JP3285645B2 - Charged beam drawing 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 charged beam drawing method for forming a semiconductor integrated circuit and other fine element patterns on a substrate such as a semiconductor wafer or a pattern transfer mask using a charged beam.

[0002]

2. Description of the Related Art Hitherto, to form a pattern on a substrate such as a semiconductor wafer or a mask, a method of transferring a pattern from light or a method of drawing a desired pattern using a charged beam have been used. In particular, there is no means for forming a pattern other than using a charged beam for forming a pattern that cannot be resolved by light. However, when a charged beam is used, it takes an extremely long time to form a pattern, and is not suitable for manufacturing a highly integrated semiconductor device. The character projection method has been devised to shorten the pattern formation time. In the character projection method, since the figure of the minimum unit of the repetitive pattern is characterized and drawn as one shot, the figure of the minimum unit is made as large as possible and formed as a character in the aperture to form one shot, so that the total number of shots is reduced. Can be reduced.

However, when the shape of the outer frame of the minimum unit is not rectangular, the occupied area is larger than in the case of the rectangle, and when the size of the character aperture of the apparatus exceeds the limit, the figure is not divided into two or more figures. There was a problem that it could not be formed on the aperture.

Further, when the shape of the figure as the minimum unit is a donut shape, there is a problem that the figure cannot be formed on the aperture.

In the character projection system, a character figure shape to be drawn is selected by a shaping deflection system, and a beam shape is reduced by a short and short system. There is a problem that the position to be drawn on the image is shifted from a desired position. Conventionally, as a method for solving this, the beam is deflected to the desired drawing position in the drawing data by the objective system by swinging the beam with the shaping deflection system, selecting the character, and then swinging the beam back using the back deflection system. I was However, if this method is used, it is necessary to attach a control circuit, a deflection amplifier, and a deflector for a return deflection system to the drawing apparatus, which complicates the system. There is a problem that the number of items increases and the accuracy of the apparatus is deteriorated or the adjustment time is increased. Further, when there are many types of character shapes formed on the aperture, the amount of deflection of the return movement becomes large, the optical deflection aberration due to the return deflection becomes large, and the desired resolution cannot be obtained, and the shape of the character graphic shape that can be formed on the aperture is not obtained. There is a problem that the number of types is reduced, and the effect of improving the throughput in the character projection system cannot be sufficiently obtained.

The size of the shaping deflection area on the aperture when selecting the figure shape of the character is determined by the deflection aberration of the optical system. However, as the deflection amount increases, the deflection aberration increases and the beam resolution deteriorates. There is a problem that the deflection area cannot be enlarged, and the number of types of character figures that can be formed in the deflection area on the aperture is reduced, so that the effect of improving the throughput of the character projection method cannot be sufficiently obtained.

[0007]

As described above, in the conventional charged beam drawing method using the character projection system, it may be impossible to characterize the shape of the minimum unit as it is, and the figure of the minimum unit of repetition may occur. Cannot be drawn in one shot, and characters or variable shaped beams of two or more shots must be used together, and there is a problem that the effect of improving the throughput by the character projection method cannot be sufficiently obtained. Also, since one minimum unit figure requires a plurality of character shapes, an area on the aperture where a finite character shape can be formed is used more than necessary, and another shape which is the minimum unit of repetition is placed on the aperture. There is a problem that the formation cannot be performed and the throughput cannot be sufficiently improved.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances. It is an object of the present invention to form a single character on an aperture in a charged beam drawing method using a character projection method. By changing the shape of the outer frame of the figure, which is the minimum unit of repetition, which was impossible to form, so that it can be formed as a single character on the aperture, drawing that can fully exploit the effect of improving the throughput of the character projection method It is to provide a method.

The present invention has been made in view of the above circumstances, and has as its object to increase the number of types of character figures that can be formed on an aperture to improve throughput.

[0010]

The gist of the present invention is to provide a charged beam drawing apparatus for irradiating a charged beam on a sample and writing a desired pattern on the sample. The shape of the figure as a unit is formed in the shaping aperture of the electron optical system,
In the area of the repetitive pattern, a character projection method for drawing using the aperture is provided, and when the minimum unit is a rectangular outer frame, the aperture is formed in the aperture as it is, and a desired pattern is drawn. If the shape of the outer frame of the minimum unit graphic is not rectangular, the minimum unit graphic is changed so that the minimum unit graphic of the repetitive pattern becomes a rectangle, and the minimum unit graphic is formed in the aperture. In other words, the pattern processing is performed using pattern data designed to process the excess or deficiency pattern that occurs when the pattern is drawn with a pattern adjacent to the repeated pattern.

