JP2010067808A - Drawing apparatus, drawing data conversion method, and drawing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drawing apparatus capable of reducing the number of bits per pixel and also reducing data size. <P>SOLUTION: The drawing apparatus 100 is characterized by including: a pattern partitioning section 46 that acquires pattern information including at least one of a plurality of pattern figure codes, an array flag, the number of arrays and an array pitch; an accumulation table forming section 50 that relates each pattern information to the number of use for each pattern information for each predetermined region; a Huffman tree forming section 52 that forms a Huffman tree, a Huffman table forming section 54 that forms a Huffman table that relates each pattern information to an encrypted binary variable length code, wherein a smaller numerical value is assigned to pattern information as the frequency of use increases; a format converting section 56 that converts data in a predetermined region defined as drawing data in a predetermined format using a variable length code, and a drawing section 150 that draws a plurality of patterns in a test piece based on the converted data in the predetermined region. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drawing apparatus, a drawing data conversion method, and a drawing method. For example, the present invention relates to a drawing apparatus for drawing a predetermined pattern on a sample using an electron beam, a drawing method, and a method for converting drawing data processed in the apparatus.

  Lithography technology, which is responsible for the progress of miniaturization of semiconductor devices, is an extremely important process for generating a pattern among semiconductor manufacturing processes. In recent years, with the high integration of LSI, circuit line widths required for semiconductor devices have been reduced year by year. In order to form a desired circuit pattern on these semiconductor devices, a highly accurate original pattern (also referred to as a reticle or a mask) is required. Here, the electron beam (electron beam) drawing technique has an essentially excellent resolution, and is used for producing a high-precision original pattern.

FIG. 19 is a conceptual diagram for explaining the operation of a conventional variable shaping type electron beam drawing apparatus.
The variable shaped electron beam (EB) drawing apparatus operates as follows. In the first aperture 410, a rectangular opening for forming the electron beam 330, for example, a rectangular opening 411 is formed. Further, the second aperture 420 is formed with a variable shaping opening 421 for shaping the electron beam 330 that has passed through the opening 411 into a desired rectangular shape. The electron beam 330 irradiated from the charged particle source 430 and passed through the opening 411 is deflected by a deflector. Then, it passes through a part of the variable shaping opening 421 and irradiates the sample 340 mounted on the stage. The stage continuously moves in a predetermined direction (for example, the X direction) during drawing. That is, a rectangular shape that can pass through both the opening 411 and the variable shaping opening 421 is drawn in the drawing region of the sample 340 mounted on the stage that moves continuously. A method of creating an arbitrary shape by passing both the opening 411 and the variable forming opening 421 is referred to as a variable forming method.

  In performing such electron beam drawing, first, a layout of a semiconductor integrated circuit is designed. Then, layout data (design data) in which the pattern layout is defined is generated. Then, the layout data is converted, and drawing data suitable for the electron beam drawing apparatus is generated. The drawing data is input to the drawing apparatus, and is generated as shot data for drawing after a plurality of data processing (see, for example, Patent Document 1). Then, drawing processing is performed according to the shot data. Here, in the drawing apparatus, the drawing data is expanded, and intermediate data before the shot data is generated is generated. The pattern data format used in the past has been designed to be compatible with all possible sizes, coordinates, figure types, and numbers. For this reason, in the conventional pattern data format, the number of bits corresponding to any of these has been prepared.

However, depending on the layout of the drawing data, there are cases where only a part of the number of bits prepared in the conventional pattern data format is used. For example, in a layout where the repetition of patterns having the same shape or the same size is overwhelmingly, there is a situation in which only a small number of bits among the number of bits secured in the conventional pattern data format is used. If only a few patterns have a small number of bits in one layout, it will not be affected so much, but with the recent pattern miniaturization and the increase in the number of patterns, the number of patterns that require a small number of bits increases. is doing. Therefore, when the number of such unused bits is accumulated, the number of bits corresponds to a data size that cannot be ignored for the throughput of the apparatus.
JP 2007-128933 A

  As described above, the pattern data format used in the past has been prepared with a number of bits that can correspond to all possible sizes, coordinates, graphic types, and numbers. For this reason, many bits are not used, and the number of unused bits corresponds to a data size that cannot be ignored for the throughput of the apparatus. Along with the recent miniaturization of patterns and the increase in the number of patterns, reduction of the number of used bits of data has been an issue as the reduction of data size is required. Furthermore, the drawing data itself input to the drawing apparatus is similarly provided with a number of bits that can correspond to all possible sizes, coordinates, figure types, and numbers of pattern data formats. For this reason, the time for transferring the drawing data to the drawing apparatus also becomes long, and the transfer time cannot be ignored for the throughput of the apparatus.

  In view of the above, an object of one embodiment of the present invention is to provide a drawing device and a drawing data conversion method that reduce the number of bits and the data size. It is another object of the present invention to provide a drawing apparatus and method that reduce the number of bits of drawing data to be input and reduce the transfer time.

The drawing device of one embodiment of the present invention includes:
A storage unit for storing drawing data;
An acquisition unit that acquires pattern information including at least one of a graphic code, an array flag, an array number, and an array pitch of a plurality of defined patterns based on drawing data;
A first table creation unit that creates a first table that associates each piece of pattern information with the number of uses of each piece of pattern information based on a plurality of pieces of acquired pattern information for each predetermined region;
A Huffman tree creation unit for creating a Huffman tree based on the first table;
Based on the Huffman tree, a second table is created in which each pattern information is associated with a binary variable-length code obtained by encrypting each pattern information so that the pattern information having a larger number of uses has a smaller value. The table creation part of
A conversion unit that converts data in a predetermined area defined in the drawing data in a predetermined format using a variable length code based on the second table;
A drawing unit that draws a plurality of patterns on the sample based on the converted data in the predetermined region;
It is provided with.

  With this configuration, in the second table, the binary variable length code has a smaller value as the pattern information is used more frequently. Smaller values require fewer bits. Then, data in a predetermined area is converted in a predetermined format using a variable length code. Therefore, the converted data in the predetermined area is defined by variable length codes for each pattern information. At this time, since the pattern information having a larger number of uses is defined with a smaller number of bits, the number of bits used for the converted data in the predetermined area can be reduced.

  Moreover, it is preferable that the converted data in the predetermined area includes data in which the variable length code of each pattern information is continuous.

A drawing apparatus according to another aspect of the present invention includes:
A drawing created with a binary variable-length code in which each pattern information is encrypted so that the data in a predetermined area has a smaller value as the pattern information of a plurality of defined patterns and the pattern information with a higher number of uses. A storage unit for storing data;
A restoration unit for restoring data in a predetermined area;
A drawing unit for drawing a plurality of patterns on the sample based on the restored data;
It is provided with.

  With this configuration, the pattern information that is used more frequently has a smaller binary variable length code. Smaller values require fewer bits. For this reason, the number of bits used for drawing data input to the drawing apparatus for data in a predetermined area is reduced.

