JP2003248296A - Exposure mask and method of manufacturing the same, and method of forming transfer pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure mask which can form a design pattern having roughness and fineness in compliance with design data with good accuracy and a method of manufacturing the same, and a method of forming a transfer pattern using this exposure mask. <P>SOLUTION: The exposure mask which is used for transferring the design pattern 31 having the roughness and fineness onto a substrate 1 and consists of the first exposure mask 21 formed with a dummy pattern 32 in the coarse region of the design pattern 31 together with the design pattern 31 and the second exposure mask 22 formed with the inversion pattern 33 of the dummy pattern 32, the method of manufacturing the same and the method of forming the transfer pattern using this exposure mask. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure mask, a method for manufacturing the same, and a method for forming a transfer pattern. More specifically, the present invention relates to an exposure mask and a method for forming a transfer pattern. The present invention relates to an exposure mask to be used, a method for manufacturing the same, and a method for forming a transfer pattern by transferring a design pattern onto a substrate using the exposure mask.

[0002]

2. Description of the Related Art At present, in lithography technology for forming a circuit pattern of a semiconductor device on a substrate such as a wafer,
A method of forming a transfer pattern on a substrate by reducing exposure using an exposure mask on which a design pattern is formed has become the mainstream. Such exposure reduction rate is 1/5
Alternatively, 1/4 is used as the exposure wavelength, and I-line (365 nm) or far-ultraviolet light (248 nm, 193 nm) is adopted. With the further miniaturization of semiconductor devices, it will be 15 in the future.
Exposure wavelengths such as 7 nm are also expected to be adopted.

Further, in order to improve the resolution at the time of exposure in response to the miniaturization of semiconductor elements, an electron beam projection exposure method (Low
Energy Electron Projection Lithography (LEEP
L), Electron Projection Lithography (EPL)) and ultra-short wavelength UV exposure method (Extreme Ultra Violet Lithograp)
Exposure methods such as hy (EUVL) have also been developed.

In any of the above cases, an exposure mask serving as an original plate for transferring the design pattern onto the substrate is required. This exposure mask has, for example, a circuit pattern design pattern made of a light-shielding film formed on a transparent substrate, and the design pattern is drawn on a resist applied on the light-shielding film with an electron beam and developed to form a resist pattern. After forming
It can be obtained by etching using this resist pattern.

In lithography for forming a circuit pattern on a substrate, the line width accuracy of a design pattern formed on an exposure mask has a great influence on the line width of a transfer pattern transferred on the substrate. Therefore, the manufacturing technique of the exposure mask in which the design pattern is formed with high precision according to the design data is becoming more important.

[0006]

However, if the design patterns differ in density, not only the proximity effect of the electron beam occurs at the time of electron beam drawing at the time of manufacturing the exposure mask, but also at the time of development or etching after drawing. Since a so-called loading effect sometimes occurs, there is a problem in that the pattern line width varies and it is difficult to accurately form a design pattern on the exposure mask. Furthermore, by exposing using the above-mentioned exposure mask and transferring the design pattern onto the substrate,
The variation of the line width of the transfer pattern formed on the substrate increases, and it is difficult to obtain a desired transfer pattern.

[0007]

In order to solve the above-mentioned problems, an exposure mask of the present invention is an exposure mask used when transferring a sparse and dense design pattern onto a substrate. It is characterized by comprising a first exposure mask having a dummy pattern formed in a sparse region and a second exposure mask having an inverted pattern of the dummy pattern.

The present invention is also a method of manufacturing the above-mentioned exposure mask, which comprises a step of extracting a sparse region of a design pattern,
A step of manufacturing a first exposure mask in which a dummy pattern is formed in a sparse region of the design pattern together with a design pattern, and a step of manufacturing a second exposure mask in which a reverse pattern of the dummy pattern is formed Is characterized by.

Furthermore, the present invention is also a method of forming a transfer pattern using the above-mentioned exposure mask, which is a method of forming a transfer pattern by transferring a sparse and dense design pattern onto a substrate. First to layer
It is characterized in that the exposure using the second exposure mask and the exposure using the second exposure mask are performed.

