Patent Number: 
Section: description

Now, Embodiment 1 of the invention will be described with reference to the accompanying drawings. FIG. 1 is a process flowchart of a lithography pattern data generation method of Embodiment 1, and FIGS. 2(a) through 2(c) show the layout of design data in respective procedures in the lithography pattern data generation method of this embodiment. First, in a design data preparing process ST01 of FIG. 1, plural design data 11 through 16 corresponding to design patterns to be formed on a substrate are prepared as is shown in FIG. 2(a). These design data 11 through 16 are arranged in a data arranging area 10 correspondingly to a design pattern formation area. Next, in a first area dividing process ST02 of FIG. 1, the data arranging area 10 is divided into a first stripe area group 61 including three stripe areas 61a through 61c. Each of the stripe areas 61a through 61c has a width corresponding to, for example, that of a partial exposure area of the exposure beam of an electron beam lithography system, and hence, the width is controlled in accordance with the maximum deflection width of a primary deflection device of the electron beam lithography system. Herein, the first stripe area group 61 has a stripe width of 5 mm. Then, in a first data group extracting process ST03 of FIG. 1, design data each falling within any of the stripe areas 61a through 61c, namely, design data not extending over any boundary of the stripe areas 61a through 61c, are extracted from the plural design data 11 through 16 as a first design data group. Accordingly, in FIG. 2(b), since each of the design data 11 through 15 falls within any of the stripe areas 61a through 61c, the first design data group consists of the design data 11 through 15. Subsequently, first lithography pattern data 1 of each stripe area of the first stripe area group 61 are generated from the design data 11 through 15 belonging to the first design data group. Next, in a second data group extracting process ST04 of FIG. 1, design data each extending over plural stripe areas of the first stripe area group 61 are extracted as a second design data group. In FIG. 2(b), since the design data 16 extends over the adjacent stripe areas 61a and 61b, the second design data group consists of the design data 16. For the sake of explanation, the design data 11 through 16 are herein subjected to the two extracting processes, that is, the first design data group extracting process ST03 and the second design data group extracting process ST04, but needless to say, when one of the first and second design data groups is extracted from the design data 11 through 16, the other data group is naturally determined. Next, in a second area dividing process ST05 of FIG. 1, the data arranging area 10 is divided, as is shown in FIG. 2(c), to obtain a second stripe area 62, which can cover the design data 16 and is differently divided from the first stripe are a group 61. A second lithography pattern data 2 is generated from the design data 16 falling within the second stripe area 62. Herein, the width of the second stripe area 62 can be the same as or different from the stripe width of the first stripe area group 61. Thus, among the design data 11 through 16, the design data 16 extending over the boundary in the first stripe area group 61 falls within the second stripe area 62 different from the first stripe area group 61 in this embodiment. Therefore, the second lithography pattern data 2 generated from the design data 16 is free from a connection error. As a result, an exposed pattern obtained based on the second lithography pattern data 2 can be improved in the accuracy. Also, the exposure beam of charged particles is used as an electron beam in this embodiment, but the generation of lithography pattern data does not depend upon the kind of charged particles. Specifically, the invention is effective in generating lithography pattern data when the drawing (exposure) area is smaller than a design pattern formation area and hence the lithography pattern data corresponding to design patterns should be divided into plural drawing areas. Furthermore, it is assumed in this embodiment that the lithography pattern data are generated for drawing design patterns on a semiconductor substrate of a semiconductor integrated circuit device, but the invention is not limited to this application but is effectively applicable to a mask pattern of an exposure mask used in fabrication of a semiconductor integrated circuit device, a design pattern on a display substrate of a liquid crystal display device and a design pattern on a magnetic head of a thin film magnetic head device. Now, Modification 1 of Embodiment 1 of the invention will be described with reference to the accompanying drawings. FIGS. 3(a) through 3(c) show the layout of design data in respective procedures in a lithography pattern data generation method of this modification. In FIGS. 3(a) through 3(c), like reference numerals are used to refer to like elements used in FIGS. 2(a) through 2(c), so as to omit the description. As is shown in FIG. 3(a), a design data 17 most of which falls within the stripe area 61c of the first stripe area group 61 has a tip portion extending over the stripe area 61b and the stripe area 61c.  