TWI833314B - Pattern modification method, and photomask - Google Patents

Abstract

The purpose of the present invention is to perform large-scale pattern correction in one go. A pattern correction method according to one aspect of the present invention corrects a new pattern on a photomask (10) that has been patterned using a first light-shielding film (11) containing a first material, and includes the following steps: film formation a step of forming a second light-shielding film (21) containing a second material different from the first material; a photoresist film forming step of forming a photoresist film (22) to cover the entire second light-shielding film (21) surface; a pattern forming step to form a photoresist pattern; and a light-shielding film removal step to use the photoresist pattern as a mask and use an etching solution that dissolves the second material but does not dissolve the first material to remove the second light-shielding film. part of the membrane (21).

Description

Pattern correction method and photomask

The present invention relates to a pattern correction method for correcting the pattern of a patterned photomask.

The conventional technology discloses a technology, such as a technology for correcting the pattern of a photomask that is already in use (that is, a photomask that has been patterned). By correcting the pattern of the photomask on which the pattern has been formed, a desired photomask can be produced more cheaply than making a new photomask. As such a technology, for example, Japanese Patent Document 1 discloses a technology for correcting the pattern of a photomask using CVD (Chemical Vapor Deposition).

[Patent Document]

Patent Document 1: Japanese Patent Application Laid-Open No. 2-140744

However, in the technology described in Japanese Patent Document 1, the area that can be corrected at one time is as small as tens of μm×tens of μm. Therefore, there is a problem that it takes time to perform large-scale pattern correction.

An object of one aspect of the present invention is to realize a pattern correction method capable of performing large-scale pattern correction at once.

In order to solve the above-mentioned problems, a pattern correction method according to one aspect of the present invention corrects a new pattern on a photo mask (photo mask) on which a pattern has already been formed on a transparent substrate using a first pattern forming portion containing a first material. Contains the following steps: The film forming step is to form a second pattern forming part on the surface of the photomask on which the pattern is formed; the photoresist film forming step is to form a photoresist film on the surface of the photomask to cover the photoresist film. the entire surface of the second pattern forming part; a pattern forming step of drawing and forming a photoresist pattern on the photoresist film using a drawing device; and a first removal step of using the photoresist pattern as a mask to remove the first 2. Part of the pattern forming part.

According to one aspect of the present invention, large-scale pattern correction can be performed at once.

2:Transparent substrate

4: Calibration mark

10, 30: Photomask

11: 1st light-shielding film (1st pattern forming part)

13: Semi-permeable membrane (first pattern forming part)

20: Etching stop film

21: Second light-shielding film (second pattern forming part)

22: Photoresist film

FIG. 1 is a plan view showing an example of a photomask whose pattern is corrected using the pattern correction method according to the first embodiment of the present invention.

Fig. 2 is an enlarged view showing the area D1 shown in Fig. 1 .

FIG. 3 is a diagram showing a portion of the pattern to be corrected according to the pattern correction method of the first embodiment of the present invention.

FIG. 4 is a flowchart showing an example of the pattern correction method according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining the pattern correction method according to the first embodiment of the present invention.

FIG. 6 is a diagram showing the pattern formation area A after correction using the pattern correction method according to the first embodiment of the present invention.

FIG. 7 is an enlarged view of a pattern formation region in the photomask that is a target of pattern correction in a modification of the first embodiment.

Figure 8 is a cross-sectional view along line A-A shown in Figure 7.

Fig. 9 is a diagram showing a pattern formation area after the pattern has been corrected using the pattern correction method of the above modification.

Figure 10 is a cross-sectional view along line B-B shown in Figure 9.

FIG. 11 is a diagram showing another example of the pattern formation area after the pattern has been corrected using the pattern correction method of the above modification.

FIG. 12 is a diagram showing another example of the pattern formation area after the pattern has been corrected using the pattern correction method of the above modification.

FIG. 13 is an enlarged view of a pattern formation region in a photomask that is a target of pattern correction in another modification of the first embodiment.

Figure 14 is a cross-sectional view along line C-C shown in Figure 13.

FIG. 15 is a diagram showing a pattern formation area after the pattern has been corrected using the pattern correction method of the above modification.

Fig. 16 is a cross-sectional view along line E-E shown in Fig. 15.

FIG. 17 is a diagram for explaining another pattern correction method according to the above modified example.

Fig. 18 is a diagram for explaining another pattern correction method according to the above modification.

FIG. 19 is an enlarged view of a pattern formation region in a photomask that is a target of pattern correction in another modification of the first embodiment.

Figure 20 is a cross-sectional view along line F-F shown in Figure 19.

Fig. 21 is a diagram showing a pattern formation area after the pattern has been corrected using the pattern correction method of the above modification.

Figure 22 is a cross-sectional view along line G-G shown in Figure 21.

FIG. 23 is an enlarged view of a pattern formation region in a photomask that is a target of pattern correction in another modification of the first embodiment.

Fig. 24 is a diagram for explaining the pattern correction method in the above modification.

Fig. 25 is a diagram for explaining the pattern correction method in the above modification.

Fig. 26 is a plan view of the photomask corrected by the pattern correction method in the above modification.

Fig. 27 is a diagram for explaining a pattern correction method in another modification of the first embodiment.

Fig. 28 is a diagram for explaining the pattern correction method in the above modification.

Fig. 29 is a diagram for explaining a pattern correction method in another modification of the first embodiment.

Fig. 30 is a diagram for explaining the pattern correction method in the above modification.

Fig. 31 is a diagram for explaining a pattern correction method in another modification of the first embodiment.

Fig. 32 is a diagram for explaining the pattern correction method in the above modification.

FIG. 33 is a plan view showing an example of a photomask whose pattern is corrected using the pattern correction method according to the second embodiment of the present invention.

Fig. 34 is an enlarged view showing the area D4 shown in Fig. 33.

Fig. 35 is a diagram showing a portion where the pattern is to be corrected using the pattern correction method according to the second embodiment of the present invention.

FIG. 36 is a flowchart showing an example of a pattern correction method according to the second embodiment of the present invention.

Fig. 37 is a diagram for explaining the pattern correction method according to the second embodiment of the present invention.

FIG. 38 is a flowchart showing an example of a pattern correction method according to the third embodiment of the present invention.

Fig. 39 is a diagram for explaining the pattern correction method according to the third embodiment of the present invention.

Fig. 40 is a diagram showing a pattern formation area after a pattern has been corrected using a pattern correction method according to a modification of the third embodiment.

Figure 41 is a cross-sectional view along line B-B shown in Figure 40.

FIG. 42 is a diagram showing another example of the pattern formation area after the pattern has been corrected using the pattern correction method of the above modification.

FIG. 43 is a diagram showing another example of the pattern formation area after the pattern has been corrected using the pattern correction method of the above modification.

Fig. 44 is a diagram showing a pattern formation area after the pattern has been corrected using a pattern correction method according to another modification of the third embodiment.

Fig. 45 is a cross-sectional view along line E-E shown in Fig. 44.

Fig. 46 is a diagram for explaining another pattern correction method according to the above modification.

Fig. 47 is a diagram for explaining another pattern correction method according to the above modification.

Fig. 48 is a diagram showing a pattern formation area after the pattern has been corrected using a pattern correction method according to another modification of the third embodiment.

Figure 49 is a cross-sectional view along line G-G shown in Figure 48.

Fig. 50 is a diagram for explaining a pattern correction method in another modification of the third embodiment.

Fig. 51 is a diagram for explaining the pattern correction method in the above modification.

Fig. 52 is a plan view showing a photomask corrected by the pattern correction method in the above modification.

Fig. 53 is a diagram for explaining a pattern correction method in another modification of the third embodiment.

Fig. 54 is a diagram for explaining the pattern correction method in the above modification.

Fig. 55 is a diagram for explaining a pattern correction method in another modification of the third embodiment.

Fig. 56 is a diagram for explaining the pattern correction method in the above modification.

Fig. 57 is a diagram for explaining a pattern correction method in another modification of the third embodiment.

Fig. 58 is a diagram for explaining the pattern correction method in the above modification.

[First Embodiment]

Below, an embodiment of the present invention will be described in detail. In this embodiment, an example of a pattern correction method for correcting the pattern of a photomask in which a pattern is formed using a light-shielding film on a transparent substrate is explained. In this specification, the so-called "patterned photomask" refers to a photomask with a pattern formed on a transparent substrate, which is manufactured as a one-time finished product through a series of manufacturing steps. For example, it may also be already in use. photomask.

FIG. 1 is a plan view showing the structure of a photomask 10 as an example of a photomask to be corrected by the pattern correction method of this embodiment. Figure 2 shows the area shown in Figure 1 An enlarged view of D1, which is an enlarged view of pattern forming area A.

As shown in FIG. 1 , the photomask 10 forms a plurality of pattern forming areas A on the transparent substrate 2 . The transparent substrate 2 is composed of a substrate such as synthetic quartz glass. The transparent substrate 2 has a transmittance of 95% or more for the representative wavelength included in the exposure light in the exposure step. The representative wavelength of the above-mentioned exposure light may be, for example, i-line, h-line, or g-line, or a mixture of these, but is not limited to these.

In the pattern formation area A, as shown in FIG. 2 , a first light-shielding film 11 (first pattern) containing an opaque (that is, light-shielding) material (hereinafter referred to as the first material) is formed on the transparent substrate 2 . forming part) to form a pattern (hereinafter also referred to as the first pattern). The optical density OD value of the first light-shielding film 11 is preferably 2.7 or more, and for example, a chromium film can be used. In order to prevent the generation of diffuse light during exposure, an antireflection film may be laminated on both surfaces of the first light-shielding film 11 to form an antireflection film.

In the pattern formation area A, the area where the first light-shielding film 11 is not formed becomes the light-transmitting portion 12 that transmits light. In this embodiment, an example in which the circular first light-shielding film 11 is formed on one pattern formation area A will be described. On the photomask 10, as shown in Figure 1, when the first light-shielding film 11 is patterned on the photomask 10, alignment marks 4 are formed at the four corners of the transparent substrate 2, and the alignment marks 4 serve as positioning The photomask 10 is set as a reference.

Fig. 3 is a diagram showing a portion where the pattern is to be corrected using the pattern correction method in this embodiment. In this embodiment, as shown in FIG. 3 , in order to correct the pattern, the area D2 adjacent to the inside of the circle formed by the first light-shielding film 11 and the area D2 located in the center of the circle and not connected with the first light-shielding film 11 will be explained. An example in which a new light shielding portion is formed in the adjacent area D3. In this embodiment, one pattern forming area A will be described, but for other pattern forming areas A, each pattern may be corrected as necessary.

