Patent Publication Number: US-2013249918-A1

Title: Method of forming drawing pattern, method of generating drawing data, and drawing data generating device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2012-068096, filed on Mar. 23, 2012; the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments relates generally to a method of forming a drawing pattern, a method of generating drawing data, and a drawing data generating device. 
     BACKGROUND 
     As pattern data used in a lithography process performed when a semiconductor device is manufactured, there are mask data of a photomask, mask data of an imprint mask (template), data of a pattern drawn on a substrate such as a wafer using electron beams, and the like. 
     The pattern data is data of a pattern drawn on a photomask, a template, a wafer, or the like, and the pattern data of each drawing shot is generated by dividing the whole pattern data for each drawing shot. Thus, by drawing a pattern that corresponds to the pattern data on the substrate for each drawing shot, an on-substrate pattern is formed. 
     In such an on-substrate pattern, there are joints between each drawing shots, and, in a case where the on-substrate pattern is formed, a variation in the size of the pattern may easily occur due to the joints of the drawing shots. Accordingly, it is desired that an on-substrate pattern having a desired size is formed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram that illustrates the concept of a drawing pattern generating process according to an embodiment; 
         FIG. 2  is a block diagram that illustrates the configuration of a drawing data generating device according to an embodiment; 
         FIG. 3  is a flowchart that illustrates the processing sequence of the process of a method of forming a drawing pattern; 
         FIG. 4  is a flowchart that illustrates the processing sequence of a drawing data generating process; 
         FIG. 5  is diagram that illustrates an example of a multiple exposure setting area; 
         FIG. 6  is a diagram that illustrates set positions of drawing shots; 
         FIG. 7  is a diagram that illustrates a line end setting process using the addition of offsets; 
         FIG. 8  is a diagram that illustrates a line end setting process using the addition of protruded patterns; 
         FIG. 9  is a diagram that illustrates a line end setting process using the expansion and contraction of line ends; 
         FIG. 10  is a diagram that illustrates a line end setting process using the addition of dummy patterns; 
         FIG. 11  is a diagram that illustrates a process of setting a plurality of separation positions for pattern data; 
         FIG. 12  is a diagram that illustrates drawing data generated based on pattern data; 
         FIG. 13  is a diagram that illustrates the shape of a drawing pattern formed on a substrate by using a plurality of types of drawing data; 
         FIG. 14  is a diagram that illustrates a process of setting separation positions for each one pattern; and 
         FIG. 15  is a diagram that illustrates the hardware configuration of a drawing data generating device. 
     
    
    
     DETAILED DESCRIPTION 
     According to an embodiment, a method of forming a drawing pattern is provided. In the method of forming a drawing pattern, drawing data is generated based on pattern data by setting the positions of drawing shots for the pattern data of a drawing pattern to be drawn on a substrate. Then, by drawing a drawing pattern corresponding to the drawing data on the substrate, the drawing pattern is formed on the substrate. When the drawing data is to be generated, by setting the position of a drawing shot to a position that differs for each drawing data, a plurality of types of drawing data are generated based on one type of pattern data. In addition, when the drawing pattern is formed, a multiple exposure is performed for the substrate by using the plurality of types of drawing data. 
     Hereinafter, a method of forming a drawing pattern, a method of generating drawing data, and a drawing data generating device according to embodiments will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments. 
     Embodiments  
       FIG. 1  is a diagram that illustrates the concept of a drawing pattern generating process according to an embodiment. Pattern data  31  of an on-substrate pattern to be formed (drawn) on a substrate (a photomask, a template, a wafer, or the like) is generated in Step ST 1 . Thereafter, by setting predetermined separation positions in the pattern data  31 , the pattern data  31  is divided into areas for each drawing shot. In this embodiment, by dividing the pattern data  31  at various separation positions, a plurality of types of drawing data (graphic data such as VSB data)  32 A and  32 B of which the division positions are shifted are generated in Step ST 2 . Each generated drawing data is pattern data acquired by dividing the pattern data  31  according to drawing shots. When a drawing pattern that corresponds to the pattern data  31  is formed on the substrate, a drawing pattern is formed on the substrate for each drawing shot. Here, a case will be described in which two types of drawing data are generated by using two types of separation methods. 
     For example, by dividing the pattern data  31  into data of three areas using two separation positions  33 A and  34 A, which is a first separation method, first drawing data  32 A is generated. From this, the first drawing data  32 A is configured by drawing pattern areas  36 A,  37 A, and  38 A. 