As a characteristic of this modification, in the first design data group extracting process ST03 of FIG. 1, each stripe area of the first stripe area group 61 is enlarged by a predetermined width merely in the extraction, so as to extract the first design data group by using the stripe areas 61a through 61c each with the enlarged width. In FIG. 3(a), the enlarged predetermined width is indicated as an extraction width 61d, which is set to, for example, approximately 0.5 xcexcm. In this manner, the design data 17 can be determined to be covered by the stripe area 61c in the data extraction of the first design data group extracting process ST03 as is shown in FIG. 3(b), and hence is extracted as the first design data group. Although the maximum deflection area of the primary deflection device is assumed as 5 mm, the primary deflection device of a general electron beam lithography system has a deflection width having a margin of several microns. Therefore, even when an exposed pattern protrudes to the stripe area 61b as in the design data 17 of FIG. 3(b), the pattern can be drawn. In this manner, in addition to the characteristic of Embodiment 1, the number of design data belonging to the first design data group is increased and the number of design data belonging to the second design data group is decreased in this modification. Therefore, in the case where the process for dividing the area into stripe areas is repeatedly conducted, the repeated processes can be easily converged. Although the extraction width 61d is set to 0.5 xcexcm in this modification, an appropriate value can be selected depending upon the used electron beam lithography system. Modification 2 of Embodiment 1 will now be described with reference to the accompanying drawings. FIGS. 4(a) through 4(c) show the layout of design data in respective procedures in a lithography pattern data generation method of this modification. In FIGS. 4(a) through 4(c), like reference numerals are used to refer to like elements used in FIGS. 2(a) through 2(c), so as to omit the description. As is shown in FIG. 4(a), among plural design data arranged on the data arranging area 10, design data 16 and 18 extend over the boundaries of the adjacent stripe areas. Also, a portion of the design data 16 crossing the boundary of the stripe areas is assumed to be in the size of 0.4 xcexcm, and a portion of the design data 18 crossing the boundary is assumed to be in the size of 1.2 xcexcm. As a characteristic of this modification, in the first design data group extracting process ST03 of FIG. 1, among design data each extending over any boundary of the adjacent stripe areas, one having a portion crossing the boundary in the size of 1.0 xcexcm or more is extracted as the first design data group, and one having a portion crossing the boundary in the size smaller than 1.0 xcexcm is extracted as the second design data group. Although a connection error caused in adjacently connecting divided data corresponds to approximately 50 nm, the design data 18 has the crossing portion in the size of 1 xcexcm or more, and hence is minimally affected by the connection error but can attain sufficient accuracy in the connected exposed pattern. Therefore, the design data 18 can be included in the first design data group. Accordingly, in addition to the characteristic of Embodiment 1, the number of design data belonging to the second design data group can be decreased. Therefore, in the case where the process for dividing the area into stripe areas is repeatedly conducted, the repeated processes can be easily converged. Although merely a design data having a portion crossing the boundary of the stripe areas in the size smaller than 1 xcexcm is extracted as the second design data group in this modification, the range of the size is preferable to be optimized depending upon the accuracy of the lithography system and the process conditions. Also, when the size of the portion crossing the boundary of the stripe areas accords with the predetermined value, for example, 1 xcexcm, the corresponding design data is included in the first design data group in this embodiment, but it can be included in the second design data group. Embodiment 2 of the invention will now be described with reference to the accompanying drawings. FIG. 5 is a process flowchart of a lithography pattern data generation method of Embodiment 2, and FIGS. 6(a) through 6(e) show the layout of design data in respective procedures in the lithography pattern data generation method of Embodiment 2. First, in a design data preparing process ST11 of FIG. 5, plural design data 21 through 26 corresponding to design patterns to be formed on a substrate are prepared on a data arranging area 10 as is shown in FIG. 6(a). Next, in a first area dividing process ST12 of FIG. 5, the data arranging area 10 is divided into a first stripe area group 61 including stripe areas 61a through 61c each with a width of approximately 5 mm. Then, in a first data group extracting process ST13 of FIG. 5, design data each falling within any of the stripe areas are extracted from the plural design data as a first design data group. Accordingly, in FIG. 6(b), since each of the design data 21 through 23 falls