Electron beam lithography apparatus, electron beam lithography method, and program

Abstract

Conventionally, it has not been possible to quickly obtain an appropriate dose when drawing a pattern using an electron beam. [Solution] An electron beam drawing device comprising: a density set storage unit in which a set of first density information corresponding to the area of ​​the figure contained in each of two or more first small areas obtained by dividing a figure area specified by the figure information is stored for each of one or more pieces of figure information; a density set acquisition unit 33 that acquires the first density sets corresponding to each of the one or more pieces of figure information from the density set storage unit; a correction amount acquisition unit that acquires the correction amount for each of two or more second small areas, which is a correction amount corresponding to one or more first density sets for each of the one or more pieces of figure information; an irradiation amount acquisition unit that acquires an electron beam irradiation amount of an intensity corresponding to the correction amount for each of the two or more second small areas for each of the two or more second small areas; and a drawing unit that irradiates each of the two or more second small areas with an electron beam in accordance with the irradiation amount for each of the two or more second small areas, thereby making it possible to quickly acquire an appropriate irradiation amount when drawing a figure using an electron beam.

Description

[Technical Field]

[0001] The present invention relates to an electron beam lithography apparatus and the like that performs electron beam irradiation. [Background technology]

[0002] Conventionally, there have been techniques for correcting the irradiation amount of charged particle beams emitted from a drawing device (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 6283180 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, conventional techniques could not quickly determine the appropriate irradiation dose when drawing shapes using an electron beam. In conventional techniques, especially when the affected area of ​​the phenomenon to be corrected, such as the area affected by the electron beam irradiation, was wide, and when the number of shapes was enormous, it took a considerable amount of time to process and determine the appropriate irradiation dose. [Means for solving the problem]

[0005] The electron beam lithography apparatus of the first invention comprises: a density set storage unit in which a first density set is a set of first density information corresponding to the area in which the figure indicated by the graphic information is contained within each of two or more first sub-regions obtained by dividing the graphic region specified by the graphic information, and this first density set is a set of first density information for each of two or more first sub-regions, and this first density set is stored for each of one or more graphic information; a graphic information receiving unit that receives one or more graphic information; a density set acquisition unit that acquires a first density set corresponding to each of the one or more graphic information received by the graphic information receiving unit from the density set storage unit; a correction amount acquisition unit that acquires a correction amount corresponding to each of two or more second sub-regions, which is a correction amount for each of one or more graphic information; an irradiation amount acquisition unit that acquires an electron beam irradiation amount of strength corresponding to each of two or more second sub-regions, which is a set of first density information for each of two or more first sub-regions, which is a set of first density information for each of two or more first sub-regions, and this first density set is stored for each of one or more graphic information; a graphic information receiving unit that receives one or more graphic information; a density set acquisition unit that acquires a first density set corresponding to each of the one or more graphic information received by the graphic information receiving unit; a correction amount acquisition unit that acquires a correction amount corresponding to each of two or more first density sets for each of one or more graphic information; an irradiation amount acquisition unit that acquires an electron beam for each of two or more second sub-regions, according to the irradiation amount for each of two or more second sub-regions acquired by the irradiation amount acquisition unit.

[0006] This configuration allows for the rapid acquisition of the appropriate irradiation dose when drawing shapes using an electron beam.

[0007] Furthermore, the electron beam lithography apparatus of this second invention, compared to the first invention, comprises a density set acquisition unit which includes a density set reading means that acquires a first density set corresponding to one or more graphic information received by a reception unit from a density set storage unit, an area variation information acquisition means that acquires area variation information based on the graphic within the first sub-region for the first sub-region that matches the bias conditions relating to the graphic of the first sub-region among two or more first sub-regions, and a density set acquisition means that acquires a second density set, which is a set of second density information for one or more first sub-regions, for one or more graphic information, using the first density information of one or more first sub-regions contained in the first density set acquired by the density set reading means and the area variation information of one or more first sub-regions acquired by the area variation information acquisition means, and a correction amount acquisition unit which acquires correction amounts for two or more second sub-regions using one or more second density sets acquired by the density set acquisition means.

[0008] This configuration allows for the rapid acquisition of a more appropriate irradiation dose when drawing shapes using an electron beam.

[0009] Furthermore, the electron beam lithography apparatus of this third invention further comprises, compared to the second invention, a differential information storage unit that stores differential information specifying the variation in area with respect to a unit amount of bias for each of the one or more graphic information items and for each of the two or more first sub-regions, and a bias amount receiving unit that receives the bias amount, and the area variation information acquisition means acquires area variation information for each of the one or more graphic information items for each first sub-region that matches the bias condition, using the differential information associated with the first sub-region and the bias amount received by the bias amount receiving unit.

[0010] This configuration allows for the rapid acquisition of a more appropriate irradiation dose when drawing shapes using an electron beam.

[0011] Furthermore, the electron beam lithography apparatus of the fourth invention is an electron beam lithography apparatus that, compared to the third invention, further comprises a second preprocessing unit that calculates differential information that specifies the variation in area with respect to a unit amount of bias for each of the one or more graphic information items and each of the two or more first sub-regions, and stores it in a differential information storage unit.

[0012] This configuration allows for the rapid acquisition of a more appropriate irradiation dose when drawing shapes using an electron beam.

[0013] Furthermore, the electron beam lithography apparatus of this fifth invention, compared to the fourth invention, has a differential information calculation formula for calculating differential information stored for each of the one or more bias conditions, and the second preprocessing unit acquires a differential information calculation formula corresponding to the matching bias condition for each of the one or more graphic information and each of the two or more first sub-regions, calculates differential information using the differential information calculation formula, and stores it in the differential information storage unit.

[0014] This configuration allows for the rapid acquisition of a more appropriate irradiation dose when drawing shapes using an electron beam.

[0015] Further, in the electron beam lithography apparatus of the sixth invention, with respect to any one of the third to fifth inventions, the bias condition is that the pattern in the first small region includes a horizontal line or a vertical line, and the area variation information acquisition means acquires area variation information having a magnitude proportional to the bias amount with respect to the horizontal line or the vertical line.

[0016] With such a configuration, an appropriate irradiation amount when drawing a pattern using an electron beam can be acquired at high speed.

[0017] Also, in the electron beam lithography apparatus of the seventh invention, with respect to any one of the third to fifth inventions, the bias condition is that the pattern in the first small region includes a slanted line, and the area variation information acquisition means acquires angle information regarding the bias amount and the angle of the slanted line and length information regarding the length within the first small region of the slanted line, and calculates X area variation information, which is area variation information of the X component, and Y area variation information, which is area variation information of the Y component, using the bias amount, the angle information, and the length information, and calculates area variation information using the X area variation information and the Y area variation information.

[0018] With such a configuration, an appropriate irradiation amount when drawing a pattern using an electron beam can be acquired at high speed.

[0019] Further, in the electron beam lithography apparatus of the eighth invention, with respect to any one of the third to fifth inventions, the bias condition is that the pattern in the first small region includes a corner portion formed by the intersection of two straight lines, and the area variation information acquisition means calculates the areas of a parallelogram created by extending the two straight lines by lengths corresponding to the bias amount and two triangles, and calculates area variation information using the three areas.

[0020] With such a configuration, an appropriate irradiation amount when drawing a pattern using an electron beam can be acquired at high speed.

[0021] Furthermore, the electron beam lithography apparatus of the ninth invention is an electron beam lithography apparatus that, in addition to any one of the first to eighth inventions, further comprises a first preprocessing unit which acquires first density information based on the area in which the figure indicated by the figure information is contained within each of the two or more first sub-regions obtained by dividing the figure region which is the region specified by the figure information, acquires a first density set which is a collection of first density information for each of the one or more figure information, and stores it in a density set storage unit.

[0022] This configuration allows for the rapid acquisition of a more appropriate irradiation dose when drawing shapes using an electron beam.

[0023] Furthermore, the density set production apparatus of the tenth invention comprises a graphic information receiving unit that receives one or more graphic information, and a first preprocessing unit that, for each of the two or more first sub-regions obtained by dividing the graphic region which is the region specified by the graphic information, acquires first density information based on the area in which the graphic information is contained within each of the two or more first sub-regions, and acquires and stores a first density set which is a collection of first density information for each of the one or more graphic information.

[0024] This configuration allows for the acquisition and storage of density sets.

[0025] Furthermore, the differential information set production apparatus of the eleventh invention comprises a graphic information receiving unit that receives one or more graphic information, and a second preprocessing unit that calculates and stores differential information that identifies the variation in area with respect to a unit quantity of bias for each of the one or more graphic information and for each of the two or more first sub-regions.

