 , the photomask 10 has alignment marks 4 formed at the four corners of the transparent substrate 2. The alignment marks 4 are provided as references for positioning the photomask 10 when the first light-shielding film 11 is patterned on the photomask 10.

[0014] 3 is a diagram showing a portion of a pattern to be corrected by the pattern correction method of this embodiment. In this embodiment, as shown in FIG. 3, an example of correcting a pattern so as to form a new light-shielding portion in an area D2 adjacent to the inside of a circle formed by the first light-shielding film 11, and in an area D3 located in the center of the circle and not adjacent to the first light-shielding film 11, will be described. Note that, although this embodiment will describe one pattern formation area A, patterns in other pattern formation areas A will also be corrected as necessary.

[0015] Fig. 4 is a flowchart showing an example of a pattern repair method according to this embodiment. Fig. 5 is a diagram for explaining the pattern repair method according to this embodiment. Each diagram shown in Fig. 5 is a cross-sectional view taken along a plane that passes through the center of a circle formed by the first light-shielding film 11 and is perpendicular to the surface of the transparent substrate 2. As shown in Figs. 4 and 5, in the pattern repair method according to this embodiment, first, a photomask 10 is prepared on the transparent substrate 2, on which a first pattern has already been formed by the first light-shielding film 11 (step S1).

[0016] Next, an etching stopper film 21 and a second light-shielding film 22 (second pattern formation portion) containing a second material of the same metal system as the first material are formed in this order on the surface of the photomask 10 on which the first pattern is formed (step S2, film formation process). In this specification, a member used when correcting a pattern in the pattern correction method of the present invention and used as a photomask pattern after correction is referred to as a "second pattern formation portion." The etching stopper film 21 and the second light-shielding film 22 are formed by, for example, a sputtering method or a vapor deposition method. The first material is a material consisting of a first metal element (e.g., Cr, Ni, etc.) and a first nonmetal element, and the second material is a material consisting of a second nonmetal element different from the first metal element and the first nonmetal element. The etching stopper film 21 is made of a material that is not etched by a solvent used to etch the second light-shielding film 22. For example, titanium, nickel, molybdenum silicide, etc. can be used as the etching stopper film 21.

[0017] Thereafter, a photoresist film 23 is formed on the entire surface of the photomask 10 including the second light-shielding film 22 (step S3, photoresist film forming step). In other words, the photoresist film 23 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22. The photoresist film 23 is formed by, for example, a coating method, a spray method, or the like.

[0018] Next, a photoresist pattern is formed on the photoresist film 23 by using a drawing device and then developing (step S4, pattern formation step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 22 corresponding to the regions D2 and D3 shown in FIG. 3 is not removed in the first removal step described below. Development is performed by a puddle method, a dipping method, a spray method, a spin method, or the like.

[0019] In step S4 of this embodiment, the photomask 10 is positioned using the alignment marks 4, which are formed on the transparent substrate 2 of the photomask 10 at the same time as the first pattern is formed by the first light-shielding film 11, as a reference, and then drawing is performed by a drawing device. In other words, the drawing device draws on the photoresist film 23 using the alignment marks 4 as a reference. This makes it possible to control the position at which the newly added pattern is to be added with high precision. Note that if precision in the position at which the additional pattern is formed is not required, there is no need to position the photomask 10 using the alignment marks 4.

[0020] Next, using the photoresist pattern formed in step S4 as a mask, a portion of the second light-shielding film 22 is removed (step S5, first removal step). As a result, of the second light-shielding film 22 formed in step S2, the second light-shielding film 22 other than the second light-shielding film 22 corresponding to the region D2 and the region D3 shown in Fig. 3 is removed. In step S4, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0021] Next, the remaining photoresist film 23 is removed (step S6). The photoresist film 23 can be removed by, for example, a puddle method, an ashing method, or immersion in a resist stripper. Finally, the etching stopper film 21 is removed using the second light-shielding film 22 that was not removed in step S5 as a mask (step S7, etching stopper film removal step). This makes it possible to fabricate a photomask in which a new light-shielding portion is added by the second light-shielding film 22 while leaving the first light-shielding film 11 that was originally formed on the photomask 10.

[0022] 6 is a diagram showing the pattern formation region A after being repaired by the pattern repair method of this embodiment. As shown in FIG. 6, in the pattern formation region A after the pattern repair, a second light-shielding film 22 is formed in the region D2 and the region D3 shown in FIG. 3. By forming the second light-shielding film 22 in the region D2, the area of the light-shielding region formed by the first light-shielding film 11 before the pattern repair can be increased. In other words, when the photomask 10 is viewed in plan, the width of the light-shielding region formed by the first light-shielding film 11 can be increased. Furthermore, by forming the second light-shielding film 22 in the region D3, an additional light-shielding region can be formed.

[0023] As described above, in the pattern repair method of this embodiment, the etching stopper film 21 and the second light-shielding film 22 made of the first material constituting the first light-shielding film 11 are formed on the entire surface of the existing photomask 10, and the second light-shielding film 22 is patterned by photolithography. This configuration allows the second light-shielding film 22 to be additionally patterned on the entire surface of the photomask 10. In other words, the pattern repair method of this embodiment allows large-scale pattern repair to be performed at once. As a result, pattern repair can be performed in a short time on a pattern of a photomask on which a pattern has already been formed.

