Drawing data generation method, drawing data generation device, charged particle beam drawing method, charged particle beam drawing device, and program

Abstract

To perform mesh area calculation of a diagram including a curve accurately at high speed.SOLUTION: A drawing data generation method according to an aspect of the present invention generates drawing data used in a charged particle beam drawing device, and the method includes: for a diagram pattern included in design data, dividing a curve surrounding the diagram pattern to generate a plurality of divided curves with a predetermined size or less, and calculating a plurality of control points for parametric curve representation of each divided curve; calculating the feature quantity of a curve part that is surrounded by a parametric curve and a line segment connecting a starting point and an end point of the parametric curve, of the plurality of control points; and generating the drawing data including position information of the plurality of control points and the feature quantity of the curve part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a drawing data generation method, a drawing data generation apparatus, a charged particle beam drawing method, a charged particle beam drawing apparatus, and a program.

Background Art

[0002] With the high integration of LSIs, the circuit line widths required for semiconductor devices have been continuously miniaturized year by year. In order to form a desired circuit pattern on a semiconductor device, a method of reducing and transferring a high-precision original pattern formed on quartz onto a wafer using a reduction projection exposure apparatus is adopted. For the production of a high-precision original pattern, a so-called electron beam lithography technique, in which a resist is exposed by an electron beam drawing apparatus to form a pattern, is used.

[0003] In electron beam drawing, the so-called proximity effect, in which pattern dimensional variations are caused by backscattered electrons, becomes a problem. As one method of correcting the proximity effect, an exposure dose correction method is known. This is a correction method in which the exposure dose is determined for each position based on the size and density of the surrounding patterns at the beam irradiation position.

[0004] In exposure dose correction, the calculation of the backscattered irradiation dose, which occurs when the electron beam irradiated on the photomask is reflected by the mask and re-exposes the resist, is performed. For this calculation, area information, centroid information, etc., in which the pattern information in the layout is represented by a mesh of, for example, 100 nm squares, are used. The electron beam drawing apparatus calculates the coverage (area ratio) and centroid of the input figure for each mesh region partitioned into a predetermined size.

[0005] When expressing the curves included in the input figure using high-degree parametric curves such as cubic B-spline curves or cubic Bézier curves, if the coverage rate and the calculation of the centroid are performed analytically, the amount of calculation increases compared to the calculation for conventional polygons and trapezoids. By approximating the input figure including curves with polygons, the coverage rate can be calculated relatively easily. However, when performing the approximation with high accuracy, there is a problem that the number of vertices of the approximated polygon increases and the amount of calculation increases similarly.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a drawing data generation method, apparatus, and program for generating drawing data for calculating the mesh area of a figure including curves quickly and accurately, and a charged particle beam drawing method and apparatus capable of calculating the mesh area of a figure including curves quickly and accurately.

Means for Solving the Problems

[0008] A drawing data generation method according to an aspect of the present invention is a drawing data generation method for generating drawing data used in a charged particle beam drawing apparatus, and for a figure pattern included in design data, dividing a curve surrounding the figure pattern so as to be below a predetermined size to generate a plurality of divided curves, calculating a plurality of control points for parametric curve representation of each divided curve, calculating a feature amount of a curve portion surrounded by the parametric curve and a line segment connecting the start point and the end point of the parametric curve among the plurality of control points, and generating the drawing data including the position information of the plurality of control points and the feature amount of the curve portion.

[0009] A drawing data generation device according to an aspect of the present invention is a drawing data generation device that generates drawing data used in a charged particle beam drawing device, and includes an input unit to which design data including a graphic pattern is input, and for the graphic pattern included in the design data input to the input unit, a division processing unit that divides a curve surrounding the graphic pattern so as to be a predetermined size or less to generate a plurality of divided curves, a control point calculation unit that calculates a plurality of control points that parametrically represent each divided curve, a feature amount calculation unit that calculates a feature amount of a curved portion surrounded by the parametric curve and a line segment connecting the start point and the end point of the parametric curve among the plurality of control points, and a generation unit that generates the drawing data including position information of the plurality of control points and the feature amount of the curved portion.