FIG. 4 is a flowchart showing an example of the pattern correction method in this embodiment. Fig. 5 is a diagram for explaining the pattern correction method in this embodiment. Each figure shown in FIG. 5 is a cross-sectional view cut on a plane perpendicular to the surface of the transparent substrate 2 through the center of the circle formed by the first light-shielding film 11 . As shown in Figures 4 and 5, in the pattern correction method in this embodiment, first, a photomask 10 with a first pattern formed on the transparent substrate 2 is prepared using the first light-shielding film 11 (step S1 ).

Next, a second light-shielding film 21 (second pattern forming portion) containing a material different from the first material (hereinafter referred to as the second material) is formed on the entire surface of the photomask 10 on which the first pattern is formed ( Step S2, film forming step). In this specification, the pattern correction method of the present invention is used when correcting a pattern. Among them, the member used as a pattern of a photomask after correction is called a "second pattern forming part". The second light-shielding film 21 is formed by, for example, sputtering, evaporation, or the like.

Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S3, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 . The photoresist film 22 is formed by, for example, a coating method, a spray coating method, or the like. The second material is a material that has a different solubility from the first material in a given etching solution. In this specification, materials having different solubilities in a given etching solution are called materials with selective etching properties. For example, when the first light-shielding film 11 is composed of a Cr film, as the second light-shielding film 21 , a Ni film, a Ti film, a MoSi film, or the like having selective etching properties with the Cr film can be used.

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S4, pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 in the region corresponding to the region D2 and the region D3 shown in FIG. 3 will not be removed in the first removal step described below. Development can be performed using a paddle method, a dipping method, a spraying method, a rotation method, or the like.

In step S4 of this embodiment, the photomask 10 is positioned based on the calibration mark 4 formed at the same time when the first pattern is formed by the first light-shielding film 11 on the transparent substrate 2 of the photomask 10 , and draw it with a drawing device. In other words, using the calibration mark 4 as a reference, the drawing device is used to draw on the photoresist film 22 . Thereby, the additional position of the newly added light shielding part can be controlled with high precision. In addition, when there is no need to increase the accuracy of the formation position of the light shielding portion, there is no need to use a calibration mark. Mark 4 to position the photomask 10 .

Next, using the photoresist pattern formed in step S4 as a mask, a part of the second light-shielding film 21 is removed (step S5, first removal step). In step S5, an etching liquid that dissolves the second material but does not dissolve the first material is used. Thereby, in the area where there is no photoresist mask, only the second light-shielding film 21 is removed without removing the first light-shielding film 11 . As a result, additional patterning can be performed using the second light-shielding film 21 while leaving the first light-shielding film 11 originally formed on the photomask 10 . In addition, dry etching may be used to remove a part of the second light-shielding film 21 .

Finally, the remaining photoresist film 22 is removed (step S6). Thereby, a photomask in which a new light-shielding portion is added using the new second light-shielding film 21 can be produced. The photoresist film 22 can be removed by, for example, stirring, ashing, or immersing in a photoresist stripping solution.

FIG. 6 is a diagram showing the pattern formation area A after correction using the pattern correction method in this embodiment. As shown in FIG. 6 , in the pattern formation area A after pattern correction, the second light-shielding film 21 is formed in the area D2 and the area D3 shown in FIG. 3 . By forming the second light-shielding film 21 in the region D2, the area of the light-shielding region formed by the first light-shielding film 11 before pattern correction can be enlarged. In other words, when the photomask 10 is viewed from above, the width of the light-shielding region formed by the first light-shielding film 11 can be enlarged. In addition, by forming the second light-shielding film 21 on the area D3, a light-shielding area can be additionally formed.

As described above, in the pattern correction method in this embodiment, the second light-shielding film 21 having selective etching properties different from the first light-shielding film 11 is formed on the entire surface of the existing photomask 10, and yellow light lithography is used. The second light-shielding film 21 is patterned using a photolithography method. With this structure, the second light-shielding film 21 can be additionally patterned on the entire surface of the photomask 10 . That is, the pattern correction method in this embodiment can perform large-scale pattern correction at one time. As a result, the patterned photomask pattern can be pattern corrected in a short time.

In addition, with the pattern correction method in this embodiment, the film peeling phenomenon that occurs when CVD is used as in the technology of Japanese Patent Document 1 does not occur. In addition, in the case of using CVD, by When the laser light is irradiated to areas other than the desired area, the light-shielding portion is also formed outside the desired area. Therefore, it is necessary to remove the light-shielding portion while shaping. In contrast, in the pattern correction method of this embodiment, since a drawing device is used to form the pattern of the second light-shielding film 21, the pattern can be added with high accuracy without removing unnecessary light-shielding portions.

In the pattern correction method in this embodiment, in step S4 (pattern forming step), after positioning the photomask 10 with the calibration mark 4 as a reference, drawing is performed with a drawing device. However, the alignment mark 4 is sometimes not formed on the photomask 10 . In this case, the photomask 10 can also be positioned in the following manner.

First, before step S3 (photoresist film forming step), alignment marks are formed on the second light-shielding film 21 . Then, the positional relationship and tilt deviation between the produced calibration mark and the object pattern originally formed on the photomask 10 before correction is determined, and then based on the positional relationship and deviation, the drawing position of the drawing device in step S4 is calculated. Correction. The target pattern is not particularly limited as long as the position formed on the photomask 10 before correction is known. For example, a calibration mark for transfer exposure, a mark for length measurement, etc. may be used.

According to this structure, even when the calibration mark 4 is not formed on the photomask 10, the newly produced calibration mark can be used to correct the position drawn by the drawing device, so the additional pattern can be formed with high accuracy.

The photomask corrected according to the pattern correction method in this embodiment is a photomask in which a first pattern has been formed on the transparent substrate 2 using the first light-shielding film 11 and a new pattern is added, and has: (1) The above-mentioned first pattern; (2) a pattern formed adjacent to the first pattern on the transparent substrate 2 when the photomask is viewed from above, in which the second light-shielding film 21 contains a second material different from the first material. The pattern of the light-shielding area formed (second pattern); (3) a pattern formed not adjacent to the first pattern when the photomask is viewed from above, wherein the pattern is formed of the second light-shielding film 21 containing the second material (2nd pattern).

<Modification 1>

In the first embodiment, the pattern correction method of newly forming the light-shielding portion formed of the second light-shielding film 21 on the photomask on which the first pattern has been previously formed using the first light-shielding film 11 has been described. However, the present invention It is not limited to this. In one aspect of the present invention, a photomask in which the first pattern is formed of a film other than a light-shielding film can be used. Detailed description will be given with reference to Figures 7 to 10.

FIG. 7 is an enlarged view of one pattern formation area A in the photomask 10 that is the object of pattern correction in this modification. Figure 8 is a cross-sectional view along line A-A shown in Figure 7. The photomask 10 to be corrected in this modification is a top type photomask. Fig. 9 is a diagram showing the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. Figure 10 is a cross-sectional view along line B-B shown in Figure 9.

The photomask 10 used as the pattern correction target in this modification example is composed of the first light-shielding film 11 serving as the first pattern forming portion and the irradiated film in the pattern forming area A as shown in FIGS. 7 and 8 . The semi-transmissive film 13 that partially transmits light forms a pattern (first pattern). More specifically, as shown in FIG. 8 , the first light-shielding film 11 is formed on a part of the pattern formation area A, and the semi-transmissive film 13 is formed on a layer opposite to the transparent substrate 2 side of the first light-shielding film 11 . And on a part of the area in the pattern formation area A where the first light-shielding film 11 is not formed. In other words, the semi-transmissive film 13 is formed on a part of the pattern formation area A, and the first light-shielding film 11 is arranged on a part between the semi-transmissive film 13 and the transparent substrate 2 . With this structure, the photomask 10 as a pattern correction target becomes a half-tone mask. When the photomask 10 is viewed from above, the area where the semi-transmissive film 13 and the first light-shielding film 11 overlap becomes a light-shielding area. Only the area of the semipermeable membrane 13 is a semipermeable area.

The first light-shielding film 11 and the semi-permeable film 13 are made of the same metal material. In other words, the first light-shielding film 11 and the semi-permeable film 13 are made of materials containing the same metal. For example, the first light-shielding film 11 is made of chromium, chromium oxide, or the like, and the semi-permeable film 13 is made of chromium, chromium oxide, or the like.

Next, a pattern correction method of the photomask 10 having the above-described structure will be described. First, on the surface of the photomask 10 on which the first pattern is formed, a first light-shielding film 11 composed of The second light-shielding film 21 is made of a metal material (second material) different from the metal contained in the material of the semipermeable film 13 (film forming step).

Next, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (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 21 .

Next, a drawing device is used to draw on the photoresist film, and then a photoresist pattern is formed using a drawing device (pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 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.

Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 21 is removed (first removal step). In the first removal step, an etching liquid that dissolves the second material but does not dissolve the materials constituting the first light-shielding film 11 and the semipermeable film 13 is used. Thereby, only the second light-shielding film 21 is etched and removed. Finally, remove the remaining photoresist film.

Thereby, as shown in FIGS. 9 and 10 , a photomask can be produced that uses the second light-shielding film 21 to add a new light-shielding area while retaining the original light-shielding area formed by the first light-shielding film 11 and the semi-transmissive film 13 . The first pattern is formed on the photomask 10 .

FIG. 11 is a diagram showing another example of the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. As shown in FIG. 11 , in one aspect of the present invention, when the photomask 10 is viewed from above, a part of the second light-shielding film 21 and a part of the first pattern (more specifically, the first pattern is formed with a The second light-shielding film 21 is formed in an overlapping manner (part of the area of the light-shielding film 11). Therefore, the shape of the light-shielding area of the photomask 10 can be changed.

FIG. 12 is a diagram showing another example of the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. As shown in FIG. 12 , in one aspect of the present invention, when the photomask 10 is viewed from above, the second light-shielding film 21 may be formed to include the entire first pattern formed by the first light-shielding film 11 and the semi-transmissive film 13 . area. Thereby, the area of the light-shielding area of the photomask 10 can be enlarged. However, in this case In this case, the semi-transmissive effect of the photomask 10 before correction will disappear.

In addition, in this modification, the method of performing pattern correction on the photomask in which the pattern (first pattern) is formed using the first light-shielding film 11 and the semi-transmissive film 13 as the first pattern forming portion has been described. However, in this modification, According to one aspect of the invention, the same pattern correction can be performed on a photomask using a phase shift film instead of the first light-shielding film 11 .