[0024] Furthermore, in the pattern repair method of this embodiment, an additional light-shielding region is formed by a second light-shielding film 22 made of the same metal-based material as the first material constituting the first light-shielding film 11. This allows the same cleaning solution to be used for cleaning the repaired photomask 10 as for the unrepaired photomask 10. The materials constituting the first light-shielding film 11 and the second light-shielding film 22 (i.e., the first material and the second material) can be selected from known materials such as Cr-based metal compounds, Si-based compounds, and metal silicide compounds. For example, the material constituting the first light-shielding film 11 and the second light-shielding film 22 can be a Cr-based metal compound containing one or more of metal Cr, Cr oxide, Cr nitride, Cr carbide, Cr oxynitride, Cr carbide nitride, Cr oxycarbide, and Cr oxynitride carbide.

[0025] Furthermore, the pattern repair method of this embodiment does not involve the risk of film peeling, which occurs when using CVD, such as the technology of Patent Document 1. Furthermore, when using CVD, such as the technology of Patent Document 1, the laser is irradiated onto areas other than the desired area, resulting in the formation of light-shielding portions outside the desired area, which must be removed while being shaped. In contrast, the pattern repair method of this embodiment uses a drawing device to pattern the second light-shielding film 22, allowing for the addition of patterns with high precision and eliminating the need to remove unnecessary light-shielding portions.

[0026] In the pattern correction method of this embodiment, in step S4 (pattern formation process), the photomask 10 is positioned using the alignment marks 4 as a reference, and then the patterning is performed by the patterning device. However, there are cases where the alignment marks 4 are not formed on the photomask 10. In this case, the photomask 10 may be positioned as follows.

[0027] First, before step S3 (photoresist film formation process), an alignment mark is formed on the second light-shielding film 22. Then, the positional relationship and inclination deviation between the formed alignment mark and the target pattern originally formed on the uncorrected photomask 10 are determined, and the drawing position by the drawing device in step S4 is corrected based on the positional relationship and deviation. The target pattern is not particularly limited as long as it is a pattern whose position formed on the uncorrected photomask 10 is known, and for example, an alignment mark for transfer exposure, a mark for measuring a length, etc. can be used.

[0028] According to this configuration, even if an alignment mark 4 is not formed on the photomask 10, the position to be drawn by the drawing device can be corrected using a newly created alignment mark, so that an additional pattern can be formed with high precision.

[0029] The photomask repaired by the pattern repair method of this embodiment is a photomask in which a new pattern has been added to a photomask in which a first pattern has already been formed on a transparent substrate 2 by a first light-shielding film 11, and has: (1) the first pattern; (2) a pattern (second pattern) of a light-shielding region formed by an etching stopper film 21 and a second light-shielding film 22, which is a pattern formed adjacent to the first pattern when the photomask is viewed on the transparent substrate 2 in a planar view; and (3) a pattern (second pattern) formed by an etching stopper film 21 and a second light-shielding film 22, which is a pattern formed so as not to be adjacent to the first pattern when the photomask is viewed in a planar view.

[0030] <Variation 1> In the first embodiment, a pattern correction method for forming a new light-shielding portion using a second light-shielding film 22 on a photomask on which a first pattern has already been formed using a first light-shielding film 11 has been described, but the present invention is not limited to this. In one aspect of the present invention, the method can be applied to a photomask on which a first pattern is formed using a film other than a light-shielding film. Details will be described with reference to FIGS. 7 to 10.

[0031] FIG. 7 is an enlarged view of one pattern formation region A in a photomask 10 that is the target of pattern repair in this modified example. FIG. 8 is a cross-sectional view taken along the line AA in FIG. 7. The photomask 10 that is the target of repair in this modified example is a top-type photomask. FIG. 9 is a view showing the pattern formation region A after the pattern has been repaired by the pattern repair method of this modified example. FIG. 10 is a cross-sectional view taken along the line BB in FIG. 9.

[0032] 7 and 8, the photomask 10 to be subjected to pattern correction in this modified example has a pattern (first pattern) formed in a pattern formation region A by a first light-shielding film 11 and a semi-transparent film 13 that transmits a portion of irradiated light, which serve as a first pattern formation portion. More specifically, as shown in FIG. 8, the first light-shielding film 11 is formed in a portion of the pattern formation region A, and the semi-transparent film 13 is formed in a region of the first light-shielding film 11 opposite the transparent substrate 2 side and in a portion of the region of the pattern formation region A where the first light-shielding film 11 is not formed. In other words, the semi-transparent film 13 is formed in a portion of the pattern formation region A, and the first light-shielding film 11 is disposed in a portion between the semi-transparent film 13 and the transparent substrate 2. With this configuration, the photomask 10 to be subjected to pattern correction is a half-tone mask in which, when the photomask 10 is viewed from above, the region where the semi-transparent film 13 and the first light-shielding film 11 overlap is a light-shielding region, and the region where only the semi-transparent film 13 is formed is a semi-transparent region.