The drawing data conversion method of one embodiment of the present invention includes:
Inputting drawing data; and
Acquiring pattern information including at least one of a graphic code, an array flag, the number of arrays, and an array pitch of a plurality of defined patterns based on drawing data;
Creating a first table that associates each piece of pattern information with the number of uses of each piece of pattern information based on a plurality of pieces of acquired pattern information for each predetermined region;
Creating a Huffman tree based on the first table;
Creating a second table based on the Huffman tree and associating each pattern information with a binary variable-length code obtained by encrypting each pattern information so that the pattern information having a larger number of uses has a smaller value; ,
Converting the data in a predetermined area defined in the drawing data in a predetermined format using a variable length code based on the second table;
Storing the converted data in the predetermined area;
It is provided with.

The drawing method of one embodiment of the present invention includes:
A drawing created with a binary variable-length code in which each pattern information is encrypted so that the data in a predetermined area has a smaller value as the pattern information of a plurality of defined patterns and the pattern information with a higher number of uses. Inputting data,
Restoring the data in a predetermined area;
Drawing a plurality of patterns on the sample based on the restored data;
It is provided with.

  According to the present invention, since the pattern information having a larger number of uses is defined with a smaller number of bits, the total number of used bits can be greatly reduced. Therefore, the data size can be greatly reduced. As a result, the drawing time can be shortened and the throughput of the apparatus can be improved. In addition, since drawing data for which the total number of used bits is greatly reduced is input, the transfer time can be greatly shortened.

  Hereinafter, in the embodiment, a configuration using an electron beam will be described as an example of a charged particle beam. However, the charged particle beam is not limited to an electron beam, and a beam using charged particles such as an ion beam may be used. As an example of the charged particle beam apparatus, a charged particle beam drawing apparatus, particularly, a variable shaping type electron beam drawing apparatus will be described.

Embodiment 1 FIG.
In the first embodiment, a case where there is no array-defined graphic data will be described. For example, a case where each figure is defined by each pattern information of a figure code, a figure size, and a figure coordinate will be described.

FIG. 1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to the first embodiment.
In FIG. 1, a drawing apparatus 100 is an example of an electron beam drawing apparatus. The drawing apparatus 100 draws a pattern composed of a plurality of figures on the sample 101. The sample 101 includes a mask for use in a lithography process when manufacturing a semiconductor device. The drawing apparatus 100 includes a drawing unit 150 and a control unit 160. The drawing unit 150 includes a drawing chamber 103 and an electronic lens barrel 102 disposed on the upper portion of the drawing chamber 103. In the electron column 102, an electron gun 201, an illumination lens 202, a first aperture 203, a projection lens 204, a deflector 205, a second aperture 206, an objective lens 207, and a deflector 208 are arranged. An XY stage 105 is arranged in the drawing chamber 103, and a sample 101 to be drawn is arranged on the XY stage 105. The control unit 160 includes magnetic disk devices 110, 116, 122, 126, a data processing unit 112, memories 114, 120, 128, a control computer 118, a shot data generation unit 124, and a drawing control unit 130. The magnetic disk devices 110, 116, 122, 126, the data processing unit 112, the memories 114, 120, 128, the control computer 118, the shot data generation unit 124, and the drawing control unit 130 are connected to each other by a bus (not shown). Has been. In the control computer 118, a block division unit 40, a cell arrangement unit 42, a cluster division unit 44, a pattern division unit 46, a pattern data recording unit 48, a cumulative table creation unit 50, a Huffman tree creation unit 52, and a Huffman table creation unit 54 , And a format conversion unit 56 are arranged. The magnetic disk devices 110, 116, 122, and 126 and the memories 114, 120, and 128 are examples of storage units or storage devices. In addition, drawing data is stored in the external magnetic disk device 500.

  Here, the block division unit 40, the cell arrangement unit 42, the cluster division unit 44, the pattern division unit 46, the pattern data recording unit 48, the cumulative table creation unit 50, the Huffman tree creation unit 52, the Huffman table creation unit 54, and the format conversion The unit 56 may be configured as each processing function executed by a computer such as a CPU that executes a program. Alternatively, the block division unit 40, the cell arrangement unit 42, the cluster division unit 44, the pattern division unit 46, the pattern data recording unit 48, the cumulative table creation unit 50, the Huffman tree creation unit 52, the Huffman table creation unit 54, and the format conversion unit Each of the 56 configurations may be configured by hardware using an electric circuit. Or you may make it implement by the combination of the hardware and software by an electrical circuit. Alternatively, a combination of such hardware and firmware may be used. Further, in the case of implementation by software or in combination with software, information input to a computer that executes processing or information during and after arithmetic processing is stored in the memory 120 each time. Similarly, the data processing unit 112 or the shot data generation unit 124 may be configured as a computer such as a CPU that executes a program. Alternatively, each internal processing configuration may be configured by hardware using an electric circuit. Or you may make it implement by the combination of the hardware and software by an electrical circuit. Alternatively, a combination of such hardware and firmware may be used. In addition, when it is implemented by software or in combination with software, information input to a computer for executing processing or information during and after arithmetic processing is stored in the memory 114 for each time for the data processing unit 112. The shot data generation unit 124 is stored in the memory 128 each time.

  Further, each of the data processing unit 112, the control computer 118, or the shot data generation unit 124 may be composed of one computer or a plurality of computers. By configuring each computer with a plurality of computers, parallel processing can be performed. If parallel processing is performed, the processing speed can be increased.

  In FIG. 1, constituent parts necessary for explaining the first embodiment are described. Needless to say, the drawing apparatus 100 may normally include other necessary configurations.

FIG. 2 is a diagram illustrating an example of a hierarchical structure of drawing data according to the first embodiment.
In the drawing data, the drawing area is a layer of the chip 10, a layer of the stripe 20 virtually divided into strips in the y direction, for example, a layer of the block 30 into which the stripe 20 is divided, and at least one figure. A layer of a plurality of internal structural units such as a layer of the cell 32 configured, a layer of a cluster 34 obtained by dividing the cell 32, and a layer of a graphic 36 (pattern) constituting the cell 32 are hierarchized. ing. In general, a plurality of chips are laid out for a drawing region of one sample 101. Therefore, chip merge processing is performed in the data processing unit 112 described later, and a post-merging hierarchy as shown in FIG. 2 is configured. In this example, the chip area of the stripe 20 is divided into strips in the y direction. However, this is an example, and the chip area may be divided in the x direction parallel to the drawing surface and perpendicular to the y direction. . Alternatively, other directions parallel to the drawing surface may be used.

FIG. 3 is a flowchart showing the drawing method according to the first embodiment.
As described above, when performing electron beam drawing, first, the layout of a semiconductor integrated circuit is designed. Then, layout data (design data) in which the pattern layout is defined is generated. Then, the layout data is converted, and drawing data adapted to the drawing apparatus 100 is generated. The drawing data is read from the magnetic disk device 500 and input to the drawing device 100. In the drawing apparatus 100, drawing data is stored in the magnetic disk device 110. Then, as will be described later, after a plurality of data processing, it is generated as shot data for drawing.

  In S (step) 102, as a data processing step, the data processing unit 112 reads and inputs drawing data of each of the plurality of chips from the magnetic disk device 110. Then, the data processing unit 112 rearranges in the drawing area of the drawing apparatus 100 and performs chip merge processing. In addition, the data processing unit 112 may perform other data processing such as mirroring and scaling processing. Then, the drawing data after these processes are executed is stored in the magnetic disk device 116.

