KR20050021353A - Photomask - Google Patents

Abstract

Dummy patterns are formed in the virtual regions 2 and 3 as subpatterns. However, the aperture ratios when only the main patterns of the virtual regions 2 and 3 are formed are 60% and 90%, respectively. The dummy pattern in the virtual region 2 is a square shading pattern having a side length of 0.15 μm, and the dummy pattern in the virtual region 3 is a square shading pattern having a side length of 0.2 μm. The aperture ratios of the virtual regions 2 and 3 are all set to 30%. When exposure using such a photomask is performed, the amount of light generated by the local flare becomes substantially uniform at any point within the range where the exposure light of the photoconductor is irradiated. As a result, even if variation in the line width occurs, the degree becomes uniform throughout the photomask.

Description

Photomask {PHOTOMASK}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photomask used in photolithography performed at the time of manufacturing a semiconductor device, a design method thereof, and a manufacturing method of a semiconductor device using the same.

Various patterns formed on photomasks in the manufacture of semiconductor devices and the like are transferred by photolithography to photosensitive resists formed on substrates. After this transfer, development of the photosensitive resist is performed, and the wiring layer etc. are processed using the pattern of the photosensitive resist as a mask. In such photolithography, a projection exposure apparatus of a refractive optical system or a reflective refractive optical system is used.

However, in such lithography, an optical path different from the design is formed due to reflection, scattering and non-uniformity of the refractive index of the lens material on the surface or inside of the lens, mask, projection lens, etc. of the illumination optical system. Light comes through. This phenomenon is called flare. When flare occurs, the shape and line width of the pattern transferred to the photosensitive resist fluctuate.

Therefore, with respect to the conventional flare, the flare is reduced by a method of coating the surface of the lens, a method of improving the flatness of the lens surface, and the like.

Recently, however, not only flares but also phenomena called local flares have been problematic. This local flare occurs due to the aberration of the exposure machine. If a local flare occurs, a line width fluctuation or the like occurs like the flare. The range where the local flare affects by a certain pattern in the mask is in the range of about 50 μm from the pattern. However, the range in which the local flare affects may change in the future depending on the generation of the exposure machine and the exposure wavelength. In addition, the influence of the local flare varies with the aperture ratio around the pattern, and thus depends on the position on the photomask. For this reason, the variation degree of the line width in a resist pattern changes with position. Therefore, it is very difficult to modify the pattern of the photomask in consideration of the influence of the local flare.

In recent years, the miniaturization and high integration of semiconductor devices are increasing, and with this, shortening of the wavelength of exposure light used by a projection exposure apparatus is progressing. Although the exposure light of 193 nm wavelength is employ | adopted specifically, the method of illuminating according to the opening area of a predetermined pattern differs from the peculiarity of the lens material corresponding to such a short wavelength, and it is a local flare depending on an exposure pattern. The occurrence of is being questioned. Such flares are called local flares and are a major cause of unpredictable changes in the shape and line width of the pattern to be transferred. The aberration of the above-described exposure machine is due to the specificity of the lens material.

1 is a schematic diagram showing the positional relationship between the regions A to C on the photomask.

2A-2C are schematic diagrams illustrating a method of quantifying a local flare.

3 is a graph obtained by the method shown in FIGS. 2A to 2C.

4 is a schematic diagram showing the basic principle of the present invention.

5A to 5D are schematic diagrams showing a photomask according to the first embodiment of the present invention.

6A to 6D are schematic diagrams showing a photomask according to a second embodiment of the present invention.

7A to 7D are schematic diagrams showing a photomask according to a third embodiment of the present invention.

8A to 8D are schematic diagrams showing a photomask according to a fourth embodiment of the present invention.

9A to 9D are schematic diagrams showing a photomask in which the positive type / negative type is inverted with respect to the first embodiment.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a photomask, a design method thereof, and a method of manufacturing a semiconductor device using the same, which can suppress a difference in the variation in the line width caused by local flare.

As a result of earnestly examining the present inventors, the inventors of the present application have given various aspects of the invention shown below.

The first photomask according to the present invention is directed to a photomask used in which a main pattern to be transferred to a photosensitive member is formed and used for manufacturing a semiconductor device. When the photomask is capable of transferring to the photosensitive member, a plurality of sub-patterns are formed at random, and at least the irradiation area to which irradiated light is to be irradiated is divided into a plurality of virtual regions having a certain shape. The aperture ratio is substantially constant between the plurality of virtual regions.

