JP3357160B2 - Electron beam drawing method and electron beam drawing system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam drawing method, and more particularly to an electron beam drawing method which is suitable for drawing relatively simple figures and which can be realized at low cost in terms of equipment cost. Further, the present invention also relates to an electron beam lithography system based on the electron beam lithography method.

[0002]

2. Description of the Related Art An electron beam drawing apparatus of this kind is used for producing an exposure mask for an exposure apparatus or for drawing an electronic circuit or a circuit element directly on a semiconductor element. As is well known, an electron beam drawing apparatus includes a drawing apparatus using a vector scanning method in which an electron beam is sequentially scanned and drawn according to various figures to be drawn, and an electron beam is scanned in horizontal and vertical directions. 2. Description of the Related Art A drawing apparatus using a frame scanning method similar to a so-called television scanning method is known.

[0003] These drawing apparatuses have been developed for drawing a semiconductor element actually used or a fairly complicated circuit for experiments. Therefore, a function that has a large storage capacity for storing complicated figures and can perform high-speed drawing processing is required for these drawing apparatuses. For this reason, an electron beam drawing apparatus using a vector scanning method is generally used.

However, there is a demand for producing a semiconductor circuit having a relatively small number of circuit elements or a simple figure on a laboratory scale. In that case, I don't want or need to spend a lot of money. When a commercial simplified scanning electron microscope is used without modification and a figure is drawn within a 0.5 μm point or line resolution range, the maximum figure range that can be drawn is about 100 μm ² . Compared to this simple scanning electron microscope that uses one-stage electron beam deflection, the electron beam scanning device that uses a 4-pole / 1-stage or 8-pole / 2-stage deflection, which is developed exclusively for electron beam drawing, uses the above-described drawing. Under the conditions, the maximum allowable figure range is at most about 500 μm ² and about 2 mm ² respectively. This range is determined mainly by the deflection aberration of the electron beam, and when the traveling direction of the electron beam is largely deflected, the electron beam converged in a point shape on the object to be drawn is distorted accordingly. This is because the current density of the electron beam incident on the drawing target decreases at the edge. In addition, if the deflection angle is large,
This is because the aperture or the like also reduces the transmittance of the electron beam in the electron optical system.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to draw a relatively simple figure, and to use an ordinary scanning electron microscope on hand without any modification to the electron microscope body. An object of the present invention is to provide an electron beam drawing method based on frame scanning, which can realize a relatively wide drawing range at a high cost, and an electron beam drawing system that executes the method.

[0006]

SUMMARY OF THE INVENTION The above-mentioned object is achieved by the present invention.
Input the figure data and divide the figure into individual figure elements.
Understand the types, coordinates, and locations of the graphic elements that characterize this figure
Frame figure data for electron beam scanning consisting of required parameters
Processing device 10 for outputting a desired drawing on a drawing target SP
Scanning electron microscope that performs drawing by irradiating an electron beam according to a picture figure
Scan supplied from the microscope 30 and the graphic processing device 10
A desired drawing figure based on the frame figure data for
Therefore, the electronic shutter SH of the scanning electron microscope 30 is
To activate the blanking output signal and the deflection coil DF
Using a scanning synchronization processing unit 20 that outputs a deflection scanning signal and
When scanning with an initial electron beam of constant intensity, the drawing object
Predict the electron current density reaching each individual scan area of
A plurality of gradations A according to the value of_0,A_1,A_Two...
Divide the boundary line S of each individual gradation area in the scanning frame._0,
S_1,S_TwoCreates a gradation graphic representing ...
10 and the floor where the figure to be processed in
Tone pattern, gradation A_0,A_1,A_Two... almost the same depending on
Electron beam scanning speed so that each scanning area is irradiated with the same amount of current
Degree C_0,C_1,C _Two... for each gradation A_0,A_1,A_Two... to
And set the electron beam scanning position to the corresponding gradation range in the frame.
You can irradiate the electron beam only when it is in the box and the desired drawing.
The electronic shutter SH is activated as described above, and
The deflection coil DF is scanned at a corresponding electron beam scanning speed, and
Scanning of all gradations A_0,A_1,A_Two... for
The problem is solved by the electron beam drawing method to be performed.