[0011]

According to the present invention, it is possible to form a single character on a character aperture by changing the minimum unit graphic into a rectangle when the shape of at least the minimum unit of the repetitive pattern is other than a rectangle. As a result, the minimum unit shape is indiscriminately divided into two or more character shapes, thereby avoiding unnecessarily occupying the character shape formable area on the aperture and improving the throughput by the character projection method. The effect can be fully obtained. In addition, by changing the shape of the figure of the minimum unit of repetition that cannot be physically formed on the aperture, such as a donut-shaped pattern, to a shape that can be formed on the aperture, it is necessary to draw by the conventional variable shaping beam. The drawn figure can be drawn by character projection, and the throughput can be improved.

The reason why the shape of the figure of the minimum unit of repetition can be appropriately changed as described above will be described with reference to FIGS. Normally, as shown in FIG. 1, the repeating pattern 1 can be represented as a group of parallelograms having a translation period. At this time, as shown in FIG. 2B, the basic vectors representing the parallelogram 2 which is the minimum unit are a and b. As shown in FIG. 2A, when a · b ≠ 0 and a> b, one side is (| b | sin θ
+ | A |)). Assuming that the maximum character size on the sample surface of the apparatus is L, L <
In the case of (| b | sin θ + | a |), the parallelogram of the minimum unit cannot be directly used as the character shape.
However, as shown in FIG.
(A · b ′ = 0, a> b), a ≦ L
Then, it is possible to form the basic unit figure as one character shape on the aperture and draw it by the character projection method. At this time, the excess and deficiency due to the change in the shape of the basic unit figure are generated at both ends of the repetition pattern 3, and these are circuit patterns which can process the excess and deficiency in blocks adjacent to the repetition pattern as shown in FIG. 4 is set in the design stage.

Further, when the repeating basic unit figure 5 as shown in FIG. 4 is a donut-shaped pattern, it is impossible to physically form it in an aperture shape even if the size itself is smaller than L. The hatched portion 6 is a portion that blocks electrons, and the donut-shaped blank portion 7 is a portion that transmits electrons. However, as shown in FIG. 5, by changing the figure 8, which is a basic unit, it is possible to form a physical aperture. At that time, 50 in FIG.
There is a portion which cannot be drawn as it is using the character shape in this portion, but this portion uses a variable shaping beam or a rectangular shaped aperture image 9 of another rectangular shape in FIG.
Can be drawn by projecting as follows.

Further, according to the present invention, when a desired character figure shape is selected by the shaping / deflection system, even if the beam is deflected to a desired drawing position by the objective system, the beam deviates from the actual drawing position. The problem can be solved without attaching the return deflection system, and it is possible to prevent an increase in error factors, an increase in adjustment items, and a decrease in resolution due to the addition of the return deflection system. Therefore, the accuracy of the drawing apparatus and the throughput operation rate can be improved. FIGS. 12 to 13 show the reason why drawing can be performed at a desired drawing position without using the swingback deflection system.
This will be described with reference to FIG.

First, FIG. 12 is a schematic view of an electron optical system using a conventional swing-back deflection system. Selecting a character shape in the shaping deflection system leaves the beam polarized. Therefore, even if this is deflected to a desired drawing position by the objective deflection system as it is, it is deflected by the shaping deflection system, so that the actual drawing position is shifted from the desired position as shown in FIG. . Therefore, as shown in FIG. 12B, the beam is deflected to the desired drawing position by the objective deflecting system by deflecting the beam by the return deflector 91 by the amount deflected by the shaping / deflecting system. Will be drawn. In the present invention, the role of the swing-back deflection system is assigned to the objective deflection system, and a desired drawing position in drawing data input to the drawing device is determined by selecting a character shape in the forming deflection system in advance. Or by adding a deflection amount corresponding to the deviation of the drawing position from the desired drawing position to the deflection amount in the objective deflection system by a dedicated circuit for changing the drawing position.
As shown in FIG. 13, it is possible to draw at a desired drawing position without using the swingback deflection system.