     Similarly, by dividing the pattern data  31  into data of four areas using three separation positions  33 B,  34 B, and  35 B, which is a second separation method, second drawing data  32 B is generated. From this, the second drawing data  32 B is configured by drawing pattern areas  36 B,  37 B,  38 B, and  39 B. 
     In other words, by dividing the pattern data  31  into three drawing shots, the first drawing data  32 A in which the drawing pattern areas  36 A to  38 A are set is generated. Similarly, by dividing the pattern data  31  into four drawing shots, the second drawing data  32 B in which the drawing pattern areas  36 B to  39 B are set is generated. 
     In this case, the separation positions  33 A and  34 A of the first drawing data  32 A and the separation positions  33 B,  34 B, and  35 B of the second drawing data  32 B are set to different separation positions. In other words, any one of the drawing pattern areas  36 A to  38 A is set to an area that is different from the drawing pattern areas  36 B and  39 B. In this way, by setting the positions of the drawing shots to positions different for each drawing data, a plurality of types of drawing data are generated based on one type of the pattern data  31  in Step ST 3 . 
     Thereafter, a drawing pattern is formed on the substrate for each drawing shot. More specifically, by drawing (for example, EB drawing) drawing patterns corresponding to the drawing data, the drawing patterns are formed on the substrate. 
     For example, a drawing pattern is formed on a substrate by using the first drawing data  32 A, and thereafter, a drawing pattern is formed on the substrate by using the second drawing data  32 B. Thereafter, a multiple exposure is performed for the substrate by using the first drawing data  32 A and the second drawing data  32 B. In other words, after a first drawing pattern is drawn using the first drawing data  32 A, a second drawing pattern is drawn using the second drawing data  32 B on the first drawing pattern. 
     For example, a drawing pattern  41 A corresponding to the drawing pattern area  38 A is formed, and, thereafter, a drawing pattern  42 A corresponding to the drawing pattern area  37 A is formed. In addition, a drawing pattern  43 A corresponding to the drawing pattern area  36 A is formed. Thereafter, a drawing pattern  41 B corresponding to the drawing pattern area  39 B is formed, and, thereafter, a drawing pattern  42 B corresponding to the drawing pattern area  38 B is formed. Furthermore, a drawing pattern  43 B corresponding to the drawing pattern area  37 B is formed, and, thereafter, a drawing pattern  44 B corresponding to the drawing pattern area  36 B is formed in Step ST 3 . In this way, an on-substrate pattern  45  acquired by overlapping the first drawing pattern and the second drawing pattern is formed on the substrate in Step ST 4 . 
     In a case where the separation positions of the first drawing data and the second drawing data overlap each other, the separation positions of the first drawing pattern and the second drawing pattern formed on the substrate overlap each other as well. When the separation positions of the drawing patterns overlap each other, a size variation in the pattern size becomes obvious near the separation position (shot joining portion), whereby a discrepancy in the size may easily occur. Particularly, in an imprint such as nano-imprint lithography (NIL), a template having a same-size mask is used, and accordingly, a size variation in the pattern size is remarkable. 
     In this embodiment, a plurality of types of drawing data are generated by shifting separation positions (division positions) of the drawing patterns, and multiple drawing is performed, whereby a size discrepancy (a variation caused by the connection of shots) in the pattern size near the separation position can be decreased. 
       FIG. 2  is a block diagram that illustrates the configuration of a drawing data generating device according to an embodiment. The drawing data generating device  1  is a computer that generates a plurality of types of drawing data based on pattern data of a pattern to be formed on a substrate or the like. The drawing data generating device  1  according to this embodiment generates a plurality of types of drawing data based on one pattern data by shifting the separation positions of the drawing pattern to various positions. In other words, the drawing data generating device  1  generates a plurality of types of drawing data by shifting the positions of drawing shots set for pattern data within the pattern data. 
     In description presented below, a case will be described in which the drawing data generating device  1  generates a plurality of types of drawing data based on pattern data of a template pattern. Accordingly, the drawing data generated by the drawing data generating device  1  is data of a pattern drawn in a template (original form). 
     The drawing data generating device  1  includes an input unit  11 , a pattern data storing unit  12 , a target area extracting unit  13 , a line end setting unit  14 , a division area setting unit (drawing shot setting unit)  15 , and an output unit  16 . The input unit  11  receives pattern data transmitted from an external device (a pattern data generating device generating the pattern data or the like) as an input and transmits the pattern data to the pattern data storing unit  12 . The pattern data storing unit  12  is a memory storing pattern data or the like. 
