JP2005039151A - Complementary stencil masks, method of fabricating the same, and method of forming pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent localized stress concentration in complementary stencil masks and to prevent pattern transfer defects from occurring in overlay exposure using the complementary masks. <P>SOLUTION: A prescribed pattern 100 to be transferred is divided into a first pattern 110 composed of parts where square-shaped patterns obtained by dividing the pattern 100 cross each other and a second pattern 120 composed of linearly shaped remainder obtained by subtracting the first pattern 110 from the prescribed pattern 100. The first and second patterns are arranged in respective complementary masks. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electron beam lithography technique in semiconductor device processing.

  In recent years, along with the high integration of semiconductor integrated circuits, miniaturization of circuit patterns has also progressed, so that improvement in resolution in lithography is required. For example, according to a transfer exposure technique using an electron beam, a pattern having a dimension of 50 nm or less can be formed.

  As a transfer exposure technique using an electron beam, there are a method of partially transferring a circuit pattern at a reduced size, a method of transferring a circuit pattern at an equal magnification, and the like. For example, in the reduction transfer method disclosed in Non-Patent Document 1, an electron beam is irradiated to a stencil mask provided with an opening corresponding to a circuit pattern to be transferred, and the electron beam passing through the opening of the stencil mask is The image is reduced and transferred onto the wafer by the reduction projection optical system.

  For example, when the circuit pattern 10 shown in FIG. 14A is transferred, reduction transfer can be performed using the stencil mask 20 shown in FIG. Here, the stencil mask 20 includes a mask substrate portion 21 and an opening portion 22 provided in the mask substrate portion 21 so as to correspond to the circuit pattern 10. However, as shown in FIG. 14B, when the stencil mask 20 has a mask structure in which the large leaf structure portion 23 is supported by the thin support portion 24, stress is applied to the support portion 24 due to the weight of the leaf structure portion 23. Therefore, the mechanical strength of the support portion 24 is weakened. As a result, long-term use of such a mask can cause mask deformation or mask destruction.

  Therefore, as disclosed in Patent Document 1, for example, a complementary mask has been proposed in which a circuit pattern is divided into two stencil masks so that excessive stress is not applied to the stencil mask. For example, when the circuit pattern 30 shown in FIG. 15A is transferred, the circuit pattern 30 shown in FIG. 15A is changed into the first pattern 31 shown in FIG. 15B and FIG. 15C. And the divided patterns 31 and 32 are divided into a first complementary mask 40 shown in FIG. 15 (d) and a second complementary mask 50 shown in FIG. 15 (e), respectively. And sort. Here, the first complementary mask 40 includes a mask substrate 41 and an opening 42 provided in the mask substrate 41 so as to correspond to the first pattern 31. The second complementary mask 50 includes a mask substrate portion 51 and an opening 52 provided in the mask substrate portion 51 so as to correspond to the second pattern 32.

When performing transfer exposure on a wafer using a set of complementary masks 40 and 50, first, first transfer exposure with an electron beam is performed using the first complementary mask 40, and then the first transfer is performed. A second transfer exposure using an electron beam is performed using the second complementary mask 50 in accordance with the position where the exposure has been performed. Thereby, a desired circuit pattern image shown in FIG. 15A can be transferred. Further, as shown in FIGS. 15D and 15E, the circuit pattern is divided and disposed on the two stencil masks 40 and 50, so that no excessive stress is locally applied to each mask. Therefore, it is possible to prevent the mask from being deformed or broken.
Kazuaki Suzuki, Tomoharu Fujiwara, Kazunari Hada, Noriyuki Hirayanagi, Shintaro Kawata, Kenji Morita, Kazuya Okamoto, Teruaki Okino, Sumito Shimizu, Takehisa Yahiro, "Nikon EB stepper: its system concept and counter measures for critical issues", Proceeding of SPIE, United States, 2000, Volume 3997, p.214-224 JP 2002-260992 A

  However, in the conventional transfer exposure method using an electron beam using a complementary stencil mask, when an overlay error occurs when performing overlay exposure using the first complementary mask and the second complementary mask, a pattern is formed. Serious defects can occur that will not resolve.

  Hereinafter, in order to transfer the circuit pattern 30 shown in FIG. 15A, the first complementary mask 40 shown in FIG. 15D and the second complementary mask 50 shown in FIG. A case where alignment exposure is performed will be described as an example. First, exposure is performed using the first complementary mask 40 to obtain a first transfer image 61 as shown in FIG. Next, exposure is performed in accordance with the position of the first transfer image 61 using the second complementary mask 50, thereby obtaining a second transfer image 62 as shown in FIG. At this time, if an error occurs when positioning with respect to the first transfer image 61, the final transfer image (second transfer image 62) is shifted from the ideal transfer image 63. As a result, a close proximity portion 64 in which the first transfer image 61 and the second transfer image 62 are abnormally close to each other is generated. Even if the final transfer image position accuracy is within the allowable range, if such a close proximity portion 64 occurs, the image contrast of that portion deteriorates, and in the worst case, the resist is developed. After that, there is a risk that the part will not be separated and resolved.

  In view of the above, the present invention makes it possible to prevent local stress concentration in a complementary stencil mask used in an electron beam exposure method, and to perform pattern transfer when performing overlay exposure using the complementary mask. The object is to prevent the occurrence of defects.

  In order to achieve the above object, a first complementary stencil mask manufacturing method according to the present invention is a method for generating a set of complementary stencil masks for transferring a predetermined pattern. Dividing the pattern into a plurality of square patterns, extracting a pattern intersection that is an adjacent portion of the square patterns, creating a first pattern composed of the extracted pattern intersections, and a predetermined pattern Creating a second pattern by subtracting the first pattern, providing a first opening corresponding to the first pattern in the first mask constituting a set of complementary stencil masks; Providing a second opening corresponding to the second pattern in the second mask constituting the set of complementary stencil masks.

  According to the first complementary stencil mask creation method, a predetermined pattern to be transferred is divided into a first pattern composed of a portion where square patterns intersect with each other, and a remaining pattern obtained by subtracting the first pattern from the predetermined pattern. The pattern is divided into a linear second pattern and arranged on each complementary mask. For this reason, the complicated polygonal pattern that causes local stress concentration in the stencil mask can be divided and placed on each complementary mask, so that no excessive stress is locally applied to each mask. It can be prevented from being deformed or broken. Further, since the linear pattern as the second pattern is the main part of the predetermined pattern, the resolution of the main part of the pattern caused by the overlay error when overlay exposure is performed using a plurality of complementary masks. Defects, that is, pattern transfer defects can be prevented.

  In the first complementary stencil mask creation method, in the step of creating the first pattern, only pattern intersections having an area smaller than the area of the corresponding rectangular pattern can be extracted from the pattern intersections. preferable. That is, when a minute figure (rectangular pattern) touches a pattern intersection, it is preferable not to extract the intersection, in other words, not to divide the intersection.

  In this way, unnecessary pattern division can be prevented.

