Blanking aperture array system and multi-charged particle beam lithography apparatus

Abstract

To inhibit malfunction of a circuit element from being caused by scattered electrons or X-ray.SOLUTION: A blanking aperture array system comprises: a blanking aperture array substrate having a circuit unit including a blanker for performing blanking deflection of each beam of a multi-beam and a circuit element for applying voltage to the blanker; a radiation shield that covers the circuit unit; and a mounting substrate electrically connected to the circuit unit. A cell unit including the blanker is provided at the center of the blanking aperture array substrate and the circuit unit is arranged on the peripheral side of the cell unit. The radiation shield includes an inner shield arranged on the blanking aperture array substrate, an outer shield that is arranged on the mounting substrate and is arranged outside the inner shield; and a flexible shield arranged across one end surface of the inner shield and one end surface of the outer shield.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a blanking aperture array system and a multi-charged particle beam writing apparatus. [Background technology]

[0002] As semiconductor integrated circuits (LSIs) become increasingly integrated, the design dimensions of semiconductor devices (MOSFETs: metal-oxide semiconductor field-effect transistors) continue to shrink in accordance with Moore's Law. Lithography, which is responsible for this shrinking, is a crucial pattern-generating technology within the semiconductor manufacturing process. The mainstream method for forming the desired LSI circuit patterns on wafers is to use a reduction projection exposure system (MPE) to reduce and transfer a high-precision master pattern (called a mask, or, especially when used in steppers and scanners, a reticle) formed on a quartz substrate onto a resist (photosensitive resin) coated on the wafer. Currently, EUV scanners using extreme ultraviolet (EUV) light sources are also being adopted for the creation of cutting-edge fine patterns. EUV exposure uses an EUV mask, which is patterned on a quartz substrate with a multilayer EUV-reflecting film and an absorber layer formed on top of that. Both masks are manufactured using an electron beam lithography system, which utilizes electron beams for their inherently superior resolution.

[0003] A multi-beam lithography system can irradiate multiple beams at once compared to lithography using a single electron beam, significantly improving throughput. In a multi-beam lithography system using a blanking aperture array substrate, for example, an electron beam emitted from a single electron source is passed through a shaping aperture array substrate with multiple openings to form multiple beams (multiple electron beams). The multiple beams pass through corresponding blankers on the blanking aperture array substrate. The blanking aperture array substrate has electrode pairs (blankers) for individually deflecting the beams and apertures between them for passing the beams. By fixing one of the electrode pairs at ground potential and switching the other between ground and other potentials, blanking deflection of each passing electron beam is individually performed. The electron beam deflected by the blanker is blocked by the limiting aperture, while the undeflected electron beam is irradiated onto the sample. The blanking aperture array substrate is equipped with circuits for independently controlling the electrode potential of each blanker.

[0004] When an electron beam is irradiated onto a shaping aperture array substrate with apertures for forming multiple beams, bremsstrahlung X-rays are generated. Furthermore, when multiple beams are formed on the shaping aperture array substrate, some of the electron beams are scattered by the edges of the apertures, becoming scattered electrons. When these bremsstrahlung X-rays or scattered electrons are irradiated onto the blanking aperture array substrate, the electrical characteristics of the MOSFETs included in the circuit elements are degraded due to the total ionizing dose (TID) effect, potentially causing malfunctions of the circuit elements. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-104272 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-107393 [Patent Document 3] Japanese Patent Application Publication No. 11-317357 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a blanking aperture array system and a multi-charged particle beam lithography apparatus that suppress malfunction of circuit elements due to scattered electrons and bremsstrahlung X-rays. [Means for solving the problem]

[0007] a blanking aperture array substrate having a circuit section including a circuit element for applying a voltage to the blankers; a radiation shield disposed on the blanking aperture array substrate and covering the circuit section; and a mounting substrate electrically connected to the circuit section of the blanking aperture array substrate, wherein a cell section including the beam passage holes and the blankers is disposed in a central portion of the blanking aperture array substrate, and the circuit section is disposed closer to the periphery of the blanking aperture array substrate than the cell section. The radiation shield has an inner shield disposed on the blanking aperture array substrate, an outer shield disposed on the mounting substrate and disposed outside the inner shield, and a flexible shield disposed across one end surface of the inner shield and one end surface of the outer shield.