     The target area extracting unit  13  extracts an area (a multiple exposure setting area for which multiple exposure is performed) in which a plurality of types of drawing data are generated from the pattern data (a pattern data area  100  to be described later) stored inside the pattern data storing unit  12 . The target area extracting unit  13  extracts an area (an area in which a fine pattern is arranged) in which drawing accuracy is required from the pattern data as a multiple exposure setting area. The target area extracting unit  13  transmits the extracted multiple exposure setting area to the line end setting unit  14 . 
     The line end setting unit  14  sets line ends (pattern ends) in each pattern within the multiple exposure setting area. The line end is a reference position for setting a separation position in the pattern data. When the separation positions are set, the multiple exposure setting area is separated such that the line ends coincide with the shot separation of drawing shots. 
     The line end setting unit  14  according to this embodiment groups the inside of the multiple exposure setting area for each pattern group. The line end setting unit  14 , for example, groups patterns inside the multiple exposure setting area into a plurality of sets such that patterns, which are adjacent to each other, having the same pattern pitch are grouped into the same set. The line end setting unit  14  extracts one pattern from each pattern group that has been grouped and sets N types (here, N is a natural number of two or more) of line ends for each extracted pattern. The line end setting unit  14  transmits information relating to the multiple exposure setting area and the set positions of line ends to the division area setting unit  15 . 
     The division area setting unit  15  divides each pattern group formed within the multiple exposure setting area into drawing shots based on the positions of the line ends set by the line end setting unit  14 . More specifically, after the separation positions are set such that the line ends coincide with the shot separation of the drawing shots, the division area setting unit  15  sets other separation positions such that drawing shots are adjacently arranged. From this, separation positions are set for each pattern data of each pattern group. In other words, each pattern group is divided into a plurality of drawing shots by the shot separation of a plurality of drawing shots. As a result, drawing shots are set in each pattern formed inside the multiple exposure setting area. 
     In this way, the division area setting unit  15  generates drawing data by dividing the multiple exposure setting area into a plurality of drawing shots (drawing pattern areas). The division area setting unit  15  according to this embodiment sets separation positions for each set line end. From this, the division area setting unit  15  generates N types of drawing data for each pattern group. The division area setting unit  15  transmits the generated N types of drawing data to the output unit  16 . The output unit  16  outputs the drawing data to an external device (a drawing device or the like). 
       FIG. 3  is a flowchart that illustrates the processing sequence of a drawing pattern forming process. Design data (layout pattern data) of a pattern to be formed on a substrate such as a template is generated in Step S 1 . In addition, by performing mask data preparation (MDP) or optical proximity correction (OPC) for the design data, pattern data  31  is generated in Step S 2 . 
     Thereafter, the drawing data generating device  1  divides the pattern data  31  at predetermined separation positions, thereby dividing the pattern data  31  into areas for each drawing shot in Step S 3 . The drawing data generating device  1  performs various data divisions, thereby generating a plurality of types of drawing data in Step S 4 . 
     A drawing device performing electron beam (EB) drawing for a substrate performs a multiple exposure for the substrate by using a plurality of types of drawing data that has been generated in Step S 5 . For example, in a case where N types of drawing data are generated, the drawing device performs N times of multiple exposures by sequentially using the N types of drawing data. From this, a drawing pattern is formed on the substrate. 
       FIG. 4  is a flowchart that illustrates the processing sequence of a drawing data generating process. The input unit  11  of the drawing data generating device  1  receives pattern data transmitted from an external device as an input and transmits the pattern data to the pattern data storing unit  12 . The pattern data storing unit  12  stores the pattern data. 
     The target area extracting unit  13  extracts a multiple exposure setting area, which is an area for which a plurality of types of division setting is performed, from the pattern data area  100  arranged inside the pattern data storing unit  12  based on a predetermined extraction condition and transmits the multiple exposure setting area to the line end setting unit  14  in Step S 11 . 
       FIG. 5  is diagram that illustrates an example of the multiple exposure setting area. The target area extracting unit  13  extracts an area (for example, an area in which a pattern is formed at a minimum pitch) in which a fine pattern of a size smaller than a predetermined size is arranged from the pattern data area  100  as the multiple exposure setting area  5 . 
     The line end setting unit  14  groups the inside of the multiple exposure setting area  5  into pattern groups and extracts one arbitrary pattern from each pattern group and sets a plurality of types (N types) of line ends for the extracted one pattern in Step S 12 . The line end setting unit  14  transmits information relating to the multiple exposure setting area  5  and the set positions of line ends to the division area setting unit  15 . 
