JP4373660B2 - Drawing position control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is related to the drawing position control system of the drawing apparatus having a circular pattern generator.
[0002]
[Prior art]
The existing electron beam lithography system only specifies the dose (charged particle beam dose), the center position and radius of the circle when specifying a circle pattern when drawing a circle, and the circle drawing start position is fixed. The number of times the circle is drawn is fixed to once (one round).
Patent Document 1 describes a circle drawing apparatus using an electron or ion beam, and Patent Document 2 describes a circle pattern drawing apparatus. These relate to a circular pattern generator and are not described for a three-dimensional shape. The existing electron beam drawing apparatus is designed for use in applications such as two-dimensional drawing such as semiconductor processes and production of the same exposure mask.
Non-Patent Document 1 does not describe drawing of a circular pattern, but describes shape prediction of a three-dimensional shape created by electron beam drawing.
[0003]
[Patent Document 1]
JP-A-8-273583 [Patent Document 2]
Japanese Patent Laid-Open No. 11-109906 [Non-patent Document 1]
Optics 29, 9 (2000), p 566-572 “Effectiveness and limitations of electron beam proximity effect correction for diffractive optical element fabrication”
[0004]
[Problems to be solved by the invention]
At present, there is no charged particle beam lithography system designed and manufactured exclusively for manufacturing three-dimensional shapes, and existing two-dimensional shape manufacturing charged particle beam lithography devices are used for three-dimensional shape manufacturing. Has been.
The method of drawing a circle using a circle pattern generator in a charged particle beam drawing device is more accurate than a method of drawing a circle by a polygon approximation method or the like, but the drawing start point is the drawing end point. For this reason, the dose amount near the drawing start point varies due to the calculation error of the drawing position at the start of drawing and at the end of drawing, the control error, etc. As shown in FIG. 3A, the drawing start point and drawing end point of the circle 1 Is slightly separated to create a gap 2 between the drawing start point and the drawing end point, or the drawing start point and the drawing end point of circle 1 overlap slightly and overlap as shown in FIG. When the part 3 is formed or a three-dimensional shape is manufactured, a shape error 5 of the three-dimensional shape 4 occurs as shown in FIGS. 3B and 4B.
[0005]
Further, when a plurality of circles having the same center and different radii are drawn continuously, the drawing start positions of the circles 1 are arranged as shown in FIG. Continuously, the error from the desired shape of the part becomes large.
The present invention aims to provide Hisage the drawing position control method capable of improving the shape accuracy of the 3-dimensional shape.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a drawing position control method for a drawing apparatus having a circular pattern generator, wherein a plurality of circles having the same center and different radii are used by using the circle pattern generator. When drawing a circle, the circle pattern generator is controlled so as to shift the drawing start position of the circle from the drawing start position of another circle close to the circle. The shift amount of the circle from the drawing start position is set to a shift amount corresponding to an angle at which the circumference cannot be equally divided into a plurality of circles .
[0007]
According to a second aspect of the present invention, in the drawing position control system of a drawing apparatus having a circle pattern generation device, when drawing a plurality of circles having the same center and different radii using the circle pattern generation device, The circle pattern generator is controlled so as to shift the drawing start position of the other circle from the drawing start position of another circle close to the circle, and the drawing start position of the circle and the drawing start position of another circle adjacent to the circle, The shift amount is set using a random number or a pseudo-random number .
The invention according to claim 3 is a drawing position control method of a drawing apparatus having a circle pattern generator, and when drawing a plurality of circles having the same center and different radii using the circle pattern generator. The drawing position control method in which a circle is drawn a plurality of times without ending one round and the drawing position control method according to claim 1 or 2 are used in combination .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 shows a reference embodiment 1 of the present invention. This reference embodiment 1 is one reference embodiment of a charged particle beam drawing apparatus having a circular pattern generator. As the charged particle beam generator 11 that generates a charged particle beam, for example, an electron gun that generates an electron beam is used, but an ion beam gun that generates an ion beam may be used. The blanking deflector 12 arbitrarily turns on and off the electron beam emitted from the electron gun 11, and the beam shaping diaphragm 13 shields an unnecessary portion of the electron beam that has arrived from the electron gun 11 through the blanking deflector 12. Then, the beam is shaped into a desired shape.