[0010] A charged particle beam drawing method according to an aspect of the present invention is a charged particle beam drawing method in which, for a graphic pattern to be drawn, position information of control points of each of a plurality of parametric curves surrounding the graphic pattern and area information of a curved portion surrounded by the parametric curve and a line segment connecting the start point and the end point of the parametric curve are read from a storage device, a drawing area is virtually divided into a plurality of mesh areas with a predetermined size, an area value of the graphic pattern arranged in each mesh area is calculated using the drawing data, and a charged particle beam irradiation amount with proximity effect corrected is calculated using the area value, and the area value of the curved portion is allocated to a mesh area including the centroid of the curved portion.

[0011] According to one aspect of the present invention, a charged particle beam lithography apparatus reads out from a storage device drawing data including, for a graphic pattern to be drawn, position information of control points of each of a plurality of parametric curves surrounding the graphic pattern, and area information of a curved portion surrounded by a line segment connecting the start point and the end point of the parametric curve and the parametric curve, virtually divides a drawing area into a plurality of mesh areas of a predetermined size, calculates an area value of the graphic pattern arranged in each mesh area using the drawing data, and calculates a charged particle beam irradiation amount with proximity effect corrected using the area value. The charged particle beam lithography apparatus includes a correction unit that distributes the area value of the curved portion to a mesh area including the centroid of the curved portion.

[0012] A program according to one aspect of the present invention is a program that causes a computer to generate drawing data used in a charged particle beam lithography apparatus. For a graphic pattern included in design data, the program includes steps of dividing a curve surrounding the graphic pattern into a plurality of divided curves so that the curve is of a size equal to or less than a predetermined size, calculating a plurality of control points that parametrically represent each divided curve, calculating a feature amount of a curved portion surrounded by the parametric curve and a line segment connecting the start point and the end point of the parametric curve among the plurality of control points, and generating the drawing data including position information of the plurality of control points and the feature amount of the curved portion, and causing the computer to execute these steps.

Advantages of the Invention

[0013] According to the present invention, it is possible to perform high-speed and accurate calculation of the mesh area of a graphic including a curve.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments, as an example of a charged particle beam, a configuration using an electron beam will be described. However, the charged particle beam is not limited to an electron beam, and an ion beam or the like may be used.

[0016] FIG. 1 is a schematic diagram of a multi-charged particle beam lithography apparatus 1 (hereinafter referred to as the lithography apparatus 1) that performs lithography using drawing data according to the present embodiment. The lithography apparatus 1 includes a lithography unit 10 that irradiates a substrate 34 to be lithographed, such as a mask blank or a wafer, with an electron beam to draw a desired pattern, and a control unit 50 that controls the lithography operation by the lithography unit 10. The lithography unit 10 has an electron optical column 12 and a lithography chamber 30.

[0017] In the electron optical column 12, an electron source 14, an illumination lens 16, a shaping aperture array substrate 18, a blanking aperture array substrate 20, a reduction lens 22, a limiting aperture member 24, an objective lens 26, and a deflector 28 are arranged. An XY stage 32 is arranged in the lithography chamber 30. A substrate 34 to be lithographed is placed on the XY stage 32. Further, a mirror 36 for measuring the position of the XY stage 32 is arranged on the XY stage 32.

[0018] The control unit 50 includes a control computer 51, deflection control circuits 54, 56, and a stage position detector 58. The control computer 51, the deflection control circuits 54, 56, and the stage position detector 58 are connected to each other via a bus.

[0019] The electron beam 40 emitted from the electron source 14 illuminates the shaped aperture array substrate 18 substantially perpendicularly by the illumination lens 16. In the shaped aperture array substrate 18, openings are formed in a matrix at a predetermined arrangement pitch. The electron beam 40 illuminates a region including a plurality (all) of the openings of the shaped aperture array substrate 18. By a part of the electron beam 40 passing through each of these plurality of openings, multi-beams 40a to 40e as shown in FIG. 1 are formed.

