WO2023228675A1

WO2023228675A1 - Multi charged-particle beam irradiation device and multi charged-particle beam irradiation method

Info

Publication number: WO2023228675A1
Application number: PCT/JP2023/016484
Authority: WO
Inventors: 裕史松本
Original assignee: 株式会社ニューフレアテクノロジー
Priority date: 2022-05-24
Filing date: 2023-04-26
Publication date: 2023-11-30
Also published as: JP2023172433A

Abstract

A multi charged-particle beam irradiation device according to an aspect of the present invention is characterized by comprising: a shaping aperture array substrate that forms multi-beam arrays of a charged-particle beam; a limiting aperture array substrate in which a plurality of passing holes are formed through which at least some of the beams of the multi-beam arrays can pass, some of the plurality of passing holes having a shape different from that of the other passing holes; a mechanism for moving at least one of the shaping aperture array substrate, the limiting aperture array substrate, and the multi-beam arrays in a direction orthogonal to a trajectory central axis of the multi-beams so that the relative positions of the multi-beam arrays and the limiting aperture array substrate are changed; and an optical system that irradiates a sample with a beam array among the multi-beam arrays that has passed through the limiting aperture array substrate with the relative position to the multi-beam arrays having been moved to a predetermined position.

Description

Multi-charged particle beam irradiation device and multi-charged particle beam irradiation method

This application is an application claiming priority to JP2022-084226 (application number) filed in Japan on May 24, 2022 as the basic application. All contents described in JP2022-084226 are incorporated into this application by reference.

One aspect of the present invention relates to a multi-charged particle beam irradiation device and a multi-charged particle beam irradiation method, and relates, for example, to a method of selecting the amount of current of a beam array that irradiates a substrate in a multi-beam lithography device.

Lithography technology, which is responsible for the progress of miniaturization of semiconductor devices, is the only extremely important process in the semiconductor manufacturing process that generates patterns. In recent years, as LSIs have become more highly integrated, the circuit line width required for semiconductor devices has become smaller year by year. Here, electron beam (electron beam) writing technology inherently has excellent resolution, and writing is performed on wafers and the like using electron beams.

For example, there is a writing device that uses multiple beams. Compared to writing with a single electron beam, using multiple beams allows multiple beams to be irradiated at once, resulting in a significant improvement in throughput.

Here, in multi-beam writing, as the total current amount increases, the irradiation time can be shortened or the irradiation area can be increased, so the throughput can be increased. However, on the other hand, the drawing accuracy deteriorates because the Coulomb effect increases. Conversely, the smaller the total current amount, the smaller the Coulomb effect, and therefore the drawing accuracy can be improved. However, on the other hand, since the irradiation time becomes longer or the irradiation area becomes smaller, the throughput deteriorates. In this way, there is a trade-off relationship between throughput and drawing accuracy. However, in a drawing device, both processing that requires increasing throughput at the expense of drawing accuracy and processing that requires increasing drawing accuracy even at the cost of throughput can be performed. Therefore, it is desirable to have a configuration that allows switching between the large current amount mode and the small current amount mode. Such a problem is not limited to multi-beam lithography devices, but can similarly occur in irradiation devices that irradiate multi-beams, such as multi-beam inspection devices. Methods for reducing the total amount of current include reducing the beam size or reducing the number of beams.

Here, as a method to reduce the beam size, first and second shaping aperture arrays are arranged, and the multi-beam shaped by the first shaping aperture array is distributed between the first and second shaping aperture arrays. A method has been disclosed in which a multi-beam is re-shaped by a second shaping aperture array by deflecting it with an arranged deflector (see, for example, Patent Document 1).

Next, as a method to reduce the number of beams, the beam array on one side of the rectangular outer periphery of the multi-beam can be blocked by shifting the position of a shutter that has a large aperture that allows the entire multi-beam to pass through. is possible. Here, among the multiple beams, the beam closer to the outer circumference has a larger beam diameter at the crossover position, and leakage beams are more likely to occur during blanking deflection. Therefore, when reducing the number of beams, it is desirable to use the central beam array as much as possible. However, with such a method, it is not only difficult to shield the entire outer periphery of the multi-beam, but also difficult to shield both sides simultaneously.

JP2018-098242A

One aspect of the present invention provides a multi-beam irradiation device and method that can selectively switch between a large current amount mode and a small current amount mode.

A multi-charged particle beam irradiation device according to one embodiment of the present invention includes:
a shaped aperture array substrate forming a multi-beam array of charged particle beams;
a limiting aperture array substrate formed with a plurality of passage holes through which at least a portion of each beam of the multi-beam array can pass, and a shape of some of the passage holes of the plurality of passage holes is different from that of other passage holes;
At least one of the shaping aperture array substrate, the limiting aperture array substrate, and the multibeam array is disposed in a direction perpendicular to the orbit center axis of the multibeams so that the relative position between the multibeam array and the limiting aperture array substrate changes. a mechanism for moving the
an optical system that irradiates a sample with a beam array of the multi-beam array that has passed through a limited aperture array substrate whose position relative to the multi-beam array is set at a predetermined position by movement;
It is characterized by having the following.

A multi-charged particle beam irradiation method according to one embodiment of the present invention includes:
A multi-beam array is formed by a shaped aperture array in which a plurality of shaped openings are formed,
The multi-beam array is designed so that the relative position between the shaped aperture array substrate and the limiting aperture array substrate, in which a plurality of passage holes through which each beam of the multi-beam array can pass, is formed and the shape of the plurality of passage holes is different for each area changes. The relative position of the multi-beam array and the limiting aperture array substrate is varied by moving at least one of the shaping aperture array substrate, the limiting aperture array substrate, and the multi-beam array in a direction perpendicular to the center axis of the beam trajectory. ,
Of the multi-beam array, a beam array that has passed through a limited aperture array substrate whose position relative to the multi-beam array is set at a predetermined position by movement is irradiated onto the sample.
It is characterized by

According to one aspect of the present invention, multi-beam irradiation that can be selectively switched between a large current amount mode and a small current amount mode is possible.

1 is a conceptual diagram showing the configuration of a drawing device in Embodiment 1. FIG. 2 is a conceptual diagram showing the configuration of a molded aperture array substrate in Embodiment 1. FIG. 2 is a conceptual diagram showing the configuration of a limited aperture array substrate in Embodiment 1. FIG. FIG. 3 is a diagram for explaining the state of multi-beams depending on the relative positions of the shaping aperture array substrate and the limiting aperture array substrate in the first embodiment. FIG. 3 is a diagram for explaining the state of multi-beams depending on the relative positions of the shaping aperture array substrate and the limiting aperture array substrate in the first embodiment. FIG. 3 is a diagram for explaining the state of multi-beams depending on the relative positions of the shaping aperture array substrate and the limiting aperture array substrate in the first embodiment. FIG. 3 is a diagram illustrating an example of the shape of a passage hole of a limited aperture array substrate and a beam array passing therethrough in the first embodiment. FIG. 7 is a diagram illustrating another example of the shape of the passage hole of the limited aperture array substrate and the beam array passing therethrough in the first embodiment. FIG. 7 is a diagram illustrating another example of the shape of the passage hole of the limited aperture array substrate and the beam array passing therethrough in the first embodiment. 3 is a diagram showing an example of the relationship between a beam array area and a passage area in Embodiment 1. FIG. FIG. 3 is a diagram showing an example of a relationship table between sub-regions of the beam array region and passing regions in the first embodiment. 3 is a diagram showing an example of the shape of a passage hole of a limited aperture array substrate in Embodiment 1. FIG. 3 is a diagram showing an example of the shape of a passage hole of a limited aperture array substrate in Embodiment 1. FIG. 3 is a diagram showing an example of the shape of a passage hole of a limited aperture array substrate in Embodiment 1. FIG. 3 is a diagram showing an example of the shape of a passage hole of a limited aperture array substrate in Embodiment 1. FIG. 7 is a diagram showing another example of the relationship between the beam array area and the passage area in the first embodiment. FIG. 7 is a diagram illustrating another example of a relationship table between sub-regions of the beam array region and passage regions in Embodiment 1. FIG. 7 is a diagram showing another example of the shape of the passage hole of the limited aperture array substrate in the first embodiment. FIG. 7 is a diagram showing another example of the shape of the passage hole of the limited aperture array substrate in the first embodiment. FIG. 7 is a diagram showing another example of the shape of the passage hole of the limited aperture array substrate in the first embodiment. FIG. FIG. 3 is a conceptual top view showing a part of the configuration within the membrane region of the blanking aperture array mechanism in Embodiment 1. FIG. FIG. 3 is a conceptual diagram for explaining an example of a region to be drawn in the first embodiment. FIG. 3 is a diagram showing an example of a multi-beam irradiation area and pixels to be drawn in the first embodiment. FIG. 3 is a conceptual diagram showing the configuration of a limited aperture array substrate in Embodiment 2. FIG. FIG. 7 is a diagram for explaining the state of multi-beams depending on the relative positions of the shaping aperture array substrate and the limiting aperture array substrate in Embodiment 2; FIG. 7 is a diagram for explaining the state of multi-beams depending on the relative positions of the shaping aperture array substrate and the limiting aperture array substrate in Embodiment 2;

In the following embodiments, a configuration using an electron beam as an example of a charged particle beam will be described. However, the charged particle beam is not limited to an electron beam, and may be a beam using charged particles such as an ion beam. Furthermore, a multi-electron beam lithography system will be described as an example of a multi-charged particle beam irradiation system. The irradiation device is not limited to a drawing device, but may be an exposure device, an inspection device, or the like.