[0011]
The electron beam shaped by the beam shaping diaphragm 13 is converged by the electron lenses (groups) 14 and 15 and deflected in the X direction and the Y direction by the deflector 16 to be placed at an arbitrary position on the substrate 17 to be drawn. Irradiated. Here, the X direction and the Y direction are two directions orthogonal to each other in a plane perpendicular to the traveling direction of the electron beam emitted from the charged particle beam generator 11. The substrate 17 is set and positioned on the positioning stage 18, and a circle is drawn by the electron beam.
[0012]
A control CPU 19 as a control unit controls each of the units 20 to 23 based on drawing data input from the outside. The exposure control unit 20 controls the blanking deflector 12 based on the exposure control data from the CPU 19 or the exposure control signal (or data) from the circle pattern generator 21. The X / Y deflector drive unit 22 outputs a drive signal to the deflector 16 based on the X / Y drawing data from the CPU 19 and the X / Y circle drawing signal (or data) from the circle pattern generator 21 to deflect the deflector. 16 is driven.
[0013]
The circle pattern generator 21 sequentially applies an exposure control signal (or data) and an XY circle drawing signal (or data) necessary for drawing one circle based on the circle drawing data from the CPU 19 to the exposure control unit. 20 and XY deflector drive unit 22. The stage drive unit 23 drives the positioning stage 18 based on the stage drive data from the CPU 19.
[0014]
Figure 2 is an optical product using a charged particle beam drawing apparatus of the present reference embodiment 1 (optical element, for example, a micro lens convex as shown in FIG. 10), a diagram for explaining a case of fabricating a product, such as the mold is there. In the case of manufacturing an optical product, the substrate 17 is manufactured by applying an electron beam resist 25 on an optical material substrate 24 such as quartz, glass material, sapphire, or silicon as shown in FIG. In this case, a metal material is used as the material for the substrate 24.
[0015]
The substrate 17 is in a charged particle beam drawing apparatus of the present reference embodiment 1 as described above, is drawn by an electron beam with a dose to match the desired shape as shown in FIG. 2 (b), thereby ready to serve The shape accuracy of the optical element (or mold) is increased.
Next, the electron beam resist 25 on the substrate 24 is developed and formed into a three-dimensional shape as shown in FIG. Next, based on this three-dimensional shape, the shape is transferred onto the substrate 26 by etching as shown in FIG. 2D, and an optical element as shown in FIG. 2E or as shown in FIG. A predetermined product 27 is manufactured using a mold as shown in FIG. In this case, the charged particle beam drawing apparatus of the present reference embodiment 1, the shape of the circle X = X0, Y = Y0 radius r centered against the substrate 17 of a plurality of radius of r = 1～R0 Draw as an aggregate. When a donut shape is drawn on the substrate 17 as an aggregate of a plurality of circles having a radius of r = r1 to r0, the initial r = 1 is set to r = r1. Further, instead of the microlens convex as shown in FIG. 10 as the optical element, a microlens concave as shown in FIG. 11, an aspherical microlens as shown in FIG. 12, a diffractive optical element as shown in FIG. It can also be produced in the same way.
[0016]
A charged particle beam drawing apparatus of the present reference embodiment 1 is sequentially shifted by FIG. 6 (a) and FIGS. 7 (a) or angle theta a drawing start position of a plurality of circles 1 to draw as shown in θrnd (θ Random) As a result, the gap 2 between the drawing start point and the drawing end point of the circle 1 and the overlapping portion 3 near the drawing start point and the drawing end point of the circle 1 are distributed over the entire figure, so that The variation in dose amount is dispersed, the shape error of each part of the plurality of circles 1 is reduced, and the shape error 5 of the three-dimensional shape 4 is reduced.