[0020] In the blanking aperture array substrate 20, through holes are formed in accordance with the arrangement positions of the openings of the shaped aperture array substrate 18, and in each through hole, a blanker composed of a pair of two electrodes is arranged. The electron beams 40a to 40e passing through each through hole are each independently deflected by the voltage applied by the blanker and blanking-controlled. In this way, a plurality of blankers perform blanking deflection of the corresponding individual beams among the multi-beams passing through the plurality of openings of the shaped aperture array substrate 18.

[0021] The multi-beams 40a to 40e that have passed through the blanking aperture array substrate 20 are reduced by the reduction lens 22 and proceed toward the opening formed in the restriction aperture member 24. Here, the individual beam deflected by the blanker of the blanking aperture array substrate 20 is displaced from the opening of the restriction aperture member 24 and shielded by the restriction aperture member 24. On the other hand, the individual beam not deflected by the blanker of the blanking aperture array substrate 20 passes through the opening of the restriction aperture member 24.

[0022] In this way, the limiting aperture member 24 shields each beam deflected to the beam OFF state by the blanker of the blanking aperture array substrate 20. Then, the beam that has passed through the limiting aperture member 24 from when the beam is ON until it becomes OFF becomes the beam for one shot. The multi-beams 40a to 40e that have passed through the limiting aperture member 24 are focused by the objective lens 26 to form a pattern image with a desired reduction ratio. Each beam (the entire multi-beam) that has passed through the limiting aperture member 24 is deflected together in the same direction by the deflector 28 and irradiated onto the substrate 34.

[0023] When the XY stage 32 is continuously moving, the irradiation position of the beam is controlled by the deflector 28 so as to follow the movement of the XY stage 32. The movement of the XY stage 32 is performed by a stage control unit (not shown). The stage position detector 58 has a laser interferometer that irradiates a mirror 36 with a laser and receives the reflected light, detects the position of the XY stage 32, and notifies the stage control unit of the position of the XY stage 32.

[0024] The multi-beams irradiated at one time will ideally be arranged at a pitch obtained by multiplying the arrangement pitch of the plurality of openings of the shaping aperture array substrate 18 by the above-described desired reduction ratio. This drawing apparatus 1 performs a drawing operation in a raster scan method of continuously irradiating shot beams in order, and when drawing a desired pattern, the necessary beams are controlled to be beam ON by blanking control according to the pattern.

[0025] The control computer 51 includes a shot data generation unit 52 and a correction unit 53. The shot data generation unit 52 reads the drawing data D1 from the storage device 60, performs a multi-stage data conversion process, and generates device-specific shot data. The shot data defines the irradiation amount and irradiation position coordinates of each shot. For example, the shot data generation unit 52 assigns the graphic patterns defined in the drawing data to the corresponding pixels (irradiation unit areas per beam of the multi-beam). Then, the shot data generation unit 52 calculates the area density ρ1 of the graphic pattern arranged for each pixel and calculates the irradiation amount (dose amount) proportional to the area density. Specifically, the irradiation amount is calculated as the value obtained by multiplying the preset reference irradiation amount D base by the value obtained by multiplying the proximity effect correction irradiation coefficient and the area density ρ1.

[0026] The proximity effect correction irradiation coefficient is calculated by the correction unit 53. The correction unit 53 virtually divides the drawing area of the substrate 34 into a plurality of mesh areas with a predetermined size (for example, about 1 / 10 of the influence range of the proximity effect, about 100 nm), calculates the area density ρ of the graphic pattern arranged in each mesh area, and uses the area density ρ to calculate the proximity effect correction irradiation coefficient for each mesh area. The proximity effect correction irradiation coefficient can be defined by a threshold model for proximity effect correction similar to the conventional method using the backscattering coefficient η, the irradiation amount threshold D th of the threshold model, the area density ρ, and the distribution function.

[0027] The above reference irradiation amount D base is, D base =D th / (1 / 2 + η). By dividing the irradiation amount of each pixel defined in the shot data by the current density, the irradiation time of each pixel is calculated. The deflection control circuit 54 transmits a blanking control signal based on the calculated irradiation time to the blanking aperture array substrate 20.

