阅读说明：本技术 多带电粒子束评价方法以及多带电粒子束描绘装置 (Method for evaluating multiple charged particle beams and multiple charged particle beam drawing device ) 是由 西村理惠子 于 2020-09-10 设计创作，主要内容包括：本发明涉及多带电粒子束评价方法以及多带电粒子束描绘装置。基于本发明的一个方案的多带电粒子束评价方法具备：使用多带电粒子束在基板上以预定的间距描绘使线宽的设计值以预定的变化量变化的多个评价图案的工序；测定所描绘的多个评价图案的线宽的工序；以及提取出多个评价图案的线宽测定结果与设计值之间的差值的分布在特定周期中的变动的工序。上述预定的变化量为数据分辨率以上,且比成为多带电粒子束的每一束的照射单位区域的像素的尺寸小。(The present invention relates to a method for evaluating a plurality of charged particle beams and a plurality of charged particle beam drawing apparatus. The method for evaluating a plurality of charged particle beams according to one aspect of the present invention includes: a step of drawing a plurality of evaluation patterns, which change a design value of a line width by a predetermined amount of change, on a substrate at a predetermined pitch using a plurality of charged particle beams; measuring line widths of the drawn plurality of evaluation patterns; and extracting a variation in a distribution of a difference between the line width measurement result and the design value of the plurality of evaluation patterns in a specific period. The predetermined variation is equal to or greater than the data resolution and is smaller than the size of a pixel in an irradiation unit area of each of the multiple charged particle beams.)

1. A method for evaluating multiple charged particle beams, comprising:

a step of drawing a plurality of evaluation patterns, which change a design value of a line width by a predetermined amount of change, on a substrate at a predetermined pitch using a plurality of charged particle beams;

measuring line widths of the plurality of drawn evaluation patterns; and

extracting a variation in a distribution of a difference between a line width measurement result and a design value of the plurality of evaluation patterns in a specific period,

the predetermined change amount is equal to or greater than a data resolution and is smaller than a size of a pixel that becomes an irradiation unit area of each of the plurality of charged particle beams.

2. The multi charged particle beam evaluation method of claim 1, wherein,

the variation in the specific period is extracted by analyzing the spatial frequency.

3. The multi charged particle beam evaluation method of claim 1, wherein,

in the above description, the correction function is turned off and the description is performed.

4. The multi charged particle beam evaluation method of claim 2, wherein,

pattern data of the evaluation pattern is arranged at start coordinates of a grid dividing the evaluation pattern into the pixels, and drawing data of the evaluation pattern is created so that an arrangement pitch of the pattern data is an integral multiple of the grid.

5. The multi charged particle beam evaluation method of claim 1, wherein,

the plurality of evaluation patterns are simultaneously drawn using different ones of the plurality of charged particle beams.

6. A method for evaluating multiple charged particle beams, comprising:

a step of drawing a plurality of evaluation patterns on the substrate by using a plurality of charged particle beams so that the pitch in design changes by a predetermined amount of change;

measuring pitches of the plurality of evaluation patterns; and

extracting a variation in a distribution of a difference between a measurement result of the pitch of the plurality of evaluation patterns and a design value in a specific period,

the predetermined change amount is smaller than a size of a pixel that becomes an irradiation unit area of each of the plurality of charged particle beams.

7. The multi charged particle beam evaluation method of claim 6, wherein,

the variation in the specific period is extracted by analyzing the spatial frequency.

8. The multi charged particle beam evaluation method of claim 6, wherein,

in the above description, the correction function is turned off and the description is performed.

9. The multi charged particle beam evaluation method of claim 8, wherein,

pattern data of the evaluation pattern is arranged at start coordinates of a grid dividing the evaluation pattern into the pixels, and drawing data of the evaluation pattern is created so that an arrangement pitch of the pattern data is an integral multiple of the grid.

10. The multi charged particle beam evaluation method of claim 6, wherein,

the plurality of evaluation patterns are simultaneously drawn using different ones of the plurality of charged particle beams.

11. A method for evaluating multiple charged particle beams, comprising:

drawing a plurality of evaluation patterns having a designed line width on a substrate at a predetermined pitch using a plurality of charged particle beams;

measuring line widths of the plurality of drawn evaluation patterns; and

extracting a variation in a distribution of a difference between a line width measurement result and a design value of the plurality of evaluation patterns in a specific period,

each evaluation pattern has a plurality of rectangular portions which are offset in the width direction and connected,

the plurality of rectangular portions have a shift width equal to or larger than a data resolution and smaller than a size of a pixel constituting an irradiation unit area of each of the plurality of charged particle beams,

the line width of each rectangular portion was measured.