[0008] A multi-charged particle beam writing apparatus according to one aspect of the present invention includes a charged particle beam source that emits a charged particle beam; a shaping aperture array substrate that has a plurality of apertures formed therein and in which portions of the charged particle beam pass through the plurality of apertures from upstream to downstream to form a multi-charged particle beam; a blanking aperture array substrate that has a plurality of beam passing holes through which each beam of the multi-charged particle beam passes and in which blankers that perform blanking deflection of each beam are provided corresponding to each beam passing hole; an upper radiation shield disposed above the blanking aperture array substrate; a lower radiation shield disposed below the blanking aperture array substrate; and wiring disposed on the blanking aperture array substrate that generates a signal according to data transferred from an external device and a mounting substrate that applies a voltage to the blanker via a radiation shield; a cell portion including the beam passing hole and the blanker is provided in a central portion of the blanking aperture array substrate; a circuit portion including a circuit element that applies a voltage to the blanker is arranged closer to the peripheral edge of the blanking aperture array substrate than the cell portion and is electrically connected to the mounting substrate; the upper radiation shield covers an upper side of the circuit portion and is arranged on the upper surface of the blanking aperture array substrate; and the lower radiation shield covers a lower side of the circuit portion and has an inner shield arranged below the blanking aperture array substrate, an outer shield arranged below the mounting substrate and outside the inner shield, and a flexible shield arranged across a lower surface of the inner shield and a lower surface of the outer shield. [Effects of the Invention]

[0009] According to the present invention, it is possible to prevent circuit elements on a blanking aperture array substrate from malfunctioning due to scattered electrons or bremsstrahlung X-rays. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a multi-charged particle beam writing apparatus according to an embodiment of the present invention; [Figure 2]FIG. 2 is a plan view of a shaped aperture array substrate. [Figure 3] FIG. 2 is a plan view of a blanking aperture array substrate. [Figure 4] FIG. 2 is a cross-sectional view of a blanking aperture array substrate. [Figure 5] FIG. 1 is a schematic diagram of a blanking aperture array system. [Figure 6] FIG. 2 is a perspective view of the upper radiation shield as seen from below. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. [Figure 8] FIG. 4 is a cross-sectional view of a first shield member. [Figure 9] FIG. 2 is a plan view of a flexible shield. [Figure 10] 10 is a cross-sectional view taken along line XX in FIG. 9. [Figure 11] FIG. 10 is a schematic diagram of a blanking aperture array system when the mounting substrate is thick. [Figure 12] FIG. 10 is a schematic diagram of a blanking aperture array system when the mounting substrate is thin. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiment, 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 an ion beam or the like may also be used.

[0012] Fig. 1 is a schematic diagram of a drawing apparatus according to an embodiment. The drawing apparatus 100 shown in Fig. 1 is an example of a multi-charged particle beam drawing apparatus. The drawing apparatus 100 includes an electron optical column 102 and a drawing chamber 103. Inside the electron optical column 102, an electron source 111, an illumination lens 112, a shaping aperture array substrate 10, a blanking aperture array system 1, a reduction lens 115, a limiting aperture member 116, a projection lens 117, and a deflector 118 are arranged.

[0013] The blanking aperture array system 1 includes a blanking aperture array substrate 30, a mounting substrate 40, and a radiation shield 50. The blanking aperture array substrate 30, the mounting substrate 40, and the radiation shield 50 are integrated together.

[0014] The mounting substrate 40 and the radiation shield 50 have openings for the electron beams (multi-beams MB) to pass through. The detailed configuration of the blanking aperture array system 1 will be described later.