[0028] This embodiment can calculate the area density ρ of the mesh area for obtaining the proximity effect correction irradiation coefficient quickly and accurately.

[0029] First, a method for generating drawing data D1 will be described. When the layout of a semiconductor integrated circuit is designed, design data (CAD data) D0 serving as layout data is generated and input to the input section of a conversion device 70. The conversion device 70 (drawing data generation device) performs a conversion process on the design data D0 to generate drawing data D1 that is input to the control computer 51 of the drawing device 1.

[0030] The design data D0 includes figures surrounded by curves (or figures in which curves and straight lines are mixed). The conversion device 70 calculates a plurality of control points for expressing the curves (parametric curve representation) for the curve portions, and obtains information on the positions of the control points and the curve types. The conversion device 70 generates the drawing data D1 by sequentially defining the position information of the plurality of control points so as to go around the figure from one vertex (figure arrangement origin). The conversion device 70 (drawing data generation device) has the functions of a division processing section, a control point calculation section, a feature amount calculation section, and a generation section, which will be described later. At least a part of the conversion device 70 may be configured by hardware or software.

[0031] The division processing section of the conversion device 70 divides the curve surrounding the figure so that it becomes equal to or smaller than the size (the length of one side in the vertical or horizontal direction of the mesh area) for dividing the drawing area into mesh areas when performing the above-described proximity effect correction operation. The control point calculation section of the conversion device 70 represents (approximates) the divided curve (divided curve) by a parametric curve defined by four control points. As the type of parametric curve, for example, one in which the end points of the control points such as a Bézier curve are on the divided curve can be used.

[0032] For example, as shown in FIG. 2, the divided curve is represented by a cubic Bézier curve. In the example shown in FIG. 2, the curve surrounding the figure (the curve that becomes the contour line of the figure) is represented by 11 Bézier curves K0 to K10.

[0033] The Bézier curve K0 is represented by four control points PP0, EP(0,0), EP(0,1), and EP(0,2). Among the four control points, two control points (endpoints), namely the starting point PP0 and the ending point EP(0,2), are located on the curve. The point PP0 is the starting point of the Bézier curve K0 and the ending point of the Bézier curve K10.

[0034] The Bézier curve K1 is represented by four control points EP(0,2), EP(1,0), EP(1,1), and EP(1,2). Among the four control points, two control points (endpoints), namely the starting point EP(0,2) and the ending point EP(1,2), are located on the curve. The control point EP(0,2) is the starting point of the Bézier curve K1 and the ending point of the Bézier curve K0.

[0035] The Bézier curve K2 is represented by four control points EP(1,2), EP(2,0), EP(2,1), and EP(2,2). Among the four control points, two control points (endpoints), namely the starting point EP(1,2) and the ending point EP(2,2), are located on the curve. The control point EP(1,2) is the starting point of the Bézier curve K2 and the ending point of the Bézier curve K1.

[0036] The Bézier curves K3 to K10 are represented in the same manner as above.

[0037] The feature quantity calculation unit of the conversion device 70 obtains the area of the curve part as the feature quantity of each Bézier curve. The area of the curve part is the area of the region surrounded by the line segment connecting the endpoints (starting point and ending point) of the four control points and the Bézier curve. For example, as shown in FIG. 3, the area CA(1) of the curve part of the Bézier curve K1 is the area of the hatched part in the figure surrounded by the line segment B L connecting the starting point EP(0,2) and the ending point EP(1,2) and the Bézier curve K1. This area can be obtained by the line integral according to the equation of the Bézier curve and Green's theorem.

[0038] Note that the length of the line segment B L connecting the starting point EP(0,2) and the ending point EP(1,2), the length of the perpendicular line B L from the control point EP(1,0) to the line segment B H1 and the length of the perpendicular line B LPerpendicular line B to H2 It is preferable that the curve surrounding the figure is divided so that the lengths of both are equal to or less than the mesh size when performing the proximity effect correction calculation.

[0039] In the example of FIG. 2, the areas CA(0) to CA(10) of the respective curve portions of the Bézier curves K0 to K10 are calculated.