According to the exposure mask and the method of manufacturing the exposure mask as described above, the first exposure mask has the dummy pattern formed in the sparse region of the design pattern together with the design pattern. It is possible to reduce the difference in the density of the patterns in the exposure mask, and to make the pattern density more uniform. This allows
Since the electron beam proximity effect at the time of manufacturing the first exposure mask and the loading effect at the time of development and etching can be suppressed, it is possible to suppress the variation of the pattern line width in the first exposure mask, The design pattern can be formed accurately according to the design data.

Further, a reverse pattern of the dummy pattern in the first exposure mask is formed on the second exposure mask. Thus, when the design pattern is transferred onto the substrate using the first exposure mask, the dummy pattern transferred onto the substrate can be erased by further using the second exposure mask.

Further, according to the above-described method of forming a transfer pattern using the exposure mask, the transfer pattern forming layer on the substrate is exposed using the first exposure mask and the second exposure mask. Do exposure. Here, as described above, since the design pattern is formed on the first exposure mask with high precision according to the design data, by performing exposure using the first exposure mask, the precision with respect to the design data is improved. A high transfer pattern can be formed on the substrate, and by exposing using a second exposure mask,
The dummy pattern transferred together with the design pattern can be erased.

Another exposure mask of the present invention is an exposure mask used for transferring a sparse / dense design pattern onto a substrate, and is divided in a complementary manner so as to reduce the sparse / dense difference in the design pattern. It is characterized by comprising a plurality of exposure masks each having a design pattern formed thereon.

The present invention is also a method of manufacturing the above-mentioned exposure mask, wherein the design pattern is complementarily divided so that the density difference of the design patterns is reduced, and a plurality of exposures in which the divided design patterns are formed respectively. It is characterized by manufacturing a mask.

Furthermore, the present invention is also a method of forming a transfer pattern using the above-mentioned exposure mask, wherein a plurality of exposure masks are used one by one, and the transfer pattern forming layer on the substrate is exposed a plurality of times. It has a feature.

According to the exposure mask and the method of manufacturing the exposure mask as described above, the plurality of exposure masks are formed and the complementary divided design patterns are formed so as to reduce the density difference of the design patterns. Therefore, the pattern density of each exposure mask can be made more uniform. Thereby, the electron beam proximity effect at the time of manufacturing the exposure mask and the loading effect at the time of development and etching can be suppressed, so that the variation of the pattern line width in the exposure mask can be suppressed and the divided design The pattern can be accurately formed according to the design data.

Further, according to the above-described method of forming a transfer pattern using the exposure mask, a plurality of exposure masks in which the design pattern is divided in a complementary manner are used one by one with respect to the transfer pattern forming layer on the substrate. Perform multiple exposures. With this, in each exposure mask, the divided design pattern is formed with high accuracy according to the design data, so that the transfer pattern with high accuracy with respect to the design data can be formed on the substrate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The method and structure for manufacturing the exposure mask according to the present invention will be described with reference to FIGS. 2 to 4 in the order of the flowchart shown in FIG. 2 is design data, FIG. 3 is a plan view of the first exposure mask (a) and an AA ′ cross-sectional view (b), and FIG. 4 is a plan view of the second exposure mask (a) and B. -B 'sectional drawing (b) is each shown. Further, the flowchart of FIG. 1 shows a step (S) when manufacturing an exposure mask and setting items (DT) in each step.

The design data 30 of FIG. 2 represents design data of a circuit pattern of a semiconductor device, for example. Here, an exposure mask for forming a circuit pattern on the substrate according to the design pattern 31 indicated by the design data 30 will be described according to its manufacturing procedure. First, as shown in the design data 30, the area in which the design pattern 31 is arranged is divided into meshes 41 according to a preset mesh size (DT101) (S201).

Here, if the mesh size is set finely, the density information of the design pattern 31 can be obtained more accurately, but since the calculation takes time, the accuracy and time are taken into consideration for the adjustment. In the present embodiment, for example, the mesh size is set to be approximately the same as the longest part of the design pattern 31 in the area, but the present invention is not limited to this, and the design pattern is set so that sufficient accuracy can be obtained and processing time can be suppressed. Three
It is preferable to set the mesh size according to the pattern size of 1.

