JPH025406A - Charged particle beam lithography - Google Patents

Abstract

PURPOSE:To improve a lithography speed and to enhance the operability of a lithography device by obtaining a time required for the lithography of a frame region on the basis of various information obtained by the calculation of lithography pattern data, and calculating an optimum table moving speed from this time. CONSTITUTION:The number of lithography unit graphics are calculated for each subfield region 54 which forms a field region 60 (60a-60c), and the total sum of the number of the lithography unit graphics in each sub field region 54 is obtained as the number of the lithography unit graphics contained in the region 60. The maximum value of the number of the graphics contained in the region 60 is recognized as a field having highest pattern density of a frame region 53. A time required for the lithography process of the region 60 is calculated. The length L of the region 53 in the table continuously moving direction is divided by this time thereby to determine the table moving speed. Thus, the productivity of an LSI can be improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a charged beam for drawing patterns of semiconductor integrated circuits such as LSIs on samples such as masks and wafers at high speed and with high precision. The present invention relates to a lithography method, and particularly to a charged beam lithography method that improves lithography throughput by optimizing table movement speed.

(Prior Art) In recent years, LSI patterns have become increasingly finer and more complex, and electron beam lithography equipment has been used as a device for forming such patterns.

When drawing a desired pattern using this device, CA
Design data created using an LSI pattern design tool such as D cannot be supplied as drawing data to the above-mentioned drawing apparatus in its original format. The reason for this is that (D) design data is generally expressed as a polygon (7), whereas the data used in an electron beam lithography system only allows basic shapes such as a trapezoid or a rectangle.

■If the figures overlap each other, multiple exposure will occur and the drawing accuracy will deteriorate.

(2) The data used for 71i child beam lithography must be divided into unit lithography areas based on the lithography method.

This is due to this.

Therefore, by performing contouring processing on the above design data to remove multiple exposures, and then dividing it into basic shapes such as a rectangle and a trapezoid for each unique region (frame region) determined by the beam deflection region, the electronic By the process of making the graphic data acceptable to the beam writing device,
Drawing pattern data related to the integrated circuit is generated and stored in a storage medium such as a magnetic disk.

Then, the drawing pattern data is read out for each frame area and temporarily stored in a pattern data buffer,
This data is decoded and divided into a collection of drawing unit figures that can be formed. Then, while controlling the beam position and beam shape based on the results, the table on which the sample is placed is continuously moved in the X direction or the Y direction to draw a desired pattern within the frame area. Next, the table is moved in steps by the width of the frame area in a direction perpendicular to the continuous movement direction, and the above process is repeated to perform the drawing process on the entire desired area.

In addition, in the two-stage deflection method in which the main deflection means determines the sub-deflection position and the sub-deflection means performs drawing, a frame area is composed of a collection of unit drawing areas (subfields), and the width of the frame area is determined by the main deflection means. It is defined by the beam deflection width. In this method as well, the drawing pattern data is read out for each frame area, and drawing processing is performed while continuously moving the table.

As mentioned above, in the drawing process, the table movement speed when drawing a frame area is determined by the patterning time (time to draw a desired pattern by controlling the position and shape of the beam) of all drawing unit figures in the frame area. It must be a value that can sufficiently follow the table movement speed mentioned above. The following two methods have been used to determine the table movement speed that satisfies this condition.

(2) When drawing a frame area, set an extremely low table movement speed so that patterning can sufficiently follow the table movement speed, and perform drawing processing at this movement speed over the entire frame area.

■Before patterning a sample such as a mask or way I\, move the table to avoid buttering errors (errors that occur when the nocturning process is unable to follow the table movement speed) for each frame area that makes up the drawing area. The speed is found and set using a trial and error method, and the drawing process is executed using the table movement speed.

However, this type of method has the following problems. That is, when determining the table movement speed when drawing the frame area, in the method of The table movement speed must be set to a value that is lower than the table movement speed that allows high frame areas to be drawn without error. Therefore, in frame areas other than the frame area, drawing is performed at a lower table movement speed than necessary, resulting in an extremely large amount of wasted time in the drawing time of the entire LSI chip.