[0033] Next, a method for correcting the pattern of the photomask 10 having the above configuration will be described. First, an etching stopper film 21 and a second light-shielding film 22 (second pattern forming portion) containing a second material of the same metal system as the material (first material) constituting the semi-transparent film 13 are formed in this order on the surface of the photomask 10 on which the first pattern is formed (film forming step).

[0034] Thereafter, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 22 (photoresist film forming step). In other words, a photoresist film is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22.

[0035] Next, a photoresist pattern is formed by drawing on the photoresist film using a drawing device and then developing it (pattern formation step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 22 in the area corresponding to the area where a new light-shielding area is to be added is not removed in the first removal step described below.

[0036] Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 22 is removed (first removal step). In the first removal step, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0037] Next, the remaining photoresist film is removed. Finally, the etching stopper film 21 is removed using the second light-shielding film 22 that was not removed in the first removal step as a mask (etching stopper film removal step). As a result, as shown in Figures 9 and 10, a photomask can be produced in which a new light-shielding region is added by the second light-shielding film 22 while leaving the first pattern originally formed on the photomask 10 by the first light-shielding film 11 and the semi-transparent film 13.

[0038] 11 is a diagram showing another example of the pattern formation region A after the pattern has been corrected by the pattern correction method of this modified example. As shown in FIG. 11, in one aspect of the present invention, the second light-shielding film 22 may be formed so that a portion of the second light-shielding film 22 overlaps a portion of the first pattern (more specifically, a portion of the region of the first pattern where the first light-shielding film 11 is formed) when the photomask 10 is viewed in plan. This allows the shape of the light-shielding region in the photomask 10 to be changed.

[0039] 12 is a diagram showing yet another example of the pattern formation region A after the pattern has been repaired by the pattern repair method of this modified example. As shown in FIG. 12, in one embodiment of the present invention, the second light-shielding film 22 may be formed so as to include the entire region of the first pattern that was formed by the first light-shielding film 11 and the semi-transparent film 13 when the photomask 10 is viewed in plan. This makes it possible to increase the area of the light-shielding region in the photomask 10. However, in this case, the semi-transparent effect that the photomask 10 had before the repair will be lost.

[0040] In this modified example, a method for correcting a pattern on a photomask in which a pattern (first pattern) is formed by a first light-shielding film 11 and a semi-transparent film 13 as a first pattern forming portion has been described. However, in one aspect of the present invention, pattern correction may also be performed in a similar manner on a photomask that uses a phase shift film instead of the first light-shielding film 11.

[0041] <Variation 2> The pattern repair methods described above can also be applied to a photomask in which the first pattern is formed using a phase shift film. A phase shift film is a semi-transparent film with a transmittance of approximately 1 to 15% that has the effect of inverting (or shifting) the phase, and the phase shift effect improves resolution. However, as in the example shown in Figure 12, if the second light-shielding film 22 is formed so as to include the entire area of the first pattern formed using the phase shift film when the photomask 10 is viewed in plan, the phase shift effect of the photomask 10 before repair will be lost.

[0042] When photomask 10 in which the first pattern is formed of a phase shift film is corrected, the correction may be performed using a phase shift film instead of second light-shielding film 22. This allows the shape of the region having the phase shift effect to be changed. However, as in the example shown in FIG. 12, if the phase shift film is formed so as to include the entire region of the first pattern formed by the phase shift film when photomask 10 is viewed in plan, the phase shift effect disappears in the region where the phase shift film overlaps when photomask 10 is viewed in plan, resulting in a photomask in which the phase shift effect is obtained only in the region where only the newly formed phase shift film is present (i.e., an edge-enhancement photomask).

[0043] <Variation 3> In the first modification, a method for correcting a pattern of a top-type half-tone mask has been described, but the present invention is not limited to this. The pattern correction method of one aspect of the present invention can also be applied to a bottom-type half-tone mask. Details will be described with reference to Figures 13 to 16.

[0044] Fig. 13 is an enlarged view of one pattern formation region A in the photomask 10 that is the target of pattern repair in this modified example. Fig. 14 is a cross-sectional view taken along the arrow CC in Fig. 13. Fig. 15 is a view showing the pattern formation region A after the pattern has been repaired by the pattern repair method of this modified example. Fig. 16 is a cross-sectional view taken along the arrow EE in Fig. 15.

[0045] As shown in FIGS. 13 and 14 , the photomask 10 to be subjected to pattern correction in this modified example has a pattern (first pattern) formed in a pattern formation region A by a first light-shielding film 11 as a first pattern formation portion and a semi-transparent film 13 that transmits a portion of the irradiated light. More specifically, as shown in FIG. 14 , the semi-transparent film 13 is formed in a portion of the pattern formation region A, and an etching stopper film 14 and the first light-shielding film 11 are laminated in this order on a portion of the layer on the side opposite the transparent substrate 2 side of the semi-transparent film 13. Due to this configuration, the photomask 10 to be subjected to pattern correction in this modified example is a half-tone mask in which, when viewed from above, the region where the semi-transparent film 13 and the first light-shielding film 11 overlap is a light-shielding region, and the region where only the semi-transparent film 13 is a semi-transparent region. The semi-transparent film 13 and the first light-shielding film 11 are made of the same metal-based material.