[0026] This configuration allows for the acquisition and storage of differential information sets. [Effects of the Invention]

[0027] According to the electron beam lithography apparatus of the present invention, the appropriate irradiation dose when drawing a figure using an electron beam can be obtained at high speed. [Brief explanation of the drawing]

[0028] [Figure 1] Block diagram of electron beam lithography apparatus A in Embodiment 1 [Figure 2] A diagram illustrating the derivation of an example of the differential information calculation formula. [Figure 3] A diagram illustrating the derivation of an example of the differential information calculation formula. [Figure 4] A diagram illustrating the derivation of an example of the differential information calculation formula. [Figure 5] A diagram illustrating the derivation of an example of the differential information calculation formula. [Figure 6] A diagram illustrating the derivation of an example of the differential information calculation formula. [Figure 7] A flowchart illustrating an example of the operation of the electron beam lithography system A. [Figure 8] A flowchart illustrating an example of the process for acquiring density information. [Figure 9] A flowchart illustrating an example of the process for obtaining differential information. [Figure 10] A flowchart illustrating an example of the process for obtaining sets of identical density. [Figure 11] A flowchart illustrating an example of obtaining a set of correction quantities. [Figure 12] A flowchart illustrating an example of the same drawing process. [Figure 13] This diagram illustrates the processing of the first preprocessing unit 31. [Figure 14] This figure shows an example of the first density map. [Figure 15] This diagram illustrates the processing of the second preprocessing unit 32. [Figure 16] A diagram showing an example of the same differential information set. [Figure 17] Block diagram of production apparatus B with uniform density. [Figure 18] Block diagram of the production device C for the same differential information set. [Figure 19] Overview of the computer system [Figure 20] Block diagram of the computer system [Modes for carrying out the invention]

[0029] The following describes embodiments of the electron beam lithography apparatus and the like with reference to the drawings. Note that components denoted by the same reference numerals in the embodiments perform similar operations, and therefore, further explanation may be omitted.

[0030] (Embodiment 1) In this embodiment, for each of the two or more first sub-regions obtained by dividing a region containing one or more graphic information items, first density information corresponding to the area containing the graphic is acquired, and a set of first density information associated with a first sub-region identifier is maintained in advance. Then, using the set of first density information for each of the one or more graphic information items, a set of correction amounts for each second sub-region is acquired, and for each second sub-region, the electron beam irradiation amount is determined according to the corresponding correction amount, and an electron beam lithography apparatus that irradiates with an electron beam according to the irradiation amount will be described.

[0031] Furthermore, this embodiment describes an electron beam lithography apparatus that creates a more appropriate set of correction amounts by performing bias processing, determines the electron beam irradiation amount according to the set of correction amounts, and irradiates with the electron beam according to the irradiation amount.

[0032] Furthermore, in this embodiment, differential information, which is information on the change in area with respect to a unit amount of bias, is stored in advance for each first sub-region, and a more appropriate set of correction amounts is created using this differential information, the irradiation amount of the electron beam is determined according to the set of correction amounts, and the electron beam is irradiated according to the irradiation amount is described.

[0033] Figure 1 is a block diagram of electron beam lithography apparatus A in this embodiment. Electron beam lithography apparatus A comprises a storage unit 1, a receiving unit 2, a processing unit 3, and an output unit 4.

[0034] The storage unit 1 comprises a density set storage unit 11 and a differential information storage unit 12. The receiving unit 2 comprises a graphic information receiving unit 21 and a bias amount receiving unit 22. The processing unit 3 comprises a first pre-processing unit 31, a second pre-processing unit 32, a density set acquisition unit 33, a correction amount acquisition unit 34, an irradiation amount acquisition unit 35, and a drawing unit 36. The density set acquisition unit 33 comprises a density set reading means 331, an area variation information acquisition means 332, and a density set acquisition means 333.

[0035] Storage unit 1 stores various types of information. These types of information include, for example, density sets (described later), differential information (described later), one or more geometric information, one or more bias conditions, one or more differential information calculation formulas, and various calculation formulas (described later).

[0036] Graphic information refers to information that describes a shape. For example, graphic information can be a set of coordinate information for two or more points that make up a shape. It can also be a set of information for three or more lines that make up a shape. Furthermore, graphic information can be a file. However, the structure of the graphic information is not specified. Also, graphic information is associated with a graphic identifier. A graphic identifier is information that identifies a shape, such as an ID, file name, or shape name.

[0037] Bias conditions are the conditions for obtaining area variation information, which will be described later. Bias conditions are usually conditions related to the shape of the first sub-region. For example, a bias condition is that there are areas within the first sub-region where drawings exist and areas where no shapes exist. Another bias condition is that there are lines of drawings within the first sub-region. Note that lines of drawings refer to the boundaries of drawings. Another bias condition is that there are horizontal lines of drawings within the first sub-region. Another bias condition is that there are vertical lines of drawings within the first sub-region. Another bias condition is that there are diagonal lines of drawings within the first sub-region. Another bias condition is that there are corners of drawings within the first sub-region. A corner is the part of a shape formed by the intersection of two straight lines.

[0038] Furthermore, the first sub-region may contain a part of a figure, or it may contain one or more figures.

[0039] A differential information calculation formula is an operation formula used to calculate differential information. Differential information calculation formulas are usually associated with bias conditions. Specific examples of differential information calculation formulas will be discussed later.

[0040] The density set storage unit 11 stores a first density set for each of the one or more graphic information items. Each of the one or more first density sets is associated, for example, with a graphic identifier that identifies the graphic information.

[0041] The first density set contains two or more first density information entries. The first density set is a collection of first density information entries for each of the two or more first sub-regions. For example, the first density set consists of two or more first density pair information entries. A first density pair information entry is a pair of a first sub-region identifier that identifies a first sub-region and first density information. The first density set may also be called a first density map.

[0042] The first density information is, for example, associated with the first sub-region identifier. The first density information is, for example, associated with region information that identifies the first sub-region (for example, information having top-left and bottom-right coordinates). The first density information is information corresponding to the area that the shape indicated by the graphic information is contained within the first sub-region. The first density information is, for example, information about the density of drawings within the first sub-region. The first density information is, for example, information about the proportion of the total area within the first sub-region that the shape occupies. The first density information is, for example, a numerical value between 0 and 1. The first density information is, for example, information about the area that the shape occupies within the first sub-region. The first density information may also be the area that the shape occupies within the first sub-region.

[0043] It is preferable that one or more first density sets in the density set storage unit 11 are information acquired by the first preprocessing unit 31. It is preferable that one or more first density sets in the density set storage unit 11 are information accumulated in the density set storage unit 11 by processing performed by the first preprocessing unit 31 as preprocessing before receiving the instruction to start drawing.

[0044] The size and shape of each of the two or more first sub-regions may differ. Furthermore, the size and shape of the first sub-regions may differ depending on the geometric information, as the division method may vary according to the geometric information. However, a rectangular shape is preferable.

[0045] The differential information storage unit 12 stores differential information associated with the first sub-region. For example, the differential information storage unit 12 stores differential information associated with one or more first sub-regions.

[0046] The differential information storage unit 12 stores a set of differential information for each of the one or more geometric information items. Each set of differential information in the differential information storage unit 12 is associated with, for example, a geometric identifier.

[0047] A differential information set is a set of one or more differential information items. Each differential information item in the differential information set corresponds to a first sub-region. Each differential information item in the differential information set is associated with, for example, a first sub-region identifier. Each differential information item in the differential information set is associated with, for example, the region information of the first sub-region.

[0048] Differential information identifies the variation in area relative to a unit quantity of bias. The unit quantity is, for example, 1 nm, but is not limited to that. Bias refers to the movement of part or all of the contours that make up the original shape in order to correct when the pattern is not formed as designed during the drawing process or after the drawing process, such as development and etching.

[0049] It is preferable that one or more differential information entries in the differential information storage unit 12 are information acquired by the second preprocessing unit 32. It is also preferable that one or more differential information entries in the differential information storage unit 12 are information stored in the differential information storage unit 12 by processing performed by the second preprocessing unit 32 as preprocessing before receiving the instruction to start drawing.

[0050] Reception unit 2 receives various types of information and instructions. These types of information and instructions include, for example, graphic information (described later), bias amount (described later), pre-processing instructions, and start instructions.

[0051] A preprocessing instruction is an instruction to perform preprocessing on one or more pieces of graphic information. Preprocessing is a process performed before receiving a drawing start instruction. For example, preprocessing is the acquisition of density sets performed by the first preprocessing unit 31. For example, preprocessing is the acquisition of differential information performed by the second preprocessing unit 32.

[0052] A start instruction is an instruction to begin drawing a shape. Preferably, a start instruction includes one or more pieces of shape information.

[0053] Here, "reception" refers, for example, to obtaining information acquired by a processing means (not shown) from that processing means. Furthermore, "reception" may also be a concept that includes receiving information transmitted via wired or wireless communication lines, receiving information read from recording media such as optical discs, magnetic discs, and semiconductor memory, and receiving information input from input devices such as keyboards, mice, and touch panels. In other words, it does not matter how the information or instructions to be received are received.