In the second photomask according to the present invention, the lower the amount of decrease in the aperture ratio due to the formation of the subpattern, the lower the total opening ratio due to all the patterns except the subpatterns between the plurality of the virtual regions with respect to the first photomask. It is characterized by.

Moreover, the design method of the 1st photomask which concerns on this invention is a method which forms the main pattern to be transferred to the photosensitive member, and designs the photomask used for manufacture of a semiconductor device. In this design method, the main pattern is first determined based on the circuit configuration of the semiconductor device. Next, at least the irradiation area to which the exposure light is to be irradiated is divided into a plurality of virtual areas of any predetermined shape, and the total opening ratio due to the pattern determined at that time for each virtual area is obtained. Thereafter, the transfer to the photosensitive member determines any plurality of subpatterns. In the step of determining the plurality of subpatterns, the aperture ratio is substantially constant between the plurality of virtual regions.

In the method of designing the second photomask according to the present invention, in the step of determining the plurality of subpatterns with respect to the design method of the first photomask, the aperture ratio according to the formation of the subpattern is formed in a virtual region having a lower total opening ratio. It is characterized by reducing the fall amount.

According to these various aspects of the present invention, the influence of the local flare becomes substantially uniform over the entire photomask, so that variations in line width in the pattern transferred to the photosensitive member are also uniform. Such uniform variation in size can be easily corrected, for example, by adjusting the output energy of the exposure machine, so that it is possible to easily transfer a desired pattern to the photosensitive member.

Basic gist of the present invention

First, the basic bone of the present invention will be described with reference to the accompanying drawings. 1 is a schematic diagram showing the positional relationship between the regions A to C on the photomask.

In FIG. 1, the arbitrary area | region A and the arbitrary area | regions B and C shall be spaced apart in the range of about 20 micrometers. When the light is irradiated on such a photomask, a flare for generating light passing through the regions B and C transfers a pattern formed in the region A to affect a pattern formed on a photosensitive member (transfer material) such as a photosensitive resist. Crazy As a result, when the line pattern is formed in the area A, the line width fluctuates.

Here, the relationship between the distance between the pattern affected by the local flare and the pattern affected and the degree of influence of the local flare will be described. The present inventor relates to the above relationship by the following method, and found that the shorter the distance between the two patterns, the greater the degree of local flare. 2A to 2C are schematic views showing a method of quantifying a local flare, and Fig. 3 is a graph obtained by the method shown in Figs. 2A to 2C. In addition, in FIG.2A-2C, the apply | coated area | region shows the light shielding area and the other area | region shows the transmission area | region. The same applies to drawings showing other mask patterns.

In this method, first, a transmission line pattern having a width shown in Fig. 2A having a width of 0.12 mu m was referred to as a reference, and this reference was transferred to measure the line width of the pattern formed on the photosensitive member. Subsequently, as shown in FIG. 2B, exposure was performed using the mask in which the ring-shaped transmission pattern was formed around the reference, and the line width of the line pattern formed on the photosensitive member was measured. The inner diameter of the circle at this time is 4.14 mu m, and the width of the circle is 2.76 mu m. Subsequently, as shown in Fig. 2C, the line width was measured by changing the inner diameter of the ring-shaped transmission pattern while keeping the width of the circle constant. The inner diameter of the circle at this time is 6.89 m, and the width of the circle is 2.76 m. Then, the line width was measured by changing the inner diameter of a ring-shaped transmission pattern, making the width of a circle constant. And the variation amount of each line width with respect to the line width of the line pattern formed by exposure using the mask in which only the reference was formed was plotted. 3 shows this result.

In exposure, the scanner type exposure machine using the ArF excimer laser light source was used, and illumination conditions were set to aperture ratio (NA) = 0.80 and 1/2 ring (sigmaout = 0.85).

As a result of the above quantification, as shown in Fig. 3, a significant increase in the line width occurred in the range of the inner diameter of about 15 mu m or less. This indicates that the reference is greatly influenced by local flares from the pattern spaced about 15 mu m. In addition, the closer the pattern is to the reference, the greater the influence of the local flare.

Therefore, in the present invention, when the irradiation area to which at least the exposure light is to be irradiated from the photomask is divided into a plurality of virtual areas having a certain shape, the aperture ratio is substantially constant between these virtual areas. Here, it is preferable that the "opening ratio is substantially constant" is that the aperture ratio is completely constant. However, even if a constraint subpattern of the photomask design is formed, the aperture ratio may not be completely constant. It also means to be included. For example, the subpattern may be formed in the photomask in addition to the main pattern so that the amount of decrease in the aperture ratio due to the formation of the subpattern is lower in the virtual region having a lower total opening rate by all patterns except the subpattern.

