JP4408732B2 - Method for forming hole pattern - Google Patents

Description

  The present invention relates to a hole pattern forming method using a halftone phase shift mask.

In the photolithography process, a halftone phase shift mask is used to improve the resolving power (see, for example, Patent Document 1).
However, when exposure is performed using a halftone phase shift mask 31 in which an opening 312 is formed in a semitransparent film 311 as shown in FIG. 17A, depending on the exposure conditions, as shown in FIG. Thus, not only the opening 322 due to the main peak transmitted through the opening 312 on the wafer but also a sub-peak of light intensity at a position separated from the opening 322 by a resolution limit 324 represented by the light source wavelength / projection lens numerical aperture NA. As a result, an opening (also referred to as “side lobe”) 323 due to the sub-peak is formed.

  Conventionally, a method has been proposed in which hole patterns are formed at a pitch narrower than that of the mask pattern by performing exposure while shifting the focus using a halftone phase shift mask in which translucent patterns are formed at a pitch equivalent to the exposure wavelength. (For example, refer to Patent Document 2).

JP-A-4-136854 JP-A-9-138497 (page 3-4, FIG. 4-5)

However, the method of exposing while shifting the focus described above has a problem that the contrast of the optical image of the pattern is deteriorated. Therefore, there is a problem that a fine hole pattern cannot be formed by stable exposure.
Furthermore, in a system LSI such as a logic LSI, it is necessary to form not only a dense pattern in which holes are densely arranged but also an isolated pattern in which holes are sparsely arranged. When exposure is performed while shifting the focus as described above, there is a problem in that both dense patterns and isolated patterns cannot be formed with high accuracy.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to form a fine hole pattern by stable exposure. Another object of the present invention is to accurately form both dense patterns and isolated patterns.

The hole pattern forming method according to the present invention includes a main opening due to a main peak of transmitted light transmitted through a first opening densely formed on a halftone phase shift mask, and a second due to a side peak of the transmitted light. A method of forming a hole pattern having an opening,
Forming a resist film on the substrate;
After calculating the size of the first opening so that the dimensional difference between the main opening and the second opening is minimized when exposure is performed using illumination with a coherence factor of 0.3, the calculated size Correcting the illumination coherence factor so that a dimensional difference between the main opening and the second opening is minimized when exposed using a halftone phase shift mask in which the first opening is formed;
Irradiating the resist film with exposure light through the halftone phase shift mask after correcting the illumination coherence factor;
And a step of forming a hole pattern having a main opening and a second opening by performing a development process after irradiating the exposure light.

The hole pattern forming method according to the present invention includes a main opening due to a main peak of transmitted light transmitted through a first opening densely formed on a halftone phase shift mask, and a second due to a side peak of the transmitted light. A method of forming a hole pattern having an opening and a third opening by transmitted light transmitted through a second opening formed isolated on the mask,
Forming a resist film on the substrate;
After calculating the size of the first opening so that the dimensional difference between the main opening and the second opening is minimized when exposure is performed using illumination with a coherence factor of 0.3, the first size is calculated using the calculated size. Correcting the illumination coherence factor so that a dimensional difference between the main opening and the second opening is minimized when exposure is performed using a halftone phase shift mask in which an opening is formed;
Irradiating the resist film with exposure light through the halftone phase shift mask after correcting the illumination coherence factor;
A step of forming a hole pattern having the main opening, the second opening, and the third opening by performing a development process after the exposure light irradiation.

  In the hole pattern forming method according to the present invention, the exposure light is irradiated through a halftone phase shift mask in which a first light-shielding pattern having a dimension of 40 nm to 50 nm is formed at a position corresponding to the second opening. Is preferred.

  In the method for forming a hole pattern according to the present invention, through a halftone phase shift mask in which a second light-shielding pattern having a dimension of 100 nm or more is formed at a position corresponding to the main opening and the second opening that are not required to be formed. It is preferable to irradiate the exposure light.

  In the hole pattern forming method according to the present invention, the exposure light may be irradiated through a halftone phase shift mask in which an opening having a dimension of about 20 nm is formed at a position corresponding to the second opening. Is preferred.

  In the hole pattern forming method according to the present invention, it is preferable that the coherence factor of the illumination is corrected within a range of 0.2 to 0.4.

  According to the present invention, a fine hole pattern having a main opening and a second opening can be formed by stable exposure. Further, according to the present invention, it is possible to accurately form both a dense pattern composed of the main opening and the second opening and an isolated pattern composed of the third opening.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof may be simplified or omitted.