[0046] Next, a description will be given of a method for correcting a pattern on the photomask 10 having the above-described configuration. First, an etching stopper film 21 and a second light-shielding film 22 (second pattern forming portion) containing a second material of the same metal system as the material (first material) constituting the first light-shielding film 11 and the semi-transparent film 13 are formed in this order on the surface of the photomask 10 on which the first pattern is formed (film forming step).

[0047] Thereafter, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 22 (photoresist film forming step). In other words, a photoresist film is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22.

[0048] Next, a photoresist pattern is formed by drawing on the photoresist film using a drawing device and then developing it (pattern formation step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 22 in the area corresponding to the area where a new light-shielding area is to be added is not removed in the first removal step described below.

[0049] Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 22 is removed (first removal step). In the first removal step, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0050] Next, the remaining photoresist film is removed. Finally, the etching stopper film 21 is removed using the second light-shielding film 22 that was not removed in the first removal step as a mask (etching stopper film removal step). As a result, as shown in Figures 15 and 16, a photomask can be produced in which a new light-shielding region is added by the second light-shielding film 22 while leaving the first pattern originally formed on the photomask 10 by the first light-shielding film 11 and the semi-transparent film 13.

[0051] In this modified example, a method for correcting a pattern on a photomask in which a pattern (first pattern) is formed by a first light-shielding film 11 and a semi-transparent film 13 as a first pattern forming portion has been described. However, in one aspect of the present invention, pattern correction may also be performed on a photomask that uses a phase shift film instead of the first light-shielding film 11. The phase shift film has the function of shifting the phase of exposure light, and has the property that the phase of the exposure light is inverted by a single film (i.e., the phase shift angle is approximately 180°). However, "approximately 180°" here means 180°±20°, and refers to a phase difference of the exposure light that provides a sufficient interference effect of the exposure light.

[0052] In one embodiment of the present invention, when pattern correction is performed on a photomask that uses a phase shift film instead of the first light-shielding film 11, a semi-transparent film that partially transmits exposure light may be used instead of the second light-shielding film 22. In this case, the transmittance of the phase shift film is preferably 3 to 15%. In another embodiment of the present invention, when pattern correction is performed on a photomask that uses a semi-transparent film instead of the first light-shielding film 11, a phase shift film may be used instead of the second light-shielding film 22. In this case, it is preferable that the semi-transparent film has a transmittance to the exposure light of 10 to 70% and a phase shift angle of 0.1° to 20°.

[0053] Next, a pattern correction method for adding a new light-shielding region to photomask 10, which is a bottom-type half-tone mask shown in Figures 13 and 14, and correcting a part of a region that was originally a light-shielding region due to first light-shielding film 11 to be a semi-transmitting region will be described with reference to Figures 17 and 18. Figures 17 and 18 are diagrams for explaining the pattern correction method. Each of the views shown in Figures 17 and 18 corresponds to the cross-sectional view taken along line DD in Figure 13.

[0054] 17, in this pattern repair method, a photomask 10 is prepared in which a pattern (first pattern) is formed on a transparent substrate 2 using a first light-shielding film 11, a semi-transparent film 13, and an etching stopper film 14 (step S11). Next, an etching stopper film 21 and a second light-shielding film 22 (second pattern formation portion) containing the first material are formed in this order on the surface of the photomask 10 on which the first pattern is formed (step S12, film formation step). Thereafter, a photoresist film 23 is formed on the entire surface of the photomask 10, including the second light-shielding film 22 (step S13, photoresist film formation step). In other words, the photoresist film 23 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22.

[0055] Next, a photoresist pattern is formed on the photoresist film 23 by drawing with a drawing device and then developing (step S14, pattern formation step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 22 corresponding to the area to be newly changed to a light-shielding area is not removed in the first removal step described later.

[0056] Next, using the photoresist pattern formed in step S14 as a mask, a part of the second light-shielding film 22 is removed (step S15, first removal step). In step S15, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0057] 18, using the photoresist pattern formed in step S14 as a mask, a portion of the etching stopper film 21 is removed (step S16). Next, using the photoresist pattern formed in step S14 as a mask, a portion of the first light-shielding film 11 is removed (step S17). Thereafter, using the photoresist pattern formed in step S14 as a mask, a portion of the etching stopper film 14 is removed (step S18). Finally, the remaining photoresist film 23 is removed (step S19).

[0058] By using the above method, a new light-shielding area is added by the second light-shielding film 22, and when the photomask is viewed in a plane, the semi-transparent film 13 is exposed in part of the area that was originally a light-shielding area by the first light-shielding film 11, thereby changing part of the light-shielding area into a semi-transparent area.

[0059] <Variation 4> In Modification 3, a method for correcting a pattern of a bottom-type halftone mask configured with a semi-transparent film 13 and a first light-shielding film 11, which are made of the same metal material, and an etching stopper film 14 disposed between the semi-transparent film 13 and the first light-shielding film 11, has been described, but the present invention is not limited to this. The pattern correction method of one embodiment of the present invention can also be applied to bottom-type halftone masks having other configurations. Details will be described with reference to Figures 19 to 22.