  In the first complementary stencil mask creating method, a step of creating a third pattern by extending an end portion of the first pattern in contact with the second pattern in the direction of the second pattern, and a predetermined pattern Forming a fourth pattern by subtracting the third pattern from the second pattern, and in the step of providing the first opening and the second opening, replacing the first pattern with the third pattern, It is preferable that a corresponding first opening is provided in the first mask, and a second opening corresponding to the fourth pattern is provided in the second mask instead of the second pattern.

  In this way, the first pattern, that is, the pattern intersection is expanded to form the third pattern, and the fourth pattern is created by subtracting the third pattern from the predetermined pattern. A sufficient interval between the linear patterns constituting the pattern can be secured. Therefore, in the second mask, the distance between the second openings corresponding to the fourth pattern is widened, so that the mechanical strength of the mask is further increased.

  In this case, the step of forming the fifth pattern by extending the end portion of the third pattern that contacts the fourth pattern in the direction of the fourth pattern, and the third pattern in the fourth pattern, The step of providing the first opening and the second opening is further provided with at least one of the steps of forming the sixth pattern by extending the contacting end in the direction of the third pattern. A step of providing the first mask with a first opening corresponding to the fifth pattern instead of the third pattern, and a second opening corresponding to the sixth pattern instead of the fourth pattern; It is preferable to include at least one of the steps provided for the two masks.

  In this way, when performing overlay exposure using each complementary stencil mask, the extended portion of each pattern acts as a “margin”, thus preventing disconnection at the connection portion between the transfer images of each pattern. be able to. At this time, if the extended width of each of the third pattern and the fourth pattern is equal to or smaller than the predetermined pattern width, the pattern size after transfer becomes substantially uniform at the connection portion, so that a smooth connection portion can be formed. .

  A second complementary stencil mask creation method according to the present invention is a set of complementary stencil mask creation methods for transferring a predetermined pattern, and the predetermined pattern is divided into a plurality of rectangular patterns. A step of extracting a rectangular pattern having a long side extending in a vertical direction from among the plurality of rectangular patterns, creating a first pattern composed of the extracted rectangular patterns, and a long of the plurality of rectangular patterns A step of extracting a rectangular pattern whose sides extend in the horizontal direction, creating a second pattern comprising the extracted rectangular pattern, and a first pattern as a first mask constituting a set of complementary stencil masks And providing a second opening corresponding to the second pattern on the second mask constituting the set of complementary stencil masks. Eteiru.

  According to the second complementary stencil mask creation method, a predetermined pattern to be transferred is divided into a first pattern and a second pattern which are orthogonal to each other and arranged on each complementary mask. For this reason, the complicated polygonal pattern that causes local stress concentration in the stencil mask can be divided and placed on each complementary mask, so that no excessive stress is locally applied to each mask. It can be prevented from being deformed or broken. Further, since the patterns that are close to each other in parallel are arranged in the same complementary mask, when performing overlay exposure using a plurality of complementary masks, poor resolution of the main part of the pattern due to overlay error ( For example, it is possible to prevent a pattern transfer defect).

  Forming a third pattern by extending an end portion of the first pattern in contact with the second pattern in the direction of the second pattern in the second complementary stencil mask producing method; and The method further comprises at least one step of forming a fourth pattern by extending an end portion of the pattern in contact with the first pattern in the direction of the first pattern, the first opening and the second pattern The step of providing the opening corresponds to the step of providing the first opening corresponding to the third pattern instead of the first pattern in the first mask and the fourth pattern instead of the second pattern. It is preferable to include at least one step of providing the second opening in the second mask.

  In this way, when performing overlay exposure using each complementary stencil mask, the extended portion of each pattern acts as a “margin”, thus preventing disconnection at the connection portion between the transfer images of each pattern. be able to. At this time, if the extended width of each of the first pattern and the second pattern is equal to or smaller than the width of the predetermined pattern, the pattern size after transfer is substantially uniform at the connection portion, so that a smooth connection portion can be formed. .

  The first complementary stencil mask according to the present invention is a set of complementary stencil masks for transferring a predetermined pattern, and the first mask constituting the set of complementary stencil masks is a predetermined mask. A second mask having a first opening corresponding to a pattern intersection which is an adjacent portion of a plurality of rectangular patterns obtained by dividing the pattern, and constituting a set of complementary stencil masks, A second opening corresponding to the pattern obtained by subtracting the pattern intersection from the pattern is provided. That is, since the first complementary stencil mask according to the present invention is a complementary stencil mask obtained by the first method according to the present invention, the same effect as that of the method can be obtained.

  The second complementary stencil mask according to the present invention is a set of complementary stencil masks for transferring a predetermined pattern, and the first mask constituting the set of complementary stencil masks is a predetermined mask. A second mask having a first opening corresponding to a rectangular pattern whose long side extends in the vertical direction among a plurality of rectangular patterns formed by dividing the pattern, and constituting a set of complementary stencil masks, The second opening corresponding to the rectangular pattern whose long side extends in the horizontal direction among the plurality of rectangular patterns. That is, since the second complementary stencil mask according to the present invention is a complementary stencil mask obtained by the above-described second method according to the present invention, the same effect as the method can be obtained.

  A first pattern forming method according to the present invention is a pattern forming method using a set of complementary stencil masks for transferring a predetermined pattern, and includes a step of applying a resist film on a substrate, Irradiating the resist film with the first electron beam through the first mask constituting the complementary stencil mask of the second, and second electrons via the second mask constituting the pair of complementary stencil masks A step of irradiating the resist film with a beam; and a step of forming a resist pattern by developing the resist film irradiated with the first electron beam and the second electron beam. The first mask has a first opening corresponding to a pattern intersection which is an adjacent portion of a plurality of rectangular patterns obtained by dividing the pattern, and the second mask is a pattern from a predetermined pattern. Having a second opening corresponding to the pattern obtained by subtracting the difference unit. That is, since the first pattern forming method according to the present invention is a pattern forming method using the mask obtained by the above-described first complementary stencil mask creating method according to the present invention, the same effects as the method are provided. Is obtained. Specifically, since the stencil mask to be used has sufficient mechanical strength, the stencil mask can be used over a long period of time, so that the manufacturing cost can be reduced. Further, since there is no poor resolution of the circuit pattern due to overlay error, pattern transfer can be performed with high accuracy.

  A second pattern forming method according to the present invention is a pattern forming method using a set of complementary stencil masks for transferring a predetermined pattern, the step of applying a resist film on a substrate, Irradiating the resist film with the first electron beam through the first mask constituting the complementary stencil mask of the second, and second electrons via the second mask constituting the pair of complementary stencil masks A step of irradiating the resist film with a beam; and a step of forming a resist pattern by developing the resist film irradiated with the first electron beam and the second electron beam. Of the plurality of rectangular patterns obtained by dividing the pattern, the long side has a first opening corresponding to the rectangular pattern extending in the vertical direction, and the second mask has a plurality of rectangular patterns. The longer sides of having a second opening corresponding to the square shape pattern extending in the horizontal direction. That is, since the second pattern forming method according to the present invention is a pattern forming method using a mask obtained by the above-described second complementary stencil mask creating method according to the present invention, the same effects as the method are provided. Is obtained. Specifically, since the stencil mask to be used has sufficient mechanical strength, the stencil mask can be used over a long period of time, so that the manufacturing cost can be reduced. Further, since there is no poor resolution of the circuit pattern due to overlay error, pattern transfer can be performed with high accuracy.