Further, according to the present invention, the limitation on the scanning area of the beam by the shaping deflection system on the aperture capable of forming the character graphic shape due to the reduction in the resolution of the beam is relaxed, so that the aperture in the beam scanning area is reduced. It is possible to improve the throughput by increasing the types of character graphic shapes that can be formed.

The reason will be described with reference to FIGS. 15 shows the relationship between the beam deflection and the shaping deflection area on the aperture calculated for the shaping deflection system of the electron optical system shown in FIG. As shown in FIG. 14, the resolution decreases as the deflection area increases. For example, in order to obtain a minimum line width of 0.15 μm, a beam resolution of 0.03 μm is required. In this case, the shaping deflection area is 1 mm □. In order to obtain a minimum line width of 0.25 μm, a beam resolution of 0.05 μm is required.
m is required, and in this case, the molding deflection area is 2 mm □
Becomes Therefore, the character figure shape has a minimum dimension of 0.15
In the case of including a figure of μm or less, the aperture 92 in FIG.
It is sufficient to arrange the character graphic shape in the area of the upper area A, and to arrange the graphic having the minimum dimension of 0.25 μm or less in the area on the aperture of the area B shown in FIG. Further, a character figure shape composed of a figure having a large size can be arranged in the area C in FIG. 15 from the relationship between the resolution required for the minimum line width and the deflection area.

In a charged beam, since there is a Coulomb interaction between charged particles in the beam, a repulsive force is generated between the charged particles, causing beam blur and degrading the resolution. Therefore, even in a character shape composed of a figure having the same minimum line width, the blur amount of the beam varies depending on the aperture ratio of the aperture. For example, FIG.
In (a) and (b), the aperture ratio of the aperture is 50% and 20%.
%, The beam blur due to Coulomb interaction is 0.05 μm and 0.02 μm, respectively (acceleration voltage 50 k
V, convergent half-angle of 5 mrad, current density of 10 A / cm 2, character beam size of 5 μm square, and length of the objective system from the second shaping aperture to the sample surface of 270 mm).
The contribution of the shaping deflection system to the beam resolution is determined by the shaping deflection aberration and the area of the character-shaped opening in the second aperture, which causes beam blur due to Coulomb interaction (FIG. 16).
By arranging the character shape of (a) in the area A near the center of the aperture forming deflection area as shown in FIG. 17, the total beam resolution is 0.058 μm, and the character shape of FIG. By arranging at B, the total beam resolution becomes 0.054 μm. Figure 1
6 (A) is arranged in the area B of FIG. 17 and FIG.
7, the total beam resolution becomes 0.07 μm and 0.036 μm, respectively, and the resolution in drawing the shape of FIG. FIG.
By arranging the character shape as described above, it is possible to suppress the degradation of the resolution.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of the present invention will be described with reference to FIG. 7 which shows an electron beam lithography apparatus used in a method of an embodiment of the present invention. In the figure, 10 is a sample chamber, 11 is a target (sample), 12 is a sample stage (stage), 20 is an electron optical system barrel, 21 is an electron gun, 22a to 22e are various lens systems, and 23 to 26 are various deflection systems. , 27a are blanking plates, 27b is a first formed aperture mask, and 27c is a second formed aperture mask. A character pattern as described later is also formed on the second formed aperture mask 27c, and drawing by a character projection method is possible. In the apparatus of the present embodiment, the reduction ratio is 1/40, and the size of the character shape on the aperture may be formed to be 40 times the size on the sample surface.
That is, a character having a size of 5 μm square on the sample surface has a size of 200 μm square on the aperture.

In the figure, reference numeral 31 denotes a sample stage drive circuit unit;
Is a laser length gauge, 33 is a deflection control circuit, 34 is a blanking control circuit, 34 is a variable shaped beam and character beam control circuit, 36 is a buffer memory and control circuit, 37 is a control computer, 38 is data conversion and The computer for calculating the optimum irradiation time, 39 indicates a CAD system.

The electron beam 90 emitted from the electron gun 21
Is ON-OFF controlled by the blanking deflector 23. In this apparatus, by adjusting the irradiation time at this time, the irradiation amount can be changed according to the shot irradiation position. The beam having passed through the blanking plate 27a is deflected and scanned on the target 11 by the beam shaping deflector 24, the first shaping aperture mask 27b, and the second shaping aperture mask 27c. It is to be drawn in a pattern.