[0015] An XY stage 105 is placed in the patterning chamber 103. A sample 101, such as a mask blank coated with resist and on which nothing is yet to be patterned, which will be the target substrate during patterning, is placed on the XY stage 105. The sample 101 may be an exposure mask used in manufacturing a semiconductor device, or a semiconductor substrate (silicon wafer) on which the semiconductor device is manufactured.

[0016] As shown in Figure 2, the shaping aperture array substrate 10 has m columns x n rows (m, n ≥ 2) of apertures 12 formed at a predetermined arrangement pitch. Each aperture 12 is formed as a rectangle of the same dimensions. The shape of the apertures 12 may also be circular. When a portion of the electron beam B passes through each of these multiple apertures 12, a multi-beam MB including multiple individual beams is formed.

[0017] As shown in Figure 3, the blanking aperture array substrate 30 has passage holes 32 formed in alignment with the positions of the apertures 12 on the shaping aperture array substrate 10 so that individual beams of the multi-beam MB can pass through. A blanker 34 consisting of a pair of two electrodes is disposed in each passage hole 32. One of the electrodes of the blanker 34 is fixed at ground potential, and the other is switched to a potential different from ground potential. The individual beams passing through each passage hole 32 are deflected independently by the voltage (electric field) applied to the blanker 34.

[0018] In this way, the plurality of blankers 34 perform blanking deflection of the corresponding individual beams among the multi-beams MB that have passed through the plurality of apertures 12 of the shaping aperture array substrate 10 .

[0019] 3 and 4, a plurality of blankers 34 are provided in a cell section C at the center of a blanking aperture array substrate 30. The blanking aperture array substrate 30 is rectangular in plan view, and circuit sections 36 are provided on both sides of the cell section C in the longitudinal direction (first direction, left-right direction in the figure). The circuit sections 36 include an LSI circuit that controls the application of voltage to the blankers 34.

[0020] 5, the circuit section 36 arranged on the underside of the blanking aperture array substrate 30 has a MOSFET and the like, is connected to the mounting substrate 40 by wire bonding, generates a signal according to data transferred from the outside, and applies a voltage to the blanker 34 via wiring (not shown) arranged within the blanking aperture array substrate 30. The circuit section 36 is provided with input / output pads (not shown) to which wires are connected.

[0021] The blanking aperture array substrate 30 is disposed on the lower surface (rear surface side) of the mounting substrate 40, and the cell section C is aligned with the opening of the mounting substrate 40. In this embodiment, the upstream side in the traveling direction of the electron beams (multi-beams MB) is referred to as the upper surface side or upper side, and the downstream side in the traveling direction is referred to as the lower surface side or lower side.

[0022] Electron beam B emitted from electron source 111 (emitting section) illuminates the entire shaping aperture array substrate 10 almost perpendicularly via illumination lens 112. Electron beam B passes through multiple openings 12 in shaping aperture array substrate 10, thereby forming multiple electron beams (multi-beams MB). Multi-beams MB pass through corresponding passage holes 32 in cell section C of blanking aperture array substrate 30.

[0023] The multi-beams MB that have passed through the blanking aperture array substrate 30 are reduced in size by the reduction lens 115 and proceed toward the central opening of the limiting aperture member 116. Here, the individual beams that have been slightly deflected by the blanker 34 move away from the central opening of the limiting aperture member 116 and are blocked by the limiting aperture member 116. On the other hand, the individual beams that have not been deflected by the blanker 34 pass through the central opening of the limiting aperture member 116. Beam blanking control is performed by controlling the electric field by applying a voltage to the blanker 34, i.e., by turning it on and off, and the off / on state of the individual beams on the sample 101 is controlled.

[0024] In this way, the limiting aperture member 116 blocks the individual beams deflected to the beam-off state by the multiple blankers 34. The time from when the beam is turned on to when it is turned off corresponds to one exposure time by irradiating the resist on the sample 101 with the beam.