Then, the inside of each mesh 41 is scanned to detect a sparse area of the design pattern 31 (S202). Specifically, the pattern density of each mesh 41 is calculated. The pattern density here is the area content rate of the design pattern 31 formed in the mesh 41. Further, the inside of each mesh 41 is scanned to detect a blank area where the design pattern 31 is not formed.

Then, the mesh 41 having the pattern density of less than 20% or the mesh 41 having a blank area of a predetermined size or more is extracted as the correction mesh 42 (S203). In this embodiment, the pattern density is 20%.
Mesh 41 having blank areas A and D that are smaller than or equal to a predetermined size, pattern density is less than 20%, mesh 41 that has a blank area B that is smaller than a predetermined size, and pattern density is at least 20% and a predetermined size. The mesh 41 having the above blank area C is extracted as the correction mesh 42.

Then, the blank area A of the correction mesh 42,
A dummy pattern 32 to be formed on B, C and D is designed (S204). The dummy pattern 32 is designed according to a predetermined design rule (DT103) such as the length and width of the pattern and the distance between the patterns.

Then, as shown in FIG. 3A, the design pattern 31 is formed, and the sparse region of the design pattern 31, that is, the blank regions A, B, C, D of the correction mesh 42 shown in FIG. A dummy pattern 32 is formed on
The first exposure mask 21 is manufactured (S301).

Specifically, as shown in FIG. 3B, a negative resist (not shown) is applied to a transparent substrate 24 made of, for example, glass on which a light shielding film 23 made of, for example, a chromium thin film is formed. Then, the design pattern 31 and the dummy pattern 32 are drawn on the negative resist by the electron beam. Here, since the negative type resist is used, the resist in the region drawn by the electron beam is polymerized. Then, by developing, the resist other than the region drawn by the electron beam is removed, and the light-shielding film 23 in the part where the resist is removed is removed by etching so that the design pattern 31 and the dummy pattern 32 become non-exposed parts. The first exposure mask 21 formed on the substrate is manufactured.

Further, as shown in FIG. 4A, an inversion pattern 33 which becomes an erase pattern of the dummy pattern 32.
Are designed (S205), and the second exposure mask 22 on which the inverted pattern 33 is formed is manufactured (S302). Here, since the dummy pattern 32 is erased when the design pattern 31 is transferred onto the substrate, the positional deviation when exposing the substrate using the first exposure mask 21 and the second exposure mask 22 is also taken into consideration. A margin (DT 104) is provided in the line width of the inverted pattern 33 so that the dummy pattern 32 can be surely erased. Therefore, the reverse pattern 33 of the second exposure mask 22 has a line width and length slightly larger than the dummy pattern 32 of the first exposure mask 21. At this time, this margin is minimized so that the design pattern 31 formed in proximity to the dummy pattern 32 is not affected by the optical proximity effect when the substrate is exposed using the second exposure mask 22. It is preferable to set.

As a specific method for manufacturing the second exposure mask 22, as shown in FIG. 4B, the light shielding film 23 is formed because the inverted pattern 33 of the dummy pattern 32 is formed on the second exposure mask 22. A positive resist (not shown) is applied to the transparent substrate 24 on which is formed, and an inversion pattern 33 is drawn on the positive resist by an electron beam. As a result, the drawn portion is modified so that it becomes soluble in the developing solution. Therefore, after development, by removing the light shielding film 23 in the region where the resist is removed by etching, the reversal pattern 33 becomes the exposed portion. The second exposure mask 22 formed on the substrate is obtained.

Since the second exposure mask 22 has only the inversion pattern 33 and thus has a difference in the density of the patterns, it has an electron beam proximity effect at the time of electron beam drawing and at the time of development. Also, a loading effect occurs during etching, but since the second exposure mask 22 is used for erasing the dummy pattern 32, the second exposure mask 22 is not required to have the same accuracy as the first exposure mask 21, so there is no problem. As described above, the exposure mask including the first exposure mask 21 and the second exposure mask 22 as a set is obtained.