  In the first or second pattern formation method, the first electron beam blur that passes through the first mask and the second electron beam blur that passes through the second mask are equivalent to each other. It is preferable to further include a beam blur adjusting step for adjusting the current amount of the first electron beam or the second electron beam or the projection optical system of the exposure apparatus.

  In this way, since the blur of the electron beam in each exposure process becomes constant, the shape and dimensions of the pattern formed by the overlay exposure can be made uniform. In this case, if the beam blur adjustment step includes a step of reducing the blur of the first electron beam and the second electron beam to be smaller than the minimum dimension of the predetermined pattern, pattern formation is performed while maintaining a sufficient exposure amount margin. Can be performed.

  According to the present invention, in the production of a complementary stencil mask used in an electron beam exposure method, a complicated pattern is divided and arranged on each complementary mask while the main part of a predetermined pattern to be transferred is not divided as much as possible. Therefore, fine and complicated patterns such as logic gate patterns and multilayer wiring patterns can be transferred to the resist with high accuracy.

(First embodiment)
Hereinafter, a complementary stencil mask and a manufacturing method thereof according to a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a gate pattern to be transferred using the complementary stencil mask of this embodiment. FIGS. 2A to 2E are diagrams for explaining each step of the method for producing a complementary stencil mask of the present embodiment.

  That is, in the method of this embodiment, the transistor gate pattern 100 shown in FIG. 1 is divided and arranged in a set of complementary stencil masks.

  Specifically, first, as shown in FIG. 2A, the gate pattern 100 is divided into a plurality of rectangular patterns (hereinafter referred to as rectangular patterns). This pattern division is basically performed by dividing the gate pattern 100 along the width direction of the gate pattern 100 at the bent portion of the gate pattern 100. In other words, each rectangular pattern has the same width as the gate pattern 100.

  Next, as shown in FIG. 2B, a pattern intersection 101, which is a location where the divided rectangular patterns are adjacent to each other, is extracted. In the present embodiment, the size of the corresponding rectangular pattern in the pattern intersection 101 is comparable or smaller than that of the intersection for the purpose of avoiding as much as possible the portion that does not need to be divided. The intersection 101B is not divided. In other words, only the intersection 101 between large figures (rectangular patterns) is extracted as the intersection 101A to be divided.

  Next, as shown in FIG. 2C, the extended intersection 102 is expanded by extending the end of the intersection 101A to be divided that is in contact with the rectangular pattern (that is, the section of the intersection 101A) in the direction of the rectangle pattern. create. Here, the extended width of the intersecting portion 101A is set to, for example, one half of the line width of the main pattern (rectangular pattern).

  Next, as shown in FIG. 2D, only the extended intersection 102 is extracted, and a first pattern 110 including the extracted extended intersection 102 is created. That is, first pattern data is created.

  Next, as shown in FIG. 2E, a second pattern 120 is created by subtracting the first pattern 110 from the transistor gate pattern 100 shown in FIG. That is, the second pattern data is created by subtracting the first pattern data from the original pattern data.

  Finally, the first and second masks constituting a set of complementary stencil masks are created using each of the first and second pattern data. Specifically, a first opening corresponding to the first pattern 110 is provided in the first mask, and a second opening corresponding to the second pattern 120 is provided in the second mask.

  In the present embodiment, the first pattern 110 shown in FIG. 2D is an intersection of a desired pattern (transistor gate pattern 100), while the second pattern 120 shown in FIG. It consists of a linear pattern that is the main part. Therefore, the original pattern (transistor gate pattern 100) is more accurate when performing overlay exposure using two complementary masks corresponding to the first and second patterns 110 and 120, respectively. Can be restored.

  In this embodiment, as shown in FIGS. 2D and 2E, the original complicated pattern is divided into a first pattern 110 that is an intersection of the patterns and a second pattern that is a simple rectangular pattern. Since it is divided into the pattern 120 and arranged on each complementary mask, sufficient mechanical strength is maintained in each complementary mask. Further, as shown in FIG. 2C, the following effects can be obtained by expanding the intersecting portion 101A by about half the pattern width. That is, when the second pattern 120 is created by subtracting the first pattern 110 composed of the extended intersection 102 from the transistor gate pattern 100, the interval between the linear patterns constituting the second pattern 120 is set. Can take enough. Therefore, in the second mask, the distance between the second openings corresponding to the second pattern 120 is widened, so that the mechanical strength of the mask is further increased.

  As described above, according to the present embodiment, a complicated polygon pattern existing in a predetermined pattern (transistor gate pattern 100) to be transferred can be divided and arranged on each complementary mask. For this reason, local stress concentration in the complementary mask can be prevented, so that the mask can be prevented from being deformed or broken. Furthermore, in order to distribute the main part of the desired pattern (second pattern 120 composed of linear patterns) onto one complementary mask (second mask), overlay exposure is performed using each complementary mask. In this case, it is possible to prevent the resolution failure of the main pattern portion, that is, the pattern transfer defect, caused by the overlay error. That is, the fidelity in the transfer shape of a desired pattern can be improved.

  In the first embodiment, the width for expanding the pattern intersection 101A can be arbitrarily set within a range in which the mechanical strength of the complementary mask is maintained.

  In the first embodiment, the first pattern 110 including the intersecting portion 101A is created without expanding the pattern intersecting portion 101A, and the first pattern 110 is subtracted from the transistor gate pattern 100. Two patterns 120 may be created, and each of the patterns 110 and 120 may be placed on the first and second masks.

  In the first embodiment, after the first and second patterns 110 and 120 are created, the end portion of the first pattern 110 that is in contact with the second pattern 120 (that is, the segment of the first pattern 110) is used. The step of forming the third pattern by extending in the direction of the second pattern 120, and the end of the second pattern 120 in contact with the first pattern 110 (that is, the segment of the second pattern 120) are the first. At least one step of forming the fourth pattern by extending in the direction of the pattern 110 may be further provided. In this case, an opening corresponding to the third pattern may be provided in the first mask instead of the first pattern 110, or an opening corresponding to the fourth pattern instead of the second pattern 120. The portion may be provided on the second mask. In this way, when performing overlay exposure using each complementary stencil mask, the extended portion of each pattern acts as a “margin”, thus preventing disconnection at the connection portion between the transfer images of each pattern. be able to. At this time, if the extended width of each of the first pattern 110 and the second pattern 120 is equal to or smaller than the width of the transistor gate pattern 100, the pattern size after transfer can be made substantially uniform at the connection portion.

