Multi-electron beam lithography apparatus and multi-electron beam lithography method

Abstract

PURPOSE: To provide a device for multi-electron beam drawing, capable of reducing a difference between regions of light-receiving quantities of each region of a photoelectric surface forming an electron beam.CONSTITUTION: A multi-electron beam drawing device includes: an array light source 201 which has a plurality of light sources and generates plural pieces of first light; a multi-lens array 212 which has a plurality of lenses, and divides the plural pieces of first light into plural pieces of second light by irradiating a part of the plurality of lenses out of the plurality of lenses with each first light of the plural pieces of first light, and irradiating at least a part of the lens out of the plurality of lenses with two or more pieces of first light out of the plural pieces of first light; a photoelectric surface 218 for making the plural pieces of second light incident from the surface, and discharging a multi-photoelectron beam from the rear face; a blanking aperture array mechanism 204 for performing individual blanking control of individually switching ON / OFF of each of the beams of the multi-photoelectron beam; and an electronic optical system (electron lens 207) for irradiating a sample with the multi-photoelectron beam.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to a multi-electron beam writing apparatus and a multi-electron beam writing method. [Background technology]

[0002] Lithography technology, which is responsible for the advancement of miniaturization of semiconductor devices, is the only extremely important process in semiconductor manufacturing that generates patterns. In recent years, with the increasing integration density of LSIs, the circuit line width required for semiconductor devices has been getting finer year by year. Here, electron beam (EB) lithography technology has inherently excellent resolution, and mask patterns are written onto mask blanks using an electron beam.

[0003] For example, there is a lithography system that uses multiple electron beams. Compared to lithography using a single electron beam, using multiple electron beams allows for the irradiation of many beams at once, thereby significantly improving throughput. In such a lithography system using the multi-electron beam method, for example, an electron beam emitted from an electron gun is passed through a shaping aperture array substrate with multiple holes to form multiple beams, each of which is blanked and each beam not blocked by the limiting aperture is reduced in size by an optical system, the mask image is reduced in size, and the beam is deflected by a deflector to be irradiated onto the desired position on the sample.

[0004] Here, as a technique for forming multiple electron beams, a method has been disclosed in which the entire surface of a photocathode is irradiated with a laser beam to emit electrons from multiple regions on the back surface of the photocathode, thereby forming multiple electron beams (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2003-511855 Summary of the Invention [Problem to be solved by the invention]

[0006] Although not publicly known, the use of multiple electron beams emitted from a photocathode in a drawing device is being considered. When using multiple electron beams emitted from a photocathode in a drawing device, it is necessary to improve the throughput of the drawing process, just as when using other electron emission sources. To achieve this, it is necessary to illuminate the photocathode with high intensity. Therefore, it is being considered to illuminate the photocathode with multiple lights from multiple light sources, rather than just one light from a single light source.

[0007] In order to uniformly control the intensity distribution of the multiple electron beams that are formed, it is necessary to uniformly receive the amount of illumination light irradiated on each region of the photocathode that forms the electron beam. However, the light from each light source has an intensity distribution. Generally, the intensity in the central region is higher than the intensity in the peripheral region. Therefore, to uniformly receive the amount of light in each region that forms the electron beam, it is ideal to arrange the light sources so that the number of light sources and the number of electron beams are 1:1.

[0008] However, it may be difficult to arrange the same number of light sources as the number of multi-electron beams due to problems such as space limitations and / or the influence of heat generated by each light source.

[0009] One aspect of the present invention provides an apparatus and method capable of improving the uniformity of the amount of light received in each region of a photocathode that forms electron beams in multi-electron beam writing. [Means for solving the problem]

[0010] A multi-electron beam lithography apparatus according to one aspect of the present invention includes: an array light source having a plurality of light sources and generating a plurality of first lights; a multi-lens array having a plurality of lenses, wherein each of the plurality of first light beams illuminates a part of the plurality of lenses, and at least a part of the plurality of lenses is irradiated with two or more of the first light beams, thereby dividing the plurality of first light beams into a plurality of second light beams; a photocathode that receives a plurality of second light beams from a front surface and emits multiple photoelectron beams from a rear surface; a blanking aperture array mechanism that performs individual blanking control to individually switch on / off each beam of the multi-photoelectron beam; an electron optical system that irradiates a sample with multiple photoelectron beams; The present invention is characterized by the following features.

[0011] Preferably, the plurality of lenses includes lenses of a plurality of sizes.

[0012] Also, the multi-lens array is referred to as a first multi-lens array, It is preferable to further include at least one second multi-lens array between the array light source and the first multi-lens array.

[0013] Preferably, the first multi-lens array and the second multi-lens array have different pitches for the lenses arranged therein.

[0014] It is also preferable to further provide a control circuit that links the timing of switching on / off the excitation light with the timing of switching on / off the beams of each beam for each shot of the multiple photoelectron beams.

[0015] A multi-electron beam writing method according to one aspect of the present invention includes: generating a plurality of first lights from an array light source having a plurality of light sources; a step of splitting the plurality of first lights into a plurality of second lights by using a multi-lens array having a plurality of lenses, with each of the plurality of first lights illuminating a part of the plurality of lenses, and at least a part of the plurality of lenses being irradiated with two or more of the first lights; a step of making a plurality of second light beams incident on a front surface of the photocathode and emitting multiple photoelectron beams from a rear surface of the photocathode; performing individual blanking control by using a blanking aperture array mechanism to individually switch on / off each beam of the multi-photoelectron beam; writing a pattern on a sample using multiple photoelectron beams; The present invention is characterized by the following features. [Effects of the Invention]

[0016] According to one aspect of the present invention, in multi-beam writing, it is possible to improve the uniformity of the amount of light received in each region of the photocathode that forms the electron beam. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a conceptual diagram showing a configuration of a drawing device according to a first embodiment. [Figure 2] 3 is a diagram showing an example of irradiation positions of a plurality of excitation lights that illuminate the multi-lens array in the first embodiment. FIG. [Figure 3] FIG. 3 is a diagram showing an example of the intensity distribution of excitation light in the first embodiment. [Figure 4] FIG. 2 is a conceptual diagram showing the configuration of a shaping aperture array substrate according to the first embodiment. [Figure 5] 2 is a cross-sectional view showing the configuration of a blanking aperture array mechanism in the first embodiment. FIG. [Figure 6] FIG. 2 is a conceptual diagram for explaining an example of a drawing operation in the first embodiment. [Figure 7] 3 is a diagram showing an example of a multi-beam irradiation area and a pixel to be written in the first embodiment. FIG. [Figure 8] FIG. 2 is a diagram for explaining an example of a multi-beam writing method according to the first embodiment. [Figure 9] 4 is a time chart showing an example of timing for switching on / off the generation of excitation light and timing for switching on / off a certain beam in the first embodiment. FIG. [Figure 10] FIG. 10 is a time chart showing an example of timing for switching on / off the generation of excitation light and timing for switching on / off a certain beam in the first modification of the first embodiment. [Figure 11] FIG. 10 is a time chart showing another example of the timing of switching between generation and stop of excitation light and the timing of switching ON / OFF of a certain beam in the first modification of the first embodiment. [Figure 12] FIG. 10 is a time chart showing another example of the timing of switching between generation and stop of excitation light and the timing of switching ON / OFF of a certain beam in the second modification of the first embodiment. [Figure 13] FIG. 10 is a time chart showing another example of the timing of switching between generation and stop of excitation light and the timing of switching ON / OFF of a certain beam in the third modification of the first embodiment. [Figure 14] 10 is a diagram showing an example of irradiation positions of a plurality of excitation lights that illuminate a multi-lens array in the second embodiment. FIG. [Figure 15] FIG. 11 is a diagram showing an example of irradiation positions of a plurality of excitation lights that illuminate a multi-lens array in the third embodiment. [Figure 16] FIG. 11 is a top view showing an example of arrangement of small individual lenses in the third embodiment. [Figure 17] FIG. 11 is a diagram showing an example of a histogram of light incident on a small-sized individual lens in the third embodiment. [Figure 18] 13 is a top view showing another example of arrangement of small-sized individual lenses in a comparative example of the third embodiment. FIG. [Figure 19] FIG. 13 is a diagram showing another example of a histogram of light incident on a small-sized individual lens in a comparative example of the third embodiment. [Figure 20] FIG. 11 is a top view showing another example of the arrangement of large individual lenses in the third embodiment. [Figure 21] FIG. 11 is a diagram showing another example of a histogram of light incident on a large individual lens in the third embodiment. [Figure 22] FIG. 11 is a diagram showing an example of irradiation positions of a plurality of excitation lights that illuminate a multi-lens array in a modification of the third embodiment. [Figure 23] FIG. 11 is a conceptual diagram showing the configuration of a drawing device according to a fourth embodiment. [Figure 24] FIG. 13 is a diagram showing an example of spot diameters of a plurality of excitation beams in the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Embodiment 1 FIG. 1 is a conceptual diagram showing the configuration of a lithography apparatus according to the first embodiment. In FIG. 1, the lithography apparatus 100 includes a lithography mechanism 150 and a control circuit 160. The lithography apparatus 100 is an example of a multi-charged particle beam lithography apparatus. In the lithography mechanism 150, an array light source 201, an illumination lens 202, a photoelectron emission mechanism 210, a multi-anode electrode 220, a shaping aperture array substrate 203, a blanking aperture array mechanism 204, an electron lens 205, a limiting aperture substrate 206, an electron lens 207 (objective lens), and an objective deflector 208 are arranged in this order within an electron lens column (multi-electron beam column) (not shown). An XY stage 105 is arranged within a lithography chamber (not shown) located below the electron lens column (not shown). A sample 101, such as a mask blank coated with resist and serving as a target substrate for lithography, is placed on the XY stage 105. The sample 101 may be an exposure mask for manufacturing a semiconductor device, a semiconductor substrate (silicon wafer), or the like. The electron lens barrel and the drawing chamber downstream of the photoelectron emission mechanism 210 are evacuated by a vacuum pump (not shown) and are controlled to a pressure lower than atmospheric pressure.