[Embodiment 1]
FIG. 1 is a conceptual diagram showing the configuration of a drawing apparatus in the first embodiment. In FIG. 1, a drawing apparatus 100 includes a drawing mechanism 150 and a control system circuit 160. The drawing apparatus 100 is an example of a multi-charged particle beam drawing apparatus, and also an example of a multi-charged particle beam irradiation apparatus. The drawing mechanism 150 includes an electron lens barrel 102 (electron beam column) and a drawing chamber 103. Inside the electron lens barrel 102, there are an electron gun 201, an illumination lens 202, a shaped aperture array substrate 203, a limiting aperture array substrate 212, a blanking aperture array mechanism 204, a reduction lens 205, a limiting aperture substrate 206, an objective lens 207, and a main deflector. A deflector 208, a sub-deflector 209, and a drive circuit 214 are arranged. An XY stage 105 is arranged inside the drawing chamber 103. On the XY stage 105, a sample 101 such as a mask, which becomes a substrate to be drawn during drawing (during exposure), is arranged. The sample 101 includes an exposure mask used in manufacturing a semiconductor device, a semiconductor substrate (silicon wafer) on which a semiconductor device is manufactured, and the like. Further, the sample 101 includes a mask blank coated with resist but on which nothing has been drawn yet. A mirror 210 for position measurement of the XY stage 105 is further arranged on the XY stage 105.

The control system circuit 160 includes a control computer 110, a memory 112, a deflection control circuit 130, an aperture array control circuit 131, digital-to-analog conversion (DAC)

amplifier units

132 and 134, a lens control circuit 136, a stage control mechanism 138, and a stage position measurement circuit. 139 and

storage devices

140 and 142 such as magnetic disk devices. The control computer 110, memory 112, deflection control circuit 130, aperture array control circuit 131, lens control circuit 136, stage control mechanism 138, stage position measuring device 139, and

storage devices

140, 142 are connected to each other via a bus (not shown). ing. The deflection control circuit 130 is connected to

DAC amplifier units

132 and 134 and a blanking aperture array mechanism 204. The sub-deflector 209 is composed of four or more electrodes, and each electrode is controlled by the deflection control circuit 130 via the DAC amplifier 132. The main deflector 208 is composed of four or more electrodes, and each electrode is controlled by the deflection control circuit 130 via a DAC amplifier 134. The illumination lens 202, the reduction lens 205, and the objective lens 207 are connected to the lens control circuit 136 and controlled respectively. The stage position measuring device 139 measures the position of the XY stage 105 using the principle of laser interferometry by receiving the reflected light from the mirror 210. A drive circuit 214 is connected to the aperture array control circuit 131 . Drive circuit 214 moves at least one of shaping aperture array substrate 203 and limiting aperture array substrate 212. The example in FIG. 1 shows a case where the drive circuit 214 moves the limited aperture array substrate 212.

Inside the control computer 110, a shot data generation section 62, a data processing section 64, a mode selection section 66, a transfer control section 79, and a drawing control section 80 are arranged. Each of the "sections" such as the shot data generation section 62, the data processing section 64, the mode selection section 66, the transfer control section 79, and the drawing control section 80 has a processing circuit. Such processing circuits include, for example, electrical circuits, computers, processors, circuit boards, quantum circuits, or semiconductor devices. Each "~ section" may use a common processing circuit (the same processing circuit) or may use different processing circuits (separate processing circuits). Information input/output to/from the shot data generation section 62, data processing section 64, mode selection section 66, transfer control section 79, and drawing control section 80 and information being calculated are stored in the memory 112 each time.

The drawing operation of the drawing device 100 is controlled by the drawing control unit 80. Further, the process of transferring the irradiation time data of each shot to the deflection control circuit 130 is controlled by the transfer control unit 79.

Additionally, chip data (drawing data) is input from outside the drawing apparatus 100 and stored in the storage device 140. The chip data defines information on a plurality of graphic patterns that constitute a chip to be drawn. Specifically, for example, a graphic code, coordinates, size, etc. are defined for each graphic pattern.

Here, FIG. 1 shows the configuration necessary for explaining the first embodiment. The drawing apparatus 100 may normally include other necessary configurations.

FIG. 2 is a conceptual diagram showing the configuration of the molded aperture array substrate in the first embodiment. In FIG. 2, a molded aperture array substrate 203 has openings (molded openings) 22 arranged in a matrix of p columns horizontally (x direction) x q stages vertically (y direction) (p, q≧2) at a predetermined arrangement pitch. It is formed in the shape of The example in FIG. 2 shows a case where, for example, the openings 22 are formed in eight rows and seven stages in the horizontal and vertical directions (x, y directions). The number of openings 22 is not limited to this. For example, the openings 22 may be formed in 512 rows and 512 stages. Each opening 22 is formed in a rectangular shape with the same size and shape. Alternatively, they may be circular with the same diameter. A multi-beam 20 is formed by a portion of the electron beam 200 passing through each of the plurality of apertures 22 . In other words, shaped aperture array substrate 203 forms multiple beams 20 .

FIG. 3 is a conceptual diagram showing the configuration of the limited aperture array substrate in the first embodiment. In FIG. 3, a plurality of passage holes 21 and 23, the same number as the number of beams of the multi-beam 20, are formed in a limited aperture array substrate 212. The plurality of passage holes 21 and 23 are formed at each position (starting point) arranged at the beam pitch (Px, Py) of the multi-beam 20 on the limited aperture array substrate 212 so that the beam can pass therethrough. In FIG. 3, the shape of some of the plurality of passage holes 23 is different from that of the other passage holes 21. In FIG. In the example of FIG. 3, among the plurality of passage holes of the multi-beam 20, the shape of the plurality of central passage holes 23 for the central beam array is different from the shape of the plurality of peripheral passage holes 21 for the peripheral beam groups. It differs from the shape. As the basic shape of the plurality of passage holes 21, for example, a square having a size equal to one beam size plus a margin is used. On the other hand, as the shape of the plurality of irregularly shaped passage holes 23, for example, a rectangle that is laterally elongated in the x direction is used. The length of the rectangle in the longitudinal direction (x direction) is formed to be at least twice the size of each beam in the x direction. For example, a rectangle whose size is the size of the basic shape plus one beam size plus a margin in the +x direction is used. In other words, in the plurality of passage holes, the area of the passage hole 23 formed in the center portion is larger than the area of the passage hole 21 formed in the outer peripheral portion.

Next, a specific example of the operation of the drawing mechanism 150 will be described. An electron beam 200 emitted from an electron gun 201 (emission source) illuminates the entire shaped aperture array substrate 203 almost vertically by an illumination lens 202. A plurality of rectangular openings 22 are formed in the shaped aperture array substrate 203, and the electron beam 200 illuminates a region including all the plurality of openings 22. Each part of the electron beam 200 irradiated to the positions of the plurality of openings 22 passes through the plurality of openings 22 of the shaped aperture array substrate 203, so that, for example, a rectangular multi-beam (multiple electron beams) is formed. ) 20 are formed. After passing through the shaping aperture array substrate 203, the multibeam 20 advances to the limiting aperture array substrate 212. The drive mechanism 214 changes the relative position of the shaping aperture array substrate 203 and the limiting aperture array substrate 212 depending on the mode selected from among a plurality of modes in which the beam array irradiates the sample 101 with different amounts of current. At least one of the shaping aperture array substrate 203 and the limiting aperture array substrate 212 is moved in a direction perpendicular to the orbit center axis of the multi-beam 20 so as to move.

FIGS. 4A to 4C are diagrams for explaining the state of the multi-beam according to the relative positions of the shaping aperture array substrate and the limiting aperture array substrate in the first embodiment. By the driving mechanism 214 moving at least one of the shaped aperture array substrate 203 and the limiting aperture array substrate 212, the limiting aperture array substrate 212 is moved according to the relative position of the shaped aperture array substrate 203 and the limiting aperture array substrate 212. , selectively passes either the entire multi-beam 20 or a part of the beam array of the entire multi-beam 20. The example in FIG. 4A shows a case where the entire multi-beam 20 is selectively passed through. In the example of FIG. 4A, all the beams 13 of the multi-beam 200 that have passed through the plurality of apertures 22 of the shaped aperture array substrate 203 are inside any one of the plurality of passage holes 21 and 23 of the limiting aperture array substrate 212. This shows the case where the area overlaps with the position of the area. In the example of FIG. 4A, all beams 13 of multi-beam 20 are allowed to pass through restricted aperture array substrate 212. In other words, the sample 101 is irradiated with a beam array with a large amount of current.