  Further, in the first embodiment, the extended intersection 102 is extracted, the first pattern 110 including the extracted extended intersection 102 is created, and the first pattern 110 is subtracted from the gate pattern 100 by subtracting the first pattern 110. Two patterns 120 were created. However, instead of this, the following may be used. That is, first, the intersection 101A is extracted, a first pattern including the extracted intersection 101A is created, and then the second pattern is created by subtracting the first pattern from the gate pattern 100. Then, after creating the third pattern by extending the end of the first pattern (that is, each intersecting portion 101A) in contact with the second pattern (that is, each rectangular pattern) in the direction of the second pattern, the gate A fourth pattern is created by subtracting the third pattern from the pattern 100. Thereafter, an opening corresponding to the third pattern is provided in the first mask instead of the first pattern, and an opening corresponding to the fourth pattern is provided in the second mask instead of the second pattern. . In this case, after creating the third and fourth patterns, the end of the third pattern in contact with the fourth pattern (that is, the segment of the third pattern) is expanded in the direction of the fourth pattern. 5th pattern formation process, and the 6th pattern is formed by extending the edge part (namely, section | slice of 4th pattern) which contact | connects the 3rd pattern in a 4th pattern in the direction of a 3rd pattern. You may further provide at least 1 process of processes. In addition, an opening corresponding to the fifth pattern may be provided in the first mask instead of the third pattern, or an opening corresponding to the sixth pattern may be provided instead of the fourth pattern. It may be provided on the mask. In this way, when performing overlay exposure using each complementary stencil mask, the extended portion of each pattern acts as a “margin”, thus preventing disconnection at the connection portion between the transfer images of each pattern. be able to. At this time, the expansion width of each of the third and fourth patterns is preferably equal to or smaller than the width of the transistor gate pattern 100.

  In the first embodiment, a set of complementary stencil masks for transferring a predetermined pattern is composed of two masks, but a set of complementary stencil masks is composed of three or more masks. Needless to say, the present embodiment can be applied to this case.

  In the first embodiment, the gate pattern is created. However, it goes without saying that the present embodiment can be applied to creation of other patterns.

(Second Embodiment)
Hereinafter, a complementary stencil mask and a method for producing the same according to a second embodiment of the present invention will be described with reference to the drawings.

  FIG. 3 is a diagram showing a gate pattern to be transferred using the complementary stencil mask of this embodiment. FIGS. 4A to 4C are diagrams for explaining each step of the method for producing a complementary stencil mask of the present embodiment.

  That is, in the method of this embodiment, the transistor gate pattern 200 shown in FIG. 3 is divided and arranged in a set of complementary stencil masks. The pattern division is basically performed by dividing the gate pattern 200 along the width direction of the gate pattern 200 at the bent portion of the gate pattern 200. In other words, each rectangular pattern has the same width as the gate pattern 200.

  Specifically, first, as shown in FIG. 4A, the gate pattern 200 is divided into a plurality of rectangular patterns (hereinafter referred to as rectangular patterns).

  Next, as shown in FIG. 4B, a rectangular pattern whose long side extends in the vertical direction is extracted from the plurality of rectangular patterns, and a first pattern 210 including the extracted rectangular patterns is created. That is, first pattern data is created.

  Next, as shown in FIG. 4C, a rectangular pattern having a long side extending in the horizontal direction is extracted from the plurality of rectangular patterns, and a second pattern 220 including the extracted rectangular pattern is created. That is, second pattern data is created.

  In the present embodiment, as shown in FIG. 4B, in the first pattern 210, the end portion (that is, the segment of the first pattern 210) in contact with the rectangular pattern constituting the second pattern 220 is expanded. To do. At this time, the extended width of the first pattern 210 is set to, for example, about one third of the width of the transistor gate pattern 200. Along with this pattern expansion, first pattern data including the expanded portion 211 is newly created.

  Similarly, in the present embodiment, as shown in FIG. 4C, in the second pattern 220, an end portion (that is, a section of the second pattern 220) that is in contact with the rectangular pattern constituting the first pattern 210 is defined. Expand. At this time, the extended width of the second pattern 220 is set to, for example, about one third of the width of the transistor gate pattern 200. Along with this pattern expansion, second pattern data including the expanded portion 221 is newly created.

  Finally, the first and second masks constituting a set of complementary stencil masks are created using each of the first and second pattern data. Specifically, a first opening corresponding to the first pattern 210 (including the extended portion 211) is provided in the first mask, and the second pattern 220 (including the extended portion 221) is provided in the second mask. And a second opening corresponding to.

  In the present embodiment, as shown in FIGS. 4A to 4C, the original pattern (transistor gate pattern 200) having a complicated shape is composed of a first and second pattern 210 including only a simple rectangular pattern, and While being divided into 220, adjacent patterns are arranged in the same mask (see particularly FIG. 4B).

  As described above, according to the present embodiment, complex polygonal patterns existing in a predetermined pattern (transistor gate pattern 200) to be transferred are converted into first and second patterns 210 and 220 that are orthogonal to each other. Divide and place on each complementary mask. For this reason, local stress concentration in the complementary mask can be prevented, so that the mask can be prevented from being deformed or broken. Further, since the patterns that are close to each other in parallel are arranged in the same complementary mask, when performing overlay exposure using a plurality of complementary masks, poor resolution of the main part of the pattern due to overlay error ( For example, it is possible to prevent a pattern transfer defect).

  In addition, according to the present embodiment, after the transistor gate pattern 200 is once divided into the first and second patterns 210 and 220, the sections of each pattern are expanded, and then the openings corresponding to the expanded patterns are formed. Provided on each mask. For this reason, when performing overlay exposure using each complementary stencil mask, the extended portion of each pattern plays the role of “margin”, so that the dimensional accuracy of the connecting portion between the transfer images of each pattern is increased, Therefore, disconnection or the like at the connecting portion can be prevented.

  In the second embodiment, the extension width of the first and second patterns 210 and 220 is set to about one third of the width of the transistor gate pattern 200. If the width is within the range, the pattern dimensions after transfer at the connecting portion can be substantially uniform, and the expansion width is not particularly limited.

  In the second embodiment, a plurality of rectangular patterns obtained by dividing the transistor gate pattern 200 are distributed to the first pattern 210 or the second pattern 220 according to the direction in the long side direction. However, when the shape of the rectangular pattern is a square, the rectangular pattern may be distributed to either the first pattern 210 or the second pattern 220.

  In the second embodiment, a set of complementary stencil masks for transferring a predetermined pattern is composed of two masks, but a set of complementary stencil masks is composed of three or more masks. Needless to say, the present embodiment can be applied to this case.

  In the second embodiment, the gate pattern is created. However, it goes without saying that the present embodiment can be applied to creation of other patterns.

(Third embodiment)
Hereinafter, a pattern forming method according to a third embodiment of the present invention will be described with reference to the drawings. Note that the pattern forming method of the present embodiment is a pattern forming method using the complementary stencil mask according to the first embodiment.

  FIGS. 5A to 5E are diagrams for explaining each step of a method for producing a complementary stencil mask used in the present embodiment.

  That is, in the present embodiment, first, pattern division of the transistor gate pattern 100 shown in FIG. 5A is performed, and the divided patterns are arranged in a set of complementary stencil masks. Specifically, by using the complementary stencil mask manufacturing method according to the first embodiment, the transistor gate pattern 100 is formed of a first pattern crossing portion as shown in FIGS. 5B and 5C. The pattern 110 is divided into a second pattern 120 composed of a rectangular pattern excluding the pattern intersection. That is, the first pattern data and the second pattern data are created.