[0060] Fig. 19 is an enlarged view of one pattern formation region A in the photomask 10 that is the target of pattern repair in this modified example. Fig. 20 is a cross-sectional view taken along the line FF in Fig. 19. Fig. 21 is a view showing the pattern formation region A after the pattern has been repaired by the pattern repair method of this modified example. Fig. 22 is a cross-sectional view taken along the line GG in Fig. 21.

[0061] As shown in FIGS. 19 and 20 , the photomask 10 to be subjected to pattern correction in this modification has a pattern (first pattern) formed by a first light-shielding film 11 and a semi-transparent film 13 that transmits a portion of the irradiated light, which serve as a first pattern forming portion. More specifically, as shown in FIG. 20 , the semi-transparent film 13 is formed in a portion of the pattern forming region A, and the first light-shielding film 11 is laminated on the layer opposite the transparent substrate 2 side of the semi-transparent film 13. Due to this configuration, the photomask 10 to be subjected to pattern correction in this modification is a half-tone mask in which, when viewed from above, the overlapping region of the semi-transparent film 13 and the first light-shielding film 11 constitutes a light-shielding region, and the region consisting only of the semi-transparent film 13 constitutes a semi-transparent region. The first light-shielding film 11 and the semi-transparent film 13 are made of different metal-based materials. For example, the first light-shielding film 11 is made of a Cr-based material, and the semi-transparent film 13 is made of MoSi, which serves as a third material.

[0062] Next, a description will be given of a method for correcting a pattern on the photomask 10 having the above configuration. First, an etching stopper film 21 and a second light-shielding film 22 (second pattern formation portion) are formed in this order on the surface of the photomask 10 on which the first pattern is formed (film formation step).

[0063] Thereafter, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 22 (photoresist film forming step). In other words, a photoresist film is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22.

[0064] Next, a photoresist pattern is formed by drawing on the photoresist film using a drawing device and then developing it (pattern formation step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 22 in the area corresponding to the area where a new light-shielding area is to be added is not removed in the first removal step described below.

[0065] Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 22 is removed (first removal step). In the first removal step, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0066] Next, the remaining photoresist film is removed. Finally, the etching stopper film 21 is removed using the second light-shielding film 22 that was not removed in the first removal step as a mask (etching stopper film removal step). As a result, as shown in Figures 21 and 22, a photomask can be produced in which a new light-shielding region is added by the second light-shielding film 22 while the first pattern originally formed on the photomask 10 by the first light-shielding film 11 and the semi-transparent film 13 remains.

[0067] <Variation 5> In this modification, a pattern correction method will be described in which correction is performed to add a light-shielding region as described in the first embodiment, and correction is performed to reduce the size of a light-shielding region originally formed on the photomask. Fig. 23 is an enlarged view of one pattern formation region A on the photomask 10 that is the target of pattern correction in this modification. Figs. 24 and 25 are views for explaining the pattern correction method in this modification. Each of Figs. 24 and 25 corresponds to the cross-sectional view taken along the arrow HH in Fig. 23.

[0068] As shown in FIG. 23, a T-shaped first pattern is formed by a first light-shielding film 11 in a pattern formation region A of a photomask 10 to be repaired in this modification.

[0069] In the pattern correction method of this modified example, as shown in FIG. 24, a photomask 10 is prepared in which a pattern (first pattern) is formed on a transparent substrate 2 by a first light-shielding film 11 (step S21). Next, an etching stopper film 21 and a second light-shielding film 22 (second pattern formation portion) containing the first material are formed in this order on the surface of the photomask 10 on which the first pattern is formed (step S22, film formation step). Thereafter, a photoresist film 23 is formed on the entire surface of the photomask 10 including the second light-shielding film 22 (step S23, photoresist film formation step). In other words, the photoresist film 23 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22.

[0070] Next, a photoresist pattern is formed by drawing on the photoresist film 23 using a drawing device and then developing it (step S24, pattern formation step). Specifically, the photoresist pattern is formed so that only the photoresist film 23 remains in the area where a new light-shielding area is to be added and in the area of the light-shielding area by the first light-shielding film 11 that will remain as a light-shielding area even after the pattern correction. In this modification, the photoresist film 23 is removed in the area that is originally a light-shielding area by the first light-shielding film 11 and that is to be changed to a light-transmitting area. In other words, when the photomask 10 is viewed in plan, the photoresist pattern is formed so as to remove at least the first light-shielding film 11 and a portion of the photoresist film 23 that overlaps with the etching stopper film 21 and the second light-shielding film 22 formed in step S22.

[0071] Next, using the photoresist pattern formed in step S24 as a mask, a part of the second light-shielding film 22 is removed (step S25, first removal step). In step S25, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0072] 25, using the photoresist pattern formed in step S24 as a mask, a portion of the etching stopper film 21 is removed (step S26). Next, using the photoresist pattern formed in step S24 as a mask, a portion of the first light-shielding film 11 is removed (step S27, second removal step). Finally, the remaining photoresist film 23 is removed (step S28).