[0019] The array light source 201 has a plurality of light sources 11. Each light source 11 generates an excitation light. Therefore, the array light source 201 generates a plurality of excitation lights. In the example of FIG. 1, two light sources 11 are arranged in the x direction. Light sources arranged in the y direction are not shown. The number of light sources 11 is not limited to this. The array light source 201 is configured by arranging a plurality of light sources 11 in an array, the number of which is less than the number of multi-photoelectron beams described below. Each light source 11 can be, for example, a light-emitting diode (LED), a laser diode, or a mercury lamp.

[0020] In the photoelectron emission mechanism 210, a multi-lens array 212 is disposed on a glass substrate 214, and a multi-light-shielding film 216 serving as a light-shielding mask and a photocathode 218 (an example of a photoelectron emitter) are disposed on the back surface side of the glass substrate 214. The glass substrate 214 and the multi-lens array 212 may be formed integrally.

[0021] The control circuit 160 has an array drive circuit 112, a blanking aperture array (BAA) drive circuit 113, and an overall control circuit 161. The array drive circuit 112, the blanking aperture array (BAA) drive circuit 113, and the overall control circuit 161 are connected to one another by a bus (not shown).

[0022] 1 shows the configuration necessary for explaining the first embodiment. The drawing device 100 may also include other configurations that are normally required.

[0023] Next, the operation of the drawing mechanism 150 will be described. Under the control of an overall control circuit 161 that controls the entire drawing device 100, the array drive circuit 112 drives the array light source 201. The array light source 201 generates a plurality of excitation lights 200 (first lights). Each excitation light 200 includes continuous light or pulsed light. The array light source 201 generates a plurality of ultraviolet lights as the plurality of excitation lights 200. For example, it is preferable to use ultraviolet light or visible light with a wavelength of about 190 to 400 nm, for example, laser light with a wavelength of 266 nm.

[0024] The multiple excitation lights 200 generated from the array light source 201 are refracted by the illumination lens 202 and illuminate the multi-lens array 212. The illumination lens 202 may be omitted. The multi-lens array 212 further divides the multiple excitation lights 200 into multiple lights (second lights). The multi-lens array 212 has multiple individual lenses, and each excitation light of the multiple excitation lights illuminates a portion of the multiple individual lenses. At least some of the multiple individual lenses are irradiated with two or more excitation lights of the multiple excitation lights, thereby further dividing the multiple excitation lights 200 into multiple lights (second lights). Specifically, the multi-lens array 212 is configured as a lens array in which the same number of individual lenses as the multiple electron beams 20 or more are arranged in an array. For example, the multi-lens array 212 is configured with 512 × 512 lenses. The multi-lens array 212 focuses each of the divided multiple lights and adjusts the focal position of each light to the height position of the surface of the photocathode 218. By concentrating the light using the multi-lens array 212, the effective brightness of each light can be increased.

[0025] A plurality of openings are formed in the multi-light-shielding film 216 so that the irradiation spot area of ​​each of the plurality of light beams (multi-light beams) that have been split and concentrated is exposed. Although the multi-light-shielding film 216 may be omitted, the multi-light-shielding film 216 can block light that has passed through the glass substrate 214 without being concentrated by the multi-lens array 212 and / or scattered light in areas other than the openings. It is preferable to use a chromium (Cr) film, for example, as the multi-light-shielding film 216.

[0026] Each light beam passing through the multi-light-shielding film 216 is incident on the surface of the photocathode 218. The photocathode 218 receives multiple light beams from its front surface and emits multiple photoelectron beams 20 from its rear surface. For example, a 512 × 512 array of photoelectron beams is emitted in the x and y directions. Specifically, the photocathode 218 receives multiple light beams from its front surface and emits photoelectrons from positions on its rear surface corresponding to the incident positions. The photocathode 218 is preferably formed of a film primarily made of a platinum-based material such as platinum (Pt) or ruthenium (Ru). Furthermore, it is preferable that the rear surface side (downstream side in FIG. 1) of the Pt main film be coated with a carbon (C)-based material. Alternatively, a film containing an alkali metal such as cesium (Cs), rubidium (Rb), or potassium (K) may be used. When the surface of the photocathode 218 is irradiated with photons having an energy greater than the work function of the material of the photocathode 218, the photocathode 218 emits photoelectrons from the rear surface. In order to obtain a multi-photoelectron beam 20 with a sufficient current density for use in the inspection device 100, the surface of the photocathode 218 is irradiated with a current of, for example, 0.1 to 100,000 W / cm. 2 degree (10 3 ~10 9 W / m 2 It is preferable that light of about 1000 nm is incident.

[0027] The multi-photoelectron beams 20 emitted from the photocathode 218 are accelerated by being extracted by a multi-anode electrode 220 having a relatively positive potential applied thereto and having openings arranged at the same pitch as the irradiation spots of the multi-lens array 212, and travel toward the shaping aperture array substrate 203.

[0028] FIG. 2 is a diagram showing an example of irradiation positions of a plurality of excitation lights 50 that illuminate the multi-lens array in the first embodiment. FIG. 3 shows an example of the intensity distribution of excitation light 50 in the first embodiment. The example in FIG. 2 shows, for example, 7×5 individual lenses 14 among the multiple individual lenses 14 constituting the multi-lens array 212. The multiple individual lenses 14 are arranged in an array. As shown in FIG. 3, each excitation light 50 has an intensity distribution 12. As shown in FIG. 3, the intensity is high at the center and decreases toward the periphery. FIG. 3 shows a case where the beam width (half-width) at a position of, for example, half the value obtained by subtracting the minimum intensity from the maximum intensity in the intensity distribution is set to a spot diameter φD. The example in FIG. 2 shows each excitation light 50 with a spot diameter φD on the incident surface of the multi-lens array 212. The example in FIG. 2 shows a case where multiple excitation light 50 are arrayed in a square lattice pattern. For example, this can be achieved by arranging the light sources of the array light source 201 in a square lattice pattern.