On the other hand, in the method (2), it is possible to perform drawing processing with less waste for each frame area that constitutes the LSI chip, but in order to determine the table speed, it is necessary to As pre-processing for placing the image on the table, it is necessary to repeat trial and error for each frame area to determine a table movement speed that can minimize wasted drawing time. The time spent on the above process in the entire drawing process cannot be ignored, and in some cases, the time required to determine the table movement speed may be longer than the time required for the actual drawing process. could be.

Under these circumstances, in the current drawing process, the drawing time increases, that is, the throughput decreases due to the method of determining the table movement speed for each frame area. and,
As mentioned above, the problem will reduce the operation rate of the electron beam lithography system and cause a decrease in the productivity of LSI.In the future, with the rapid progress of LSI, patterns will become finer and the degree of integration will increase. This poses a major problem in increasing the reliability of LSI patterns drawn with a beam drawing device and the operating rate of the device.

(Problems to be Solved by the Invention) Conventionally, when drawing is performed at a sufficiently slow table movement speed that does not cause drawing errors, the drawing time is greatly lost and the drawing throughput is significantly reduced. on the other hand,
In the drawing process in which drawing is performed by finding a table movement speed that minimizes the loss during drawing, time is spent in the preprocessing process to determine the table movement speed, which lengthens the time for the entire drawing process. Therefore, there was still a problem that the sloop rate decreased.

Furthermore, the above-mentioned problems are not limited to electron beam lithography methods, but apply to all charged beam lithography methods in which a desired pattern is formed on a sample using a charged beam such as an ion beam.

The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to eliminate the preprocessing process of repeating trial and error to determine the table movement speed of each frame area that constitutes an LSI chip. To provide a charged beam drawing method that can determine a substantially optimal tape moving speed for each frame area in consideration of pattern density, thereby optimizing drawing speed and improving throughput. be.

[Structure of the Invention (Means for Solving the Problems) The gist of the present invention is to obtain the time required to draw a frame area based on various information obtained from drawing pattern data through simple calculations, and to calculate the optimal time from this time. The purpose of this method is to calculate the table movement speed, and in particular, to divide the frame area into virtual field areas and find the optimal table movement speed in the field area.

That is, the present invention divides the drawing area on the sample into frame areas determined by the beam deflection width of the main deflection means, and continuously moves the table on which the sample is placed for each frame area. The charged beam is sequentially positioned in the unit drawing area within the frame area, and the charged beam is deflected within the unit drawing area by the sub-deflection means to form a collection of drawing unit figures that can be formed by the beam shaping means. In the charged beam drawing method for drawing the unit drawing area, the frame area is virtually divided into field areas of a predetermined length in the table movement direction, and the field areas included in the field areas constituting the frame area are Find the time required to draw the field area from the number of drawing unit figures in the field area with the largest number of drawing unit figures;
In this method, the frame area is subjected to drawing processing using the table movement speed obtained by dividing the length of the field area by this time (claim 1).

Further, the present invention divides the drawing area on the sample into frame areas determined by the beam deflection width of the main deflection means, and continuously moves the table on which the sample is placed for each frame area, while the main deflection A charged beam is sequentially positioned in a unit drawing area within the frame area by a means, the unit drawing area is expressed as a collection of drawing unit figures that can be formed by a beam shaping means, and the unit drawing area is drawn by a sub-deflection means. In the charged beam drawing method, the frame area is virtually divided into field areas of a predetermined length in the table movement direction, and the frame area is virtually divided into field areas of a predetermined length based on the number of drawing unit figures included in the field areas constituting the frame area. Find the time required to draw each field area, divide the length of the field area by these times to calculate the optimum movement speed of the table in each field area, and calculate the optimum movement speed for each field area. In this method, the table movement speed is accelerated or decelerated based on the drawing process (Claim 2).
).

(Function) According to the method according to claim 1 of the present invention, the field area is determined based on the number of unit drawing figures included in the field area with the highest pattern density among the field areas obtained by virtually dividing the frame area. Find the time required to draw the area,
By performing the drawing process for the frame area using the table movement speed obtained based on this time, there is no need for preprocessing to find the optimal value of the table movement speed through trial and error prior to the actual drawing process. Therefore, a substantially optimal table movement speed can be easily determined for each frame area. As a result, it becomes possible to increase the operating rate of the charged beam lithography apparatus and to improve the productivity of LSI.

Furthermore, the above-described drawing method is expected to be more effective in achieving finer patterns and higher integration as LSI advances rapidly in the future.