Next, an electron beam drawing method using the above apparatus, particularly a character projection method and a drawing method using a normal variable shaped beam will be described. FIG. 8A shows an aperture mask for a variable shaped beam formed on the aperture mask 27c, a rectangular aperture formed on the aperture mask 27b, and FIG. 8B shows a character aperture mask formed on the mask 27c. The shape shown in FIG. 8B is divided into 19 shots 92 as shown in FIG. 9 using a normal variable shaped beam. Therefore, by using the character aperture as shown in FIG. 8B, a speedup of 19 times can be realized. The maximum character beam size of the apparatus used in this embodiment is 5 μm square on the sample surface, and the size on the aperture is 200 μm square. The number of characters that can be placed in the shaping deflection area on the aperture is 36.

Hereinafter, embodiments of the present invention will be described. In this embodiment, a repetition pattern 2 as shown in FIG.
Shall be drawn. The minimum unit of the repetition pattern has the shape shown in FIG. The outer shape of the shape is a parallelogram, and the angle θ shown in FIG.
is not. Since this shape is larger than the maximum character beam size of the device, it cannot be used as it is. Therefore, as shown in FIG. 10 (b), the shape of the figure serving as the minimum unit 3 is changed. The excess or deficiency 94 of the pattern shown in FIG. 10C caused by the change of the minimum unit is designed in consideration of the pattern of the peripheral circuit in advance. The size of the changed shape is 5 μm on the sample surface
Since it becomes smaller than the maximum character beam size of the device in □, it can be defined as a character shape. By forming this character shape on the aperture, drawing by the character projection method becomes possible.

Next, another embodiment according to the present invention will be described. In this embodiment, a repetitive pattern 3 as shown in FIG. 11A is drawn. As shown in FIG. 11A, the minimum unit figure of the repetitive pattern has a size on the sample surface of 4 μm □ smaller than the maximum character size, but cannot be formed on the forming aperture as it is.
Therefore, when the minimum unit figure is changed as shown in FIG. 11B, it becomes physically possible to form the figure on the forming aperture. When drawing is performed using the aperture of the shape, FIG.
In the portion shown in FIG. 11B, an area 95 that cannot be drawn with the aperture having the shape is generated. Therefore, the ordinary variable shaped beam or the aperture having the shape is illuminated by the first shaped aperture as shown in FIG. 11C. Writing is performed using the formed beam 96. Further, as in the above-described embodiment, it is also possible to define the peripheral pattern in consideration of the pattern around the repetitive pattern in advance and draw using a variable shaped beam.

The change of the minimum unit in the above-described embodiment may be performed in advance at the time of data conversion for converting CAD data into data for a drawing apparatus. It is also possible to carry out the present invention with appropriate modifications.