<Modification 2>

Each of the above pattern correction methods can also be performed on a photomask in which the first pattern is formed of a phase shift film. The transmittance of the phase shift film is about 1 to 15%, and it is a semi-permeable film that has the effect of reversing (or shifting) the phase. The phase shift effect is used to improve the resolution. However, as shown in the example of FIG. 12 , when the photomask 10 is viewed from above, when the second light-shielding film 21 is formed in the entire area including the first pattern formed by the phase shift film, the photomask 10 before correction is Any phase shifting effect will disappear.

When correcting the photomask 10 in which the first pattern is formed of a phase shift film, the phase shift film may be used instead of the second light-shielding film 21 for correction. Thereby, the shape of the area having a phase shift effect can be changed. However, as shown in the example of FIG. 12 , when the photomask 10 is viewed from above, when the phase shift film is formed so as to include the entire area of the first pattern formed by the phase shift film, when the photomask 10 is viewed from above, , the phase shift effect will disappear in the area where the phase shift film overlaps, and it will become a photomask that can only obtain the phase shift effect in the area where the newly formed phase shift film exists (that is, an edge-enhanced photomask ).

<Modification 3>

In Modification 1, the method of correcting the pattern of the top-type halftone 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 halftone mask. For detailed instructions, please refer to Figures 13 to 16.

FIG. 13 is an enlarged view of one pattern formation area A in the photomask 10 that is the subject of pattern correction in this embodiment. Figure 14 is a cross-sectional view along line C-C shown in Figure 13. FIG. 15 is a diagram showing the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. No. Figure 16 is a cross-sectional view along line E-E shown in Figure 15.

The photomask 10 used as the pattern correction target in this modification example is composed of the first light-shielding film 11 serving as the first pattern forming portion and the irradiated film in the pattern forming area A as shown in FIGS. 13 and 14 The semi-transmissive film 13 that partially transmits light forms a pattern (first pattern). More specifically, as shown in FIG. 14 , the semipermeable film 13 is formed on a part of the pattern formation area A, and the etching stopper film 14 is sequentially laminated on a part of the layer of the semipermeable film 13 on the side opposite to the transparent substrate 2 side. and the first light-shielding film 11. With the above structure, when the photomask 10 is the object of pattern correction in this modification, when the photomask 10 is viewed from above, the area where the semi-transmissive film 13 and the first light-shielding film 11 overlap becomes a light-shielding area, and only the semi-transmissive film 13 The areas are formed as semi-transparent areas of the halftone mask. The semi-permeable film 13 and the first light-shielding film 11 are made of the same metal material.

Next, a pattern correction method of the photomask 10 having the above-described structure will be described. First, on the surface of the photomask 10 on which the first pattern is formed, a film is formed of a material containing a metal different from the metal contained in the materials constituting the first light-shielding film 11 and the semi-permeable film 13 (second material). The second light-shielding film 21 is formed (film forming step).

Next, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (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 21 .

Next, the photoresist film is drawn with a drawing device and then developed to form a photoresist pattern (pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 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.

Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 21 is removed (first removal step). In the first removal step, an etching liquid that dissolves the second material but does not dissolve the materials constituting the first light-shielding film 11 and the semipermeable film 13 is used. Thereby, only the second light-shielding film 21 is etched and removed. Finally, the remaining photoresist film is removed. Thereby, as shown in FIGS. 15 and 16 , a photomask can be produced, which uses the second light-shielding film 21 to add a new light-shielding area while retaining the first light-shielding film 11 and the semi-transparent area. The film 13 is originally formed on the first pattern on the photomask 10 .

Furthermore, in this modification, the method of performing pattern correction on a photomask in which a pattern (first pattern) is formed by the first light-shielding film 11 and the semi-transmissive film 13 as the first pattern forming portion has been described. However, in this modification, According to one aspect of the invention, pattern correction can be performed in the same manner on a photomask using a phase shift film instead of the first light-shielding film 11 . The phase shift film has the function of shifting the phase of the exposure light, and has the property of using a separate film to reverse the phase of the exposure light (that is, the phase shift angle is approximately 180°). However, "about 180°" here means 180°±20°, and refers to the phase difference of the exposure light that can fully obtain the interference effect of the exposure light.

In addition, in one aspect of the present invention, when pattern correction is performed on a photomask using a phase shift film instead of the first light-shielding film 11, a semi-transmissive film that partially transmits exposure light may be used instead of the second light-shielding film 21. . In this case, the transmittance of the phase shift film is preferably 3~15%. In addition, in one aspect of the present invention, in a photomask using a semi-transmissive film instead of the first light-shielding film 1, a phase shift film can be used instead of the second light-shielding film 21 to perform pattern correction. In this case, the semi-permeable film preferably has a transmittance of 10 to 70% and a phase shift angle of 0.1° to 20° relative to the exposure light.

Next, with reference to Figures 17 and 18, a new light-shielding area is added to the bottom-type half-tone photomask 10 shown in Figures 13 and 14, and at the same time, the first light-shielding film 11 is A pattern correction method in which a part of the light-blocking area is changed into a semi-transmissive area and is corrected will be described. Figures 17 and 18 are diagrams for explaining this pattern correction method. Each of the figures shown in Figures 17 and 18 is a cross-sectional view along line D-D shown in Figure 13.

In this pattern correction method, as shown in FIG. 17, a photomask 10 (first pattern) formed with a first light-shielding film 11, a semi-transmissive film 13, and an etching stopper film 14 is prepared on the transparent substrate 2. Step S11). Next, a second light-shielding film 21 (second pattern forming portion) containing the second material is formed on the surface of the photomask 10 on which the first pattern is formed (step S12, film forming step). Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S13, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is performed to form a photoresist pattern (step S14, pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 corresponding to the area to be changed to the light-shielding area is not removed in the first removal step described below.

Next, using the photoresist pattern formed in step S14 as a mask, a part of the second light-shielding film 21 is removed (step S15, first removal step). In step S15 , an etching liquid that dissolves the second material but does not dissolve the materials constituting the first light-shielding film 11 and the semipermeable film 13 is used. Thereby, only the second light-shielding film 21 is etched and removed.

Next, as shown in FIG. 18 , a part of the first light-shielding film 11 is removed using the photoresist pattern formed in step S14 as a mask (step S16 ). Then, using the photoresist pattern formed in step S14 as a mask, a part of the etching stopper film 14 is removed (step S17). Finally, the remaining photoresist film 22 is removed (step S19).

According to the above method, a new light-shielding area is added using the new second light-shielding film 21. At the same time, when the photomask is viewed from above, the semi-transmissive film 13 can be used to expose a portion of the first light-shielding film 11 that originally became the light-shielding area. Part of the light-blocking area is changed to a semi-transparent area.

<Modification 4>

In Modification 3, a modification is described in which the semi-permeable film 13 and the first light-shielding film 11 made of the same metal-based material and the etching stop film 14 arranged between the semi-permeable film 13 and the first light-shielding film 11 are modified. A bottom-type half-tone mask pattern method is used, but the present invention is not limited thereto. The pattern correction method according to one aspect of the present invention can also be applied to bottom-type halftone masks having other structures. For detailed instructions, please refer to Figures 19 to 22.

FIG. 19 is an enlarged view of a pattern forming area A in the photomask 10 that is the object of pattern correction in this embodiment. Figure 20 is a cross-sectional view along line F-F shown in Figure 19. Fig. 21 is a diagram showing the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. No. Figure 22 is a cross-sectional view along line G-G shown in Figure 21.

The photomask 10 used as a pattern correction target in this modification example is composed of a first light-shielding film 11 serving as a first pattern forming portion and a semi-transmissive film that transmits part of the irradiated light, as shown in FIGS. 19 and 20 13 to form a pattern (first pattern). More specifically, as shown in FIG. 20 , the semi-transmissive film 13 is formed on a part of the pattern formation area A, and the first light-shielding film 11 is laminated on the layer of the semi-transmissive film 13 on the side opposite to the transparent substrate 2 side. With the above structure, in the photomask 10 that is the subject of pattern correction in this modification, when the photomask 10 is viewed from above, the area where the semi-transmissive film 13 and the first light-shielding film 11 overlap becomes a light-shielding area, and only semi-transmissive film 10 is formed. The area of the film 13 is a half-tone mask that becomes a semi-transmissive area. The first light-shielding film 11 and the semi-permeable film 13 are made of different metal materials. For example, the first light-shielding film 11 is made of a Cr-based material, and the semi-permeable film 13 is made of MoSi as a third material.

Next, a pattern correction method of the photomask 10 having the above-described structure will be described. First, on the surface of the photomask 10 on which the first pattern is formed, a second film made of a material containing a metal different from the metal contained in the materials constituting the first light-shielding film 11 and the semi-permeable film 13 is formed. Light-shielding film 21 (second pattern forming part) (film forming step). For example, the first light-shielding film 11 is made of a Cr-based material, the semi-permeable film 13 is made of MoSi, and the second light-shielding film 21 is made of Ni.

Then, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (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 21 .

Next, a photoresist pattern is formed by drawing on the photoresist film using a drawing device and then developing (pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 in the area corresponding to the additional new light-shielding area will not be removed in the first removal step described below.

Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 21 is removed (first removal step). In the first removal step, only the second light-shielding film 21 is etched and removed using an etching liquid that dissolves the second material but does not dissolve the material constituting the first light-shielding film 11 and the semi-permeable film 13 . Finally, go Remove remaining photoresist film.

Thereby, as shown in Figures 21 and 22, a photomask can be produced that uses the second light-shielding film 21 to add a new light-shielding area while retaining the first light-shielding film 11 and the semi-transmissive film. 13 is the first pattern originally formed on the photomask 10 .

<Modification 5>

In this modification, the pattern correction method described in the first embodiment will be described in which the correction of adding a light-shielding area and the correction of reducing the light-shielding area originally formed on the photomask are performed. FIG. 23 is an enlarged view of one pattern formation area A in the photomask 10 that is the subject of pattern correction in this modification. Figures 24 and 25 are diagrams for explaining the pattern correction method in this modification. Figures 24 and 25 are sectional views corresponding to line H-H shown in Figure 23.

As shown in FIG. 23 , in the pattern formation area A of the photomask 10 that is the object of correction in this modification, a T-shaped first pattern is formed by the first light-shielding film 11 .

In the pattern correction method in this modification, as shown in FIG. 24, a photomask 10 in which a pattern (first pattern) is formed using the first light-shielding film 11 is prepared on the transparent substrate 2 (step S21). Next, a second light-shielding film made of a material (second material) containing a metal different from the metal contained in the material constituting the first light-shielding film 11 is formed on the surface of the photomask 10 on which the first pattern is formed. 21 (step S22, film forming step). Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S23, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S24, pattern forming step). Specifically, the photoresist pattern is formed so that only the photoresist film 22 remains, and the photoresist film 22 is the same as the light-shielding area formed by the first light-shielding film 11 after pattern correction and the new light-shielding area area that is to be added even after pattern correction. Finally, it also corresponds to the area remaining as the shading area. In this modification, the area that is originally a light-shielding area by the first light-shielding film 11 is removed and is intended to be changed into a light-transmitting area. area of the photoresist film 22. In other words, when the photomask 10 is viewed from above, the photoresist pattern is formed so that at least a part of the photoresist film 22 overlapping the first light-shielding film 11 and the second light-shielding film 21 formed in step S22 is removed.