In the example of FIG. 4B, the driving mechanism 214 moves at least one of the shaping aperture array substrate 203 and the limiting aperture array substrate 212, so that the limiting aperture array substrate 212 variably shapes the size of the multibeam 20. In the example of FIG. 4B, for example, each of the multibeams 200 that has passed through the plurality of openings 22 of the shaping aperture array substrate 203 is A case is shown in which the relative position of the beam 13 is shifted so that it partially overlaps each of the plurality of passage holes 21 and 23 of the limiting aperture array substrate 212. As a result, in the example of FIG. 4B, each beam 13 overlaps with the upper left corner of the plurality of passage holes 21 and 23, and a portion of each beam 13 can pass through the limiting aperture array substrate 212, respectively. In other words, the multi-beam 20 shaped by the shaping aperture array substrate 203 is reshaped by the limiting aperture array substrate 212 so that the beam size becomes smaller (two-stage shaping). In the example of FIG. 4B, the beam size of the multi-beam 20 can be reduced to 1/4, for example, by two-stage forming. By adjusting the relative positional relationship between the shaping aperture array substrate 203 and the limiting aperture array substrate 212, each beam 13 can be variably shaped. Thereby, the beam size of each beam of the multi-beam 20 can be reduced. Therefore, the total amount of current flowing through the multi-beam 20 can be reduced.

In the example of FIG. 4C, the drive mechanism 214 moves at least one of the shaped aperture array substrate 203 and the limiting aperture array substrate 212, so that the limiting aperture array substrate 212 moves between the shaped aperture array substrate 203 and the limiting aperture array substrate 212. A case is shown in which a part of the beam array of the entire multi-beam 20 is selectively passed according to the relative position of the beam array. The limiting aperture array substrate 212 allows the central beam array of the entire multi-beam 20 to pass, when such a part of the beam array passes. The example of FIG. 4C shows a case where, for example, the limited aperture array substrate 212 is shifted in the x direction by a larger amount than the beam size of the multi-beam 20. As a result, in the example of FIG. 4C, among the multi-beams 200 that have passed through the plurality of openings 22 of the shaped aperture array substrate 203, the beam 13 corresponding to the horizontally elongated passage hole 23 in the x direction of the limited aperture array substrate 212 passes through. It can pass through the hole 23. However, since the beam 13 corresponding to the square passage hole 21 is out of position from the passage hole 21, it is blocked by the limiting aperture array substrate 212. In the example of FIG. 4C, among the multi-beams 200, the central beam arrays can each pass through the passage holes 23. However, the beam group at the periphery cannot pass through the passage hole 21 and is blocked. Thereby, the number of beams of the multi-beam 20 can be reduced. In the example of FIG. 4C, the 8x7 beam array can be limited to a 4x5 beam array. Therefore, the total amount of current flowing through the multi-beam 20 can be reduced. Furthermore, the central beam array can be selectively extracted.

The multi-beam state described above can be achieved by moving at least one of the shaping aperture array substrate 203 and the limiting aperture array substrate 212 using the drive circuit 214. In the above example, a case has been described in which one of two groups is selected as the beam array passing through the limited aperture array substrate 212: the entire multi-beam 200 and the central beam array of the multi-beam 200. By further subdividing the shapes of the irregularly shaped passage holes in the limited aperture array substrate 212, the number of selectable beam array groups can be further increased. Note that although the drive mechanism 214 mechanically changes the relative position between the shaping aperture array substrate 203 and the limiting aperture array substrate 212, it is also possible to change the relative position by deflecting the electron beam 200 using the drive mechanism 214. good.

FIG. 5 is a diagram showing an example of the shape of the passage hole of the limited aperture array substrate and the beam array passing through in the first embodiment. In the example of FIG. 5, a region R1 is defined from a region through which, for example, a 256×256 beam array in the center of the 512×512 multibeams 20 irradiated onto the limited aperture array substrate 212; The beam array area on the limited aperture array substrate 212 is divided into three groups: a region R2 excluding the region R1 from the region through which the 384×384 beam array passes, and a remaining region R3 surrounding the region R2. Starting from each position arranged at the beam pitch on the limited aperture array substrate 212 where the 512 x 512 multi-beams 20 are irradiated, from the starting point, for example, relative to the -x direction by one beam size + margin. The shifted position of the irradiation position is set to a position that limits the beam array to 384 x 384 beams. For example, a position where the irradiation position is relatively shifted by one beam size + margin in the +x direction from the starting point is set as a position that limits the beam array to 256 x 256 beams. Regarding the 256×256 passage holes 23b formed in the region R1, a starting point arranged at the beam pitch, a position where the irradiation position is relatively shifted by one beam size + margin from the starting point in the -x direction, The beam is formed into a shape that allows the beam to pass through all positions where the irradiation position is relatively shifted by one beam size + margin in the +x direction from the starting point. Here, it is formed into a rectangle with a length more than three times (1 beam size + margin) in the x direction. Regarding each passage hole 23a formed in region R2, the beam can pass between the starting points arranged at the beam pitch and the position where the irradiation position is relatively shifted by one beam size + margin in the -x direction. Therefore, the beam is formed in such a shape that the beam cannot pass through the position where the irradiation position is relatively shifted by one beam size + margin in the +x direction. Here, each passage hole 23a is formed in a rectangular shape having a length in the x direction that is more than twice (1 beam size + margin) and shorter than the passage hole 23b. Each passage hole 21 formed in the region R3 is formed in a shape that allows the beam to pass only at the starting points arranged at the beam pitch. Here, each passage hole 21 is formed into a square with a size of (1 beam size + margin), for example. Note that the size of each of the passage holes 21, 23a, and 23b in the y direction may be the same size as 1 beam size+margin. In the example of FIG. 5, all beams 13 of the 512×512 multi-beams 20 that have passed through the shaped aperture array substrate 203 are restricted to positions where they can pass through the corresponding passage holes 21 (23a or 23b) in each area. A case is shown in which the aperture array substrate 212 is being adjusted.

FIG. 6 is a diagram showing another example of the shape of the passage hole of the limited aperture array substrate and the beam array passing through in the first embodiment. From the state shown in FIG. 5, the irradiation position of each beam on the limiting aperture array substrate 212 is shifted in the -x direction by one beam size + margin, that is, the limiting aperture array substrate 212 is shifted relative to the position shown in FIG. A state in which the beam is moved by one beam size + margin in the x direction is shown. Alternatively, the shaped aperture array substrate 203 may be moved in the -x direction by one beam size plus a margin. Alternatively, the limiting aperture array substrate 212 is moved in the x direction by (1 beam size + margin) x L (where L is 0<L<1), and the shaping aperture array substrate 203 is moved in the -x direction by (1 beam size + margin) x L (where L is 0<L<1). It is also possible to move by beam size + margin) x (1-L). As a result, in the region R3, the position of the passage hole 21 deviates from the position of the beam 13, so each beam 13 in the region R3 is blocked by the limiting aperture array substrate 212. In regions R1 and R2, each beam 13 in regions R1 and R2 passes through the limiting aperture array substrate 212 because the passage holes 23b and 23a are in positions that include the beams 13 within the passage holes. Therefore, the 512 x 512 multi-beams 20 can be limited to the 384 x 384 beam array in the center.

Further, from the state shown in FIG. 5, the irradiation position of each beam on the limiting aperture array substrate 212 is relatively shifted in the x direction by one beam size + margin, that is, the limiting aperture array substrate 212 When moved in the -x direction by one beam size + margin, the positions of the passage holes 21 and 23a are moved from the position of the beam 13 in the regions R3 and R2, so each beam 13 in the regions R3 and R2 has a limiting aperture. It is shielded by the array substrate 212. In region R1, each beam 13 in region R1 passes through limiting aperture array substrate 212 because the passage hole 23b is at a position that includes the beam 13 within the passage hole. Alternatively, the shaped aperture array substrate 203 may be moved in the +x direction by one beam size + margin. Alternatively, the limiting aperture array substrate 212 is moved in the −x direction by (1 beam size + margin)×L (where L is 0<L<1), and the shaping aperture array substrate 203 is moved in the +x direction by (1 beam size + margin)×L (where L is 0<L<1). It is also possible to move by beam size + margin) x (1-L). Thereby, the 512 x 512 multi-beams 20 can be limited to the 256 x 256 beam array in the center.

In the examples of FIGS. 5 and 6 described above, by moving the limiting aperture array substrate 212 (or the shaped aperture array substrate 203) in the x direction, the beam array passing through the limiting aperture array substrate 212 is changed to the case of the entire multi-beam 200. A case has been described in which one of three groups can be selected: a 384×384 beam array in the center, and a 256×256 beam array in the center. By further improving the shape of the irregularly shaped passage holes in the limited aperture array substrate 212, the number of selectable beam array groups can be further increased.

FIG. 7 is a diagram showing another example of the shape of the passage hole of the limited aperture array substrate and the beam array passing through in the first embodiment. In FIG. 7, by moving the limiting aperture array substrate 212 (or the shaped aperture array substrate 203) in the x and y directions, it is possible to select one of five groups of beam arrays that pass through the limiting aperture array substrate 212. Make it. In the example of FIG. 7, among the 512 x 512 multi-beams 20 irradiated onto the limited aperture array substrate 212, there is a region r1 in the center through which, for example, a 128 x 128 beam array passes, and a region r1 in the center, for example, 256 A region r2, which is obtained by excluding region r1 from the region through which 256 beam arrays pass, a region r3, which is obtained by removing regions r1 and r2 from the region through which 384×384 beam arrays pass, for example, in the center, and The beam array on the limited aperture array substrate 212 is divided into five groups: a region r4 obtained by excluding regions r1, r2, and r3 from the region through which the 448×448 beam array passes, and a remaining region r5 surrounding the region r4. Separate areas. Starting from each position arranged at a beam pitch on the limited aperture array substrate 212 where 512 x 512 multi-beams 20 are irradiated, the irradiation is performed relatively from the starting point by, for example, one beam size + margin in the +y direction. The shifted position is set to a position that limits the beam array to 128 x 128 beams. Further, a position where the irradiation position is relatively shifted from the starting point by, for example, one beam size + margin in the −x direction is set as a position that limits the beam array to 256×256 beams. Further, a position where the irradiation position is relatively shifted from the starting point by, for example, one beam size + margin in the −y direction is set as a position that limits the beam array to 384×384 beams. Further, a position where the irradiation position is relatively shifted from the starting point by, for example, one beam size + margin in the +x direction is set as a position that limits the beam array to 448 x 448 beams.