12. The multi charged particle beam evaluation method of claim 11, wherein,

the variation in the specific period is extracted by analyzing the spatial frequency.

13. The multi charged particle beam evaluation method of claim 11, wherein,

in the above description, the correction function is turned off and the description is performed.

14. The multi charged particle beam evaluation method of claim 13, wherein,

pattern data of the evaluation pattern is arranged at start coordinates of a grid dividing the evaluation pattern into the pixels, and drawing data of the evaluation pattern is created so that an arrangement pitch of the pattern data is an integral multiple of the grid.

15. The multi charged particle beam evaluation method of claim 11, wherein,

the plurality of evaluation patterns are simultaneously drawn using different ones of the plurality of charged particle beams.

16. A multi-charged particle beam drawing device is provided with:

a drawing unit that draws a pattern on a substrate using a plurality of charged particle beams; and

and a controller that controls the drawing unit to draw, on the substrate, a plurality of linear evaluation patterns having a line width variation amount equal to or greater than a data resolution and smaller than a pixel size of an irradiation unit region of each of the plurality of charged particle beams at a predetermined pitch.

17. The multi-charged particle beam delineation apparatus of claim 16, wherein,

the correction function is turned off to draw the evaluation pattern.

Technical Field

The present invention relates to a method for evaluating a plurality of charged particle beams and a plurality of charged particle beam drawing apparatus.

Background

With the high integration of LSIs, the circuit line width required for semiconductor devices has been miniaturized year by year. In order to form a desired circuit pattern in a semiconductor device, the following method is employed: a high-precision original pattern (a mask, or a reticle used in a stepper or a scanner in particular) formed on quartz is transferred onto a wafer in a reduced size by using a reduced projection exposure apparatus. The high-precision original pattern is drawn by an electron beam drawing apparatus using a so-called electron beam lithography technique.

In the drawing apparatus using a plurality of particle beams, since a larger number of particle beams can be irradiated at one time than in the case of drawing with 1 electron beam, the throughput can be greatly improved. In a multi-particle beam writing apparatus using a blanked aperture array, which is one embodiment of the multi-particle beam writing apparatus, for example, electron beams emitted from 1 electron gun are passed through a shaping aperture array having a plurality of openings to form a plurality of particle beams (a plurality of electron beams). The multiple particle beams pass within blanking apertures of each respective blanking aperture array. The blanking aperture array has electrode pairs for deflecting the particle beams independently, and openings for passing the particle beams are formed between the electrode pairs. Blanking deflection of the passing electron beam is performed by fixing one electrode of the electrode pair (blanker) at a ground potential and switching the other electrode between the ground potential and a potential other than the ground potential. The electron beam deflected by the blanker is shielded, and the undeflected electron beam is irradiated onto the substrate.

The multi-particle beam drawing device divides a drawing region of a substrate into a plurality of pixels in a grid pattern, and draws a desired pattern by a combination of pixel patterns (bitmaps) formed by irradiating each pixel with a particle beam of a required irradiation dose. When the pixel size is the particle beam size, 1 pixel is irradiated with 1 particle beam. Pixels are assigned to a pattern defined by drawing data, and the irradiation amount of each pixel is calculated based on the area density of the pattern arranged for each pixel. Therefore, when the irradiation amount of the particle beam with respect to the pixel having the irradiation area density of 100% is set to 100%, there is a particle beam having an irradiation amount less than 100%.

In multi-particle beam lithography, a particle beam whose irradiation position is shifted is generated due to the characteristics of an optical system and the like. Since the entire multi-particle beam is deflected at once, the positions of the particle beams cannot be corrected independently. Therefore, the irradiation amount modulation processing for distributing the irradiation amount to the surrounding particle beams according to the amount of positional displacement of the particle beams is performed so that the particle beam positional displacement is not affected in the dose distribution given to the resist even when the exposure is performed by the particle beams after the positional displacement.

In this way, there is a large amount of particle beams (gray-scale beams) with an irradiation amount of less than 100% due to the pattern area density of the corresponding pixel or the irradiation amount modulation processing. When the irradiation amount is not appropriately adjusted, the dimensional accuracy or positional accuracy of the drawn pattern may be affected. Further, the influence of blurring of each particle beam may appear. Therefore, a method capable of quantitatively and easily evaluating controllability and resolution of a gray scale beam is desired.