  In the present embodiment, the end of the first pattern 110 that is in contact with the rectangular pattern of the second pattern 120 (that is, the segment of the first pattern 110) is, for example, 120 nm (converted value on the mask) in the direction of the rectangular pattern. By extending, new first pattern data is created. In other words, the second pattern data is newly created by retreating the end of the second pattern 120 in contact with the pattern intersection of the first pattern 110 (that is, the segment of the second pattern 120) by 120 nm.

  Next, the first and second complementary masks constituting a set of complementary stencil masks are created using each of the first and second pattern data. Specifically, as shown in FIG. 5D, the mask substrate 131 of the first complementary mask 130 is provided with a first opening 132 corresponding to the first pattern 110, and the second complementary mask. 140 mask substrates 141 are provided with second openings 142 corresponding to the second patterns 120. The width of each opening, that is, the pattern width (converted value on the mask) of the transistor gate pattern 100 is 260 nm.

  6A to 6D are cross-sectional views showing each step of the pattern forming method of the present embodiment.

  In the present embodiment, overlay exposure is performed using the two complementary masks 130 and 140 created as described above, using an electron beam reduction projection exposure apparatus having a 4 × reduction projection optical system.

  Specifically, first, as shown in FIG. 6A, a resist film 152 sensitive to an electron beam is applied on a silicon substrate 151 with a thickness of 300 nm.

  Next, the first complementary mask 130 is inserted into a reticle position in an electron beam exposure apparatus (not shown), and the silicon substrate 151 coated with the resist film 152 is placed on a wafer stage in the electron beam exposure apparatus. In the present embodiment, an electron beam 153 (see FIG. 6B) emitted from an electron gun in the electron beam exposure apparatus is accelerated at an acceleration voltage of 100 kV, and then passes through the illumination optical system to form a first complementary. The mask 130 is irradiated. The electron beam 153 that has passed through the opening 132 of the first complementary mask 130 is exposed on the silicon substrate 151 through the reduction projection optical system. At this time, the first transfer image 154 is formed as a latent image on the resist film 152 as shown in FIG. 6B.

  Next, after the first exposure with the first complementary mask 130 is completed, the first complementary mask 130 is taken out of the exposure apparatus and replaced with the second complementary mask 140, and then the second complementary mask 140. The exposure by is started again. Specifically, as shown in FIG. 6C, the electron beam 155 that has passed through the opening 142 of the second complementary mask 140 is projected onto the silicon substrate 151, and as a result, the resist film 152 has a first film. Two transfer images 156 are formed as latent images. At this time, there is an overlay error of about 15 nm between the first transfer image 154 and the second transfer image 156 due to the influence of the installation error of each complementary mask on the reticle stage and the position control error of the electron beam. occured. FIG. 7A is a plan view showing the first transfer image 154 and the second transfer image 156. FIG. 6C is a cross-sectional view taken along the line AB in FIG.

  Next, after the second exposure with the second complementary mask 140 is completed, the silicon substrate 151 is taken out of the exposure apparatus, and the resist film 152 is developed using, for example, an alkali developer, thereby FIG. As shown in (d), a resist pattern 157 is formed. FIG. 7B is a plan view showing the resist pattern 157.

  As can be seen from a comparison between FIG. 7A and FIG. 7B, the shape of the line ends and corners in the resist pattern 157 after resist development is compared to the first and second transfer images 154 and 156. Rounded. This is due to the influence of the blur of the electron beam and the development mechanism in which the development speed of the resist at the end of the line and at the corner is faster than the other parts. Therefore, the influence of the above-described overlay error on the resist pattern shape at the line end or corner portion becomes dull.

  As described above, according to the present embodiment, since the two complementary masks obtained by the complementary stencil mask creation method according to the first embodiment are used for overlay exposure with an electron beam, The same effect as in the first embodiment can be obtained. That is, the influence of the overlay error is suppressed, and as a result, the accuracy of the formed resist pattern 157 is increased. Moreover, since the stencil mask to be used has sufficient mechanical strength, the stencil mask can be used over a long period of time, so that the manufacturing cost can be reduced.

  Although the electron beam reduction projection exposure apparatus is used in the third embodiment, the same effect can be obtained by using an equal magnification electron beam projection exposure apparatus instead. Needless to say, the magnification of the projection optical system, the acceleration voltage of the electron beam, and the like are not particularly limited. Furthermore, conditions such as the film thickness of the resist are not particularly limited within the range sensitive to the electron beam.

  In the third embodiment, a set of complementary stencil masks for transferring a predetermined pattern is composed of two masks, but a set of complementary stencil masks is composed of three or more masks. Needless to say, the present embodiment can be applied to this case.

  In the third embodiment, the gate pattern is created. However, it goes without saying that the present embodiment can be applied to creation of other patterns.

(Fourth embodiment)
Hereinafter, a pattern forming method according to a fourth embodiment of the present invention will be described with reference to the drawings. Note that the pattern forming method of the present embodiment is a pattern forming method using the complementary stencil mask according to the second embodiment.

  FIGS. 8A and 8B are plan views showing a set of complementary stencil masks used in the present embodiment.

  That is, in the present embodiment, first, the first complementary mask 230 shown in FIG. 8A and the first complementary mask shown in FIG. 8B are used by using the complementary stencil mask manufacturing method according to the second embodiment. 2 complementary masks 240 are created. As shown in FIG. 8A, the first complementary mask 230 includes a mask substrate 231 and a first opening 232 provided in the mask substrate 231. The first opening 232 corresponds to a rectangular pattern (including an extended portion of the segment) whose long side extends in the vertical direction among predetermined patterns (gate patterns) to be transferred. On the other hand, as shown in FIG. 8B, the second complementary mask 240 includes a mask substrate 241 and a second opening 242 provided in the mask substrate 241. The second opening 242 corresponds to a rectangular pattern (including an extended portion of the segment) whose long side extends in the horizontal direction among predetermined patterns to be transferred. The width of each opening, that is, the pattern width of the gate pattern (converted value on the mask) is 260 nm.

  9A to 9D are cross-sectional views showing each step of the pattern forming method of this embodiment.

  In the present embodiment, overlay exposure using the two complementary masks 230 and 240 described above is performed using an electron beam reduction projection exposure apparatus having a 4 × reduction projection optical system.

  Specifically, first, as shown in FIG. 9A, a resist film 252 sensitive to an electron beam is applied on a silicon substrate 251 with a thickness of 300 nm.

  Next, the first complementary mask 230 is inserted into a reticle position in an electron beam exposure apparatus (not shown), and the silicon substrate 251 coated with the resist film 252 is placed on a wafer stage in the electron beam exposure apparatus. In the present embodiment, the electron beam 253 (see FIG. 9B) emitted from the electron gun in the electron beam exposure apparatus is accelerated at an acceleration voltage of 100 kV, and then passes through the illumination optical system to form the first complementary. The mask 230 is irradiated. Further, the electron beam 253 that has passed through the opening 232 of the first complementary mask 230 is exposed on the silicon substrate 251 through the reduction projection optical system. At this time, a first transfer image 254 is formed as a latent image on the resist film 252 as shown in FIG. 9B.