  In S104, as the block dividing step, the block dividing unit 40 expands the drawing data processed in the upper step, and virtually divides the chip 10 or each stripe 20 into a plurality of blocks 30 as shown in FIG. To do.

  In S106, as a cell placement step, the cell placement unit 42 further expands the drawing data and places the cells 32 laid out in each block 30.

  In S108, as a cluster dividing step, the cluster dividing unit 44 further expands the drawing data and virtually divides each cell 32 into a plurality of clusters 34 as shown in FIG.

  In S110, as a pattern dividing step, the pattern dividing unit 46 further develops the drawing data and divides each cluster 34 into a plurality of figures 36 (patterns) as shown in FIG. To do. The pattern division unit 46 divides the pattern to obtain pattern data (pattern information) such as the number of figures 36 in each cluster 34, the figure type, the figure size (L, M), and the arrangement coordinates (X, Y). Can be acquired. Therefore, the pattern dividing unit 46 can acquire information on the defined pattern based on the drawing data. That is, the pattern division unit 46 is an example of an acquisition unit.

  In S112, as a pattern data recording process, the pattern data recording unit 48, for each cluster 34, includes the figure number, figure type, figure size (L, M), and arrangement coordinates (X, Y) of the figure 36 obtained. The pattern data is recorded (stored) in the memory 120.

  In S114, as a cumulative table creation step, the cumulative table creation unit 50 creates a cumulative table (for each cluster 34) that associates each piece of pattern information with the number of times each piece of pattern information is used based on a plurality of pieces of obtained pattern information. First table) is created. The cumulative table creation unit 50 is an example of a first table creation unit. The created cumulative table is stored in the memory 120.

FIG. 4 is a diagram illustrating an example of the accumulation table in the first embodiment.
In FIG. 4, the accumulation table 60 defines each value of the figure code, the figure size (M, L), and the figure coordinates (x, y) and the number of times the value is used in association with each other. Here, for all graphic patterns arranged in the cluster 34, the graphic code, the graphic size width value M, the graphic size height value L, the graphic coordinate (x, y) x value, or the graphic coordinates (x, This is defined by counting the number of times the y value of y) becomes 0x11. However, in practice, the width value M of the graphic size, the height value L of the graphic size, the x value of the graphic coordinates (x, y), or the y value of the graphic coordinates (x, y) can be 0x11. Therefore, the cumulative addition is performed by the number of graphic patterns having a graphic code of 0x11 among all graphic patterns arranged in the cluster 34. Here, as an example, a case where the accumulated use count is 110 times is shown. Similarly, the figure code, figure size width value M, figure size height value L, figure coordinate (x, y) x value, or figure coordinate (x, y) y value is 0.1. Define by counting the number of times. Here, a case where the accumulated number of uses is, for example, 50 times is shown. Similarly, the number of times of 0.2 is counted and defined. Here, a case where the accumulated number of uses is, for example, 10 is shown. Similarly, the number of times of 0.3 is counted and defined. Here, a case where the accumulated number of uses is, for example, 10 is shown. Similarly, the number of times of 0.4 is counted and defined. Here, a case where the accumulated number of uses is, for example, 20 is shown. Similarly, the number of times of 0.5 is counted and defined. Here, a case where the accumulated number of uses is, for example, 25 is shown. Further, as will be described later, the figure code in one cluster 34, the figure size width value M, the figure size height value L, the x value of figure coordinates (x, y), and the figure coordinates (x, y). The y-value data is defined by a series of continuous codes. Therefore, EOS (End Of Stream) indicating the end of a series of data is shown as a special mark.

FIG. 5 is a conceptual diagram showing an example for explaining how to count the number of times of use in the first embodiment.
FIG. 5 shows a case where a figure having a width of 0.5 and a height of 0.4 is arranged at a position of coordinates (0.5, 0.4) from the reference position of the cluster. Each unit is AU. In this case, the value 0.4 is defined twice in the accumulation table 60 as the number of times the value 0.4 is used twice. In the accumulation table 60, the number of times is similarly counted for all the figures arranged in the cluster 34, and the accumulated value is defined.

  In S116, as a Huffman tree creation step, the Huffman tree creation unit 52 reads the accumulation table 60 from the memory 120, and creates a Huffman tree based on the accumulation table 60. The created Huffman tree is stored in the memory 120.

FIG. 6 is a diagram illustrating an example of a Huffman tree corresponding to the accumulation table of FIG.
In FIG. 6, a Huffman tree 70 has a root node 72 in the highest level 1 hierarchy, leaf nodes 74 and 76 in the level 2 hierarchy, leaf nodes 78 and 80 in the level 3 hierarchy, and leaf nodes in the level 4 hierarchy. 82 and 84, leaf nodes 86 and 88 are arranged in the level 5 hierarchy, leaf nodes 90 and 92 are arranged in the level 6 hierarchy, and leaf nodes 95 and 96 are arranged in the level 7 hierarchy. A root node 72 arranged in the level 1 hierarchy forms the first part of the Huffman tree 70. Two root 1 branches are connected to the root node 72. A leaf node 76 indicating the EOS of the special mark is arranged at the tip of one level 1 branch. The binary number “1” is defined in this branch. The leaf node 74 of the level 2 hierarchy is arranged at the tip of the other level 1 branch. The binary number “0” is defined in this branch. Two level 2 branches are connected to the leaf node 74. A leaf node 78 in the level 3 hierarchy is arranged at the tip of one level 2 branch. The binary number “0” is defined in this branch. At the tip of the other level 2 branch, a leaf node 80 of the pattern information value that is used most frequently is arranged. The binary number “1” is defined in this branch. Two level 3 branches are connected to the leaf node 78. A leaf node 82 of the level 4 hierarchy is arranged at the tip of one level 3 branch. The binary number “0” is defined in this branch. At the tip of the other level 3 branch, a leaf node 84 having the second most frequently used pattern information value is arranged. The binary number “1” is defined in this branch. Two level 4 branches are connected to the leaf node 82. A leaf node 86 of the level 5 hierarchy is arranged at the tip of one level 4 branch. The binary number “0” is defined in this branch. At the tip of the other level 4 branch, a leaf node 88 of the pattern information value having the third largest number of uses is arranged. The binary number “1” is defined in this branch. Two level 5 branches are connected to the leaf node 86. A leaf node 90 in the level 6 hierarchy is placed at the tip of one level 5 branch. The binary number “0” is defined in this branch. At the tip of the other level 5 branch, a leaf node 92 of the pattern information value having the fourth largest number of uses is arranged. The binary number “1” is defined in this branch. Two level 6 branches are connected to the leaf node 90. At the tip of one level 6 branch, a leaf node 95 of the pattern information value having the fifth highest number of uses is arranged as a level 7 hierarchy. The binary number “0” is defined in this branch. At the tip of the other level 6 branch, a leaf node 96 of the pattern information value that is the fifth most frequently used is arranged as a level 7 hierarchy. The binary number “1” is defined in this branch. In addition, the leaf nodes 74, 78, 82, 86, and 90 define the total number of times of use of the pattern information values of the leaf nodes arranged in the lower hierarchy than the respective nodes. In this way, the Huffman tree 70 is a tree in which the lower two pattern information values that are used less frequently are the two leaf nodes at the lowest hierarchy level, and the pattern information value that is used more frequently are the leaf nodes at the higher hierarchy level. Configure.