[0040] The generation unit of the conversion device 70 generates drawing data D1 including the position information of the control points of all the Bézier curves based on the origin PP0 and the area information of the curve portions.

[0041] FIG. 4 shows an example of the data structure of the drawing data D1. The drawing data D1 includes a header PH, area information data, and vertex data. The header PH includes vertex number information, curve information, and the presence or absence of area information. The vertex number information represents the number of control points, which is 33 in the example of FIG. 2. The curve information represents the type and degree of the parametric curve, which is a cubic Bézier curve in the example of FIG. 2. The presence or absence of area information indicates whether the drawing data D1 includes area information data.

[0042] The area information data defines the areas of the curve portions for each Bézier curve in order. In the example of FIG. 2, the areas CA(0) to CA(10) of the respective curve portions of the Bézier curves K0 to K10 are defined in order.

[0043] The vertex data defines the position information of the control points of the Bézier curve in order from the graphic arrangement origin. In the example of FIG. 2, the position information of EP(0,0), EP(0,1), EP(0,2), EP(1,0), EP(1,1), EP(1,2),... is defined in order clockwise from the origin PP0.

[0044] The data structure of the drawing data D1 is not limited to that shown in FIG. 4. For example, as shown in FIG. 5, the position information of the origin PP0 may be described after the header portion PH, and then, for each Bézier curve, the area information and the information of (three except the start point) control points may be described. The start point of each Bézier curve is the end point of the previous Bézier curve.

[0045] Next, the proximity effect correction operation by the correction unit 53 using the drawing data D1 of such a data structure will be described.

[0046] The correction unit 53 virtually divides the drawing area of the substrate 34 into a plurality of mesh areas with a predetermined size (for example, about 100 nm), and calculates the area density ρ of the graphic pattern arranged in each mesh area. When the graphic pattern has a shape surrounded by a curve as shown in FIG. 2, for the area other than the curved portion, that is, the polygon area surrounded by the line segments connecting the start points and end points of the Bézier curves K0 to K10, the area density of each mesh area can be easily calculated by a conventionally known method. For example, the polygon is divided into triangles or trapezoids, and the area density in each mesh area is calculated.

[0047] As shown in FIG. 6, when the curved portion CA of the Bézier curve straddles two adjacent mesh areas M1 and M2, conventionally, the curved portion CA is divided at the mesh boundary, and the centroid G1 and area value of the curved portion CA1 included in the mesh area M1, and the centroid G2 and area value of the curved portion CA2 included in the mesh area M2 are calculated, and the area values are distributed to a plurality of vertices of the mesh area so that the centroid position in each mesh area does not change. For example, the area value of the curved portion CA1 is distributed to the four vertices of the mesh area M1, and the area value of the curved portion CA2 is distributed to the four vertices of the mesh area M2. However, calculating the area and centroid of each of the curved portions CA1 and CA2 divided at the mesh boundary requires a large amount of calculation, and there is a problem that the drawing processing time becomes long.

[0048] Therefore, in this embodiment, as shown in FIG. 7, when the curved portion CA straddles two adjacent mesh regions M1 and M2, instead of dividing the curved portion CA at the mesh boundary, the centroid G of the curved portion CA is obtained, and the area values are distributed to a plurality of vertices (four vertices) of the mesh region (mesh region M2 in the example of FIG. 7) that contains the centroid G. The area values are distributed so that the centroid position of the combined area values at the four vertices coincides with the centroid G. Since the area value of the curved portion CA is defined in the drawing data D1, it can be obtained at high speed. Since the curved portion CA is not divided at the mesh boundary, the amount of calculation can be reduced compared to the conventional method shown in FIG. 6.

[0049] As shown in FIG. 8, instead of the centroid G of the curved portion CA, the centroid G' of a triangle with the start point (t = 0), end point (t = 1) of the Bézier curve, and the intermediate point Pm (t = 0.5) of the parameters as vertices may be calculated, and the area values may be distributed to a plurality of vertices of the mesh region M2 that contains the centroid G'. This centroid G' can be calculated by the following formula using the coordinates P0 of the start point of the Bézier curve, the coordinates P3 of the end point, and the coordinates P1 and P2 of the other two control points.