According to such an exposure mask and the method of manufacturing the exposure mask, the first exposure mask 21 has the design pattern 31 and the sparse regions (blank regions A, B, C, D) of the design pattern 31. Since the dummy pattern 32 is formed, the density difference of the patterns of the first exposure mask 21 is reduced, and the pattern density becomes more uniform. As a result, the electron beam proximity effect in electron beam writing when forming the design pattern 31 and the dummy pattern 32 on the first exposure mask 21 and the loading effect during development and etching can be suppressed. The width variation can be suppressed, and the design pattern 31 can be accurately formed on the first exposure mask 21 according to the design data 30.

On the other hand, since the inverted pattern 33 of the dummy pattern 32 is formed on the second exposure mask 22,
Design pattern 3 using the first exposure mask 21 on the substrate
When 1 is transferred, the dummy pattern 32 can be erased by further using the second exposure mask 22.

Next, a method of forming a transfer pattern using the first exposure mask 21 and the second exposure mask 22 of the present invention will be described in detail. FIG. 5 shows a sectional process drawing in the transfer pattern forming method of the present invention.

First, as shown in FIG. 5A, the substrate 11
A processed film 12 to be patterned is formed on the resist, and a resist (transfer pattern forming layer) 13 made of a positive resist is applied on the film. Next, the first exposure mask 21 is placed above the resist 13 and exposed with the exposure light 51. Here, the design pattern 31 and the dummy pattern 32 having sparseness and denseness are formed on the first exposure mask 21 so as to be non-exposed portions.

After the exposure, the design pattern 31 and the dummy pattern 32 in the first exposure mask 21 are transferred to the resist 13. Here, since the resist 13 is a positive type resist, the exposed portion is modified into a structure soluble in a developing solution, and the non-exposed portion is formed as a transfer pattern.

Next, as shown in FIG. 5B, a second exposure is formed above the resist 13 onto which the design pattern 31 and the dummy pattern 32 have been transferred so that the reversal pattern 33 becomes an exposed portion. The mask 22 is placed and the exposure light 5
1 is used for exposure. Here, the second exposure mask 22 is aligned and exposed so that the inverted pattern 33 overlaps the dummy pattern 32 transferred to the resist 13. At this time, even when a positional deviation occurs within the range of the alignment accuracy of the exposure mask, there is no problem because the reversal pattern 33 is formed with a margin with respect to the dummy pattern 32 as described above. As a result, the region of the resist 13 to which the dummy pattern 32 has been transferred is exposed, and is transformed into a structure soluble in the developing solution.

Then, as shown in FIG. 5C, by developing with a developing solution, the resist 13 (see FIG.
The exposed portion (see (b)) is removed, and the transfer pattern 14 to which the design pattern 31 is transferred is formed. After that, the transfer film 14 is used as a mask to form the film 1 to be processed.
2 is etched to form a circuit pattern (not shown) formed by patterning the film 12 to be processed. This circuit pattern is also formed as a transfer pattern of the design pattern 31.

According to such a method of forming the transfer pattern 14, as described above, the design pattern 31 is accurately formed on the first exposure mask 21 as the design data 30. Therefore, the first exposure mask 21 is formed. Substrate 1 using mask 21
By transferring the design pattern onto the pattern data 1, it is possible to form the transfer pattern 14 and the circuit pattern with high accuracy for the design data 30. Then, by exposing using the second exposure mask 22, the dummy pattern 32 transferred to the resist 13 on the substrate 11 is erased, so that only the transferred design pattern 31 remains on the substrate 11, It becomes the transfer pattern 14.

According to the method as described above, in order to obtain a desired transfer pattern, which has been conventionally performed, the design pattern is corrected in advance by simulation so that the influence of the density difference of the design pattern is reduced. Even in this case, it is not necessary to consider the influence of the density of the design pattern when forming the exposure mask. Therefore, the trouble of correction can be simplified.