[0029] Each of the multiple excitation lights 50 from the array light source 201 illuminates a portion of the multiple individual lenses 14 that make up the multi-lens array 212. Furthermore, at least a portion of the multiple individual lenses 14 that make up the multi-lens array 212 is irradiated with two or more excitation lights 50. In the example of Fig. 2, the multiple excitation lights 50 illuminate the multi-lens array 212 at a pitch P that is, for example, twice the arrangement pitch between the individual lenses 14. Each excitation light 50 illuminates the multiple individual lenses 14, for example, around the central individual lens 14 of the 3 x 3 individual lenses 14. In the example of FIG. 2, the spot diameter of each excitation light 50 includes, for example, the entire central individual lens 14 (lens 1), the entire two individual lenses 14 (lens 2) on either side of the central individual lens 14 in the x direction, and the entire two individual lenses 14 (lens 2) on either side of the central individual lens 14 in the y direction, as well as portions of each of the four individual lenses 14 (lens 3) diagonally positioned from the central individual lens 14. Since the individual lens 14 (lens 1) located at the center of the irradiation position of each excitation light 50 is irradiated with light of the maximum intensity, the amount of light received by the central individual lens 14 (lens 1) is large. In contrast, the intensity of the excitation light irradiated on the peripheral individual lenses 14 is lower than that of the center. Therefore, the amount of excitation light received by each peripheral individual lens 14 is small.

[0030] For this reason, in the first embodiment, the peripheral individual lenses 14 are illuminated with two or more excitation lights 50. In the example of FIG. 2, the two individual lenses 14 (lens 2) on either side of the central individual lens 14 (lens 1) in the x direction and the two individual lenses 14 (lens 2) on either side of the central individual lens 14 (lens 1) in the y direction are each illuminated with two excitation lights in an overlapping manner. The four individual lenses 14 (lens 3) diagonally adjacent to the central individual lens 14 (lens 1) are each illuminated with four excitation lights in an overlapping manner. The four individual lenses 14 (lens 2) on either side of the central individual lens 14 (lens 1) in the x direction and y direction are entirely illuminated with low-illuminance excitation lights. Therefore, by being illuminated with two low-illuminance excitation lights, the amount of light received by the central individual lens 14 (lens 1) can be made substantially the same as or approach the amount of light received by the central individual lens 14 (lens 1). The four individual lenses 14 (lens 3) in the diagonal direction are only partially included in the spot diameter of each excitation light 50, so by being irradiated with the four excitation lights, the amount of light received can be made approximately the same as or close to the amount of light received by the individual lens 14 (lens 1) located in the center.

[0031] Therefore, the amount of light received by the individual lens 14 (lens 1) located in the center and the individual lenses 14 (lens 2) (lens 3) located on the periphery can be made approximately uniform.

[0032] FIG. 4 is a conceptual diagram illustrating the configuration of the shaping aperture array substrate 203 according to the first embodiment. In FIG. 4 , holes (openings) 22 are formed in a matrix of p columns by q columns (p, q≧2) in the x and y directions at a predetermined pitch in the shaping aperture array substrate 203. In FIG. 4 , for example, 512 columns by 512 columns of holes 22 are formed in the x and y directions. The holes 22 are formed to match the trajectories of the multi-photoelectron beams 20 emitted from the photocathode 218. The photoelectron beams emitted from the photocathode 218 are not necessarily uniform in shape and size. For example, they may spread in the divergent direction. Therefore, the shape and size of each photoelectron beam are shaped by the shaping aperture array substrate 203. In FIG. 4 , the holes 22 are all formed as rectangles of the same shape. Alternatively, they may be circles of the same diameter. The shaping aperture array substrate 203 forms the multi-photoelectron beams 20 used for drawing. Specifically, the multiple photoelectron beams 20 are shaped into a desired shape and size by passing a portion of the emitted multiple photoelectron beams through each of these multiple holes 22. On the other hand, if the divergence of each photoelectron beam emitted from the photocathode 218 is small, the shaping aperture array substrate 203 can be omitted.

[0033] FIG. 5 is a cross-sectional view showing the configuration of the blanking aperture array mechanism according to the first embodiment. In the blanking aperture array mechanism 204, as shown in FIG. 5, a semiconductor substrate 31 made of silicon or the like is placed on a support base 33. The central portion of the substrate 31 is thinly shaved from, for example, the backside, to form a membrane region 330 (first region) with a thin film thickness h. The periphery surrounding the membrane region 330 is a peripheral region 332 (second region) with a thick film thickness H. The upper surfaces of the membrane region 330 and the peripheral region 332 are formed to be at the same height or substantially at the same height. The substrate 31 is held on the backside of the peripheral region 332 by the support base 33. The central portion of the support base 33 is open, and the membrane region 330 is located in the open region of the support base 33.

[0034] In the membrane region 330, passage holes 25 (openings) for passing through each beam of the multi-photoelectron beam 20 are opened at positions corresponding to the holes 22 of the shaping aperture array substrate 203 shown in FIG. 4. In other words, a plurality of passage holes 25 for passing through corresponding beams of the multi-photoelectron beam 20 using electron beams are formed in an array in the membrane region 330 of the substrate 31. A plurality of electrode pairs, each having two electrodes, are arranged on the membrane region 330 of the substrate 31 at positions facing each other across a corresponding passage hole 25 among the plurality of passage holes 25. Specifically, on the membrane region 330, as shown in FIG. 5, pairs of a control electrode 24 for blanking deflection and a counter electrode 26 (blankers: blanking deflectors) are arranged in positions near each passage hole 25 on either side of the corresponding passage hole 25. Furthermore, a logic circuit 41 for applying a deflection voltage to the control electrode 24 for each passage hole 25 is arranged inside the substrate 31 and near each passage hole 25 on the membrane region 330. The counter electrode 26 for each beam is connected to ground.

[0035] Each logic circuit 41 is connected to n-bit (e.g., 10-bit) parallel wiring for a control signal. In addition to the n-bit parallel wiring for the control signal, each logic circuit 41 is also connected to wiring for a clock signal line, a read signal, a shot signal, and a power supply. An individual blanking control mechanism is configured for each beam constituting the multi-beam, consisting of a control electrode 24, a counter electrode 26, and a logic circuit 41. The array-shaped logic circuits 41 formed in the membrane region 330 are grouped, for example, by the same row or the same column, and the logic circuits 41 within a group are connected in series. Signals from pads 43 arranged in each group are transmitted to the logic circuits 41 within the group. Specifically, a shift register (not shown) is arranged in each logic circuit 41, and, for example, the shift registers in the logic circuits 41 of beams in the same row among the p×q multi-beams are connected in series. Then, for example, control signals for beams in the same row of p×q multi-beams are transmitted in series, and the control signals for each beam are stored in the corresponding logic circuit 41 by p clock signals, for example.

[0036] An amplifier (an example of a switching circuit), not shown, is disposed within the logic circuit 41. The amplifier is connected to a positive potential (Vdd: blanking potential: first potential) (e.g., 5 V) (first potential) and a ground potential (GND: second potential). The amplifier's output line (OUT) is connected to a control electrode 24. On the other hand, the counter electrode 26 is applied with the ground potential. A plurality of control electrodes 24, to which the blanking potential and the ground potential are switchably applied, are disposed on the substrate 31 at positions facing the corresponding counter electrodes 26 of the plurality of counter electrodes 26, with the corresponding passing holes 25 sandwiched between them.

[0037] When an L potential is applied to the amplifier input (IN), the amplifier output (OUT) becomes a positive potential (Vdd), and the corresponding beam is deflected by an electric field due to the potential difference with the ground potential of the opposing electrode 26, and is controlled so that the beam is turned OFF by being blocked by the limiting aperture substrate 206. On the other hand, when an H potential is applied to the amplifier input (IN) (active state), the amplifier output (OUT) becomes a ground potential, and there is no potential difference with the ground potential of the opposing electrode 26, so the corresponding beam is not deflected, and the beam is controlled so that it is turned ON by passing through the limiting aperture substrate 206.

[0038] The blanking aperture array mechanism 204 performs individual blanking control, which individually switches each beam of the multi-photoelectron beam 20 ON / OFF by deflecting each beam. In individual blanking control, the electron beam 20 passing through each passage hole is deflected by voltages applied to two independent pairs of control electrodes 24 and counter electrodes 26, and blanking control is performed by this deflection. Specifically, the pairs of control electrodes 24 and counter electrodes 26 individually blank and deflect corresponding beams of the multi-photoelectron beam 20 by potentials switched by amplifiers serving as corresponding switching circuits. In this way, the multiple blankers perform blanking deflection of corresponding beams of the multi-photoelectron beam 20 that have passed through the multiple holes 22 (openings) in the shaping aperture array substrate 203.