[0007] Further, according to the present invention, there is provided the above-described electron beam drawing method,
First, from the original drawing data supplied from the graphic processing device 10,
Original figure data generator 42 for creating an original figure for a frame, subsequent original figure storage unit 44, and gradation figure data generation for creating a gradation figure for one frame from gradation figure data supplied from figure processing apparatus 10. Based on the input signal of the gradation and the scan start and scan end signals supplied from the graphic unit 43, the gradation figure storage unit 45 subsequent thereto, and the figure processing device 10.
A timing circuit 47 for generating a scanning speed corresponding to each gradation, a scanning signal generator 48 which follows the timing circuit 47, and generates a scanning drive signal for driving the deflection coil DF from an output signal of the timing circuit 47; 44, a gradation figure storage unit 45 and a timing circuit 47,
This is solved by providing the electronic shutter SH with a blanking output circuit 46 which outputs a blanking output signal from these output signals in accordance with the corresponding gradient at each scanning position in the frame.

Further, according to the present invention, there is provided the above-described electron beam drawing method,
First, from the original drawing data supplied from the graphic processing device 10,
A figure generator for creating an original figure for a frame and creating a gradation figure for one frame from the gradation figure data, and is supplied from an original figure storage unit 44, a gradation figure storage unit 45, and the figure processing device 10 subsequent thereto. A timing circuit 47 for generating a scanning speed corresponding to each gradation based on an input signal of a certain gradation and a scanning start and scanning end signal. The timing circuit 47 follows the timing circuit 47, and drives the deflection coil DF from the output signal of the circuit 47. A scanning signal generator 48 for generating a scanning drive signal to be generated, and an original figure storage unit 44, a gradation figure storage unit 45, and a timing circuit 47, and from these output signals, the corresponding floor of each scanning position in the frame is obtained. This problem is solved by providing a blanking output circuit 46 that outputs a blanking output signal to the electronic shutter SH in accordance with the degree of adjustment.

Further advantageous configurations according to the invention are set out in the dependent claims.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings showing embodiments. FIG. 1 shows the entire system of an electronic drawing system according to the present invention. This system is roughly divided into three groups. That is, the main image processing unit 10, the image sweeping unit 20, and the hand-held scanning electron microscope 30. In this case, the scanning electron microscope 30 is a normal scanning microscope and is not an object of the present invention.

The main image processing unit 10 includes an input unit 2 composed of, for example, a keyboard and switches, a display unit 4 for displaying graphic data and various other data and monitoring input data at the time of input, and a large amount of data to be stored. A graphic parameter and command data related to the graphic parameter are inputted from an external storage device 6 such as a floppy disk, a hard disk or the like and the input unit 2 for temporarily storing the data and retrieving it when necessary. (A detailed description will be given below), various storage units (RAM, ROM) for storing required data and a control sequence program, microprocessors for performing digital operations, various I / Os. It is composed of a graphic processing main body 9 having an O interface and the like. The main image processing unit 10 may be constituted by a normal personal computer or a personal computer dedicated to graphic processing.

The scanning synchronization processing section 20 outputs a scanning signal for controlling the scanning electron microscope 30 and a blanking output signal in accordance with an output from the main image processing section 10, as will be described in detail later. This is for measuring the irradiation current at 30, and is a main component of the present invention.