Disclosure of Invention

The invention provides a multi-charged particle beam evaluation method and a multi-charged particle beam drawing device capable of easily evaluating controllability and resolving power of a gray scale beam.

A method for evaluating a multi-charged particle beam according to an aspect of the present invention includes: a step of drawing a plurality of evaluation patterns, which change a design value of a line width by a predetermined amount of change, on a substrate at a predetermined pitch using a plurality of charged particle beams; measuring line widths of the plurality of drawn evaluation patterns; and extracting a variation in a distribution of a difference between the line width measurement result and a design value of the plurality of evaluation patterns in a specific period. The predetermined change amount is equal to or greater than a data resolution and is smaller than a size of a pixel that becomes an irradiation unit area of each of the plurality of charged particle beams.

Drawings

Fig. 1 is a schematic diagram of a multi-charged particle beam drawing apparatus according to an embodiment of the present invention.

Fig. 2 is a diagram illustrating an example of the scanning operation.

Fig. 3 (a) to (d) are diagrams illustrating an example of the drawing operation.

Fig. 4 (a) is a diagram showing an example of the grid, and fig. 4 (b) and (c) are diagrams showing an example of the grid being deviated from the grid.

Fig. 5 (a) is a diagram showing an example of the grid, and fig. 5 (b) is a diagram showing an example of the grid being deviated.

Fig. 6 is a flowchart for explaining the multi-particle beam evaluation method according to the embodiment.

Fig. 7 is a diagram showing an example of the evaluation pattern.

Fig. 8 is a graph showing an example of the distribution of the difference between the dimension measurement result of the evaluation pattern and the design value.

Fig. 9 is a diagram showing an example of the evaluation pattern.

Fig. 10 is a diagram showing an example of the evaluation pattern.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a structure in which an electron beam is used as an example of a charged particle beam will be described. However, the charged particle beam is not limited to the electron beam, and may be an ion beam or the like.

Fig. 1 is a schematic configuration diagram of a drawing apparatus according to the present embodiment. The drawing device includes a control unit 1 and a drawing unit 2. The drawing device is an example of a multi-charged particle beam drawing device. The drawing unit 2 includes an electron barrel 20 and a drawing chamber 30. In the electron tube 20, an electron gun 21, an illumination lens 22, a molding aperture array substrate 23, a blanking aperture array substrate 24, a reduction lens 25, a limiting aperture member 26, an objective lens 27, and a deflector 28 are arranged. The reduction lens 25 and the objective lens 27 are each constituted by an electromagnetic lens, and the reduction lens 25 and the objective lens 27 constitute a reduction optical system.

An XY stage 32 is disposed in the drawing chamber 30. A substrate 40 to be drawn is placed on the XY table 32. The substrate 40 is an exposure mask in manufacturing a semiconductor device, a semiconductor substrate (silicon wafer) in manufacturing a semiconductor device, a mask substrate coated with a resist but not yet patterned, or the like.

In the molded aperture array substrate 23, m rows and n columns (m, n ≧ 2) of openings are formed in a matrix at a predetermined arrangement pitch. Each opening is formed by a rectangle or a circle of the same size and shape.

The electron beam B emitted from the electron gun 21 illuminates the entire plurality of openings of the shaped aperture array substrate 23 substantially perpendicularly by the illumination lens 22. The electron beam B passes through a plurality of openings of the shaped aperture array substrate 23, thereby forming m rows and n columns of electron beams (multi-particle beams) MB.

In the blanking aperture array substrate 24, through holes are formed corresponding to the positions where the openings of the molding aperture array substrate 23 are arranged. A pair of 2 electrode groups (blanker: blanking deflector) is disposed in each passage hole. One of the 2 electrodes for each particle beam is connected to an amplifier for applying a voltage, and the other is grounded. The electron beams passing through the respective pass holes are deflected independently of each other by means of voltages applied to the pairs of 2 electrodes. Blanking control is performed by deflection of the electron beam.

The multi-particle beam MB having passed through the blanking aperture array substrate 24 is reduced by the reduction lens 25, and advances toward the central opening formed in the limiting aperture member 26. The electron beam deflected by the blanker of the blanking aperture array substrate 24 is shifted in position with respect to the central opening of the limiting aperture member 26, and is shielded by the limiting aperture member 26. On the other hand, the electron beam not deflected by the blanker passes through the opening in the center of the limiting aperture part 26.