[0039] The multi-photoelectron beams 20 that pass through the blanking aperture array mechanism 204 are reduced in size by the electron lens 205 and travel toward a central hole formed in a limiting aperture substrate 206 located near the crossover position. Here, electron beams of the multi-photoelectron beams 20 that are deflected by the blanker of the blanking aperture array mechanism 204 are displaced from the central hole of the limiting aperture substrate 206 and are blocked by the limiting aperture substrate 206 (beam OFF). On the other hand, electron beams that are not deflected by the blanker of the blanking aperture array mechanism 204 pass through the central hole of the limiting aperture substrate 206 as shown in FIG. 1 (beam ON). Blanking control is performed by turning on / off the individual blanking control mechanisms, and the ON / OFF of each beam is controlled. In this way, the limiting aperture substrate 206 forms a single shot of beams formed for each beam from when the beam is turned on until when the beam is turned off and has passed through the limiting aperture substrate 206. The sample 101 is irradiated with the multi-photoelectron beams 20, which are controlled to be beam-on by the electron optical system. Specifically, the multi-photoelectron beams 20 that have passed through the limiting aperture substrate 206 are focused by the electron lens 207 (objective lens) to form a pattern image with the desired reduction ratio. The entire multi-photoelectron beams 20, which are controlled to be beam-on, are deflected in the same direction by the objective deflector 208, and each beam is irradiated onto the respective irradiation positions on the sample 101. Ideally, the multi-photoelectron beams 20 irradiated at one time are arranged at a pitch obtained by multiplying the arrangement pitch of the multiple holes 22 in the shaping aperture array substrate 203 by the desired reduction ratio. The electron lenses 205 and 207 may be either electrostatic lenses or electromagnetic lenses.

[0040] FIG. 6 is a conceptual diagram illustrating an example of the writing operation in the first embodiment. As shown in FIG. 6, the writing region 30 on the sample 101 is virtually divided into a plurality of stripe regions 32, each having a predetermined width in the y direction. First, the XY stage 105 is moved to adjust the irradiation region 34 that can be irradiated with a single shot of the multi-photoelectron beam 20 to the left end of the first stripe region 32, or to a position further to the left, and writing begins. When writing the first stripe region 32, the XY stage 105 is moved, for example, in the −x direction to relatively write in the x direction. The XY stage 105 is moved continuously, for example, at a constant speed. After writing the first stripe region 32, the stage position is moved in the −y direction to adjust the irradiation region 34 to the right end of the second stripe region 32, or to a position further to the right, relative to the y direction. Then, the XY stage 105 is moved, for example, in the x direction to similarly write in the −x direction. The writing time can be reduced by alternately changing the direction of writing, such as writing in the x direction in the third stripe region 32 and writing in the -x direction in the fourth stripe region 32. However, writing is not limited to alternately changing the direction of writing, and writing in each stripe region 32 may proceed in the same direction. In one shot, multiple shot patterns, up to the same number as the number of holes 22 formed in the shaping aperture array substrate 203, are simultaneously formed by the multi-beams formed by passing through each hole 22 in the shaping aperture array substrate 203. Furthermore, multiple writing is also suitable for writing. When multiple writing is performed, the same stripe region 32 may be written multiple times without shifting the position, or the stripe region 32 for each pass may be set with a shift in position.

[0041] FIG. 7 is a diagram showing an example of a multi-beam irradiation region and a pixel to be written in the first embodiment. In FIG. 7 , a plurality of control grids 27 (design grids) are set in the stripe region 32, for example, arranged in a grid pattern at the beam pitch of the multi-photoelectron beams 20 on the surface of the sample 101. For example, an arrangement pitch of approximately 10 nm is preferable. These plurality of control grids 27 are the designed irradiation positions of the multi-photoelectron beams 20. The arrangement pitch of the control grids 27 is not limited to the beam size, and may be any size that can be controlled as a deflection position of the objective deflector 208 regardless of the beam size. Then, a plurality of pixels 36 are set, virtually divided into a mesh shape with the same size as the arrangement pitch of the control grids 27, with each control grid 27 at the center. Each pixel 36 is an irradiation unit region for one beam of the multi-photoelectron beams 20. The example of FIG. 7 shows a case where the writing area of ​​the sample 101 is divided, for example, in the y direction, into multiple stripe regions 32 with a width substantially equal to the size of the irradiation area 34 (writing field) that can be irradiated with one irradiation of the multi-photoelectron beam 20. The x-direction size of the irradiation area 34 can be defined as the value obtained by multiplying the inter-beam pitch of the multi-photoelectron beam 20 in the x direction (first direction) by the number of beams in the x direction. The y-direction size of the irradiation area 34 can be defined as the value obtained by multiplying the inter-beam pitch of the multi-photoelectron beam 20 in the y direction (second direction) by the number of beams in the y direction. Note that the width of the stripe regions 32 is not limited thereto. Preferably, the size is n times the size of the irradiation area 34 (n is an integer greater than or equal to 1). In the example of FIG. 7, for example, the illustration of the 512 × 512 arrays of the multi-photoelectron beam 20 is simplified to an 8 × 8 array of the multi-photoelectron beam. A plurality of pixels 28 (beam drawing positions) that can be irradiated with one shot of the multi-photoelectron beam 20 are shown within the irradiation area 34. In other words, the pitch between adjacent pixels 28 is the pitch between each of the designed multi-beams. In the example of FIG. 7, one sub-irradiation area 29 is formed by an area surrounded by the inter-beam pitch. In the example of FIG. 7, each sub-irradiation area 29 is formed by 4×4 pixels.

[0042] FIG. 8 is a diagram illustrating an example of a multi-beam writing method according to the first embodiment. FIG. 8 shows a portion of a sub-irradiation region 29 written by each beam. The example in FIG. 8 illustrates a case in which four pixels are written (exposed) while the XY stage 105 moves a distance equivalent to eight beam pitches. In each shot, each pixel is irradiated with a beam for a desired irradiation time controlled between 0 and the maximum irradiation time Ttr. The four pixels are written (exposed) during the time from t=0 to t=4Ttr. While the four pixels are written (exposed), the objective deflector 208 collectively deflects the entire multi-photoelectron beam 20, causing the irradiation region 34 to follow the movement of the XY stage 105 so that the relative position of the irradiation region 34 with respect to the sample 101 does not shift due to the movement of the XY stage 105. In other words, tracking control is performed. The example in Figure 8 shows a case where one tracking cycle is performed by drawing (exposing) four pixels while the sample 101 on the XY stage 105 continuously moves a distance of eight beam pitches. After the beam is irradiated to the four pixels, the beam deflection for tracking control is reset, returning the tracking position to the tracking start position where tracking control was initiated. In the example in Figure 8, at time t = 4Ttr, trunking of the target sub-irradiation area 29 is released, and the beam is redirected back to the target sub-irradiation area 29 shifted by eight beam pitches in the x direction. Note that while the example in Figure 8 describes beam (1) at coordinates (1, 3), similar drawing is performed on the corresponding sub-irradiation areas 29 for beams at other coordinates.

[0043] Since the first pixel row from the right in each sub-irradiation area 29 has been drawn, after a tracking reset, the deflector 209 first deflects the beams in the next tracking cycle to align (shift) the drawing positions of the beams corresponding to the bottom-most control grid 27 of the second pixel from the right in each sub-irradiation area 29. Repeating this operation completes beam irradiation of all pixels in each sub-irradiation area 29. Repeating this operation during drawing of the stripe area 32 sequentially shifts the positions of the irradiation areas 34a to 34o shown in FIG. 6, thereby drawing the stripe area. While the example in FIG. 8 illustrates a case in which the sub-irradiation area 29 is composed of a 4×4 pixel area, this is not limiting. If the sub-irradiation area 29 is composed of an n×n pixel area, n control grids (n pixels) are drawn by shifting the irradiation positions in one tracking operation. By drawing n pixels at a time with different beams in n tracking operations, all pixels in a single n×n pixel area are drawn.