within any of the stripe areas 61a and 61c, the first design data group consists of the design data 21 through 23. Subsequently, first lithography pattern data 1 of each stripe area of the first stripe area group 61 are generated from the design data 21 through 23 belonging to the first design data group. Next, in a second data group extracting process ST14 of FIG. 5, design data each extending over the plural stripe areas of the first stripe area group 61 are extracted as a second design data group. As is shown in FIG. 6(a), the design data 24 extends over the adjacent stripe areas 61a and 61b, and the design data 25 and 26 extend over the adjacent stripe areas 61b and 61c. Therefore, the second design data group consists of the design data 24 through 26. Then, in a second area dividing process ST15 of FIG. 5, as is shown in FIG. 6(c), the data arranging area 10 is divided into a second stripe area group 62 including stripe areas 62a and 62b, which cover the design data 24 and 25, respectively and are differently divided from the first stripe area group 61. Next, in a third data group extracting process ST16 of FIG. 5, design data each falling within any of the stripe areas of the second stripe area group 62 are extracted from the second design data group as a third design data group. In FIG. 6(d), the design data 24 and 25 fall within the stripe areas 62a and 62b, respectively, and hence the third design data group consists of the design data 24 and 25. Accordingly, second lithography pattern data 2 of each stripe area of the second stripe area group 62 are generated from the design data 24 and 25 belonging to the third design data group. Then, in a fourth data group extracting process ST17 of FIG. 5, design data each extending over adjacent stripe areas of the second stripe area group 62 are extracted as a fourth design data group. As is shown in FIG. 6(c), the design data 26 extends over the adjacent stripe areas 62a and 62b, and the fourth design data group consists of the design data 26. Next, in a third area dividing process ST18 of FIG. 5, the data arranging area 10 is divided to obtain a third stripe area 63 as is shown in FIG. 6(e), which covers the design data 26 belonging to the fourth design data group and is differently divided from the second stripe area group 62. Subsequently, in a fifth data group extracting process ST19 of FIG. 5, design data each falling within the third stripe area is extracted from the fourth design data group as a fifth design data group. In FIG. 6(e), the design data 26 falls within the third stripe area 63, and hence the fifth design data group consists of the design data 26. Accordingly, a third lithography pattern data 3 of the third stripe area 63 is generated from the design data 26 belonging to the fifth design data group. Then, in a sixth data group extracting process ST20 of FIG. 5, design data each extending over the boundary of the third stripe area (group) 63 are extracted as a sixth design data group, and fourth lithography pattern data of each stripe area of the third stripe area (group) 63 are generated from design data belonging to the extracted sixth design data group. However, in the exemplified layout shown in FIG. 6(e), there is no design data extending over the boundary of the third stripe area 63, and hence, the sixth design data group is not generated in this case. In this embodiment, merely the basic concept of the invention is described, and the elements of the fourth and fifth design data groups are the design data 26 alone. The number of design data used in an actual semiconductor device is huge, and therefore, it seems that there remain a large number of design data extending over the boundaries of the adjacent stripe areas after the three dividing processes for obtaining the third stripe area (group) 63. Accordingly, actual generation of lithography pattern data is carried out as the data process using a computer, and the dividing process is repeatedly conducted with the dividing positions of the stripe area groups successively changing so as to decrease the number of design data extending over adjacent stripe areas, preferably until there is no design data extending over adjacent stripe areas. However, when the number of times of repeating the dividing process is too large, the through-put time can be largely increased depending upon the scale of the design data, and therefore, the number of times of repeating the dividing process should be naturally controlled. Also in this embodiment, in the first data group extracting process ST13, the third data group extracting process ST16 or the fifth data group extracting process ST19, each stripe area can be provided with an extraction width of 0.5 xcexcm as in Modification 1 of Embodiment 1. Furthermore, in the first data group extracting process ST13, the third data group extracting process ST16 or the fifth data group extracting process ST19, a design data having a portion crossing a boundary of stripe areas in the size exceeding a predetermined value-can be extracted as the first design data group, the third design data group or the fifth design data group as in Modification 2 of Embodiment 1. In this manner, in this embodiment, the data arranging area 10 is divided by