     The division area setting unit  15  sets drawing shots in the multiple exposure setting area  5  based on the positions of the line ends that are set by the line end setting unit  14  in Step S 13 , thereby generating drawing data. The division area setting unit  15  according to this embodiment sets drawing shots for each line end, thereby generating drawing data corresponding to the same number (N) as the number of set line ends. 
     Here, the set positions of the drawing shots will be described.  FIG. 6  is a diagram illustrating set positions of drawing shots.  FIG. 6  illustrates an example of the pattern data  31  arranged inside the multiple exposure setting area  5 . A pattern data area other than the multiple exposure setting area  5  also has a configuration that is the same as that of the multiple exposure setting area  5  illustrated in  FIG. 5 . 
     The multiple exposure setting area  5  is configured by one or a plurality of frames  51 B having a predetermined frame width  51 A. The frame  51 B is a drawing area for which drawing can be performed in accordance with the movement of a main inclination area according to the movement of a stage. In addition, in each frame  51 B, a plurality of subfields  52 B having a predetermined subfield width  52 A is set. In other words, the multiple exposure setting area  5  is divided into a plurality of frames  51 B, and each frame  51 B is divided into a plurality of subfields  52 B. From this, each pattern data  31  is divided into a plurality of frames  51 B and is divided into a plurality of subfields  52 B. 
     In addition, each pattern data  31  is separated into a plurality of drawing shots  53 B having a predetermined shot width  53 A. In this way, the pattern data  31  is separated into frames  51 B, subfields  52 B, and drawing shots  53 B. In other words, the pattern data  31  is divided at frame boundaries that are boundaries between frames  51 B, subfield boundaries that are boundaries between subfields  52 B, and shot boundaries that are boundaries of drawing shots  53 B. A large pattern having a pattern pitch larger than a predetermined value in the multiple exposure setting area  5  may be divided into drawing shots larger than the drawing shot  53 B. 
     Next, an example of a line end setting process will be described. The line end setting unit  14 , for example, sets line ends for the pattern data  31  (line end setting pattern) arranged inside the multiple exposure setting area  5  using a method of (1) adding offsets to the line ends, (2) adding protruded patterns, (3) expanding or contracting the line ends, (4) adding dummy patterns, or the like. 
     (1) Adding Offset to Line End 
       FIG. 7  is a diagram that illustrates the line end setting process using the addition of offsets.  FIG. 7  illustrates the line end setting process in a case where the line ends are set by adding offsets to the line ends. In a case where offsets are added to line end setting patterns arranged inside the multiple exposure setting area  5 , the line end setting unit  14  sets a plurality of types of offset sizes (offset sizes that are mutually different) for the line end setting patterns.  FIG. 7  illustrates a case in which a first offset size  25 A, a second offset size  25 B, and a third offset size  25 C having mutually different sizes are set for the line end setting patterns. 
     When the first offset size  25 A is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  21 A by moving from the original line end  20  by the first offset size  25 A. When drawing shots are set by using the line end  21 A as the reference, drawing data  61 A having a separation position  71 A is formed. 
     Similarly, when the second offset size  25 B is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  21 B by moving from the original line end  20  by the second offset size  25 B. When drawing shots are set by using the line end  21 B as the reference, drawing data  61 B having a separation position  71 B is formed. 
     Similarly, when the third offset size  25 C is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  21 C by moving from the original line end  20  by the third offset size  25 C. When drawing shots are set by using the line end  21 C as the reference, drawing data  61 C having a separation position  71 C is formed. 
     (2) Adding Protruded Pattern 
       FIG. 8  is a diagram that illustrates the line end setting process using the addition of protruded patterns.  FIG. 8  illustrates the line end setting process in a case where the line ends are set by adding protruded patterns to line end setting patterns. In a case where the protruded patterns are added to the line end setting pattern, the line end setting unit  14  adds the protruded patterns to various positions of the line end setting pattern.  FIG. 8  illustrates a case in which the protruded patterns  26 A,  26 B, and  26 C are set at a first position  22 A, a second position  22 B, and a third position  22 C, which are mutually different positions, for the line end setting pattern. 
     The protruded patterns  26 A,  26 B, and  26 C are fine patterns that do not influence the on-substrate pattern. In a case where the substrate is a photomask, the protruded patterns  26 A,  26 B, and  26 C, for example, are fine patterns that are not resolved on the wafer. On the other hand, in a case where the substrate is a template, the protruded patterns  26 A,  26 B, and  26 C, for example, are fine patterns in which a resist is not filled. 