For example, when the irradiation area 1 of the photomask is partitioned into a square virtual area having a side length of 2 μm as shown in FIG. 4, the virtual area 2 and the virtual area 3 in FIG. In the case where the total opening ratio by all patterns except the subpattern of the virtual region 2 is lower than that of the virtual region 3, the decrease in the aperture ratio due to the formation of the subpattern in the virtual region 2 is reduced to the virtual region 3. It is higher than the fall amount of aperture ratio by forming the subpattern in (). On the contrary, when the total opening ratio by all patterns except the subpattern of the virtual region 3 is lower than that of the virtual region 2, the decrease in the aperture ratio due to the formation of the subpattern in the virtual region 2 is determined by the virtual region ( It is lower than the fall amount of the aperture ratio by forming the subpattern in 3). In addition, although not shown in FIG. 4, the amount of decrease in the aperture ratio due to the formation of the subpattern is set as described above for the other full-virtual regions of the irradiation region 1. Especially preferably, the aperture ratio of the full-virtual region in the irradiation region 1 is constant.

Here, the "decrease in opening ratio" is not an absolute value, and a negative value is employed when the aperture ratio increases as the subpattern is formed. And the negative value is compared as it is, using the negative value as it is.

Specific Embodiments of the Invention

Next, specific embodiments of the present invention will be described with reference to the accompanying drawings.

(1st embodiment)

First, the first embodiment of the present invention will be described. 5A to 5D are schematic diagrams showing a photomask according to the first embodiment of the present invention. FIG. 5A shows the main pattern of the virtual region 2 in FIG. 4, and FIG. 5B shows the main pattern of the virtual region 3 in FIG. 5C shows a main pattern and a subpattern (dummy pattern) of the virtual region 2, and FIG. 5D shows a main pattern and a subpattern (dummy pattern) of the virtual region 3. These main patterns and subpatterns are light shielding patterns.

In the present embodiment, as shown in Figs. 5A and 5B, the aperture ratios when only the main patterns of the virtual regions 2 and 3 are formed are 60% and 90%, respectively. Conventional photomasks are used in this state. In contrast, in this embodiment, as shown in Figs. 5C and 5D, dummy patterns are formed in the virtual regions 2 and 3 as subpatterns. The dummy pattern in the virtual region 2 is a square shading pattern having a side length of 0.15 μm, and the dummy pattern in the virtual region 3 is a square shading pattern having a side length of 0.2 μm. The pitch (center distance) of these dummy patterns is uniform between the virtual regions 2 and 3. The aperture ratios of the virtual regions 2 and 3 are all set to 30%.

Although not shown in Figs. 5A to 5D, dummy patterns of appropriate sizes are formed at the same pitch in all other virtual regions, and the aperture ratio of each virtual region is set to 30%.

Table 1 summarizes the "total opening ratio by all patterns except the subpattern" and "the amount of decrease of the aperture ratio by forming a subpattern" in each virtual area.

Here, the position where the dummy pattern is formed is a position that does not affect the operation of the semiconductor device beyond the allowable range even when transferred to the photosensitive member. That is, the dummy pattern is formed outside the so-called design data prohibited area (design data prohibited frame). Therefore, the dummy pattern is not formed at a position that causes a short circuit of the wiring or a significant increase in the parasitic capacitance.

When exposure using the photomask which concerns on such a 1st embodiment comprised in this way is performed, the quantity of the light which arose by the local flare will become substantially uniform in any point within the range to which the exposure light of a photosensitive member is irradiated. As a result, even if the line width fluctuates, the degree becomes uniform throughout the photomask.

In addition, in the first embodiment, the pitch between the dummy patterns is made constant to adjust the size of the dummy pattern. However, the aperture ratio is made uniform between the virtual regions by making the size of the dummy pattern constant and adjusting the pitch between the dummy patterns. You may also In other words, the lower the opening ratio of the main pattern, the coarser the subpattern. In addition, you may make an aperture ratio uniform between virtual areas by adjusting both a pitch and a magnitude | size. That is, the lower the opening ratio by the main pattern, the smaller the size of the subpattern, and the subpattern may be coarsely formed.