Further, according to the method according to claim 2 of the present invention, for each field area obtained by virtually dividing the frame area, the optimum moving speed of the table calculated based on the number of drawing unit figures included in the field area is calculated. By performing drawing processing while accelerating or decelerating the table, the above-mentioned pre-processing is not necessary, and the averaged table movement speed can be increased compared to the method described in claim 1, thereby further improving LSI productivity. It becomes possible to do so.

(Example) Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

FIG. 1 is a schematic configuration diagram showing an electron beam lithography apparatus used in an embodiment of the method of the present invention (an embodiment of the charged beam lithography method according to claim 1). In the figure, reference numeral 10 denotes a sample chamber, and a table 12 on which a sample 11 such as a semiconductor wafer or a glass mask is placed is accommodated in the sample chamber 10. The table 12 is driven by a table drive circuit 13 in the X direction (left and right directions on the page) and in the X direction (front and back directions on the page). The moving position of the table 12 is measured by a position circuit 14 using a laser length meter or the like.

An electron beam optical system 20 is arranged above the sample chamber 10. This optical system 20 includes an electron gun 21 and various lenses 2.
2 to 26, blanking deflector 31, beam dimension variable deflector 32, beam scanning main deflector 33, beam scanning sub-deflector 34, and beam shaping aperture 35.3
It is composed of 6th grade. Then, it is positioned in a predetermined unit drawing area (subfield) by the main deflector 33,
The sub-deflector 34 positions the figure drawing surface within the sub-field, and the beam dimension variable deflector 32
The beam shape is controlled by the shaping apertures 35 and 36, and the frame area is drawn while the table 12 is continuously moved in one direction.

Further, the table 12 is moved stepwise in a direction perpendicular to the direction of continuous movement, and the above process is repeated to sequentially draw each frame area.

On the other hand, the control computer 40 has a magnetic disk (recording medium) 4.
1 is connected, and LSI chip data is stored in this disk 41. Chip data read from the magnetic disk 41 is temporarily stored in a pattern memory (data buffer section) 42 for each frame area. The pattern data for each frame area stored in the data buffer unit 42, that is, the frame information consisting of drawing positions, basic figure data, etc., is analyzed by a pattern data decoder 43 and a drawing decoder 44, which are data analysis units, and blanking is performed. Circuit 45 Beamformer driver 46. Main deflector driver 47 and sub deflector driver 4
Sent to 8th.

That is, the pattern data decoder 43 receives the above data and performs inversion processing on the graphic data included in the frame area as necessary to generate inverted pattern data.

Next, the basic figure data defined as frame data is divided into drawing unit figure groups that can be formed by the combination of the forming apertures 35 and 36, and blanking data is created based on this data. It is sent to the ranking circuit 45. Further, desired beam size data is created and sent to the beam shaper driver 46. Next, a predetermined deflection signal is applied from the beam shaper driver/f driver 46 to the beam size variable deflector 32 of the optical system 20, thereby controlling the size of the electron beam.

Furthermore, the drawing data decoder 44 creates subfield positioning data based on the frame data, and sends this data to the main deflector driver 47.

Then, a predetermined signal is applied from the main deflector driver 47 to the main deflector 33 of the optical system, whereby the electron beam is deflected and scanned to a designated sub-feed position. moreover,
The drawing data decoder 44 generates a control signal for scanning the sub-deflector, and this signal is sent to the sub-deflector driver 48. Then, a predetermined sub-deflection signal is applied from the sub-deflector driver 48 to the sub-deflector 34, thereby performing drawing for each sub-field.

Next, an electron beam lithography method using the apparatus configured as described above will be explained. FIG. 2 shows the process of generating data for performing the drawing process.

LSI patterns are designed and created using a CAD system, and the design pattern data is converted into drawing data by a host computer. Then, this writing data is read out and electron beam writing is performed.

Here, the data created by the CAD system is usually a graphic data system in which the pattern is composed of a group of polygonal figures, and patterns are allowed to overlap each other. In order to make this type of LSI pattern data into a data system that can be accepted by an electron beam lithography system, a post-computer performs contouring processing on the figure, removes the beam multiple exposure area, and then processes the data as shown in Figure 3 ( As shown in a),
The chip area is divided into frame areas 53a to 53d, which are unit drawing areas in which the beam can be deflected, and a subfield area 54. FIG. 3(b) shows drawn figures in the subfield region 54, which are made into polygons 51 and 52 by removing the beam multiple exposure region. Next, this drawn figure is divided into a basic figure group 56 consisting of rectangles and trapezoids as shown in FIG. 3(C).