     The line end setting unit  14  sets the position of the protruded patterns as line ends. From this, when the protruded pattern  26 A is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  22 A located at a position that is approximately the same as the position of the protruded pattern  26 A. When drawing shots are set by using the line end  22 A as the reference, drawing data  62 A having a separation position  72 A is formed. 
     Similarly, when the protruded pattern  26 B is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  22 B located at a position that is approximately the same as the position of the protruded pattern  26 B. When drawing shots are set by using the line end  22 B as the reference, drawing data  62 B having a separation position  72 B is formed. 
     Similarly, when the protruded pattern  26 C is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  22 C located at a position that is approximately the same as the position of the protruded pattern  26 C. When drawing shots are set by using the line end  22 C as the reference, drawing data  62 C having a separation position  72 C is formed. 
     (3) Expanding or Contracting Line End 
       FIG. 9  is a diagram that illustrates a line end setting process using the expansion and contraction of line ends.  FIG. 9  illustrates the line end setting process in a case where the line ends are set by expanding or contracting the line ends of the line end setting patterns in the longitudinal direction. In a case where the line end of the line end setting pattern is expanded or contracted, the line end setting unit  14  sets a plurality of types of expansion/contraction sizes as the line end setting patterns.  FIG. 9  illustrates cases where a first expansion/contraction size  27 A, a second expansion/contraction size  27 B, and a third expansion/contraction size  27 C are set for the line end setting pattern. 
     When the first expansion/contraction size  27 A is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  23 A by moving from the original line end  20  by the first expansion/contraction size  27 A. When drawing shots are set by using the line end  23 A as the reference, drawing data  63 A having a separation position  73 A is formed. 
     Similarly, when the second expansion/contraction size  27 B is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  23 B by moving from the original line end  20  by the second expansion/contraction size  27 B. When drawing shots are set by using the line end  23 B as the reference, drawing data  63 B having a separation position  73 B is formed. 
     Similarly, when the third expansion/contraction size  27 C is set for the line end setting pattern, the line end of the line end setting pattern becomes a line end  23 C by moving from the original line end  20  by the third expansion/contraction size  27 C. When drawing shots are set by using the line end  23 C as the reference, drawing data  63 C having a separation position  73 C is formed. 
     For example, since only one exposure is performed at the time of performing multiple exposures, a pattern (expanded portion) in which the first expansion/contraction size  27 A is set out of the line end setting patterns has a little influence on the on-wafer pattern. In this way, even in a case where the line end setting pattern is set, after multiple exposures are performed, there is a little influence on the wafer image accompanied with the expansion or contraction of the line end. 
     (4) Adding Dummy Pattern 
       FIG. 10  is a diagram that illustrates a line end setting process using the addition of dummy patterns.  FIG. 10  illustrates the line end setting process in a case where the line end is set by adding dummy patterns near the line end setting patterns. In a case where a dummy pattern is to be added near the line end setting pattern, the line end setting unit  14  adds a small dummy pattern (for example, sub-resolution assist features (SRAF)) that is not resolved on the wafer at a plurality of types of positions. The line end setting unit  14  adds dummy patterns at positions acquired by expanding the line end setting pattern in the longitudinal direction.  FIG. 10  illustrates cases in which dummy patterns are set at positions separated by a first distance  28 A and a second distance  28 B, which are mutually difference distances. 
     A dummy pattern  29 A is arranged at a position separated from the line end of line end setting pattern by the first distance  28 A in the longitudinal direction of the line end setting pattern, and a dummy pattern  29 B is arranged at a position separated from the line end of line end setting pattern by the second distance  28 B in the longitudinal direction of the line end setting pattern. 
     When the dummy pattern  29 A is added to the line end setting pattern at the position separated by the first distance  28 A, the line end of the line end setting pattern becomes a line end  24 A of the dummy pattern  29 A. When drawing shots are set by using this line end  24 A as the reference, drawing data  64 A having a separation position  74 A is formed. 
     Similarly, when the dummy pattern  29 B is added to the line end setting pattern at the position separated by the second distance  28 B, the line end of the line end setting pattern becomes a line end  24 B of the dummy pattern  29 B. When drawing shots are set by using this line end  24 B as the reference, drawing data  64 B having a separation position  74 B is formed. 