  In S118, as a Huffman table creation step, the Huffman table creation unit 54 reads the Huffman tree 70 from the memory 120, and based on the Huffman tree 70, each pattern information and pattern information with a higher number of uses are set to smaller values. A Huffman table (second table) is created in association with binary variable length codes obtained by encrypting pattern information. The Huffman table creation unit 54 is an example of a second table creation unit. The created Huffman table is stored in the memory 120.

FIG. 7 is a diagram illustrating an example of a Huffman table corresponding to the Huffman tree of FIG.
In FIG. 7, the Huffman table 94 defines each pattern information value in association with a binary variable length code. The Huffman tree 70 described above determines a variable length code as follows. In order to reach the leaf node 80 of the pattern information value “0x11” having the largest number of uses, the root node 72 must pass through the binary “0” branch and the “1” branch one by one. Therefore, the code of the value “0x11” becomes “01” of 2 bits. In order to reach the leaf node 84 having the second most frequently used pattern information value “0.1”, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 72 are used. And the binary "1" level 3 branch. Therefore, the code of the value “0.1” becomes “001” of 3 bits. In order to reach the leaf node 88 with the third most frequently used pattern information value “0.5”, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 72. And the binary "0" level 3 branch and the binary "1" level 4 branch. Therefore, the code of the value “0.5” becomes “0001” of 4 bits. In order to reach the leaf node 92 having the fourth most frequently used pattern information value “0.4”, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 72 are used. And a binary "0" level 3 branch, a binary "0" level 4 branch, and a binary "1" level 5 branch. Therefore, the code of the value “0.4” becomes “00001” of 5 bits. In order to reach the leaf node 95 with the fifth most frequently used pattern information value “0.2”, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 72 are used. Branch, binary "0" level 3 branch, binary "0" level 4 branch, binary "0" level 5 branch and binary "0" level 6 branch Must pass through. Therefore, the code of the value “0.2” is 6 bits “000000”. Similarly, in order to reach the leaf node 96 having the fifth most frequently used pattern information value “0.3”, the level “1” branch of binary “0” and the binary “0” from the root node 72 are used. Level 2 branch of binary "0", Level 3 branch of binary "0", Level 4 branch of binary "0", Level 5 branch of binary "0" and Binary "1" You must go through level 6 branches. Therefore, the code of the value “0.3” is 6 bits “000001”. In this way, the pattern information having a larger number of uses is encrypted such that the binary variable length code has a smaller value. That is, the pattern information having a larger number of uses can be set to a value having a smaller number of bits. The EOS code as a special mark is exceptionally defined as 1 bit “1” regardless of the number of times of use. Then, a Huffman table 94 in which each obtained pattern information is associated with the variable length code is created.

  In S120, as the format conversion step, the format conversion unit 56 reads the Huffman table 94, and based on the Huffman table 94, the data in a predetermined area defined in the drawing data in a predetermined format using a variable length code. Convert. By converting the format of the drawing data, it is possible to generate intermediate data that is a stage before being converted into shot data.

FIG. 8 is a diagram illustrating an example of intermediate data in the first embodiment.
In FIG. 8, in the generated intermediate data 12, a stripe number, a block header for a block data located in the stripe, and a block number are defined following the stripe header. Then, following the block number, a cell header and cell number for cell data arranged in the block, and a cluster header and cluster number for cluster data arranged in the cell are defined. Then, the graphic code, graphic size (L, M), and graphic coordinates (x, y) are defined for the first graphic 62 arranged in the cluster 34 following the cluster number. Then, following the data of the first graphic, the graphic code, graphic size (L, M), and graphic coordinates (X, Y) are divided into data for the second graphic 62 arranged in the same cluster 34. It is defined continuously without interruption. After defining all figures in one cluster 34 in this way, the cluster header and cluster number of the next cluster 34 are subsequently defined. The same is defined below. Here, the figure code, figure size (L, M), and figure coordinates (X, Y) are read from the Huffman table 94, and the codes for all figures 62 arranged in the same cluster 34 are connected. Defined as a series of continuous codes.

  In the conventional format, for example, in order to define a graphic code, for example, 17 bits, and in order to define a graphic size (L, M), for example, 17 bits for L and 17 bits for M are required. In order to define (X, Y), for example, a total of 68 bits, 17 bits for X and 17 bits for Y, were required. On the other hand, in the intermediate data 12 of FIG. 8, the figure code, L and M of the figure size (L, M), and x and y of the coordinates (x, y) are the sum of the bit values of the variable length code, respectively. Become. Here, if the most frequently used pattern information is, for example, the value “0x11”, two bits of “01” are sufficient. As a result, a reduction effect of 15 bits occurs. Further, for example, if the value “0.1” is used as the second most frequently used pattern information, if there are 3 bits “001”, all of L, M, x, and y have the values “0. If it is “1”, it would have been 12 bits where 68 bits were conventionally required.

  For example, when 3000 graphics are arranged in one cluster 34, 15000 graphics codes and values of L, M, x, and y are used in total. If the Huffman tree is used, the number of bits of the maximum length code can be made smaller than the conventional 17 bits even if the number of times of use is one. In the first embodiment, since the pattern information having a larger number of uses is a code having a smaller number of bits, the effect of reducing the number of bits is very large.

  As described above, the intermediate data in each cluster whose number of bits is significantly reduced as a result of the conversion is stored (stored) in the magnetic disk device 122. A Huffman table 94 is also stored (stored) in the magnetic disk device 122.

  In S122, as the shot data generation process, the shot data generation unit 124 reads the intermediate data and the Huffman table 94 from the magnetic disk device 122, and generates shot data. At that time, the shot data generation unit 124 refers to the Huffman table 94 for a continuous code defining the graphic code, graphic size (L, M) and graphic coordinates (x, y) defined in the read intermediate data, The intermediate data is expanded while replacing the original numerical values, and each figure is divided into shot figures. The shot data generated as described above is stored in the magnetic disk device 126.

FIG. 9 is a diagram illustrating an example of a continuous code that defines a figure code, a figure size (L, M), and a figure coordinate (x, y) for a plurality of figures arranged in the same cluster according to the first embodiment. .
In FIG. 9, for example, in a frame of a figure code, figure size (L, M) and figure coordinates (x, y) for a plurality of figures arranged in the same cluster of the code “0100100100000000000001” and the intermediate data. If it is defined, the Huffman table 94 is read out, and the following determination is made based on the Huffman table 94. First, it can be seen from the first “01” that the graphic code is “0x11”. It can be seen from the next “001” that the L value of the figure size is “0.1”. It can be seen from the next “001” that the M value of the figure size is “0.1”. It can be seen from the next “000000” that the x value of the graphic coordinates is “0.2”. It can be seen from the next “000000” that the y value of the graphic coordinates is “0.2”. The next “01” indicates that the graphic code of the next graphic arranged in the same cluster is “0x11”. In the same manner, the figure code, figure size (L, M), and figure coordinates (x, y) for all figures arranged in the same cluster are known. The last “1” indicates that the graphic codes, graphic sizes (L, M), and graphic coordinates (x, y) codes for all the figures arranged in the same cluster are completed.