[0054] The graphic information receiving unit 21 receives one or more graphic information. The graphic information receiving unit 21 may acquire one or more graphic information contained in the start instruction received by the receiving unit 2. The graphic information receiving unit 21 may acquire one or more graphic information from the storage unit 1.

[0055] The bias amount receiving unit 22 receives the bias amount. The bias amount receiving unit 22 may, for example, receive the bias amount from the user. However, the method of receiving the bias amount is not limited.

[0056] Furthermore, the bias amount receiving unit 22 may accept different bias amounts for each piece of graphic information. Also, the bias amount receiving unit 22 may accept different bias amounts for each of the one or more shapes contained in the graphic information. Furthermore, the bias amount receiving unit 22 may accept different bias amounts for each component (e.g., line segment) that constitutes the shape. In addition, the bias amount receiving unit 22 may accept different bias amounts for each part of each component (e.g., line segment) that constitutes the shape.

[0057] The processing unit 3 performs various processes. These various processes include, for example, the processes performed by the first preprocessing unit 31, the second preprocessing unit 32, the density aggregation acquisition unit 33, the correction amount acquisition unit 34, and the irradiation amount acquisition unit 35. The processing unit 3 modifies the graphic information according to the bias amount received by the bias amount receiving unit 22. This process is called bias processing.

[0058] The first preprocessing unit 31 acquires density information for each of the two or more first sub-regions obtained by dividing the region containing the geometric region, which is the region specified by the geometric information. The first preprocessing unit 31 then acquires a density set, which is the collection of density information for each of the two or more first sub-regions, and stores the density set in the density set storage unit 11. The size of the first sub-region is not specified.

[0059] It is preferable for the first preprocessing unit 31 to acquire a density set for each of the one or more graphic information that the graphic information receiving unit 21 can receive, and to store the density set in the density set storage unit 11 in association with the graphic information. In other words, it is preferable for the first preprocessing unit 31 to operate before the drawing unit 36 ​​performs processing, and to store the density set in the density set storage unit 11 in association with each of the one or more graphic information. Such preprocessing shortens the processing time from when the graphic information receiving unit 21 receives the graphic information until the drawing unit 36 ​​performs processing.

[0060] The first preprocessor 31, for example, obtains the area of ​​the graphic information contained within each first sub-region of the graphic information from the graphic information. Then, the first preprocessor 31 obtains the density information of the first sub-region using an increasing function with the area as a parameter. Alternatively, the first preprocessor 31 may obtain the area of ​​the entire first sub-region and obtain density information which is the ratio of the area of ​​the graphic information to the total area. The first preprocessor 31 obtains density information using the formula "density information = area of ​​the graphic within the first sub-region / total area of ​​the first sub-region". The first preprocessor 31 may also obtain the area of ​​the graphic within the first sub-region itself as density information.

[0061] If there are two or more figures within the first sub-region, the first pre-processing unit 31 obtains the area of ​​each of the multiple figures within the first sub-region and obtains the sum of these two or more areas. Then, the first pre-processing unit 31 obtains the density information of the first sub-region using an increasing function with the sum of the two or more areas as a parameter. For example, the first pre-processing unit 31 obtains the density information using the calculation formula "density information = sum of two or more areas / total area of ​​the first sub-region". The first pre-processing unit 31 may also obtain the sum of the two or more areas as the density information.

[0062] The second preprocessing unit 32 calculates differential information associated with each of the two or more first sub-regions for each of the one or more graphic information items and stores it in the differential information storage unit 12. Differential information is information that identifies the variation in area relative to a unit quantity of bias in the first sub-region.

[0063] The second preprocessing unit 32 stores the calculated differential information, for example, by associating it with the graphic identifier and the first sub-region identifier.

[0064] The second preprocessing unit 32 obtains, for example, a differential information calculation formula corresponding to the matching bias condition for each of the one or more graphic information items and each of the two or more first sub-regions from the storage unit 1, calculates the differential information using the differential information calculation formula, and stores it in the differential information storage unit 12.

[0065] The following explains the four cases in which the second preprocessor unit 32 calculates differential information, using examples of differential information calculation formulas for each case. The four cases are: (1) When the first sub-region contains a horizontal line. (2) When a vertical line is included in the first sub-region; (3) When a diagonal line is included in the first sub-region; (4) When a corner is included in the first sub-region. (1) When the first sub-region includes a horizontal line

[0066] The second preprocessor unit 32 calculates the length (L1) of the horizontal line of the figure within each of the first sub-regions for each of the one or more figure information and each of the two or more first sub-regions, using the region information and figure information of the first sub-region. Next, the second preprocessor unit 32 reads the constant (α1) from the storage unit 1 for each of the one or more figure information and each of the two or more first sub-regions, substitutes α1 and L1 into the following equation 1, executes equation 1, and obtains differential information. Next, the second preprocessor unit 32 stores the differential information in the differential information storage unit 12, associating it with the figure identifier and the first sub-region identifier for each of the one or more figure information and each of the two or more first sub-regions.

[0067]

number

[0068] In equation 1, α1 is a constant, and L1 is the length of the horizontal line of the first sub-region.

[0069] Furthermore, the differential information calculation formula in case (1) is not limited to formula 1. The differential information calculation formula in case (1) can be any increasing function with the length of the horizontal line (L1) as a parameter.

[0070] Furthermore, if there are multiple horizontal lines in the first sub-region, the second pre-processing unit 32 calculates differential information for each horizontal line and calculates the sum of the differential information for each horizontal line. This sum is the differential information for the first sub-region. (2) When a vertical line is included in the first sub-region

[0071] The second preprocessor unit 32 calculates the length (L2) of the vertical line of the figure within each of the first sub-regions for each of the one or more figure information and each of the two or more first sub-regions, using the region information and figure information of the first sub-region. Next, the second preprocessor unit 32 reads the constant (α2) from the storage unit 1 for each of the one or more figure information and each of the two or more first sub-regions, substitutes α2 and L2 into the following equation 2, executes equation 1, and obtains differential information. Next, the second preprocessor unit 32 stores the differential information in the differential information storage unit 12 for each of the one or more figure information and each of the two or more first sub-regions, associating it with the figure identifier and the first sub-region identifier.

[0072]

number

[0073] In equation 2, α2 is a constant, and L2 is the length of the vertical line in the first sub-region.

[0074] Furthermore, the differential information calculation formula in case (2) is not limited to equation 2. The differential information calculation formula in case (2) can be any increasing function with the length of the vertical line (L2) as a parameter.

[0075] Furthermore, if there are multiple vertical lines in the first sub-region, the second pre-processing unit 32 calculates differential information for each vertical line and calculates the sum of the differential information for each vertical line. This sum is the differential information for the first sub-region. (3) When the first sub-region contains n diagonal lines

[0076] The second preprocessing unit 32 processes each of the one or more graphic information items and each of the two or more first subregions, determining the length of each diagonal line (L) within the first subregion. i The second preprocessor unit 32 calculates the angle (α) of the normal of each diagonal line for each of the 1 or more geometric information and each of the 2 or more first subregions. i ) is obtained. Next, the second preprocessing unit 32 adds L for each diagonal line to the following formula 3. i and α iSubstitute the above into the formula 3, execute the formula, and obtain the differential information. Next, for each piece of graphic information of 1 or more and for each of the first small regions of 2 or more, the second preprocessing unit 32 accumulates the differential information in the differential information storage unit 12. The second preprocessing unit 32 accumulates the differential information in the differential information storage unit 12, for example, in association with the graphic identifier and the first small region identifier.

[0077]

Number

[0078] In the formula 3, D x is the information on the area increase amount of the X component. D y is the information on the area increase amount of the Y component. L i is the length of the diagonal line. α i is the angle of the normal line of the diagonal line.

[0079] Also, the differential information calculation formula in the case of (3) is not limited to the formula 3. The differential information calculation formula in the case of (3) may be an increasing function with the length of the diagonal line (L i ) as a parameter.

[0080] Also, the derivation process of the above formula 3 will be described below.

[0081] Even in a case where anisotropic sizing is required, usually, the bias amount changes continuously. That is, in most cases, it is desired to apply a similar bias amount to line segments with similar angles. Therefore, as shown in FIG. 2, the bias amount corresponding to the angle of the line segment is defined by an ellipse. Assume that the bias amounts (B x , B y ) in the X direction (horizontal line) and the Y direction (vertical line) are given. Then, the bias amount (BIAS) is calculated by the formula 4. Note that α is the angle of the normal line with respect to the diagonal line 201 (see FIG. 2).

[0082]

Number

[0083] According to Equation 4, the direction of the bias vector will deviate from the normal direction. However, if the actual bias direction is the normal direction, the area variation can be decomposed into X and Y components as follows (see Equation 5). This is because the user B x ,B y This matches the method of specifying only.