The graphic data obtained through such a data generation process is expressed using a graphic shape flag, a graphic position, and a graphic size, and is defined as a graphic data group in subfield area and frame area units and stored on the magnetic disk 41.

The drawing pattern data created through such a data generation process is then stored on the magnetic disk 41 for each frame area.
The chip area of the LSI is a mixture of areas with low pattern density and areas with high pattern density that continuously change. Therefore, the time required for patterning differs for each frame area that makes up the chip area, and it is therefore desirable to optimize the table movement speed during patterning, which is set for each frame area, from the perspective of improving throughput. It will be done.

Therefore, the basic figure data divided into the frame area and subfield area as shown in FIG. 3(e) as described above is read out for each frame area, and the control computer 40 forms the data as shown in FIG. 4(a). A graphic system as shown in FIG. 4(b) is used, which is expressed by a collection of drawing unit graphics 59 that can be formed by introducing the apertures 57 and 58.

On the other hand, the frame area 53 (53a to 53d) is
The field head 60 (60a) is determined by the beam deflection width of the main deflector 33 with respect to the table movement direction.

5Qb, 60c). Then, the number of drawing unit figures is calculated for each field area. That is, the number of drawing unit figures is calculated for each subfield area constituting the field area, and the sum of the number of drawing unit figures in each subfield area is determined as the number of drawing unit figures included in the field area. Then, the maximum value of the number of drawing unit figures included in the field area is recognized as the field with the highest pattern density in the frame area.

Next, the local patterning time is calculated by multiplying the maximum number A of drawing unit figures included in the field area by the sum of the beam setting time Q and the beam irradiation time P for each drawing unit figure. Furthermore, assuming that the subfield areas are virtually arranged in a matrix in the field area, the number B of subfields included in the field area is obtained, and the number B of subfields is multiplied by the positioning time R for each subfield area. Then, the total subfield positioning time within the field is calculated. From the sum of these times, the time T required to draw the field area with the highest pattern density in the target frame area is calculated. Then, by dividing the length L of the frame area in the table continuous movement direction by this time T, the table movement speed S is determined.

The table movement speed S obtained in this manner is approximately the optimum table movement speed for each frame area, taking into account the pattern density. Note that if multiple types of LSI chips are arranged in a mixed manner in one frame area, the table movement speed is determined by performing the above processing on each LSI chip, and the table movement speed that is the lowest among them is selected. Let's select the speed.

Through the processing steps described above, by determining the table movement speed for each frame area and performing the drawing process using that table movement speed, wasted time in the drawing process can be significantly suppressed, and as a result, the drawing process Throughput can be improved.

Thus, according to the method of this embodiment, it is possible to eliminate the need for a preprocessing step of searching for the optimum table movement speed that involves driving the table, which is performed prior to the actual drawing process, and significantly reduces wasted time in a series of drawing steps. We were able to significantly improve drawing throughput. Also,
The conventional apparatus itself can be used as is, and it has the advantage that it can be easily realized by simply adding a step of calculating the table movement speed during patterning as a pre-processing for frame drawing.

Next, another embodiment method of the present invention (one embodiment of the charged beam drawing method according to claim 2) will be described. In this embodiment, the table movement speed is controlled for each field area to perform more optimal drawing processing. The structure of the electron beam lithography apparatus is almost the same as that shown in FIG. 1, except that a signal for giving table acceleration/deceleration commands is supplied from the lithography data decoder 44 to the table drive circuit 13, as shown by the broken line in FIG. It has become.

The process of dividing figures into a basic figure group 56 consisting of rectangles and trapezoids as shown in FIG. 3(c) is the same as in the previous embodiment. In this embodiment, such data generation],
The figure data obtained in the step 7 is expressed by a figure shape flag, figure position, and figure size, and defined as a figure data group for each subfield area, and when constructing frame data as a set of data lj1, 53
As shown in FIG. 5 (field areas 60a to 60c)
The data in subfield area 5 and ↓ are divided into respective field areas.