[0073] Fig. 26 is a plan view of the photomask after repairing it by the above method. In Fig. 26, the first light-shielding film 11 before repairing is indicated by a dashed line. As shown in Fig. 26, by repairing it by the above method, a new light-shielding region is added by the second light-shielding film 22, and the light-shielding region originally formed by the first light-shielding film 11 can be reduced in size when the photomask is viewed in plan.

[0074] The pattern repair method in this modified example can also be applied to the case where the first pattern is made of a phase shift film.

[0075] <Variation 6> In this modification, a pattern correction method for correcting the top-type photomask described in modification 1 by adding a light-shielding region and by reducing the size of the first pattern originally formed on the photomask will be described with reference to Figures 27 and 28. Figures 27 and 28 are diagrams for explaining the pattern correction method in this modification.

[0076] 27, in the pattern repair method of this modified example, first, a photomask 10 is prepared in which a pattern (first pattern) is formed on a transparent substrate 2 using a first light-shielding film 11 and a semi-transparent film 13 (step S31). Next, an etching stopper film 21 and a second light-shielding film 22 (second pattern formation portion) containing the first material are formed in this order on the surface of the photomask 10 on which the first pattern is formed (step S32, film formation step). Thereafter, a photoresist film 23 is formed on the entire surface of the photomask 10, including the second light-shielding film 22 (step S33, photoresist film formation step). In other words, the photoresist film 23 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22.

[0077] Next, a photoresist pattern is formed by drawing on the photoresist film 23 using a drawing device and then developing it (step S34, pattern formation step). Specifically, the photoresist pattern is formed so that only the photoresist film 23 remains in the area where a new light-shielding area is to be added, the area of the light-shielding area by the first light-shielding film 11 that will remain as a light-shielding area even after the pattern correction, and the area that was a semi-transparent area by the semi-transparent film 13 and that is to be changed to a light-shielding area. In this modification, the photoresist film 23 is removed in the area that is originally a light-shielding area or a semi-transparent area by the first light-shielding film 11 or the semi-transparent film 13 and that is to be changed to a transparent area. In other words, when the photomask 10 is viewed in plan, the photoresist pattern is formed so as to remove at least the first light-shielding film 11, the semi-transparent film 13, and a portion of the photoresist film 23 that overlaps with the etching stopper film 21 and the second light-shielding film 22 formed in step S32.

[0078] Next, using the photoresist pattern formed in step S34 as a mask, a part of the second light-shielding film 22 is removed (step S35, first removal step). In step S35, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0079] 28, the photoresist pattern formed in step S34 is used as a mask to remove a portion of the etching stopper film 21 (step S36). Next, the photoresist pattern formed in step S34 is used as a mask to remove a portion of the semi-transparent film 13 (step S37, second removal step). Next, the photoresist pattern formed in step S34 is used as a mask to remove a portion of the first light-shielding film 11 (step S38, third removal step). Finally, the remaining photoresist film 23 is removed (step S39).

[0080] By the above method, a new light-shielding region can be added by the second light-shielding film 22, the light-shielding region originally formed by the first light-shielding film 11 can be reduced when the photomask is viewed in plan, and part of the semi-transparent region formed by the semi-transparent film 13 can be changed to a light-shielding region. However, in this modification, the semi-transparent effect possessed by the photomask 10 before the repair is lost.

[0081] <Variation 7> In this modified example, a pattern correction method is described with reference to Figures 29 and 30, in which a bottom-type photomask described in Modification Example 3 is modified to add a light-shielding area and also modified to reduce the size of the first pattern originally formed on the photomask.

[0082] 29, in the pattern correction method of this modified example, first, a photomask 10 is prepared, in which a pattern (first pattern) is formed on a transparent substrate 2 using a first light-shielding film 11, a semi-transparent film 13, and an etching stopper film 14 (step S41). Next, an etching stopper film 21 and a second light-shielding film 22 (second pattern formation portion) containing the first material are formed in this order on the surface of the photomask 10 on which the first pattern is formed (step S42, film formation step). Thereafter, a photoresist film 23 is formed on the entire surface of the photomask 10, including the second light-shielding film 22 (step S43, photoresist film formation step). In other words, the photoresist film 23 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22.

[0083] Next, a photoresist pattern is formed by drawing on the photoresist film 23 using a drawing device and then developing it (step S44, pattern formation step). Specifically, the photoresist pattern is formed so that only the photoresist film 23 remains, corresponding to a region where a new light-shielding region is to be added, a region of the light-shielding region by the first light-shielding film 11 that will remain as a light-shielding region even after the pattern correction, and a region that was a semi-transparent region by the semi-transparent film 13 and that is to be changed to a light-shielding region. In this modification, the photoresist film 23 is removed from a region that is originally a light-shielding region or a semi-transparent region by the first light-shielding film 11 or the semi-transparent film 13 and that is to be changed to a transparent region. In other words, when the photomask 10 is viewed in plan, the photoresist pattern is formed so as to remove at least the first light-shielding film 11, the semi-transparent film 13, and a portion of the photoresist film 23 that overlaps with the etching stopper film 21 and the second light-shielding film 22 formed in step S42.