[0044] In multi-beam lithography, the dose of each beam is controlled by its irradiation time. The irradiation time of each beam is controlled by the blanking aperture array mechanism 204. However, even when the blanking aperture array mechanism 204 controls the beam to be turned off, the limiting aperture 206 may not be able to completely block the beam, resulting in leakage beams. Leakage beams can expose the resist on the sample 101, adversely affecting lithography accuracy. Therefore, it is desirable to suppress or reduce leakage beams. Furthermore, with conventional electron beam sources, such as a thermal cathode electron gun, it is difficult to turn on / off the emission of a beam consisting of thermoelectrons during lithography. Therefore, even when the blanking aperture array mechanism 204 controls the beam to be turned off, leakage beams continue to be generated as long as the electron gun is emitting electron beams. Therefore, in the first embodiment, instead of an electron gun, an array light source 201 capable of high-speed ON / OFF response and a photocathode 218 that emits photoelectrons in response to incident excitation light are used.

[0045] The control circuit 160 then links the timing of switching the generation / stop of the excitation light with the timing of switching the beam ON / OFF of each beam for each shot of the multi-photoelectron beam 20. Specifically, as shown in FIG. 1 , the control circuit 160 links the array drive circuit 112 that drives the array light source 201 and the BAA drive circuit 113 that controls the blanking aperture array mechanism 204. At least one of the array drive circuit 112, the BAA drive circuit 113, and the overall control circuit 161 controls the array drive circuit 112 and the BAA drive circuit 113 to link them together. For example, the overall control circuit 161 controls the array drive circuit 112 and the BAA drive circuit 113 to link them together. Alternatively, the array drive circuit 112 may control itself to link itself with the BAA drive circuit 113. Alternatively, the BAA drive circuit 113 may control itself to link itself with the array drive circuit 112. A synchronization circuit including an oscillator that generates a clock signal for synchronization may be mounted in any of the array drive circuit 112, BAA drive circuit 113, and overall control circuit 161. Specific control contents will be explained below.

[0046] 9 is a time chart showing an example of the timing of switching the generation / stop of excitation light and the timing of switching the beam ON / OFF in embodiment 1. Fig. 9 shows an ON / OFF timing chart showing the generation / stop of excitation light, a timing chart of ON / OFF drive when performing individual blanking control of a beam of the blanking aperture array mechanism 204, and a timing chart of ON / OFF of the beam accompanying the individual blanking control. The example in Fig. 9 shows the k-th shot of the multi-photoelectron beam 20 and the k+1-th shot of the multi-photoelectron beam 20.

[0047] 9, the control circuit 160 controls each beam that is to be controlled to be beam-on to be switched from the beam-off state to the beam-on state after the excitation light 200 is switched from the stopped (OFF) state to the generated (ON) state for each shot of the multi-photoelectron beam 20. Then, the control circuit 160 controls the excitation light 200 to be switched from the generated state to the stopped state after all beams have been switched to the beam-off state. In the shot cycle of the multi-photoelectron beam 20, as described above, an arbitrary irradiation time within the preset maximum irradiation time Ttr is set for each beam.

[0048] Therefore, the array light source 201 starts generating each excitation light beam 200 at the shot cycle start timing. Meanwhile, the individual blanking control mechanisms for each beam in the blanking aperture array mechanism 204 switch each beam that is scheduled to be controlled to be beam-on from the beam-off state to the beam-on state after the shot cycle start timing. The individual blanking control mechanisms for each beam switch from the beam-on state to the beam-off state after the individually set irradiation time has elapsed. Thus, each beam switches from the beam-off state to the beam-on state in accordance with the operation of the individual blanking control mechanism, and after the individually set irradiation time has elapsed, switches from the beam-on state to the beam-off state. Then, the array light source 201 stops generating each excitation light beam 200 after a predetermined time equal to or greater than the maximum irradiation time Ttr has elapsed from the shot cycle start timing. With this operation, even if a leakage beam occurs in any of the beams in the multi-photoelectron beams 20, photoelectrons are not generated while the excitation light beam 200 is stopped, so that the leakage beam can be prevented. For example, if the ON / OFF ratio of the excitation light 200 is 1:1, the leakage beam can be reduced to 50% or less compared to when the excitation light 200 is always ON.

[0049] Fig. 10 is a time chart showing an example of the timing of switching the generation / stop of excitation light and the timing of switching ON / OFF of a certain beam in Modification 1 of Embodiment 1. Like Fig. 9, Fig. 10 shows an ON / OFF timing chart showing the generation / stop of excitation light, a timing chart of ON / OFF drive when performing individual blanking control of a certain beam of the blanking aperture array mechanism 204, and a timing chart of ON / OFF of the beam accompanying the individual blanking control. The example of Fig. 10 shows the k-th shot of the multi-photoelectron beam 20 and the k+1-th shot of the multi-photoelectron beam 20.

[0050] 10 , for each shot of the multi-photoelectron beam 20, the control circuit 160 generates a predetermined number of pulses of the excitation light 200 from a stopped state, and controls each beam to be controlled to be ON before the start of generation of the pulses of the excitation light 200, simultaneously with the generation of the pulses of the excitation light 200, or at the pulse-OFF timing between pulses after the start of generation of the pulses of the excitation light 200. The control circuit 160 then controls the blanking aperture array mechanism 204 to switch each beam controlled to be ON from the beam-ON state to the beam-OFF state after the generation of the number of pulses corresponding to the required dose. The pulses of each excitation light 200 are generated, for example, at a predetermined timing and a predetermined pitch. The pulse duration and pitch are set so that the irradiation time of each individual beam can be controlled. If the maximum irradiation time Ttr is defined, for example, as 1023 gradations, the generation time of one pulse is defined, for example, as the time for one gradation. In this case, the individual blanking control mechanisms for each beam in the blanking aperture array mechanism 204 switch each beam that is scheduled to be controlled to be beam-on from a beam-off state to a beam-on state at the shot cycle start timing. Meanwhile, the array light source 201 starts generating each excitation light 200 after the shot cycle start timing. The individual blanking control mechanisms for each beam switch from a beam-on state to a beam-off state after generating the number of pulses corresponding to the individually set irradiation time. The array light source 201 stops after generating the number of pulses corresponding to an irradiation time equal to or longer than the maximum irradiation time Ttr.

[0051] However, the present invention is not limited to this, and the pulse width and pitch of the pump light 200 may be set to be variable.

[0052] FIG. 11 is a time chart illustrating another example of the timing for switching the on / off of excitation light and the timing for switching the beam on / off of a certain beam in Modification 1 of Embodiment 1. In the example of FIG. 11, if the maximum irradiation time Ttr is defined by, for example, 8 gradations, one pulse is generated for one gradation, and pulses with 1x, 2x, and 4x durations are generated for 7 gradations. Note that the 0th gradation may be an appropriate timing when the excitation light is stopped, or may be controlled as a pulse with a 0x duration. In this case, the individual blanking control mechanism for each beam in the blanking aperture array mechanism 204 controls the beam to switch from the OFF state to the ON state at the pulse-OFF timing between pulses after the start of generation of the excitation light 200 pulses during the period when the excitation light 200 pulses are generated. The individual blanking control mechanism for each beam controls the beam to switch from the ON state to the OFF state at the timing when only the number of pulses corresponding to the required dose has been acquired. In the example of FIG. 11, pulses are combined in each shot, and ON / OFF switching timings are shown for beams with irradiation times for 3 and 7 gradations.

[0053] 12 is a time chart showing another example of the timing of switching between generation and stop of excitation light and the timing of switching ON / OFF of a certain beam in Modification 2 of Embodiment 1. The example of Fig. 12 shows a case where, among the control contents shown in Fig. 9, the timing of switching to beam OFF is synchronized with the timing of stopping the excitation light 200.