In the transfer pattern forming method described above, after the first exposure mask 21 is used for exposure,
Although the exposure is performed using the second exposure mask 22, the present invention is not limited to this, and the first exposure mask 21 may be used for the exposure after the second exposure mask 22 is used. .

In this case, when the second exposure mask 22 formed so that the reversal pattern 33 serves as an exposure portion is disposed above the resist 13 and exposed, the reversal pattern 33 is formed.
The resist 13 in the region to which is transferred is modified and has a structure that is soluble in the developing solution.

Next, the first exposure mask 21 on which the design pattern 31 and the dummy pattern 32 are formed is arranged above the resist 13 and exposed. At this time, when exposure is performed by aligning the position and orientation of the first exposure mask 21 so that the dummy pattern 32 is overlapped with the region to which the reverse pattern 33 is transferred, the resist 13 in the region to which the dummy pattern 32 is transferred is exposed. Since it has already been modified, the dummy pattern 32 is not transferred and only the design pattern 31 is transferred. After that, the transfer pattern 14 is formed by removing the exposed resist 13 using a developing solution. With such a method, the same effect as that of the above-described transfer pattern forming method can be obtained.

(Second Embodiment) Next, a second embodiment of the present invention will be described. In the present embodiment, the method of manufacturing the exposure mask in the present embodiment will be described with reference to FIG. 7 according to the flowchart shown in FIG. Figure 7 (a)
7A and 7B show design data 35, and FIGS. 7B and 7C show plan views of the exposure mask in the present embodiment. The present embodiment is a method of manufacturing a plurality of exposure masks 25 in which patterns are formed by complementarily dividing a design pattern 34 having sparseness and denseness. Here, the design pattern 34 is divided into two, and the divided patterns 34a and 34b are formed.
An example in which the exposure masks 25a and 25b are manufactured will be described.

The design data 35 in FIG. 7A represents, for example, design data of a circuit pattern of a semiconductor device, as in the first embodiment. Here, an exposure mask for forming a circuit pattern on the substrate according to the design pattern 34 indicated by the design data 35 will be described in accordance with its manufacturing procedure. First, as shown in the design data 35, the area in which the design pattern 34 is arranged is divided into meshes 43 according to a preset mesh size (DT201) (S401).

Then, the pattern density (DT202) of each mesh 43 is calculated, and the sparse region (mesh 43a) is calculated.
And a dense area (mesh 43b) (S40)
2). Here, if the pattern density is, for example, less than 20%, a sparse region, and if 20% or more is a dense region, the meshes E, F, G, and H are the mesh 43a, and the other meshes 43 are the mesh 43b. Be sorted into

Next, the mesh 43b is extracted (S40).
3). Then, for example, by scanning the mesh 43b, numbering the patterns of each mesh 43b in the arrangement order, and extracting the odd-numbered pattern in the entire mesh 43b, the design pattern 34 is complemented according to the division rule (DT203). (S404). Here, the pattern 34a is obtained by extracting the odd-numbered patterns in the mesh 43b. Further, the even-numbered pattern in the mesh 43b and the pattern in the mesh 43a are extracted as a pattern 34b.

In the case of a pattern extending over two or more meshes 43, it is considered that the pattern belongs to the mesh 43 having a large included area when the patterns are numbered. Although not illustrated here, when the pattern density in the mesh 43 is 20% or more and one large pattern is formed in one mesh 43, the pattern is divided. In this way, the design pattern 34 is divided into the patterns 34a and 34b in a complementary manner. Note that the division rule is not limited to this, and may be a rule that complementarily divides so that the difference in density of the design patterns 34 is reduced. Further, in order to reduce the density difference, it is preferable that the division rule is such that adjacent patterns are divided and formed on different exposure masks.

Next, the area in which the patterns 34a and 34b obtained by dividing the design pattern 34 are arranged is divided into the same mesh size as the area in which the design pattern 34 is arranged, and the pattern density in the mesh 43 is calculated. (DT204), it is confirmed whether the pattern density is less than 20% (S405), and if the pattern density in the mesh 43 is 20% or more, the mesh 43 is extracted and the same is performed until it becomes less than 20%. Split according to the rules.
Here, the design pattern 34 is divided into two patterns 34a and 34b, but if there is a mesh having a pattern density of 20% or more in the divided state,
Divide into multiple patterns until less than 20%. In addition, the design pattern 34 may be divided into three or more patterns from the beginning, and in this case, the division rule is appropriately set.