[0084]

number

[0085] In addition, in equation 5, ΔArea x ΔArea is the X component of the area variation. y This is the Y component of the area variation. edge θ is the length of the shaded area 301 in Figure 3. θ in Figure 3 is the angle of the shaded area relative to the horizontal line.

[0086] From the above, if we consider the bias vector obtained by projecting the bias vector given by the elliptic equation in the direction of the normal as the bias vector, then the bias amount is given by the following equation 6.

[0087]

number

[0088] The change in area caused by a straight line of length L can be expressed by the following equation 7.

[0089]

number

[0090] Here, L and α are data specific to the line segment, so L is the length of the i-th diagonal line segment and the angle of its normal, respectively. i , α i Therefore, the area variation for the line segment group can be expressed by the following equation 8 (see Figure 4). Note that in Figure 4, B x =A,B y = 1

[0091]

number

[0092] Therefore, the differential value (differential information) of the total area variation for a group of line segments can be defined as shown in equation 3 above. (4) When the first subregion contains N corners

[0093] The second preprocessor unit 32 obtains all the parameters used in equation 9 for each of the one or more geometric information items, each of the two or more first subregions, and each corner. Next, the second preprocessor unit 32 substitutes all the parameters into equation 9 for each of the one or more geometric information items, each of the two or more first subregions, and each corner, executes equation 9, and obtains differential information. Next, the second preprocessor unit 32 calculates the differential information for each of the one or more geometric information items, each of the two or more first subregions, and each corner, and stores the differential information in the differential information storage unit 12.

[0094] The second preprocessing unit 32 calculates, for example, the sum of one or more derivative information calculated for each of the one or more graphic information items and each of the two or more first sub-regions, and stores this sum of one or more derivative information in the derivative information storage unit 12, associating it with the graphic identifier and the first sub-region identifier. This sum is the derivative information for each of the one or more graphic information items, each of the two or more first sub-regions, and each corner.

[0095]

number

[0096] Note that the first term on the right-hand side of equation 9 is the area of ​​triangle T21. The second term is the area of ​​parallelogram P. The third term is the area of ​​triangle T12. Also, equation 9...

[0097] Furthermore, the derivation process of equation 9 above is explained below.

[0098] Here, we consider the shape of the corner (shaded area, 501, 502, and 503 in Figure 5) obtained by applying biases represented by bias vectors B1 and B2 to the angle formed by line segments L1 and L2, which are represented by two unit vectors as shown in Figure 5.

[0099] Furthermore, U1 represents a vector from a vertex defined by L1 to L2' in the direction of the L1 vector. Similarly, U2 represents a vector from a vertex defined by L2 to L1' in the direction of the L2 vector.

[0100] Here, the angle between L1 and B2 is θ. 12 Therefore, U1 can be expressed as shown in equation 10 below (where L1 is a unit vector).

[0101]

number

[0102] Similarly, U2 can be expressed as shown in equation 11 below (where L2 is a unit vector).

[0103]

number

[0104] Now that U1 and U2 are determined, the increase in the area of ​​the corner is calculated separately for the parallelogram P formed by U1 and U2, triangle T12 formed by U1 and B2, and triangle T21 formed by U2 and B1 (see Figure 6).

[0105] P is calculated using U1 and U2 by the following formula 12.

[0106]

number

[0107] T12 and T21 are also calculated using the cross product, respectively, by formulas 13 and 14.

[0108]

number

[0109]

number

[0110] If we set the components that do not depend on biases B1 and B2 as shown in equation 15, the area of ​​the corners will be as shown in equation 16 below.

[0111]

number

[0112]

number

[0113] Here, the magnitudes of the bias vectors B1 and B2 are given by equation 17, where Φ1 and Φ2 are the angles in the normal direction of L1 and L2.

[0114]

number

[0115] Transforming equation 17 yields equation 18.

[0116]

number

[0117]

number

[0118] Here, as in equation 19, d xx d yy d xyIf we define this, the area of ​​the corner is given by the following formula 20.

[0119]

number

[0120] In equation 20, d xx d yy d xy Since this information is independent of bias and can be calculated solely from geometric information, the sum of the corner areas of a group of figures containing N vertices is given by the above formula 9.

[0121] If a first sub-region contains multiple types of figures, the second pre-processing unit 32 calculates differential information for each type of figure and calculates the sum of the differential information for each type. The second pre-processing unit 32 then stores this sum of differential information in the differential information storage unit 12 as the differential information for the first sub-region. The second preprocessing unit 32 is not limited to the method described above.

[0122] The density set acquisition unit 33 acquires, for example, a first density set corresponding to the graphic information received by the graphic information receiving unit 21 from the density set storage unit 11. The density set acquisition unit 33 acquires, for example, a first density set corresponding to each of two or more graphic information received by the graphic information receiving unit 21 from the density set storage unit 11. Note that such a density set may also be a second density set, as described later. In this case, no correction using a bias amount is performed.

[0123] The density set acquisition unit 33, for example, acquires a first density set from the density set storage unit 11, which is a density set corresponding to the graphic information received by the graphic information receiving unit 21, and uses the first density set to acquire a second density set.

[0124] The density set reading means 331, which constitutes the density set acquisition unit 33, acquires a first density set, which is a density set corresponding to the graphic information received by the reception unit 2, from the density set storage unit 11. The density set reading means 331 acquires a first density set corresponding to each of the two or more graphic information received by the reception unit 2 from the density set storage unit 11.

[0125] The area change information acquisition means 332 acquires area change information based on the shape of the first sub-region from among two or more first sub-regions corresponding to the graphic information received by the reception unit 2, for the first sub-region that matches the bias condition. The bias condition is stored in the storage unit 1.

[0126] The area variation information acquisition means 332 acquires area variation information for a first sub-region that matches the bias condition, using the differential information associated with the first sub-region and the bias amount received by the bias amount receiving unit 22. For example, the area variation information acquisition means 332 acquires the differential information associated with the first sub-region that matches the bias condition from the differential information storage unit 12, and calculates area variation information which is the product of the differential information and the bias amount received by the bias amount receiving unit 22.

[0127] The area variation information acquisition means 332 acquires area variation information, for example, with respect to the horizontal or vertical lines of a figure within the first small region, with a magnitude proportional to the bias amount.

[0128] The area variation information acquisition means 332 acquires the bias amount, angle information relating to the angle of the diagonal line, and length information relating to the length within the first sub-region of the diagonal line. Using the bias amount, angle information, and length information, it calculates the X area variation information, which is the area variation information of the X component, and the Y area variation information, which is the area variation information of the Y component. Using the X area variation information and the Y area variation information, it calculates the area variation information. For example, the area variation information acquisition means 332 calculates the area variation information using an increasing function with the X area variation information and the Y area variation information as parameters. The increasing function is, for example, a sum.

[0129] The area change information acquisition means 332 calculates the area of ​​a parallelogram and two triangles created by extending two straight lines by a length corresponding to the bias amount, and uses these three areas to calculate area change information. The area change information acquisition means 332 calculates the area change information using an increasing function that takes each of the three areas as a parameter. The increasing function is, for example, the sum.

[0130] The density set acquisition means 333 uses the first density set acquired by the density set reading means 331 and the area variation information of one or more first subregions acquired by the area variation information acquisition means 332 to acquire a second density set corresponding to one or more graphic information.

[0131] The density set acquisition means 333 acquires, for example, first density information and area variation information for each of the one or more graphic information items and each of the two or more sub-regions, and acquires second density information for each of the graphic information items and sub-regions using an increasing function with the first density set and area variation information as parameters. Then, for example, the density set acquisition means 333 acquires a second density set for each of the two or more sub-regions, which is a set of second density information. The increasing function is, for example, a sum.

[0132] The correction amount acquisition unit 34 acquires correction amounts corresponding to one or more first density sets for each of the one or more graphic information items, and for each of the two or more second sub-regions. The set of correction amounts for each of the two or more second sub-regions is called a correction amount set or correction map. The correction amount acquisition unit 34 may acquire two or more correction maps. For example, the correction amount acquisition unit 34 may acquire a correction map for each of the two or more types of correction. Types of correction include, for example, ...

[0133] The correction amount acquisition unit 34 acquires correction amounts for two or more second sub-regions using, for example, one or more second density sets. Each second sub-region may be the same as any of the first sub-regions, may contain two or more first sub-regions, may be a part of any of the first sub-regions, or may be a part of two or more first sub-regions, etc. In other words, the relationship between the second sub-regions and the first sub-regions is not relevant. The second sub-regions may be regions of different sizes from the first sub-regions.

[0134] The correction amount acquisition unit 34 may acquire the correction amount for each of the two or more second sub-regions using two or more density sets of graphic information. Note that the density set here may be either the first density set or the second density set.