[0025] The multi-beams MB that have passed through the limiting aperture member 116 are focused on the sample 101 by the projection lens 117, and the shape of the openings 12 in the shaping aperture array substrate 10 (image of the object plane) is projected onto the sample 101 (image plane) at a desired reduction ratio. The entire multi-beams are deflected in the same direction by the deflector 118, and each beam is irradiated onto its respective irradiation position on the sample 101. When the XY stage 105 is moving continuously, the deflector 118 controls the beam irradiation positions to follow the movement of the XY stage 105.

[0026] When the shaping aperture array substrate 10 forms the multibeams MB, a portion of the electron beam B strikes the shaping aperture array substrate 10, generating X-rays. Furthermore, when a portion of the electron beam B is scattered by the edge of the aperture 12, or when a portion of the electron beam B is reflected by the sidewall of the aperture 12, and the scattered electrons strike the blanking aperture array substrate 30 or other components in the drawing apparatus, X-rays are generated from the locations where the electrons strike. When such X-rays are irradiated onto the circuit section 36 of the blanking aperture array substrate 30, the electrical characteristics of the transistors deteriorate due to the TID effect, potentially resulting in malfunction.

[0027] Therefore, in this embodiment, the circuit section 36 of the blanking aperture array substrate 30 is covered with a radiation shield 50 made of a material with high X-ray absorption to suppress the effects of X-rays. The higher the atomic number of the radiation shield 50, the higher the X-ray absorption rate. Therefore, the radiation shield 50 is preferably made of a heavy metal such as tungsten, gold, tantalum, or lead. The radiation shield 50 preferably has a thickness that attenuates the X-rays generated in the drawing apparatus to approximately 1 / 1000 to 1 / 10,000 or less.

[0028] As shown in FIG. 5, the radiation shield 50 has an upper radiation shield 51 arranged on the upper surface side of the blanking aperture array substrate 30 and a lower radiation shield 52 arranged on the lower surface side of the blanking aperture array substrate 30.

[0029] 6 and 7, the upper radiation shield 51 has a rectangular cylindrical portion 51a and a protruding portion 51b that protrudes in the radial direction (outward) from the upper end of the cylindrical portion 51a. The protruding portion 51b is generally rectangular in plan view and is parallel to the upper surface of the blanking aperture array substrate 30. The upper surface of the blanking aperture array substrate 30 and the lower surface (bottom surface) of the cylindrical portion 51a are bonded together with a conductive adhesive such as silver paste. The cell portion C of the blanking aperture array substrate 30 is aligned so as to be located inside the inner circumferential surface 51c of the cylindrical portion 51a.

[0030] The cylindrical portion 51b of the upper radiation shield 51 is placed inside the opening of the mounting substrate 40, and the lower surface of the protruding portion 51b is bonded to the upper surface of the mounting substrate 40 with a conductive adhesive such as silver paste. For example, the upper radiation shield 51 may be made of tungsten with gold vapor-deposited on its surface.

[0031] As shown in FIG. 5, the lower radiation shield 52 includes an inner shield IS disposed below the blanking aperture array substrate 30, an outer shield OS disposed below the mounting substrate 40 and outside the inner shield IS, and a flexible shield 80 disposed across the lower surfaces of the inner shield IS and the outer shield OS. The inner shield IS and the outer shield OS are each composed of multiple members, at least some of which have the effect of preventing X-ray penetration. The inner shield IS includes a first shield member 60, a second shield member 62, and an inner mounting member 64. The outer shield OS includes an outer mounting member 70 and a third shield member 72.

[0032] 8, the first shielding member 60 has a rectangular cylindrical portion 60a and a peripheral wall portion 60b hanging down from the inner periphery of the lower surface (bottom surface) of the cylindrical portion 60a. The cylindrical portion 60a and the peripheral wall portion 60b have the same inner dimensions, and the inner periphery surface 60c of the first shielding member 60 is flush. The outer dimensions of the cylindrical portion 60a are larger than the outer dimensions of the peripheral wall portion 60b.