Next, using the photoresist pattern formed in step S24 as a mask, a part of the second light-shielding film 21 is removed (step S25, first removal step). In step S25, only the second light-shielding film 21 is etched away using an etching liquid that dissolves the second material but does not dissolve the material constituting the first light-shielding film 11.

Next, as shown in FIG. 25 , the photoresist pattern formed in step S24 is used as a mask, and a part of the first light-shielding film 11 is removed (step S26 , second removal step). Finally, the remaining photoresist film 22 is removed (step S27).

Figure 26 is a plan view of the photomask corrected using the above method. In Fig. 26, the first light-shielding film 11 before correction is indicated by a chain line. As shown in FIG. 26, by using the correction described above, a new light-shielding area can be added using the new second light-shielding film 21, and at the same time, the light-shielding area originally formed by the first light-shielding film 11 can be reduced when the photomask is viewed from above.

In addition, the pattern correction method in this modification is also applicable to the case where the first pattern is composed of a phase shift film.

<Modification 6>

It will be explained with reference to Figures 27 and 28 that in this modification, the top-type photomask explained in Modification 1 is corrected by adding a light-shielding area, and at the same time, the original formed on the photomask is reduced. Pattern correction method for the correction of the first pattern. Figures 27 and 28 are diagrams for explaining the pattern correction method in this modification.

In the pattern correction method in this modification, as shown in FIG. 27, first, a photomask 10 in which a pattern (first pattern) is formed using the first light-shielding film 11 and the semi-transmissive film 13 is prepared on the transparent substrate 2. (Step S31). Next, on the surface of the photomask 10 on which the first pattern is formed, a film is formed of a material containing a metal different from the metal contained in the materials constituting the first light-shielding film 11 and the semi-permeable film 13 (second material). constitute of the second light-shielding film 21 (step S32, film forming step). Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S33, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S34, pattern forming step). Specifically, the photoresist pattern is formed so that only the area corresponding to the new light-shielding area to be added remains, and the light-shielding area formed by the first light-shielding film 11 after the pattern correction remains as the light-shielding area even after the pattern correction. and the photoresist film 22 in the area of the semi-transmissive area formed by the semi-transmissive film 13 that is to be changed into a light-shielding area. In this modification, the photoresist film 22 is removed from the area that is intended to be changed into a light-transmitting area from the area that is originally a light-shielding area or a semi-transmitting area by the first light-shielding film 11 or the semi-transmissive film 13 . In other words, when the photomask 10 is viewed from above, the photoresist pattern is formed so that at least the photoresist film 22 overlapping the first light-shielding film 11 , the semi-transmissive film 13 and the second light-shielding film 21 formed in step S32 is removed. a part of.

Next, using the photoresist pattern formed in step S34 as a mask, a part of the second light-shielding film 21 is removed (step S35, first removal step). In step S35, an etching liquid that dissolves the second material but does not dissolve the materials constituting the first light-shielding film 11 and the semi-permeable film 13 is used. Thereby, only the second light-shielding film 21 is etched and removed.

Next, as shown in FIG. 28, the photoresist pattern formed in step S34 is used as a mask, and a part of the semi-transmissive film 13 and a part of the first light-shielding film 11 are removed (step S36, second removal step, third removal step). steps). Finally, the remaining photoresist film 22 is removed (step S37). In this embodiment, a part of the semipermeable film 13 and a part of the first light-shielding film 11 are removed in one step. However, in an aspect of the present invention, part of the semipermeable film 13 may be removed separately. step (the second removal step) and the step of removing the first light-shielding film 11 (the third removal step).

According to the above method, a new light-shielding area can be added using the new second light-shielding film 21, and the light-shielding area originally formed by the first light-shielding film 11 when the photomask is viewed from above can be reduced. A part of the semi-transmissive area formed by the semi-transmissive film 13 is changed into a light-shielding area. However, in this modification, the semi-transmissive effect of the photomask 10 before correction is lost.

<Modification 7>

In this modification, referring to Figures 29 and 30, the bottom-type photomask explained in Modification 3 is corrected by adding a light-shielding area, and at the same time, the third area originally formed on the photomask is reduced. 1 Pattern correction method will be explained.

In the pattern correction method in this modification, as shown in FIG. 29 , first, a pattern (first pattern) is formed on the transparent substrate 2 using the first light-shielding film 11 , the semi-permeable film 13 and the etching stop film 14 . photomask 10 (step S41). Next, on the surface of the photomask 10 on which the first pattern is formed, a film is formed of a material containing a metal different from the metal contained in the materials constituting the first light-shielding film 11 and the semi-permeable film 13 (second material). The second light-shielding film 21 is formed (step S42, film forming step). Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S43, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S44, pattern forming step). Specifically, the photoresist pattern is formed so that only the area where a new light-shielding area is to be added is left, and the light-shielding area formed by the first light-shielding film 11 after the pattern correction remains as the light-shielding area even after the pattern correction. The semi-transmissive film 13 becomes a photoresist film 22 corresponding to the area in the semi-transmissive area that is to be changed to a light-shielding area. In this modification, the photoresist film 22 is removed from the area that is intended to be changed into a light-transmitting area from the area that is originally a light-shielding area or a semi-transmitting area by the first light-shielding film 11 or the semi-transmissive film 13 . In other words, when the photomask 10 is viewed from above, the photoresist pattern is formed so that at least the photoresist film 22 overlapping the first light-shielding film 11 , the semi-transmissive film 13 and the second light-shielding film 21 formed in step S42 is removed. a part of.

Next, using the photoresist pattern formed in step S44 as a mask, a part of the second light-shielding film 21 is removed (step S45, first removal step). In step S45, the second material is dissolved using An etching liquid that does not dissolve the materials constituting the first light-shielding film 11 and the semi-permeable film 13 . Thereby, only the second light-shielding film 21 is etched away.

Next, as shown in FIG. 30 , the photoresist pattern formed in step S44 is used as a mask, and a part of the first light-shielding film 11 is removed (step S46 , second removal step). Next, using the photoresist pattern formed in step S44 as a mask, a part of the etching stopper film 14 is removed (step S47, third removal step). Next, using the photoresist pattern formed in step S44 as a mask, a part of the semi-transmissive film 13 is removed (step S48, fourth removal step). Finally, the remaining photoresist film 22 is removed (step S49).

According to the above method, a new light-shielding area can be added using the new second light-shielding film 21, and the light-shielding area originally formed by the first light-shielding film 11 when the photomask is viewed from above can be reduced. In addition, the light-shielding area formed by the semi-transmissive film 13 can be reduced. Part of the semi-transmissive area is changed to a light-blocking area. However, in this modification, the semi-transmissive effect of the photomask 10 before correction is lost.

<Modification 8>

In this modification, referring to Figures 31 and 32, the bottom-type photomask explained in Modification 4 is corrected by adding a light-shielding area, and at the same time, the third area originally formed on the photomask is reduced. 1 Pattern correction method will be explained.

In the pattern correction method in this modification, as shown in FIG. 31, a photomask 10 is prepared on the transparent substrate 2 to form a pattern (first pattern) using the first light-shielding film 11 and the semi-transmissive film 13 (step S51). Next, a second film made of a material containing a metal different from the metal contained in the materials constituting the first light-shielding film 11 and the semi-permeable film 13 is formed on the surface of the photomask 10 on which the first pattern is formed. Light-shielding film 21 (second pattern forming part) (step S52, film forming step). For example, the first light-shielding film 11 may be made of a Cr-based material, the semi-permeable film 13 may be made of MoSi, and the second light-shielding film 21 may be made of Ni. Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S53, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S54, pattern forming step). Specifically, the photoresist pattern is formed so that only the area where a new light-shielding area is to be added is left, and the light-shielding area formed by the first light-shielding film 11 after the pattern correction remains as the light-shielding area even after the pattern correction. The semi-transmissive film 13 becomes a photoresist film 22 corresponding to the area in the semi-transmissive area that is to be changed to a light-shielding area. In this modification, the photoresist film 22 is removed from the area that is intended to be changed into a light-transmitting area from the area that is originally a light-shielding area or a semi-transmitting area by the first light-shielding film 11 or the semi-transmissive film 13 . In other words, when the photomask 10 is viewed from above, the photoresist pattern is formed so that at least the photoresist film 22 overlapping the first light-shielding film 11 , the semi-transmissive film 13 and the second light-shielding film 21 formed in step S52 is removed. a part of.

Next, using the photoresist pattern formed in step S54 as a mask, a part of the second light-shielding film 21 is removed (step S55, first removal step). In step S55, only the second light-shielding film 21 is etched away using an etching liquid that dissolves the second material but does not dissolve the material constituting the first light-shielding film 11 and the semi-permeable film 13.

Next, as shown in FIG. 32, the photoresist pattern formed in step S54 is used as a mask, and a part of the first light-shielding film 11 is removed (step S56, second removal step). Next, using the photoresist pattern formed in step S54 as a mask, a part of the semi-transmissive film 13 is removed (step S57, third removal step). Finally, the remaining photoresist film 22 is removed (step S58).

According to the above method, a new light-shielding area can be added using the new second light-shielding film 21. When the photomask is viewed from above, the light-shielding area originally formed by the first light-shielding film 11 can be reduced. In addition, the light-shielding area formed by the semi-transmissive film 13 can be reduced. Part of the semi-transmissive area is changed to a light-blocking area. However, in this modification, the semi-transmissive effect of the photomask 10 before correction is lost.

[Second Embodiment]

Another embodiment of the present invention will be described below. For convenience of explanation, components having the same functions as those described in the above embodiments will be labeled with the same symbols and will not be described again.

In the first embodiment, a pattern correction method has been described in which a light-shielding portion formed of the second light-shielding film 21 is newly formed on a photomask in which a pattern has been previously formed with the first light-shielding film 11 . In contrast, the pattern correction method of this embodiment is a method of forming a transmission part on a light-shielding film and re-forming a transmission part on a photomask on which a pattern is formed.

FIG. 33 is a plan view showing the structure of a photomask 30 as an example of a photomask to be corrected by the pattern correction method in this embodiment. Fig. 34 is an enlarged view showing the area D4 shown in Fig. 33, and is an enlarged view of one pattern forming area A.