Next, still another embodiment according to the present invention will be described. In this embodiment, first, a character shape 97 is arranged on an aperture for forming a character graphic shape as shown in FIG. In the apparatus of the present embodiment, the beam scan area (shaping deflection area) of the shaping deflection system on the aperture is 2 m.
m □. An opening for a variable shaped beam as shown in FIG. 9A may be arranged at the center. FIG. 19 shows the drawing position change amount 101 in the objective system with respect to the arrangement position coordinates 100 on the aperture of each character shape in FIG. The arrangement position of the character shape on the aperture is given by a code,
FIG. 20 shows the relationship between the code 102 and the coordinates 103. FIG. 21 shows the configuration of the drawing data used in this embodiment. FIG. 26 is a schematic diagram of the drawing control circuit used in this embodiment. The data is composed of a figure code, irradiation time, figure position, and figure size in the case of a figure drawn by the variable shaped beam, and a figure drawn by the character method is formed of a character shape code, drawing position, and irradiation time. In the case of the variable shaping beam system of the drawing data, the shaping deflection control circuit 57 is used based on the figure code and the figure size of the drawing data.
The shaping deflection amount is calculated, a deflection voltage corresponding to the deflection amount is applied to the shaping deflector 63, and the beam is shaped into a desired shape and size. In the case of the character projection system, the shaping deflection amount is calculated by the shaping deflection control circuit 57 from the character graphic code, and a deflection voltage corresponding to the deflection amount is applied to the shaping deflector 63. Then, the drawing position of the drawing data is calculated by the data generator 64, the objective deflection amount is calculated by the objective deflection control circuit 65, and the deflection voltage according to the deflection amount is applied to the objective deflectors 61 and 62, and the beam is deflected to a desired position. Is done. In the apparatus used in this embodiment, the objective deflection system has two main and
When the drawing position is calculated, first, the main deflector 61 positions the sub-deflection area, and then the sub-deflector 62 determines the position of the drawing figure.
The main deflection area is 600 μm square, and the sub deflection area is 30 μm square, and it is possible to perform the swing back by the main deflection. As shown in FIG. 21, the drawing data is configured such that the position of the sub-field 104, which is the sub-deflection area, is defined first, and the graphic data is defined therein. The subfield position means a subfield origin position coordinate 202 with respect to a frame 201 which is a basic unit of continuous movement drawing in the chip 200 as shown in FIG. The deviation of the drawing position caused by deflecting the beam to select the character shape by the shaping deflection system is performed by changing the main deflection position, that is, the coordinates of the origin of the subfield. FIG. 23 shows drawing data in which the subfield origin position has been changed. The CAD data is converted into drawing data by a data conversion computer. In this case, when a character shape is used, the character shape arranged in a specific subfield is one.
The type is limited to the type, and the subfield position change amount is obtained from the character shape code. At this time, the coordinates of the origin position of the subfield including the data drawn by the variable shaped beam are not changed. By using this drawing data, the character figure shape can be drawn at a desired drawing position without using the back deflection system. The configuration of the drawing control circuit shown in FIG. 26 used at this time is exactly the same as that of the conventional drawing apparatus.

The present invention can be carried out as follows. FIG. 27 shows the configuration of the drawing control circuit used at this time. In this case, the drawing data uses the uncorrected original position of the subfield.
However, it is assumed that only one type of character shape can exist in one subfield, and the drawing data to be drawn by the variable shaped beam is created by the data conversion computer so that the drawing data is defined to exist in another subfield. I do. In this case, each subfield position may be defined by origin coordinates, or may be expressed by an identification number or an identification symbol. In this embodiment, the origin coordinates of the subfield are defined by the identification numbers as shown in FIG. After obtaining the main deflection amount change amount in the objective system for the arrangement position coordinates of each character shape on the aperture, the character shape code 300 and the main deflection position change amount 301 are stored in the memory of the main deflection operation circuit 75 as shown in FIG. Is stored in association with. The main deflection position change amount corresponds to the drawing position change amount.
The data generator 84 calculates the coordinates of the subfield from the subfield identification number as x = Lx.IDxy = Ly.IDy. Where (x, y) is the subfield coordinates, (Lx, Ly)
Is the size of the subfield in the x and y directions, (I
Dx, IDy) represents a subfield identification number.
Next, it is determined from the shape code of the first figure defined in the subfield whether a character shape is included in the subfield. If there is no character shape, the main deflection position data is used as it is in the main deflection calculation. The main deflection calculation circuit 75 obtains the main deflection amount from the coordinates of the subfield, converts the digital data into analog data, and applies a deflection voltage required for deflection to the main deflector 81 by the main deflection amplifier 78. The calculation circuit calculates the amount of deflection from the figure position,
The digital / analog conversion is performed, and the corresponding deflection voltage is applied to the sub deflector 82 from the sub deflection amplifier 79. When the character shape is included in the subfield, the character code is sent to the main deflection calculation circuit 75 together with the main deflection position data, and the main deflection calculation circuit 75 refers to the character code and stores the character shape code stored in the memory. The main deflection change amount (Wx, Wy) is obtained by referring to the correspondence relationship between the main deflection position change amount and the main deflection position, and is added to the main deflection amount (Xm, Ym) calculated from the main deflection position data as in the following equation. Xm = Xm + Wx + (deflection distortion correction term) Ym = Ym + Wy + (deflection distortion correction term) A digital / analog conversion is newly performed as a main deflection amount, and a deflection voltage corresponding thereto is supplied from the main deflection amplifier 78 to the main deflector 81.
Applied to. At this time, if necessary, a deflection distortion correction term can be added as in the above equation. (Wx, Wy
) Is a unique value of each character code. The deflection amount corresponding to the figure position is calculated by the sub deflection calculation circuit 76 from the drawing position of the character shape, and the corresponding deflection voltage is applied to the sub deflector 82 from the sub deflection amplifier 79. As described above, it is possible to draw a desired character shape at a desired drawing position without using the swingback deflection system.