[0017]
Figure 8 shows the operation flow for shifting the drawing start point of this preferred embodiment 1, Figure 9 shows a circle drawn in the present reference embodiment 1, the dose of each circle, the example of manufacturing the three-dimensional shape. When the initial drawing start angle for drawing a series of circles is θ0, and the shift angle of the drawing start position to be shifted once is Δθ, the CPU 19 first sets r = 1 (unit is a charged particle beam drawing apparatus) in step s1. The drawing start angle θsl of the first circle is set to θ0, and the dose Dr in the current drawing is set in accordance with the radius r of the circle as shown in FIG. calculate. Here, the dose amount Dr is an exposure control value (electron beam irradiation amount) in drawing a circle with each radius r in accordance with the shape to be created.
[0018]
Next, in step s3, the CPU 19 sets the drawing start angle θsr of the circle to be drawn next time to θs (r−1) + Δθ, and shifts the drawing end angle θer of the circle to be drawn next time from the drawing start angle θsr by 360 °. Set to an angle. Next, in step s4, the CPU 19 uses the circle center position (X0, Y0), the radius 1 of the circle to be drawn this time, the calculated dose amount D1, the drawing start angle θs1 of the circle to be drawn this time, and the circle drawing data as step s4. The drawing end angle θe1 is output to the circle pattern generator 21.
[0019]
The circle pattern generator 21 sequentially outputs an exposure control signal (or data) and an XY circle drawing signal (or data) necessary for drawing one circle based on the circle drawing data from the CPU 19 to the exposure control unit 20. And output to the XY deflector drive unit 22. The exposure control unit 20 controls the blanking deflector 12 based on the exposure control signal (or data) from the circular pattern generator 21 to turn on the electron beam emitted from the electron gun 11.
[0020]
The X / Y deflector drive unit 22 drives the deflector 16 based on the X / Y circle drawing signal (or data) from the circle pattern generator 21 to deflect the electron beam in the X direction and the Y direction. A circle 17 having a radius 1 centered on (X0, Y0) is drawn by an electron beam with a drawing start angle θs1 and a drawing end angle θe1. Next, the CPU 19 increments r in step s5, and determines whether r is greater than r0 in step s6.
[0021]
If r is not larger than r0, the CPU 19 returns to step s2, and calculates the dose Dr in the next drawing according to the radius r of the circle. Next, in step s3, the CPU 19 sets the drawing start angle θsr of the circle to be drawn next to θs (r−1) + Δθ, and sets the drawing end angle θer of the circle to be drawn next to 360 ° from the drawing start angle θsr. Set to a shifted angle. Next, in step s4, the CPU 19 sets the circle center position (X0, Y0), the radius 2 of the circle to be drawn next, the calculated dose amount D2, and the drawing start angle of the circle to be drawn next in step s4. θs2 and the drawing end angle θe2 are output to the circular pattern generator 21. As a result, a circle of radius 2 centered on (X0, Y0) with a dose amount D2 is drawn on the substrate 17 by the electron beam as described above, with the drawing start angle θs2 and the drawing end angle θe2.
[0022]
Thereafter, the CPU 19 repeats the process in the same manner and outputs circle drawing data to the circle pattern generator 21, whereby a plurality of circles with respective radii centered on (X0, Y0) are sequentially drawn on the substrate 17 by the electron beam. The drawing is performed by shifting the start angle and the drawing end angle. When the drawing of the circle with the radius r0 centering on (X0, Y0) is finished and r becomes larger than r0, the CPU 19 finishes the process without returning from step s6 to step s2. The drawing order of a plurality of circles may be such that the change of the radius r is the reverse order (r0 to 1).