The hole pattern design rule in a 45 nm node system LSI is expected to be about 80 nm in hole diameter and about 150 nm in hole pitch (hereinafter referred to as “pitch”). The current state-of-the-art photolithography exposure apparatus is an F ₂ excimer laser exposure apparatus having a lens numerical aperture NA = 0.8 using an F ₂ excimer laser having a wavelength of 157.6 nm as a light source. Since the standard of the limit of the pitch is calculated by the wavelength / numerical aperture of the exposure apparatus, the limit of the pitch when using the F ₂ excimer laser exposure apparatus is about 197 nm.

In response to the above, the present inventor performed a detailed simulation on the pitch dependence of the resolution performance of patterning. In the simulation, an index called NILS (Normalized Image Log-Slope) was used. The larger the NILS value, the smaller the dimensional variation per exposure error, indicating that more stable patterning is possible. According to intensive studies by the present inventor, it has been found that the standard for stable patterning by F ₂ lithography is NILS> 1.8.
When NILS for patterning a hole having a hole diameter of 80 nm was calculated under the conditions of the light source wavelength λ = 157.6 nm, the lens numerical aperture NA = 0.8, and the illumination σ (coherence factor) = 0.3, the pitch was 200 nm. NILS was 1.89, and NILS at a pitch of 190 nm was 1.71. This is a result of supporting the limit pitch 197 nm obtained from the above-mentioned wavelength / numerical aperture.
As a technique for further reducing the pitch, there is a method of changing the coherence factor σ of illumination light, that is, a method using a modified illumination method. When NILS at the time of patterning a hole having a hole diameter of about 80 nm was calculated using annular illumination (annular ratio 3/4) of σ = 0.85, NILS at a pitch of 170 nm was 1.97. The NILS at a pitch of 160 nm was 1.75. Therefore, it is expected that the limit pitch is improved to a little over 160 nm by using annular illumination instead of normal illumination. However, it does not reach the limit pitch of 150 nm required for the 45-nm node system LSI. Further, the NILS when exposing an isolated hole using annular illumination was estimated to be only 1.14.
In order to facilitate understanding of the contents of the present invention, the pitch and hole diameter on the mask in this specification are values obtained by dividing the pitch and hole diameter on the actual mask by the transfer rate.

Embodiment 1 FIG.
FIG. 1 is a diagram for explaining a hole pattern formed in the first embodiment of the present invention. Specifically, FIG. 1A is a plan view for explaining a hole pattern, and FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. FIG. 2 is a plan view for explaining a halftone phase shift mask used for forming the hole pattern shown in FIG.
As shown in FIG. 1, a hole pattern 11 made of a resist formed on a substrate 10 includes a dense pattern in which openings 112a and 112b are densely arranged at a narrow pitch 114, and an isolated pattern in which openings 113 are sparsely arranged. And have. The dense pattern includes a main opening 112a resolved by the main peak of the transmitted light transmitted through the opening 212 formed densely in the mask, and a second opening (side lobe) resolved by the side peak of the transmitted light. 112b. The second opening 112b is formed at a position surrounded by the main opening 112a on the four sides of the upper, lower, left, and right sides at equal distances, that is, at the center of the four points of the main opening 112a. The openings 112a and 112b are formed at a pitch 114 that is 1 / √2 times or more and less than 1 time the resolution limit expressed by wavelength / numerical aperture. On the other hand, the isolated pattern is composed of the third opening 113 resolved by the transmitted light transmitted through the opening 213 sparsely formed in the mask.

  As shown in FIG. 2, the halftone phase shift mask 21 is formed with a translucent film 211 having a light transmittance of 0 to 20% on a transparent substrate (not shown). Openings 212 corresponding to the main openings 112a are formed in a region of the semitransparent film 211 at a pitch 214 that is not less than 1 and less than √2 times the resolution limit represented by the wavelength / lens numerical aperture of the exposure apparatus. In another region, an opening 213 corresponding to the third opening 113 is formed. By forming the openings 212 with such a pitch 214, the openings 112a and 112b can be formed with a pitch of 1 / √2 times or more and less than 1 times the resolution limit as described above.

