JP3072564B2 - Arbitrary angle figure generation method in charged particle beam exposure method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for generating an arbitrary angle figure in a charged particle beam exposure method.

[0002]

2. Description of the Related Art In recent years, ICs have become more highly integrated and more sophisticated, are widely used in all industrial fields such as computers, communication devices, and machine controls, and are expected to play a role as core technologies. Such high integration and high functionality are due to advances in fine processing technology, the center of which is light exposure technology.
It extends to the submicron range. However, with optical technology, it is very difficult to open a small electrode window, and it is very difficult to achieve alignment accuracy of about 0.15 μm or less. Microfabrication techniques of 0.5 μm or less have not yet been formed by light exposure, and microfabrication techniques utilizing charged particle beam exposure centered on electron beams have become mainstream.

In the conventional pattern generation method using a variable rectangular beam, only a rectangle, a right-angled isosceles triangle, and a parallelogram having an angle of 45 degrees have been used. However, as the degree of integration of memories such as DRAMs increases, the occupied area of memory cells decreases more and more in order to increase the packing density. With only a non-rectangular shape (triangle, parallelogram, and trapezoid) having a rectangle and a hypotenuse of 45 degrees as before, the occupied area cannot be reduced, and a figure having an arbitrary angle is required.

In order to satisfy such demands, as a conventional example of a method of generating a pattern having an arbitrary angle other than 45 degrees, in an electron beam exposure apparatus shown in FIG. A large number of patterns having an arbitrary angle other than 45 degrees are created by using the magnetic tape 5.
3. The necessary pattern is stored in a memory means such as the magnetic disk 52 or the like, and is temporarily stored in the data memory 55 based on an instruction from the computer CPU. After that, the pattern data is supplied to the exposure apparatus through the pattern generation circuit 56 and the pattern correction circuit 57 in the next stage.

Since such an operation is performed for each pattern, it takes time to select a pattern and perform an exposure process.
Since it is necessary to create and store patterns (mainly triangles) having any arbitrary angles deemed necessary, the memory capacity has to be enormous. Furthermore, in the conventional method, as described above, there are many types of triangles with arbitrary angles, and having a pattern generation function for each type complicates the control unit, and the circuit scale for realizing it is enormous. It has become something.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art and to provide a method for efficiently generating an accurate arbitrary angle figure.

[0007]

The present invention employs the following technical structure to achieve the above object. That is, in generating a pattern having an arbitrary angle using a variable rectangular charged particle beam in the charged particle beam exposure method, a recording unit that stores information regarding the size of the input pattern, the starting point coordinate information of the input pattern Recording means for storing, a pitch memory for determining a size of a rectangular charged particle beam in a scanning direction and a non-scanning direction conforming to an input pattern according to a predetermined pattern rule, and a size of a rectangular beam stored in the pitch memory. 1 to be exposed based on the information and the starting point coordinate information
Means for calculating a coordinate value for each of the rectangular beams or a plurality of rectangular beams, and at least one of a size in the X-axis direction or the Y-axis direction and a starting coordinate value of the rectangular beam in accordance with arbitrary angle generation information In addition to providing a multiplier that can be changed independently, a pattern of a predetermined specific shape is selected and input as an original pattern in order to obtain a desired pattern, and the size and the starting point coordinates are specified to specify the pattern. Calculate data relating to the size and the coordinate value of one or a plurality of rectangular beams to be exposed necessary for generating the data, and then calculate the data using information corresponding to a predetermined arbitrary angle. This is an arbitrary angle figure generating method in a charged particle beam exposure method in which an arbitrary angle figure is generated by processing with a multiplier.

[0008]

In the present invention, a pattern having a predetermined rectangular beam size is generated by using only standard angle figures such as right-angled isosceles triangles, and a starting point coordinate and a beam size of each rectangular beam are multiplied by a multiplier. By multiplying by tanθ, which is information representing an arbitrary angle, a figure having an arbitrary angle with high accuracy can be generated without using a complicated control system.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. First, the configuration and operation of the electron beam exposure apparatus used in the present invention will be briefly described.