As shown in FIG. 33 , the photomask 30 forms a plurality of pattern forming areas A on the transparent substrate 2 . In the pattern formation area A, as shown in FIG. 34, a light-shielding film 41 is formed on the transparent substrate 2, and a light-transmitting portion 42 is patterned on the light-shielding film 41. In this embodiment, an example in which the circular light-transmitting portion 42 is formed in one pattern formation area A will be described.

Fig. 35 is a diagram showing a portion where the pattern is to be corrected using the pattern correction method in this embodiment. In this embodiment, as shown in FIG. 35 , an example is explained in which the pattern is modified so that the light-transmitting part is re-formed in the area D5 located at the center of the circle formed by the light-transmitting part 42 .

FIG. 36 is a flowchart showing an example of the pattern correction method in this embodiment. Fig. 37 is a diagram for explaining the pattern correction method in this embodiment. As shown in Figures 36 and 37, in the pattern correction method in this embodiment, first, a photomask 30 in which a pattern has been formed by patterning the light-shielding film 41 using the light-transmitting portion 42 is prepared (step S61 ).

Next, the photoresist film 51 is formed on the patterned surface of the photomask 30 (step S62). Next, a drawing device is used to draw on the photoresist film 51, and then development is performed to form a photoresist pattern (step S63). Specifically, the photoresist pattern is formed so that the light-shielding film 41 corresponding to the area D5 shown in FIG. 35 is removed in step S14 described below.

In step S63 in this embodiment, the photomask 30 is positioned based on the calibration mark 4 preliminarily formed on the transparent substrate 2 of the photomask 30 and then is drawn using a drawing device. thus, The additional position of the newly added transmitting part can be controlled with high precision. In addition, when there is no need to increase the accuracy of the formation position of the transparent portion, there is no need to use the alignment mark 4 to position the photomask 30 .

Next, the photoresist pattern formed in step S63 is used as a mask, and a part of the light-shielding film 41 is removed (step S64). As a result, the light-transmitting portion 45 can be newly formed.

Finally, the remaining photoresist film 51 is removed (step S65). As a result, a photomask in which a new light-transmitting portion 45 is formed in addition to the previously formed light-transmitting portion 42 can be manufactured.

In each of the above embodiments, the pattern correction using a positive photoresist film has been described, but the present invention is not limited thereto. In one aspect of the present invention, a negative photoresist film can be used for pattern correction.

[Third Embodiment]

Another embodiment of the present invention will be described below. In this embodiment, an example of a pattern correction method for re-correcting the pattern using a photomask (photomask 10 shown in FIG. 1) on which a light-shielding film has been formed on a transparent substrate will be described.

In this embodiment, as shown in FIG. 3 , the area D2 adjacent to the inside of the circle formed by the first light-shielding film 11 and the area located in the center of the circle and not adjacent to the first light-shielding film 11 are considered. An example in which the pattern of the light shielding portion is newly formed on D3 and corrected will be described. In this embodiment, one pattern forming area A is explained, but for other pattern forming areas A, each pattern will be corrected as necessary.

FIG. 38 is a flowchart showing an example of the pattern correction method in this embodiment. Figure 39 is a diagram for explaining the pattern correction method in this embodiment. Each figure shown in FIG. 39 is a cross-sectional view cut on a surface perpendicular to the surface of the transparent substrate 2 through the center of the circle formed by the first light-shielding film 11 . As shown in Figures 38 and 39, in the pattern correction method in this embodiment, first, a photomask 10 with a first pattern formed on the transparent substrate 2 using the first light-shielding film 11 is prepared (step S101).

Next, on the surface of the photomask 10 on which the first pattern is formed, etching films are sequentially formed. The etching stopper film 20 and the second light-shielding film 21 (second pattern forming part) containing a second material of the same metal as the first material (step S102, film forming step). The etching stopper film 20 and the second light-shielding film 21 are formed by, for example, sputtering, evaporation, or the like. The first material is a material composed of a first metallic element (for example, Cr, Ni, etc.) and a first non-metal element, and the second material is composed of the first metallic element and a second non-metal element different from the first non-metal element. Material composed of metallic elements. The etching stopper film 20 is made of a material that is not etched by the solvent used to etch the second light-shielding film 21 . As the etching stop film 20, for example, titanium, nickel, molybdenum silicide (molybdenum silicide), etc. can be used.

Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S103, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 . The photoresist film 22 is formed by, for example, a coating method, a spray coating method, or the like.

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S104, pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 corresponding to the area D2 and the area D3 shown in FIG. 3 will not be removed in the first removal step described below. Development can be performed by a stirring method, a dipping method, a spraying method, a rotating method, etc.

In step S104 in this embodiment, the photomask 10 is positioned based on the calibration mark 4 formed at the same time when the first pattern is formed by the first light-shielding film 11 on the transparent substrate 2 of the photomask 10 . , draw with a drawing device. In other words, using the calibration mark 4 as a reference, the drawing device is used to draw on the photoresist film 22 . Thereby, the position where a newly added pattern is added can be controlled with high precision. In addition, when there is no need to increase the accuracy of the pattern formation position, there is no need to use the alignment mark 4 to position the photomask 10 .

Next, using the photoresist pattern formed in step S104 as a mask, a part of the second light-shielding film 21 is removed (step S105, first removal step). Thereby, in the second light-shielding film 21 formed in step S102, the second light-shielding film 21 other than the second light-shielding film 21 corresponding to the region D2 and the region D3 shown in FIG. 3 is removed. Light-shielding film 21. In step S104, a solvent that does not dissolve the etching stop film 20 is used as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is etched away.

Next, the remaining photoresist film 22 is removed (step S106). The photoresist film 22 can be removed by, for example, stirring, ashing, or immersing in a photoresist stripping solution. Finally, the etching stopper film 20 is removed using the second light-shielding film 21 that has not been removed in step S105 as a mask (step S107, etching stopper film removal step). Thereby, a photomask in which a new light-shielding portion is added using the second light-shielding film 21 while retaining the first light-shielding film originally formed on the photomask 10 is produced.

Similar to the first embodiment 1, in this embodiment, as shown in FIG. 6 , in the pattern formation area A after pattern correction, the second light-shielding film 21 is formed in the area D2 and the area D3 shown in FIG. 3 . By forming the second light-shielding film 21 in the region D2, the area of the light-shielding region formed by the first light-shielding film 11 before pattern correction can be enlarged. In other words, when the photomask 10 is viewed from above, the width of the light-shielding region formed by the first light-shielding film 11 can be enlarged. In addition, by forming the second light-shielding film 21 on the area D3, additional light-shielding areas can be formed.

As described above, in the pattern correction method of this embodiment, the etching stopper film 20 and the second light-shielding film composed of the first material constituting the first light-shielding film 11 are formed on the entire surface of the existing photomask 10 film 21, and patterning the second light-shielding film 21 using yellow photolithography. With this structure, the second light-shielding film 21 can be additionally patterned on the entire surface of the photomask 10 . That is, the pattern correction method in this embodiment can perform large-scale pattern correction at one time. As a result, the pattern of the patterned photomask can be corrected in a short time.

In addition, in the pattern correction method in this embodiment, a light-shielding area is additionally formed on the second light-shielding film 21 made of the same metal material as the first material constituting the first light-shielding film 11 . Thereby, when cleaning the photomask 10 after correction, the same cleaning solution as that of the photomask 10 before correction can be used. The materials constituting the first light-shielding film 11 and the second light-shielding film 21 (that is, the first material and the second material) can be selected from conventional materials such as Cr-based metal compounds, Si-based compounds, and metal silicide compounds. Select in. For example, the material constituting the first light-shielding film 11 and the second light-shielding film 21 may contain metal Cr, Cr oxide, Cr nitride, Cr carbide, Cr oxynitride, Cr nitride carbide, Cr oxycarbide, Any one or more Cr-based metal compounds among Cr oxynitrides.

In addition, with the pattern correction method in this embodiment, the film peeling phenomenon that occurs when CVD is used as in the technology of Japanese Patent Document 1 does not occur. In addition, when using CVD such as the technology of Japanese Patent Document 1, the laser irradiates areas other than the desired area and forms light-shielding portions outside the desired area. Therefore, it is necessary to remove the light-shielding portion while shaping. . In contrast, in the pattern correction method of this embodiment, since a drawing device is used to form the pattern of the second light-shielding film 21, the pattern can be added with high accuracy and unnecessary light-shielding portions do not need to be removed.

The photomask corrected by the pattern correction method in this embodiment is to add a new pattern to the photomask in which the first pattern has been formed on the transparent substrate 2 using the first light-shielding film 11, which has: (1) the first pattern; (2) a pattern formed adjacent to the first pattern on the transparent substrate 2 when the photomask is viewed from above, in which the pattern of the light-shielding area formed by the etching stopper film 20 and the second light-shielding film 21 ( second pattern); and (3) a pattern formed not adjacent to the first pattern when the photomask is viewed from above, wherein a pattern (second pattern) is formed by the etching stopper film 20 and the second light-shielding film 21 .

<Modification 9>

In the third embodiment, the pattern correction method of newly forming the light-shielding portion formed of the second light-shielding film 21 on the photomask on which the first pattern has been formed in advance using the first light-shielding film 11 has been described. However, the present invention does not Not limited to this. In one aspect of the present invention, a photomask in which the first pattern is formed of a film other than a light-shielding film can be used. Detailed description is provided with reference to Figure 7, Figure 8, Figure 40 and Figure 41.

The photomask 10 to be corrected in this modification is a top-type photomask shown in FIGS. 7 and 8 . Fig. 40 is a diagram showing the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. Fig. 41 is a cross-sectional view along line B-B shown in Fig. 40.

The pattern correction method of the photomask 10 of this modification will be described. First of all, in shape On the surface of the photomask 10 on which the first pattern is formed, an etching stop film 20 and a second light-shielding film containing a second material of the same metal as the material constituting the semi-permeable film 13 (the first material) are sequentially formed. 21 (Second pattern forming part) (film forming step).

Then, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (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 21 .

Next, a photoresist pattern is formed by drawing on the photoresist film using a drawing device and then developing (pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 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.

Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 21 is removed (first removal step). In the first removal step, a solvent that does not dissolve the etching stop film 20 is used as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is etched and removed.

Then, remove the remaining photoresist film. Finally, in the first removal step, the etching stopper film 20 is removed using the second light-shielding film 21 that has not been removed as a mask (the etching stopper film removal step). Thereby, as shown in Figures 40 and 41, a photomask can be produced that uses the second light-shielding film 21 to add a new light-shielding area while retaining the original light-shielding areas of the first light-shielding film 11 and the semi-transmissive film 13. The first pattern is formed on the photomask 10 .