[0033] The lower surface of the blanking aperture array substrate 30 and the upper surface of the cylindrical portion 60a are bonded with a conductive adhesive such as silver paste. The cell portion C of the blanking aperture array substrate 30 is aligned so as to be located inside the inner peripheral surface 60c. For example, the first shield member 60 may be made of tungsten with gold vapor-deposited on its surface.

[0034] The second shield member 62 is a flat metal plate with an opening. This opening is, for example, rectangular and slightly larger than the outer dimensions of the peripheral wall portion 60b of the first shield member 60, with the peripheral wall portion 60b disposed within the opening. The first shield member 60 and the second shield member 62 are fixed together with screws. The peripheral edge of the opening on the upper surface of the second shield member 62 contacts and adheres tightly to the lower surface of the tubular portion 60b of the first shield member 60, which is located outside the peripheral wall portion 60b.

[0035] For example, the second shield member 62 may be made of tungsten with gold vapor-deposited on its surface. The thickness of the second shield member 62 is smaller than the height of the peripheral wall portion 60b of the first shield member 60, and the lower surface of the second shield member 62 is located higher than the lower surface of the peripheral wall portion 60b.

[0036] The outer mounting member 70 is a metal member located below the mounting substrate 40 and has an opening 70c. The first shield member 60, the second shield member 62, and the inner mounting member 64 are disposed within the opening 70c of the outer mounting member 70. The outer mounting member 70 is made of titanium, for example. The lower surface of the outer mounting member 70 is located lower than the lower surface of the second shield member 62. The outer mounting member 70 is fixed to other members of the imaging apparatus (for example, components located above the mounting substrate 40) using fastening members such as screws.

[0037] The third shielding member 72 is a flat metal plate having an opening 72c and is located below the outer mounting member 70. The third shielding member 72 is fixed to the outer mounting member 70 by screws. The outer peripheral region of the upper surface of the third shielding member 72 is in contact with and tightly adheres to the lower surface of the outer mounting member 70. The periphery of the opening 72c is located inside the outer peripheral edge of the second shielding member 62, and the outer peripheral portion of the second shielding member 62 and the inner peripheral portion of the third shielding member 72 overlap. For example, the third shielding member 72 may be made of tungsten with gold vapor-deposited on its surface.

[0038] The inner mounting member 64 is a rectangular cylindrical metal member, and its upper surface is adhered to the lower surface (bottom surface) of the peripheral wall portion 60b of the first shielding member 60 with a conductive adhesive such as silver paste. The inner peripheral surface 64c of the inner mounting member 64 and the inner peripheral surface 60c of the first shielding member 60 are flush with each other. The inner mounting member 64 is disposed within the opening 72c of the third shielding member 72. The lower surface of the inner mounting member 64 and the lower surface of the third shielding member 72 are located at approximately the same height.

[0039] 9 and 10, the flexible shield 80 is a flat metal thin plate with a rectangular opening 82 formed therein. The flexible shield 80 is the most downstream member of the components constituting the lower radiation shield 52. The dimensions of the opening 82 are slightly larger than the inner circumferential surface 60c of the first shield member 60. For example, the flexible shield 80 may be a flexible non-magnetic metal plate, and there are no limitations on its thickness or material; for example, an aluminum film with a thickness of approximately 0.1 mm on which gold is vapor-deposited can be used.

[0040] The flexible shield 80 is provided with a recess 81 (a downwardly protruding portion) that goes around the opening 82. The recess 81 can be formed, for example, by bending. While FIG. 10 shows an example in which the cross-sectional shape of the recess 81 is trapezoidal, other shapes such as a wave shape, semicircle, or triangle may be used, or the cross-sectional shape of the recess 81 may be an upwardly protruding shape. Furthermore, multiple recesses 81 may be provided concentrically in a plan view. By providing the recesses 81, the flexible shield 80 is made flexible.

[0041] The area of ​​the flexible shield 80 inside the recess 81 (between the recess 81 and the opening 82) is fixed to the inner mounting member 64 by screwing.