[0084] Next, using the photoresist pattern formed in step S44 as a mask, a part of the second light-shielding film 22 is removed (step S45, first removal step). In step S45, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0085] Next, as shown in FIG. 30, the photoresist pattern formed in step S44 is used as a mask to remove a portion of the etching stopper film 21 (step S46, etching stopper film removal step). Next, the photoresist pattern formed in step S44 is used as a mask to remove a portion of the first light-shielding film 11 (step S47, second removal step). Next, the photoresist pattern formed in step S44 is used as a mask to remove a portion of the etching stopper film 14 (step S48, third removal step). Next, the photoresist pattern formed in step S44 is used as a mask to remove a portion of the semi-transparent film 13 (step S49, fourth removal step). Finally, the remaining photoresist film 23 is removed (step S50).

[0086] By the above method, a new light-shielding region can be added by the second light-shielding film 22, the light-shielding region originally formed by the first light-shielding film 11 can be reduced when the photomask is viewed in plan, and part of the semi-transparent region formed by the semi-transparent film 13 can be changed to a light-shielding region. However, in this modification, the semi-transparent effect possessed by the photomask 10 before the repair is lost.

[0087] <Variation 8> In this modified example, a pattern correction method is described with reference to Figures 31 and 32, in which a bottom-type photomask described in modified example 4 is modified to add a light-shielding area and also modified to reduce the size of the first pattern originally formed on the photomask.

[0088] In the pattern correction method of this modified example, as shown in FIG. 31, a photomask 10 is prepared in which a pattern (first pattern) is formed on a transparent substrate 2 using a first light-shielding film 11 and a semi-transparent film 13 (step S51). Next, an etching stopper film 21 and a second light-shielding film 22 (second pattern formation portion) containing the first material are formed in this order on the surface of the photomask 10 on which the first pattern is formed (step S52, film formation step). Thereafter, a photoresist film 23 is formed on the entire surface of the photomask 10, including the second light-shielding film 22 (step S53, photoresist film formation step). In other words, the photoresist film 23 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 22.

[0089] Next, a photoresist pattern is formed by drawing on the photoresist film 23 using a drawing device and then developing it (step S54, pattern formation step). Specifically, the photoresist pattern is formed so that only the photoresist film 23 remains in the area where a new light-shielding area is to be added, the area of the light-shielding area by the first light-shielding film 11 that will remain as a light-shielding area even after the pattern correction, and the area that was a semi-transparent area by the semi-transparent film 13 and that is to be changed to a light-shielding area. In this modification, the photoresist film 23 is removed in the area that is originally a light-shielding area or a semi-transparent area by the first light-shielding film 11 or the semi-transparent film 13 and that is to be changed to a transparent area. In other words, when the photomask 10 is viewed in plan, the photoresist pattern is formed so as to remove at least the first light-shielding film 11, the semi-transparent film 13, and parts of the photoresist film 23 that overlap with the etching stopper film 21 and the second light-shielding film 22 formed in step S52.

[0090] Next, using the photoresist pattern formed in step S54 as a mask, a part of the second light-shielding film 22 is removed (step S55, first removal step). In step S55, a solvent that does not dissolve the etching stopper film 21 is used as a solvent for etching the second light-shielding film 22, so that only the second light-shielding film 22 is etched and removed.

[0091] Next, as shown in FIG. 32, the photoresist pattern formed in step S54 is used as a mask to remove a portion of the etching stopper film 21 (step S56, etching stopper film removal step). Next, the photoresist pattern formed in step S54 is used as a mask to remove a portion of the first light-shielding film 11 (step S57, second removal step). Next, the photoresist pattern formed in step S54 is used as a mask to remove a portion of the semi-transparent film 13 (step S58, third removal step). Finally, the remaining photoresist film 23 is removed (step S59).

[0092] By the above method, a new light-shielding region can be added by the second light-shielding film 22, the light-shielding region originally formed by the first light-shielding film 11 can be reduced when the photomask is viewed in plan, and part of the semi-transparent region formed by the semi-transparent film 13 can be changed to a light-shielding region. However, in this modification, the semi-transparent effect possessed by the photomask 10 before the repair is lost.

[0093] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0094] In the first embodiment, a pattern repair method was described in which a new light-shielding portion is formed by the second light-shielding film 22 on a photomask on which a pattern has already been formed by the first light-shielding film 11. In contrast, the pattern repair method of the present embodiment will be described as a method in which a new transmissive portion is formed on a photomask on which a pattern has been formed by forming a transmissive portion in the light-shielding film.

[0095] Fig. 33 is a plan view showing the configuration of a photomask 30 as an example of a photomask whose pattern is to be corrected by the pattern correction method of this embodiment. Fig. 34 is an enlarged view of region D4 shown in Fig. 33, that is, an enlarged view of one pattern formation region A.

[0096] 33, the photomask 30 has a plurality of pattern formation regions A formed on a transparent substrate 2. In the pattern formation regions A, as shown in Fig. 34, a light-shielding film 41 is formed on the transparent substrate 2, and light-transmitting portions 42 are patterned in the light-shielding film 41. In this embodiment, an example will be described in which a circular light-transmitting portion 42 is formed in one pattern formation region A.