[0135] The correction amount acquisition unit 34 calculates a correction amount for each second sub-region using an increasing function that takes as a parameter the first density information of one or more first sub-regions corresponding to the second sub-region. The increasing function is, for example, an addition function. The first sub-region corresponding to the second sub-region is a first sub-region that is included in any part of the range of the second sub-region.

[0136] The correction amount acquisition unit 34 preferably acquires correction amounts for two or more second sub-regions using one or more second density sets acquired by the density set acquisition means 333.

[0137] The correction amount acquisition unit 34 calculates a correction amount for each second sub-region using an increasing function that takes the second density information of one or more first sub-regions corresponding to the second sub-region as a parameter. The increasing function is, for example, an addition function.

[0138] The correction amount acquisition unit 34 may also acquire the correction amount for the second sub-region using information other than the first density set or the second density set. For example, the correction amount acquisition unit 34 calculates the correction amount by combining a table of correction amounts for each position, type, and size of a figure calculated in advance, the beam irradiation amount, and parameters of a model that represents phenomena such as a Gaussian kernel in density-dependent phenomena such as development and etching, with the second density set and characteristic information of processes such as Coulomb scattering of the drawing beam and scattering in the sample. For example, the correction amount acquisition unit 34 may acquire a correction amount using the acquired bias amount. The bias amount may be stored in the storage unit 1 beforehand, or it may be received by the receiving unit 2.

[0139] The irradiation dose acquisition unit 35 acquires the irradiation dose of an electron beam with an intensity corresponding to the correction amount of each of the two or more second small regions acquired by the correction amount acquisition unit 34, for each of the two or more second small regions.

[0140] The irradiation dose acquisition unit 35 calculates the irradiation dose for each of the two or more second sub-regions using an increasing function that takes as a parameter the correction amounts for each of the two or more second sub-regions acquired by the correction amount acquisition unit 34.

[0141] The irradiation dose acquisition unit 35 may determine the irradiation dose using information other than the correction amount for each second sub-region. For example, the irradiation dose acquisition unit 35 may determine the irradiation dose by combining the correction amount for the second sub-region with the correction amount for the second sub-region and the correction amount for the second sub-region that is equivalent to or smaller than the influence range of the second sub-region or a correction amount pre-assigned to each shape. This phenomenon is, for example, the proximity effect caused by electron beam irradiation.

[0142] The drawing unit 36 ​​irradiates two or more second small regions with an electron beam according to the irradiation dose for each of the two or more second small regions acquired by the irradiation dose acquisition unit 35. The irradiation dose for each second small region is the irradiation dose acquired by the irradiation dose acquisition unit 35. The object to be drawn is, for example, a photomask or a wafer. The drawing unit 36 ​​can usually be realized from an electron gun such as a field emission type, Schottky type, or thermionic type, as well as an electron lens, height detector, etc. The cross-sectional shape of the electron beam emitted by the drawing unit 36 ​​is, for example, a rectangle or a circle. The drawing unit 36 ​​may also draw a figure using multiple beams simultaneously. Furthermore, it is preferable for the drawing unit 36 ​​to apply bias processing to one or more graphic information received by the graphic information receiving unit 21 to obtain biased graphic information. The irradiation dose acquisition unit 35 then uses the biased graphic information and the correction amounts for each of the two or more second sub-regions acquired by the correction amount acquisition unit 34 to acquire the irradiation dose of the electron beam for each of the two or more second sub-regions. Specifically, correction is mainly performed to consider scattering in a narrower range of the electron beam. The calculation using the density information of the second sub-region is usually for an influence range on the order of millimeters, but the calculation performed in real time during drawing is for an influence range of tens of micrometers or hundreds of nanometers (in some cases, about 10 nm). The irradiation dose acquisition unit 35 inputs the "correction amount" of the second sub-region into a pre-stored calculation formula corresponding to this phenomenon and acquires the irradiation dose by executing the calculation formula. Next, the drawing unit 36 ​​irradiates each of the two or more second sub-regions with the electron beam according to the irradiation dose for each of the two or more second sub-regions acquired by the irradiation dose acquisition unit 35 to draw the graphic.

[0143] Output unit 4 outputs various types of information. These types of information include, for example, information indicating that the drawing of a figure has been completed. Here, output is a concept that includes displaying on a screen, projecting using a projector, printing with a printer, sound output, transmission to an external device, storage on a recording medium, and handing over processing results to other processing devices or other programs.

[0144] The storage unit 1, density aggregation storage unit 11, and differential information storage unit 12 are preferably made of non-volatile recording media, but can also be made of volatile recording media.

[0145] The process by which information is stored in the storage unit 1, etc. is not relevant. For example, information may be stored in the storage unit 1, etc. via a recording medium, information transmitted via a communication line, etc. may be stored in the storage unit 1, etc., or information input via an input device may be stored in the storage unit 1, etc.

[0146] The reception unit 2 and the graphic information reception unit 21 can be implemented using device drivers for input means such as touch panels and keyboards, or control software for menu screens.

[0147] The bias amount receiving unit 22, processing unit 3, first pre-processing unit 31, second pre-processing unit 32, density set acquisition unit 33, correction amount acquisition unit 34, irradiation amount acquisition unit 35, density set reading means 331, area variation information acquisition means 332, and density set acquisition means 333 can usually be implemented using a processor, memory, etc. The processing procedures of the processing unit 3, etc., are usually implemented in software, and this software is recorded on a recording medium such as ROM. However, it may also be implemented in hardware (dedicated circuitry). The processor can be, for example, a CPU, MPU, GPU, etc., and the type is not limited.

[0148] The output unit 4 may or may not include output devices such as displays and speakers. The output unit 4 can be implemented using driver software for the output device, or using driver software for the output device and the output device itself.

[0149] The processing procedure of the drawing unit 36 ​​is usually implemented by software, and this software is recorded on a recording medium such as ROM.

[0150] Next, an example of the operation of electron beam lithography apparatus A will be explained using the flowchart in Figure 7.

[0151] (Step S701) The reception unit 2 determines whether or not it has received a pre-processing instruction. If a pre-processing instruction has been received, the process proceeds to step S702; otherwise, the process proceeds to step S716.

[0152] (Step S702) Processing unit 3 assigns 1 to counter i.

[0153] (Step S703) The first preprocessing unit 31 determines whether or not the i-th graphic information to be preprocessed exists. If the i-th graphic information exists, the process proceeds to step S704; otherwise, the process returns to step S701. The graphic information to be preprocessed is stored in the storage unit 1, for example, associated with a graphic identifier.

[0154] (Step S704) The first preprocessing unit 31 obtains the i-th graphic information and graphic identifier from, for example, the storage unit 1.

[0155] (Step S705) The first preprocessing unit 31 divides the region containing the i-th graphic information into two or more subregions. Each subregion is referred to as the first subregion. The process of dividing into two or more subregions is the process of obtaining region information for each of the two or more first subregions in conjunction with the region identifier. The region identifier is information that identifies the region (in this case, the first subregion), for example, an ID. The region information is information that identifies the region of a rectangle, for example, two pieces of coordinate information (for example, (x1, y1)(x2, y2)). The two pieces of coordinate information are, for example, the top-left coordinate and the bottom-right coordinate of the rectangle. However, the region information may also be, for example, the top-left coordinate and information on the width and height of the rectangle, and the structure is not restricted.

[0156] (Step S706) The first preprocessing unit 31 assigns 1 to counter j.

[0157] (Step S707) The first preprocessing unit 31 determines whether the j-th first subregion exists in the i-th graphic information. If the j-th first subregion exists, the unit proceeds to step S708; otherwise, the unit proceeds to step S715.

[0158] (Step S708) The first preprocessing unit 31 obtains the first sub-region identifier, which is the identifier of the j-th first sub-region in the i-th graphic information.

[0159] (Step S709) The first preprocessing unit 31 obtains region information for the jth first subregion within the i-th graphic information.

[0160] (Step S710) The first preprocessing unit 31 acquires the first density information of the j-th first sub-region within the i-th graphic information. An example of such density information acquisition process will be explained using the flowchart in Figure 8.

[0161] (Step S711) The first preprocessing unit 31 associates the graphic identifier of the i-th graphic information with the first sub-region identifier of the j-th first sub-region and stores the density information obtained in step S710. The storage location for the density information may be the storage unit 1 or an external device not shown.

[0162] (Step S712) The second preprocessing unit 32 acquires differential information. An example of this differential information acquisition process will be explained using the flowchart in Figure 9.

[0163] (Step S713) The second preprocessing unit 32 associates the shape identifier of the i-th shape information with the first sub-region identifier of the j-th first sub-region and stores the differential information obtained in step S712. The storage location for the differential information may be the storage unit 1 or an external device not shown.

[0164] (Step S714) The first preprocessing unit 31 increments counter j by 1. Return to step S707.