  And the drawing part 150 is arrange | positioned in the sample 101 in a cluster as follows using the electron beam 200 controlled by the shot data based on the data in the cluster converted by the above several formats. Draw multiple patterns. The drawing unit 150 is controlled by the drawing control unit 130.

  The electron beam 200 emitted from the electron gun 201 illuminates the entire first aperture 203 having a rectangular shape, for example, a rectangular hole, by the illumination lens 202. Here, the electron beam 200 is first formed into a rectangle, for example, a rectangle. Then, the electron beam 200 of the first aperture image that has passed through the first aperture 203 is projected onto the second aperture 206 by the projection lens 204. The position of the first aperture image on the second aperture 206 is controlled by the deflector 205, and the beam shape and size can be changed. Then, the electron beam 200 of the second aperture image that has passed through the second aperture 206 is focused by the objective lens 207, deflected by the deflector 208, and the sample 101 on the XY stage 105 that is movably disposed. The desired position is irradiated.

FIG. 10 is a conceptual diagram for explaining the effect of reducing the number of bits by continuous bits in the first embodiment.
FIG. 10A shows a case where the graphic code is defined by a conventional bit number value and is defined by variable length bits for the graphic size (L, M) and the graphic coordinates (x, y). In such a case, every time the figure size (L, M) and figure coordinates (x, y) of one figure are defined, a remainder of the number of bits that does not reach the variable-length bit frame occurs. On the other hand, in the first embodiment, the figure code, figure size (L, M), and figure coordinates (x, y) for all figures arranged in the same cluster are set without gaps between the preceding and following figures. By defining it as a series of variable length codes in succession, it is possible to eliminate the extra bits that occur between graphics as shown in FIG.

  As described above, according to the first embodiment, the number of bits of the intermediate data is obtained by encrypting the figure code, the figure size (L, M), and the figure coordinates (x, y) into the variable length code using the Huffman tree. Can be greatly reduced. As a result, the data size of the intermediate data can be reduced, and the drawing time can be greatly shortened. As a result, the throughput of the apparatus can be greatly improved.

Embodiment 2. FIG.
In the first embodiment, the case where there is no graphic data defined as an array has been described. In the second embodiment, a case will be described in which graphic data having an array definition exists. For example, a case will be described in which each figure is defined by each pattern information of figure code, array flag, figure size, figure coordinates, number of array figures, and array pitch. Here, the configuration of the drawing apparatus according to the second embodiment is the same as that shown in FIG. The drawing method in the second embodiment is the same as that in FIG. The contents of each process from the data processing process (S102) to the pattern data recording process (S112) are the same as those in the first embodiment.

  In S114, as a cumulative table creation step, the cumulative table creation unit 50 creates a cumulative table (for each cluster 34) that associates each piece of pattern information with the number of times each piece of pattern information is used based on a plurality of pieces of obtained pattern information. First table) is created. The created cumulative table is stored in the memory 120.

FIG. 11 is a diagram illustrating an example of the accumulation table in the second embodiment.
In FIG. 11, the accumulation table 62 shows values of figure code, array flag, figure size (M, L), figure coordinates (x, y), number of array figures (Nx, Ny), and array pitch (Px, Py). And the number of times the value is used. Here, for all graphic patterns arranged in the cluster 34, graphic code, array flag, graphic size width value M, graphic size height value L, graphic coordinate (x, y) x value, or graphic coordinates (X, y) y value, array figure number (Nx, Ny) Nx value, array figure number (Nx, Ny) Ny value, array pitch (Px, Py) Px value, or array pitch (Px) , Py) is defined by counting the number of times that the Py value of 0x11 is obtained. However, actually, the width value M of the graphic size, the height value L of the graphic size, the x value of the graphic coordinates (x, y), the y value of the graphic coordinates (x, y), the number of array graphics (Nx, Ny), Ny value of array figure number (Nx, Ny), Px value of array pitch (Px, Py), and Py value of array pitch (Px, Py) cannot be 0x11. Of all the graphic patterns arranged in the cluster 34, the cumulative addition is performed by the number of graphic patterns having a graphic code or array flag of 0x11. Here, as an example, a case where the accumulated number of uses is 100 is shown. Similarly, figure code, array flag, figure size width value M, figure size height value L, figure coordinate x value, figure coordinate y value, array figure number Nx value, array figure number Ny value, The number of times that the Px value of the array pitch or the Py value of the array pitch becomes 0.1 is defined by counting. Here, a case where the accumulated number of uses is, for example, 50 times is shown. Similarly, the number of times of 0.2 is counted and defined. Here, a case where the accumulated number of uses is, for example, 20 is shown. Similarly, the number of times of 0.3 is counted and defined. Here, a case where the accumulated number of uses is, for example, 10 is shown. Similarly, the number of times of 0.4 is counted and defined. Here, a case where the accumulated number of uses is, for example, 5 is shown. Similarly, the number of times of F indicating the array flag is counted and defined. Here, a case where the accumulated number of uses is, for example, 1 is shown. Similarly, the number of times of 2 is counted and defined. Here, a case where the accumulated number of uses is, for example, 2 is shown. As in the first embodiment, the figure code, array flag, figure size width value M, figure size height value L, figure coordinate x value, figure coordinate y value, number of array figures in one cluster 34 The data of the Nx value, the Ny value of the number of array figures, the Px value of the array pitch, and the Py value of the array pitch are defined by a series of continuous codes. Therefore, EOS indicating the end of a series of data is shown as a special mark.

FIG. 12 is a conceptual diagram illustrating an example for explaining how to count the number of times of use of an array graphic in the second embodiment.
In FIG. 12, for example, two figures having a width of 0.1 and a height of 0.1 at the coordinates (0.2, 0.2) from the reference position of the cluster 34 in the x direction with a pitch of 0.2. The case where two are arranged with a pitch of 0.2 in the y direction is shown. Each unit is AU. In this case, the value 0.1 is defined as 2 times, the value 0.2 is defined as 4 times, and the value 2 is defined as 2 times in the accumulation table 62. In the accumulation table 62, the number of times is similarly counted for all the figures arranged in the cluster 34, and the accumulated value is defined.

  In S116, as a Huffman tree creation step, the Huffman tree creation unit 52 reads the accumulation table 62 from the memory 120, and creates a Huffman tree based on the accumulation table 62. The created Huffman tree is stored in the memory 120.