[0023]
According to this reference embodiment 1, when drawing a plurality of circles with different radii have the same center, the circle pattern to shift the drawing start position of the circular from the drawing start position of another circle close to the circle generated Since the device is controlled, that is, the drawing start positions of a plurality of circles are sequentially shifted, the variation in dose at the drawing start position can be distributed over the entire figure, and the shape error of each part can be kept small. be able to. For this reason, the shape accuracy of the three-dimensional shape of the optical element or mold can be improved, and the optical performance of the optical element can be enhanced.
[0024]
FIG. 14 shows an operation flow for shifting the drawing start point of Reference Embodiment 2 of the present invention, and FIG. 15 shows an example of a circle drawn in Reference Embodiment 2, a dose amount of each circle, and a manufactured three-dimensional shape. In this preferred embodiment 2, in the above Reference Embodiment 1, the operation flow shown in FIG. 14 in place of the operation flow CPU19 is shown in FIG. That is, in step s11, the CPU 19 fixes the drawing start angle θs when drawing a series of circles to an arbitrary angle θ0, and sets the drawing end angle θe to n times 360 ° from the drawing start angle θ0 (n is 2 or more). (Integer) of rotated angle.
[0025]
Next, in step s12, the CPU 19 calculates the dose Dr in the current drawing according to the radius r of the circle as shown in FIG. Next, in step s13, the CPU 19 uses the circle center position (X0, Y0), the radius 1 of the circle to be drawn this time, the calculated dose amount D1, the drawing start angle θs and the drawing end angle θe as circle drawing data. Output to the circle pattern generator 21. As a result, a circle having a radius of 1 centered at (X0, Y0) with a dose amount D1 is drawn on the substrate 17 by rotating around the drawing start angle θs and drawing end angle θe several times.
[0026]
Next, the CPU 19 increments r in step s14, and determines whether r is greater than r0 in step s15. If r is not larger than r0, the CPU 19 returns to step s12, and calculates the dose Dr in the next drawing according to the radius r of the circle. Next, in step s13, the CPU 19 uses the circle center position (X0, Y0), the radius 2 of the circle to be drawn this time, the calculated dose amount D2, the drawing start angle θs and the drawing end angle θe as the circle drawing data. Output to the circle pattern generator 21. As a result, a circle of radius 2 centered at (X0, Y0) with a dose amount D2 is drawn on the substrate 17 by a plurality of rounds with the drawing start angle θs and the drawing end angle θe.
[0027]
Thereafter, the CPU 19 repeats the process in the same manner and outputs the circle drawing data to the circle pattern generator 21, whereby a plurality of circles each having a radius centered at (X 0, Y 0) are sequentially formed on the substrate 17 by the electron beam. Each lap is drawn. When the drawing of the circle with the radius r0 centering on (X0, Y0) is finished and r becomes larger than r0, the CPU 19 finishes the process without returning from step s15 to step s12. The drawing order of a plurality of circles may be such that the change of the radius r is the reverse order (r0 to 1).
[0028]
According to this reference form 2, for example, when n = 2, as shown in FIG. 18A, a small gap is formed between the drawing start point and the drawing end point of the circle 1, and FIG. As shown in FIG. 5, the shape error 5 of the three-dimensional shape 26 occurs. However, by drawing the circle a plurality of times instead of ending once, the variation in the dose amount at the drawing start position is relatively small. Therefore, the shape error can be kept small. For this reason, the shape accuracy of the three-dimensional shape of the optical element or mold can be improved, and the optical performance of the optical element can be enhanced.
[0029]
FIG. 16 shows an operation flow for shifting the drawing start point of Reference Embodiment 3 of the present invention, and FIG. 17 shows an example of a circle drawn in Reference Embodiment 3, a dose amount of each circle, and a manufactured three-dimensional shape. When the initial drawing start angle for drawing a series of circles is θ0, and the shift angle of the drawing start position to be shifted once is Δθ, the CPU 19 first sets r = 1, the first circle drawing start angle in step s21. θsl is set to θ0, and in step s22, the dose Dr in the current drawing is calculated according to the radius r of the circle as shown in FIG.