[0050] G' = (3 × P0 + P1 + P2 + 3 × P3) / 8

[0051] When the Bézier curve is equal to or smaller than the size (100 nm) of the mesh region, the displacement amount between the centroid G' of the triangle and the centroid G of the curved portion CA is about 10 nm at most, and the correction residual becomes extremely small. Therefore, the centroid G' can be treated as the approximate centroid of the curved portion CA. By obtaining the approximate centroid G', the amount of calculation for centroid calculation can be reduced.

[0052] The correction unit 53 calculates the centroid G (or G') and distributes the area values to a plurality of vertices of the mesh region that contains the centroid G (or G') for all the curved portions of the Bézier curves. When a plurality of centroids G (or G') of the curved portions are included in one mesh region, the distributed area values are cumulatively added to the vertices of that mesh region.

[0053] The correction unit 53 calculates the area value (area density ρ) for each mesh region using the area values of the four vertices of each mesh region, and obtains the proximity effect correction irradiation coefficient.

[0054] Thus, according to this embodiment, when the curved portion of the Bézier curve straddles two mesh regions, since the area value is assigned to the mesh region containing the centroid, the mesh area calculation can be performed at high speed. Also, by approximating the centroid of the curved portion of the Bézier curve to the centroid of the triangle formed by the start point, end point, and intermediate point of the Bézier curve, the centroid position can be obtained at high speed while suppressing a decrease in accuracy. Since the area of the curved portion of the Bézier curve is defined in the drawing data D1, it can be acquired promptly.

[0055] In the above embodiment, the value of the area itself is defined as the area information of the curved portion of the Bézier curve in the drawing data D1. However, instead of the area value, a value obtained by dividing the area by the length of the line segment connecting the start point and the end point may be defined. Thereby, the data amount of the area information can be reduced. The control computer 51 calculates the length of the line segment connecting the start point and the end point from the coordinates of the start point and the end point of the Bézier curve defined in the drawing data D1, and multiplies this line segment length by the value defined in the area information to obtain the area value of the curved portion.

[0056] Also, the square root value of the area value may be defined as the area information of the curved portion of the Bézier curve in the drawing data D1. Thereby, the data amount of the area information can be reduced. The control computer 51 squares the value defined in the area information of the drawing data D1 to obtain the area value of the curved portion.

[0057] In the above embodiment, an example in which the area of the curved portion of the Bézier curve is distributed to the mesh region containing the centroid G (or approximate centroid G´) of the curved portion of the Bézier curve has been described. However, for a plurality of mesh regions containing a quadrilateral (a part of the quadrilateral) having the four control points of the Bézier curve as vertices, the area of the quadrilateral applied to each mesh region is obtained, and the area of the curved portion may be distributed to each mesh region according to the ratio of the obtained areas.

[0058] Alternatively, a bounding box that encloses a quadrilateral with the four control points of the Bézier curve as vertices may be obtained, and for a plurality of mesh regions that include the bounding box (a part of the bounding box), the area of the bounding box applied to each mesh region may be obtained, and the area of the curve portion may be distributed to each mesh region according to the ratio of the obtained areas.

[0059] As the area of the curve portion of the Bézier curve defined in the drawing data D1, the area of a triangle composed of the start point, end point, and intermediate point of the Bézier curve may be used. Also, area information may not be defined in the drawing data D1, and the control computer 51 may calculate the area of a triangle composed of the start point, end point, and intermediate point of the Bézier curve from the vertex data.

[0060] In the above embodiment, an example of generating the drawing data D1 including the area information of the curve portion has been described. However, the drawing data D1 may include information on at least any one of other feature amounts such as the centroid of the curve portion, edge length (length of the Bézier curve), curvature, normal vector, and arbitrary attribute values instead of or in addition to the area information.

[0061] In the above embodiment, an example of dividing a curve that encloses a figure so as to be less than or equal to the mesh size when performing the proximity effect correction operation to generate a divided curve has been described. However, the present invention is not limited to the proximity effect correction, and a divided curve may be generated by dividing so as to be less than or equal to the size of the correction unit (for example, mesh size) in other correction operations such as dose correction and figure correction.