FIG. 13 is a diagram illustrating an example of a Huffman tree corresponding to the accumulation table of FIG.
In FIG. 13, the Huffman tree 170 includes a root node 172 in the highest level 1 hierarchy, leaf nodes 174 and 176 in the level 2 hierarchy, leaf nodes 178 and 180 in the level 3 hierarchy, and leaf nodes in the level 4 hierarchy. 182 and 184, leaf nodes 186 and 188 are arranged in the level 5 hierarchy, leaf nodes 190 and 192 are arranged in the level 6 hierarchy, leaf nodes 194 and 196 are arranged in the level 7 hierarchy, and leaf nodes 198 and 199 are arranged in the level 8 hierarchy. The A root node 172 arranged in the level 1 hierarchy constitutes the beginning of the Huffman tree 170. Two root 1 branches are connected to the root node 172. A leaf node 176 indicating the EOS of the special mark is disposed at the tip of one level 1 branch. The binary number “1” is defined in this branch. The leaf node 174 of the level 2 hierarchy is arranged at the tip of the other level 1 branch. The binary number “0” is defined in this branch. Two level 2 branches are connected to the leaf node 174. A leaf node 178 of the level 3 hierarchy is arranged at the tip of one level 2 branch. The binary number “0” is defined in this branch. The leaf node 180 of the pattern information value with the highest number of uses is arranged at the tip of the other level 2 branch. The binary number “1” is defined in this branch. Two level 3 branches are connected to the leaf node 178. A leaf node 182 of the level 4 hierarchy is arranged at the tip of one level 3 branch. The binary number “0” is defined in this branch. At the tip of the other level 3 branch, a leaf node 184 of the pattern information value having the second highest number of uses is arranged. The binary number “1” is defined in this branch. Two level 4 branches are connected to the leaf node 182. A leaf node 186 of the level 5 hierarchy is arranged at the tip of one level 4 branch. The binary number “0” is defined in this branch. At the tip of the other level 4 branch, a leaf node 188 of the pattern information value having the third largest number of uses is arranged. The binary number “1” is defined in this branch. Two level 5 branches are connected to the leaf node 186. At the tip of one level 5 branch, a leaf node 190 in the level 6 hierarchy is arranged. The binary number “0” is defined in this branch. At the tip of the other level 5 branch, a leaf node 192 of the pattern information value that is used the fourth most frequently is arranged. The binary number “1” is defined in this branch. Two level 6 branches are connected to the leaf node 190. A leaf node 194 of the level 7 hierarchy is arranged at the tip of one level 6 branch. The binary number “0” is defined in this branch. At the tip of the other level 6 branch, a leaf node 196 of the pattern information value having the fifth largest number of uses is arranged. The binary number “1” is defined in this branch. Two level 7 branches are connected to the leaf node 194. At the tip of one level 7 branch, a leaf node 199 of the pattern information value having the sixth largest number of uses is arranged as a level 8 hierarchy. The binary number “1” is defined in this branch. At the tip of the other level 7 branch, a leaf node 198 of the pattern information value having the seventh highest number of uses is arranged as a level 8 hierarchy. The binary number “0” is defined in this branch. In addition, the leaf nodes 174, 178, 182, 186, 190, and 194 define the total number of times of use of the pattern information values of the leaf nodes arranged in the lower hierarchy than the respective nodes. Thus, the Huffman tree 170 is a tree in which the lower two pattern information values that are used less frequently are the two leaf nodes at the lowest hierarchy level, and the pattern information value that is used more frequently are the leaf nodes at the higher hierarchy level Configure.

  In S118, as the Huffman table creation process, the Huffman table creation unit 54 reads the Huffman tree 170 from the memory 120, and based on the Huffman tree 170, each pattern information and pattern information with a higher number of uses are set to smaller values. A Huffman table (second table) is created in association with binary variable length codes obtained by encrypting pattern information. The Huffman table creation unit 54 is an example of a second table creation unit. The created Huffman table is stored in the memory 120.

FIG. 14 is a diagram illustrating an example of a Huffman table corresponding to the Huffman tree in FIG.
In FIG. 14, the Huffman table 98 defines each pattern information value and a binary variable-length code in association with each other. The Huffman tree 170 described above determines a variable length code as follows. In order to reach the leaf node 180 of the pattern information value “0x11” having the highest number of uses, the root node 172 must pass through the binary “0” branch and the “1” branch one by one. Therefore, the code of the value “0x11” becomes “01” of 2 bits. In order to reach the leaf node 184 with the second most frequently used pattern information value “0.1”, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 172 And the binary "1" level 3 branch. Therefore, the code of the value “0.1” becomes “001” of 3 bits. In order to reach the leaf node 188 of the pattern information value “0.2” having the third largest number of uses, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 172 And the binary "0" level 3 branch and the binary "1" level 4 branch. Therefore, the code of the value “0.2” is 4-bit “0001”. In order to reach the leaf node 192 of the pattern information value “0.3” having the fourth highest usage count, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 172 And a binary "0" level 3 branch, a binary "0" level 4 branch, and a binary "1" level 5 branch. Therefore, the code of the value “0.3” becomes “00001” of 5 bits. In order to reach the leaf node 196 of the pattern information value “0.4” that is the fifth most frequently used, the level 1 branch of binary “0” and the level 2 of binary “0” from the root node 172 Branch, binary "0" level 3 branch, binary "0" level 4 branch, binary "0" level 5 branch and binary "1" level 6 branch Must pass through. Therefore, the code of the value “0.4” becomes “000001” of 6 bits. In order to reach the leaf node 198 of the pattern information value “2” having the sixth largest number of uses, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 172. Branch, binary "0" level 3 branch, binary "0" level 4 branch, binary "0" level 5 branch and binary "0" level 6 branch And a binary "0" level 7 branch. Therefore, the code of the value “2” is 7 bits “0000000”. Further, in order to reach the leaf node 199 of the pattern information value “F” that is used the seventh most frequently, a level 1 branch of binary “0” and a level 2 of binary “0” from the root node 172. Branch, binary "0" level 3 branch, binary "0" level 4 branch, binary "0" level 5 branch and binary "0" level 6 branch And a binary "0" level 7 branch. Therefore, the code of the value “F” is “0000001” of 7 bits. In this way, the pattern information having a larger number of uses is encrypted such that the binary variable length code has a smaller value. That is, the pattern information having a larger number of uses can be set to a value having a smaller number of bits. The EOS code as a special mark is exceptionally defined as 1 bit “1” regardless of the number of times of use. Then, a Huffman table 98 in which each obtained pattern information and variable length code are associated is created.

  In S120, as the format conversion process, the format conversion unit 56 reads the Huffman table 98, and based on the Huffman table 98, the data in a predetermined area defined in the drawing data in a predetermined format using a variable length code. Convert. By converting the format of the drawing data, it is possible to generate intermediate data that is a stage before being converted into shot data.

FIG. 15 is a diagram illustrating an example of intermediate data according to the second embodiment.
In FIG. 15, in the generated intermediate data 12, a stripe number, a block header for block data located in the stripe, and a block number are defined following the stripe header. Then, following the block number, a cell header and cell number for cell data arranged in the block, and a cluster header and cluster number for cluster data arranged in the cell are defined. Then, for the first graphic 62 arranged in the cluster 34 following the cluster number, the graphic code, the array flag, the graphic size (L, M), the graphic coordinates (x, y), and the number of array graphics (Nx) , Ny) and array pitch (Px, Py) are defined. Then, following the data of the first graphic, for the second graphic 62 arranged in the same cluster 34, the graphic code, array flag, graphic size (L, M), graphic coordinates (x, y), The number of array figures (Nx, Ny) and the array pitch (Px, Py) are defined continuously without being divided into data. After defining all figures in one cluster 34 in this way, the cluster header and cluster number of the next cluster 34 are subsequently defined. The same is defined below. As in the first embodiment, the figure code, array flag, figure size (L, M), figure coordinates (x, y), number of array figures (Nx, Ny), and array pitch (Px, Py) are: Each code is read from the Huffman table 98, and the codes for all the figures 62 arranged in the same cluster 34 are connected and defined as a series of continuous codes.