The scanning electron microscope 30 may be an ordinary simple scanning electron microscope as described above, and FIG. 1 shows only the main parts directly related to the present invention. Electrons emitted from the electron gun G is focused onto the surface of the focused rendering target object SP in two focusing lenses L ₁ and L _2. Thus, in the ideal case, the electron optical axis OA
Are deflected so as to deviate from the electron optical axis OA by driving the deflection coil driving circuit 24 and the corresponding deflection coil DF. Therefore, the electron beam moves on the drawing target SP by a distance x from the electron optical axis OA. Although not shown, another deflection coil and another deflection coil driving circuit are also provided so as to be able to deflect also in the y direction orthogonal to the x direction. An electronic shutter SH corresponding to a beam stopper driven by the blanking output signal to prevent the electron beam from being incident on the drawing target SP.
And its drive circuit 22 are provided. In addition, an ammeter 26 is also provided in the scanning electron microscope 30 to measure the current incident on the drawing target SP.

Prior to a detailed description of the circuit of the scan synchronization processing section 20 which is important in the present invention, first, the basic principle of the drawing method according to the present invention will be described. As described above, the irradiation current density decreases at the edge of the scanning range due to the deflection aberration and restrictions on the apparatus due to the scanning of the electron beam. FIG. 2A is a schematic graph illustrating the distribution of the irradiation current density. When the x and y directions orthogonal to each other are respectively set as x and y axes, and the current density I is shown on the z axis with the electron optical axis OA as the origin, a bell-shaped irradiation current density is generated as shown in FIG. 2A. As is well known, the degree of curing of the electron beam resist irradiated at the time of writing or the removal rate when the semiconductor is etched by electron beam irradiation increases with the irradiation current density. According to FIG. 2A, the region A ₀ having the strongest irradiation current density is near the electron optical axis OA, and the regions A _1, A _2, ... a ₅ occurs. Therefore, in order to keep the degree of cure of the electron beam resist or the removal rate by electron beam irradiation almost constant in any irradiation region, the irradiation current is increased as the irradiation region deviates from the electron optical axis OA, or the scan line residence time is increased. Need to be longer. It is very difficult to increase or decrease the irradiation current at a high response speed. Therefore, according to the present invention, maintaining the irradiation current density constant with respect to the irradiation area is achieved by increasing the stay time of the electron beam, that is, by increasing the scanning time in the area. I have.

For this reason, as shown in FIG.
Current density area A_0,A_1,A_2,.... A_FiveIrradiation equivalent to
Area figure B_0,B_1,B_Two(The rest is omitted in the drawing.
) Is prepared corresponding to the graphic area to be actually drawn.
And area A_0,A_1,A_TwoOf average irradiation current density at
Is, for example, 1.00, 0.98, 0.96, the irradiation area B _0,
B_1,B_TwoTime ratios at 1.00, 1.02, 1.04
Adjust. Limit values of the ratio of these stay times, gradients, etc.
Of the material to be etched with an electron resist or electron beam
It is appropriately determined according to the type and the intensity of the incident current.

For example, three vertices α,
In the drawing in which the inside of the triangle formed by β and γ is filled, the scanning time is changed for each circle in accordance with the concentric circle centered on the point O corresponding to the electron optical axis OA. Drawing is performed while scanning in the x direction with a longer scanning time. Using the example described above, the ratio of residence time for electron beam scanning is 1.00 for the innermost circle (circle), 1.02 for the next outer circle (triangle), and next for the outer circle (cross). Is 1.04.

In the drawing according to the present invention, when a triangle as shown in FIG. 3 is drawn, one scan, that is, only one scan in the vertical (y) direction, is completed, but the number of gradations matches the selected number of gradations. 3, ie, in the case of FIG. 3, the drawing is completed by six vertical scans. For this purpose, for example, as shown in FIG. 5, electron beam scanning having different scanning times in the x direction is prepared. In other words, to scan the electron beam at a constant velocity in the x-direction from the starting point 0 of the figure to the end point L _M. These scanning speeds are the first scanning speed C _0, the second scanning speed C _1, the third scanning speed C _2.
・ ・ It becomes late in the order.