     In addition, when a dummy pattern is not added to the line end setting pattern, the line end of the line end setting pattern is not moved and is the line end  24 C that is the line end of the line end setting pattern. When drawing shots are set by using the line end  24 C as the reference, drawing data  64 C having a separation position  74 C is formed. 
     Furthermore, the protruded patterns  26 A to  26 C may be removed after the generation of the drawing data  62 A to  62 C and may be left to remain when there is no influence thereof on the on-wafer pattern. In addition, in a case where the line end setting pattern is expanded or contracted, after the generation of the drawing data  63 A to  63 C, the expansion/contraction may be restored to the original state or may be remained to be expanded or contracted when there is no influence thereof on the on-wafer pattern. Furthermore, the dummy patterns  29 A and  29 B may be removed after the generation of the drawing data  64 A to  64 C and may be left to remain when there is no influence thereof on the on-wafer pattern. 
     Next, a process of setting a plurality of separation positions for one piece of drawing data will be described.  FIG. 11  is a diagram that illustrates the process of setting a plurality of separation positions for the pattern data. Here, a case will be described in which the size of the line end setting pattern in the longitudinal direction is pattern length h, and the length of a side out of sides of a drawing shot in the same direction as the direction of the pattern length h is size b. 
     The line end setting unit  14  sets a pattern satisfying a division condition as a line end setting pattern. For example, the division condition is for a pattern satisfying that the pattern length h of the line end setting pattern is a predetermined value or more, and the size (pattern width W) in the direction of a short side is a predetermined value or less. The line end setting unit  14 , for example, sets a pattern having a pattern length h that is the size b of one side of a drawing shot or more and a pattern width W that is 1/10 of the size b of one side of the drawing shot or less as a line end setting pattern. When the line end setting unit  14  sets line ends at a plurality of positions for the line end setting pattern, the division area setting unit  15  performs the process of setting separation positions for each line end that has been set. 
     The division area setting unit  15 , for example, sets the position of the line end as a separation position of the first drawing shot. The line end, for example, is set to a position that is separated from one end portion of the pattern data  31  by distance a in the longitudinal direction, and a separation position P 1  of the first drawing shot is set at this position. 
     In addition, the division area setting unit  15  sets a position that is separated from the separation position P 1  of the first drawing shot by the size b of one side of the drawing shot in the longitudinal direction of the pattern data  31  as a separation position P 2  of a second drawing shot. 
     Similarly, the division area setting unit  15  sets a position that is separated from the separation position P 2  by b in the longitudinal direction of the pattern data  31  as a separation position P 3  of a third drawing shot. Subsequently, similarly, for the pattern data  31 , fourth and fifth separation positions (not illustrated in the figure) and an m-th (here, m is a natural number) separation position Pm are sequentially set. Then, when a remaining pattern length of the pattern data  31  for which a separation position has not been set is a predetermined value or less, the division area setting unit  15  ends the process of setting separation positions. In other words, when a remaining division pattern length is a predetermined value or less, the division area setting unit  15  does not perform final division. Here, the predetermined value is a value within an allowed range in which a drawing shot can be expanded for the size b of one side of the drawing shot. From this, a process of dividing a fine graphic is avoided. In addition, the pattern data  31 , as illustrated in  FIG. 11 , may be generated such that the end portion is in the inclination direction with respect to the longitudinal direction. 
     In the line end set at a position separated from one end portion in the longitudinal direction of the pattern data  31  by distance a, a plurality of types of distances a are set. For example, in a case where N types of distances a are set for the size b of one side of a drawing shot, the division area setting unit  15  sets N types of distances a by performing shifting by a distance acquired by equally dividing the size b by N. 
     For example, in a case where the length of one side of a drawing shot is 0.5 μm, and four types of distance a are set as the line end, the division area setting unit  15  sets four types of a=0 μm, a=1.25 μm, a=2.5 μm, and a=3.75 μm as the line end. Then, for each one of the four types of line ends, separation positions of the pattern data  31  are set. As a result, four types of drawing data acquired by shifting the division positions are generated. 
     In addition, the distance a is not limited to being set by performing shifting by each distance acquired by equally dividing the size b by N, and any distance may be set. For example, N types of random values within the size b are set, and the set random values may be set as the distances a. In such a case, when the length of one side of a drawing shot is 0.5 μm, N types of values less than 0.5 μm are set as the distances a. 