  Next, after the first exposure with the first complementary mask 230 is completed, the first complementary mask 230 is taken out of the exposure apparatus and replaced with the second complementary mask 240, and then the second complementary mask 240. The exposure by is started again. Specifically, as shown in FIG. 9C, the electron beam 255 that has passed through the opening 242 of the second complementary mask 240 is projected onto the silicon substrate 251, and as a result, the resist film 252 has a first film. A second transfer image 256 is formed as a latent image. At this time, there is an overlay error of about 10 nm between the first transfer image 254 and the second transfer image 256 due to the influence of the installation error of each complementary mask on the reticle stage and the position control error of the electron beam. occured. FIG. 10 is a plan view showing the first transfer image 254 and the second transfer image 256. FIG. 9C is a cross-sectional view taken along line CD in FIG. As shown in FIG. 10, there is no significant difference between the shape of the entire transfer image and the designed pattern shape (see FIG. 3).

  Next, after the second exposure with the second complementary mask 240 is completed, the silicon substrate 251 is taken out of the exposure apparatus, and the resist film 252 is developed using, for example, an alkali developer, thereby FIG. As shown in (d), a resist pattern 257 as designed is formed.

  As described above, according to the present embodiment, since the two complementary masks obtained by the complementary stencil mask creation method according to the second embodiment are used for overlay exposure with an electron beam, The same effect as in the second embodiment can be obtained. That is, the influence of the overlay error is suppressed, and as a result, the accuracy of the formed resist pattern 257 is increased. Moreover, since the stencil mask to be used has sufficient mechanical strength, the stencil mask can be used over a long period of time, so that the manufacturing cost can be reduced.

  In the fourth embodiment, the complementary stencil mask creation method according to the second embodiment is used. Instead, the complementary stencil mask creation method according to the first embodiment is used. The same resist pattern accuracy can be obtained.

  In the fourth embodiment, the electron beam reduction projection exposure apparatus is used. However, the same effect can be obtained by using an equal magnification electron beam projection exposure apparatus instead. Needless to say, the magnification of the projection optical system, the acceleration voltage of the electron beam, and the like are not particularly limited. Furthermore, conditions such as the film thickness of the resist are not particularly limited within the range sensitive to the electron beam.

  In the fourth embodiment, a set of complementary stencil masks for transferring a predetermined pattern is composed of two masks, but a set of complementary stencil masks is composed of three or more masks. Needless to say, the present embodiment can be applied to this case.

  In the fourth embodiment, the gate pattern is created. However, it goes without saying that the present embodiment can be applied to creation of other patterns.

(Fifth embodiment)
Hereinafter, a complementary stencil mask and a method for producing the same according to a fifth embodiment of the present invention will be described with reference to the drawings.

  FIG. 11A is a diagram showing a gate pattern to be transferred using the complementary stencil mask of this embodiment, and FIGS. 11B to 11E are diagrams of the complementary stencil mask of this embodiment. It is a figure for demonstrating each process of a creation method.

  That is, in the method of this embodiment, the wiring pattern 500 shown in FIG. 11A is divided and arranged in a set of complementary stencil masks.

  Specifically, first, as shown in FIG. 11B, the wiring pattern 500 is divided into a plurality of rectangular patterns (hereinafter referred to as rectangular patterns). This pattern division is basically performed by dividing the wiring pattern 500 along the width direction of the wiring pattern 500 at the bent portion of the wiring pattern 500. In other words, each rectangular pattern has the same width as the wiring pattern 500.

  Next, a pattern intersection 501 that is a location where the divided rectangular patterns are adjacent to each other is extracted. However, in the present embodiment, the pattern intersection where the corresponding rectangular pattern is a minute figure is left without being extracted.

  Next, as shown in FIG. 11C, an extended intersection 502 is formed by extending an end (that is, a segment of the intersection 501) in contact with the rectangular pattern in the intersection 501 to be divided in the direction of the rectangular pattern. create. Here, the extended width of the intersecting portion 501 is uniformly set to 40 nm, for example, on the wafer.

  Next, as shown in FIG. 11D, only the extended intersection 502 is extracted, and a first pattern 510 including the extracted extended intersection 502 is created. That is, first pattern data is created.

  Next, as shown in FIG. 11E, a second pattern 520 is created by subtracting the first pattern 510 from the wiring pattern 500 shown in FIG. That is, the second pattern data is created by subtracting the first pattern data from the original pattern data.

  Finally, the first and second masks constituting a set of complementary stencil masks are created using each of the first and second pattern data. Specifically, a first opening corresponding to the first pattern 510 is provided in the first mask, and a second opening corresponding to the second pattern 520 is provided in the second mask.

  By the way, if the desired wiring pattern 500 shown in FIG. 11A is simply expressed using dots and lines, the first pattern 510 shown in FIG. On the other hand, the second pattern 520 shown in FIG. 11E is composed of lines that are the main part of the desired pattern 500. Therefore, when overlay exposure is performed using a complementary mask divided into two corresponding to the first and second patterns 510 and 520, the influence of overlay error can be minimized. Therefore, the original pattern (wiring pattern 500) can be restored more accurately.

  In this embodiment, as shown in FIGS. 11D and 11E, the original complicated pattern is divided into a first pattern 510 that is an intersection of the patterns and a second pattern that is a simple rectangular pattern. Since it is divided into the pattern 520 and arranged on each complementary mask, a sufficient mechanical strength is maintained in each complementary mask. Further, as shown in FIG. 11C, the following effects can be obtained by extending the intersection 501 to, for example, about 160 nm (converted value on the mask). That is, when the second pattern 520 is created by subtracting the first pattern 510 including the extended intersection portion 502 from the wiring pattern 500, the interval between the linear patterns constituting the second pattern 520 is sufficiently large. Can be taken to. Accordingly, in the second mask, since the interval between the second openings corresponding to the second pattern 520 is widened, the mechanical strength of the mask is further increased.

  As described above, according to the present embodiment, a complex polygon pattern existing in a predetermined pattern (wiring pattern 500) to be transferred can be divided and placed on each complementary mask. For this reason, local stress concentration in the complementary mask can be prevented, so that the mask can be prevented from being deformed or broken. Furthermore, in order to distribute the main part of the desired pattern (second pattern 520 composed of linear patterns) onto one complementary mask (second mask), overlay exposure is performed using each complementary mask. In this case, it is possible to prevent the resolution failure of the main pattern portion, that is, the pattern transfer defect, caused by the overlay error. That is, the fidelity in the transfer shape of a desired pattern can be improved.

  In the fifth embodiment, the width for expanding the pattern intersection 501 can be arbitrarily set within a range in which the mechanical strength of the complementary mask is maintained.

  In the fifth embodiment, after the first and second patterns 510 and 520 are created, the end portion of the first pattern 510 that is in contact with the second pattern 520 (that is, the segment of the first pattern 510) is used. A step of forming the third pattern by extending in the direction of the second pattern 520 may be further provided. In this case, instead of the first pattern 110, an opening corresponding to the third pattern may be provided in the first mask. In this way, when performing overlay exposure using each complementary stencil mask, the extended portion of the pattern acts as a “margin”, thus preventing disconnection at the connection between the transferred images of each pattern. Can do. At this time, the extended width of the pattern is preferably equal to or smaller than the width of the wiring pattern 500.