[0042] Additionally, the flexible shield 80 is fixed to the outer mounting member 70 together with the third shield member 72 in an area outside the recess 81 by screws.

[0043] The flexible shield 80 is disposed across the inner mounting member 64 and the third shield member 72 , and closes the gap between the outer peripheral edge of the inner mounting member 64 and the periphery of the opening 72 c of the third shield member 72 .

[0044] By providing the upper radiation shield 51, it is possible to prevent X-rays from entering from above the blanking aperture array substrate 30 and striking the circuit section .

[0045] Furthermore, the circuit section 36 of the blanking aperture array substrate 30 is covered from below by a lower radiation shield 52 consisting of a first shield member 60, a second shield member 62, an inner mounting member 64, an outer mounting member 70, a third shield member 72, and a flexible shield 80, and the first shield member 60, the second shield member 62, and the third shield member 72 prevent the intrusion of X-rays, and the flexible shield 80 prevents the intrusion of scattered electrons, thereby preventing X-rays and the like from hitting the circuit section 36. This prevents malfunction of the circuit elements of the circuit section 36 and extends the life of the blanking aperture array substrate 30.

[0046] Here, the thickness of the mounting board 40 varies depending on the production lot, and a mounting board 40 thicker than the desired thickness as shown in FIG. 11 may be mounted, or a thinner mounting board 40 as shown in FIG. 12 may be mounted.

[0047] If the thickness of the mounting board 40 changes, the heightwise positions of the outer mounting member 70 and the third shield member 72 change, and the positional relationship between the lower surface of the inner mounting member 64 and the lower surface of the third shield member 72 changes. In this embodiment, the flexible shield 80 that fills the gap between the periphery of the opening 72c of the third shield member 72 and the outer peripheral edge of the inner mounting member 64 is flexible, so even if a difference in heightwise position occurs between the lower surface of the inner mounting member 64 and the lower surface of the third shield member 72, the flexible shield 80 bends and plastically deforms (or elastically deforms) to accommodate the difference. Therefore, almost no pushing or pulling force is generated on the blanking aperture array substrate 30, and damage to the blanking aperture array substrate 30 can be suppressed.

[0048] Furthermore, even if X-rays from below pass through the flexible shield 80 and pass through the gap between the periphery of the opening 72c of the third shield member 72 and the outer peripheral edge of the inner mounting member 64, they are blocked by the second shield member 62 located above the gap, thereby preventing the X-rays from hitting the circuit section 36.

[0049] Furthermore, in this embodiment, the second shielding member 62 and the third shielding member 72 are separate bodies, which reduces the tensile load applied to the blanking aperture array substrate 30 compared to when they are integrated, thereby suppressing damage to the blanking aperture array substrate 30.

[0050] In the above embodiment, an example has been described in which the flexible shield 80 has a diaphragm structure, but it may have other shapes such as a bellows type.

[0051] In the above embodiment, a configuration has been described in which the blanking aperture array substrate 30 is disposed on the lower surface side of the mounting substrate 40, but the blanking aperture array substrate 30 may be disposed on the upper surface side of the mounting substrate 40 by inverting the configuration upside down. In this case, the configuration of the radiation shield 50 is also inverted upside down. That is, a radiation shield corresponding to the upper radiation shield 51 is disposed on the lower surface side of the blanking aperture array substrate 30, and a radiation shield corresponding to the lower radiation shield 52 is disposed on the upper surface side of the blanking aperture array substrate 30.