Then, as shown in FIGS. 7B and 7C, the exposure mask 25a having the pattern 34a and the exposure mask 25b having the pattern 34b are formed (S406). Exposure masks 25a and 25b here
The manufacturing method of is similar to the method described with reference to FIG. 4, and the exposure masks 25a and 25b are manufactured by forming the patterns 34a and 34b so as to be exposed portions. Although the patterns 34a and 34b are made to be the exposed portions here, the pattern 34a and 34b are formed by the method described with reference to FIG.
You may manufacture so that a and 34b may become a non-exposed part.

When the transfer patterns are formed on the substrate using the exposure masks 25a and 25b, the exposure masks 25a and 25b are used one by one and arranged above the transfer pattern forming layer (resist) on the substrate. Then, the pattern is formed by aligning the position and the orientation, exposing it a plurality of times, and then developing it.

According to the exposure mask and the manufacturing method thereof as described above, the plurality of exposure masks 25a and 25b are manufactured by complementary division into the patterns 34a and 34b so that the density difference of the design pattern 34 is reduced. Therefore, the electron beam proximity effect when manufacturing the exposure masks 25a and 25b and the loading effect during development and etching can be suppressed. As a result, the exposure masks 25a, 25
It is possible to suppress the variation of the pattern line width of the pattern b.
It is possible to accurately form a and 34b according to the design data.

Further, according to the transfer pattern forming method as described above, the exposure masks 25a and 25b in which the patterns 34a and 34b obtained by complementarily dividing the design pattern 34 are accurately formed according to the design data are used. Since the transfer pattern forming layer on the substrate is exposed multiple times,
It is possible to form a transfer pattern of the design pattern 34 with high accuracy on the design data on the substrate.

As described above, in the first and second embodiments, the photomask manufacturing method has been described as an example, but the present invention is not limited to this and E
The same can be applied to the UVL mask, the X-ray lithography mask, and the wafer transfer using these masks. Also,
The second embodiment can also be applied to a method of manufacturing an exposure mask having an opening pattern used for LEEPL, EPL and the like.

Furthermore, the present invention can be applied to the same method when manufacturing a phase shift mask such as a halftone mask or a Levenson mask. In particular, in the case of a Levenson-type mask of the type in which the exposed portion of the substrate is engraved, a pattern is formed after forming a light-shielding film on the transparent substrate, and then a resist mask is used to partially expose the exposed portion of the transparent substrate. By engraving in, the phase difference of the pattern is inverted by 180 ° C. and the resolution is improved. If the present invention is applied to such a mask, not only the pattern line width but also the loading effect during etching when engraving the transparent substrate can be suppressed, and the transparent substrate can be engraved with high accuracy. A remarkable effect such as a stable phase shift effect can be expected.

[0053]

As described above, according to the exposure mask and the method of manufacturing the exposure mask of the present invention, the first exposure mask has the design pattern and the dummy pattern. It is possible to reduce the difference in the density of the patterns in the mask, and it is possible to make the pattern density more uniform. As a result, the electron beam proximity effect when manufacturing the first exposure mask and the loading effect during development and etching can be suppressed, so that the variation of the pattern line width in the first exposure mask can be suppressed, The design pattern can be formed accurately according to the design data.

Further, a reverse pattern of the dummy pattern is formed on the second exposure mask. Thus, when the design pattern is transferred onto the substrate using the first exposure mask, the dummy pattern transferred onto the substrate can be erased by further using the second exposure mask.

Further, according to the transfer pattern forming method using the above-mentioned exposure mask, the transfer pattern forming layer on the substrate is exposed by using the first exposure mask and by using the second exposure mask. The exposure was performed. As a result, the design pattern is accurately formed on the first exposure mask according to the design data. Therefore, by performing the exposure using the first exposure mask, the transfer pattern with high accuracy can be obtained with respect to the design data. Can be formed on a substrate. further,
By exposing using the second exposure mask, the dummy pattern transferred with the design pattern can be erased.

