Multi-charged particle beam writing method and multi-charged particle beam writing apparatus

Abstract

To simultaneously solve the space retention of secondary electrons and the beam location fluctuation due to deflector electrode charging.SOLUTION: A multi-charged particle beam drawing method includes the steps for forming a multi-charged particle beam to be irradiated on a substrate to be drawn, deflecting the multi-charged particle beam to a position added with a predetermined deflection offset so that a state in which a total deflection voltage is zero is not included in a range of each deflection voltage applied to each of a plurality of electrodes of an electrostatic positioning deflector, and irradiating the substrate with the multi-charged particle beam. A positive common voltage is added to each of the deflection voltages and the resulting voltage is applied to each electrode of the positioning deflector.SELECTED DRAWING: Figure 13

Description

[Technical Field]

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

[0002] As LSIs become more highly integrated, the circuit line width required for semiconductor devices is becoming finer every year. To form the desired circuit pattern on a semiconductor device, a method is adopted in which a high-precision original pattern (called a mask, or a reticle, especially when used in steppers and scanners) formed on quartz is reduced and transferred onto a wafer using a reduction projection exposure system. The high-precision original pattern is drawn using an electron beam drawing system, using so-called electron beam lithography technology.

[0003] One type of electron beam lithography system is a multi-beam electron beam lithography system that uses multiple beams. Compared to lithography systems that use a single electron beam, a multi-beam electron beam lithography system can irradiate many beams at once, thereby significantly improving throughput.

[0004] In a multi-electron beam lithography system, the beam for each shot is focused on the surface of the substrate to be lithographed using an objective lens, and an electrostatic lens is used to dynamically correct the focus (dynamic focus) during lithography to accommodate the unevenness of the substrate surface. When this electrostatic lens is operated in the negative voltage range, secondary electrons generated by electron beam lithography return to the substrate surface, causing the resist to become charged, and the lithography pattern becomes unstable. position This hinders improvement of accuracy.

[0005] In order to suppress the influence of returning secondary electrons, etc., it is preferable to operate the electrostatic lens in a positive voltage range relative to the substrate surface and guide the secondary electrons upward from the substrate surface. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-071354 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-268755 [Patent Document 3] International Publication No. 2011 / 108368 [Patent Document 4] Japanese Unexamined Patent Publication No. 61-101944 [Patent Document 5] Japanese Patent Application Laid-Open No. 2013-197289 [Patent Document 6] Japanese Patent Application Publication No. 2018-170435 [Patent Document 7] Japanese Patent Application Publication No. 2019-212766 [Non-patent literature]

[0007] [Non-Patent Document 1] Hirofumi Morita, Junichi Kato and Nobuo Shimazu, Basic characteristics of beam position drift and field stitching error caused by electron beam column charging, Japanese Journal of Applied Physics Vol.35(1996), Part 1, No.7, July 1996, pp.4121-4127. Summary of the Invention [Problem to be solved by the invention]

[0008] However, when the electrostatic lens is operated in the positive voltage range, secondary electrons from the substrate surface suddenly decelerate after passing through the electrostatic lens and remain densely on the beam trajectory, or they become charged by non-conductive dirt (contamination) on the inner surface of the deflector electrodes, which changes the electric field near the electron beam, altering the electron beam trajectory and degrading the beam position accuracy.

[0009] Non-Patent Document 1, which reports research on drift due to the influence of charging of deflector electrodes, describes a phenomenon in which drift can be reduced by deflecting (deflection offset) in a narrow region centered on the deflection destination. However, in the variable shaped beam lithography device that was the subject of experiments in Non-Patent Document 1 and has been widely used in industry, the dimensions of the deflection region used for lithography significantly affect lithography throughput, and lithography using only the narrow region of the deflection destination results in a significant decrease in throughput. For these reasons, the phenomenon described in Non-Patent Document 1, in which drift is reduced by deflecting in a narrow region centered on the deflection destination, is extremely difficult to put into practical use and has never actually been used in industry.