(2nd embodiment)

Next, a second embodiment of the present invention will be described. 6A to 6D are schematic diagrams showing a photomask according to a second embodiment of the present invention. FIG. 6A shows the main pattern of the virtual region 2 in FIG. 4, and FIG. 6B shows the main pattern of the virtual region 3 in FIG. 4. 6C shows a main pattern and a subpattern (dummy pattern) of the virtual region 2, and FIG. 6D shows a main pattern and a subpattern (dummy pattern) of the virtual region 3. These main patterns and subpatterns are light shielding patterns.

Also in the present embodiment, as shown in Figs. 6A and 6B, the aperture ratios when only the main patterns of the virtual regions 2 and 3 are formed are 60% and 90%, respectively. In the present embodiment, as shown in Figs. 6C and 6D, dummy patterns are formed in the virtual regions 2 and 3 as subpatterns. The dummy pattern in the virtual region 2 is a rectangular shading pattern having a side length of 0.05 µm, and the dummy pattern in the virtual region 3 is a square shading pattern having a side length of 0.08 µm. The size of these patterns is below the resolution limit and is not transferred to the photosensitive member by exposure. The pitch (center distance) of these dummy patterns is uniform between the virtual regions 2 and 3. The aperture ratios of the virtual regions 2 and 3 are all set to 30%.

In addition, although not shown in Figs. 6A to 6D, also in all other virtual regions, dummy patterns having an appropriate size below the resolution limit are formed at the same pitch as the dummy patterns in the virtual regions 2 and 3, The aperture ratio is set to 30%.

Table 2 shows adjustment of the "total opening ratio according to all patterns except the subpattern" and "the amount of reduction of the aperture ratio when the subpattern is formed" in each virtual region.

Even if exposure using the photomask according to the second embodiment configured as described above is performed, the amount of light generated by the local flare becomes substantially uniform at any point within the range where the exposure light of the photoconductor is irradiated. As a result, even if the line width fluctuates, the degree becomes uniform throughout the photomask.

In addition, in the second embodiment, since the dummy pattern is smaller than the minimum size to be transferred, it is possible to form the dummy pattern at a position where the pattern should not be formed on the photoconductor unlike the first embodiment.

In addition, also in the second embodiment, although the pitch between the dummy patterns is made constant to adjust the size of the dummy pattern, the aperture ratio is uniformed between the virtual regions by making the size of the dummy pattern constant and adjusting the pitch between the dummy patterns. You may let it. That is, the lower the opening ratio by the main pattern, the coarser the subpattern may be formed. Moreover, you may make an aperture ratio uniform among virtual areas by adjusting both a pitch and a magnitude | size. In other words, as the aperture ratio according to the main pattern is lowered, the size of the subpattern may be reduced, and the subpattern may be coarsely formed.

(Third embodiment)

Next, a third embodiment of the present invention will be described. 7A to 7D are schematic diagrams showing a photomask according to a third embodiment of the present invention. FIG. 7A shows the main pattern and the polishing countermeasure pattern of the virtual region 2 in FIG. 4, and FIG. 7B shows the main pattern and the polishing countermeasure pattern of the virtual region 3 in FIG. 4. 7C shows the main pattern, the polishing countermeasure pattern and the subpattern (dummy pattern) of the virtual region 2, and FIG. 7D shows the main pattern, the polishing countermeasure pattern and the subpattern (dummy pattern) of the virtual region 3. ). These main patterns, the polishing measures pattern, and the subpatterns are light shielding patterns.

Here, the pattern for grinding | polishing measures is demonstrated. The polishing countermeasure pattern is conventionally formed in an appropriate photomask. In the manufacture of a semiconductor device, after etching a wiring layer, an insulating layer or the like on a semiconductor substrate using a photosensitive resist having a pattern as a mask, another material is embedded in a groove or the like formed by the etching, and then CMP (chemical Mechanical polishing). At this time, when the density difference of the layer etched in the wafer is large, the polishing amount may vary greatly depending on this difference. For this reason, in order to make the density difference of the etched layer small, the pattern for grinding | polishing measures may be formed in a photomask with moderate density.

In the present embodiment, as shown in Figs. 7A and 7B, the aperture ratio in the case where the main pattern and the polishing countermeasure pattern are formed in both of the virtual regions 2 and 3, and only these are formed, 30% and 50%, respectively. In this embodiment, as shown in FIG. 7D, a dummy pattern is formed in the virtual region 3 as a subpattern. The dummy pattern is a square light shielding pattern having a side length of 0.08 μm. The size of this dummy pattern is below the resolution limit and is not transferred to the photosensitive member by exposure. And the opening ratio of the virtual region 3 is set to 30%. On the other hand, as shown in Fig. 7C, the dummy pattern is not formed in the virtual region 2, and the aperture ratio is 30%.