[0062] In the above embodiment, an example of dividing a curve that encloses a figure into approximately the mesh size and approximating it with a parametric curve to generate drawing data has been described. However, drawing data may be generated without restricting the size of the parametric curve. In this case, the correction unit 53, from the position information of the control points of the Bézier curve, the length of the line segment B as shown in FIG. 3 L and the length of the perpendicular line B H1 and the length of the perpendicular line B H2Determine the length, and if all of these values are less than or equal to the mesh size, calculate the approximate centroid G´, and if at least one of them is greater than the mesh size, analytically calculate the centroid G.

[0063] In the above embodiment, a multi-beam irradiation apparatus that irradiates a large number of beams at once using multi-beams has been described, but the same method can also be applied to a single-beam irradiation apparatus that irradiates a single beam onto the substrate to be irradiated.

[0064] At least a part of the control computer 51 may be configured by hardware or by software. When configured by software, a program that realizes at least a part of the functions of the control computer 51 may be stored in a recording medium such as a flexible disk or a CD-ROM, and read and executed by a computer. The recording medium is not limited to removable ones such as magnetic disks and optical disks, and may be a fixed-type recording medium such as a hard disk device or a memory.

[0065] Also, a program that realizes at least a part of the functions of the control computer 51 may be distributed via a communication line (including wireless communication) such as the Internet. Furthermore, the program may be distributed in an encrypted, modulated, or compressed state via a wired or wireless line such as the Internet, or stored in a recording medium and distributed.

[0066] Note that the present invention is not limited to the above-described embodiment as it is, and at the implementation stage, the components can be modified and embodied without departing from the gist thereof. Also, various inventions can be formed by appropriately combining a plurality of components disclosed in the above embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components from different embodiments may be appropriately combined.

Explanation of Reference Numerals

[0067] 1 Drawing apparatus 10 Drawing unit 50 Control unit 51 Control computer 52 Shot data generation unit 53 Correction unit

Claims

1. A method for generating drawing data used in a charged particle beam lithography apparatus, comprising: For a graphic pattern included in design data, dividing a curve surrounding the graphic pattern into a size equal to or less than a predetermined size to generate a plurality of divided curves, and calculating a plurality of control points for parametric curve representation of each divided curve; Calculating a feature amount of a curved portion surrounded by the parametric curve and a line segment connecting the start point and the end point of the parametric curve among the plurality of control points; Generating the drawing data including position information of the plurality of control points and the feature amount of the curved portion.

2. The charged particle beam lithography apparatus virtually divides a drawing area into a plurality of mesh areas in a correction operation, The method for generating drawing data according to claim 1, wherein the predetermined size is determined based on a size in a horizontal direction or a vertical direction of the mesh area.

3. The method for generating drawing data according to claim 1, wherein the feature amount includes an area, a centroid, an edge length, a curvature, a normal vector, or an arbitrary attribute value of the curved portion.

4. The method for generating drawing data according to claim 1, wherein the feature amount is a value obtained by dividing an area of the curved portion by a length of a line segment connecting the start point and the end point of the parametric curve.

5. The method for generating drawing data according to claim 1, wherein the start point and the end point of the parametric curve are located on the divided curve.

6. A drawing data generation apparatus for generating drawing data used in a charged particle beam lithography apparatus, comprising: An input unit for inputting design data including a graphic pattern; A division processing unit for dividing a curve surrounding the graphic pattern included in the design data input to the input unit into a size equal to or less than a predetermined size to generate a plurality of divided curves; A control point calculation unit for calculating a plurality of control points for parametric curve representation of each divided curve; A feature amount calculation unit for calculating a feature amount of a curved portion surrounded by the parametric curve and a line segment connecting the start point and the end point of the parametric curve among the plurality of control points; A generation unit for generating the drawing data including position information of the plurality of control points and the feature amount of the curved portion; A drawing data generation apparatus comprising the above components.