  In the first embodiment, the side peak of the mask transmitted light is intentionally generated by reducing the illumination σ and the size of the opening on the mask (hereinafter referred to as “mask size”). Two openings 112b are formed. Further, the present inventor optimizes the illumination σ and the mask size as will be described later, so that the dense pattern composed of the main opening 112a and the second opening 112b equivalent to the main opening 112a, and the third opening It has been found that an isolated pattern consisting of 113 can be formed.

FIG. 3 is a flowchart for explaining an optimization method of illumination σ and mask size in the first embodiment.
First, a pattern group X to be evaluated in detail is selected from the dense patterns shown in FIG. 1 (first step S11). Here, the pattern group X is a pattern group including at least a second opening 112b and a main opening 112a surrounding four sides of the second opening 112b. That is, the pattern group X is a pattern group that includes at least 3 × 3 openings 112a and 112b centered on the second opening 112b.

Next, when the selected pattern group X is exposed with illumination σ = 0.3, a mask size Y that minimizes the dimensional difference between the main opening and the second opening in the pattern group X is calculated by aerial image simulation (first). 2 step S12). The mask size Y refers to the dimension of the opening 212 formed in the halftone phase shift mask 21.
Here, the inventor investigated the illumination σ dependency of the resolution peak (that is, the side peak) of the second aperture. FIG. 4 is a diagram illustrating the relationship between the resolution peak of the second opening and the illumination σ. As shown in FIG. 4, it was found that the value of the resolution peak of the second aperture hardly changes when the illumination σ is a value from 0 to 0.3. Therefore, when the illumination σ is small, no change in the resolution peak is observed even when the illumination σ is adjusted, and it is difficult to adjust the resolution peak of the second aperture, and there is a problem of speckle and aberration. I understood that. On the other hand, when the illumination σ exceeds 0.3, the resolution peak of the second aperture is lowered, and the second aperture is not resolved. Therefore, it was found that the optimal illumination σ for performing the aerial image simulation is 0.3. Furthermore, as a result of examining the relationship between the second aperture resolution peak and the illumination σ for the holes with various pitches, the inventor found that the optimum illumination σ for performing the aerial image simulation is 0.3. I found out.

  Next, a halftone phase shift mask is produced with the calculated mask size Y. Then, the main aperture and the second aperture are exposed using the produced halftone phase shift mask, and the illumination σ is corrected so that the dimensional difference between the main aperture and the second aperture is minimized (third step S13). . Here, in consideration of the resolution peak of the second opening, the range in which the illumination σ is corrected is set to 0.2 or more and 0.4 or less.

  As a result of optimizing the illumination σ and the mask size by the above three steps, in order to form a dense hole pattern with a light source wavelength λ = 157.6 nm, a lens numerical aperture NA = 0.8, and a hole diameter = 0.80, The optimum combination of illumination σ and mask size is, for example, illumination σ: mask size = (0.20: 94 nm), (0.25: 94 nm), (0.30: 94 nm), (0.35: 92 nm) ), (0.40: 90 nm).

  As described above, a resist film is formed on the substrate 10, the mask size is calculated and the illumination σ is corrected, and then the exposure light is irradiated to the resist film through the halftone phase shift mask. . Thereafter, by performing development processing, the dense pattern composed of the main opening 112a due to the main peak of the transmitted light of the mask opening 212 and the second opening 112b due to the sub-peak of the transmitted light, and the transmitted light of the mask opening 213 An isolated pattern including the third opening 113 can be formed. Since it is not necessary to perform multiple exposures with different focal points, a hole pattern can be formed with stable exposure.

  Next, examples showing the first embodiment more specifically will be described. In FIG. 1, dense holes are formed at a specific pitch, but various pitch / layout patterns are mixed in an actual device. In this embodiment, a dense hole with a pitch of 150 nm, a dense hole with a pitch of 160 nm, and an isolated hole are formed at the same time.

FIG. 5 is a plan view for explaining hole patterns formed in the example of the first embodiment. FIG. 6 is a plan view for explaining a halftone phase shift mask used for forming the hole pattern shown in FIG.
As shown in FIG. 5, the hole pattern 12 includes, for example, a first dense pattern in which the main openings 122a and the second openings 122b are densely arranged at a pitch 124 of 150 nm, and a main opening 125a and a pitch 127 of 160 nm, for example. A second dense pattern in which the second openings 125b are densely arranged and an isolated pattern in which the openings 123 are sparsely arranged. In the first and second dense patterns, the main openings 122a and 125a are openings resolved by the main peak of the transmitted light transmitted through the openings 222 and 225 formed in the mask 22, and the second openings 122b and 125b. Is an aperture (side lobe) resolved by the side peak of the transmitted light. The second openings 122b and 125b are formed at positions that are equidistantly surrounded by the main openings 122a and 125a in four directions, that is, four main points of the main openings 122a and 125a. The hole diameters of the main openings 122a and 125a are about 80 nm, and the hole diameters of the second openings 122b and 125b are about 80 nm, equivalent to the main openings 122a and 125a.