[0052] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be created by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0053] 10. Shaped aperture array substrate 30 Blanking aperture array substrate 34 Blanca 36 Circuit section 40 Mounting board 50 Radiation Shield 100 drawing device 101 Sample 102 Electron Optical Tube 103 Drawing room 111 Electron source

Claims

1. a blanking aperture array substrate having a plurality of beam passage holes formed therein through which each beam of the multi-charged particle beam passes, blankers for blanking deflection of each beam provided corresponding to each beam passage hole, and a circuit section including a circuit element for applying a voltage to the blankers; a radiation shield disposed on the blanking aperture array substrate and covering the circuit portion; a mounting substrate electrically connected to the circuit section of the blanking aperture array substrate; Equipped with a cell portion including the beam passing hole and the blanker is provided in a central portion of the blanking aperture array substrate, and the circuit portion is disposed closer to the periphery of the blanking aperture array substrate than the cell portion; a blanking aperture array system, wherein the radiation shield includes an inner shield disposed on the blanking aperture array substrate, an outer shield disposed on the mounting substrate and positioned outside the inner shield, and a flexible shield positioned across one end surface of the inner shield and one end surface of the outer shield.

2. the radiation shield includes an upper radiation shield that is disposed on the upper surface of the blanking aperture array substrate and covers an area above the circuit unit, and a lower radiation shield that is disposed below the blanking aperture array substrate and covers a area below the circuit unit, the lower radiation shield includes the inner shield disposed below the blanking aperture array substrate, and the outer shield disposed below the mounting substrate and outside the inner shield, 2. The blanking aperture array system of claim 1, wherein the flexible shield is disposed across a lower surface of the inner shield and a lower surface of the outer shield.

3. 3. The blanking aperture array system according to claim 2, wherein the flexible shield is flat, has an aperture formed therein for passing the multi-charged particle beams, and has a recess formed therein surrounding the aperture.

4. 4. The blanking aperture array system of claim 3, wherein the cross-sectional shape of the recess is trapezoidal or semicircular.

5. 4. The blanking aperture array system of claim 3, wherein the flexible shield has a plurality of the recesses arranged concentrically.

6. the upper radiation shield has a first cylindrical portion whose lower surface is in close contact with an upper surface of the blanking aperture array substrate, and a protruding portion that protrudes in a radially expanding direction from an upper end of the first cylindrical portion, the upper surface of the mounting substrate is in close contact with the lower surface of the protruding portion, 3. The blanking aperture array system according to claim 2, wherein the circuit section is connected to the mounting substrate by wire bonding.

7. The inner shield is a first shield member having a second cylindrical portion in close contact with a lower surface of the blanking aperture array substrate and a peripheral wall portion hanging down from the lower surface of the second cylindrical portion; a second shield member that is in close contact with a lower surface of the second cylindrical portion outside the peripheral wall portion; an inner mounting member that is in close contact with the lower surface of the peripheral wall portion, The outer shield is an outer mounting member located below the mounting board; a third shield member that is in close contact with the lower surface of the outer mounting member, 7. The blanking aperture array system of claim 6, wherein the flexible shield is disposed in close contact with and straddles a lower surface of the inner mounting member and a lower surface of the third shield member.

8. a charged particle beam source that emits a charged particle beam; a shaping aperture array substrate having a plurality of apertures formed therein, and a portion of the charged particle beam passing through each of the plurality of apertures from upstream to downstream to form a multi-charged particle beam; a blanking aperture array substrate having a plurality of beam passage holes formed therein through which each beam of the multi-charged particle beam passes, blankers for blanking deflection of each beam provided corresponding to each beam passage hole, and a circuit section including a circuit element for applying a voltage to the blankers; an upper radiation shield disposed on an upper surface of the blanking aperture array substrate and covering an upper portion of the circuit portion; a lower radiation shield disposed below the blanking aperture array substrate and covering a lower portion of the circuit unit; a mounting substrate electrically connected to the circuit section of the blanking aperture array substrate; Equipped with a cell portion including the beam passing hole and the blanker is provided in a central portion of the blanking aperture array substrate, and the circuit portion is disposed closer to the periphery of the blanking aperture array substrate than the cell portion; the lower radiation shield includes an inner shield arranged below the blanking aperture array substrate, an outer shield arranged below the mounting substrate and outside the inner shield, and a flexible shield arranged across a lower surface of the inner shield and a lower surface of the outer shield.

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