7. A program for causing a computer to generate drawing data used in a charged particle beam lithography apparatus, For the graphic pattern included in the design data, a step of dividing the curve surrounding the graphic pattern into a size equal to or smaller than a predetermined size to generate a plurality of divided curves, and calculating a plurality of control points for parametric curve representation of each divided curve; A step of calculating a feature amount of a curve portion surrounded by the parametric curve and a line segment connecting the start point and the end point of the parametric curve among the plurality of control points; A step of generating the drawing data including the position information of the plurality of control points and the feature amount of the curve portion; A program for causing a computer to execute.

8. Regarding the graphic pattern to be drawn, reading from a storage device drawing data including the position information of each control point of a plurality of parametric curves surrounding the graphic pattern, and area information of a curve portion surrounded by a line segment connecting the start point and the end point of the parametric curve and the parametric curve; Virtually dividing a drawing area into a plurality of mesh areas of a predetermined size, calculating an area value of the graphic pattern arranged in each mesh area using the drawing data; A charged particle beam drawing method for calculating a charged particle beam irradiation amount with proximity effect corrected using the area value, A charged particle beam drawing method of distributing the area value of the curve portion to a mesh area including the centroid of the curve portion.

9. The charged particle beam drawing method according to claim 8, wherein as the centroid of the curve portion, the centroid of a triangle having the start point, the end point of the parametric curve, and an intermediate point of the parameter as vertices is calculated.

10. The charged particle beam drawing method according to claim 8, wherein a charged particle beam is irradiated onto a substrate to be drawn with the charged particle beam irradiation amount to draw a pattern.

11. Regarding the graphic pattern to be drawn, reading from a storage device drawing data including the position information of each control point of a plurality of parametric curves surrounding the graphic pattern, and area information of a curve portion surrounded by a line segment connecting the start point and the end point of the parametric curve and the parametric curve; Virtually dividing a drawing area into a plurality of mesh areas of a predetermined size, calculating an area value of the graphic pattern arranged in each mesh area using the drawing data; A charged particle beam drawing apparatus for calculating a charged particle beam irradiation amount with proximity effect corrected using the area value, A charged particle beam lithography apparatus comprising a correction unit that distributes the area value of the curved portion to a mesh region including the centroid of the curved portion.

12. For a graphic pattern to be drawn, drawing data including position information of control points of each of a plurality of parametric curves surrounding the graphic pattern and area information of a curved portion surrounded by a line segment connecting the start point and the end point of the parametric curve and the parametric curve is read from a storage device. The drawing area is virtually divided into a plurality of mesh regions of a predetermined size, and the area value of the graphic pattern arranged in each mesh region is calculated using the drawing data. A charged particle beam lithography method for calculating a charged particle beam irradiation amount with proximity effect corrected using the area value, When the curved portion straddles a plurality of mesh regions, a quadrilateral having control points of the parametric curve corresponding to the curved portion as vertices, or a bounding box surrounding the quadrilateral is obtained, and for the plurality of mesh regions covered by the quadrilateral or the bounding box, the area value of the curved portion is distributed according to the ratio of the area of the quadrilateral or the bounding box covering each mesh region. A charged particle beam lithography method.

13. For a graphic pattern to be drawn, drawing data including position information of control points of each of a plurality of parametric curves surrounding the graphic pattern and area information of a curved portion surrounded by a line segment connecting the start point and the end point of the parametric curve and the parametric curve is read from a storage device. The drawing area is virtually divided into a plurality of mesh regions of a predetermined size, and the area value of the graphic pattern arranged in each mesh region is calculated using the drawing data. A charged particle beam lithography apparatus for calculating a charged particle beam irradiation amount with proximity effect corrected using the area value, A quadrilateral having control points of the parametric curve corresponding to the curved portion as vertices, or a bounding box surrounding the quadrilateral is obtained, and for the plurality of mesh regions covered by the quadrilateral or the bounding box, the area value of the curved portion is distributed according to the ratio of the area of the quadrilateral or the bounding box covering each mesh region. A charged particle beam lithography apparatus comprising a correction unit.

Images