The operation to be actually performed to draw the figure shown in FIG. 3 will be described with reference to FIGS. 1, 2B and 4. In the first time scan to scan horizontally with the electron beam that is the slowest scanning speed in the x direction, i.e. at a scan rate C ₀ of FIG. That is, via the lead L ₁₂ from scan drive signal output terminal of the scan synchronization processing unit 20 of FIG. 1, applied to the scan deflection signal scanning coil driver circuit 24 of the sawtooth waveform, which corresponds to the scanning speed C ₀ in FIG. 4 The current-amplified drive signal is supplied to the deflection coil DF. At this time, the electronic shutter SH opens and allows the electron beam to pass only in the hatched area of B ₀ in FIG. 2B, and closes the electronic shutter SH to prevent the passage of the electron beam in the unhatched area ( Actually, the electron beam is largely deflected by a kind of electrostatic deflecting plate provided in the scanning electron microscope as the electronic shutter SH). This operation, the shutter signal blanking drive circuit feeding a 22 by way of the lead L ₁₁ from the output end for blanking signal of the scanning synchronization processing unit 20 of FIG. 1, the electronic shutter SH from the drive circuit 22 in accordance with this By giving a predetermined potential for blanking. In this first scan, the irradiation electron beam reaches only the circle at the center circle of the triangle αβγ in FIG.

Next, as a second scan, a scan signal having a sawtooth waveform corresponding to the slow scan speed C ₁ (FIG. 4) is supplied to the scan coil drive circuit 24 and the deflection coil DF, and at the same time, FIG.
Donut-shaped hatched area in the region B ₁ only to allow passage of the electron beam, the feed to the blanking drive circuit 22 a shutter signal via conductors L _11, electronic shutter SH
To a predetermined potential for blanking. By this operation, the electron beam reaches only the concentric triangular region of the triangle αβγ in FIG.

Similarly, as the next third scan,
A scanning signal having a sawtooth waveform corresponding to a slower scanning speed C ₂ (FIG. 4) is supplied to the scanning coil drive circuit 24 and the deflecting coil DF, and at the same time, the electron beam is emitted only in the donut-shaped hatched area B _{2 in} FIG. to allow the passage, the feed to the blanking drive circuit 22 a shutter signal via conductors L _11,
A predetermined potential for blanking is applied to the electronic shutter SH. By this operation, the electron beam reaches only the concentric cross mark area of the triangle αβγ in FIG.

Hereinafter, by the fourth, fifth, and sixth similar scans, concentric square marks, x marks, and double circle marks of the triangle αβγ are sequentially drawn, and finally, the triangle αβγ
Is completed for all the regions.

From the above description, it is possible to understand the functions required of the scan synchronization processing section 20 which plays a major role in the present invention, and to form the input signals necessary for the drawing processing and the input signals necessary for the drawing processing by arithmetic processing. Output signal to be specified. And
It is also necessary to provide a storage device (usually a dynamic RAM) for temporarily storing the input signal and extracting it when needed.

As the input signal, first, the information of the original drawing necessary for drawing, that is, in the case of FIG. 3, the input signal for the parameter specifying the coordinates of each vertex of the triangle αβγ and the three straight lines connecting them (in FIG. L input from _1), the coordinates of the next border delimiting the gradient region, i.e. circle S ₀ in FIG. _2b,
S _1, S _2, (entered in FIG. 1 from the conductor L ₂₎ an input signal for mapping the coordinates of ..., and the input signal for determining the timing of the scanning signal (input from the lead L ₃ in Fig. 1 Is necessary). In addition, in order to measure the distribution characteristics of the irradiation current (the current density distribution diagram in FIG. 2A), a lead L ₁₃ is supplied from an ammeter 26 provided in the scanning electron microscope 30.
There is an input signal of a current value input through the.

[0024] As an output signal, it is the excitation signal for the blanking signal and deflection coils DF for electronic shutter SH respectively output via leads L ₁₁ and L _12, which has already been described in detail above. In addition, the measured irradiation current is AD-converted and then stored by specifying an address corresponding to the pixel, and an output signal is output to send the stored value to the image processing apparatus 10. Note that conductors L _1, L ₂ and L
₃ is capable of bidirectional transmission as described later.