In this way, the limiting aperture member 26 shields each particle beam deflected by the blanker so as to be in a state where the particle beam is cut off. Further, a particle beam of an amount corresponding to 1 emission is formed by the particle beam passing through the limiting aperture member 26, which is formed during a period from the passage of the particle beam to the cutoff of the particle beam.

The multi-particle beam MB having passed through the limiting aperture member 26 is focused by the objective lens 27 to form a pattern image with a desired reduction ratio, and is collectively deflected by the deflector 28 to be irradiated onto the substrate 40. For example, when the XY table 32 is continuously moved, the deflector 28 controls the irradiation position of the particle beam to follow the movement of the XY table 32.

The multi-particle beams MB to be irradiated at one time are ideally arranged at a pitch obtained by multiplying the arrangement pitch of the plurality of openings of the molding aperture array substrate 23 by the desired reduction ratio. The drawing device performs a drawing operation in a raster scanning system in which emitted particle beams are successively irradiated, and when a desired pattern is drawn, a necessary particle beam is controlled to pass through the particle beam by blanking control in accordance with the pattern.

As shown in fig. 2, the drawing region 50 of the substrate 40 is virtually divided into a plurality of strip-shaped regions 52 each having a predetermined width in the y direction, for example. For example, the XY table 32 is moved, and the irradiation region that can be irradiated by the irradiation of the primary multi-particle beam MB is adjusted so as to be positioned at the left end of the 1 st band-shaped region 52, and the drawing is started. By moving the XY table 32 in the-x direction, the drawing can be relatively advanced in the x direction.

After the drawing of the 1 st band-shaped region 52 is completed, the stage position is moved in the-y direction, the irradiation region is adjusted so as to be positioned at the right end of the 2 nd band-shaped region 52, and the drawing is started. Further, the XY table 32 is moved, for example, in the x direction, thereby drawing in the-x direction.

By alternately changing the orientation and performing drawing so as to draw in the x direction in the 3 rd band-shaped region 52 and draw in the-x direction in the 4 th band-shaped region 52, the drawing time can be shortened. However, the drawing is not limited to the case where the direction is alternately changed, and the drawing may be performed in the same manner when drawing each band-shaped region 52.

Fig. 3 (a) to (d) are diagrams illustrating an example of the drawing operation in the band-shaped region 52. Fig. 3 (a) to (d) show examples in which a multi-particle beam of 4 × 4 is used to draw in the band-shaped region 52 in the x and y directions, for example.

The band-shaped region 52 is divided into a plurality of pixel regions PX (hereinafter referred to as pixels PX) in a grid pattern, for example. In this example, 1 irradiation region of the entire multi-particle beam is exposed (drawn) by 16 shots while shifting the irradiation position by 1 pixel PX at a time in the x-direction or the y-direction. The 1 pixel PX is an irradiation unit area of each 1 particle beam. That is, the size of the pixel PX is the particle beam size.

Fig. 3 (a) shows the pixel PX irradiated by 1 time emission. Next, as shown in fig. 3 (b), the 2 nd, 3 rd, and 4 th emission are performed in sequence while shifting the position by 1 pixel at a time in the y direction, and next, as shown in fig. 3 (c), the 5 th emission is performed while shifting the position by 1 pixel in the x direction. Next, while shifting the position in the y direction by 1 pixel at a time, the 6 th, 7 th, and 8 th emissions are performed in order. The same operation is repeated, and the remaining 9 th to 16 th shots are sequentially performed as shown in fig. 3 (d). With 16 shots, a range divided by the beam pitch can be rendered with 1 beam.

When performing the drawing process, the control unit 1 reads drawing data from a storage unit (not shown), and calculates the pattern area density ρ of all the pixels PX in each band-shaped region 52 using the pattern defined by the drawing data. The control unit 1 multiplies the pattern area density ρ by the reference dose D₀Calculating the irradiation amount ρ D of the particle beam irradiated to each pixel PX₀。

For example, when a linear pattern is assigned to each pixel, the pattern area density ρ is 100% and less than 100% for the pixels at the ends in the short side direction of the pattern. When the pattern area density ρ of the pixels at the end portions is 100%, the edge of the pattern (hatched portion in the figure) coincides with the boundary of the pixel PX as shown in fig. 4 (a).

When the pattern area density ρ is less than 100%, the boundary between the pattern edge and the pixel PX is not uniform as shown in fig. 4 (b) and 4 (c). The pixels PX at the end portions are irradiated with a gray beam whose irradiation amount corresponds to the pattern area density ρ. By adjusting the irradiation amount to the pixels PX at the end portions, the line width (W, W1, W2) of the line pattern can be controlled.