In the example of FIG. 7, the plurality of passage holes 21, 23a, 23c, 23d, and 23e are formed, for example, by a combination of a rectangle and a shape different from the rectangle. This will be explained in detail below.

Regarding the 128 x 128 passage holes 23e formed in the region r1, there are a starting point arranged at the beam pitch, a position where the irradiation position is relatively shifted by one beam size + margin in the +y direction from the starting point, and a starting point. A position where the irradiation position is relatively shifted by 1 beam size + margin in the -x direction from the origin, a position where the irradiation position is relatively shifted by 1 beam size + margin in the -y direction from the origin, and +x from the origin The beam is formed into a shape that allows the beam to pass through both the positions where the irradiation position is relatively shifted by one beam size + margin in the direction. In the example of FIG. 7, the passage hole 23e is formed in a cross shape.

For each passage hole 23d formed in region r2, there are starting points arranged at the beam pitch, a position where the irradiation position is relatively shifted by one beam size + margin in the -x direction from the starting point, and -y from the starting point. The beam can pass through a position where the irradiation position is relatively shifted by 1 beam size + margin in the direction, and a position where the irradiation position is relatively shifted by 1 beam size + margin in the +x direction from the origin. formed into a shape. In the example of FIG. 7, the passage hole 23d is formed in a convex shape that is convex in the -y direction.

For each passage hole 23c formed in region r3, there are starting points arranged at the beam pitch, a position where the irradiation position is relatively shifted by one beam size + margin in the -y direction from the starting point, and a position in the +x direction from the starting point. The beam is formed into a shape that allows the beam to pass through the position where the irradiation position is relatively shifted by one beam size + margin. In the example of FIG. 7, the passage hole 23c is formed in an L-shape extending in the +x direction and the -y direction.

For each passage hole 23a formed in the region r4, the beam passes through the starting points arranged at the beam pitch and at the position where the irradiation position is relatively shifted by one beam size + margin from the starting point in the +x direction. formed into any possible shape. In the example of FIG. 7, the passage hole 23a is formed into a rectangle extending in the +x direction.

Each passage hole 21 formed in the region r5 is formed in a shape that allows the beam to pass through the starting points arranged at the beam pitch. In the example of FIG. 7, the passage hole 21 is formed in a square shape.

When the irradiation position of each beam on the limiting aperture array substrate 212 is each starting point arranged at a beam pitch, that is, when the limiting aperture array substrate 212 is adjusted to a position matching each starting point, r1 to r5 The entire 512×512 multi-beams 20 pass through the limited aperture array substrate 212.

For example, the irradiation position of each beam on the limited aperture array substrate 212 is a position relatively shifted by one beam size + margin in the +x direction from each starting point arranged at the beam pitch, that is, When the limiting aperture array substrate 212 is moved from the starting point in the -x direction by one beam size + margin, the position of the passage hole 21 is deviated from the position of the beam 13 in the region r5, so each beam 13 in the region r5 is restricted. It is shielded by an aperture array substrate 212. In the regions r1 to r4, each beam 13 in the regions r1 to r4 passes through the limiting aperture array substrate 212 because the passage holes 23e, 23d, 23c, and 23a are in positions that include the beams 13 within the passage holes. Therefore, the 512 x 512 multi-beams 20 can be limited to the 448 x 448 beam array at the center. Alternatively, the shaped aperture array substrate 203 may be moved in the +x direction by one beam size + margin. Alternatively, the limiting aperture array substrate 212 is moved in the −x direction by (1 beam size + margin)×L (where L is 0<L<1), and the shaping aperture array substrate 203 is moved in the +x direction by (1 beam size + margin)×L (where L is 0<L<1). It is also possible to move by beam size + margin) x (1-L). The moving method for shifting the relative positions of the shaped aperture array substrate 203 and the limited aperture array substrate 212 is the same below.

For example, the irradiation position of each beam on the limited aperture array substrate 212 is a position relatively shifted by one beam size + margin in the −y direction from each starting point arranged at the beam pitch, that is, , when the limited aperture array substrate 212 is moved in the +y direction from the starting point by one beam size + margin, the positions of the passage holes 21 and 23a are deviated from the position of the beam 13 in areas r5 and r4, so Each beam 13 of is blocked by a limiting aperture array substrate 212. In the regions r1 to r3, each beam 13 in the regions r1 to r3 passes through the limiting aperture array substrate 212 because the passage holes 23e, 23d, and 23c are in positions that include the beams 13 within the passage holes. Therefore, the 512 x 512 multi-beams 20 can be limited to the 384 x 384 beam array in the center.

For example, the irradiation position of each beam on the limited aperture array substrate 212 is a position relatively shifted by one beam size + margin in the −x direction from each starting point arranged at the beam pitch, that is, , when the limited aperture array substrate 212 is moved from the starting point in the +x direction by one beam size + margin, the positions of the passage holes 21, 23a, 23c will deviate from the position of the beam 13 in regions r5, r4, and r3, so Each beam 13 in regions r5, r4, and r3 is blocked by a restricted aperture array substrate 212. In the regions r1 to r2, each beam 13 in the regions r1 to r2 passes through the limited aperture array substrate 212 because the passage holes 23e and 23d are in positions that include the beams 13 within the passage holes. Therefore, the 512×512 multi-beams 20 can be limited to the 256×256 beam array in the center.

For example, the irradiation position of each beam on the limited aperture array substrate 212 is a position relatively shifted by one beam size + margin in the +y direction from each starting point arranged at the beam pitch, that is, When the limited aperture array substrate 212 is moved from the starting point in the -y direction by one beam size + margin, the positions of the passage holes 21, 23a, 23c, and 23d will deviate from the position of the beam 13 in regions r5 to r2, so Each beam 13 in regions r5-r2 is blocked by a restricted aperture array substrate 212. In region r1, each beam 13 in region r1 passes through the limiting aperture array substrate 212 because the passage hole 23e is at a position that includes the beam 13 within the passage hole. Therefore, the 512 x 512 multi-beams 20 can be limited to the 128 x 128 beam array at the center.

Next, an example of a method for determining the shape of the passage hole formed in the limited aperture array substrate 212 will be described.

FIG. 8 is a diagram showing an example of the relationship between the beam array area and the passing area in the first embodiment. In FIG. 8, the beam array area 31 of the entire multi-beam 20 is divided into sub-areas 1 to 9. Sub-region 1 is a region at the upper left corner of beam array region 31. Sub-region 3 is a region at the upper right corner of beam array region 31. The sub-region 7 is a region at the lower left corner of the beam array region 31. The sub-region 9 is a region at the lower right corner of the beam array region 31. Sub-region 2 is a region obtained by excluding

sub-regions

1 and 3 from the upper end region of beam array region 31. Sub-region 4 is a region obtained by excluding

sub-regions

1 and 7 from the left end region of beam array region 31. Sub-region 6 is a region obtained by excluding

sub-regions

3 and 9 from the right end region of beam array region 31. Sub-region 8 is a region obtained by excluding

sub-regions

7 and 9 from the lower end region of beam array region 31. Sub-region 5 is a central region of beam array region 31 excluding sub-regions 1 to 4 and 6 to 9 around it. Passage areas A to D are then set to determine the beam array that passes through the limited aperture array substrate 212. In the passage area A, the entire multi-beam 20 (for example, a 512×512 beam array) is allowed to pass through. In the passage area B, a beam array at the center of the multi-beam 20 in which passage of the beams at the upper, lower, left, and right ends is restricted is passed (for example, a 384×384 beam array). In the passage area C, a beam array in the central part of the multi-beam 20 in which passage of the upper and lower end beams is restricted is allowed to pass (for example, a 512 x 384 beam array). In the passage area D, a central beam array (for example, a 384×512 beam array) in which passage of the left and right end beams of the multi-beam 20 is restricted is allowed to pass.

FIG. 9 is a diagram showing an example of a relationship table between sub-regions of the beam array region and passing regions in the first embodiment. In FIG. 9, the vertical axis represents the sub-region shown in FIG. The horizontal axis shows the passage area shown in FIG. In FIG. 9, in order for the beam groups of

sub-regions

1, 3, 7, and 9 to pass through the restricted aperture array substrate 212, it is necessary to set a passage area A, and they cannot pass through the passage areas B to D. (off). In order for the beam groups of

sub-regions

2 and 8 to pass through the limited aperture array substrate 212, it is necessary to set the passing region A or D, and the beams cannot pass in the passing regions B and C (off). In order for the beam groups of

sub-regions

4 and 6 to pass through the limited aperture array substrate 212, it is necessary to set the passing region A or C, and the beams cannot pass in the passing regions B and D (off). In order for the beam group of the sub-region 5 to pass through the limited aperture array substrate 212, any of the passing regions A to D may be set.