An output signal supplied from the graphic processing unit 9 corresponding to the original drawing to be drawn, that is, the original drawing is decomposed into a number of graphic elements, and a command (for example, a straight line, a circle, an arc, Commands for triangles, squares, rectangles, etc.) and the coordinates of the starting point and associated parameters (for example, the length of a straight line,
Radius of the circle, the length of the side of a polygon, etc.) is introduced from the conductor L ₁ to the original-data generation unit 42 of the scanning synchronization processing unit 20. The original drawing data generation section 42 sets the entire scanning area as one frame based on the generated original drawing data and creates image information for this frame. That is, binary information (for example, a digital value that becomes 1 when the electron beam is irradiated and a digital value that becomes 0 when the electron beam is not irradiated) for each pixel in the frame is serially transmitted in accordance with the scanning direction in the x direction, for example. create. The created information is sequentially introduced and stored in the next original drawing storage unit 44.

Next, the gradation information, that is, the boundary line S in FIG.
_The gradation boundary graphic composed of _0, S1 _, S2 _, ... (The preparation of this graphic itself will be described in the next step) is decomposed into image elements in the same procedure as the original drawing, and attached with an image element designation command. and the parameter from the graphic processor main body 9 via conductor L ₂ is introduced to the gradation graphic data generating unit 43 of the scanning synchronization processing unit 20. Then, similarly, the image information is converted into image information for one frame, introduced into the gradation figure storage unit 45, and stored.

A gradation boundary graphic is created in the following procedure.
Before drawing, the intensity of the electron beam reaching the entire scanning area is measured by a scanning electron microscope used in advance. The intensity of this electron beam is converted into a current value from the ammeter 26 by the scan synchronization processing unit 2.
Is supplied to an analog-to-digital converter 50 of 0, where via conductors L ₄ in the digital values introduced into graphics processing body 9, to create a current density distribution information corresponding to Figure 2a.
This distribution information is returned to the scan synchronization processing unit 20 again, and stored in the current density distribution storage unit 49 for one frame. If necessary, the stored current density distribution information is taken out and sent to the figure processing body 9, where the number of gradations, the gradation width, etc. are selected according to the electron beam resist or the material to be drawn, and the input unit 2 and the sequence control program stored in the control storage (for example, the ROM or the external storage 6) of the graphic processing main body 9, the boundary lines S0 _, S1 _, Create S2 _, ...

The timing circuit 47 of the scan synchronization processing section 20
In either of the gradation signal is the tone of the x-direction scanning start trigger pulses and what stage is introduced via a line L ₃ from the graphic processing body 9. In this timing circuit 47, the scanning speed (C _0, C _1, C _2, ...
The scanning time in the x direction determined by any of the above is calculated, and during this period, a predetermined digital value, for example, “1” is continuously output. At this time, the end point of the x-direction scanning is calculated, and an x-direction scanning end pulse is formed. The x-direction scanning end pulse is used as a start trigger pulse for the x-direction scanning of the next adjacent scanning line, and becomes a signal corresponding to one step of scanning in the y-direction. The predetermined digital value is supplied to an x-direction scanning signal generator 48 at the same time as being supplied to a blanking output circuit 46 described below. Here, during the duration of the predetermined digital value, a current flowing through a resistor from a constant voltage generated from a digital-to-analog converter (not shown) is time-integrated and converted into a sawtooth waveform voltage. Conveniently, the integration uses a well-known analog current-to-voltage conversion circuit (not shown). The scanning speed is changed by changing the constant voltage value from the digital / analog converter.