[0165] (Step S715) Processing unit 3 increments counter i by 1. Return to step S703.

[0166] (Step S716) The reception unit 2 determines whether or not it has received the start instruction. If it has received the start instruction, it proceeds to step S717; otherwise, it returns to step S701.

[0167] (Step S717) Processing unit 3 assigns 1 to counter i.

[0168] (Step S718) The density set acquisition unit 33 determines whether or not the i-th figure information to be drawn exists. If the i-th figure information exists, the process proceeds to step S704; otherwise, the process returns to step S701. The figure information to be drawn is stored in the storage unit 1, for example, associated with a figure identifier. The figure information to be drawn is also contained in, for example, the start instruction.

[0169] (Step S719) The bias amount receiving unit 22 acquires the bias amount. Note that the bias amount may differ depending on the graphic information. Also, the bias amount may differ depending on the shape in the graphic information.

[0170] (Step S720) The density set acquisition unit 33 acquires a second density set. An example of this density set acquisition process will be explained using the flowchart in Figure 10.

[0171] (Step S721) Processing unit 3 increments counter i by 1. Return to step S718.

[0172] (Step S722) The correction amount acquisition unit 34 acquires a set of correction amounts. An example of acquiring such a set of correction amounts will be explained using the flowchart in Figure 11.

[0173] (Step S723) The drawing unit 36 ​​performs drawing processing using the set of correction amounts obtained in step S722. The process returns to step S701. An example of the drawing process will be explained using the flowchart in Figure 12.

[0174] In the flowchart shown in Figure 7, processing is terminated by power-off or processing termination interrupts.

[0175] Next, an example of the density information acquisition process in step S710 will be explained using the flowchart in Figure 8.

[0176] (Step S801) The first preprocessing unit 31 obtains the area of ​​the j-th sub-region within the i-th graphic information (for example, referred to as the first area). This area is stored, for example, in the storage unit 1. This area can also be obtained from the area information of the j-th sub-region.

[0177] (Step S802) The first preprocessing unit 31 obtains the area occupied by the figure within the j-th sub-region in the i-th figure information (for example, referred to as the second area). Normally, the first preprocessing unit 31 calculates the area occupied by the figure within the j-th sub-region using the region information and figure information of the j-th sub-region. This technique is publicly known.

[0178] (Step S803) The first preprocessing unit 31 calculates the first density information using the first area obtained in step S801 and the second area obtained in step S802. It then returns to the higher-level processing unit.

[0179] The first preprocessing unit 31 calculates density information, for example, using the formula "density information = second area / first area". Alternatively, the first preprocessing unit 31 may use the second area as the density information. The density information only needs to be information that identifies how much of the figure is contained within the j-th sub-region.

[0180] Next, an example of the differential information acquisition process in step S712 will be explained using the flowchart in Figure 9.

[0181] (Step S901) The second preprocessing unit 32 assigns 1 to counter i.

[0182] (Step S902) The second preprocessor unit 32 determines whether the i-th bias condition exists in the storage unit 1. If the i-th bias condition exists, the process proceeds to step S903; otherwise, the process proceeds to step S913.

[0183] (Step S903) The second preprocessing unit 32 obtains the i-th bias condition from the storage unit 1.

[0184] (Step S904) The second preprocessing unit 32 acquires the graphic information within the target sub-region of the target graphic information.

[0185] (Step S905) The second preprocessing unit 32 uses the graphic information within the small region to detect the graphic in the small region that matches the i-th bias condition.

[0186] (Step S906) The second preprocessing unit 32 obtains the differential information calculation formula corresponding to the i-th bias condition from the storage unit 1.

[0187] (Step S907) The second preprocessing unit 32 assigns 1 to counter j.

[0188] (Step S908) The second preprocessor unit 32 determines whether or not the j-th figure exists among the figures detected in step S905. If the j-th figure exists, the process proceeds to step S909; otherwise, the process proceeds to step S912.

[0189] (Step S909) The second preprocessing unit 32 obtains one or more parameters to be substituted into the differential information calculation formula obtained in step S906, using the information of the j-th figure of the geometric information of the small region to be processed. The one or more parameters are, for example, the length of the diagonal lines within the small region, the angle of the diagonal lines within the small region, and the angle of the corners within the small region.

[0190] (Step S910) The second preprocessor 32 substitutes one or more parameters obtained in step S909 into the differential information calculation formula obtained in step S906, executes the differential information calculation formula, obtains differential information, and stores it in a buffer (not shown).

[0191] (Step S911) The second preprocessing unit 32 increments counter j by 1. The process returns to step S908.

[0192] (Step S912) The second preprocessor unit 32 increments counter i by 1. The process returns to step S902.

[0193] (Step S913) The second preprocessing unit 32 calculates the sum of the differential information accumulated in the buffer in step S910. This sum of differential information is the differential information of the first subregion of interest. If no differential information has been accumulated in the buffer in step S910, the differential information is "0".

[0194] Next, an example of the density set acquisition process in step S720 will be explained using the flowchart in Figure 10.

[0195] (Step S1001) The density set acquisition unit 33 assigns 1 to counter i.

[0196] (Step S1002) The density set reading means 331 determines whether or not the i-th first sub-region exists in the graphic information to be processed. If the i-th first sub-region exists, the process proceeds to step S1003; otherwise, the process returns to the higher level.

[0197] (Step S1003) The density set reading means 331 obtains first density information from the density set storage unit 11 that is paired with the graphic identifier of the graphic information to be processed and the first sub-region identifier of the i-th first sub-region.

[0198] (Step S1004) The area variation information acquisition means 332 acquires differential information from the differential information storage unit 12 that is paired with the shape identifier of the shape information to be processed and the first sub-region identifier of the i-th first sub-region.

[0199] (Step S1005) The area variation information acquisition means 332 acquires area variation information using the bias amount acquired by the bias amount receiving unit 22 and the differential information acquired in step S1004. The area variation information acquisition means 332 calculates the area variation information, for example, using the calculation formula "area variation information = bias amount × differential information".

[0200] (Step S1006) The density set acquisition unit 33 uses the first density information acquired in step S1003 and the area variation information acquired in step S1005 to acquire the second density information of the i-th first subregion of the geometric information to be processed. The density set acquisition unit 33 calculates the second density information, for example, using the calculation formula "second density information = first density information + area variation information".

[0201] (Step S1007) The density set acquisition unit 33 stores the second density information acquired in step S1006, associating it with the graphic identifier of the graphic information to be processed and the first sub-region identifier of the i-th first sub-region. The storage location of the second density information is, for example, the storage unit 1, but is not limited to that.

[0202] (Step S1008) The density set acquisition unit 33 increments the counter i by 1. Return to step S1002.

[0203] Next, an example of obtaining the correction amount set in step S722 will be explained using the flowchart in Figure 11.

[0204] (Step S1101) The correction amount acquisition unit 34 assigns 1 to counter i.

[0205] (Step S1102) The correction amount acquisition unit 34 determines whether the i-th second sub-region exists. If the i-th second sub-region exists, the process proceeds to step S1103; otherwise, the process returns to the higher-level processing.

[0206] (Step S1103) The correction amount acquisition unit 34 assigns 1 to counter j.

[0207] (Step S1104) The correction amount acquisition unit 34 determines whether or not the j-th figure information to be drawn exists. If the j-th figure information exists, the unit proceeds to step S1105; if the j-th figure information does not exist, the unit proceeds to step S1113.

[0208] (Step S1105) The correction amount acquisition unit 34 substitutes the counter k1.

[0209] (Step S1106) The correction amount acquisition unit 34 determines whether or not the kth first region corresponding to the ith second subregion exists. If the kth first region exists, the unit proceeds to step S1107; if the kth first region does not exist, the unit proceeds to step S1111.

[0210] (Step S1107) The correction amount acquisition unit 34 acquires the second density information of the k-th first region.

[0211] (Step S1108) The correction amount acquisition unit 34 acquires the proportion of the k-th first region that is included in the i-th second sub-region.

[0212] (Step S1109) The correction amount acquisition unit 34 calculates the contribution using the second density information acquired in step S1107 and the ratio acquired in step S1108. The contribution is information indicating the degree of contribution of the correction amount of the k-th first region to the i-th second sub-region. The correction amount acquisition unit 34 calculates the contribution using, for example, the calculation formula "Contribution = Second Density Information × Ratio".

[0213] (Step S1110) The correction amount acquisition unit 34 increments the counter k by 1. Return to step S1106.

[0214] (Step S1111) The correction amount acquisition unit 34 calculates the correction amount source information for the j-th figure in the i-th second sub-region using the contribution values ​​of 1 or more calculated in step S1109. The correction amount source information is calculated by an increasing function with each contribution value of 1 or more as a parameter. The correction amount source information is, for example, the sum of the contribution values ​​of 1 or more.