[0054] 12, the control circuit 160 switches the excitation light 200 from a stopped state to a generated state for each shot of the multi-photoelectron beam 20, generates the excitation light 200 for a predetermined period, and controls each beam that is to be controlled to be beam-on while the excitation light 200 is being generated to be switched from a beam-off state to a beam-on state. The control circuit 160 then controls each beam that is controlled to be beam-on to be switched from a generated state to a stopped state in synchronization with the timing at which each beam controlled to be beam-on is switched from the beam-on state to the beam-off state. Specifically, the individual blanking control mechanisms for each beam in the blanking aperture array mechanism 204 calculate backwards the start timing of the individually set irradiation time from the stop timing of the excitation light 200, and switch each beam that is to be controlled to be beam-on from a beam-off state to a beam-on state at the obtained start timing. Meanwhile, the array light source 201 starts generating the excitation light 200 simultaneously with the first start timing of each beam or at the shot cycle start timing set before that. Then, the array light source 201 stops generating the excitation light 200 after a predetermined time has elapsed from the shot cycle start timing. The individual blanking control mechanism for each beam switches from a beam-on state to a beam-off state in accordance with the timing at which the excitation light 200 is stopped. Therefore, each beam is turned off in accordance with the operation of the individual blanking control mechanism in accordance with the timing at which the excitation light 200 is stopped. When turning off a beam by blanking deflection, it may take time for the beam to fall. In the array light source 201, the laser oscillator provides a higher response time for switching the excitation light 200 on and off than an individual blanking control mechanism. Therefore, by synchronizing the timing at which the excitation light 200 is stopped and the timing at which the beam is turned off, it is possible to cut off leakage beams during the beam fall period.

[0055] 13 is a time chart showing another example of the timing of switching between generation and stop of excitation light and the timing of switching ON / OFF of a certain beam in Modification 3 of Embodiment 1. The example of Fig. 13 shows a case where, among the control contents shown in Fig. 9, the timing of switching to ON the beam (irradiation start timing) is synchronized with the timing of generation of the excitation light 200.

[0056] In FIG. 13 , the control circuit 160 controls each beam to be turned ON from the beam OFF state to the beam ON state in synchronization with the timing of switching the excitation light 200 from the stopped state to the generating state for each shot of the multi-photoelectron beam 20. The control circuit 160 also controls each beam that was turned ON from the beam ON state to the beam OFF state before switching the excitation light 200 from the generating state to the stopped state. Specifically, the individual blanking control mechanisms for each beam in the blanking aperture array mechanism 204 switch each beam that was turned ON from the beam OFF state to the beam ON state at the start of the shot cycle. When turning the beam ON by blanking deflection, it may take time for the beam to rise. The array light source 201 uses a laser oscillator to provide a faster ON / OFF switching response for the excitation light 200 than an individual blanking control mechanism. Therefore, the array light source 201 starts generating the excitation light 200 in synchronization with the time when the beam rise time has elapsed from the start of the shot cycle. Therefore, each beam is turned on at the timing when the generation of the excitation light 200 starts. Then, the individual blanking control mechanism for each beam switches from the beam on state to the beam off state after the individually set irradiation time has elapsed. The array light source 201 stops generating the excitation light 200 after a predetermined time equal to or greater than the maximum irradiation time Ttr has elapsed from the shot cycle start timing. By synchronizing the timing when the generation of the excitation light 200 starts and the timing when the beam is turned on, it is possible to cut off the leakage beam during the rise period of the beam. Furthermore, since the dose can be cut during the rise period, the accuracy of the dose amount can be improved.

[0057] As described above, in the first embodiment, for each shot of the multi-photoelectron beam 20, the timing of switching the generation / stop of the excitation light 200 and the timing of switching the beam ON / OFF of each beam are linked, and individual blanking control is performed by deflecting each beam of the multi-photoelectron beam 20 using the blanking aperture array mechanism 204, thereby individually switching the beam ON / OFF of each beam.

[0058] Then, the drawing mechanism 150 draws a pattern on the sample 101 using the multi-photoelectron beams controlled to be beam-on.

[0059] As described above, according to embodiment 1, in multi-beam writing, the difference in the amount of light received by each region (electron emission position) of the photocathode 218 that forms the electron beam can be reduced, i.e., uniformity can be improved.

[0060] Embodiment 2 In the first embodiment, the configuration has been described in which a plurality of excitation beams 50 from the array light source 201 are arranged in a square lattice pattern on the incident surface of the multi-lens array 212, but the present invention is not limited to this. The configuration of the imaging device 100 is the same as that shown in FIG.

[0061] FIG. 14 is a diagram showing an example of the irradiation positions of multiple excitation lights illuminating the multi-lens array in the second embodiment. The example in FIG. 14 shows, for example, 7×5 individual lenses 14 among the multiple individual lenses 14 constituting the multi-lens array 212. The multiple individual lenses 14 are arranged in an array. The example in FIG. 14 shows a case where multiple excitation lights 50 are arrayed in a staggered pattern. For example, this can be achieved by arranging the light sources of the array light source 201 in a staggered pattern. In other words, in adjacent rows in the y direction, the centers of the excitation lights 50 are arranged at a pitch P, with the centers shifted by a distance d in the x direction. It is preferable that the distance d be the arrangement pitch of the individual lenses 14, for example. In other words, rows in which the centers of the excitation lights 50 are arranged at a pitch P in the x direction and rows in which the centers of the excitation lights 50 are shifted by one individual lens 14 in the x direction and arranged at a pitch P, are alternately arranged in the y direction. In this way, it is also preferable to illuminate the multi-lens array 212 with multiple excitation lights 50 while shifting their positions.

[0062] 14, similarly to Fig. 2, each excitation light 50 from the array light source 201 illuminates a portion of the individual lenses 14 that make up the multi-lens array 212. Furthermore, at least a portion of the individual lenses 14 that make up the multi-lens array 212 is irradiated with two or more excitation lights 50.

[0063] In the example of FIG. 14 , the multiple excitation light beams 50 illuminate the multi-lens array 212 at a pitch P that is, for example, twice the arrangement pitch d between the individual lenses 14. Each excitation light beam 50 illuminates multiple individual lenses 14, for example, 3×3 individual lenses 14, with the central individual lens 14 as the center. In the example of FIG. 14 , the spot diameter of each excitation light beam 50 includes, for example, the entire central individual lens 14 (lens 1), the entire two individual lenses 14 (lens 2) on either side of the central individual lens 14 in the x direction, and the entire two individual lenses 14 (lens 3) on either side of the central individual lens 14 in the y direction, as well as portions of each of the four individual lenses 14 (lens 3) diagonally adjacent to the central individual lens 14. As shown in FIG. 3 , the individual lens 14 (lens 1) located at the center of the irradiation position of each excitation light beam 50 is irradiated with light of the maximum intensity, and therefore the amount of light received by the central individual lens 14 (lens 1) is large. In contrast, the intensity of the excitation light irradiated onto the peripheral individual lenses 14 is lower than that of the center. Therefore, the illuminance received by one excitation light on the peripheral individual lenses 14 is small.

[0064] In the second embodiment, the peripheral individual lenses 14 are illuminated with two or more excitation lights 50. In the example of FIG. 14 , the two individual lenses 14 (lens 2) on either side of the central individual lens 14 (lens 1) in the x direction are overlappingly illuminated with two excitation lights. The two individual lenses 14 (lens 3) on either side of the central individual lens 14 (lens 1) in the y direction and the four individual lenses 14 (lens 3) in the diagonal direction are overlappingly illuminated with three excitation lights. The two individual lenses 14 (lens 2) on either side of the central individual lens 14 in the x direction are entirely illuminated with low-illuminance excitation lights. Therefore, by being illuminated with two low-illuminance excitation lights, the illuminance can be made substantially the same as or approach the amount of light received by the central individual lens 14 (lens 1). The two individual lenses 14 (lenses 3) adjacent to each other in the y direction and the four individual lenses 14 (lenses 3) in the diagonal direction are only partially included in the spot diameter of each excitation light 50, so by being irradiated with three excitation lights, the illuminance can be made to be approximately the same as the amount of light received by the individual lens 14 (lens 1) located in the center, or can be made to approach the amount of light received by the individual lens 14 (lens 1) located in the center. In the example of Figure 14, the overlapping is different from the example of Figure 2, but even in the example of Figure 14, the difference in the amount of light received by each individual lens 14 can be reduced.

[0065] Other details are the same as those in the first embodiment.

[0066] Embodiment 3 In the above-described embodiments, the multi-lens array 212 is configured from a plurality of individual lenses 14 of the same size, but this is not limiting. In embodiment 3, the multi-lens array 212 is configured from a plurality of individual lenses 14 of different sizes. The configuration of the imaging device 100 is the same as that shown in FIG.