FIGS. 10A to 10D are diagrams showing an example of the shape of the passage hole of the limited aperture array substrate in the first embodiment. When determining the shape of the passage hole on the limited aperture array substrate 212, it is preferable to determine the shape using the following method, for example. In the example of FIGS. 10A to 10D, first, the passage area A of FIG. 8 is set at each position (starting point) arranged at a beam pitch on the limited aperture array substrate 212 where the multi-beam 20 is irradiated. Then, the passage area B in FIG. 8 is set at a position where the irradiation position is relatively shifted from the starting point by, for example, one beam size + margin in the +y direction. The passage area C in FIG. 8 is set at a position where the irradiation position is relatively shifted from the starting point by, for example, one beam size + margin in the +x direction. The passage area D in FIG. 8 is set at a position where the irradiation position is relatively shifted from the starting point by, for example, one beam size + margin in the −y direction.

Referring to the relationship table in FIG. 9, for each passing hole formed in the limited aperture array substrate 212 for the beam of sub-region 5, the positions (starting points) (passing area A) arranged at the beam pitch, and the starting point For example, the position where the irradiation position is relatively shifted by 1 beam size + margin in the +y direction (passing area B) and the irradiation position relative to the starting point by 1 beam size + margin in the +x direction from the starting point, for example. The beam passes through both the position where the beam is shifted (passing area C) and the position where the irradiation position is relatively shifted by one beam size + margin from the origin in the -y direction (passing area D). formed into any possible shape. In the example of FIG. 10(d), the passage hole is formed in a convex shape that is convex in the +x direction.

Referring to the relational table in FIG. 9, for each passage hole formed in the limiting aperture array substrate 212 for the beams of

sub-regions

2 and 8, the positions (starting points) (passing area A) arranged at the beam pitch and , at a position (passing region D) where the irradiation position is relatively shifted from the starting point by, for example, one beam size + margin in the -y direction, and is formed into a shape that allows the beam to pass. In the example of FIG. 10B, the passage hole is formed into a rectangle extending in the -y direction.

sub-regions

4 and 6, the positions (starting points) (passing area A) arranged at the beam pitch and , is formed into a shape that allows the beam to pass at a position (passage area C) where the irradiation position is relatively shifted by one beam size + margin in the +x direction from the starting point, for example. In the example of FIG. 10C, the passage hole is formed in a rectangular shape extending in the +x direction.

Referring to the relationship table in FIG. 9, for each passage hole formed in the limiting aperture array substrate 212 for the beams of

sub-regions

1, 3, 7, and 9, the positions (starting points) (passing points) arranged at the beam pitch are determined. Only area A) is formed in a shape that allows the beam to pass through. In the example of FIG. 10A, the passage hole is formed in a square shape.

Next, an example of a method for determining the shape of the passage hole formed in the limited aperture array substrate 212 when the passage area is further subdivided will be described.

FIG. 11 is a diagram showing another example of the relationship between the beam array area and the passage area in the first embodiment. In FIG. 11, the beam array area 31 of the entire multi-beam 20 is divided into sub-areas 1 to 25. The beam array area 31 is divided in the x direction at the positions of the 64th beam, the 128th beam, the 384th beam, and the 448th beam. Similarly, the beam is divided at the positions of the 64th beam, the 128th beam, the 384th beam, and the 448th beam in the y direction. Thus, for example, sub-region 1 is the upper left corner region of beam array region 31. Specifically, the 1st to 64th beams in the x direction and the 449th to 512th beams in the y direction are targeted. Sub-region 2 is an upper region of beam array region 31, and targets the 65th to 128th beams in the x direction and the 449th to 512th beams in the y direction. The sub-region 3 is an upper region of the beam array region 31, and targets the 129th to 384th beams in the x direction and the 449th to 512th beams in the y direction. The sub-region 4 is an upper region of the beam array region 31, and targets the 385th to 448th beams in the x direction and the 449th to 512th beams in the y direction. The sub-region 5 is an upper region of the beam array region 31, and targets the 449th to 512th beams in the x direction and the 449th to 512th beams in the y direction. The areas that can be passed through are limited below. For example, the sub-region 13 is a central region of the beam array region 31, and targets the 129th to 384th beams in the x direction and the 129th to 384th beams in the y direction. The sub-region 25 is a region at the lower right corner of the beam array region 31, and targets the 449th to 512th beams in the x direction and the 1st to 64th beams in the y direction.

Then, in FIG. 11, a plurality of passing regions are set to determine the beam array that passes through the limited aperture array substrate 212. The entire multi-beam 20 is allowed to pass through the passage area (512). In the passage area (384), the central 384×384 beam array of the multi-beams 20 is passed. In the passage area (256), the central 256×256 beam array of the multi-beams 20 is allowed to pass. In the passing region (384'), the central 384×512 beam array of the multi-beams 20 is passed in the x direction. In the passing region (256'), the central 256×512 beam array of the multi-beams 20 is passed in the x direction. In the passing region (384"), the central 512 x 384 beam array of the multi-beam 20 in the y direction passes through. In the passing region (256"), the central 512 x 384 beam array in the y direction of the multi-beam 20 passes through. x256 beam array is passed.

FIG. 12 is a diagram showing another example of the relationship table between the sub-regions of the beam array region and the passage region in the first embodiment. In FIG. 12, the vertical axis represents the sub-region shown in FIG. 11. The horizontal axis indicates the passage area shown in FIG. 11. In FIG. 12, in order for the beam groups of

sub-regions

1, 5, 21, and 25 to pass through the limiting aperture array substrate 212, it is necessary to set a passing region (512); I can't do it (off).

In order for the beam groups of

sub-regions

2, 4, 22, and 24 to pass through the limited aperture array substrate 212, it is necessary to set a passing region (512) or (384'), and in other passing regions Cannot pass (off).

In order for the beam groups of

sub-regions

3 and 23 to pass through the limited aperture array substrate 212, it is necessary to set a passing region (512), (384'), or (256'), and other passing regions must be set. Cannot pass through the area (off).

In order for the beam groups of

sub-regions

6, 10, 16, and 20 to pass through the limiting aperture array substrate 212, it is necessary to set a passage area (512) or (384''), and other passage areas. It cannot pass (off).

In order for the beam groups of

sub-regions

7, 9, 17, and 19 to pass through the limited aperture array substrate 212, a passing region (512), (384), (384') or (384'') may be set. It is necessary and cannot be passed in other passing areas (off).

In order for the beam groups of sub-regions 8 and 18 to pass through the limited aperture array substrate 212, a passing region (512), (384), (384'), (256'), or (384'') is set. It must be possible to pass through other passing areas (off).

In order for the beam groups of sub-regions 11 and 15 to pass through the limited aperture array substrate 212, it is necessary to set a passing region (512), (384"), or (256"), and other passing regions are required. Cannot pass through the area (off).

In order for the beam groups of the sub-regions 12 and 14 to pass through the limited aperture array substrate 212, a passing region (512), (384), (384'), (384''), or (256'') is set. It must be possible to pass through other passing areas (off).

In order for the beam group of the sub-region 13 to pass through the limited aperture array substrate 212, the passing regions (512), (384), (256), (384'), (256'), (384''), (256 ”) may be set.

FIGS. 13A to 13C are diagrams showing other examples of the shapes of the passage holes of the limited aperture array substrate in Embodiment 1. When determining the shape of the passage hole on the limited aperture array substrate 212, it is preferable to determine the shape using the following method, for example. In the examples shown in FIGS. 13A to 13C, first, the passage areas (512) in FIG. 11 are set at each position (starting point) arranged at the beam pitch on the limited aperture array substrate 212 where the multi-beam 20 is irradiated. In the examples shown in FIGS. 13A to 13C, seven positions are required for the limiting aperture array substrate 212, so the size of each side of the passage area (512) is set to twice the size of (1 beam size + margin). Set. The starting point may be set at the center of the passing area (512).

Then, the passage area (384 ). Then, the passage area (256 in FIG. 11) is located at a position where the irradiation position is relatively shifted from the starting point by, for example, 0.5 beam size + margin in the +x direction and 1.5 beam size + margin in the +y direction. Set.

Then, from the starting point, for example, the passing area (384' ). Then, from the starting point, for example, the passing area (256 ').

Then, the passage area (384 ”).Then, the irradiation position is set relative to the starting point by, for example, 0.5 beam size + margin in the +x direction and 1.5 beam size + margin in the -y direction. 11 passing areas (256”) are set.

Referring to the relational table in FIG. 12, for each passage hole formed in the limiting aperture array substrate 212 for the beams of

sub-regions

1, 5, 21, and 25, the positions (starting points) (passing points) arranged at the beam pitch Only the region (512)) is formed in a shape that allows the beam to pass through. In the example of FIG. 13A, the passage hole is formed into a square whose side is twice the size of (1 beam size + margin).

sub-regions

2, 4, 22, and 24, the positions (starting points) (passing points) arranged at the beam pitch area (512)) and a position where the irradiation position is relatively shifted from the origin by, for example, 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the +y direction (passing area ( 384')) is formed into a shape through which the beam can pass. In the example of FIG. 13B, the passage hole is a square whose side is twice the size of (1 beam size + margin), and the upper half of the right side of the square has a side of the size (1 beam size + margin). It is formed in the shape of connected squares.