In this embodiment, the drawing position is changed by the objective main deflection in the objective two-stage deflection system. However, in any objective deflection system, the deflectable area is used for correcting the position of the deflection amount on the forming aperture. This embodiment can be modified and used as long as it is acceptable.

Next, still another embodiment according to the present invention will be described. FIG. 14 shows the shape of the shaping deflection area and the beam resolution on the aperture used in this embodiment. The area required to obtain the minimum dimension of 0.15 μm is the area A shown in FIG. 17, and four types of character shapes can be formed.
There are twelve regions B in FIG. 17 necessary to obtain the minimum dimension of 0.25 μm. The data conversion computer 501 extracts a block having a large number of repetitions from the design data 500 and defines it as a character shape to create drawing data. At this time, a character aperture for forming a character shape as shown in FIG. Data 511 is created similarly. The character aperture data includes layout information 512 on how the character shapes are arranged, and is used when creating the character aperture. Therefore, at the time of data conversion, the minimum size is calculated from the extracted graphic data of the contents of the character shape, and as shown in FIG. In this case, if there are a plurality of character shapes including figures having the same minimum dimensions, FIG.
(B) Calculate the area of each opening and arrange the one with the larger opening inside. FIG. 29C shows an image of a layout in which character shapes are actually arranged. In this way, by drawing using the character aperture in which the character shape is arranged in the molding deflection area in consideration of the minimum size and the opening area, it is possible to draw with the minimum necessary resolution for each character shape. Can,
The types of character shapes that can be formed on the aperture also increase.

When a character shape is used for correction drawing in the case of using a correction drawing method using a blur beam as proximity effect correction, the character shape does not require a high resolution, as shown in FIG. What is necessary is just to arrange | position at the end part of a shaping | deflection area | region. A region for a variable shaped beam for correction drawing may be formed at an end portion.

The present invention is not limited to the above embodiments. In the embodiment, the electron beam drawing apparatus capable of drawing by the character projection method is used. However, an ion beam drawing apparatus capable of drawing by the character projection method may be used instead. In addition, various, without departing from the gist of the present invention,
The present invention can be modified and implemented as appropriate.

[0032]

As described above in detail, according to the present invention, it is possible to define a character smaller than the maximum character size of the apparatus by changing the way of taking the minimum unit figure constituting the area of the repetitive pattern. Become. Also, by changing the way of taking the minimum position figure constituting the region of the repetitive pattern, a shape that cannot be physically formed on the forming aperture can be defined as a shape that can be formed. By using the beam of the character shape defined as described above, it is possible to draw at high speed.

As described in detail above, according to the present invention, in the drawing apparatus of the character projection system, the reversing deflection system is formed by reversing the beam deflection caused by the shaping deflection simultaneously with the positioning of the drawing position by the objective deflection system. It is possible to draw a character shape at a desired drawing position without using it. Therefore, since it is not necessary to add the swingback deflection function, it is possible to reduce the number of error factors and adjustment items, and realize a high-precision and high-throughput drawing method and drawing apparatus.

As described in further detail above, it is necessary to draw each character shape by arranging the character shape formed on the shaped deflection field in the aperture according to the minimum size of the figure included therein and the area of the opening. Drawing can be performed at a resolution, the number of types of characters that can be formed on the aperture can be increased, and throughput can be improved.

[Brief description of the drawings]

FIG. 1 is a general configuration diagram of a repeating pattern.

FIG. 2 is an explanatory diagram of changing a minimum unit of repetition.

FIG. 3 shows an extra pattern generated by changing a minimum unit of repetition.

FIG. 4 is a pattern showing a minimum repeating unit figure that cannot be physically formed on an aperture.

FIG. 5 is an explanatory diagram of changing a minimum unit of repetition.

FIG. 6 is a view for explaining a method of drawing an insufficient pattern caused by changing a minimum unit of repetition.

FIG. 7 is a schematic configuration diagram showing an electron beam drawing apparatus used in an embodiment of the present invention.

FIG. 8 is a plan view showing an aperture shape.

FIG. 9 is a diagram showing the number of shots when a figure that can be drawn in one shot by the character projection method is drawn by a variable shaped beam.