using one stripe area group corresponding to a partial exposure area controlled by the deflectable width of the exposure beam. Then, merely design data extending over the adjacent stripe areas are extracted, and the data arranging area 10 is divided again by using another stripe area group so that at least one of the design data extending over the stripe areas can be made not to extend over new stripe areas. Such a dividing process is repeated until none of the prepared plural design data extends over the stripe areas, so that the resultant lithography pattern data can be free from a connection error. Accordingly, exposed patterns drawn on the basis of the lithography pattern data can be remarkably improved in the accuracy. Modification 1 of Embodiment 2 will now be described with reference to the accompanying drawings. FIGS. 7(a) through 7(d) and 8(a) through 8(c) show the layout of design data in respective procedures in a lithography pattern data generation method of this modification. In FIGS. 7(a) through 7(d) and 8(a) through 8(c), like reference numerals are used to refer to like elements used in FIGS. 6(a) through 6(e), so as to omit the description. In the data generation of this modification, prepared design data includes a design data 27 having a size (length) along the widthwise direction of a stripe area larger than the width of the stripe area and including a wide portion 27a as is shown in FIG. 7(a). First, as is shown in FIG. 7(b), the first design data group consists of the design data 21 through 23, and the second design data group consists of the design data 24 through 28. Then, as is shown in FIG. 7(c), since the data arranging area 10 is divided into the second stripe area group 62 so that each of the design data 24 and 25 belonging to the second design data group falls within one stripe area, the fourth design data group consists of the design data 27 and 28 as is shown in FIG. 7(d). Next, as is shown in FIGS. 8(a) and 8(b), when the data arranging area 10 is divided so that the design data 28 belonging to the fourth design data group can fall within one stripe area of the third stripe area group 63, the sixth design data group consists of the design data 27 because it extends over the boundary of the stripe areas. Then, as is shown in FIG. 8(c), a design data having a size, along the widthwise direction of the stripe area, larger than the width of the stripe area is extracted from the design data belonging to the sixth design data group. The design data having a size, along the widthwise direction of the stripe area, larger than the width of the stripe area can never fall within one stripe area, and hence, the dividing process of the data arranging area 10 cannot be converged no matter how many times it is repeated. Accordingly, in this modification, the design data 27 is extracted, which has the wide portion 27a with a length, perpendicular to the exposure direction corresponding to the extending direction of the stripe area, smaller than the width of the stripe area and a width scarcely causing a connection error, for example, of 1 xcexcm or more. Subsequently, the data arranging area 10 is divided into a fourth stripe area group 64 including stripe areas 64a and 64b so that the boundary therebetween can be positioned on the wide portion 27a of the design data 27. When the data arranging area 10 is thus divided so that the wide portion 27a of the design data 27 with a width exceeding the predetermined value can be positioned on the boundary in the fourth stripe area group 64, a connection error is minimally caused in the resultant exposed pattern even when it is obtained from the design data divided between the stripe areas. Modification 2 of Embodiment 2 will now be described with reference to the accompanying drawings. FIGS. 9(a) through 9(d) and 10(a) through 10(c) show the layout of design data in respective procedures in a lithography pattern data generation method of this modification. In FIGS. 9(a) through 9(d) and 10(a) through 10(c), like reference numerals are used to refer to like elements used in FIGS. 7(a) through 7(d) and 8(a) through 8(c), so as to omit the description. In Modification 1 of Embodiment 2, as is shown in FIGS. 8(b) and 8(c), after the design data 27 having the size, along the widthwise direction of the stripe area, larger than the width of the stripe area is extracted from the design data belonging to the sixth design data group, since the extracted design data 27 has the wide portion 27a with a width exceeding the predetermined value, the data arranging area 10 is divided into the fourth stripe area group 64 so that the wide portion 27a can be positioned on the boundary. In this modification, as is shown in FIG. 10(c), a design data 29 having the size, along the widthwise direction of the stripe area, larger than the width of the stripe area does not have a wide portion as that of the design data 27 of Modification 1. Therefore, an auxiliary pattern data 30 for preventing deformation of an exposed pattern is positively added onto a portion of the design data 29 crossing the boundary in the fourth stripe area group 64. In this manner, although the design data 29 does not have a wide portion as that in Modification 1, a connection