Fig. 42 is a diagram showing another example of the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. As shown in FIG. 42, in one aspect of the present invention, when the photomask 10 is viewed from above, a part of the second light-shielding film 21 and a part of the first pattern (more specifically, the first pattern is formed with a The second light-shielding film 21 is formed in an overlapping manner (part of the area of the light-shielding film 11). Thereby, the shape of the light-shielding area of the photomask 10 can be changed.

FIG. 43 is a diagram showing another example of the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. As shown in Figure 43, in one aspect of the present invention, when viewed from above, When using the mask 10 , the second light-shielding film 21 may be formed to include the entire area of the first pattern formed by the first light-shielding film 11 and the semi-transmissive film 13 . Thereby, the area of the light-shielding area of the photomask 10 can be enlarged. However, in this case, the semi-transmissive effect of the photomask 10 before correction will disappear.

In this modification, the method of performing pattern correction on a photomask in which a pattern (first pattern) is formed by the first light-shielding film 11 and the semi-transmissive film 13 as the first pattern forming portion has been described. However, in the present invention, In one aspect, pattern correction can be performed in the same manner on a photomask using a phase shift film instead of the first light-shielding film 11 .

<Modification 10>

Each of the above pattern correction methods can also be performed on a photomask in which the first pattern is formed of a phase shift film. The transmittance of the phase shift film is about 1 to 15%, and it is a semi-permeable film that has the effect of reversing (or shifting) the phase. The phase shift effect is used to improve the resolution. However, as shown in the example of FIG. 43, when the photomask 10 is viewed from above, when the second light-shielding film 21 is formed so as to include the entire area of the first pattern formed by the phase shift film, the photomask before correction is The phase shifting effect of membrane 10 will disappear.

When correcting the photomask 10 in which the first pattern is formed of a phase shift film, the phase shift film may be used instead of the second light-shielding film 21 for correction. Thereby, the shape of the area having a phase shift effect can be changed. However, as shown in the example of FIG. 43 , when the photomask 10 is viewed from above, when the phase shift film is formed so as to include the entire area of the first pattern formed by the phase shift film, when the photomask 10 is viewed from above, Then the phase shift effect will disappear in the area where the phase shift film overlaps, and it will become a photomask that can only obtain the phase shift effect in the area where the newly formed phase shift film exists (that is, an edge-enhanced photomask) .

<Modification 11>

In Modification 9, the method of correcting the pattern of the top-type halftone 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 halftone mask. For detailed instructions, please refer to Figures 44 to 45.

The photomask 10 used as the pattern correction target in this modification is shown in Figures 13 and 14 Bottom type halftone mask shown. Fig. 44 is a diagram showing the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. Fig. 45 is a cross-sectional view along line E-E shown in Fig. 44.

The pattern correction method of the photomask 10 of this modification will be described. First, on the surface of the photomask 10 on which the first pattern is formed, the etching stop film 20 and the same metal as the material (first material) constituting the first light-shielding film 11 and the semi-permeable film 13 are sequentially formed. The second light-shielding film 21 (second pattern forming part) of the second material (film forming step).

Then, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (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 21 .

Next, a photoresist pattern is formed by drawing on the photoresist film using a drawing device and then developing (pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 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.

Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 21 is removed (first removal step). In the first removal step, a solvent that does not dissolve the etching stop film 20 is used as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is etched and removed.

Then, remove the remaining photoresist film. Finally, in the first removal step, the etching stopper film 20 is removed using the second light-shielding film 21 that has not been removed as a mask (the etching stopper film removal step). Thereby, as shown in Figures 44 and 45, a photomask can be produced that uses the second light-shielding film 21 to add a new light-shielding area while retaining the original light-shielding areas of the first light-shielding film 11 and the semi-transmissive film 13. The first pattern is formed on the photomask 10 .

In this modification, the method of performing pattern correction on a photomask in which a pattern (first pattern) is formed by the first light-shielding film 11 and the semi-transmissive film 13 as the first pattern forming portion has been described. However, in the present invention, In one aspect, pattern correction can be performed in the same manner on a photomask using a phase shift film instead of the first light-shielding film 11 .

In addition, in one aspect of the present invention, when pattern correction is performed on a photomask using a phase shift film instead of the first light-shielding film 11, a semi-transmissive film that partially transmits exposure light may be used instead of the second light-shielding film 21. . In this case, the transmittance of the phase shift film is preferably 3~15%. In addition, in one aspect of the present invention, in a photomask using a semi-transmissive film instead of the first light-shielding film 1, a phase shift film can be used instead of the second light-shielding film 21 to perform pattern correction. In this case, the semi-permeable film preferably has a transmittance of 10 to 70% and a phase shift angle of 0.1° to 20° relative to the exposure light.

Next, with reference to Figures 46 and 47, a new light-shielding area is added to the bottom-type halftone photomask 10 shown in Figures 13 and 14, and at the same time, the first light-shielding film 11 is A pattern correction method in which a part of the light-blocking area is changed into a semi-transmissive area and is corrected will be described. Figures 46 and 47 are diagrams for explaining this pattern correction method. Each of the figures shown in Fig. 46 and Fig. 47 is a cross-sectional view along line D-D shown in Fig. 13.

In this pattern correction method, as shown in FIG. 46, a photomask 10 (first pattern) formed with a first light-shielding film 11, a semi-transmissive film 13, and an etching stopper film 14 is prepared on the transparent substrate 2. Step S111). Next, on the surface of the photomask 10 on which the first pattern is formed, an etching stop film 20 and a second light-shielding film 21 (second pattern forming part) containing the first material are sequentially formed (step S112, forming membrane step). Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S113, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is performed to form a photoresist pattern (step S114, pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 corresponding to the area to be changed to the light-shielding area is not removed in the first removal step described below.

Next, using the photoresist pattern formed in step S114 as a mask, a part of the second light-shielding film 21 is removed (step S115, first removal step). In step S115, use the insoluble etching stop The solvent of the stopper film 20 serves as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is etched away.

Next, as shown in FIG. 47, the photoresist pattern formed in step S114 is used as a mask, and a part of the etching stop film 20 is removed (step S116). Next, using the photoresist pattern formed in step S114 as a mask, a part of the first light-shielding film 11 is removed (step S117). Then, using the photoresist pattern formed in step S114 as a mask, a part of the etching stopper film 14 is removed (step S118). Finally, the remaining photoresist film 22 is removed (step S19).

According to the above method, a new light-shielding area is added using the new second light-shielding film 21. At the same time, when the photomask is viewed from above, the semi-transmissive film 13 can be used to expose a portion of the first light-shielding film 11 that originally became the light-shielding area. Part of the light-blocking area is changed to a semi-transparent area.

<Modification 12>

In Modification 11, the modified semipermeable film 13 and the first light-shielding film 11 made of the same metal material and the etching stopper film 14 arranged between the semipermeable film 13 and the first light-shielding film 11 are described. A bottom-type half-tone mask pattern method is used, but the present invention is not limited thereto. The pattern correction method according to one aspect of the present invention can also be applied to bottom-type halftone masks having other structures. For detailed description, please refer to Figure 19, Figure 20, Figure 48 and Figure 49.

The photomask 10 used as the pattern correction target in this modification is a bottom-type halftone mask shown in FIGS. 19 and 20 . Fig. 48 is a diagram showing the pattern formation area A after the pattern has been corrected using the pattern correction method of this modification. Fig. 49 is a cross-sectional view along line G-G shown in Fig. 48.

The pattern correction method of the photomask 10 of this modification will be described. First, an etching stopper film 20 and a second light-shielding film 21 (second pattern forming portion) are sequentially formed on the surface of the photomask 10 on which the first pattern is formed (film formation step).

Then, a photoresist film is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (photoresist film forming step). In other words, a photoresist film is formed on the surface of the photomask 10 to cover the 2 The entire surface of the light-shielding film 21.

Next, a photoresist pattern is formed by drawing on the photoresist film using a drawing device and then developing (pattern forming step). Specifically, the photoresist pattern is formed so that only the second light-shielding film 21 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.

Next, using the formed photoresist pattern as a mask, a part of the second light-shielding film 21 is removed (first removal step). In the first removal step, a solvent that does not dissolve the etching stop film 20 is used as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is etched and removed.

Then, remove the remaining photoresist film. Finally, in the first removal step, the etching stopper film 20 is removed using the second light-shielding film 21 that has not been removed as a mask (the etching stopper film removal step). Thereby, as shown in Figures 48 and 49, a photomask can be produced that uses the second light-shielding film 21 to add a new light-shielding area while retaining the original light-shielding areas of the first light-shielding film 11 and the semi-transmissive film 13. The first pattern is formed on the photomask 10 .

<Modification 13>

In this modification, the pattern correction method described in the third embodiment will be described in which the correction of adding a light-shielding area and the correction of reducing the light-shielding area originally formed on the photomask are performed. Figures 50 and 51 are diagrams for explaining the pattern correction method in this modification. Each of the figures shown in Fig. 50 and Fig. 51 corresponds to the H-H line cross-sectional view shown in Fig. 23. The photomask 10 to be corrected in this modification is a photomask 10 in which a T-shaped first pattern is formed with the first light-shielding film 11 in the pattern formation area A shown in FIG. 23 .

In the pattern correction method in this modification, as shown in FIG. 50 , a photomask 10 in which a pattern (first pattern) is formed using the first light-shielding film 11 is prepared on the transparent substrate 2 (step S121 ). Next, on the surface of the photomask 10 on which the first pattern is formed, an etching stop film 20 and a second light-shielding film 21 (second pattern forming part) containing the first material are sequentially formed (step S122, forming membrane step). Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S123, photoresist film formation steps). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S124, pattern forming step). Specifically, the photoresist pattern is formed so that only the photoresist film 22 remains, and the photoresist film 22 is the same as the light-shielding area formed by the first light-shielding film 11 after pattern correction and the new light-shielding area area that is to be added even after pattern correction. Finally, it also corresponds to the area remaining as the shading area. In this modification, the photoresist film 22 is removed from the area that is to be changed into a light-transmitting area from the area that is originally a light-shielding area by the first light-shielding film 11 . In other words, when the photomask 10 is viewed from above, the photoresist pattern is formed so that at least the photoresist film 22 overlapping the first light-shielding film 11 and the etching stop film 20 and the second light-shielding film 21 formed in step S122 is removed. a part of.

Next, using the photoresist pattern formed in step S124 as a mask, a part of the second light-shielding film 21 is removed (step S125, first removal step). In step S125, a solvent that does not dissolve the etching stop film 20 is used as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is removed by etching.

Next, as shown in FIG. 51, the photoresist pattern formed in step S124 is used as a mask, and a part of the etching stop film 20 is removed (step S126). Next, using the photoresist pattern formed in step S124 as a mask, a part of the first light-shielding film 11 is removed (step S127, second removal step). Finally, the remaining photoresist film 22 is removed (step S27).