Then, as shown in FIG. 6, the subfield data)f
- A configuration in which frame and ivy information is added to a set of field data that is expressed as a set for each field and defines the total area of drawings and figures included in each area of the field meeting. l) 7 frame information to the magnetic disk 4
Store in 1. The total area of the drawing diagram 116 is obtained by calculating the drawing area for each subfield area in the process of dividing the polygonal figure into basic figure groups, and then summing this value for the field area. When reading the drawing pattern data created through the numerical data generation process from the magnetic disk 4 for each frame area and drawing, the LSI chip area has continuous areas with low pattern density and areas with high pattern density. They are mixed while changing. Therefore, the time required for bettering differs for each frame area that makes up the chip area, and accordingly, the table movement speed must be constantly optimized for each full gnome and even within a frame when performing drawing processing. is desired.

Therefore, as shown in FIG. 6, the frame information is read out for each frame area 7 and temporarily stored in the pattern L 42, and the frame data is The drawing data decoder 44 recognizes the total drawing area of figures in the field. The number A of drawing unit figures included in the field area is roughly estimated by dividing by the beam dimension value.Furthermore, the beam setting time Q and beam irradiation time P for each drawing unit figure are added to the number A of drawing unit figures. The local patterning time of the field is calculated by multiplying the field area by the subfield positioning time R. Calculate the total positioning time. Divide the length of the field area by the added value T of these times to determine the local table movement speed S within the field. Furthermore, this table movement speed S is calculated for each field. decided on.

”AX (P+Q) 10 BXR Then, the numerical value ΔS obtained by subtracting the current table movement speed from this S is sent to the table drive circuit 13 as an increment from the current table movement speed, as shown by the solid line in FIG. The table speed is accelerated or decelerated for each center of the field area to perform drawing processing.The above acceleration or deceleration is distinguished by the sign of ΔS, and the current table position is always used for drawing. The beam position is monitored and corrected for each figure to be drawn, and the O table tracking correction is performed.

Furthermore, when the drawing figure shown in FIG. 3(C) is inverted by the pattern data decoder 43 and subjected to drawing processing in the basic figure system as shown in FIG. Then, from this value, the total image area β1 before inversion processing described in the field data section is subtracted to calculate the total area β2 of the drawing figure for the inversion pattern. Then, based on this β2, the table speed S and speed increment ΔS for each field are derived by the same Fp process as described above, and acceleration/deceleration control is performed.

If it is not possible to accelerate or decelerate to the table speed calculated for each field due to constraints on table acceleration/deceleration, the table speed will be adjusted based on the table speed setting for fields up to multiple lights so as not to exceed the table speed. By controlling the acceleration and deceleration of V2 by changing V2 to V2' as shown by the broken line in FIG. 7, the same effect as described above can be obtained.

Through the processing steps described above, when drawing each frame area, the main deflection means performs the drawing process by accelerating or decelerating each deflectable field at a constant acceleration, thereby significantly reducing wasted time in the drawing process. As a result, the throughput of drawing processing can be improved. Therefore, the same effects as in the previous embodiment can be obtained, and more optimal drawing processing than in the previous embodiment can be performed.

Note that the present invention is not limited to the embodiments described above. For example, the means for storing the chip data is not limited to a magnetic disk, but other storage media such as a magnetic tape or a semiconductor memory can be used. Further, the preprocessing of dividing the basic figure group included in the frame area into drawing unit figure groups and determining the table movement speed may be performed by the host computer instead of the control computer. To find the highest field area, calculate the total drawing area for each field,
Based on this value, the field with the highest pattern density is identified, and only this field is divided into a group of drawing unit figures to derive the number of drawing unit figures, in the same manner as in the above embodiment. The table movement speed may also be determined.

Furthermore, the number of drawing unit figures is calculated by dividing the total drawing area of the field area by the average beam dimension value of the drawing unit figure without performing figure division, and also using a pattern data decoder. It may also be obtained by performing graphic division using

Further, the acceleration/deceleration control of the table may be performed at high speed for each field, and drawing processing may be performed at a substantially constant speed within the field. Furthermore, the acceleration/deceleration period can also be changed as appropriate in addition to the field area.

Furthermore, the configuration of the electron beam lithography apparatus is not limited to the same as that shown in FIG. 1, but can be modified as appropriate.