FIG. 9 shows a standard pattern, that is, an angle of 9 on a sample such as a wafer provided on a sample table 66 using a charged particle beam.
This shows a general exposure apparatus for forming a pattern composed of 0 degrees and 45 degrees, in which an electron gun 61 and a sample stage 66 are provided in a column 65, and an appropriate electron optical system is provided therebetween. A variable rectangular beam size adjuster 62, a sub deflector 63, and a main deflector 64 are arranged between the electron optical systems. On the other hand, the CPU 51, which is an arithmetic processing unit for pattern control, extracts necessary information from a data recording unit such as a magnetic disk 52 or magnetic tape 53 storing pattern information (pattern shape, size, coordinate data), and an interface. The data is recorded in the data memory 55 which also functions as a data buffer via the
Each beam size adjuster 62 through 56 and the pattern correction unit,
Digital / analog converters 58, 5 each having a corresponding amplifier for operating the sub deflector 63 and the main deflector 64
The necessary information is sent to each of 9 and 60, and a beam is emitted to perform exposure.

In such an apparatus, when a normal non-rectangular pattern is to be drawn, it is divided into elongated strips as shown in FIGS. 5A and 5B, and the strip-shaped rectangle is further maximally determined by a pattern rule. A method of drawing while dividing by a beam size and sequentially processing each column, and first dividing a triangle into a rectangle (particularly a square) and a small triangle by a pattern rule as shown in FIGS. 5C and 5D. Then, there is a method of further dividing the small triangle into strips. Here, the pattern rule is a method for determining the maximum beam size that can be emitted in one shot at the time of beam exposure. When the pattern size is determined, and when the beam size is determined, the number of shots and the beam size at that time are determined. Is automatically determined.

For example, if the maximum length of a pattern is 5 μm when the beam length is 2 μm,
The number of shots is 3, and the beam length of each shot is determined to be 1.667 ... According to such rules, the number of shots of the beam and the pattern length at that time when the beam length and the pattern length are variously deflected are calculated in advance and stored in the pitch memory. This beam size is in the X-axis direction,
It can be obtained in each of the Y-axis directions.

In general, since the exposure time in the variable rectangular charged particle beam exposure is almost proportional to the number of shots, a portion that can be shot with a large rectangle (without exceeding the maximum beam size) is shot with a rectangle as large as possible. However, when the remaining small triangular portion is shot with a beam size that gradually decreases in the non-scanning direction, the number of shots decreases and the processing time can be reduced. Here, a method of dividing the triangle into rectangles and small triangles will be described. However, the same method can be applied to a method of dividing the rectangle into strips.

Now, generate the pattern shown in FIG.
The case where scanning is performed in the X-axis direction
You. The pattern to be generated is a right-angled isosceles triangle
And the length of both sides is X_Two, Y_TwoCondition. here
X from pitch memory_TwoDivided into three, for example, S_XThe maximum
Set as the frame length. Therefore, the small
Triangle, A₁, A_Two, A_ThreeNon-scan direction, that is, Y-axis direction
Variable rectangular beam size (length) S_YIf is constant
As shown in FIG. 8 (A), the strip-shaped portions are reduced line by line.
The length ΔX is the same for all strip-shaped portions. on the other hand
Rectangular part B₁, B _Two, B_Three, One side of which is the largest short
Size S of one shot of book-shaped beam_XEqual to and other
The sides have the same size. The beam width S in the Y-axis direction_YAfter
The non-rectangular pitch memory described
Can direction length Y_TwoIs determined by equally dividing
You.

The lower left corner O of the above pattern is defined as a starting point,
The coordinates of the starting point (X ₁ , Y ₁ ) are stored in the memory, and a coordinate system is formed on the basis of these coordinate values for all rectangular or strip patterns generated thereafter.

From the above information, the coordinate positions of the tips of the plurality of strip-shaped variable rectangular beams are set such that the starting point is (X ₁ , Y ₁ ) and the starting point coordinate values (X ₁₂ , Y ₁₂ ), (X ₁₃ , Y ₁₃ )
Are obtained, and by connecting them, the pattern of the small triangular portion is completed. On the other hand, for the rectangular portions B ₁ , B ₂ , and B ₃ , a square pattern is obtained from the size of the beam width S _X , and this beam is exposed at each location. For the non-rectangular portions (small triangular portions) A ₁ , A ₂ , and A ₃ , each of the predetermined strip-shaped beams obtained above is exposed to draw a final triangular pattern. In the case of scanning in the Y direction, the procedure is completely reversed.