Fig. 52 is a plan view showing the photomask corrected by the above method. In Fig. 52, the first light-shielding film 11 before correction is shown by a chain line. As shown in FIG. 52, according to the modification of the above method, a new light-shielding area can be added using the second light-shielding film 21, and at the same time, the light-shielding area originally formed by the first light-shielding film 11 can be reduced when the photomask is viewed from above.

In addition, the pattern correction method in this modification is also applicable to the case where the first pattern is composed of a phase shift film.

<Modification 14>

It will be explained with reference to Figures 53 and 54 that in this modification, the top-type photomask explained in Modification 9 is corrected by adding a light-shielding area, and at the same time, the original formed on the photomask is reduced. Pattern correction method for the correction of the first pattern. Figures 53 and 54 are diagrams for explaining the pattern correction method in this modification.

In the pattern correction method in this modification, as shown in FIG. 53 , first, a photomask 10 in which a pattern (first pattern) is formed using the first light-shielding film 11 and the semi-transmissive film 13 is prepared on the transparent substrate 2 (Step S131). Next, on the surface of the photomask 10 on which the first pattern is formed, the etching stop film 20 and the second light-shielding film 21 containing the first material are sequentially formed (step S132, film forming step). Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S133, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S134, pattern forming step). Specifically, the photoresist pattern is formed so that only the area where a new light-shielding area is to be added is left, and the light-shielding area formed by the first light-shielding film 11 after the pattern correction remains as the light-shielding area even after the pattern correction. The semi-transmissive film 13 becomes a photoresist film 22 corresponding to the area in the semi-transmissive area that is to be changed to a light-shielding area. In this modification, the photoresist film 22 is removed from the area that is intended to be changed into a light-transmitting area from the area that is originally a light-shielding area or a semi-transmitting area by the first light-shielding film 11 or the semi-transmissive film 13 . In other words, when the photomask 10 is viewed from above, the photoresist pattern is formed so as to remove at least the first light-shielding film 11 , the semi-transmissive film 13 , the etching stop film 20 and the second light-shielding film 21 formed in step S132 . part of the photoresist film 22 .

Next, using the photoresist pattern formed in step S134 as a mask, a part of the second light-shielding film 21 is removed (step S135, first removal step). In step S135, a solvent that does not dissolve the etching stop film 20 is used as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is removed by etching.

Next, as shown in Figure 54, the photoresist pattern formed in step S134 is used as a mask. The mold is formed, and a part of the etching stop film 20 is removed (step S136). Next, using the photoresist pattern formed in step S134 as a mask, a part of the semi-transmissive film 13 is removed (step S137, second removal step). Then, using the photoresist pattern formed in step S134 as a mask, a part of the first light-shielding film 11 is removed (step S138, third removal step). Finally, the remaining photoresist film 22 is removed (step S139).

According to the above method, a new light-shielding area can be added using the new second light-shielding film 21, and the light-shielding area originally formed by the first light-shielding film 11 when the photomask is viewed from above can be reduced. In addition, the light-shielding area formed by the semi-transmissive film 13 can be reduced. Part of the semi-transmissive area is changed to a light-blocking area. However, in this modification, the semi-transmissive effect of the photomask 10 before correction is lost.

<Modification 15>

It will be explained with reference to Figures 55 and 56 that in this modification, the top-type photomask explained in Modification 11 is corrected by adding a light-shielding area, and at the same time, the original formed on the photomask is reduced. Pattern correction method for the correction of the first pattern. Figures 55 and 56 are diagrams for explaining the pattern correction method in this modification.

In the pattern correction method in this modification, as shown in FIG. 55, first, the first light-shielding film 11, the semi-permeable film 13 and the etching stop film 14 are prepared on the transparent substrate 2 to form a pattern (first pattern) photomask 10 (step S141). Next, on the surface of the photomask 10 on which the first pattern is formed, an etching stop film 20 and a second light-shielding film 21 (second pattern forming portion) containing the first material are sequentially formed. Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S143, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is performed to form a photoresist pattern (step S144, pattern forming step). Specifically, the photoresist pattern is formed so that only the area where a new light-shielding area is to be added is left, and the light-shielding area formed by the first light-shielding film 11 after the pattern correction remains as the light-shielding area even after the pattern correction. area, and the semipermeable membrane 13 becomes semipermeable The photoresist film 22 corresponding to the area where the area is to be changed to the light-shielding area is passed. In this modification, the photoresist film 22 is removed from the area that is intended to be changed into a light-transmitting area from the area that is originally a light-shielding area or a semi-transmitting area by the first light-shielding film 11 or the semi-transmissive film 13 . In other words, when the photomask 10 is viewed from above, the photoresist pattern is formed so as to remove at least the first light-shielding film 11 , the semi-transmissive film 13 , the etching stop film 20 and the second light-shielding film 21 formed in step S142 . part of the photoresist film 22 .

Next, using the photoresist pattern formed in step S144 as a mask, a part of the second light-shielding film 21 is removed (step S145, first removal step). In step S145, a solvent that does not dissolve the etching stop film 20 is used as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is removed by etching.

Next, as shown in FIG. 56, the photoresist pattern formed in step S144 is used as a mask, and a part of the etching stopper film 20 is removed (step S146, etching stopper film removal step). Next, using the photoresist pattern formed in step S144 as a mask, a part of the first light-shielding film 11 is removed (step S147, second removal step). Next, using the photoresist pattern formed in step S144 as a mask, a part of the etching stop film 14 is removed (step S148, third removal step). Next, using the photoresist pattern formed in step S144 as a mask, a part of the semi-transmissive film 13 is removed (step S149, fourth removal step). Finally, the remaining photoresist film 22 is removed (step S150).

According to the above method, a new light-shielding area can be added using the new second light-shielding film 21, and the light-shielding area originally formed by the first light-shielding film 11 when the photomask is viewed from above can be reduced. In addition, the light-shielding area formed by the semi-transmissive film 13 can be reduced. Part of the semi-transmissive area is changed to a light-blocking area. However, in this modification, the semi-transmissive effect of the photomask 10 before correction is lost.

<Modification 16>

It will be explained with reference to Figures 57 and 58 that in this modified example, the bottom-type photomask explained in Modified Example 12 is corrected by adding a light-shielding area, and at the same time, the original formed on the photomask is reduced. Pattern correction method for the correction of the first pattern. Figures 57 and 58 are used to illustrate this modification. Diagram of pattern correction method.

In the pattern correction method in this modification, as shown in FIG. 57 , a photomask 10 in which a pattern (first pattern) is formed using the first light-shielding film 11 and the semi-transmissive film 13 is prepared on the transparent substrate 2 (step S151). Next, on the surface of the photomask 10 on which the first pattern is formed, an etching stop film 20 and a second light-shielding film 21 (second pattern forming portion) containing the first material are sequentially formed. Then, the photoresist film 22 is formed on the entire surface of the photomask 10 including the second light-shielding film 21 (step S153, photoresist film forming step). In other words, the photoresist film 22 is formed on the surface of the photomask 10 so as to cover the entire surface of the second light-shielding film 21 .

Next, a drawing device is used to draw on the photoresist film 22, and then development is used to form a photoresist pattern (step S154, pattern forming step). Specifically, the photoresist pattern is formed so that only the area where a new light-shielding area is to be added is left, and the light-shielding area formed by the first light-shielding film 11 after the pattern correction remains as the light-shielding area even after the pattern correction. area, and the photoresist film 22 corresponding to the area in the semi-transmissive area that is to be changed to a light-shielding area from the semi-transmissive film 13 . In this modification, the photoresist film 22 is removed from the area that is intended to be changed into a light-transmitting area from the area that is originally a light-shielding area or a semi-transmitting area by the first light-shielding film 11 or the semi-transmissive film 13 . In other words, when the photomask 10 is viewed from above, the photoresist pattern is formed so as to remove at least the first light-shielding film 11 , the semi-transmissive film 13 , the etching stop film 20 and the second light-shielding film 21 formed in step S152 . part of the photoresist film 22 .

Next, using the photoresist pattern formed in step S154 as a mask, a part of the second light-shielding film 21 is removed (step S155, first removal step). In step S155, a solvent that does not dissolve the etching stop film 20 is used as a solvent for etching the second light-shielding film 21, and only the second light-shielding film 21 is removed by etching.

Next, as shown in FIG. 58 , the photoresist pattern formed in step S154 is used as a mask, and a part of the etching stopper film 20 is removed (step S156 , etching stopper film removal step). Next, using the photoresist pattern formed in step S154 as a mask, a part of the first light-shielding film 11 is removed (step S157, second removal step). Next, use the photoresist pattern formed in step S154 as a mask, and A part of the etching stop film 13 is removed (step S158, third removal step). Finally, the remaining photoresist film 22 is removed (step S159).

According to the above method, a new light-shielding area can be added using the new second light-shielding film 21, and the light-shielding area originally formed by the first light-shielding film 11 when the photomask is viewed from above can be reduced. In addition, the light-shielding area formed by the semi-transmissive film 13 can be reduced. Part of the semi-transmissive area is changed to a light-blocking area. However, in this modification, the semi-transmissive effect of the photomask 10 before correction is lost.

The present invention is not limited to the above-described embodiments, and various changes can be made within the scope indicated in the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technology of the present invention. within the range.