Although not shown in Figs. 7A to 7D, also in all other virtual regions, when the opening ratio exceeds 30% in the state where only the main pattern and the polishing countermeasure pattern are formed, a dummy pattern of an appropriate size below the resolution limit is formed. It is formed and the aperture ratio of each virtual region is set to 30%.

Table 3 summarizes the "total opening ratio by all patterns except a subpattern" and "the amount of reduction of the aperture ratio by forming a subpattern" in each virtual area.

Even if exposure using the photomask which concerns on 3rd embodiment comprised in this way is performed, the quantity of the light which arose by the local flare will become substantially uniform in any point within the range to which the exposure light of a photosensitive member is irradiated. As a result, even if the line width fluctuates, the degree becomes uniform throughout the photomask.

Moreover, also in 3rd Embodiment, since each dummy pattern is smaller than the minimum magnitude | size which is transcribe | transferred, it is possible to form a dummy pattern also in the position where a pattern should not be formed in a photosensitive member.

(4th embodiment)

Next, a fourth embodiment of the present invention will be described. 8A to 8D are schematic diagrams showing a photomask according to a fourth embodiment of the present invention. FIG. 8A shows the main pattern and the polishing countermeasure pattern of the virtual region 2 in FIG. 4, and FIG. 8B shows the main pattern and the polishing countermeasure pattern of the virtual region 3 in FIG. 4. 8C shows the main pattern, the polishing countermeasure pattern and the subpattern (dummy pattern) of the virtual region 2, and FIG. 8D shows the main pattern, the polishing countermeasure pattern and the subpattern (dummy pattern) of the virtual region 3. ). These main patterns and the polishing measures pattern are light shielding patterns. On the other hand, the subpattern includes not only a light shielding pattern but also a transmission pattern as described later.

In the present embodiment, as shown in Figs. 8A and 8B, the opening ratios in the case where the main pattern and the polishing countermeasure pattern are formed in both of the virtual regions 2 and 3, and only these are formed are 20, respectively. %, 50%. In this embodiment, as shown in Fig. 8C, a dummy pattern made of a transmission pattern is formed in the virtual region 2 as a subpattern. The dummy pattern in the virtual region 2 is smaller than the resolution limit and is formed as a hole pattern in the polishing countermeasure pattern. As shown in Fig. 8D, a dummy pattern is formed in the virtual region 3 as a subpattern. Each dummy pattern in the virtual region 3 is a square light shielding pattern having a side length of 0.08 μm. The size of these dummy patterns is below the resolution limit and is not transferred to the photosensitive member by exposure. The aperture ratios of the virtual regions 2 and 3 are set to 30%.

In addition, although not shown in Figs. 8A to 8D, in all other virtual regions, when the aperture ratio exceeds 30% in the state where only the main pattern and the polishing countermeasure pattern are formed, the light-shielding pattern with the appropriate size below the resolution limit is used. When the dummy pattern is formed and the aperture ratio is less than 20% in the state where only the main pattern and the polishing countermeasure pattern are formed, a dummy pattern made of a transmission pattern having an appropriate size below the resolution limit is formed in the polishing countermeasure pattern. And all the aperture ratios of each virtual area are set to 30%.

Table 4 summarizes the "total opening ratio by all patterns except the subpattern" and "the amount of decrease of the aperture ratio by forming a subpattern" in each virtual area.

Even if exposure using the photomask according to the fourth embodiment configured as described above is performed, the amount of light generated by the local flare is substantially uniform at any point within the range where the exposure light of the photoconductor is irradiated. As a result, even if the line width fluctuates, the degree becomes uniform throughout the photomask.

According to these embodiments, the variation in the line width due to the influence of the local flare becomes uniform throughout the photomask. The increase or decrease in the line width can be easily performed by, for example, adjusting the output energy of the exposure machine. Therefore, it is possible to easily obtain a resist pattern having a desired line width without requiring modification of a complicated photomask pattern.

In addition, in these embodiments, although the aperture ratio is constant between all the virtual areas, this invention is not limited to this. That is, even if the aperture ratio is not constant, the amount of decrease in the aperture ratio due to the formation of the subpattern may be lowered in the virtual region having a lower total opening rate by all patterns except the subpattern.