  As shown in FIG. 6, the halftone phase shift mask 22 is formed by forming a translucent film 221 having a light transmittance of 0 to 20% on a transparent substrate (not shown). A plurality of openings 222 are densely formed with a pitch 224 of 212 nm, for example, in a region of the semitransparent film 221, and a plurality of openings 225 are densely formed with a pitch 226 of 226 nm, for example, in another region. Further, openings 223 are formed sparsely in another region. The mask 22 is formed so that the phase difference between the light transmitted through the translucent film 221 and the light transmitted through the openings 222, 225, and 223 is 180 degrees. The 212 nm pitch and 226 nm pitch on the mask 22 correspond to the 150 nm and 160 nm pitches of the dense hole pattern on the wafer.

Next, a mask size and illumination σ optimization method according to this embodiment will be described with reference to FIGS.
First, as a first step, a pattern group (group) XA including a 150 nm pitch main opening 122a and a 150 nm pitch second opening 122b and a pattern group XB including a 160 nm pitch main opening 125a and a 160 nm pitch second opening 125b are selected. To do. That is, a dense pattern including four types of openings 122a, 122b, 125a, and 125b is selected.

  Next, as a second step, when the two selected pattern groups XA and XB are exposed with illumination σ = 0.3, a mask size that minimizes the dimensional difference between the four types of openings 122a, 122b, 125a, and 125b. (Dimensions of the openings 222, 225, and 223) are calculated by aerial image simulation. The mask size calculated by the simulation was 94 nm.

  Next, a halftone phase shift mask is produced with the calculated mask size. Then, as a third step, the main aperture and the second aperture are exposed using the produced halftone phase shift mask, and the illumination σ is corrected so that the dimensional difference between the four types of apertures is minimized. In this embodiment, the illumination σ that minimizes the dimensional difference is 0.3, and no correction is necessary.

  Note that the mask size of each pitch including isolated holes may be changed after the illumination σ is corrected. In this case, it is necessary to prepare a halftone phase shift mask again, but the mask sizes of the openings 222 having a pitch of 150 nm, the openings 225 having a pitch of 160 nm, and the openings 223 are set to 94 nm, 92 nm, and 93 nm (wafer conversion). By changing each, the dimensional difference of five types of opening including the 3rd opening 123 can be made still smaller (10.4 nm). Further, after correcting the illumination σ and changing the mask size by simulation, a halftone phase shift mask may be manufactured.

FIG. 7 is a diagram showing the dimensional difference between the four types of openings when the illumination σ and the mask size are changed in the present embodiment.
As shown in FIG. 7, in the second step, the mask size (= 94 nm) that minimizes the dimensional difference when exposure is performed with illumination having an illumination σ of 0.3 is calculated. In the third step, the calculated mask size is calculated. The illumination σ is corrected so that the dimensional difference is minimized when exposure is performed using a halftone phase shift mask manufactured based on the mask size.

  FIG. 8 is a diagram showing a NILS simulation result in this example. For comparison, FIG. 8 shows NILS in the case where exposure is performed using annular illumination. By performing the exposure with the illumination σ and the mask size optimized by the present invention, the NILS becomes 2 or more, and the NILS can be dramatically improved for both the dense pattern (pitch 150 nm, 160 nm) and the isolated pattern. It was found that exposure can be performed.

  FIG. 9 is a diagram illustrating the dependency of dimensions on the depth of focus. As shown in FIG. 9, CD-10% or more, that is, 80-8 = 72 nm or more was obtained with respect to a focal depth of −0.15 to 0.15 μm.

Embodiment 2. FIG.
In the first embodiment described above, as shown in FIG. 10, a dimensional difference of about several nm to about 10 nm may remain in the opening. That is, a difference (hereinafter referred to as “residual dimension difference”) may occur between the dimension 133a of the main opening 132a and the dimension 133b of the second opening 132b. Similarly, in the above embodiment, residual dimensional differences may occur in the four types of openings. This residual dimensional difference is at a level that does not hinder the fabrication of a 45 nm node device, but the present inventor has studied a technique for suppressing this residual dimensional difference. The reason why the residual dimension difference occurs is that the wafer finished dimension 133b of the second opening 133b does not simply depend on the mask size.