[0215] (Step S1112) The correction amount acquisition unit 34 increments counter j by 1. Return to step S1104.

[0216] (Step S1113) The correction amount acquisition unit 34 calculates the correction amount for the i-th second sub-region using the one or more correction amount source information calculated in step S1111. The correction amount acquisition unit 34 calculates the correction amount using an increasing function that takes each of the one or more correction amount source information as a parameter. For example, the correction amount acquisition unit 34 calculates the correction amount using the calculation formula "Correction amount = sum of one or more correction amount source information".

[0217] (Step S1114) The correction amount acquisition unit 34 stores the correction amount calculated in step S1113, associating it with the second sub-region identifier of the i-th second sub-region. The storage destination of the correction amount is, for example, the storage unit 1, but is not limited to that.

[0218] (Step S1115) The correction amount acquisition unit 34 increments counter i by 1. Return to step S1102.

[0219] Next, an example of the drawing process in step S723 will be explained using the flowchart in Figure 12.

[0220] (Step S1201) The drawing unit 36 ​​assigns 1 to counter i.

[0221] (Step S1202) The drawing unit 36 ​​determines whether or not the i-th second sub-region for drawing the shape exists. If the i-th second sub-region exists, the process proceeds to step S1203; otherwise, the process returns to the higher level.

[0222] (Step S1203) The drawing unit 36 ​​obtains a correction amount that is paired with the second sub-region identifier of the i-th second sub-region. The drawing unit 36 ​​reads, for example, the correction amount that is paired with the second sub-region identifier of the i-th second sub-region from the storage unit 1.

[0223] (Step S1204) The drawing unit 36 ​​calculates the irradiation amount using the correction amount obtained in step S1203. The drawing unit 36 ​​calculates the irradiation amount using, for example, an increasing function with the correction amount as a parameter.

[0224] (Step S1205) The drawing unit 36 ​​irradiates the i-th second sub-region with an electron beam according to the irradiation dose calculated in step S1204.

[0225] (Step S1206) The drawing unit 36 ​​increments counter i by 1. Return to step S1202.

[0226] The following describes specific examples of the operation of electron beam lithography apparatus A in this embodiment. Two specific examples are described below.

[0227] (Specific example 1) Specific Example 1 is a first example of preprocessing for electron beam lithography system A, and is an example of the process for obtaining a density set (density map).

[0228] Now, let's assume that graphic information identifying the three rectangular shapes shown in Figure 13(a) is stored in the storage unit 1 of the electron beam lithography apparatus A. For example, the graphic information in Figure 13(a) is (x1,y1)(x2,y2) for shape 1301, (x3,y3)(x4,y4) for shape 1302, and (x5,y5)(x6,y6) for shape 1303.

[0229] The user then inputs pre-processing instructions to electron beam lithography apparatus A. Next, reception unit 2 receives the pre-processing instructions.

[0230] Next, the first preprocessing unit 31 divides the region containing the graphic information in Figure 13(a) into two or more subregions (see Figure 13(b)). Each subregion is referred to as the first subregion. The first preprocessing unit 31 then obtains the subregion information (top-left coordinate and bottom-right coordinate of the rectangle) for each first subregion in Figure 13(b). Examples of first subregions are 1304 and 1305 in Figure 13.

[0231] Next, the first preprocessing unit 31 calculates the area occupied by the shape within each first sub-region using the region information and shape information of each first sub-region. The first preprocessing unit 31 also obtains the area of ​​each first sub-region from the region information of the first sub-region. Alternatively, the first preprocessing unit 31 may read the area of ​​each first sub-region from the storage unit 1.

[0232] Next, the first preprocessing unit 31 calculates density information for each first sub-region using the area occupied by the shape of each first sub-region and the area of ​​each first sub-region. The first preprocessing unit 31 calculates density information, for example, using the formula "density information = area occupied by the shape of the first sub-region / area of ​​the first sub-region".

[0233] The first preprocessing unit 31 then associates the graphic identifier that identifies the graphic information with the first sub-region identifier of each first sub-region and stores the first density information in the density set storage unit 11. An example of the first density map, which is a collection of such first density information, is shown in Figure 14. In Figure 14, there are many records that have "ID", "graphic identifier", "first sub-region identifier", "first sub-region information", and "first density information". Figure 13(c) is a graphical representation of the first density map in Figure 14.

[0234] Furthermore, the first density map in Figure 14 is used to create a set of correction amounts (correction map) that is generated when drawing the shape, as explained using the flowchart in Figure 7. The image of the correction map is shown in Figure 13(d). In addition, as explained using the flowchart in Figure 7, the irradiation amount for each second sub-region is determined using the correction map, and the electron beam is irradiated according to that irradiation amount.

[0235] In summary, by preparing a density map in advance, the drawing of shapes using an electron beam becomes extremely fast.

[0236] (Specific example 2) Specific example 2 is a first example of preprocessing for electron beam lithography apparatus A, which involves acquiring differential information for each first sub-region and using that differential information to acquire a density set (density map).

[0237] Now, assume that graphic information having three rectangular graphics shown in FIG. 15(a) is stored in the storage unit 1 of the electron beam lithography apparatus A. The graphic information in FIG. 15(a) is, for example, the graphic information (x1, y1)(x2, y2) of graphic 1501, the graphic information (x3, y3)(x4, y4) of graphic 1502, and the graphic information (x5, y5)(x6, y6) of graphic 1503.

[0238] And assume that the user inputs a preprocessing instruction to the electron beam lithography apparatus A. Next, the reception unit 2 receives the preprocessing instruction.

[0239] Next, the first preprocessing unit 31 obtains a first density map 1504 having first density information for each of two or more first small regions by the process described in Specific Example 1.

[0240] Next, as described using the flowchart of FIG. 9, the second preprocessing unit 32 obtains a differential information calculation formula corresponding to a bias condition in which the graphic information in each of two or more first small regions matches, obtains one or more parameters to be substituted into the differential information calculation formula from the graphic information, substitutes the one or more parameters into the differential information calculation formula, and calculates differential information by executing the differential information calculation formula. Then, the second preprocessing unit 32 accumulates the differential information for each graphic information and for each first small region in the differential information storage unit 12.

[0241] An example of such a differential information set is shown in FIG. 16. In FIG. 16, there are a number of records having "ID", "Graphic Identifier", "First Small Region Identifier", "First Small Region Information", and "Differential Information". Note that the differential information "d1", "d2", "d3", "d4", etc., in FIG. 16 are numerical values.

[0242] The differential information set in FIG. 16 is used for creating a correction amount set (correction map) created when drawing a figure, as described using the flowchart of FIG. 7. That is, as described using the flowchart of FIG. 10, using the first density map 1504 created by the first preprocessing unit 31 and the differential information for each first small region acquired by the second preprocessing unit 32 (see FIG. 15(c)), the second density information for each first small region shown in FIG. 15(d) is acquired. Note that the set of the second density information for two or more first small regions is the second density map.

[0243] Then, as described using the flowchart of FIG. 7, using the second density information (second density map) for each first small region shown in FIG. 15(d), a correction amount set (correction map) created when drawing a figure is created. Also, the image of the correction map is shown in FIG. 15(e). Further, as described using the flowchart of FIG. 7, using the correction map, the irradiation amount of each second small region is determined, and according to the irradiation amount, an electron beam is irradiated.

[0244] By preparing the differential information set in advance as described above, the drawing of a figure by an electron beam becomes very fast.

[0245] As described above, according to the present embodiment, an appropriate irradiation amount when drawing a figure using an electron beam can be acquired at high speed.

[0246] In the present embodiment, the device for creating the first density map may be configured as a device different from the electron beam drawing device. A block diagram of the density set production device B, which is such a device in this case, is shown in FIG. 17.

[0247] The density set production device B includes a graphic information reception unit 21 that receives one or more pieces of graphic information, and for each of two or more first small regions obtained by dividing the graphic region, which is the region specified by the graphic information, within each of the two or more first small regions, first density information based on the area of the figure shown in the graphic information is acquired, and a first preprocessing unit 31 that acquires and accumulates a first density set, which is a set of the first density information, for each of one or more pieces of graphic information.

[0248] Furthermore, in this embodiment, the apparatus for creating the differential information set may be configured as a separate apparatus from the electron beam lithography apparatus. Figure 18 shows a block diagram of the differential information set production apparatus C in such a case.

[0249] The differential information set production device C comprises a graphic information receiving unit 21 that receives one or more graphic information, and a second preprocessing unit 32 that calculates and stores differential information that identifies the variation in area relative to a unit quantity of bias for each of the one or more graphic information and for each of the two or more first sub-regions.