In addition, the upper limit of the size of the virtual region may be determined based on the extent of the influence of the local flare and the degree of the influence. For example, when the graph shown in FIG. 3 can be obtained, it can be considered that the range of the influence of the local flare is within a circle having a radius of about 20 µm. On the other hand, with respect to the lower limit of the size of the virtual region, theoretically, the smaller the virtual region becomes, the more uniform the effect of the local flare is. However, if the virtual region is too small, there is a possibility that a subpattern is formed because a main pattern exists on the entire surface thereof. It may disappear. Also, the smaller the virtual region, the greater the load on the calculator. Therefore, under the existing design rules, the shape of the virtual region is preferably a rectangle whose length is about 0.5 µm to 5 µm, and more preferably a rectangular area whose length is about 2 µm to 5 µm.

In the first to fourth embodiments, the main pattern (and the polishing countermeasure pattern) is formed as the light shielding pattern, but the present invention can also be applied to a photomask formed as a transmission pattern. 9A to 9D are schematic diagrams showing a photomask in which the positive type / negative type is inverted with respect to the first embodiment. Even in such a case, the subpattern is formed such that the amount of decrease in the aperture ratio due to the formation of the subpattern is lower in the virtual region having a lower total opening rate by all patterns except the subpattern.

Table 5 summarizes the "total opening ratio by all patterns except the subpattern" and "the amount of decrease of the aperture ratio by forming a subpattern" in each virtual area.

As shown in Table 5, in the example shown in Figs. 9A to 9D, the total opening ratio (10%) by all patterns except the subpattern of the virtual region 3 is lower than that of the virtual region 2 (40%). Therefore, the fall amount (-60%) of the aperture ratio as the subpattern of the virtual region 3 is formed is lower than that of the virtual region 2 (-30%).

Next, when designing the photomask as described above, the main pattern is first determined based on the circuit configuration. At this time, like the third embodiment and the fourth embodiment, the polishing countermeasure pattern may be designed together. Subsequently, the entire irradiation area is divided into virtual areas, and the total opening rate by the main pattern (and polishing countermeasure pattern), that is, the total opening rate by all patterns except the subpattern, is obtained for each virtual area. Next, in the virtual region where the total opening ratio by all patterns except the subpattern is lower, the amount of decrease in the aperture ratio due to the formation of the subpattern is lowered, so that the shape (size) and the position (pitch) of the subpattern in the photomask as described above. Is determined. At this time, a subpattern to be transferred to the photosensitive member may be formed as in the first embodiment, or a subpattern not to be transferred to the photosensitive member may be formed as in the second embodiment. In addition, as in the fourth embodiment, a subpattern may be formed in the polishing countermeasure pattern. In this way, the pattern of each virtual area is designed, and the design of the whole photomask is completed.

In addition, when manufacturing a semiconductor device using a photomask as mentioned above, the photosensitive resist is first formed on a to-be-processed layer by application | coating etc., and this photosensitive resist is exposed using a photomask. Thereafter, the photosensitive resist may be developed, and the processed layer may be processed using the patterned photosensitive resist as a mask.

As described above in detail, according to the present invention, the amount of light generated by the local flare can be made substantially uniform at any point within the range where the exposure light of the photoconductor is irradiated. For this reason, even if the fluctuation | variation of a line width generate | occur | produces, the grade becomes uniform throughout the photomask. In addition, the increase and decrease of the line width can be easily performed by, for example, adjusting the output energy of the exposure machine. Therefore, a resist pattern having a desired line width can be easily obtained without requiring modification of a complicated photomask pattern.

Virtual Zone (2) Virtual Zone (3) Total opening rate by all patterns except subpattern 60% 90% Amount of decrease in aperture ratio as the subpattern is formed 30% 60%

Virtual Zone (2) Virtual Zone (3) Total opening rate by all patterns except subpattern 60% 90% Amount of decrease in aperture ratio as the subpattern is formed 30% 60%

Virtual Zone (2) Virtual Zone (3) Total opening rate by all patterns except subpattern 30% 50% Amount of decrease in aperture ratio as the subpattern is formed 0 % 20%

Virtual Zone (2) Virtual Zone (3) Total opening rate by all patterns except subpattern 20% 50% Amount of decrease in aperture ratio as the subpattern is formed -10% 20%

Virtual Zone (2) Virtual Zone (3) Total opening rate by all patterns except subpattern 40% 10% Amount of decrease in aperture ratio as the subpattern is formed -30% -60%

Claims (38)