[0010] In a multi-beam writing apparatus, unlike a variable shaped beam apparatus, there is almost no concern about a decrease in throughput even if the deflection area dimensions are small, so there is a possibility that the above phenomenon can be utilized.

[0011] However, deflection (deflection offset) to reduce drift creates a new problem: increased array distortion (displacement between individual beams from their ideal positions). Reducing array distortion is a new requirement for multi-beam optical systems. Multi-beam optical systems form very large array beams, for example, approximately 100 μm in length and width. Therefore, unlike variable shaped beam optical systems that form small beams of approximately 1 μm or less, array distortion is likely to increase. Therefore, reducing array distortion in the design is extremely difficult and important. Here, using deflection offset to reduce drift increases the array distortion caused by the deflection, degrading drawing accuracy.

[0012] A configuration in which the deflector is located within the lens magnetic field (so-called in-lens configuration) is known to be effective in reducing array distortion caused by deflection. To reduce array distortion caused by deflection, multiple deflectors are often arranged in stages and the deflection amount and direction of each deflector are optimized. However, for the high level of distortion reduction required for multi-beam lithography systems, it is practically necessary to locate one deflector within the lens magnetic field (in-lens configuration) as a prerequisite for optimization. On the other hand, the electrostatic correction lens must be located within the lens magnetic field (similarly in-lens configuration) to achieve sufficient correction sensitivity (focus correction sensitivity and rotation correction sensitivity) for practical use (see JP 61-101944 A and JP 2013-197289 A). As a result, it is necessary to locate the correction lens near the center of the magnetic pole and the deflector directly above the correction lens in close proximity to the lens magnetic field.

[0013] However, placing the deflector close to the electrostatic correction lens creates a new problem: secondary electrons from the sample surface decelerate and become trapped when they pass through the correction lens and enter the deflector, causing beam (primary beam) instability (drift). As a countermeasure against drift caused by the deceleration of secondary electrons, Japanese Patent Application Laid-Open Publication No. 2018-170435 discloses a technique for placing an electrode to which a positive voltage is applied directly above the electrostatic correction lens. Japanese Patent Application Laid-Open Publication No. 2019-212766 also discloses a technique for extending the positively charged electrode of the electrostatic correction lens upstream to a location where the lens magnetic field attenuates. However, using these techniques, the presence of additional electrodes or extended correction lens electrodes forces the deflector to be located upstream from the lens magnetic pole, where the magnetic field attenuates (i.e., in-lens placement is not possible), which creates a problem of making it difficult to reduce array distortion caused by deflection.

[0014] As described above, in the conventional multi-beam optical system, it has not been possible to simultaneously reduce the beam position fluctuation due to deflector charging by secondary electrons, reduce the beam position fluctuation due to secondary electron retention, and reduce the multi-beam array distortion.

[0015] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a multi-charged particle beam writing method and a multi-charged particle beam writing apparatus that can simultaneously solve the problems of spatial retention of secondary electrons and fluctuations in beam position due to deflector electrode charging, while suppressing an increase in array distortion. [Means for solving the problem]

[0016] A multi-charged particle beam writing method according to one aspect of the present invention comprises the steps of: forming a multi-charged particle beam to be irradiated onto a substrate to be written; deflecting the multi-charged particle beam to a position to which a predetermined deflection offset has been added so that the range of each deflection voltage applied to each of a plurality of electrodes of an electrostatic positioning deflector does not include a state in which the total deflection voltage is zero; and irradiating the multi-charged particle beam onto the substrate, wherein a positive common voltage is added to each deflection voltage and applied to each electrode of the positioning deflector.