error is scarcely caused in the resultant exposed pattern. Furthermore, as a third modification, the design data 29 extending over the plural stripe areas can be subjected to multiple exposure used in writing a photomask. When the multiple exposure is conducted on the design data 29 extending over the boundary between the stripe areas, a connection error can be avoided. In this manner, a highly accurate exposed pattern can be obtained by adding the auxiliary pattern data 30 to the design data 29 extending over the boundary of the stripe areas or by conducting the multiple exposure. In addition, the addition of the auxiliary pattern data or the multiple exposure is carried out on the specified design data alone, and hence, the degradation of the through-put can be prevented. Embodiment 3 of the invention will now be described with reference to the accompanying drawings. FIGS. 11(a) through 11(e) show the layout of design data in respective procedures in a lithography pattern data generation method of Embodiment 3. This embodiment is characterized by classifying prepared design data in accordance with a pattern width. First, as is shown in FIG. 11(a), plural design data 31 through 36 are arranged on a design data arranging area 10. Among these design data, the design data 32 and 35 are in the shape of a composite figure formed by connecting a figure with a comparatively large width and another figure with a comparatively small width. Next, as is shown in FIG. 11(b), the design data are classified into a first design data group with a pattern width exceeding, for example, 1 xcexcm and a second design data group with a pattern width of 1 xcexcm or less. Furthermore, the design data 32 and 35 are herein divided into figure units. Accordingly, the first design data group consists of the design data 31, 32A, 34, 35A and 36, and the second design data group consists of the design data 32B, 33 and 35B. Then, as is shown in FIG. 11(c), the data arranging area 10 where the first design data group is arranged is divided into a first stripe area group 61 including stripe areas 61a through 61c each with a width of approximately 5 mm. First exposed patterns of each stripe area of the first stripe area group 61 are generated from the design data 31, 32A, 34, 35A and 36 belonging to the first design data group. At this point, the design data 36 extends over the boundary between the stripe areas 61b and 61c, but a connection error is scarcely caused because it has a pattern width larger than 1 xcexcm. Similarly, the data arranging area 10 where the second design data group is arranged is divided into the first stripe area group 61 including the stripe areas 61a and 61b.  Next, as is shown in FIG. 11(d), the design data 32B and 33 each falling within any of the stripe areas of the first stripe area group 61 are extracted as a third design data group, and the design data 35B extending over the boundary is extracted as a fourth design data group. Subsequently, second lithography pattern data of each stripe area of the first stripe area group 61 are generated from the design data 32B and 33 belonging to the third design data group. Then, as is shown in FIG. 11(e), the data arranging area 10 is divided to obtain a second stripe area 62 which covers the design data 35B and is differently divided from the first stripe area group 61. Subsequently, a third lithography pattern data of the second stripe area 62 is generated from the design data 35B belonging to the fourth design data group. At this point, the width of the second stripe area 62 can be the same as or different from the stripe width of the first stripe area group 61. In this manner, the design data 31 through 36 are classified in accordance with a pattern width in this embodiment before dividing the data arranging area 10 into the first stripe area group 61. Accordingly, the number of design data having a pattern width smaller than the predetermined value and extending over the boundary of the stripe areas can be largely decreased. As a result, there is less fear of a connection error caused in exposed patterns, and when the process for dividing the area into the stripe areas is repeatedly conducted, the repeated processes can be more rapidly converged, resulting in improving the through-put. Although the design data 32 and 35 are divided into figure units in this embodiment, the process for dividing a design data is not always necessary. Embodiment 4 of the invention will now be described with reference to the accompanying drawings. FIG. 12 shows the functional structure of an electron beam lithography system of Embodiment 4. As is shown in FIG. 12, respective units of the electron beam lithography system 90 of this embodiment are operated under control of a control CPU 91. A lithography pattern data generation unit 92 functions in accordance with the lithography pattern data generation method of this invention, namely, a software program for realizing the lithography pattern data generation method described in any of Embodiments 1 through 3. The lithography pattern data generation unit 92 includes an area dividing part for dividing a data arranging area corresponding to a pattern formation area on a substrate into plural partial exposure areas each in