While fig. 4 (a) to 4 (c) show examples of adjusting the irradiation amount to the pixel PX at the right end portion in the figure, the irradiation amount to the pixel PX at the left end portion can also be adjusted as shown in fig. 5 (a) and 5 (b).

In the following description, a state in which the edge of the pattern coincides with the boundary of the pixel PX as shown in fig. 4 (a) and 5 (a) is referred to as "on the grid", and a state in which the edge of the pattern does not coincide with the boundary of the pixel PX as shown in fig. 4 (b), 4 (c) and 5 (b) when the gray-scale beam is irradiated is referred to as "off the grid".

In this way, in the multi-particle beam drawing, by adjusting the irradiation amount (the gradation value indicating the irradiation time) of each pixel, the size and the arrangement position of the pattern can be controlled to a size smaller than the particle beam size in the x direction or the y direction and larger than the data resolution. Therefore, the controllability of the gray beam or the resolving power needs to be evaluated.

As shown in fig. 6, the method for evaluating the particle beam irradiation amount controllability of a multi-particle beam according to the present embodiment includes: an evaluation pattern drawing step (step S1), a step of measuring the dimensions of the drawn evaluation pattern (step S2), and a step of analyzing the irradiation dose control performance from the measurement results of the dimensions (step S3).

In the evaluation pattern drawing step, the XY stage 32 is stopped, and a plurality of line patterns, as shown in fig. 7, in which line widths are gradually changed in steps of a data resolution or more and a particle beam size (pixel size) or less, are drawn on the substrate 40 as an evaluation pattern at a predetermined pitch N in parallel with each other. For example, the pitch N is a size that can deflect 1 particle beam by the deflector 28. The pitches of one end side (the left end side in the figure) in the line width direction of the linear pattern are the same value N. 1 line pattern is depicted by 1 particle beam. The plurality of line patterns are simultaneously drawn by different beams, respectively.

The different beams are particle beams passing through different openings of the shaped aperture array substrate 23. In other words, the different beams are particle beams passing through different passing holes of blanking aperture array substrate 24. The line width direction (width direction) of the linear pattern is the short side direction of the linear pattern. The line width direction of the linear pattern is orthogonal to the longitudinal direction (extending direction) of the linear pattern.

In the example shown in fig. 7, the particle beam size is set to R, and the line width is changed by R/10 each time. That is, the evaluation pattern was drawn so that the pattern P0 with the line width N/2, the pattern P1 with the line width N/2+ R/10, the pattern P2 with the line width N/2+2R/10, the pattern P3 with the line width N/2+3R/10, and the pattern P9 with the line width N/2+9R/10 were repeatedly arranged. For example, when the particle beam size R is 10nm, the line widths of the patterns P0 to P9 are sequentially different by 1 nm.

By adjusting the irradiation amount of the pixels at the end portion (right end portion in the drawing) in the width direction of each pattern, it is possible to draw patterns having different line widths while fixing the pitch N. The two ends of the pattern P0 are on a grid. The left end portions of the patterns P1 to P9 are offset from the grids at the upper and right end portions thereof.

In addition, when drawing the evaluation pattern, it is preferable to turn off the correction functions such as distortion correction of the blanking aperture array substrate 24 and deflection correction of the substrate 40 in advance. In this case, since the pattern data of the evaluation pattern is arranged at the start coordinates of the mesh dividing the drawing area into pixels, and the drawing data is created and drawn so that the arrangement pitch of the pattern data is an integral multiple of the mesh, complete drawing on the grid can be performed, and thus evaluation of deviation on/from the grid with higher accuracy can be performed by comparison with this. Further, the deviation on the grid and the deviation from the grid of the multiple channels may be evaluated by drawing the deviations on the grid and the deviations from the grid in an overlapping manner.

After such an evaluation pattern is drawn, development and etching treatment are performed, and the line width of the pattern formed on the substrate 40 is measured using an SEM (scanning electron microscope) or the like.

In the analysis step, the difference (Δ CD) between the measurement result of the line width and the design value is calculated. By sequentially plotting the calculated differences in the order of the pattern, a graph such as that shown in fig. 8 can be obtained, for example. In order to extract the fluctuation in a specific period in the difference distribution, FFT (fast fourier transform) processing is performed to calculate the spatial frequency. When the peak value of the spatial frequency is equal to or less than a predetermined threshold value, it is determined that the desired drawing accuracy can be achieved. When the peak value of the spatial frequency exceeds a predetermined threshold value, it is determined that there is a possibility that process variation, grayscale shift of a grayscale beam, focus shift, or the like occurs.