Whether or not the scanning electron beam is used for drawing is determined by the blanking output signal of the blanking output circuit 46. As described above, when the blanking output signal is “H”, the electronic shutter SH is turned on to make the electron beam non-transparent, and when the blanking output signal is “L”, the electronic shutter SH is turned off to make the electron beam transparent. (The relationship may be reversed). Blanking output circuit 46
Determines whether the blanking output signal is “H” or “L” for each pixel during the scanning period, and supplies it to the drive circuit 22 of the electronic shutter SH. The blanking output signal for the above determination is based on the two-dimensional address of the pixel to be scanned formed by the timing circuit 47 (determined by the scanning time in the x direction and the trigger pulse in the y direction scanning). And the stored value in the corresponding pixel of the gradation figure storage unit 45.

An original drawing data generator 42 and a gradation figure generator 43 used in the scan synchronization processing section 20 according to the present invention.
Can be constituted by a commercially available integrated circuit for graphic controller, for example, μPD72123 (NEC). Further, each of the original figure storage unit 44, the gradation figure storage unit 45, and the current density distribution storage unit 49 can be constituted by one or more readable large-capacity storage units, for example, a dynamic RAM.

In the above description, an address generation circuit or a monitoring circuit, a clock circuit necessary for various timings,
Description of the memory control circuit and the like is omitted at all. This is because these descriptions may complicate and confuse the contents of the main part of the present invention. Since the functions on the circuit are described in sufficient detail, those skilled in the art can easily assume the configuration of the circuit.

The present invention can be variously modified or modified based on the description. For example, the two graphic generators 42 and 43 of FIG. 5 are formed by only one graphic controller, and the original drawing data and the gradation graphic data are separately processed with the aid of the control program and stored in the corresponding storage unit 44 or 45. You can also. In this case, the conductors L1 _, L
₂ can be constituted by one bus line.

In any case, it goes without saying that any method and apparatus having the structure defined in the claims fall within the scope of the present invention.

[0034]

As described above, the electron beam lithography method according to the present invention and the electron beam lithography system for executing the method comprise a scanning electron microscope which can be obtained at low cost or a handheld or electron microscope. By using an image processing apparatus and adding no simple electronic circuit device according to the present invention to the scanning electron microscope without any modification, electron beam drawing of a relatively complicated figure can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall arrangement of an electron beam writing system according to the present invention.

FIGS. 2A and 2B are a graph (a) showing a map of measured irradiation current densities and a drawing (b) showing an area corresponding to each gradation of the irradiation current density.

FIG. 3 is a drawing showing regions at different scanning speeds from the original drawing.

FIG. 4 is a graph showing various horizontal scanning speeds selectively used according to the gradient (the horizontal axis is the horizontal length corresponding to the entire screen).

FIG. 5 is a detailed block diagram of a scan synchronization processing unit used in the electron beam drawing system according to the present invention.

[Explanation of symbols]

Reference Signs List 2 input unit 4 display device 6 external storage device 9 graphic processing unit 10 graphic processing device 20 scan synchronization processing unit 30 scanning electron microscope 22 electronic shutter drive unit 24 deflection coil drive unit 26 ammeter SP drawing object SH electronic shutter DF deflection coil _{L 1, L 2, L 3} , L 4, L 11, L 12, L 13, wire S _0, S _1, S ₂ tone boundaries 42,43 graphics generator 44,45,49 storage 46 Burankigun output circuit 47 timing circuit 48 scanning signal generator 50 analog / digital converter

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-107533 (JP, A) JP-A-62-137824 (JP, A) JP-A-59-181615 (JP, A) JP-A-58-1983 56418 (JP, A) JP-A-5-29203 (JP, A) JP-A-3-290767 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/027

Claims (6)