the shape of a stripe corresponding to the deflection width of an exposure beam; a data group extracting part for extracting, from design data stored in a data storage unit 93, design data each falling within any of the plural partial exposure areas as a first design data group and extracting design data each extending over two or more of the partial exposure areas as a second design data group; and a data generating part for generating lithography pattern data of the respective partial exposure areas from the design data belonging to the first design data group and the second design data group. A reference numeral 100 denotes an electron optical lens barrel, in which an electron gun 104 is disposed in the upper portion and a movable stage for supporting a substrate to be exposed is disposed in a position for receiving an electron beam. The structure of the electron optical lens barrel 100 will be described in detail below. A lithography control unit 94 serving as charged particle controlling means, substrate position controlling means and beam shape controlling means controls blanking of the electron gun 104 by adjusting its output state on the basis of the lithography pattern data generated by the lithography pattern data generation unit 92. In addition, the lithography control unit 94 instructs a stage position control unit 95 to adjust the relative position of the movable stage for supporting the substrate against the electron gun 104, and instructs a deflection control unit 96 to control the shape of the electron beam by adjusting the deflection state of the electron beam. A mechanism control unit 97 adjusts lithography environments, for example, adjusts the pressure in the electron optical lens barrel 100. FIG. 13 schematically shows the structure of the electron optical lens barrel 100 of this embodiment. As is shown in FIG. 13, above a substrate 102 supported by a movable stage 101 serving as substrate supporting means is disposed an electron gun 104, serving as charged particle producing means, for emitting an electron beam 103 toward the substrate 102. Between the movable stage 101 and the electron gun 104, a first aperture 105, serving as beam shaping means, having a first opening 105a in a square shape; a selective deflection device 106, serving as beam shaping means, for appropriately deflecting the electron beam 103 having passed through the first opening 105a; a second aperture 107, serving as beam shaping means, having a second opening 107a in a square shape; and a reducing lens 108 for reducing an exposure beam with a square section, that is, the electron beam having passed through the second opening 107a are disposed in this order in the direction from the electron gun 104 to the movable stage 101. On the inside of the reducing lens 108, a primary deflection device 109A for deflecting the exposure beam is disposed, and on the inside of the primary deflection device 109A, a secondary deflection device 109B and a tertiary deflection device 109C are disposed in the upper portion and the lower portion, respectively. The operation of the electron lithography system having the aforementioned structure will now be simply described. First, as is shown in FIG. 13, the substrate 102 coated with a photosensitive material sensitive to the electron beam is supported by the movable stage 101. Next, the electron gun 104 supplied with an acceleration voltage of approximately 50 kV emits the electron beam (exposure beam). The emitted electron beam 103 is shaped to have a square section by the first opening 105a of the first aperture 105. The electron beam 103 shaped into a square section is deflected by the selective deflection device 106 before reaching the second opening 107a, so that the electron beam 103 passing through the second opening 107a can be shaped to have a rectangular section. The thus shaped electron beam 103 is allowed to irradiate a predetermined area on the substrate 102 by the deflection devices 109A, 109B and 109C, so as to successively draw the exposed patterns in accordance with the design data. Since the deflection devices are thus provided in plural stages, higher deflection accuracy is attained. Now, a lithography pattern fabrication method using the electron beam lithography system with the aforementioned structure will be described. FIGS. 14(a) through 14(d) show the layout of exposed patterns in respective procedures in the lithography pattern fabrication method of this embodiment. In a memory space of the data storage unit 93 of FIG. 12, a data arranging area 10 corresponding to an exposure area on a substrate is formed as is shown in FIG. 14(a), and plural design data 41A through 46A corresponding to design patterns to be formed on the substrate are prepared on the data arranging area 10. The design data 41A through 46A are herein in the same positions and in the same shapes as the design data described in Embodiment 2. First, lithography pattern data are generated based on the design data 41A through 46A. At this point, the lithography pattern data are assumed in this embodiment to be generated by the generation method of Embodiment 2. Accordingly, the first design data group consists of the design data 41A, 42A and 43A, and the first lithography pattern