In this way, by drawing an evaluation pattern in which the size is changed little by little in a size smaller than the particle beam size, performing FFT processing on the measurement result of the size of the evaluation pattern, and confirming whether or not any cycle has not occurred, controllability of the gray-scale beam and resolving power can be evaluated easily and quantitatively.

The evaluation pattern shown in fig. 7 has been described with respect to an example in which the line width is increased by R/10 every time from N/2, but may be decreased by R/10 every time. The difference in line width of the evaluation pattern may not be R/10. The pitch of the evaluation pattern is not limited to N, and may be k × N (k is an integer of 2 or more). The line width to be a reference for evaluating the pattern is not limited to N/2, and may be j × N (j is an integer of 1 or more).

In the above-described embodiment, the description has been given of an example in which the line width is changed while the pitch of the evaluation pattern is fixed, but the pitch may be changed while the line width is fixed.

For example, as shown in fig. 9, an evaluation pattern having a line width of N/2 is drawn by changing the pitch to R/10 or more at the data resolution. That is, patterns P10 to P19 are repeatedly arranged so that the pitch of patterns P10 and P11 is N, the pitch of patterns P11 and P12 is N + R/10, the pitch of patterns P12 and P13 is N +2R/10,. cndot.. cndot., and the pitch of patterns P19 and P10 is N + 9R/10. For example, when the particle beam size R is 10nm, the pitch of the patterns differs by 1nm in order.

By adjusting the irradiation amount of the pixels at both ends in the width direction of each pattern, an evaluation pattern in which the line width is fixed and the pitch is gradually changed can be drawn. For example, the pattern P0 has ends on a grid. The left end of the pattern P11 is offset from the grid at the upper and right ends of the grid. Both ends of the patterns P12 to P19 are offset from the grids.

The line width of the drawn pattern is measured, and an abnormality in a specific period can be easily found from the spatial frequency of the distribution of the difference between the measurement result of the line width and the design value. The pitch of the drawing pattern is measured, and controllability of the drawing position can be evaluated based on the spatial frequency of the distribution of the difference between the measurement result and the design value.

The evaluation pattern may be a linear pattern formed by sequentially shifting the plurality of rectangular portions in the width direction by a shift width smaller than the particle beam size and connecting the plurality of rectangular portions in the longitudinal direction at a constant pitch.

For example, as shown in FIG. 10, the 1-line pattern P20 is a pattern in which rectangular portions C1 to C4 having a width of N/2 are connected by being shifted by R/10 in the width direction. That is, the rectangular portion C2 is shifted by R/10 in the width direction from the rectangular portion C1, the rectangular portion C3 is shifted by 2R/10 in the width direction from the rectangular portion C1, and the rectangular portion C4 is shifted by 3R/10 in the width direction from the rectangular portion C1. A plurality of patterns P20 are depicted at a predetermined pitch N.

By adjusting the irradiation amount of the pixels at both ends in the width direction of each rectangular portion, a linear pattern can be drawn in which the rectangular portions are connected while being shifted. Both ends in the width direction of the rectangular portion C1 of each pattern P20 are on a grid. Both ends in the width direction of the rectangular portions C2 to C4 of each pattern P20 are offset from the grids.

The line width of each rectangular portion of the drawn pattern is measured, and an abnormality in a specific period can be easily found from the spatial frequency based on the difference between the measurement result of the line width and the design value. Further, by considering the line width measurement result of the rectangular portion C1 having both ends on the grid, the influence of the distortion of the blanking aperture array substrate 24 can be removed.

The evaluation pattern may be drawn by multiple drawing. In the drawing at the 1 st time and the drawing at the 2 nd time, the pixels having the end portions on the grid and the pixels having the end portions deviated from the grid may be interchanged. The evaluation pattern is not limited to a line shape, and may be a contact hole pattern, for example, as long as it has a certain line width.

The present invention is not limited to the above-described embodiments, and can be embodied by modifying the components in the implementation stage without departing from the scope of the invention. Further, various inventions can be formed by appropriate combinations of a plurality of constituent elements disclosed in the above embodiments. For example, several components may be deleted from all the components disclosed in the embodiments. Further, the constituent elements in the different embodiments may be appropriately combined.