  In the conventional format, in addition to the graphic code, graphic size (L, M), and graphic coordinates (x, y) described in the first embodiment, the array flag, the array graphic number Nx, the array graphic number Ny, and the array pitch Px For example, 17 bits each were required to define the array pitch Py. By making these variable-length codes having a smaller number of bits for pattern information having a larger number of uses, the effect of reducing the number of bits becomes very large.

  As described above, the intermediate data in each cluster whose number of bits is significantly reduced as a result of the conversion is stored (stored) in the magnetic disk device 122. A Huffman table 98 is also stored (stored) in the magnetic disk device 122.

FIG. 16 shows a figure code, array flag, figure size (L, M), figure coordinates (x, y), and number of array figures (Nx, Ny) for a plurality of figures arranged in the same cluster in the second embodiment. ) And an array pitch (Px, Py).
In FIG. 16, for example, the code “010000000000001001000100010001000100000010001... 1” and the figure code, the array flag, the figure size (L, M), and the figure coordinates (x, y) for a plurality of figures arranged in the same cluster of intermediate data. And the number of array figures (Nx, Ny) and the array pitch (Px, Py) are defined in the frame, the Huffman table 98 is read and the following determination is made based on the Huffman table 98. First, it can be seen from the first “01” that the graphic code is “0x11”. The next “0000000” indicates that it is “F” indicating that there is an array flag. It can be seen from the next “001” that the L value of the figure size is “0.1”. It can be seen from the next “001” that the M value of the figure size is “0.1”. It can be seen from the next “0001” that the x value of the graphic coordinates is “0.2”. It can be seen from the next “0001” that the y value of the graphic coordinates is “0.2”. The next “0000001” shows that the Nx value of the number of array figures is “2”. It can be seen from the next “0000001” that the Ny value of the number of array figures is “2”. It can be seen from the next “0001” that the Px value of the array pitch is “0.2”. It can be seen from the next “0001” that the Py value of the array pitch is “0.2”. Subsequently, the figure code, the array flag, the figure size (L, M), the figure coordinates (x, y), the number of array figures (Nx, Ny), and the array for all figures arranged in the same cluster. The pitch (Px, Py) is known. Then, by the last “1”, the figure code, the array flag, the figure size (L, M), the figure coordinates (x, y), and the number of array figures (Nx, N) for all the figures arranged in the same cluster. Ny) and the array pitch (Px, Py) codes have been completed.

  In S122, as a shot data generation step, the shot data generation unit 124 reads the intermediate data and the Huffman table 98 from the magnetic disk device 122, and generates shot data. At that time, the shot data generation unit 124 includes a graphic code, an array flag, a graphic size (L, M), a graphic coordinate (x, y), a number of array graphics (Nx, Ny) defined in the read intermediate data. The continuous data defining the array pitch (Px, Py) is expanded with reference to the Huffman table 98 while replacing the original data with the original data, and each figure may be divided into shot figures. The shot data generated as described above is stored in the magnetic disk device 126.

  And the drawing part 150 is arrange | positioned in the sample 101 in a cluster as follows using the electron beam 200 controlled by the shot data based on the data in the cluster converted by the above several formats. Draw multiple patterns. The drawing unit 150 is controlled by the drawing control unit 130. The drawing operation is the same as in the first embodiment.

  Here, the effect of reducing the number of bits is verified using one of certain drawing data. An example of a 90 nm generation wiring pattern was verified. The cluster size at that time was 6.4 μm. As a result, with the conventional method, the intermediate data graphic code, array flag, graphic size (L, M), graphic coordinates (x, y), number of array graphic (Nx, Ny), and array pitch (Px, The total of Py) frames required 13464 bits. On the other hand, according to the present embodiment, the intermediate data graphic code, array flag, graphic size (L, M), graphic coordinates (x, y), number of array graphic (Nx, Ny), and array pitch (Px, The total of Py) frames could be reduced to 5518 bits. Thereby, it was able to reduce to 59%.

  As described above, according to the present embodiment, the figure code, the array flag, the figure size (L, M), the figure coordinates (x, y), the number of array figures (Nx, Ny), and the array pitch in the Huffman tree. By encrypting (Px, Py) into a variable length code, the number of bits of intermediate data can be greatly reduced. As a result, the data size of the intermediate data can be reduced, and the drawing time can be greatly shortened. As a result, the throughput of the apparatus can be greatly improved.

Embodiment 3 FIG.
In the first and second embodiments, the pattern information of each figure is encrypted into a variable length code for data processing after the drawing apparatus 100 inputs drawing data, but the present invention is not limited to this. In the third embodiment, a case will be described in which the drawing apparatus 100 inputs drawing data obtained by encrypting the pattern information of each figure into a variable length code before the drawing apparatus 100 inputs.

FIG. 17 is a conceptual diagram illustrating a configuration of a drawing apparatus according to the third embodiment.
17 is the same as FIG. 1 except that a control computer 113 is provided instead of the data processing unit 112 and a decoder 58 and a data processing unit 59 are arranged in the control computer 113. Here, the decoder 58 and the data processing unit 59 may be configured as each processing function executed by a computer such as a CPU that executes a program. Or you may comprise each structure of the decoder 58 and the data processing part 59 with the hardware by an electric circuit. Or you may make it implement by the combination of the hardware and software by an electrical circuit. Alternatively, a combination of such hardware and firmware may be used. Further, in the case of implementation by software or in combination with software, information input to a computer that executes processing or information during and after arithmetic processing is stored in the memory 114 each time.

  FIG. 18 is a flowchart illustrating a drawing method according to the third embodiment. 18 is the same as FIG. 3 except that a restoration step (S101) is added before the data processing step (S102).

  In the third embodiment, similarly to the data structure of the graphic explained in the first embodiment, each pattern information of the graphic code, graphic size (L, M), and graphic coordinates (x, y) is converted into a variable length code in the Huffman tree. Encrypted drawing data is read from the magnetic disk device 500 and input to the drawing device 100. In the drawing apparatus 100, drawing data is stored in the magnetic disk device 110. In other words, the drawing in which the data in the cluster is created with a binary variable-length code in which each pattern information is encrypted so that the pattern information of a plurality of defined patterns and the pattern information with a higher number of uses become smaller. Data is stored in the magnetic disk device 110. The area is not limited to the cluster, but may be other areas. Here, since it is still a stage before the chip merge processing is performed, it is preferable to create a binary variable length code obtained by encrypting the pattern information of each figure for each frame area of each chip.

  In S101, as a decoder process, the decoder 58 reads the drawing data from the magnetic disk device 110, and restores the data in the predetermined area created by the variable length code. The decoder 58 is an example of a restoration unit. The decoder 58 restores the variable length code to the original numerical value with reference to the Huffman table. The input Huffman table for drawing data may be input to the magnetic disk device 110 together with the drawing data. A plurality of patterns are drawn on the sample 101 by the drawing unit 150 after performing subsequent data processing based on the restored data. The contents of each step after the data processing step (S102) are the same as those in the first embodiment.