Further, according to another exposure mask and the method of manufacturing an exposure mask of the present invention, a plurality of exposure masks are formed, and complementary divided patterns are respectively formed so as to reduce the density difference of design patterns. Therefore, the pattern density in each exposure mask can be made more uniform. This makes it possible to suppress the electron beam proximity effect at the time of manufacturing the exposure mask and the loading effect at the time of development and etching,
It is possible to suppress the variation of the pattern line width in the exposure mask, and it is possible to form the design pattern with high accuracy according to the design data.

Further, according to the transfer pattern forming method using the above-mentioned exposure mask, the transfer pattern forming layer on the substrate is exposed a plurality of times by using the above-mentioned plurality of exposure masks one by one. . Thus, in each exposure mask, the divided design pattern is formed with high accuracy according to the design data, so that the transfer pattern with high accuracy can be formed with respect to the design data.

[Brief description of drawings]

FIG. 1 is a flowchart for explaining a method of manufacturing an exposure mask according to the first embodiment.

FIG. 2 is design data of a circuit pattern according to the first embodiment.

FIG. 3 is a plan view (a) and a sectional view (b) of a first exposure mask according to the first embodiment.

FIG. 4 is a plan view (a) and a sectional view (b) of a second exposure mask according to the first embodiment.

FIG. 5 is a cross-sectional process diagram illustrating a method of forming a transfer pattern according to the first embodiment.

FIG. 6 is a flowchart for explaining a method of manufacturing an exposure mask according to the second embodiment.

FIG. 7 is design data (a) of a circuit pattern and plan views (b) and (c) of an exposure mask according to the second embodiment.

[Explanation of symbols]

11 ... Substrate, 13 ... Resist (transfer pattern forming layer),
14 ... Transfer pattern, 21 ... First exposure mask, 22 ...
Second exposure mask, 25a, 25b ... Exposure mask, 3
1, 34 ... Design pattern, 32 ... Dummy pattern, 33
… Inversion pattern

Claims (6)

[Claims] 1. An exposure mask used for transferring a sparse / dense design pattern onto a substrate, wherein a first exposure mask is formed with a dummy pattern in a sparse region of the design pattern together with the design pattern, An exposure mask comprising a second exposure mask on which an inverted pattern of the dummy pattern is formed. 2. A method of manufacturing an exposure mask used for transferring a sparse and dense design pattern onto a substrate, the method comprising: extracting a sparse region of the design pattern; and sparsely designing the design pattern together with the design pattern. Of a first exposure mask in which a dummy pattern is formed in various regions, and a second exposure mask in which a reverse pattern of the dummy pattern is formed, Production method. 3. A method of forming a transfer pattern by transferring a sparse and dense design pattern onto a substrate, the transfer pattern forming layer on the substrate, together with the design pattern, in a sparse region of the design pattern. A method for forming a transfer pattern, which comprises performing an exposure using a first exposure mask on which a dummy pattern is formed and an exposure using a second exposure mask on which a reverse pattern of the dummy pattern is formed. 4. An exposure mask used for transferring a sparse / dense design pattern onto a substrate, wherein complementary divided design patterns are formed so as to reduce a sparse / dense difference in the design pattern. An exposure mask comprising a plurality of exposure masks. 5. A method of manufacturing an exposure mask used to transfer a sparse and dense design pattern onto a substrate, wherein the design pattern is complementarily divided to reduce a sparse and dense difference in the design pattern, A method of manufacturing an exposure mask, which comprises manufacturing a plurality of exposure masks each having the divided design pattern formed therein. 6. A method of forming a transfer pattern by transferring a sparse / dense design pattern onto a substrate, wherein complementary design patterns are formed so as to reduce a sparse / dense difference in the design pattern. A method for forming a transfer pattern, which comprises exposing the transfer pattern forming layer on the substrate a plurality of times by using the plurality of exposed exposure masks one by one.