Here, the case of generating an arbitrary angle figure based on the above triangle will be described with reference to FIG. In the present invention, in the above-described conventional method, a pattern shape having an arbitrary angle is easily generated, and the basic technical idea is to use a triangular pattern having a desired size as a standard angle ( That is, select a pattern having 45 degrees),
According to the pattern rule, a required number of rectangular beads and a required number of non-rectangular beams composed of strip-shaped beams are created according to the pattern rule, and the size or starting point coordinate value of each beam represents an arbitrary angle. By multiplying the angle information, that is, tanθ, a triangle pattern having a desired arbitrary angle can be created.

A first embodiment according to the present invention will be described below with reference to FIG. The basic concept of generating an arbitrary-angle figure in the first specific example of the present invention is as follows. In generating a triangular pattern as described above, each time the length and coordinate value of the right rectangular beam are obtained, the X-axis or Y-axis direction is obtained. Is multiplied by information corresponding to an arbitrary angle, for example, tan θ, to obtain the size and coordinate value of each strip-shaped beam to obtain the final shape. X for a standard square figure
₂ = Y ₂ and an arbitrary angle tanθ = 1, but at an arbitrary angle, for example, a tangent from 0 to 90 degrees
If it is specified by, it becomes 0 to ∞, and a fine angle cannot be specified.

That is, in the present invention, in performing the above-described data processing, it is necessary to perform processing while suppressing all the processed data to a predetermined number of bits in order to reduce the memory capacity. For example, 8 bits or 1
A fixed data structure such as 6 bits is adopted. Therefore, when the value of tan θ is 45 ° or more, the number of data increases considerably, and it becomes difficult to perform accurate data processing. In addition, cutting with an appropriate number of bits may cause an error.

Therefore, in the present invention, the above-mentioned drawback can be solved by using the device in a state where the value of tan θ is always 1 or less, that is, 45 ° or less, as a basic technical configuration.
Therefore, in the present invention, an arbitrary angle to be processed depends on the shape and angle of a desired triangular pattern to be generated.
It is necessary to determine the scan direction for the standard angular triangular pattern so that tan θ is 1 or less.

First, as shown in FIG. 8A, the starting point coordinates O (X ₁ , Y ₁ ) of the triangular pattern are respectively stored in registers (RE).
G) Store in 1 and 2. This coordinate value (X ₁ , Y ₁ ) is compared with a subtraction value in the X direction or Y direction output from a multiplier 11 or 12 described later, and the start coordinate value of each rectangular beam is sequentially adjusted by addition or subtraction. Will be updated. On the other hand, the sizes X ₂ and Y ₂ of the triangle are registered in registers (REG) 3 and 4 respectively.
To memorize. Next, the input right triangle size X ₂ ,
Each rectangle B ₁ shown in Figure 5 (C) by Y _2, B _2, A ₁ of B ₃ and the small triangular portion, A _2, the beam size of the A ₃ X
Accessing the axial pitch memory 5 or the Y-axis pitch memory 6 maximum value S _X of the beam size of each portion is determined.

In the small triangle, first, the size of the lowermost rectangle is the same as the length S _X of the rectangle in the X direction, and the size S _Y in the Y direction is a non-rectangular pitch memory 7 for calculating a non-rectangular beam size. Is obtained by accessing (constant value). The calculation in the X-axis or Y-axis direction of the non-rectangular pitch memory is tanθ
Can be switched by operating the switch 20 by the output of the control signal generator in accordance with the condition that is 1 or less.
From the next stage onward, each of the strip-shaped beams sequentially has the size Sx in the X-axis direction.
Is controlled by the output of the control signal generator 8 into an arbitrary angle register (RE
G) The data of 9 is input to the multiplier 12 via the switch 10,
ΔX = S _Y × tan θ via the register 41 and the subtractor 43
The pattern is formed by subtracting each time (see FIGS. 6A and 6B).

When scanning in the Y-axis direction, a multiplier is used.
You only need to enable 11. As a result, the beam size in the X direction is changed to an appropriate size when an arbitrary angle is used, and the coordinate values (X _1n , Y _1n ) of each beam are also corrected by the output of the multiplier to be suitable for a predetermined arbitrary angle figure. Will be displayed.