Referring to the relational table in FIG. 12, for each passing hole formed in the limiting aperture array substrate 212 for the beams of

sub-regions

3 and 23, the positions (starting points) arranged at the beam pitch (passing area (512) ) and a position where the irradiation position is relatively shifted from the origin by, for example, 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the +y direction (passing area (384')) and a position where the irradiation position is relatively shifted from the starting point by, for example, 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the -y direction (passing area (256')) It is formed into a shape that allows the beam to pass through. In the examples of FIGS. 13A to 13C, although not shown, the passage hole has a size three times (1 beam size + margin) in the x direction and a size twice (1 beam size + margin) in the y direction. Formed into a rectangle of size.

sub-regions

6, 10, 16, and 20, the positions (starting points) (passing points) arranged at the beam pitch area (512)), and a position (passing area (384")) is formed into a shape that allows the beam to pass through. In the examples of FIGS. 13A to 13C, although not shown, the passage hole has a size twice as large as (1 beam size + margin). It is formed in a shape in which a square whose sides are connected and a square whose side is the size of (1 beam size + margin) are connected to the left half of the lower side of the square.

Referring to the relationship table in FIG. 12, for each passing hole formed in the limiting aperture array substrate 212 for the beams of

sub-regions

7, 9, 17, and 19, the positions (starting points) (passing points) arranged at the beam pitch area (512)), and a position (passing area (384)) and a position where the irradiation position is relatively shifted from the origin by, for example, 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the +y direction (passing area (384) ')) and a position where the irradiation position is relatively shifted from the origin by, for example, 0.5 beam size + margin in the -x direction and 1.5 beam size + margin in the -y direction (passing area ( 384")), the beam is formed into a shape that allows the beam to pass through. In the examples of FIGS. 13A to 13C, although not shown, the passage hole has one side that is twice the size of (1 beam size + margin). A square with one side having a size of (1 beam size + margin) is formed in a shape in which the left half of the top side of the square, the top half of the right side, and the left half of the bottom side of the square are connected to each other.

Referring to the relational table in FIG. 12, for each passage hole formed in the limiting aperture array substrate 212 for the beams of sub-regions 8 and 18, the positions (starting points) arranged at the beam pitch (passing area (512) ) and a position where the irradiation position is relatively shifted from the origin by, for example, 0.5 beam size + margin in the -x direction and 1.5 beam size + margin in the +y direction (passing area (384)) Then, the irradiation position is relatively shifted from the starting point by, for example, 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the +y direction (passing area (384')). , the irradiation position is relatively shifted from the starting point by, for example, 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the -y direction (passing area (256')). , a position where the irradiation position is relatively shifted from the starting point by, for example, 0.5 beam size + margin in the -x direction and 1.5 beam size + margin in the -y direction (passing area (384")) In the examples shown in FIGS. 13A to 13C, although not shown, the passage hole is formed into a square whose side is twice the size of (1 beam size + margin). Squares each having a side of the size (1 beam size + margin) are connected to the left half of the top side of the square, the top half of the right side, the bottom half of the right side, and the left half of the bottom side.

Referring to the relational table in FIG. 12, for each passing hole formed in the limiting aperture array substrate 212 for the beams of the sub-regions 11 and 15, the positions (starting points) arranged at the beam pitch (passing area (512) ) and a position where the irradiation position is relatively shifted from the origin by, for example, 0.5 beam size + margin in the -x direction and 1.5 beam size + margin in the -y direction (passing area (384" )) and a position where the irradiation position is relatively shifted from the origin by, for example, 0.5 beam size + margin in the +x direction and 1.5 beam size + margin in the -y direction (passing area (256" )) is formed into a shape through which the beam can pass. In the examples of FIGS. 13A to 13C, although not shown, the passage holes are located in a square whose side is twice the size of (1 beam size + margin), the left half of the lower side of such a square, and the right half of the lower side. A shape is formed in which squares each having a side having a size of (1 beam size + margin) are connected.

Referring to the relational table in FIG. 12, for each passing hole formed in the limiting aperture array substrate 212 for the beams of the sub-regions 12 and 14, the positions (starting points) arranged at the beam pitch (passing area (512) ) and a position where the irradiation position is relatively shifted from the origin by, for example, 0.5 beam size + margin in the -x direction and 1.5 beam size + margin in the +y direction (passing area (384)) Then, the irradiation position is relatively shifted from the starting point by, for example, 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the +y direction (passing area (384')). , a position where the irradiation position is relatively shifted from the starting point by, for example, 0.5 beam size + margin in the -x direction and 1.5 beam size + margin in the -y direction (passing area (384")) Then, the irradiation position is relatively shifted from the starting point by, for example, 0.5 beam size + margin in the +x direction and 1.5 beam size + margin in the -y direction (passing area (256")) It is formed into a shape that allows the beam to pass through. In the examples of FIGS. 13A to 13C, although not shown, the passage hole is a square whose side is twice the size of (1 beam size + margin), the left half of the top side of the square, the top half of the right side, and the bottom side. The left half of the square and the right half of the lower side are formed into a shape in which squares each having one side of the size (1 beam size + margin) are connected.

Referring to the relational table in FIG. 12, for each passing hole formed in the limiting aperture array substrate 212 for the beam of sub-region #13, the positions (starting points) arranged at the beam pitch (passing area (512)) Then, the irradiation position is relatively shifted from the starting point by, for example, 0.5 beam size + margin in the -x direction and 1.5 beam size + margin in the +y direction (passing area (384)). , for example, a position where the irradiation position is relatively shifted by 0.5 beam size + margin in the +x direction and 1.5 beam size + margin in the +y direction (passing area (256)) and the starting point. For example, the position where the irradiation position is relatively shifted by 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the +y direction (passing area (384')) and from the origin , for example, the position where the irradiation position is relatively shifted by 1.5 beam size + margin in the +x direction and 0.5 beam size + margin in the -y direction (passing area (256')) and from the starting point. , for example, the position where the irradiation position is relatively shifted by 0.5 beam size + margin in the -x direction and 1.5 beam size + margin in the -y direction (passing area (384")) and the starting point. For example, at a position (passage area (256")) where the irradiation position is relatively shifted by 0.5 beam size + margin in the +x direction and 1.5 beam size + margin in the -y direction, It is formed into a shape that allows the beam to pass through. In the example of FIG. 13C, the passage hole is a square whose side is twice the size of (1 beam size + margin), the left half of the top side of the square, the right half of the top side, the upper half of the right side, and the bottom of the right side. A square whose side is (1 beam size + margin) is connected to each half, the left half of the lower side, and the right half of the lower side.

As described above, in the examples shown in FIGS. 13A to 13C, by moving the limiting aperture array substrate 212 (or shaping aperture array substrate 203) in the x and y directions, the beam array passing through the limiting aperture array substrate 212 is 512 beam array, 384 x 384 beam array in the center in x, y direction, 256 x 256 beam array in the center in x, y direction, 384 x 512 beam array in the center in x direction A book beam array, a 256 x 512 beam array at the center in the x direction, a 512 x 384 beam array at the center in the y direction, and a 512 x 256 beam array at the center in the y direction. , you can select any one of the seven groups.

As described above, among the multi-beam arrays (multi-beams 20), the beam array (multi-beams 20) that has passed through the limiting aperture array substrate 212 whose relative position to the multi-beam array is set at a predetermined position by movement, is irradiated. In other words, the beam array (multi-beam 20), the sample 101 is irradiated by an electron optical system such as a blanking aperture array mechanism 204, a reduction lens 205, a limiting aperture substrate 206, an objective lens 207, a main deflector 208, and a sub-deflector 209. First, the beam array (multi-beam 20) that has passed through the limiting aperture array substrate 212 advances to the blanking aperture array mechanism 204. The multi-beams 20 that have passed through the limited aperture array substrate 212 pass through corresponding blankers (first deflectors: individual blanking mechanisms 47 ) of the blanking aperture array mechanism 204 . Each of these blankers performs blanking control on the beam passing through the blanker so that the beam is in an ON state for a set drawing time (irradiation time).

FIG. 14 is a conceptual top view showing a part of the configuration within the membrane region of the blanking aperture array mechanism in the first embodiment. The blanking aperture array mechanism 204 has passage holes 25 (openings) for each of the multi-beams to pass through, at positions corresponding to the passage holes of the limiting aperture array substrate 212, in a membrane region made thin in the center of the substrate. will be provided. For example, the passage holes 25 are provided in accordance with the positions (starting points) arranged at the beam pitch. A set of a control electrode 24 and a counter electrode 26 (blanker: blanking deflector) is arranged at a position facing each other across the corresponding passage hole 25 among the plurality of passage holes 25. Furthermore, a control circuit 41 (logic circuit; cell) that applies a deflection voltage to the control electrode 24 for each passage hole 25 is arranged inside the blanking aperture array substrate 31 near each passage hole 25 . The counter electrode 26 for each beam is connected to ground. Each beam is subjected to blanking control by switching the control potential applied to the control electrode 24 from the control circuit 41.