[0030]
Next, in step s23, the CPU 19 sets the drawing start angle θsr of the circle to be drawn next time to θs (r−1) + Δθ, and sets the drawing end angle θer of the circle to be drawn next time to 360 ° from the drawing start angle θsr. Double (n is an integer of 2 or more). Next, in step s4, the CPU 19 uses the circle center position (X0, Y0), the radius 1 of the circle to be drawn this time, the calculated dose amount D1, the drawing start angle θs1 of the circle to be drawn this time, and the circle drawing data as step s4. The drawing end angle θe1 is output to the circle pattern generator 21. As a result, a circle having a radius of 1 centered at (X0, Y0) is drawn on the substrate 17 by an electron beam, with a drawing start angle of θs1 and a drawing end angle of θe1.
[0031]
Next, the CPU 19 increments r in step s25, and determines in step s26 whether r is greater than r0. If r is not larger than r0, the CPU 19 returns to step s22, and calculates the dose amount Dr in the next drawing according to the radius r of the circle. Next, in step s23, the CPU 19 sets the drawing start angle θsr of the circle to be drawn next to θs (r−1) + Δθ, and sets the drawing end angle θer of the circle to be drawn next to 360 ° from the drawing start angle θsr. Is set to an angle rotated by n times. Next, in step s24, the CPU 19 sets the circle center position (X0, Y0), the radius 2 of the circle to be drawn next, the calculated dose amount D2, and the drawing start angle of the circle to be drawn next in step s24. θs2 and the drawing end angle θe2 are output to the circular pattern generator 21. As a result, a circle of radius 2 centered at (X0, Y0) with a dose amount D2 is drawn on the substrate 17 by a plurality of rounds with a drawing start angle of θs2 and a drawing end angle of θe2 as described above. The
[0032]
Thereafter, the CPU 19 repeats the process in the same manner and outputs circle drawing data to the circle pattern generator 21, whereby a plurality of circles with respective radii centered on (X0, Y0) are sequentially drawn on the substrate 17 by the electron beam. Drawing is performed in multiple rounds by shifting the start angle and the drawing end angle. When the drawing of the circle with the radius r0 centering on (X0, Y0) ends and r becomes larger than r0, the CPU 19 ends the process without returning from step s26 to step s22. The drawing order of a plurality of circles may be such that the change of the radius r is the reverse order (r0 to 1). When the CPU 19 designates the drawing end angle θe as a relative angular movement amount from the drawing start angle θs, the drawing end angle θe is fixed to n times 360 °.
[0033]
According to this reference embodiment 3, with shifting the drawing start position of the circular from the drawing start position of another circle close to the circle, the drawing of a circle, it is performed orbiting multiple times without end with one rotation, FIG. than the reference embodiment 1, as shown in 19 can be suppressed further shape error small, it is possible to improve the shape accuracy of the 3-dimensional shape 26 of the optical element and the mold.
[0034]
Embodiments of the present invention, in the above-described Reference Embodiment 1 or 3, to set the shift angle Δθ of the drawing start position, the angle can not be divided the circumference integer number (angle be divided circumferentially not an integer) Therefore, it is possible to avoid the drawing start positions of circles that are shifted from each other by several from being close to each other.
[0035]
In an embodiment of the present invention, in the above embodiment 1 or 3, CPU 19 is intended to shift angle Δθ of the drawing start position, and to set randomly by using a random number (or pseudo random number), several mutually It can be avoided that the drawing start positions of the shifted circles are close to each other.
The present invention is directed to a three-dimensional processing apparatus having a circular pattern generator that performs drawing using a charged particle beam, and an exposure apparatus for producing a three-dimensional shape using a non-charged particle beam such as a converged laser beam. The same can be applied to the above.