[0097] 35 is a diagram showing a portion of a pattern to be corrected by the pattern correction method of this embodiment. In this embodiment, an example will be described in which the pattern is corrected so that a new light-transmitting portion is formed in region D5 located at the center of the circle formed by light-transmitting portion 42, as shown in FIG.

[0098] Fig. 36 is a flowchart showing an example of a pattern repair method according to this embodiment. Fig. 37 is a diagram for explaining the pattern repair method according to this embodiment. As shown in Fig. 36 and Fig. 37, in the pattern repair method according to this embodiment, first, a photomask 30 is prepared on which a pattern has already been formed by patterning a light-transmitting portion 42 in a light-shielding film 41 (step S11).

[0099] Next, a photoresist film 51 is formed on the surface of the photomask 30 on which the pattern is formed (step S12). Next, a pattern is drawn on the photoresist film 51 using a drawing device, and then developed to form a photoresist pattern (step S13). Specifically, the photoresist pattern is formed so that only the light-shielding film 41 corresponding to the region D5 shown in FIG. 35 is removed in step S14, which will be described later.

[0100] In step S13 of this embodiment, the photomask 30 is positioned using the alignment marks 4 formed in advance on the transparent substrate 2 of the photomask 30 as a reference, and then drawing is performed using a drawing device. This makes it possible to control the positions at which newly added transparent portions are added with high precision. Note that if precision in the positions at which the additional transparent portions are formed is not required, there is no need to position the photomask 30 using the alignment marks 4.

[0101] Next, using the photoresist pattern formed in step S13 as a mask, a part of the light-shielding film 41 is removed (step S14), thereby forming a new light-transmitting portion 45.

[0102] Finally, the remaining photoresist film 51 is removed (step S15), thereby producing a photomask on which new light-transmitting portions 45 are formed in addition to the pre-formed light-transmitting portions 42.

[0103] In the above-described embodiments, the pattern is corrected using a positive photoresist film, but the present invention is not limited to this. In one aspect of the present invention, the pattern may be corrected using a negative photoresist film.

[0104] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0105] 2 Transparent substrate 4 Alignment marks 10 Photomask 11 First light-shielding film (first pattern forming portion) 13 Semi-transparent film (first pattern forming portion) 14, 21 Etching stopper film 21 Etching stopper film 22 second light-shielding film (second pattern forming portion) 23 Photoresist film

Claims

1. 1. A pattern repair method for repairing a photomask on which a pattern has already been formed by a first pattern forming unit including a first material on a transparent substrate, into a pattern in which a function of at least a part of a region is different from that of the pattern, comprising: a film formation step of forming an etching stopper film and a second pattern formation portion containing a second material of the same metal system as the first material in this order on the surface of the photomask on which the pattern is formed; a photoresist film forming step of forming a photoresist film on a surface of the photomask so as to cover the entire surface of the second pattern formation portion; a pattern forming step of forming a photoresist pattern on the photoresist film by using a drawing device; a first removing step of removing a part of the second pattern forming portion using the photoresist pattern as a mask; an etching stopper film removing step of removing the second pattern formation portion that was not removed in the first removing step or the etching stopper film using the photoresist pattern as a mask, the change in the function of the at least some of the regions includes a change from a phase-shifting function to a semi-transparent function; the first pattern formation portion and the second pattern formation portion include a phase shift film, In the pattern forming step, the photoresist pattern is formed so as to leave at least a portion of the photoresist film in a region overlapping with the first pattern formation portion.

2. A pattern modification method as described in claim 1, wherein in the pattern formation process, the photoresist pattern is formed so as to leave the photoresist film in the entire area overlapping with the phase shift film of the first pattern formation portion, and in the area adjacent to the phase shift film of the first pattern formation portion when the photomask is viewed in a plane.

3. 3. The pattern repair method according to claim 1, wherein the first material and the second material are a Cr-based metal compound, a Si-based compound, or a metal silicide compound.

4. 4. The pattern correction method according to claim 1, wherein in the pattern formation step, the drawing device draws on the photoresist film using an alignment mark that is formed on the transparent substrate simultaneously when the first pattern formation unit forms the pattern.

5. 4. The pattern modification method according to claim 1, wherein the photoresist pattern is formed in the pattern formation step so that, when the photomask is viewed in a plane, a part of the second pattern formation portion that was not removed in the first removal step is not adjacent to the first pattern formation portion.

6. A photomask in which a new pattern is added to a photomask in which a first pattern has already been formed by a first pattern forming portion including a first material on a transparent substrate, the first pattern; a second pattern formed on the transparent substrate by an etching stopper film and a second pattern formation portion including a second material of the same metal system as the first material; the first pattern formation portion and the second pattern formation portion include a phase shift film, A photomask having an area where the phase shift film of the first pattern forming portion and the phase shift film of the second pattern forming portion overlap, thereby changing at least a part of the phase shift function that the photomask had before the pattern was newly added to a semi-transparent function.

7. The phase shift film of the second pattern forming portion is superimposed on the side of the phase shift film of the first pattern forming portion opposite to the transparent substrate, 7. The photomask according to claim 6, wherein the phase shift film of the second pattern formation portion is formed in a region adjacent to the phase shift film of the first pattern formation portion when the photomask is viewed in plan view.

Images