FIG. 11 is a diagram for explaining a halftone phase shift mask according to the second embodiment of the present invention. More specifically, FIG. 11A is a plan view showing a halftone phase shift mask, and FIG. 11B is a cross-sectional view taken along the line BB ′ of FIG. FIG. 12 is a diagram illustrating a relationship between the dimension of the light shielding pattern and the dimension of the second opening.
As shown in FIGS. 11A and 11B, in the translucent film 231 formed on the transparent substrate 230, an opening 232 is formed at a position corresponding to the main opening, and at a position corresponding to the second opening. A light shielding pattern 233 made of a chromium film or the like is formed. That is, the light shielding pattern 233 is disposed on the semitransparent film 231 between the openings 232 in the vertical or horizontal direction. As shown in FIG. 12, when the dimension of the light shielding pattern 233 is 40 nm to 50 nm, the dimension of the second opening can be set to 80 nm, which is the same as the dimension of the main opening. Therefore, the residual dimensional difference can be suppressed. As shown in the figure, the size of the second opening decreases as the size of the light shielding pattern 233 increases. When the size of the light shielding pattern 233 exceeds 100 nm, the second opening is not formed.
The formation of the light shielding pattern 233 described in the second embodiment may be performed any time before the exposure light is irradiated to the resist film through the halftone phase shift mask. A light-shielding pattern may be formed when the halftone phase shift mask is manufactured after calculating the pattern size, or may be formed after correcting the illumination σ.

Next, a modification of the second embodiment will be described.
FIG. 13 is a plan view for explaining a halftone phase shift mask according to a modification of the second embodiment of the present invention. FIG. 14 is a plan view showing a hole pattern formed in a modification of the second embodiment of the present invention.
As shown in FIG. 13, a light shielding pattern 243 having a size of 40 nm to 50 nm is formed on the mask 24 by the same method as in the second embodiment, and the main opening and / or the second opening is slightly over 100 nm at a position where formation is not required. A light shielding pattern 244 having a size is formed. As described above, by using the light shielding pattern 243 having a dimension of 40 nm to 50 nm and the light shielding pattern 244 having a dimension of 100 nm or more, as shown in FIG. 14, the dimensions of the main opening 141a and the second opening 142b are substantially the same. Thus, the hole pattern 14 having a random layout can be formed.

Embodiment 3 FIG.
As described above, in the first embodiment, by forming the second opening using the side peak, a pattern with a strong 200 nm pitch (wafer conversion) is formed on the mask at a pitch of 150 nm to 160 nm. The Therefore, a pattern with a strong pitch of 200 nm cannot be formed on the wafer as it is, and it is necessary to suppress the formation of the second openings in order to form a pattern with a strong pitch of 200 nm. In addition to the technique according to the modification of the second embodiment described above, the present inventor has found the technique described below.

FIG. 15 is a plan view for explaining a halftone phase shift mask according to the third embodiment of the present invention. FIG. 16 is a diagram illustrating a relationship between the dimension of the fine transmission pattern and the dimension of the second opening.
As shown in FIG. 15, a fine transmissive pattern 253 is arranged at a location corresponding to the unnecessary second opening in the mask 25. That is, a fine opening 253 is formed in the translucent film 251 between the openings 252 corresponding to the unnecessary second openings. As shown in FIG. 16, by forming the dimension of the fine transmission pattern (opening) 253 to 40 nm or more, formation of unnecessary second openings can be suppressed. Therefore, the main openings 252 can be formed with a pitch of 200 nm or more.
The fine transmission pattern 253 described in the third embodiment may be formed at any time before the exposure light is irradiated to the resist film through the halftone phase shift mask. The fine transmission pattern 253 may be formed when the halftone phase shift mask is manufactured after calculating the pattern size, or may be formed after correcting the illumination σ.