In this specific example, the X of each strip beam is
Since the tan θ is multiplied every time the length change ΔX in the direction is calculated, the error increases, and the pattern eventually includes a considerable error, and the problem that an accurate pattern cannot be generated can be avoided. Absent. Therefore, as a second specific example according to the present invention, a method for improving the first specific example is provided. When a triangle pattern having an arbitrary angle is generated, for example, a right-angled isosceles triangle is used as a specific shape. And inputting only the pattern size X ₂ , Y ₂ and the starting point coordinates (X ₁ , Y ₁ ), and based on the information, a plurality of rectangular rectangular patterns of an appropriate size are selected. A triangle pattern consisting of a combination with a rectangular (square) pattern is generated. At the end, a process of multiplying tanθ as arbitrary angle information by the X-axis or Y-axis data to generate a triangle pattern having an arbitrary angle at once is performed. The rectangular beam and the strip-shaped beam of each portion obtained in this manner are sequentially exposed to form a final arbitrary angle pattern.

Hereinafter, a second specific example according to the present invention will be described with reference to FIGS. 2 and 5C. First, a standard angle figure is generated. The method of generating the standard angle figure is based on the X-axis and Y-axis sizes X ₂ and Y ₂ of the input figure as shown in FIG. By accessing the pitch memories 5 and 6 for determining the beam size,
Find the beam size. (Where, since the standard angle figure, a X ₂ = Y ₂ and tan .theta = 1.) This size S _X of the beam size of the rectangular portion B ₁ .about.B ₃ is determined. In this case, the switch 21 according to the scanning direction, or
Keep 22 enabled.

[0026] For small triangular portion A ₁ to A ₃ simultaneously also determined by accessing the non-rectangular pitch memory 7 the size S _Y in the non-scanning direction actuates the switch 20. On the other hand, the strip beam size in the scanning direction at the bottom of the small triangle is the same as the beam size S _X recorded in the X-direction pitch memory. From the above information, a plurality of beams necessary for drawing a right-angled isosceles triangle pattern can be immediately generated by calculation, and the coordinate values and beam sizes of each beam are recorded in a memory (not shown). Specifically, the X direction length S _X1 of the lowermost rectangular rectangular beam of the small triangular portion is the same as the value S _X of the rectangular pitch memory 5, and the Y direction length is the non-rectangular pitch memory 7. _{Is the} same as the value S _Y.

[0027] As the second stage shown in FIG. 8 (A), the value in the X direction obtained by subtracting using subtractor 44 the beam size S _y in the Y direction register 41 and the subtracter 43 or the register 42 S _X2 = outputs the S _X1 -S _y. This is sequentially repeated to output the uppermost rectangle. Thereafter, by operating the switch to multiply the output in the X direction, that is, only the beam size and the position coordinate, by the arbitrary angle tan θ to obtain the final output, a small triangle having an arbitrary angle is formed as shown in FIG. it can. Here, similarly to the small triangle, a triangle having an arbitrary angle can be formed by simultaneously multiplying only the X-direction component of the rectangular portion by the arbitrary angle tan θ to obtain a final output. Here, the following can be considered as the input data format of the arbitrary angle figure.

Operation code Start point X ₁ Start point Y ₁ 16 bits 16 bits 16 bits Size X ₂ Size Y ₂ Arbitrary angle tanθ 16 bits 16 bits 16 bits

The operation code used in the present invention includes a figure mode (standard angle figure, arbitrary angle figure, etc.), figure shape code, exposure dose correction code, and the like. The data of the small triangular portions A ₁ , A ₂ , A ₃ in this embodiment are shown as follows.

[0030]

[0031]

In the present invention, the length in the non-scanning direction (width of the strip beam) output from the non-rectangular pitch memory
Is preferably as small as possible in order to clean the hypotenuse of the triangle, but if the number is too large, the number of shots increases, so it should be set to an appropriate value, but it is said that about 0.2 μm is good. If the desired pattern is a parallelogram having an arbitrary angle, the size of the X-axis and the Y-axis may be similarly obtained from the rectangular pitch memory, and finally processed by multiplying by tan θ.