[0067] FIG. 15 is a diagram showing an example of the irradiation positions of multiple excitation light beams illuminating a multi-lens array in the third embodiment. The example of FIG. 15 shows, for example, 7×5 individual lenses 14 among the multiple individual lenses 14 constituting the multi-lens array 212. The multiple individual lenses 14 are arranged in an array. The multiple individual lenses 14 include individual lenses 14-1 and 14-2 of multiple sizes. The example of FIG. 15 shows, for example, a case where multiple individual lenses 14-1 and 14-2 of two sizes, large and small, are used. The example of FIG. 15 shows a case where multiple excitation light beams 50 are arrayed in a square lattice pattern on the upper surface of the multi-lens array 212. In this case, the small-sized individual lens 14-1 is used as the individual lens irradiated in the central portion of the excitation light beam 50. The large-sized individual lens 14-2 is used as the individual lens irradiated in the peripheral portion of the excitation light beam 50.

[0068] 15, similarly to Fig. 2, each of the plurality of excitation lights 50 from the array light source 201 illuminates a portion of the plurality of individual lenses 14-1, 14-2 among the plurality of individual lenses 14 constituting the multi-lens array 212. Furthermore, each of the large-sized individual lenses 14-2 among the plurality of individual lenses 14 constituting the multi-lens array 212 is irradiated with two or more excitation lights 50.

[0069] 15, the multiple excitation light beams 50 illuminate the multi-lens array 212 at a pitch P that is, for example, twice the arrangement pitch d between the individual lenses 14. Each excitation light beam 50 illuminates multiple individual lenses 14, for example, around the central individual lens 14 of the 3×3 individual lenses 14. The example of FIG. 15 shows a case where the spot diameter of each excitation light beam 50 includes, for example, the entire central individual lens 14-1 and parts of each of the eight individual lenses 14-2 surrounding the central individual lens 14-1.

[0070] 15, four individual lenses 14-2 (lens 2) adjacent to the central individual lens 14-1 (lens 1) in the x and y directions are irradiated with two excitation lights, and four individual lenses 14-3 (lens 3) in diagonal directions are irradiated with four excitation lights each.

[0071] As shown in FIG. 3 , the individual lens 14-1 located at the center of the irradiation position of each excitation light 50 is irradiated with light of the maximum intensity. Therefore, by reducing the lens size, the number of incident light beams can be limited. As a result, the amount of light received by the central individual lens 14-1 can be reduced. In contrast, the intensity of the excitation light irradiated to the peripheral individual lenses 14-2 is lower than that of the center. Therefore, the amount of light received by the peripheral individual lenses 14 from one excitation light beam is small. Therefore, by increasing the lens size, the number of incident light beams can be increased. Furthermore, light beams are incident from multiple excitation light beams 50. Compared to the four individual lenses 14-2 (lens 2) on either side in the x and y directions, the four individual lenses 14-2 (lens 3) in the diagonal direction have a smaller irradiation area per excitation light beam. Therefore, the illuminance can be adjusted by increasing the number of excitation light beams irradiated to the four individual lenses 14-2 (lens 3) in the diagonal direction compared to the four individual lenses 14-2 (lens 2) on either side in the x and y directions. As a result, the variation in illuminance of each individual lens 14 can be reduced.

[0072] FIG. 16 is a top view showing the distribution of illuminance when excitation light 50 irradiates multi-lens array 212, illustrating an example of the arrangement of small individual lenses in the third embodiment. Fig. 17 is a diagram showing an example of a histogram of light incident on a small-sized individual lens in embodiment 3. The example in Fig. 16 shows a case where a small-sized individual lens 14-1 is placed at the center of the spot of excitation light 50. In this case, as shown in Fig. 17, it can be seen that many light beams with a narrow range of intensities are incident. In this case, the integrated value of the histogram of the amount of light received by individual lens 14-1 (lens light collection intensity) was 27 (unit: AU).

[0073] FIG. 18 is a top view showing the distribution of illuminance when excitation light 50 irradiates multi-lens array 212, illustrating another example of the arrangement of small individual lenses in a comparative example of the third embodiment. Fig. 19 is a diagram showing another example of a histogram of light incident on a small-sized individual lens in a comparative example of embodiment 3. The example of Fig. 18 shows a case where a small-sized individual lens 14-1 is placed between two spots of excitation light 50. In this case, as shown in Fig. 19, the width of the intensity band of the incident light does not change significantly compared to the case of Fig. 17, but it can be seen that the low intensity band is shifted downward compared to the case of Fig. 17. The amount of light received by the individual lens 14-1 (lens light collection intensity) in this case was 10 (unit: AU).

[0074] FIG. 20 is a top view showing the distribution of illuminance when excitation light 50 irradiates multi-lens array 212, illustrating another example of the arrangement of large individual lenses according to the third embodiment. FIG. 21 shows another example of a histogram of light incident on a large-sized individual lens in the third embodiment. The example in FIG. 20 shows a case where a large-sized individual lens 14-2 is disposed between two spots of excitation light 50. In this case, as shown in FIG. 21, it can be seen that the low-intensity band is shifted downward compared to the case in FIG. 17, but the width of the intensity band of the incident light is wider compared to the case in FIG. 17. Therefore, it can be seen that a large amount of low-intensity light beams are incident. Furthermore, the amount of light received by the individual lens 14-2 in this case (lens condensed light intensity) was 28 (unit: AU). Therefore, it can be seen that an amount of light received equivalent to that obtained when a small-sized individual lens 14-1 is disposed at the center of the spot of excitation light 50, as shown in FIGS. 16 and 17, can be obtained.

[0075] As shown by the above results, by placing a small individual lens 14-1 in the center of the excitation light 50 spot and placing a large individual lens 14-2 between each excitation light 50 spot, the variation in illuminance of each individual lens 14 can be reduced.

[0076] In the above example, the multi-lens array 212 is configured by combining two types of lens sizes, but the present invention is not limited to this.

[0077] FIG. 22 is a diagram showing an example of the irradiation positions of multiple excitation light beams illuminating a multi-lens array in a modified example of the third embodiment. The example of FIG. 22 shows, for example, 7×5 individual lenses 14 among the multiple individual lenses 14 constituting the multi-lens array 212. The multiple individual lenses 14 are arranged in an array. The multiple individual lenses 14 include individual lenses 14-1, 14-2, and 14-3 of multiple sizes. The example of FIG. 22 shows a case where, for example, multiple individual lenses 14-1, 14-2, and 14-3 of three sizes (large, medium, and small) are used. The example of FIG. 22 shows a case where multiple excitation light beams 50 are arrayed in a square lattice pattern on the upper surface of the multi-lens array 212. In this case, the small-sized individual lens 14-1 is used as the individual lens irradiated in the central portion of the excitation light beam 50. The four individual lenses on both sides of the central individual lens 14-1 in the x and y directions are medium-sized individual lenses 14-2. The four individual lenses in the diagonal direction of the central individual lens 14-1 are large-sized individual lenses 14-3.

[0078] In the example of FIG. 22 , four medium-sized individual lenses 14-2 (lens 2) adjacent to the central individual lens 14-1 (lens 1) in the x and y directions are irradiated with two excitation light beams. Four large-sized individual lenses 14-3 (lens 3) in the diagonal direction are each irradiated with four excitation light beams. The illuminance of each excitation light beam incident on the four diagonal individual lenses 14-3 (lens 3) is low. Therefore, by using an individual lens 14-3 that is larger than the four diagonal individual lenses 14-2 (lens 2) adjacent to it in the x and y directions, the amount of received light can be increased. Conversely, the illuminance of each excitation light beam incident on the four diagonal individual lenses 14-2 (lens 2) is higher than the four diagonal individual lenses 14-3 (lens 3). Therefore, by using medium-sized individual lenses 14-2 that are smaller than the diagonal individual lenses 14-3 (lens 3), the amount of received light can be reduced. Depending on the relationship between the placement position of the individual lenses and the spot position of the excitation light, it is possible to adjust the amount of received light more precisely than when two types of lens sizes are used.

[0079] In the above example, a case where a plurality of excitation lights 50 are arrayed in a square lattice pattern is shown, but similar to the case shown in Figure 14, a case where a plurality of excitation lights 50 are arrayed in a houndstooth pattern is also suitable.