       FIG. 12  is a diagram that illustrates drawing data generated based on pattern data. As illustrated in the figure, the drawing data generating device  1  generates a plurality of types of drawing area data (drawing area data  82 A to  82 C) for the multiple exposure setting area  5  including a plurality of pieces of pattern data  31 . The drawing area data  82 A is generated using drawing data  83 A separated at the first separation position, and the drawing area data  82 B is generated by using drawing data  83 B separated at the second separation position. In addition, the drawing area data  82 C is generated by using drawing data  83 C separated at the third separation position. In this way, the drawing data generating device  1  sets various separation positions at the pattern data  31 , thereby generating a plurality of types of drawing area data. 
       FIG. 13  is a diagram that illustrates the shape of a drawing pattern formed on a substrate by using a plurality of types of drawing data. For example, in a case where one type of drawing data  32 C is generated for the pattern data  31 , and multiple exposures are performed using the one type of drawing data  32 C for the substrate, thickening or thinning of an on-substrate pattern  46  may easily occur near the separation position of the drawing data  32 C. The reason for this is that a joint portion of drawing shots overlaps each other at the same position, and thus, a variation in the size at the joint portion of drawing shots remains to be highlighted even after the multiple exposures. 
     On the other hand, as in this embodiment, in a case where a plurality of types (here, two types) of drawing data  32 A and  32 B are generated for the pattern data  31 , and multiple exposures are performed using the drawing data  32 A and  32 B for the substrate, it is possible to form an on-substrate pattern  45  having a stable size also near the separation position of the drawing data  32 A and  32 B. The reason for this is that multiple exposures are performed using a plurality of types of drawing data, and thus, joint portions deviate for each exposure of the multiple exposures. Accordingly, compared to a case where there is no deviation in joint portions of drawing shots, a variation in the size of the on-substrate pattern decreases. In other words, by shifting the connection positions of drawing shots, a variation in the size at the connection positions of drawing shots decreases. 
     After the drawing data is generated using the pattern data  31 , an on-substrate pattern is formed on the substrate by using the drawing data. For example, in a case where the substrate is a template, a template pattern corresponding to the drawing data is drawn on the template. From this, a template having a pattern corresponding to the drawing data is produced. 
     When an on-substrate pattern is drawn on a substrate such as a template, the substrate is coated with a resist. Then, by performing EB drawing of a pattern corresponding to the drawing data from the upper side of the resist, a pattern corresponding to the drawing data is formed on the substrate. 
     Thereafter, a semiconductor device (semiconductor integrated circuit) is manufactured by using the produced template. More specifically, after a processing film is formed on a wafer, the processing film is coated with a resist. Then, an imprinting device performs an imprinting process using the template for the wafer coated with the resist. From this, a resist pattern is formed on the wafer. 
     On the other hand, in a case where the substrate is a photomask (mask blanks), a mask pattern corresponding to drawing data is drawn on the photomask. From this, the photomask corresponding to the drawing data is produced. In this case, a semiconductor device is also produced by using the produced photomask. More specifically, an exposure device performs an exposure process using the photomask for the wafer coated with the resist. Thereafter, by developing the wafer, a resist pattern is formed on the wafer. 
     After the resist pattern is formed on the wafer, a lower layer side (processing film) of the wafer is etched using the resist pattern as a mask. From this, an on-wafer pattern corresponding to the resist pattern is formed on the wafer. In addition, in a case where the substrate is a wafer, an on-wafer pattern corresponding to the drawing data is directly drawn on the wafer. 
     When a semiconductor device is manufactured, the generation of the pattern data  31 , the generation of a plurality of types of drawing data, the formation of a drawing pattern on the substrate through multiple exposures, a lithography process for the wafer using the substrate, the etching process of the processing film, which have been described above, and the like are repeated for each layer. 
     In addition, the setting of separation positions is not limited to a case in which separation positions located at the same position for each pattern within each pattern group are set, and separation positions that are different for each pattern may be set.  FIG. 14  is a diagram that illustrates drawing data in a case where separation positions that are different for each pattern are set. 
     The drawing data  81 P,  81 Q, and  81 R are drawing data in a case where the same separation positions are set for each pattern within the pattern group, and the drawing data  85 P,  85 Q, and  85 R are drawing data in a case where separation positions that are different for each pattern are set. 
     When the separation positions are set for a pattern group configured by patterns having the same shape, each pattern is separated at the same separation position. In other words, a separation position  82 P of the drawing data  81 P, a separation position  82 Q of the drawing data  81 Q, and a separation position  82 R of the drawing data  81 R are set to the same position within the pattern. Similarly, a separation position  83 P of the drawing data  81 P, a separation position  83 Q of the drawing data  81 Q, and a separation position  83 R of the drawing data  81 R are set to the same position within the pattern. 