(57) [Claims] 1. A graphic data is inputted, and a graphic is required for an individual graphic.
The type and location of the graphic element that
Frame figure for electron beam scanning consisting of markers and required parameters
Graphic processing device (10) for outputting data, drawing object
(SP) is irradiated with an electron beam according to a desired drawing figure and drawn.
Scanning electron microscope (30) and graphic processing device
Based on the scanning frame graphic data supplied from (10)
In order to form a desired drawing figure, the scanning electron microscope
Activate the electronic shutter (SH) of the mirror (30)
King output signal and deflection scanning signal to deflection coil (DF)
Electron beam drawing using a scan synchronization processing unit (20) that outputs
In the drawing method, when scanning with an initial electron beam of constant intensity,
Predict the electron current density reaching each individual scan area of
A plurality of gradations (A_0,A_1,A _Two・ ・
・) And the boundary of each individual gradation area in the scanning frame
Line (S_0,S_1,S_Two...), and a graphic to be processed in the graphic processing device (10) is input.
An original drawing and the gradation figure, wherein the gradation (A_0,A_1,A_Two…)) Almost the same current density
The electron beam scanning speed (C_0,
C_1,C_Two...) for each gradation (A_0,A_1,A_Two...)
The electron beam scanning position is set to the desired gradation range in the frame and the desired drawing.
Only when it is in the figure, the electron
(SH), and the power corresponding to the gradation
The deflection coil (DF) is scanned at the slave line scanning speed, and the above electron beam scanning is performed for all gradations (A_0,A_1,A_Two...)
An electron beam drawing method, wherein the method is performed for: 2. Predicted electron current density is obtained beforehand from a measurement signal of an ammeter (26) before drawing, and gradation is determined according to the degree of electron beam interaction between an electron beam resist or a drawing object (SP). The electron beam drawing method according to claim 1, wherein the electron beam drawing method is determined. 3. The predicted electron flow density is empirically determined, and the gradation is determined by an electron beam resist or a drawing object (SP).
The electron beam drawing method according to claim 1, wherein the electron beam drawing method is determined according to the degree of the electron beam interaction. 4. An electron beam lithography system for executing the electron beam lithography method according to any one of claims 1 to 3, wherein the scan synchronization processing unit (20) is provided with an original drawing data supplied from a graphic processing device (10). An original data generator (42) for creating an original for one frame, and an original storage (4)
4), a gradation graphic data generator (43) for creating a gradation graphic for one frame from the gradation graphic data supplied from the graphic processing device (10), and a subsequent gradation graphic storage (45) A timing circuit (4) for generating a scanning speed corresponding to each gradation based on an input signal of a gradation and a scanning start and a scanning end signal supplied from the graphic processing device (10).
7), following the timing circuit (47), this circuit (4
7) A scanning signal generator (48) for generating a scanning drive signal for driving the deflection coil (DF) from the output signal, an original drawing storage unit (44), a gradation figure storage unit (45), and a timing circuit (47). And from these output signals,
An electronic beam drawing system, comprising: a blanking output circuit (46) for outputting a blanking output signal to an electronic shutter (SH) in accordance with a corresponding gradation at each scanning position in a frame. 5. An electron beam lithography system for executing the electron beam lithography method according to any one of claims 1 to 3, wherein the scan synchronization processing section (20) uses original drawing data supplied from a graphic processing device (10). A figure generator that creates an original figure for one frame and creates a gradation figure for one frame from the gradation figure data, followed by an original figure storage unit (44) and a gradation figure storage unit (45), A timing circuit (47) and a timing circuit (47) for generating a scanning speed corresponding to each gradation based on the input signal of the gradation and the scanning start and end signals supplied from the device (10). A scanning signal generator (48) for generating a scanning drive signal for driving the deflection coil (DF) from an output signal of the circuit (47),
And an original shutter (44), a gradation figure storage (45), and a timing circuit (47), and from these output signals, an electronic shutter according to the corresponding gradation at each scanning position in the frame. An electron beam writing system characterized in that a blanking output circuit (46) for outputting a blanking output signal is provided in (SH). 6. An analog-to-digital converter (50) for converting a current value from an ammeter (26) of a scanning electron microscope (30) into a digital value in the scanning synchronization processing section (20).
6. An electron beam writing system according to claim 4, further comprising a storage unit (49) for storing the current value for each pixel in the frame.