  In the fifth embodiment, a set of complementary stencil masks for transferring a predetermined pattern is composed of two masks, but a set of complementary stencil masks is composed of three or more masks. Needless to say, the present embodiment can be applied to this case.

  In the fifth embodiment, the wiring pattern is created. However, it goes without saying that the present embodiment can be applied to creating other patterns.

(Sixth embodiment)
In the electron beam exposure method, it is widely known that a “beam blur” phenomenon occurs in which a beam is blurred because electrons repel each other when the electron beam passes through a projection lens. Here, the magnitude of the beam blur largely depends on the amount of current passing through the projection lens, and also depends on other optical system parameters such as the distance between the lens and the wafer.

  The present embodiment is an invention that also focuses on the problem of “beam blur” in electron beam exposure using a complementary stencil mask. The following description is based on the pattern forming method according to the fourth embodiment.

  In the fourth embodiment, a first complementary mask 230 configured with a long pattern in the vertical direction (vertical direction) and a second complementary mask 240 configured with a long pattern in the horizontal direction (horizontal direction). And were used. Here, the aperture ratio (area ratio of the open portion) of the first complementary mask 230 is about 20%, and the aperture ratio of the second complementary mask 240 is about 10%. When the amount of current applied to the mask is constant, the amount of current passing through the mask is proportional to the aperture ratio of the mask, so that the amount of current passing through the first complementary mask 230 passes through the second complementary mask 240. The amount of current to be doubled. Therefore, the beam blur when the first complementary mask 230 is used is nearly twice as large as the beam blur when the second complementary mask 240 is used. When the exposure with the first complementary mask 230 and the exposure with the second complementary mask 240 are performed while the amount of current applied to the mask is constant as described above, a transfer image as shown in FIG. 12 is obtained. As shown in FIG. 12, the dimension of the first transfer image 254 by the first complementary mask 230 becomes thick due to large beam blur. On the other hand, the second transfer image 256 by the second complementary mask 240 becomes sharp because the beam blur is small. As described above, when the contrast changes between the first transfer image 254 and the second transfer image 256 due to the difference in beam blur, the dimensions of the first transfer image 254 and the second transfer image 254 There is a problem in that there is a difference between the dimensions of the transfer image 256. In addition, when the absolute value of the beam blur is larger than the design value of the pattern dimension, there is a problem that the resolution of the pattern is extremely deteriorated.

  Therefore, in this embodiment, the aperture ratio of each complementary mask is calculated in advance, and based on the calculation result, the beam blur is equal or almost equal in the exposure using each of the first and second complementary masks 230 and 240. The amount of current applied to each mask is adjusted so that In the fourth embodiment, since the design value of the width (minimum dimension) of the gate pattern to be transferred is 65 nm, in this embodiment, the beam blur is equal to or smaller than the pattern design width so as to obtain a sufficient exposure margin. The amount of current applied to each of the first and second complementary masks 230 and 240 was adjusted so as to be about 40 nm. Specifically, by adjusting the amount of current applied to the first complementary mask 230 to 10 μA and adjusting the amount of current applied to the second complementary mask 240 to 20 μA and performing exposure, the beam blur is approximately 40 nm. As shown in FIG. 13, the width of the first transfer image 254 and the width of the second transfer image 256 became uniform. Also in the resist pattern after the development processing, the dimension of the vertically long line part and the dimension of the horizontally long line part were both 65 nm as designed, and a uniform pattern dimension was obtained. In addition, a sufficiently high margin of 20% was obtained for the exposure margin.

  As described above, according to the present embodiment, since the amount of current is adjusted so that the blur of the electron beam in each exposure step is constant, the uniformity of the dimension of the transferred resist pattern can be improved. . Further, since the blur of the electron beam is set to be equal to or less than the pattern dimension design value, a high exposure amount margin can be obtained.

  In the sixth embodiment, the amount of current is adjusted so that the electron beam blur in each exposure step is equal. Instead, the parameters of the projection optical system of the exposure apparatus may be adjusted. Further, although the blur of the electron beam is set to 40 nm, the present invention is not limited to this, and a sufficient exposure margin can be obtained by setting the blur of the electron beam to a pattern dimension design value or less.

  The sixth embodiment is directed to the pattern forming method according to the fourth embodiment (pattern forming method using the complementary stencil mask according to the second embodiment). The same effect can be obtained when the pattern forming method according to the third embodiment (the pattern forming method using the complementary stencil mask according to the first embodiment) is targeted.

  As described above, the present invention relates to a complementary stencil mask, a method for producing the same, and a pattern forming method, and is particularly useful when a fine pattern such as a logic gate pattern or a multilayer wiring pattern is formed.

It is a figure which shows the gate pattern which is going to transfer using the complementary stencil mask which concerns on the 1st Embodiment of this invention. (A)-(e) is a figure for demonstrating each process of the production method of the complementary stencil mask which concerns on the 1st Embodiment of this invention. It is a figure which shows the gate pattern which is going to transfer using the complementary stencil mask which concerns on the 2nd Embodiment of this invention. (A)-(c) is a figure for demonstrating each process of the preparation method of the complementary stencil mask which concerns on the 2nd Embodiment of this invention. (A)-(e) is a figure for demonstrating each process of the production method of the complementary stencil mask used with the pattern formation method which concerns on the 3rd Embodiment of this invention. (A)-(d) is sectional drawing which shows each process of the pattern formation method which concerns on the 3rd Embodiment of this invention. (A) is a top view which shows the 1st transfer image and the 2nd transfer image which were obtained by the pattern formation method concerning the 3rd Embodiment of this invention, (b) is the 3rd of this invention. It is a top view which shows the resist pattern obtained by the pattern formation method concerning this embodiment. (A) And (b) is a top view which shows the complementary stencil mask used with the pattern formation method concerning the 3rd Embodiment of this invention. (A)-(d) is sectional drawing which shows each process of the pattern formation method which concerns on the 3rd Embodiment of this invention. It is a top view which shows the 1st transfer image and 2nd transfer image which were obtained by the pattern formation method which concerns on the 3rd Embodiment of this invention. (A) is a figure which shows the gate pattern which is going to transfer using the complementary stencil mask which concerns on the 5th Embodiment of this invention, (b)-(e) is the 5th Embodiment of this invention. It is a figure for demonstrating each process of the production method of the complementary stencil mask which concerns. It is a figure for demonstrating the influence of beam blur. It is a figure which shows the transfer image obtained by performing the superposition exposure using the 1st complementary mask and the 2nd complementary mask in the pattern formation method concerning the 6th Embodiment of this invention. (A) is a figure which shows the pattern which is going to transfer using the conventional complementary stencil mask, (b) is a top view which shows the conventional complementary stencil mask. (A)-(e) is a figure for demonstrating each process of the preparation method of the conventional complementary stencil mask. It is a figure for demonstrating the problem in the conventional complementary stencil mask.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Gate pattern 101 Pattern crossing part 102 Extended crossing part 110 1st pattern 120 2nd pattern 130 1st complementary mask 131 Mask substrate 132 1st opening part 140 2nd complementary mask 141 Mask board | substrate 142 2nd opening Part 151 Silicon substrate 152 Resist film 153 Electron beam 154 First transfer image 155 Electron beam 156 Second transfer 157 Resist pattern 200 Gate pattern 210 First pattern 211 Extension part 220 Second pattern 221 Extension part 230 First part Complementary mask 231 Mask substrate 232 First opening 240 Second complementary mask 241 Mask substrate 242 Second opening 251 Silicon substrate 252 Resist film 253 Electron beam 254 First transfer image 255 Electron beam 256 2 of the transferred image 257 resist pattern 500 wiring pattern 501 pattern intersection 502 extended intersection 510 first pattern 520 second pattern