     When separation positions different for each pattern are set, a separation position  86 P of the drawing data  85 P, a separation position  86 Q of the drawing data  85 Q, and a separation position  86 R of the drawing data  85 R are set to different positions within the pattern. Similarly, a separation position  87 P of the drawing data  85 P, a separation position  87 Q of the drawing data  85 Q, and a separation position  87 R of the drawing data  85 R are set to different positions within the pattern. In addition, a separation position  88 P of the drawing data  85 P and a separation position  88 R of the drawing data  85 R are set to different positions within the pattern. When separation positions different for each pattern are set, as above, joint portions of drawing shots for adjacent patterns are not adjacent to each other. Since there is a discrepancy between joint portions of drawing shots of patterns adjacent to each other, it is possible to prevent the formation of a short circuit (unintended pattern bonding) occurring between adjacent patterns. 
     Next, the hardware configuration of the drawing data generating device  1  will be described.  FIG. 15  is a diagram that illustrates the hardware configuration of the drawing data generating device. The drawing data generating device  1  includes a central processing unit (CPU)  91 , a read only memory (ROM)  92 , a random access memory (RAM)  93 , a display unit  94 , and an input unit  95 . In the drawing data generating device  1 , the CPU  91 , the ROM  92 , the RAM  93 , the display unit  94 , and the input unit  95  are interconnected through a bus line. 
     The CPU  91  generates drawing data using a drawing data generating program  97  that is a computer program. The drawing data generating program  97  is a computer program product having a computer-readable recording medium including a plurality of instructions, which can be executed by a computer, used for generating drawing data. The drawing data generating program  97  executes generation of drawing data in accordance with the plurality of instructions on a computer. 
     The display unit  94  is a display device such as a liquid crystal monitor and displays the pattern data  31 , a plurality of types of drawing data, the multiple exposure setting area  5 , and the like based on an instruction supplied from the CPU  91 . The input unit  95  is configured to include a mouse and a keyboard and receives instruction information (a parameter that is necessary for generation of drawing data and the like) that is externally input from a user as an input. The instruction information input to the input unit  95  is transmitted to the CPU  91 . 
     The drawing data generating program  97  is stored in the ROM  92  and is loaded into the RAM  93  through a bus line.  FIG. 15  illustrates a state in which a drawing data generating program  97  is loaded into the RAM  93 . 
     The CPU  91  executes the drawing data generating program  97  that has been loaded into the RAM  93 . More specifically, in the drawing data generating device  1 , the CPU  91  reads the drawing data generating program  97  from the inside of the ROM  92 , expands the program into a program storage area arranged inside the RAM  93 , and executes various processes in accordance with an instruction input transmitted from the input unit  95  by a user. The CPU  91  temporarily stores various kinds of data generated when the various processes are performed in a data storage area that is formed inside the RAM  93 . 
     The drawing data generating program  97  executed by the drawing data generating device  1  has a modular configuration including a target area extracting unit  13 , a line end setting unit  14 , and a division area setting unit  15 , and these are loaded into a main memory device and are generated on the main memory device. 
     In this embodiment, although a case has been described in which a plurality of types of drawing data are generated using the pattern data  31 , a plurality of types of drawing data may be generated based on one piece of drawing data. In such a case, by shifting the separation position of drawing data that is generated first to various positions, the other new drawing data is generated. In addition, the drawing data that is generated first may be generated using any method. 
     In addition, in an area other than the multiple exposure setting area, drawing data may be generated by the drawing data generating device  1  or may be generated by another device. In the area other than the multiple exposure setting area, for example, an on-substrate pattern corresponding to the drawing data is drawn on the substrate by one exposure. 
     According to the embodiment as above, a plurality of types of drawing data having different separation positions of drawing shots are generated, and multiple exposures are performed using the generated plurality of types of drawing data, and accordingly, it is possible to decrease a size variation in the joint portions of drawing shots. Accordingly, an on-substrate pattern having a desired size can be formed. 
     In addition, since a plurality of types of drawing data are generated for the multiple exposure setting area, it can be avoided that the data amount of data used when the drawing data is generated or a processing time required for generating the drawing data becomes large. 
     Furthermore, since a plurality of types of line ends are set by performing shifting by each distance acquired by equally dividing the size b of one side of the drawing shot by N, the separation positions of drawing shots can be uniformly arranged on the pattern data  31 . Accordingly, the on-substrate data corresponding to the pattern data  31  can be drawn on the substrate in a stable size. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.