The multi-beam 20 that has passed through the blanking aperture array mechanism 204 is reduced by a reduction lens 205 and proceeds toward a central hole formed in a limiting aperture substrate 206. Here, the electron beam deflected by the potential difference between the control potential applied to the control electrode 24 in the blanker of the blanking aperture array mechanism 204 and the ground potential of the counter electrode 26 is deflected from the hole in the center of the limiting aperture substrate 206. off, and is shielded by the limiting aperture substrate 206. On the other hand, the electron beam that is not deflected by the blanker of the blanking aperture array mechanism 204 passes through the central hole of the limiting aperture substrate 206, as shown in FIG. In this way, the limited aperture substrate 206 blocks each beam that is deflected by the individual blanking mechanism 47 into a beam OFF state. Then, each beam of one shot is formed by the beam that has passed through the limiting aperture substrate 206 and is formed from when the beam is turned on until when the beam is turned off. The multi-beam 20 that has passed through the limited aperture substrate 206 is focused by an objective lens 207 to become a pattern image with a desired reduction ratio, and the multi-beam 20 that has passed through the limited aperture substrate 206 is focused by a main deflector 208 and a sub-deflector 209. The entire beam is collectively deflected in the same direction, and each beam is applied to each irradiation position on the sample 101. Then, in each shot, the entire multi-beam 20 is further deflected by the main deflector 208 or the sub-deflector 209 by the shift amount (Dx, Dy) of the shot. The multi-beams 20 irradiated at once are ideally arranged at a pitch equal to the arrangement pitch of the plurality of apertures 22 of the shaped aperture array substrate 203 multiplied by the desired reduction ratio described above.

FIG. 15 is a conceptual diagram for explaining an example of a region to be drawn in the first embodiment. As shown in FIG. 15, the drawing area 30 of the sample 101 is virtually divided into a plurality of striped areas 32 having a predetermined width in the y direction, for example. The drawing area 30 corresponds to a chip area defined in the chip data. When drawing a pattern in the drawing area 30 with the drawing apparatus 100, for example, first, the XY stage 105 is moved and the multi-beam 20 is placed once at the left end of the first stripe area 32 or further to the left. Adjustment is made so that the irradiation area 34 that can be irradiated with the shot is located, and drawing is started. When writing the first stripe area 32, the XY stage 105 is moved, for example, in the -x direction, thereby relatively progressing the writing in the x direction. The XY stage 105 is continuously moved, for example, at a constant speed. After drawing the first stripe area 32, the stage position is moved in the -y direction, and the XY stage 105 is then moved, for example, in the x direction to perform drawing in the same way in the -x direction. . This operation is repeated to sequentially draw each stripe area 32. Drawing time can be shortened by drawing while changing the direction alternately. However, the drawing is not limited to such a case where the drawing is performed while changing the direction alternately, but when drawing each stripe area 32, the drawing may proceed in the same direction. In one shot, by the multi-beams formed by passing through each opening 22 of the shaped aperture array substrate 203, a plurality of shot patterns, the maximum number of which is the same as each opening 22, are formed at once.

FIG. 16 is a diagram showing an example of a multi-beam irradiation area and drawing target pixels in the first embodiment. In FIG. 16, the stripe area 32 is divided into a plurality of mesh areas based on the beam size of the multi-beam 20, for example. Each such mesh area becomes a pixel 36 (unit irradiation area, irradiation position, or drawing position) to be drawn. The size of the drawing target pixel 36 is not limited to the beam size, and may be configured to have any size regardless of the beam size. For example, the beam size may be 1/n (n is an integer of 1 or more) of the beam size. In the example of FIG. 12, the drawing area of the sample 101 has a plurality of stripe areas 32 in the y direction with substantially the same width as the size of the irradiation area 34 (drawing field) that can be irradiated with one multi-beam 20 irradiation. This shows the case where it is divided into . The size of the rectangular irradiation area 34 in the x direction can be defined as the number of beams in the x direction x the pitch between beams in the x direction. The size of the rectangular irradiation area 34 in the y direction can be defined as the number of beams in the y direction x the pitch between beams in the y direction. In the example of FIG. 16, for example, 512×512 columns of multibeams are abbreviated to 8×8 columns of multibeams. In the irradiation area 34, a plurality of pixels 28 (beam drawing positions) that can be irradiated with one shot of the multi-beam 20 are shown. The pitch between adjacent pixels 28 becomes the pitch between each beam of the multi-beam on the surface of the sample 101. One sub-irradiation area 29 (pitch cell) is composed of a rectangular area surrounded by the size of the beam pitch in the x and y directions. In the example of FIG. 16, each sub-irradiation area 29 is composed of, for example, 4×4 pixels. A drawing sequence is set in each sub-irradiation area 29 so that all pixels 36 in each sub-irradiation area 29 can be drawn by being irradiated with a plurality of beams.

Next, the main steps of the drawing method in Embodiment 1 will be explained.

The mode selection unit 66 selects one from a plurality of drawing modes. In each writing mode, a beam array used for writing is set. Each drawing mode has a different group, for example, from the three groups of 512 x 512 beam arrays, 384 x 384 beam arrays, and 256 x 256 beam arrays shown in the example of Fig. 5. One is set. The writing mode in which a 512×512 beam array is set is a high-speed writing mode that emphasizes throughput. The writing mode in which a 256×256 beam array is set is a high-precision writing mode that emphasizes writing accuracy. A writing mode in which a 384×384 beam array is set is an intermediate writing mode between these, for example. A user selects a drawing mode to be used for drawing processing of the chip from among a plurality of drawing modes prepared in advance using an interface (not shown) such as a GUI (graphic user interface). Alternatively, the drawing mode used for chip data or drawing parameter data stored in the storage device 140 may be defined. In addition, when performing the variable shaping shown in FIG. 4B, a variable shaping drawing mode is further added. The drawing mode can be changed for each board, so all chips on the same board can be set to the same drawing mode, or different drawing modes can be set for each chip or region on the same board. You can do it like this.

Alternatively, by further subdividing the plurality of writing modes, each writing mode may include, for example, a 512 x 512 beam array, a 448 x 448 beam array, or a 384 x 384 beam array as shown in the example of FIG. , a 256×256 beam array, and a 128×128 beam array, it is also preferable that one group is set differently from the others.

Alternatively, each drawing mode may include, for example, the 512 x 512 beam array (A) shown in the example of FIG. It is also preferable that one of the four groups of beam array (B), 512 x 384 beam array (C), and 384 x 512 beam array (D) is set. be.

Alternatively, the plurality of drawing modes may be further subdivided, and each drawing mode may have, for example, 512 x 512 beams as shown in the example of FIG. array, 384 x 384 beam array, 256 x 256 beam array, 384 x 512 beam array, 256 x 512 beam array, 512 x 384 beam array, and 512 x 256 beam array It is also preferable that one of the seven groups is set, which is different from the others.

Under the control of the drawing control unit 80, the aperture array control circuit 131 controls the drive circuit 214. The drive circuit 214 moves the shaped aperture array substrate 203 and the limiting aperture array substrate 212 in a direction perpendicular to the orbit center axis of the multi-beam 20 so that the relative positions of the shaped aperture array substrate 203 and the limiting aperture array substrate 214 change. move at least one of the Here, the drive circuit 214 moves at least one of the shaping aperture array substrate 203 and the limiting aperture array substrate 212 so that the beam array set to the selected writing mode passes through the limiting aperture array substrate 212. For example, the restricted aperture array substrate 212 is moved. Thereby, writing can be performed using a beam array whose current amount is limited according to the selected writing mode.

The shot data generation unit 62 reads chip data (drawing data) from the storage device 140 and generates irradiation time data (shot data) for each pixel 36. It is preferable that the irradiation time is determined by taking into consideration the pattern density drawn within the pixel and/or the proximity effect. These calculation methods may be the same as conventional methods.

The data processing unit 64 rearranges the obtained irradiation time data in the order of shots. The order of shots is determined by the drawing sequence controlled by the drawing control unit 80. The obtained irradiation time data is stored in the storage device 142.

The transfer control unit 79 transfers the irradiation time data to the deflection control circuit 130 in shot order. The deflection control circuit 130 then controls the

DAC amplifier units

132 and 134 and the blanking aperture array mechanism 204 according to the shot. The drawing mechanism 150 irradiates the sample 101 with a beam array that has passed through the limiting aperture array substrate 212 according to the relative position of the moving shaped aperture array substrate 203 and the limiting aperture array substrate 212 .

In the drawing sequence controlled by the drawing control unit 80, for example, when the XY stage 105 is continuously moving, tracking control is performed by the main deflector 208 so that the beam irradiation position follows the movement of the XY stage 105. be exposed. Each sub-irradiation area 29 is deflected so that all pixels 36 within its own sub-irradiation area 29 can be irradiated with a plurality of preset beams. For example, when each sub-irradiation area 29 is composed of 4×4 pixels 36 and all pixels are irradiated with any of the four beams, one-time tracking control will cause 1/4 of each sub-irradiation area 29 to be pixels (4 pixels) are drawn using, for example, 4 shots using one beam. By alternating the beams to be irradiated in each tracking control, all 4×4 pixels 36 can be irradiated in four tracking controls.

As described above, according to Embodiment 1, multi-beam irradiation can be performed in which the large current amount mode and the small current amount mode can be selectively switched.

[Embodiment 2]
In the first embodiment, a configuration in which the same number of passage holes as the number of beams of the multi-beam 20 are formed in the limited aperture array substrate 212 has been described, but the present invention is not limited to this. In the second embodiment, a configuration will be described in which a number of passing holes different from the number of beams of the multi-beam 20 are formed in the limited aperture array substrate 212. The configuration of the drawing apparatus 100 in the second embodiment is the same as that in FIG. 1. Hereinafter, the contents other than those specifically explained are the same as those in the first embodiment.