In the photomask to be formed on the photoconductor, a main pattern to be transferred and used for manufacturing a semiconductor device, A plurality of subpatterns are formed at random, whether or not transfer to the photosensitive member is possible, An aperture ratio is substantially constant between the plurality of virtual regions when at least the irradiation region to which the exposure light is to be irradiated is divided into a plurality of virtual regions having a certain shape. In the photomask to be formed on the photoconductor, a main pattern to be transferred and used for manufacturing a semiconductor device, A plurality of subpatterns are formed at random, whether or not transfer to the photosensitive member is possible, When at least the irradiation area to which the exposure light is to be irradiated is divided into a plurality of virtual regions having a certain shape, the sub-pattern becomes more virtual among the plurality of virtual regions with a lower total opening ratio by all patterns except the sub-patterns. A photomask, characterized in that the amount of decrease in the aperture ratio as formed. The photomask according to claim 1, wherein the subpattern is formed at a position where an influence on the operation of the semiconductor device when the subpattern is transferred to the photosensitive member is within an allowable range. The photomask according to claim 2, wherein the subpattern is formed at a position where an influence on the operation of the semiconductor device when the subpattern is transferred to the photosensitive member is within an acceptable range. The method of claim 1, wherein between the plurality of virtual regions, The pitch of the subpattern is substantially constant, A photomask, characterized in that the size of the subpattern is smaller as a virtual area having a lower total opening rate by all patterns except the subpattern. The method of claim 2, wherein between the plurality of virtual regions, The pitch of the subpattern is substantially constant, A photomask, characterized in that the size of the subpattern is smaller as a virtual area having a lower total opening rate by all patterns except the subpattern. The method of claim 1, wherein between the plurality of virtual regions, The size of the subpattern is substantially constant, A photomask in which the subpattern is formed more coarse in a virtual region having a lower total opening rate by all patterns except for the subpattern. The method of claim 2, wherein between the plurality of virtual regions, The size of the subpattern is substantially constant, A photomask in which the subpattern is formed more coarse in a virtual region having a lower total opening rate by all patterns except for the subpattern. The method of claim 1, wherein the subpattern is smaller in size and the subpattern is formed coarser in the virtual region having a lower total opening ratio due to all patterns except the subpatterns between the plurality of virtual regions. Photomask. 3. The method of claim 2, wherein the subpattern is smaller in size and the subpattern is coarser in the virtual region having a lower total opening ratio due to all patterns except the subpatterns between the plurality of virtual regions. Photomask. The photomask of claim 1, wherein the virtual region is a rectangular region having a length of 0.5 μm to 5 μm in each side. The photomask of claim 2, wherein the virtual region is a rectangular region having a length of 0.5 μm to 5 μm in each side. The photomask of claim 1, wherein a size of the subpattern is smaller than a minimum size transferred to the photosensitive member by exposure. The photomask according to claim 2, wherein a size of the subpattern is smaller than a minimum size transferred to the photosensitive member by exposure. The pattern for polishing countermeasures according to claim 1, wherein the pattern for polishing countermeasures having a size equal to or greater than the minimum size transferred to the photosensitive member by exposure, and in which the influence on the operation of the semiconductor device when it is transferred to the photosensitive member is within an acceptable range. Photomask, characterized in that. The pattern for polishing countermeasures according to claim 2, wherein the pattern for polishing countermeasures having a size equal to or greater than the minimum size transferred to the photosensitive member by exposure and in which the influence on the operation of the semiconductor device when it is transferred to the photosensitive member is within an acceptable range is formed. Photomask, characterized in that. The positive type / negative type is different between the subpattern and the polishing countermeasure pattern. The subpattern is formed inside the pattern for polishing measures. The positive type / negative type is different between the subpattern and the polishing countermeasure pattern. The subpattern is formed inside the pattern for polishing measures. In the method for forming a photomask to be formed in the photosensitive member to be transferred to the main pattern and to manufacture a semiconductor device, Determining a main pattern based on a circuit configuration of the semiconductor device; Dividing at least the irradiation area to which the exposure light is to be irradiated into a plurality of virtual areas having an arbitrary shape, and calculating the total opening ratio by the pattern determined at that time for each virtual area; Transfer to the photosensitive member has a step of determining any plurality of subpatterns, The step of determining the plurality of subpatterns, wherein the aperture ratio is made substantially constant between the plurality of virtual regions. In the method for forming a photomask to be formed in the photosensitive member to be transferred to the main pattern and to manufacture a semiconductor device, Determining a main pattern based on a circuit configuration of the semiconductor device; Dividing at least the irradiation area to which the exposure light is to be irradiated into a plurality of virtual areas having an arbitrary shape, and calculating the total opening ratio by the pattern determined at that time for each virtual area; Transfer to the photosensitive member has a step of determining any plurality of subpatterns, The determining method of the plurality of subpatterns, wherein the lowering of the aperture ratio as the subpattern is formed is lower in the virtual region having a lower total opening ratio. 