In the present invention, as described above, in order to increase the efficiency of the arithmetic processing for generating a pattern, data of only one of two orthogonal sides (X direction or Y direction) of a right-angled isosceles triangle and a coordinate start point ( X ₁ , Y ₁ ) may be used for the calculation, and finally the data in the X-axis direction and the Y-axis direction may be calculated using the switch.

FIG. 3 shows a third specific example of the arbitrary-angle pattern generating method according to the present invention in order to execute the above technical idea. In this specific example, two sides X ₂ and Y ₂ of a right-angled isosceles triangle are X
_{Using the fact that 2} = Y ₂ and tan θ = 1, the size of a right angle isosceles triangle of standard angle (length of one side)
Using only S, the rectangular and non-rectangular pitch memories 5 and 7 are simultaneously accessed to determine the beam sizes of the rectangular and small triangles in the non-scanning direction, respectively.

Finally, in the same manner as in the second embodiment, the switch 24 is enabled in either the X-axis direction or the Y-axis direction by using a control signal to control tanθ as arbitrary angle information with respect to the position coordinates and the beam size. As a result, multiplied arbitrary angle figures can be obtained using the multipliers 31 to 34. As input graphic data in this embodiment, data S on one side of a standard right-angled isosceles triangle may be given. That is, it can be described by the following five words.

Operation code Start point X ₁ Start point Y ₁ Size S Arbitrary angle tanθ 16 bits 16 bits 16 bits 16 bits 16 bits

Therefore, the memory capacity required for data processing can be greatly reduced. Furthermore, in the present invention, the efficiency can be further improved by using a plurality of types of shape codes related to a triangular pattern in combination with the above-mentioned method and combining a switch. A fourth specific example of the arbitrary angle figure generating method for executing the technical idea according to the present invention will be described with reference to FIG.

In this example, only one kind of standard angle right-angled isosceles triangle is generated, and a rectangular beam size _Sr is output from a rectangular pitch memory 5 based on its size S, and a non-rectangular pitch memory 7 is used. in outputting the non-scanning direction of the beam size S _t. Information on an arbitrary angle in the beam size and coordinate value of one of the X direction and the Y direction obtained in the following
After multiplying by tan θ, the final output is switched from the control signal generation circuit having the shape code by using the switches 25 to 28, and one or both of the data of the X axis and the Y axis are exchanged or the polarity is reversed according to the shape code. This generates an arbitrary angle figure.

That is, in the first to third embodiments, the original triangular pattern is determined in advance up to the arrangement direction and the processing is performed. In the present embodiment, however, only one means for generating the standard angle triangle is provided. 7 can be generated using the shape code.

That is, the direction of the pattern to be generated is not determined simply by inputting the beam size and the coordinates of the starting point for the triangle having the standard angle. Therefore, in this specific example, 8 as shown in FIG.
Various types of triangular patterns are prepared, a shape code is given to each of them, and the following data is provided. When using the shape code in this specific example, it is assumed that the beam size always changes from a large beam size to a small beam size. (The direction of the arrow in FIG. 7) The reference position of the starting point coordinates of each pattern is set to the zero point of each pattern.

[0041]

[Table 1]

[0042] It is.

[0043]

As described above, when the present invention is used, it is possible to easily form precise triangles of various angles at various angles without having a complicated control system and without increasing the memory capacity. In addition, it is possible to construct a pattern generation unit that generates the data in a short time.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first example of an arbitrary-angle figure generating method according to the present invention;
6 is a block diagram showing a specific example of FIG.

FIG. 2 is a diagram showing a second example of the arbitrary-angle figure generating method according to the present invention;
6 is a block diagram showing a specific example of FIG.

FIG. 3 is a block diagram showing a third specific example of the present invention.

FIG. 4 is a block diagram showing a fourth specific example of the present invention.

FIG. 5 is a diagram showing an example of a standard angular triangle.

FIG. 6 is a diagram illustrating an example of an arbitrary-angle triangle;

FIG. 7 is a diagram illustrating an arbitrary triangular figure and its shape code;

FIG. 8 is a diagram for explaining the principle of generation of a small triangle;

FIG. 9 is a configuration diagram of a general charged particle beam exposure apparatus.