[0250] Furthermore, the processing in this embodiment may be implemented in software. This software may be distributed via software download or the like. Alternatively, this software may be recorded on a recording medium such as a CD-ROM and distributed. This also applies to other embodiments described herein. The software that implements the electron beam lithography apparatus A in this embodiment is the following program. In other words, this program is a program to enable a computer that can access a density set storage unit in which a first density set, which is a set of first density information corresponding to the area in which the figure indicated by the figure information is contained within each of two or more first sub-regions obtained by dividing the figure region specified by the figure information, is stored for each of the two or more first sub-regions, to function as a drawing unit that receives one or more figure information, a figure information receiving unit that receives one or more figure information, a density set acquisition unit that acquires a first density set corresponding to each of the one or more figure information received by the figure information receiving unit from the density set storage unit, a correction amount acquisition unit that acquires a correction amount corresponding to the one or more first density sets for each of the one or more figure information, and a correction amount acquisition unit that acquires a correction amount for each of the two or more second sub-regions, which is a correction amount corresponding to the one or more first density sets for each of the one or more figure information, an irradiation amount acquisition unit that acquires an irradiation amount of an electron beam of strength corresponding to the correction amount of each of the two or more second sub-regions acquired by the correction amount acquisition unit, for each of the two or more second sub-regions, and a drawing unit that irradiates each of the two or more second sub-regions with an electron beam according to the irradiation amount for each of the two or more second sub-regions acquired by the irradiation amount acquisition unit.

[0251] Figure 19 also shows the appearance of a computer that executes the program described herein to realize the electron beam lithography apparatus A of the various embodiments described above. The embodiments described above can be realized with computer hardware and computer programs executed thereon. Figure 19 is an overview of this computer system 300, and Figure 20 is a block diagram of the system 300.

[0252] In Figure 19, the computer system 300 includes a computer 301 with a CD-ROM drive, a keyboard 302, a mouse 303, and a monitor 304.

[0253] In Figure 20, the computer 301 includes, in addition to the CD-ROM drive 3012, an MPU 3013, a bus 3014 connected to the CD-ROM drive 3012, a ROM 3015 for storing programs such as boot-up programs, a RAM 3016 connected to the MPU 3013 for temporarily storing instructions for application programs and providing temporary storage space, and a hard disk 3017 for storing application programs, system programs, and data. Although not shown here, the computer 301 may further include a network card that provides connectivity to a LAN.

[0254] The program that causes the computer system 300 to perform the functions of the electron beam lithography apparatus A of the above-described embodiment may be stored on CD-ROM 3101, inserted into CD-ROM drive 3012, and then transferred to hard disk 3017. Alternatively, the program may be transmitted to computer 301 via a network (not shown) and stored on hard disk 3017. The program is loaded into RAM 3016 during execution. The program may also be loaded directly from CD-ROM 3101 or the network.

[0255] The program does not necessarily have to include an operating system (OS) or third-party program that causes the computer 301 to execute the functions of the electron beam lithography apparatus A of the above-described embodiment. The program only needs to include the instruction portion that calls the appropriate function (module) in a controlled manner and obtains the desired result. How the computer system 300 operates is well known, so a detailed explanation is omitted.

[0256] In the above program, steps such as sending information and receiving information do not include hardware-based processing, such as processing performed by a modem or interface card in the transmission step (processing that can only be performed by hardware).

[0257] Furthermore, the computer running the above program may be a single computer or multiple computers. In other words, it may perform centralized processing or distributed processing.

[0258] Furthermore, it goes without saying that in each of the above embodiments, two or more communication means present in a single device may be physically implemented in a single medium.

[0259] Furthermore, in each of the above embodiments, each process may be implemented by centralized processing by a single device, or by distributed processing by multiple devices.

[0260] It goes without saying that the present invention is not limited to the embodiments described above, and various modifications are possible, all of which are also included within the scope of the present invention. [Industrial applicability]

[0261] As described above, the electron beam lithography apparatus according to the present invention has the effect of being able to quickly acquire the appropriate irradiation amount when drawing a figure using an electron beam, and is useful as an electron beam lithography apparatus, etc. [Explanation of symbols]

[0262] 1 Storage section 11 Density set storage section 2 Reception section 3 Processing section 4 Output section 11 Density set storage section 12 Differential information storage section 21 Graphic information reception section 22 Bias amount reception section 31 First preprocessing section 32 Second preprocessing section 33 Density set acquisition section 34 Correction amount acquisition section 35 Irradiation amount acquisition section 36 Drawing section 331 Density set reading means 332 Area variation information acquisition means

Claims

1. A density set storage unit stores a first density set for each of the two or more first sub-regions, each containing a first density set corresponding to the area in which the figure indicated by the figure information is included, for each of the two or more first sub-regions, which is a first density set for each of the two or more first sub-regions, for each of the one or more pieces of figure information. A graphic information receiving unit that receives one or more graphic information, A density set acquisition unit acquires a first density set corresponding to each of the one or more graphic information received by the graphic information receiving unit from the density set storage unit, A correction amount acquisition unit that acquires correction amounts for each of the 1 or more graphic information items corresponding to the 1 or more first density sets, and for each of the 2 or more second subregions, An irradiation dose acquisition unit acquires, for each of the two or more second small regions, the irradiation dose of an electron beam with an intensity corresponding to the correction amount of each of the two or more second small regions acquired by the correction amount acquisition unit, The system comprises a drawing unit that irradiates each of the two or more second small regions with an electron beam according to the irradiation amount for each of the two or more second small regions acquired by the irradiation amount acquisition unit, The density aggregation acquisition unit, A density set reading means for obtaining a first density set corresponding to each of the one or more graphic information received by the graphic information receiving unit from the density set storage unit, Area variation information acquisition means for detecting, among the two or more first sub-regions, a first sub-region that matches the bias condition, which is a condition for acquiring area variation information with respect to the shape of the first sub-region, and acquiring area variation information based on the shape within that first sub-region, The system comprises a density set acquisition means that acquires a second density set, which is a set of second density information for each of the one or more graphic information, for each of the one or more graphic information, using the first density information for each of the one or more first sub-regions in the first density set acquired by the density set reading means and the area variation information for each of the one or more first sub-regions acquired by the area variation information acquisition means. The correction amount acquisition unit, Using one or more second density sets acquired by the density set acquisition means, the correction amounts for two or more second sub-regions are acquired. For each of the two or more bias conditions, different differential information calculation formulas are stored to calculate differential information. A second preprocessing unit obtains a differential information calculation formula corresponding to the matching bias condition for each of the one or more graphic information items and each of the two or more first sub-regions, and calculates differential information using the differential information calculation formula. It further comprises a bias amount receiving unit that accepts a bias amount, The means for acquiring area change information is, An electron beam lithography apparatus that, for a first small region that matches the bias conditions, acquires area variation information for each of the one or more graphic information items using the differential information acquired by the second preprocessing unit and the bias amount received by the bias amount receiving unit.

2. The two or more bias conditions are, The first sub-region contains two or more of the following conditions: the region containing the figure and the region not containing the figure exist; the first sub-region contains the boundary line of the figure; the first sub-region contains the horizontal line of the drawing; the first sub-region contains the vertical line of the drawing; the first sub-region contains the diagonal line of the drawing; and the first sub-region contains the corner of the drawing. The electron beam lithography apparatus according to claim 1, wherein different differential information calculation formulas are stored for each of the two or more bias conditions among the following: the existence of a region containing a figure and a region not containing a figure within the first sub-region; the existence of a boundary line of a figure within the first sub-region; the existence of a horizontal line of a drawing within the first sub-region; the existence of a vertical line of a drawing within the first sub-region; the existence of a diagonal line of a drawing within the first sub-region; and the existence of a corner of a drawing within the first sub-region.

3. The electron beam lithography apparatus according to claim 1 or claim 2, further comprising a first preprocessing unit which acquires, for each of the two or more first sub-regions obtained by dividing the graphic region which is a region specified by the graphic information, first density information based on the area in which the graphic information indicates the graphic is contained within each of the two or more first sub-regions, and acquires a first density set which is a collection of said first density information for each of the one or more graphic information, and stores it in the density set storage unit.

4. The aforementioned drawing unit is The graphic information receiving unit applies a biasing process to the one or more graphic pieces of information it receives, and obtains information on the biased graphic. The irradiation dose acquisition unit, Using the information of the biased figure and the correction amounts of the two or more second small regions acquired by the correction amount acquisition unit, the electron beam irradiation amount of the two or more second small regions is acquired. The electron beam lithography apparatus according to any one of claims 1 to 3, wherein the drawing unit irradiates each of the two or more second small regions with an electron beam according to the irradiation amount for each of the two or more second small regions acquired by the irradiation amount acquisition unit to draw a figure.

5. An electron beam lithography method comprising causing a computer to perform the processing performed by the electron beam lithography apparatus described in any one of claims 1 to 4.

6. Computers, A program for causing an electron beam lithography apparatus to function as described in any one of claims 1 to 4.

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