20. The method according to claim 19, wherein in the step of determining the plurality of subpatterns, the plurality of subpatterns are arranged at positions within which an influence on the operation of the semiconductor device when it is transferred to the photosensitive member is within an acceptable range. A design method of a photomask, characterized in that. 21. The method of claim 20, wherein in the step of determining the plurality of subpatterns, the plurality of subpatterns are disposed at positions where an influence on the operation of the semiconductor device when the photoresist is itself transferred is within an acceptable range. A design method of a photomask, characterized in that. 20. The method of claim 19, wherein in the step of determining the plurality of subpatterns, the pitch of the subpatterns is substantially constant between the plurality of virtual regions, and the total opening ratio of all patterns except the subpatterns is low. The method of designing a photomask, characterized in that the size of the subpattern is smaller as the virtual area. 21. The method of claim 20, wherein in the step of determining the plurality of subpatterns, the pitch of the subpatterns is substantially constant between the plurality of virtual regions, and the total opening ratio of all patterns except the subpatterns is low. The method of designing a photomask, characterized in that the size of the subpattern is smaller as the virtual area. 20. The method of claim 19, wherein in the step of determining the plurality of subpatterns, the size of the subpattern is substantially constant between the plurality of virtual regions, and the total opening ratio of all patterns except the subpatterns is low. The submask pattern is arranged more coarsely in the virtual region. 21. The method of claim 20, wherein in the step of determining the plurality of subpatterns, the size of the subpattern is substantially constant between the plurality of virtual regions, and the total opening ratio of all patterns except the subpatterns is low. The submask pattern is arranged more coarsely in the virtual region. 20. The method of claim 19, wherein in the step of determining the plurality of subpatterns, the size of the subpattern is reduced while the virtual region having a low total opening ratio by all patterns except the subpatterns is used. A method of designing a photomask, characterized in that the arrangement. 21. The method of claim 20, wherein in the step of determining the plurality of subpatterns, the size of the subpattern is reduced while the virtual region having a low total opening ratio by all patterns except the subpatterns is used. A method of designing a photomask, characterized in that the arrangement. The method of designing a photomask according to claim 19, wherein in the step of determining the plurality of subpatterns, the virtual area is a rectangular area having a length of 0.5 µm to 5 µm in each side. 21. The method of claim 20, wherein in the step of determining the plurality of subpatterns, the virtual region is a rectangular region having a length of 0.5 µm to 5 µm for each side. The method of designing a photomask according to claim 19, wherein in the step of determining the plurality of subpatterns, the size of the subpattern is made smaller than the minimum size transferred to the photosensitive member by exposure. 21. The method of claim 20, wherein in the step of determining the plurality of subpatterns, the size of the subpattern is made smaller than the minimum size transferred to the photosensitive member by exposure. The method according to claim 19, wherein before the step of obtaining the total opening ratio, And having a step of determining a pattern for polishing countermeasures having a size equal to or greater than the minimum size to be transferred to the photosensitive member by exposure and having an influence on the operation of the semiconductor device when it is transferred to the photosensitive member is within an acceptable range. How to design a photomask. The method according to claim 20, wherein before the step of obtaining the total opening ratio, And a step of determining a pattern for polishing countermeasures having a size equal to or greater than the minimum size transferred to the photosensitive member by exposure and whose influence on the operation of the semiconductor device when it is transferred to the photosensitive member is within an acceptable range. How to design a photomask. The method of claim 33, wherein in the determining of the plurality of subpatterns, The positive type / negative type is different between the subpattern and the polishing countermeasure pattern, And the subpattern is disposed inside the polishing countermeasure pattern. 35. The method of claim 34, wherein in the determining of the plurality of subpatterns, The positive type / negative type is different between the subpattern and the polishing countermeasure pattern, And the subpattern is disposed inside the polishing countermeasure pattern. A method of manufacturing a semiconductor device, comprising the step of exposing a photosensitive member formed on a layer to be processed using the photomask according to claim 1. The process of exposing the photosensitive member formed on the to-be-processed layer using the photomask of Claim 2, The manufacturing method of the semiconductor device characterized by the above-mentioned.