[0080] Other details are the same as those in the first embodiment.

[0081] Embodiment 4 In each of the above-described embodiments, the cases where all of the multiple excitation lights from array light source 201 are incident on the same illumination lens have been described, but this is not limited to this. In embodiment 4, a configuration using a multi-lens array as the illumination lens will be described. The contents below are the same as any one of embodiments 1 to 3, except for the points that will be particularly described.

[0082] Fig. 23 is a conceptual diagram showing the configuration of a drawing device in embodiment 4. Fig. 23 is the same as Fig. 1 except that illumination multi-lens array 230 is arranged instead of illumination lens 202. Therefore, illumination multi-lens array 230 (second multi-lens array) is arranged between array light source 201 and multi-lens array 212 (first multi-lens array).

[0083] In a configuration in which multiple excitation lights from array light source 201 are all incident on the same illumination lens 202, the angles of excitation light 50 incident on multi-lens array 212 differ between excitation light passing through the center of illumination lens 202 and excitation light passing through the periphery, which can result in uneven illuminance on multi-lens array 212. In order to illuminate multi-lens array 212 with multiple excitation lights that are as uniform as possible, it is desirable for each excitation light to pass through the lens at as similar an angle as possible. To achieve this, it is desirable for each excitation light to pass through an individual lens.

[0084] Therefore, in the fourth embodiment, an illumination multi-lens array 230 is used in which an individual lens is arranged for each excitation light. The number of illumination individual lenses 13 that make up the illumination multi-lens array 230 may be the same as the number of light sources 11 that make up the array light source 201, or may be more or less. When the number of light sources 11 and illumination individual lenses 13 is the same, the individual lenses are arranged so that the line connecting the center of a pair of light sources 11 and the center of an illumination individual lens 13 coincides with the center of the trajectory of the excitation light output from that light source. The individual lenses that make up the illumination multi-lens array 230 are arranged so that they do not overlap with each other.

[0085] This configuration can eliminate or reduce unevenness in the plurality of excitation light beams 50 irradiated onto the multi-lens array 212. Therefore, the state of the plurality of excitation light beams 50 can be made closer to uniform.

[0086] FIG. 24 is a diagram showing an example of spot diameters of multiple excitation beams in the fourth embodiment. Multiple excitation beams 200 generated from the array light source 201 spread and illuminate the illumination multi-lens array 230 with a predetermined spot diameter. The example of FIG. 24 shows multiple excitation beams 50 with spot diameters on the illumination multi-lens array 230. Multiple excitation beams 52 are refracted by each individual illumination lens 13 of the illumination multi-lens array 230 and illuminate the multi-lens array 212. The example of FIG. 24 shows multiple excitation beams 50 with spot diameters on the multi-lens array 212. The example of FIG. 24 shows a case where the multiple excitation beams 52 are refracted by each individual lens of the illumination multi-lens array 230 and further spread to illuminate the multi-lens array 212. The illumination state of the multiple excitation beams 50 on the multi-lens array 212 is, for example, as shown in the example of FIG. 2, where they illuminate each individual lens 14 on the multi-lens array 212. Therefore, the pitch of the arranged individual lenses is different between multi-lens array 212 (first multi-lens array) and illumination multi-lens array 230 (second multi-lens array). While the arrangement pitch of the multiple individual lenses 14 in multi-lens array 212 is d, in illumination multi-lens array 230, the multiple illumination individual lenses 13 are arranged at an arrangement pitch p that is larger than the arrangement pitch d.

[0087] In the above example, the plurality of excitation light beams 50 are arrayed in a square lattice pattern, but it is also suitable if the plurality of excitation light beams 50 are arrayed in a staggered pattern, as in the case shown in Fig. 14. In such a case, the plurality of light sources 11 constituting the array light source 201 are also arranged in a staggered pattern, and the plurality of individual lenses constituting the illumination multi-lens array 230 are also arranged in a staggered pattern.

[0088] Furthermore, in the above example, the multi-lens array 212 is illuminated by one illumination multi-lens array 230 as the second multi-lens array, but it is also possible to add an additional illumination multi-lens array, thereby providing a plurality of illumination multi-lens arrays.

[0089] Other details are the same as those in the first embodiment.

[0090] Although the embodiments have been described above with reference to specific examples, the present invention is not limited to these specific examples.

[0091] In the above example, a 10-bit control signal is input to control each logic circuit 41, but the number of bits may be set as appropriate. For example, a 2-bit, or 3-9-bit control signal may be used. Note that a control signal of 11 or more bits may also be used.

[0092] Although the description of the device configuration, control method, and other parts not directly necessary for the explanation of the present invention have been omitted, the required device configuration and control method can be appropriately selected and used. For example, the description of the control unit configuration that controls the drawing device 100 has been omitted, but it goes without saying that the required control unit configuration can be appropriately selected and used.

[0093] In addition, all other multi-charged particle beam writing apparatuses and multi-charged particle beam writing methods that include the elements of the present invention and that can be appropriately modified by those skilled in the art are included within the scope of the present invention. [Explanation of symbols]

[0094] 11 Light source 12 Intensity distribution 13 Individual lighting lenses 14 individual lenses 20 Multi-photoelectron beam 22 holes 24 control electrode 25 Passing hole 26 Counter electrode 27 Control Grid 28 pixels 29 Sub-irradiation area 30 drawing area 32 stripe area 31 PCB 33 Support stand 34 Irradiation area 36 pixels 41 Control circuit 50,52 Excitation light 100 Drawing device 101 Sample 112 Array driving circuit 113 BAA drive circuit 150 Drawing mechanism 160 Control circuit 161 Overall control circuit 200 Excitation Light 201 Array Light Source 202 Lighting lens 220 Multi-anode electrode 203 Shaped Aperture Array Substrate 204 Blanking Aperture Array Mechanism 205 Electron Lens 206 Limiting Aperture Substrate 207 Electron Lens 208 Objective deflector 210 Photoelectron emission mechanism 212 Multi-lens array 214 Glass substrate 216 Multi-light-shielding film 218 Photocathode 230 Illumination Multi-Lens Array 330 Membrane Region 332 Outer area

Claims

1. an array light source having a plurality of light sources and generating a plurality of first lights; a multi-lens array having a plurality of lenses, wherein each of the plurality of first light beams illuminates a part of the plurality of lenses, and at least a part of the plurality of lenses is irradiated with two or more of the first light beams, thereby dividing the plurality of first light beams into a plurality of second light beams; a photocathode that receives the plurality of second light beams from a front surface and emits multiple photoelectron beams from a rear surface; a blanking aperture array mechanism for performing individual blanking control for individually switching on / off each beam of the multi-photoelectron beam; an electron optical system that irradiates a sample with multiple photoelectron beams; A multi-electron beam lithography device comprising:

2. 2. The multi-electron beam writing apparatus according to claim 1, wherein the plurality of lenses include lenses of a plurality of sizes.

3. The multi-lens array is a first multi-lens array, 3. A multi-electron beam drawing apparatus according to claim 1, further comprising at least a second multi-lens array between said array light source and said first multi-lens array.

4. 4. The multi-electron beam drawing apparatus according to claim 3, wherein the first multi-lens array and the second multi-lens array have lenses arranged at different pitches.

5. The multi-electron beam lithography device according to any one of claims 1 to 4, further comprising a control circuit that links the timing of switching on / off the first light with the timing of switching on / off the beams of each beam for each shot of the multi-electron beam.

6. generating a plurality of first lights from an array light source having a plurality of light sources; a step of splitting the plurality of first light beams into a plurality of second light beams by using a multi-lens array having a plurality of lenses, with each of the plurality of first light beams illuminating a part of the plurality of lenses, and at least a part of the plurality of lenses being irradiated with two or more of the first light beams among the plurality of first light beams; a step of making the plurality of second light beams incident on a front surface of a photocathode and emitting the multi-photoelectron beams from a rear surface of the photocathode; performing individual blanking control for individually switching on / off each beam of the multiple photoelectron beams using a blanking aperture array mechanism; writing a pattern on a sample using multiple photoelectron beams; A multi-electron beam writing method comprising:

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