Claims (15)

A method of creating a set of complementary stencil masks for transferring a predetermined pattern,
Dividing the predetermined pattern into a plurality of square patterns;
Extracting a pattern intersection that is an adjacent part of the rectangular patterns, and creating a first pattern composed of the extracted pattern intersection; and
Creating a second pattern by subtracting the first pattern from the predetermined pattern;
The first mask constituting the set of complementary stencil masks is provided with a first opening corresponding to the first pattern, and the second mask constituting the set of complementary stencil masks includes the first mask. And a step of providing a second opening corresponding to the second pattern. A method for producing a complementary stencil mask, comprising:   2. The complementary type according to claim 1, wherein in the step of creating the first pattern, a pattern intersection having an area smaller than an area of a corresponding rectangular pattern is extracted from the pattern intersections. How to create a stencil mask. Creating a third pattern by extending an end of the first pattern that contacts the second pattern in the direction of the second pattern;
A step of creating a fourth pattern by subtracting the third pattern from the predetermined pattern,
In the step of providing the first opening and the second opening, the first opening corresponding to the third pattern is provided in the first mask instead of the first pattern, and 2. The method for producing a complementary stencil mask according to claim 1, wherein, instead of the second pattern, the second opening corresponding to the fourth pattern is provided in the second mask. Forming a fifth pattern by extending an end portion of the third pattern in contact with the fourth pattern in the direction of the fourth pattern; and the third pattern in the fourth pattern; Further comprising at least one step of forming a sixth pattern by extending a contact end in the direction of the third pattern;
The step of providing the first opening and the second opening includes the step of providing the first mask with the first opening corresponding to the fifth pattern instead of the third pattern, And at least one of the steps of providing the second opening corresponding to the sixth pattern in the second mask instead of the fourth pattern. A method for producing the complementary stencil mask as described.   5. The complementary stencil mask creation method according to claim 4, wherein an extension width of each of the third pattern and the fourth pattern is equal to or less than a width of the predetermined pattern. A method of creating a set of complementary stencil masks for transferring a predetermined pattern,
Dividing the predetermined pattern into a plurality of square patterns;
Extracting a rectangular pattern having a long side extending in a vertical direction from the plurality of rectangular patterns, and creating a first pattern composed of the extracted rectangular pattern;
Extracting a rectangular pattern having a long side extending in the horizontal direction from the plurality of rectangular patterns, and creating a second pattern composed of the extracted rectangular pattern;
The first mask constituting the set of complementary stencil masks is provided with a first opening corresponding to the first pattern, and the second mask constituting the set of complementary stencil masks includes the first mask. And a step of providing a second opening corresponding to the second pattern. A method for producing a complementary stencil mask, comprising: Forming a third pattern by extending an end of the first pattern in contact with the second pattern in the direction of the second pattern; and the first pattern in the second pattern; Further comprising at least one step of forming a fourth pattern by extending a contact end in the direction of the first pattern;
Providing the first opening and the second opening includes providing the first opening corresponding to the third pattern in the first mask instead of the first pattern; And at least one step of providing the second opening corresponding to the fourth pattern in the second mask instead of the second pattern. A method for producing the complementary stencil mask as described.   8. The method for producing a complementary stencil mask according to claim 7, wherein the extended width of each of the first pattern and the second pattern is equal to or smaller than the width of the predetermined pattern. A set of complementary stencil masks for transferring a predetermined pattern,
The first mask constituting the set of complementary stencil masks has a first opening corresponding to a pattern intersection which is an adjacent portion of a plurality of rectangular patterns obtained by dividing the predetermined pattern. And
The second mask constituting the set of complementary stencil masks has a second opening corresponding to a pattern obtained by subtracting the pattern intersection from the predetermined pattern. Stencil mask.   The complementary stencil mask according to claim 9, wherein an area of the pattern intersection is smaller than an area of a corresponding rectangular pattern. A set of complementary stencil masks for transferring a predetermined pattern,
The first mask constituting the set of complementary stencil masks has a first opening corresponding to a rectangular pattern having a long side extending in a vertical direction among a plurality of rectangular patterns obtained by dividing the predetermined pattern. Part
The second mask constituting the set of complementary stencil masks has a second opening corresponding to a rectangular pattern having a long side extending in the horizontal direction among the plurality of rectangular patterns. Complementary stencil mask. A pattern forming method using a set of complementary stencil masks for transferring a predetermined pattern,
Applying a resist film on the substrate;
Irradiating the resist film with a first electron beam through a first mask constituting the set of complementary stencil masks;
Irradiating the resist film with a second electron beam through a second mask constituting the set of complementary stencil masks;
Forming a resist pattern by developing the resist film irradiated with the first electron beam and the second electron beam,
The first mask has a first opening corresponding to a pattern intersection that is an adjacent portion of a plurality of rectangular patterns obtained by dividing the predetermined pattern,
The pattern forming method, wherein the second mask has a second opening corresponding to a pattern obtained by subtracting the pattern intersection from the predetermined pattern. A pattern forming method using a set of complementary stencil masks for transferring a predetermined pattern,
Applying a resist film on the substrate;
Irradiating the resist film with a first electron beam through a first mask constituting the set of complementary stencil masks;
Irradiating the resist film with a second electron beam through a second mask constituting the set of complementary stencil masks;
Forming a resist pattern by developing the resist film irradiated with the first electron beam and the second electron beam,
The first mask has a first opening corresponding to a rectangular pattern having a long side extending in a vertical direction among a plurality of rectangular patterns obtained by dividing the predetermined pattern,
The pattern forming method, wherein the second mask has a second opening corresponding to a rectangular pattern having a long side extending in a horizontal direction among the plurality of rectangular patterns.   The first electron beam or the blur so that the blur of the first electron beam passing through the first mask is equivalent to the blur of the second electron beam passing through the second mask. 14. The pattern forming method according to claim 12, further comprising a beam blur adjusting step of adjusting a current amount of the second electron beam or a projection optical system of the exposure apparatus.   The pattern formation according to claim 14, wherein the beam blur adjusting step includes a step of reducing blur of the first electron beam and the second electron beam to be smaller than a minimum dimension of the predetermined pattern. Method.

Images