data are generated from the first design data group. The third design data group consists of the design data 44A and 45A, and the second lithography pattern data are generated from the third design data group. The fourth design data group consists of the design data 46A, and the third lithography pattern data is generated from the fourth design data group. The thus generated first through third lithography pattern data are stored in the data storage unit 93. Next, the first lithography pattern data stored in the data storage unit 93 are drawn as is shown in FIG. 14(b). Specifically, lithography pattern data 41B through 41C corresponding to the design data 41A through 43A each falling within any of the stripe areas 61a through 61c of the first stripe area group 61, each in the shape of a stripe with a width of approximately 5 mm, are drawn on a pattern formation area 70 on the substrate successively in respective areas 71a, 71b and 71c of a first partial exposure area group 71. Then, the second lithography pattern data stored in the data storage unit 93 are drawn as is shown in FIG. 14(c). Specifically, lithography pattern data 44B and 45B corresponding to the design data 44A and 45A each falling within any of the stripe areas 62a and 62b of the second stripe area group 62 are drawn on the pattern formation area 70 on the substrate successively in respective areas 72a and 72b of a second partial exposure area group 72. Next, the third lithography pattern data stored in the data storage unit 93 is drawn as is shown in FIG. 14(d). Specifically, a lithography pattern data 46B corresponding to the design data 46A falling within the third stripe area 63 is drawn on the pattern formation area 70 on the substrate in a third partial exposure area 73. Herein, the data arranging area 10 is assumed to be in the same size as the pattern formation area 70 for simplification, and hence, each stripe area for dividing the data arranging area 10 is assumed to have the same width as each partial exposure area for dividing the pattern formation area 70. An exposed pattern can be, however, generally reduced or enlarged with keeping the relative relationship in position and size between the design data and the exposed pattern. Although the first lithography pattern data, the second lithography pattern data and the third lithography pattern data are drawn in this order in this embodiment, but the order is not herein specified as far as all the lithography pattern data can be ultimately drawn on the substrate. Similarly, the lithography pattern data are drawn in each of the partial exposure area groups 71 and 72 successively in the rightward direction in this embodiment, but the direction is not herein specified. However, since the movable stage 101 of FIG. 13 should be moved in order to proceed the lithography process from one stripe area to another stripe area, the lithography pattern data can be more efficiently drawn in a manner that adjacent stripe areas are successively exposed. In the conventional lithography system and method, merely one dividing process is carried out for drawing all the design data. Therefore, one exposed pattern extends over plural partial exposure areas, and hence, the exposed pattern is divided. As a result, a connection error is easily caused in the lithography. However, the number of exposed patterns extending over adjacent partial exposure areas can be decreased in this embodiment, resulting in reducing connection errors. Accordingly, highly accurate exposed patterns can be obtained. Since the electron beam lithography system 90 of this embodiment is operated on the basis of lithography pattern data generated by the lithography pattern data generation unit 92 of FIG. 12, the following auxiliary functions described in Embodiments 1 through 3 and their modifications can be reflected in lithography pattern data to be generated: (1) To increase the number of data belonging to a design data group extracted at an earlier stage by providing each stripe area used for extracting the data group with a predetermined extraction width; (2) To increase the number of data belonging to a design data group extracted at an early stage by extracting, among design data extending over stripe areas, a data having a portion crossing the boundary of stripe areas in a predetermined size or larger as a design data group obtained at an earlier stage; (3) To repeat the process for dividing the data arranging area into stripe areas until none of design data extends over the stripe areas; (4) With respect to a design data which is unavoidably divided because it has a size, along the widthwise direction of a stripe area, larger than the width of the stripe area and which has a wide portion crossing the boundary of stripe areas in a predetermined size or larger, to set the boundary between the stripe areas on the wide portion; (5) With respect to a design data which is unavoidably divided because it has a size, along the widthwise direction of a stripe area, larger than the width of the stripe area, to add, onto a portion crossing the boundary, an auxiliary pattern data having a predetermined size or larger in the crossing portion; and (6) To conduct the multiple exposure on a design data which is unavoidably