[Explanation of symbols]

 1-4, 9, 13, 14, 19 ... registers 5, 6 ... rectangular pitch memory 7 ... non-rectangular pitch memory 8 ... control signal generator 10, 20, 21, 22, 24, 27, 28, 45, 46 ... Switch 15, 16, 17 ... Subtractor 31, 32, 33, 34, 35, 36 ... Multiplier 40 ... Shape code generator 51 ... Control computer 52 ... Magnetic disk 53 ... Magnetic tape 54 ... Interface 55 ... Data Memory 56 ... Pattern generation unit 57 ... Pattern correction unit 58 ... D / A converter amplifier (beam size) 59 ... D / A converter amplifier (sub deflection) 60 ... D / A converter amplifier (main deflection) 61 ... Electron gun 62 ... Beam size deflector 63 ... Sub deflector 64 ... Main deflector 65 ... Electronic optical column 66 ... Sample stage

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Yasuda 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Kazutaka Taki 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited ( 72) Inventor Kenichi Miyazawa 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Automation Limited (56) References JP-A-57-53935 (JP, A) JP-A-3-116922 (JP, A) Hei 3-270216 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/027

Claims (7)

(57) [Claims] When a pattern having an arbitrary angle is generated using a variable rectangular charged particle beam in a charged particle beam exposure method, a recording means for storing information on the size of the input pattern, a starting point of the input pattern Recording means for storing coordinate information, a pitch memory for determining the size of a rectangular charged particle beam in a scanning direction and a non-scanning direction according to a predetermined pattern according to a predetermined pattern rule, and a rectangular beam stored in the pitch memory. Means for calculating a coordinate value for each of one or more rectangular beams to be exposed from the size information and the start point coordinate information, and the size of the rectangular beam in the X-axis direction or the Y-axis direction And multiplication that can independently change at least one of the starting point coordinate values according to the arbitrary angle generation information In order to obtain a desired pattern, a pattern having a predetermined specific shape is selected and input as an original pattern, and the size and the starting point coordinates are specified. Calculating data relating to the size and the coordinate value of one or a plurality of rectangular beams to be exposed, and then processing the calculated data by the multiplier using information corresponding to a predetermined arbitrary angle; An arbitrary-angle figure generating method in a charged particle beam exposure method, wherein an arbitrary-angle figure is generated by the following. 2. A basic rectangular beam to be exposed first among one or a plurality of rectangular beams to be exposed necessary for generating an original pattern of a specific shape selected to obtain a desired pattern. The size and the coordinate value of the starting point are calculated, and for the rectangular beam to be exposed next, at least one of the size and the coordinate value of the starting point is calculated by the multiplier using the arbitrary angle generation information. Then, the above calculation method is repeated to calculate the size of each of the required number of rectangular beams and the coordinate value of each starting point, and finally, based on the information on all the rectangular beams obtained above, each rectangular beam is calculated. 2. The method for generating an arbitrary-angle figure according to claim 1, wherein the exposure processing is performed individually or simultaneously. 3. After calculating a size and a coordinate value of a starting point for each of one or a plurality of rectangular beams required to generate an original pattern of a specific shape selected to obtain a desired pattern, After combining the obtained information on all the rectangular beams, at least one of the size and the coordinate value of the starting point of each rectangular beam is processed by the multiplier using the arbitrary angle generation information,
2. The method according to claim 1, wherein an exposure process is performed after changing the size of the whole rectangular beam and the coordinate value of the starting point. 4. The method according to claim 1, wherein an isosceles right triangle is used as the original pattern having the specific shape.
The method of generating the arbitrary angle figure described. 5. A non-rectangular pitch memory for calculating a maximum value of a size of a rectangular beam forming a rectangular portion and a non-rectangular shape for calculating a length of a rectangular beam forming a non-rectangular portion in a non-scanning direction. 5. The method for generating an arbitrary-angle figure according to claim 1, further comprising a pitch memory. 6. An arbitrary-angle figure generating method according to claim 1, wherein an arbitrary-angle figure is formed by using only a starting point position coordinate and a beam size in one of the X-axis direction and the Y-axis direction. . 7. The method according to claim 1, further comprising using a shape code for displaying a specific triangular shape.