FIG. 17 is a conceptual diagram showing the configuration of a limited aperture array substrate in the second embodiment. In FIG. 17, the limited aperture array substrate 212 has a large passage hole 19 through which some of the multi-beams 20 can pass the entire beam array, and a remaining beam group through which the remaining beam groups of the multi-beams 20 can pass. A plurality of (small) passage holes 21 of the same number as the number of (small) passage holes 21 are formed. The large passage hole 19 and the plurality of passage holes 21 are formed so that all beams can pass through them at each position (starting point) arranged at the beam pitch (Px, Py) of the multi-beam 20 on the limited aperture array substrate 212. Ru. In the example of FIG. 17, for example, the large passage hole 19 is formed so that the entire 4×5 beam array in the center of the 8×7 multi-beams can pass through. Further, a case is shown in which 36 (small) passage holes 21 are formed so that the remaining surrounding beams, for example, 36 beams, can pass through. Note that the molded aperture array substrate 203 is the same as that shown in FIG. As the basic shape of the plurality of passage holes 21, for example, a square having a size equal to one beam size plus a margin is used. On the other hand, the shape of the large passage hole 19 is determined by multiplying (1 beam size + margin) by the number of passing beams in the x direction, and then adding, for example, a size larger than (1 beam size + margin). A rectangle is used in which the x-direction size is the size of the rectangle, and the y-direction size is the product of (1 beam size + margin) by the number of passing beams in the y-direction. However, the size greater than the sum (1 beam size + margin) is set to be smaller than the gap between adjacent (small) passage holes 21 .

FIGS. 18A and 18B are diagrams for explaining the state of the multi-beam depending on the relative position of the shaping aperture array substrate and the limiting aperture array substrate in the second embodiment. In FIG. 18A, all the beams 13 of the multi-beam 20 that have passed through the plurality of openings 22 of the shaped aperture array substrate 203 pass through the large passage hole 19 and the plurality of passage holes 21 of the limited aperture array substrate 212. This shows the case where the area overlaps with the position of the area within. In the example of FIG. 18A, all beams 13 of multi-beam 20 are allowed to pass through restricted aperture array substrate 212. In other words, the sample 101 is irradiated with a beam array with a large amount of current.

In the example of FIG. 18B, the driving mechanism 214 moves at least one of the shaped aperture array substrate 203 and the limiting aperture array substrate 212, so that the limiting aperture array substrate 212 moves between the shaped aperture array substrate 203 and the limiting aperture array substrate 212. Depending on the relative position of the multi-beam 20, either the entire multi-beam 20 or a part of the beam array of the entire multi-beam 20 is selectively passed. The limiting aperture array substrate 212 allows the central beam array of the entire multi-beam 20 to pass, when such a part of the beam array passes. The example in FIG. 18B shows, for example, a case where the limited aperture array substrate 212 is shifted in the x direction by a larger amount than the beam size of the multi-beam 200. As a result, in the example of FIG. 18B, among the multi-beams 200 that have passed through the plurality of apertures 22 of the shaped aperture array substrate 203, the beam 13 corresponding to the large passage hole 19 of the limited aperture array substrate 212 passes through the large passage hole 19. Can pass. However, since the beam 13 corresponding to the square passage hole 21 is out of position from the passage hole 21, it is blocked by the limiting aperture array substrate 212. In the example of FIG. 18B, the central beam array of the multi-beams 200 can each pass through the large passage hole 19. However, the beam group at the periphery cannot pass through the passage hole 21 and is blocked. Thereby, the number of beams of the multi-beam 20 can be reduced. In the example of FIG. 18B, the 8x7 beam array can be limited to a 4x5 beam array. Therefore, the total amount of current flowing through the multi-beam 20 can be reduced. Furthermore, the central beam array can be selectively extracted.

As described above, according to the second embodiment, even when using the large passage hole 19, the multi-beam beam can selectively switch between the large current amount mode and the small current amount mode using the central beam array. Can be irradiated.

The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples.

Furthermore, when the drive mechanism 214 moves the shaping aperture array substrate 203 instead of the limiting aperture array substrate 212, the orbit center axis of the multi-beam 20 also moves in the same way. Therefore, it is preferable to arrange an alignment coil (not shown) to perform one or more stages of beam deflection to return the shifted orbit center axis to its original position. For example, it is preferable to arrange an alignment coil (not shown) between the limiting aperture array substrate 212 and the blanking aperture array mechanism 204 to restore the shifted trajectory center axis. Alternatively, the blanking aperture array mechanism 204 may be moved together with the molded aperture array substrate 203.

Furthermore, descriptions of parts not directly necessary for explaining the present invention, such as the device configuration and control method, have been omitted, but the necessary device configuration and control method can be selected and used as appropriate. For example, although the description of the control unit configuration for controlling the drawing apparatus 100 has been omitted, it goes without saying that the required control unit configuration can be appropriately selected and used.

In addition, all multi-charged particle beam lithography apparatuses and multi-charged particle beam lithography methods that include the elements of the present invention and whose designs can be modified as appropriate by those skilled in the art are included within the scope of the present invention.

One aspect of the present invention relates to a multi-charged particle beam irradiation device and a multi-charged particle beam irradiation method, and can be used, for example, as a method for selecting the amount of current of a beam array that irradiates a substrate in a multi-beam writing device.

10 Large passage hole 13 Beam 20 Multi-beam 22

Openings

21, 23 Passing hole 24 Control electrode 25 Passing hole 26 Opposing

electrodes

28, 36 Pixel 29 Sub-irradiation area 30 Drawing area 31 Beam array area 32 Stripe area 34 Irradiation area 41 Control circuit 47 Individual blanking mechanism 62 Shot data generation section 64 Data processing section 66 Mode selection section 79 Transfer control section 80 Drawing control section 100 Drawing device 101 Sample 102 Electronic lens barrel 103 Drawing chamber 105 XY stage 106 Faraday cup 110 Control computer 112 Memory 130 Deflection control circuit 131 Aperture

array control circuit

132, 134 DAC amplifier unit 136 Lens control circuit 138 Stage control mechanism 139 Stage

position measuring device

140, 142 Storage device 150 Drawing mechanism 160 Control system circuit 200 Electron beam 201 Electron gun 202 Illumination lens 203 Molded aperture array substrate 204 Blanking aperture array mechanism 205 Reducing lens 206 Limiting aperture substrate 207 Objective lens 208 Main deflector 209 Sub-deflector 210 Mirror 212 Limiting aperture array substrate 214 Drive circuit

Claims

a shaped aperture array substrate forming a multi-beam array of charged particle beams;
a limiting aperture array substrate in which a plurality of passage holes are formed through which at least a portion of each beam of the multi-beam array can pass, and a shape of some of the plurality of passage holes is different from that of other passage holes;
The shaping aperture array substrate, the limiting aperture array substrate, and the multi-beam array are arranged in a direction perpendicular to the orbit center axis of the multi-beams so that the relative positions of the multi-beam array and the limiting aperture array substrate change. a mechanism for moving at least one of the array;
an optical system that irradiates a sample with a beam array of the multi-beam array that has passed through the limited aperture array substrate whose relative position with respect to the multi-beam array is set to a predetermined position by the movement;
A multi-charged particle beam irradiation device characterized by comprising:
The limited aperture array substrate is formed with a large passage hole through which a part of the multi-beam array can pass, and a plurality of small passage holes through which beam arrays other than the part of the multi-beam array can pass. The multi-charged particle beam irradiation device according to claim 1, characterized in that:
2. The multi-beam array according to claim 1, wherein the limiting aperture array substrate selectively allows one of the multi-beam array and a portion of the multi-beam array to pass through by changing the relative position. Charged particle beam irradiation device.
The multi-charged particle beam irradiation device according to claim 1, wherein the plurality of passage holes are formed in the shape of any one of a plurality of groups of three or more shapes.
4. The multi-charged particle beam irradiation apparatus according to claim 3, wherein the limiting aperture array substrate allows a central beam array of the multi-beam array to pass through when passing a part of the multi-beam array. .
The multi-charged multi-charged substrate according to claim 1, wherein the limiting aperture array substrate variably shapes a portion of each beam of the multi-beam array when passing at least a portion of the multi-beam array. Particle beam irradiation device.
The multi-charged particle beam irradiation device according to claim 1, wherein the plurality of passage holes are formed by a combination of a rectangular shape and a shape different from the rectangular shape.
The multi-charged particle beam irradiation according to claim 1, wherein the plurality of passage holes are formed such that the area of the passage hole formed in the central part is larger than the area of the passage hole formed in the outer peripheral part. Device.
A multi-beam array is formed by a shaped aperture array in which a plurality of shaped openings are formed,
A plurality of passing holes are formed through which each beam of the multi-beam array can pass, and a relative position between the shaped aperture array substrate and a limiting aperture array substrate is formed such that the shapes of the plurality of passing holes vary from region to region. The multi-beam array and the limiting aperture are moved by moving at least one of the shaping aperture array substrate, the limiting aperture array substrate, and the multi-beam array in a direction perpendicular to the orbit center axis of the multi-beam. By varying the relative position with the array substrate,
Irradiating the sample with a beam array of the multi-beam array that has passed through the limited aperture array substrate whose relative position with respect to the multi-beam array has been set to a predetermined position by the movement;
A multi-charged particle beam irradiation method characterized by:
The limited aperture array substrate is formed with a large passage hole through which a part of the multi-beam array can pass, and a plurality of small passage holes through which a beam array other than the part of the multi-beam array can pass. 10. The multi-charged particle beam irradiation method according to claim 9.