divided because it has a size, along the widthwise direction of a stripe area, larger than the width of the stripe area. The electron beam lithography system 90 of this embodiment uses an electron beam as the exposure beam, which can be replaced with an ion beam. Also, the width of each stripe area or each partial exposure area is set to approximately 5 mm in this embodiment, but the width can be appropriately set depending upon the electron gun 104, the conditions for controlling the electron gun and the design data. Furthermore, the stripe width of each stripe area group (or partial exposure area group) adopted for repeated division can be appropriately selected with respect to each strip area within a deflectable range of the exposure beam. Now, as a specific example of the effect (6) described above, Modification 1 of Embodiment 4 will be described with reference to the accompanying drawings. FIGS. 15(a) through 15(d) show the layout of exposed patterns in respective procedures in a lithography pattern fabrication method of this modification. In FIGS. 15(a) through 15(d), like reference numerals are used to refer to like elements shown in FIGS. 14(a) through 14(d), so as to omit the description. As is shown in FIG. 15(a), a design data 47A has a size, in a direction crossing the extending direction of a stripe area of the first stripe area group 61, larger than the width of the stripe area. Therefore, the design data 47A cannot fall within one stripe area but is unavoidably divided, and hence belongs to the fourth design data group. Accordingly, as is shown in FIG. 15(d), in drawing the third lithography pattern data obtained from the fourth design data group, a lithography pattern data 47B extending over partial exposure areas 73a and 73b of a third partial exposure area group 73 is subjected to the multiple exposure. As a result, a connection error is scarcely caused in the resultant pattern, and thus, the accuracy of the unavoidably divided exposed pattern can be improved. Furthermore, the multiple exposure is conducted merely on the lithography pattern data unavoidably divided, and hence, degradation in the through-put can be minimized. Embodiment 5 of the invention will now be described with reference to the accompanying drawings. FIG. 16 is a process flowchart of a lithography pattern data generation method of Embodiment 5, and FIGS. 17(a) through 17(c) show the layout of exposed patterns obtained in respective procedures in a lithography pattern fabrication method using the lithography pattern data generation method of this embodiment. First, in a design data preparing process ST21 of FIG. 16, plural design data 41A through 46A corresponding to design patterns to be formed on a substrate are prepared as shown in FIG. 17(a). The design data 41A through 46A are arranged on a data arranging area 10 correspondingly to a design pattern formation area. Next, in an area dividing process ST22 of FIG. 16, the data arranging area 10 is divided into a first stripe area group 61 including three stripe areas 61a through 61c.  Then, in a first data group extracting process ST23 of FIG. 16, design data each falling within any of the stripe areas 61a through 61c, namely, not extending over any of the boundaries of the stripe areas 61a through 61c, are extracted from the design data 41A through 46A as a first design data group. Subsequently, based on the design data 41A through 43A belonging to the first design data group, first lithography pattern data 41B through 43B of each of the stripe areas 61a through 61c are generated. Next, in a second data group extracting process ST24 of FIG. 16, design data each extending over the plural stripe areas of the first stripe area group 61 are extracted as a second design data group. Subsequently, based on the design data 44A through 46A belonging to the second design data group, second lithography pattern data 44B through 46B of each of the stripe areas 61a through 61c are generated. Then, the first lithography pattern data 41B through 43B thus generated are transferred onto a pattern formation area 70 as is shown in FIG. 17(b). Subsequently, the second lithography pattern data 44B through 46B thus generated are subjected to the multiple exposure so as to transfer them onto the pattern formation area 70 as is shown in FIG. 17(c). In this manner, merely the second lithography pattern data 44B through 46B extending over the stripe areas are subjected to the multiple exposure in this embodiment. Therefore, connection errors can be easily reduced. Also in this embodiment, the order of conducting the lithography process on the first lithography pattern data and the second lithography pattern data is not particularly specified. Wherein, in the first design data group extracting process ST23, as described in MODIFICATION 1 of EMBODIMENT 1 of the present invention, each stripe area of the fist stripe area group 61 may be enlarged by a predetermine width merely in the extraction. In each of the aforementioned embodiments, the countermeasure against connection errors between stripe areas mainly derived from primary deflection is described, but the invention can exhibit the same effect also on a connection error derived from secondary or tertiary deflection.