It is a figure for demonstrating the hole pattern formed in Embodiment 1 of this invention. It is a top view for demonstrating the halftone type phase shift mask used in order to form the hole pattern shown in FIG. In Embodiment 1 of this invention, it is a flowchart for demonstrating the optimization method of illumination (sigma) and mask size. It is a figure which shows the relationship between the resolution peak of 2nd opening, and illumination (sigma). It is a top view for demonstrating the hole pattern formed in the Example of Embodiment 1 of this invention. It is a top view for demonstrating the halftone type | mold phase shift mask used in order to form the hole pattern shown in FIG. In the Example of Embodiment 1 of this invention, it is a figure which shows the dimensional difference of four types of opening at the time of changing illumination (sigma) and mask size. In the Example of Embodiment 1 of this invention, it is a figure which shows a NILS simulation result. In the Example of Embodiment 1 of this invention, it is a figure which shows the focal depth dependence of a dimension. It is a figure which shows the dimensional difference which remains between a main opening and a 2nd opening. It is a figure for demonstrating the halftone type phase shift mask by Embodiment 2 of this invention. It is a figure which shows the relationship between the dimension of a light shielding pattern, and the dimension of 2nd opening. It is a top view for demonstrating the halftone type | mold phase shift mask by the modification of Embodiment 2 of this invention. It is a top view which shows the hole pattern formed in the modification of Embodiment 2 of this invention. It is a top view for demonstrating the halftone type phase shift mask by Embodiment 3 of this invention. It is a figure which shows the relationship between the dimension of a fine transmissive pattern, and the dimension of 2nd opening. It is a top view for demonstrating generation | occurrence | production of a side lobe.

Explanation of symbols

10 Substrate 11, 12, 13, 14 Hole pattern 21, 22, 23, 24, 25 Halftone phase shift mask 112a, 122a, 125a, 132a Main opening 112b, 122b, 125b, 132b Second opening 113 Third opening ( Isolated hall)
114, 124, 127 pitch 133a, 133b hole diameter 211, 221, 231, 241, 251 translucent film 212, 213, 222, 223, 225, 232, 242, 252 opening 214 pitch 230 transparent substrate 233, 243 light shielding pattern 244 Shading pattern 252 Transmission pattern (opening)

Claims (6)

A method of forming a hole pattern having a main opening due to a main peak of transmitted light transmitted through a first opening formed densely on a halftone phase shift mask and a second opening due to a side peak of the transmitted light. There,
Forming a resist film on the substrate;
After calculating the size of the first opening so that the dimensional difference between the main opening and the second opening is minimized when exposure is performed using illumination with a coherence factor of 0.3, the calculated size Correcting the illumination coherence factor so that a dimensional difference between the main opening and the second opening is minimized when exposed using a halftone phase shift mask in which the first opening is formed;
Irradiating the resist film with exposure light through the halftone phase shift mask after correcting the illumination coherence factor;
Forming a hole pattern having a main opening and a second opening by performing a development process after irradiating the exposure light, and forming a hole pattern. A main opening due to the main peak of the transmitted light that has passed through the first opening densely formed on the halftone phase shift mask, a second opening due to the side peak of the transmitted light, and an isolation formed on the mask. Forming a hole pattern having a third opening by transmitted light transmitted through the second opening,
Forming a resist film on the substrate;
After calculating the size of the first opening so that the dimensional difference between the main opening and the second opening is minimized when exposure is performed using illumination with a coherence factor of 0.3, the first size is calculated using the calculated size. Correcting the illumination coherence factor so that a dimensional difference between the main opening and the second opening is minimized when exposure is performed using a halftone phase shift mask in which an opening is formed;
Irradiating the resist film with exposure light through the halftone phase shift mask after correcting the illumination coherence factor;
And forming a hole pattern having the main opening, the second opening, and the third opening by performing a development process after the exposure light irradiation. In the formation method of the hole pattern of Claim 1 or 2,
A method for forming a hole pattern, comprising: irradiating the exposure light through a halftone phase shift mask in which a first light-shielding pattern having a dimension of 40 nm to 50 nm is formed at a position corresponding to the second opening. In the formation method of the hole pattern of Claim 1 to 3,
The exposure light is irradiated through a halftone phase shift mask in which a second light-shielding pattern having a dimension of 100 nm or more is formed at a position corresponding to the main opening and the second opening that are not required to be formed. A method of forming a hole pattern. In the formation method of the hole pattern of Claim 1 or 2,
A method of forming a hole pattern, wherein the exposure light is irradiated through a halftone phase shift mask in which an opening having a dimension of about 20 nm is formed at a position corresponding to the second opening. In the formation method of the hole pattern in any one of Claim 1 to 5,
A method for forming a hole pattern, wherein the coherence factor of the illumination is corrected within a range of 0.2 to 0.4.

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