  Further, each of the graphic code, the array flag, the graphic size (L, M), the graphic coordinates (x, y), the number of array graphics (Nx, Ny), and the array pitch (Px, Py) described in the second embodiment. It is also preferable that the drawing apparatus 100 inputs drawing data obtained by encrypting pattern information into a variable length code. In such a case, restoration is performed in the restoration step (S101), and the contents of the subsequent steps are the same as those in the second embodiment.

  As described above, in addition to the case where it is used inside the drawing apparatus 100, the entire used bits of the input drawing data itself can be obtained by encrypting each pattern information into a variable length code before the apparatus inputs it. The number is greatly reduced. The transfer time to the drawing apparatus 100 can be greatly shortened by inputting drawing data in which the number of used bits is significantly reduced. Therefore, it is possible to shorten the time from the drawing data transfer process to the completion of drawing, and the throughput can be greatly reduced.

  The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the format is selected for each cluster, but the present invention is not limited to this. For example, the format may be selected for each cell.

  In addition, although descriptions are omitted for parts and the like that are not directly required for the description of the present invention, such as a device configuration and a control method, a required device configuration and a control method can be appropriately selected and used. For example, although the description of the control unit configuration for controlling the drawing apparatus 100 is omitted, it goes without saying that the required control unit configuration is appropriately selected and used.

  In addition, all drawing data creation devices, drawing data creation methods, drawing data conversion devices, drawing data conversion methods, charged particle beam drawing devices, which include elements of the present invention and can be appropriately modified by those skilled in the art, and The drawing method is included in the scope of the present invention.

1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to Embodiment 1. FIG. 6 is a diagram illustrating an example of a hierarchical structure of drawing data according to Embodiment 1. FIG. 3 is a flowchart showing a drawing method in Embodiment 1. FIG. 6 is a diagram illustrating an example of an accumulation table in Embodiment 1. FIG. FIG. 3 is a conceptual diagram illustrating an example for explaining how to count the number of uses in the first embodiment. It is a figure which shows an example of the Huffman tree corresponding to the accumulation table of FIG. It is a figure which shows an example of the Huffman table corresponding to the Huffman tree of FIG. 6 is a diagram illustrating an example of intermediate data in the first embodiment. FIG. 6 is a diagram illustrating an example of a continuous code that defines a figure code, a figure size (L, M), and a figure coordinate (x, y) for a plurality of figures arranged in the same cluster according to Embodiment 1. FIG. FIG. 6 is a conceptual diagram for explaining the effect of reducing the number of bits by continuous bits in the first embodiment. FIG. 10 is a diagram illustrating an example of an accumulation table in the second embodiment. FIG. 10 is a conceptual diagram showing an example for explaining how to count the number of times an array graphic is used in the second embodiment. It is a figure which shows an example of the Huffman tree corresponding to the accumulation table of FIG. It is a figure which shows an example of the Huffman table corresponding to the Huffman tree of FIG. 6 is a diagram illustrating an example of intermediate data in Embodiment 2. FIG. Graphic code, array flag, graphic size (L, M), graphic coordinates (x, y), number of array graphic (Nx, Ny), and array pitch for a plurality of graphics arranged in the same cluster in the second embodiment It is a figure which shows an example of the continuous code which defines (Px, Py). FIG. 10 is a conceptual diagram illustrating a configuration of a drawing apparatus according to a third embodiment. FIG. 10 is a flowchart showing a drawing method in the third embodiment. It is a conceptual diagram for demonstrating operation | movement of the conventional variable shaping type | mold electron beam drawing apparatus.

Explanation of symbols

10 chip 12 intermediate data 20 stripe 30 block 32 cell 34 cluster 36 figure 40 block division unit 42 cell arrangement unit 44 cluster division unit 46 pattern division unit 48 pattern data recording unit 50 cumulative table creation unit 52 Huffman tree creation unit 54 Huffman table creation Unit 56 Format conversion unit 58 Decoder 59, 112 Data processing unit 60, 62 Accumulation table 70, 170 Huffman tree 72, 172 Root nodes 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 95, 96 Leaf nodes 174, 176, 178, 180, 182, 184, 186, 188 Leaf nodes 190, 192, 194, 196, 198, 199 Leaf nodes 94, 98 Huffman table 100 Drawing apparatus 101, 340 Sample 102 Electron tube 1 03 Drawing room 105 XY stage 110, 116, 122, 126, 500 Magnetic disk device 113, 118 Control computer 114, 120, 128 Memory 124 Shot data generation unit 130 Drawing control unit 150 Drawing unit 160 Control unit 200 Electron beam 201 Electron gun 202 Illumination lenses 203, 410 First aperture 206, 420 Second aperture 204 Projection lens 205, 208 Deflector 207 Objective lens 330 Electron beam 411 Opening 421 Variable shaping opening 430 Charged particle source

Claims (5)

A storage unit for storing drawing data;
Based on the drawing data, an acquisition unit that acquires pattern information including at least one of a graphic code of a plurality of defined patterns, an array flag, the number of arrays, and an array pitch;
A first table creation unit that creates a first table that associates each piece of pattern information with the number of uses of each piece of pattern information based on a plurality of pieces of acquired pattern information for each predetermined region;
A Huffman tree creation unit for creating a Huffman tree based on the first table;
Based on the Huffman tree, a second table is created in which each pattern information is associated with a binary variable-length code obtained by encrypting each pattern information so that the pattern information having a larger number of uses has a smaller value. 2 table creation units;
A conversion unit for converting data in the predetermined area defined in the drawing data in a predetermined format using the variable length code based on the second table;
A drawing unit for drawing the plurality of patterns on a sample based on the converted data in the predetermined region;
A drawing apparatus comprising:   2. The drawing apparatus according to claim 1, wherein the converted data in the predetermined area includes data in which variable length codes of each pattern information are continuous. A drawing created with a binary variable-length code in which each pattern information is encrypted so that the data in a predetermined area has a smaller value as the pattern information of a plurality of defined patterns and the pattern information with a higher number of uses. A storage unit for storing data;
A restoration unit for restoring data in the predetermined area;
A drawing unit for drawing the plurality of patterns on the sample based on the restored data;
A drawing apparatus comprising: Inputting drawing data; and
Acquiring pattern information including at least one of a graphic code, an array flag, an array number, and an array pitch of a plurality of defined patterns based on the drawing data;
Creating a first table that associates each piece of pattern information with the number of uses of each piece of pattern information based on a plurality of pieces of acquired pattern information for each predetermined region;
Creating a Huffman tree based on the first table;
A step of creating a second table based on the Huffman tree and associating each pattern information with a binary variable length code obtained by encrypting each pattern information so that the pattern information having a larger number of uses has a smaller value. When,
Converting the data in the predetermined area defined in the drawing data in a predetermined format using the variable length code based on the second table;
Storing the converted data in the predetermined area;
A drawing data conversion method characterized by comprising: A drawing created with a binary variable-length code in which each pattern information is encrypted so that the data in a predetermined area has a smaller value as the pattern information of a plurality of defined patterns and the pattern information with a higher number of uses. Inputting data,
Restoring the data in the predetermined area;
Drawing the plurality of patterns on the sample based on the restored data;
A drawing method characterized by comprising:

Images