FIG. 10 is a diagram for explaining Example 1 of the present invention.

FIG. 11 is a view for explaining Example 1 of the present invention.

FIG. 12 is a schematic diagram for explaining a shift of a drawing position and a result of the swingback deflection when the swingback deflection is not performed.

FIG. 13 is a view for explaining a method of correcting a deviation of a writing position without using a return deflection.

FIG. 14 is a diagram showing a relationship between a beam resolution and a shaping deflection area size.

FIG. 15 is a diagram showing regions having different resolutions on a shaping deflection region on an aperture.

FIG. 16 is a view for explaining character shapes having different opening areas.

17 is a view for explaining a method of arranging the character shape in FIG. 16 on an aperture.

FIG. 18 is a diagram showing an aperture in which character shapes used in the second embodiment of the present invention are arranged.

FIG. 19 is a diagram illustrating a relationship between a character position on an aperture and a swingback amount.

FIG. 20 is a diagram showing a character position and a character code on an aperture.

FIG. 21 is a view for explaining the configuration of drawing data used in the embodiment of the present invention.

FIG. 22 is a diagram showing a relationship between a chip, a frame, and a subfield.

FIG. 23 is a view for explaining the configuration of drawing data in which subfield positions have been corrected.

FIG. 24 is a view for explaining the configuration of drawing data used in another embodiment of the present invention.

FIG. 25 is a diagram showing a relationship between a character code and a main deflection position deflection amount.

FIG. 26 is a schematic diagram of a configuration of a drawing control circuit used in an example of the present invention.

FIG. 27 is a schematic diagram of a configuration of a drawing control circuit used in an example of the present invention.

FIG. 28 is an explanatory diagram showing a method for creating drawing data and aperture creation data in the embodiment of the present invention.

FIG. 29 is a view for explaining a method of arranging the extracted character shapes on the aperture.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Sample room 11 ... Target (sample) 12 ... Sample stage (stage) 20 ... Electron optical system column 21 ... Electron gun 22a-22e ... Various lens systems 23-26 ... various deflection systems 27a ... blanking plate 27b ... first forming aperture mask 27c ... second forming aperture mask 31 ... sample drive circuit 32 ... laser length measuring instrument 33 ... deflection Control circuit unit 34 Blanking control circuit unit 35 Variable beam forming and character beam forming deflection circuit unit 36 Buffer memory and control circuit 37 Control computer 38 Data conversion and proximity effect Correction computer 39 ... CAD system 50 ... Area that cannot be drawn using the changed minimum unit character shape as it is 51, 71 ... Drawing data 52, 72 ... control computers 64, 84 ... data generators 53, 73 ... buffer memories 54, 74 ... data development shot division circuits 55, 75 ... main deflection calculation circuits 56, 76 ..Sub-deflection operation circuits 57, 77 ... molding deflection operation circuits 58, 59, 60, 78, 79, 80 ... D / A converters, deflection amplifiers 61, 81 ... main deflectors 62, 82 ... sub-deflectors 63, 83 ... forming deflectors 65, 85 ... objective deflection control circuits 66, 86 ... forming deflection control circuits 90 ... electron beams.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kiyoshi Hattori 33, Isoiso-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Production Engineering Laboratory Toshiba Corporation (72) Inventor Kanji Wada 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa (56) References JP-A-3-64016 (JP, A) JP-A-5-36593 (JP, A) JP-A-62-260322 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 7/20

Claims (1)

(57) [Claims] 1. A charged beam drawing apparatus for irradiating a charged beam on a sample to draw a desired pattern on the sample, wherein the shape of a figure which is at least the minimum unit of a variable shaped beam system and a repetitive pattern is determined by an electron optical system. In the region of the repetitive pattern, a character projection method for drawing using the shape of the figure that is the minimum unit formed in the aperture is provided.
If the shape of the outer frame of the minimum unit is rectangular, it is formed in the aperture as it is, and a desired pattern is drawn. If the shape of the outer frame of the figure of the minimum unit is not rectangular, the repetition pattern The minimum unit is changed so that the shape of the outer frame of the minimum unit becomes a rectangle, the minimum unit figure is formed in the aperture, and processing of the excess or deficiency pattern that occurs when a desired pattern is drawn is repeated. A drawing method using a pattern data designed to be processed by a pattern adjacent to the charged beam drawing method.