In addition, although the embodiments have been explained using an electron beam as an example, the application is not limited to electron beams, but can be applied to charged beams including ion beams, and the drawing method is also the main subject.
In addition to a two-stage deflection method that combines sub-deflection, a single-stage deflection method or a three-stage or more-stage deflection method may also be used. In addition to a shot method using a variable shaped beam, it is also applicable to a device method using a circular beam. It is possible. Furthermore, the graphic system of the drawing data stored in the storage medium is applicable not only to basic figures but also to drawing unit figures and polygonal figures.

In addition, various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] As detailed above, according to the present invention, the field region with the highest pattern density is identified from among the field regions obtained by virtually dividing the frame region, and the drawing unit included in the field region is By drawing the frame area at a table movement speed determined based on the number of figures, it is possible to significantly reduce wasted time in the drawing process, improve the drawing speed, and increase the operating rate of the charged beam drawing device. As a result, it is possible to contribute to improving LSI productivity. Moreover, the above effect can be further enhanced by determining the optimum table movement speed for each field area and controlling the table movement speed by acceleration/deceleration.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the configuration of an electron beam lithography system used in a method according to an embodiment of the present invention, Fig. 2 is a schematic diagram showing the process of generating drawing pattern data, and Fig. 3 is a schematic diagram showing the process of generating drawing pattern data. A schematic diagram showing figure division and area division of
Fig. 4 is a schematic diagram showing figure division into drawing unit figures from a pattern, Fig. 5 is a schematic diagram showing an example of field division, and Fig. 6 is a schematic diagram showing an example of field division.
7 is a schematic diagram showing the data structure of frame information, FIG. 7 is a schematic diagram for explaining table speed acceleration/deceleration control, and FIG. 8 is a schematic diagram showing a reversal pattern. DESCRIPTION OF SYMBOLS 10... Sample chamber, 11... Sample, 12... Table, 20... Electron optical system, 21... Electron gun, 22-
26... Lens, 31-34... Deflector, 35.3
6... Beam forming aperture, 40... Control computer, 41... Magnetic disk (recording medium), 42... Pattern memory (data buffer section), 43-... Pattern data decoder, 44... Drawing data decoder, 5
152...Polygon, 53 (5', 3a-53d)...
- Frame area, 54... Subfield (unit drawing area), 56... Basic figure group, 57.58... Aperture, 59... Drawing unit figure, 60 (60a to 6
0c)...Field area.

Claims (3)

[Claims] (1) The drawing area on the sample is divided into frame areas determined by the beam deflection width of the main deflection means, and while the table on which the sample is placed is continuously moved for each frame area, the main deflection means The charged beam is sequentially positioned in the unit drawing area within the frame area, and the charged beam is deflected within the unit drawing area by the sub-deflection means, and the unit drawing is performed as a collection of unit drawing figures that can be formed by the beam shaping means. In a charged beam drawing method for drawing a region, the frame region is virtually divided into field regions of a predetermined length in the table movement direction, and the drawing units included in the field regions constituting the frame region are The time required to draw the field area is calculated from the number of drawing unit figures in the field area with the largest number of figures, and the frame area is drawn using the table movement speed obtained by dividing the length of the field area by this time. A charged beam drawing method characterized by: (2) The drawing area on the sample is divided into frame areas determined by the beam deflection width of the main deflection means, and the table on which the sample is placed is continuously moved for each frame area, and charged by the main deflection means. Charged beam drawing in which a beam is sequentially positioned in unit drawing areas within the frame area, the unit drawing areas are expressed as a collection of drawing unit figures that can be formed by a beam forming means, and the unit drawing areas are drawn by a sub-deflection means. In the method, the frame area is virtually divided into field areas of a predetermined length in the table movement direction, and each field is divided based on the number of drawing unit figures included in the field areas constituting the frame area. The time required to draw each area is calculated, and the length of the field area is divided by these times to calculate the optimum moving speed of the table in each field area, and the table is drawn based on the optimum moving speed for each field area. A charged beam drawing method characterized in that drawing processing is performed by controlling acceleration or deceleration of a moving speed. (3) As a means for calculating the time T required for drawing the field area, the number of drawing unit figures in the field area is A, the beam irradiation time required for one drawing unit figure is P,
The beam setting time required for one drawing unit figure is Q, the number of unit drawing areas included in the field area is B, the time required for beam positioning to one unit drawing area is R, and T=A×(P+Q). 3. The charged beam drawing method according to claim 1, wherein the time T is calculated using the formula: +B×R.