[0036]
【The invention's effect】
As described above, according to the present invention, the variation in dose at the drawing start position can be reduced, the shape error can be suppressed, and the shape accuracy of the three-dimensional shape can be improved.
[Brief description of the drawings]
1 is a schematic diagram showing a reference embodiment 1 of the present invention.
2 is a diagram for explaining a case of fabricating a product, such as optical products, mold using a charged particle beam drawing apparatus of the reference embodiment 1.
FIG. 3 is a diagram for explaining a method of drawing a circle using a conventional circle pattern generator.
FIG. 4 is a diagram for explaining a method of drawing a circle using a conventional circle pattern generator.
FIG. 5 is a diagram for explaining a method of drawing a circle using a conventional circle pattern generator.
FIG. 6 is a diagram for explaining a method of drawing a circle using a conventional circle pattern generator.
FIG. 7 is a diagram for explaining a method of drawing a circle using a conventional circle pattern generator.
8 is a flowchart showing an operation flow for shifting the drawing start point of the Reference Embodiment 1.
FIG. 9 is a diagram showing an example of a circle drawn in the above-described reference embodiment 1, a dose amount of each circle, and a manufactured three-dimensional shape.
FIGS. 10A and 10B are a plan view and a side view showing an example of convex microlenses. FIGS.
FIGS. 11A and 11B are a plan view and a side view showing an example of a concave microlens. FIGS.
FIGS. 12A and 12B are a plan view and a side view showing an example of an aspherical microlens. FIGS.
FIG. 13 is a plan view and a side view showing an example of a Fresnel lens.
14 is a flowchart showing an operation flow for shifting the drawing start point of the reference embodiment 2 of the present invention.
FIG. 15 is a diagram illustrating an example of a circle drawn in the same reference form 2, a dose amount of each circle, and a manufactured three-dimensional shape.
16 is a flow chart showing an operation flow for shifting the drawing start point of the reference embodiment 3 of the present invention.
FIG. 17 is a diagram showing an example of a circle drawn in the reference embodiment 3, a dose amount of each circle, and a manufactured three-dimensional shape.
FIG. 18 is a diagram for explaining the reference embodiment 2;
FIG. 19 is a diagram for explaining the reference embodiment 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Charged particle beam generator 12 Blanking deflector 13 Beam shaping diaphragm 14, 15 Electron lens 16 Deflector 17 Substrate 18 Positioning stage 19 Control CPU
20 Exposure Control Unit 21 Circular Pattern Generator 22 X / Y Deflector Drive Unit 23 Stage Drive Unit

Claims (3)

  In the drawing position control system of a drawing apparatus having a circle pattern generation device, when drawing a plurality of circles having the same center and different radii using the circle pattern generation device, the drawing start position of the circle is set to the circle. The circle pattern generation device is controlled so as to shift from the drawing start position of another adjacent circle, and the amount of shift between the drawing start position of the circle and the drawing start position of another circle adjacent to the circle is set to the circumference. A drawing position control system characterized in that a shift amount corresponding to an angle that cannot be equally divided into a plurality of parts is set.   In the drawing position control system of a drawing apparatus having a circle pattern generation device, when drawing a plurality of circles having the same center and different radii using the circle pattern generation device, the drawing start position of the circle is set to the circle. The circle pattern generator is controlled so as to shift from the drawing start position of another adjacent circle, and the amount of shift between the drawing start position of the circle and the drawing start position of another circle adjacent to the circle is set to a random number or a pseudo value. A drawing position control method characterized by setting using a random number. A drawing position control method for a drawing apparatus having a circle pattern generator, wherein when a plurality of circles having the same center and different radii are drawn using the circle pattern generator, a circle is drawn once. several times a writing position control method in which circulating to, drawing position control method, characterized in that the combined use of drawing position control method according to claim 1 or 2 without end with.

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