2:Transparent substrate

10:Photomask

11: 1st light-shielding film (1st pattern forming part)

21: Second light-shielding film (second pattern forming part)

22: Photoresist film

S1~S6: steps

Claims (27)

A pattern correction method is to correct a new pattern on a photo mask (photo mask) that has been patterned on a transparent substrate using a first pattern forming part containing a first material, which includes the following steps: a film forming step, A second pattern forming part is formed on the surface of the photomask on which the pattern is formed; a photoresist film forming step is to form a photoresist film on the surface of the photomask to cover the second pattern formation the entire surface of the part; a pattern forming step, using a drawing device to draw and form a photoresist pattern on the photoresist film; and a first removal step, using the photoresist pattern as a mask, removing the second pattern forming part A part of the photoresist film, wherein in the pattern forming step, when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least a part of the photoresist film that overlaps with the pattern of the first pattern forming portion. The pattern correction method of claim 1, wherein: in the film forming step, the second pattern forming part is formed on the surface of the photomask on which the pattern is formed, and the second pattern forming part contains the same as the first The second material is made of different materials. In the first removal step, the photoresist pattern is used as a mask and an etching liquid that dissolves the second material but does not dissolve the first material is used to remove a part of the second pattern forming part. . The pattern correction method of claim 2, wherein: the first pattern forming part is a first light shielding film having light shielding properties; the second pattern forming part is a second light shielding film having light shielding properties; in the pattern forming step, When the photomask is viewed from above, the photoresist pattern is formed to remove at least a portion of the photoresist film that overlaps the first light-shielding film; after the first removal step, a second removal step is also included, and the second removal step is The step uses the photoresist pattern as a mask and removes a part of the first light-shielding film. For example, the pattern correction method of request item 2, wherein: The first pattern forming part includes a semi-transmissive film and a first light-shielding film or phase shift film. The first light-shielding film is disposed on a part of the area between the semi-transmissive film and the transparent substrate. has light-shielding properties; the second pattern forming portion is a second light-shielding film with light-shielding properties; in the pattern forming step, when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least the first light-shielding film or The part of the photoresist film where the phase shift film overlaps, after the first removal step, also includes: a second removal step of using the photoresist pattern as a mask and removing a part of the semi-transmissive film; and a third removal step Step: use the photoresist pattern as a mask and remove part of the first light-shielding film or the phase shift film. The pattern correction method of claim 2, wherein: the first pattern forming part includes a phase shift film; the second pattern forming part includes a phase shift film or a second light shielding film with light shielding properties; in the pattern forming step, When the photomask is viewed from above, the photoresist pattern is formed to remove at least a portion of the photoresist film that overlaps the phase shift film; after the first removal step, a second removal step is also included, using the photoresist pattern. as a mask and remove part of the phase shift film. The pattern correction method of claim 2, wherein: the first pattern forming part includes a semi-transmissive film or a phase shift film formed on a transparent substrate; and a first light-shielding film with light-shielding properties, and the first light-shielding film is A part of the surface of the semipermeable film or the phase shift film opposite to the transparent substrate side is laminated with an etching stopper film, and the second pattern forming portion includes a second light-shielding film having light-shielding properties. The pattern correction method of claim 6, wherein: in the pattern forming step, when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least a portion of the photoresist film overlapping the first light-shielding film, After the first removal step, it also includes: a second removal step, using the photoresist pattern as a mask and removing a part of the first light-shielding film; a third removal step, using the photoresist pattern as a mask and removing the Etching a part of the stop film; and a fourth removal step, using the photoresist pattern as a mask and removing a part of the semi-transmissive film or the phase shift film. The pattern correction method of claim 2, wherein: the first pattern forming part includes: a semi-permeable film or a phase shift film, which includes a third material different from the first material and the second material and is formed on the transparent substrate and a first light-shielding film, which is laminated on a part of the surface of the semi-transmissive film or the phase shift film opposite to the transparent substrate side and has light-shielding properties, and the second pattern forming part It is a second light-shielding film having light-shielding properties. In the pattern forming step, when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least a portion of the photoresist film overlapping the first light-shielding film. After the first removal step, it also includes: a second removal step, using the photoresist pattern as a mask and removing a part of the first light-shielding film; and a third removal step, using the photoresist pattern as a mask and removing the half of the first light-shielding film. permeable membrane or part of the phase shift membrane. The pattern correction method of claim 1, wherein: in the film forming step, an etching stop film and a film containing the same metal as the first material are sequentially formed on the surface of the photomask on which the pattern is formed. The second pattern forming portion of the second material further includes an etching stop film removal step. The etching stop film removing step removes the second pattern forming portion or the photoresist pattern that has not been removed in the first removal step. This etch stop film is removed as a mask. For example, the pattern correction method of claim 9, wherein the first material and the second material are Cr-based metal compounds, Si-based compounds or metal silicides (Silicide). The pattern correction method of claim 2, 3, 9 or 10, wherein in the pattern forming step, a calibration mark formed while forming a pattern on the transparent substrate by the first pattern forming part is used as a reference, and the drawing is used The device draws on the photoresist film. The pattern correction method of claim 2, 3, 9 or 10, wherein the photoresist pattern is formed in the pattern forming step so that when the photomask is viewed from above, the first portion that has not been removed in the first removal step A part of the 2 pattern forming portion is adjacent to the first pattern forming portion. The pattern correction method of claim 2, 3, 9 or 10, wherein the photoresist pattern is formed in the pattern forming step so that when the photomask is viewed from above, the first portion that has not been removed in the first removal step A part of the 2 pattern forming portion is not adjacent to the first pattern forming portion. The pattern correction method of claim 2, 3, 9 or 10, wherein the first pattern forming part is a first light shielding film having light shielding properties; and the second pattern forming part is a second light shielding film having light shielding properties. The pattern correction method of claim 9 or 10, wherein: the first pattern forming part is a first light shielding film having light shielding properties; the second pattern forming part is a second light shielding film having light shielding properties, in the pattern forming step , when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least a portion of the photoresist film overlapping the first light-shielding film, and the first removal step is performed between the pattern forming step and the etching stop film removal step. In the etching stop film removal step, the photoresist pattern is used as a mask and the etching stop film is removed. After the etching stop film removal step, a second removal step is also included. The second removal step The photoresist pattern is used as a mask and a part of the first light-shielding film is removed. The pattern correction method of claim 2, 3, 9 or 10, wherein: the first pattern forming part includes a semi-transmissive film and a first light-shielding film or a phase shift film, and the first light-shielding film is arranged between the semi-transmissive film and the A part of the area between the transparent substrates has light-shielding properties, and the second pattern forming portion is a second light-shielding film having light-shielding properties. Such as requesting the pattern correction method of item 9 or 10, wherein: The first pattern forming part includes a semi-transmissive film and a first light-shielding film or phase shift film. The first light-shielding film is disposed on a part of the area between the semi-transmissive film and the transparent substrate and has light-shielding properties. , the second pattern forming part is a second light-shielding film having light-shielding properties. In the pattern forming step, when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least the first light-shielding film or the phase shift The first removal step is performed between the pattern forming step and the etch stop film removal step, and the photoresist pattern is used as a mask in the etch stop film removal step. Removing the etch stop film, after the etch stop film removal step, also includes: a second removal step, using the photoresist pattern as a mask and removing a part of the semi-transmissive film; and a third removal step, using the photoresist pattern The pattern is used as a mask to remove part of the first light-shielding film or the phase shift film. The pattern correction method of claim 2, 3, 9 or 10, wherein: the first pattern forming part includes a phase shift film, and the second pattern forming part includes a phase shift film or a second light shielding film having light shielding properties. The pattern correction method of claim 9 or 10, wherein: the first pattern forming part includes a phase shift film; the second pattern forming part includes a phase shift film or a second light shielding film with light shielding properties, in the pattern forming step , when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least a portion of the photoresist film that overlaps the phase shift film, and the first removal step is between the pattern forming step and the etch stop film removal step. In the etching stop film removal step, the photoresist pattern is used as a mask, and the etching stop film is removed. After the etching stop film removal step, a second removal step is also included, and the second removal step is The photoresist pattern serves as a mask and removes a portion of the phase shift film. The pattern correction method of claim 9 or 10, wherein: the first pattern forming part includes a semi-permeable film or a phase shift film formed on a transparent substrate; and has a mask. An optical first light-shielding film is laminated on a part of the surface of the semi-permeable film or the phase shift film on the opposite side to the transparent substrate side through a second etching stop film, and the second pattern is formed This is a second light-shielding film that has light-shielding properties. The pattern correction method of claim 20, wherein: in the pattern forming step, when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least a portion of the photoresist film overlapping the first light-shielding film, the The first removal step is performed between the pattern forming step and the etch stop film removal step. In the etch stop film removal step, the photoresist pattern is used as a mask and the etch stop film is removed. After the removal step, it also includes: a second removal step, using the photoresist pattern as a mask and removing a part of the first light-shielding film; a third removal step, using the photoresist pattern as a mask and removing the second etching stop a part of the film; and a fourth removal step, using the photoresist pattern as a mask and removing a part of the semi-transmissive film or the phase shift film. The pattern correction method of claim 2, 3, 9 or 10, wherein: the first pattern forming part includes: a semipermeable film or a phase shift film, and the semipermeable film or phase shift film is composed of the first material and the A third material different from the second material is formed on the transparent substrate; and a first light-shielding film with light-shielding properties is laminated on the side of the semi-transmissive film or the phase shift film opposite to the transparent substrate. The second pattern forming part is a second light-shielding film having light-shielding properties on a part of the surface of the side. The pattern correction method of claim 9 or 10, wherein: the first pattern forming part includes: a semipermeable film or a phase shift film, and the semipermeable film or phase shift film includes a material different from the first material and the second material. a third material formed on the transparent substrate; and a first light-shielding film having light-shielding properties, the first light-shielding film being laminated on the surface of the semi-permeable film or the phase shift film opposite to the transparent substrate side. In some areas, The second pattern forming part is a second light-shielding film having light-shielding properties. In the pattern forming step, when the photomask is viewed from above, the photoresist pattern is formed so as to remove at least the portion of the photoresist that overlaps the first light-shielding film. a part of the film, the first removal step is performed between the pattern forming step and the etch stop film removal step, in the etch stop film removal step, the photoresist pattern is used as a mask, and the etch stop film is removed, After the etching stop film removal step, it also includes: a second removal step, using the photoresist pattern as a mask and removing a part of the first light-shielding film; a third removal step, using the photoresist pattern as a mask and removing The semipermeable membrane or a part of the phase shift membrane. A photomask to which a new pattern is added, the photomask having a first pattern formed on a transparent substrate using a first pattern forming portion containing a first material, and having: the first pattern ; and a second pattern, a pattern formed on the transparent substrate such that it is adjacent to and in contact with the first pattern when the photomask is viewed from above, wherein it is composed of a second pattern containing a second material different from the first material. 2 pattern forming part is formed. A photomask to which a new pattern is added, the photomask having a first pattern formed on a transparent substrate using a first pattern forming portion containing a first material, and having: the first pattern ; And the second pattern is a pattern formed on the transparent substrate so that it is not adjacent to the first pattern when the photomask is viewed from above, wherein the second pattern includes a second material different from the first material. The forming part is formed. A photomask to which a new pattern is added, the photomask having a first pattern formed on a transparent substrate using a first pattern forming portion containing a first material, and having: the first pattern ; and a second pattern, a pattern formed on the transparent substrate such that it is adjacent to the first pattern when the photomask is viewed from above, including an etching stop film and a second pattern containing the same metal as the first material. 2 materials The 2nd pattern forming part is formed. A photomask to which a new pattern is added, the photomask having a first pattern formed on a transparent substrate using a first pattern forming portion containing a first material, and having: the first pattern ; And the second pattern is a pattern formed on the transparent substrate so that it is not adjacent to the first pattern when the photomask is viewed from above, and is composed of an etching stop film and a second pattern containing the same metal as the first material. A second pattern forming portion of 2 materials is formed.

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