[0017] A multi-charged particle beam drawing apparatus according to one aspect of the present invention comprises an electrostatic positioning deflector having a plurality of electrodes for deflecting a multi-charged particle beam to be irradiated onto a substrate to be drawn, and a deflection control circuit for controlling the deflection of the multi-charged particle beam to a position to which a predetermined deflection offset has been added so that the range of each deflection voltage applied to each of the plurality of electrodes does not include a state in which the total deflection voltage is zero, and a positive common voltage is added to each of the deflection voltages and applied to each electrode of the positioning deflector. [Effects of the Invention]

[0018] According to the present invention, it is possible to simultaneously solve the problems of spatial retention of secondary electrons and fluctuations in beam position due to charging of deflector electrodes while suppressing an increase in array distortion. [Brief explanation of the drawings]

[0019] [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 schematic diagram of a shaping aperture array substrate. [Figure 3] FIG. 3 is a cross-sectional view of a second objective lens. [Figure 4] 10(a) and 10(b) are diagrams illustrating the trajectories of secondary electrons according to a comparative example. [Figure 5] 10A and 10B are diagrams illustrating a deflectable range and a drawing deflection region. [Figure 6] 10(a) to 10(d) are diagrams illustrating the position of a writing deflection region where the polarity of the deflection voltage is constant. [Figure 7] FIG. 2 is a diagram illustrating an example of the configuration of a positioning deflector. [Figure 8] 1A and 1B are diagrams illustrating an example of the configuration of a positioning deflector. [Figure 9] 10(a) to 10(c) are diagrams illustrating the position of a writing deflection region where the polarity of the deflection voltage is constant. [Figure 10] 10(a) and 10(b) are diagrams illustrating the position of a drawing deflection region where the polarity of the deflection voltage is constant. [Figure 11] FIG. 10 is a cross-sectional view of a second objective lens when a magnetic deflector is provided near an electrostatic positioning deflector. [Figure 12] 1(a) and 1(b) are diagrams illustrating the trajectories of secondary electrons. [Figure 13] 3A and 3B are diagrams illustrating the configuration of a positioning deflector and voltages applied to each electrode. [Figure 14] 3A and 3B are diagrams illustrating the configuration of a positioning deflector and voltages applied to each electrode. DETAILED DESCRIPTION OF THE INVENTION

[0020] 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.

[0021] 1 includes a drawing unit 10 that draws a desired pattern on an object such as a mask or a wafer by irradiating it with an electron beam, and a control unit 60 that controls the operation of the drawing unit 10. The drawing unit 10 is an example of a multi-beam drawing device that includes an electron optical lens barrel 12 and a drawing chamber 40.

[0022] Arranged within the electron optical column 12 are an electron gun 14, an illumination lens 16, a shaping aperture array substrate 18, a blanking aperture array substrate 20, a projection lens 22, a stopping aperture (limiting aperture member) 24, a first objective lens 26, a positioning deflector 28, a second objective lens 30, and a focus correction lens 32. An XY stage 42 is arranged within the writing chamber 40. A mask blank, which is a substrate 44 to be written, is placed on the XY stage 42.

[0023] Substrate 44 includes, for example, a wafer, or an exposure mask for transferring a pattern onto a wafer using a stepper, scanner, or other reduction projection exposure device that uses an excimer laser as a light source, or an extreme ultraviolet exposure device. Substrate 44 also includes a mask on which a pattern is already formed. For example, a Levenson mask requires two drawing operations, so a second pattern may be drawn on an object that has been drawn once and processed into a mask.

[0024] As shown in Fig. 2, apertures (first apertures) 18A are formed in m columns by n rows (m, n ≥ 2) at a predetermined arrangement pitch on the shaping aperture array substrate 18. Each aperture 18A is formed as a rectangle of the same dimensions. The shape of the apertures 18A may be circular. Multiple beams MB are formed by portions of the electron beams B passing through each of the plurality of apertures 18A.

[0025] The blanking aperture array substrate 20 is provided below the shaping aperture array substrate 18, and has formed therein passage holes 20A (second openings) corresponding to the respective openings 18A of the shaping aperture array substrate 18. A blanker (not shown), consisting of a pair of two electrodes, is disposed in each passage hole 20A. One of the blankers is fixed at ground potential, and the other is switched to a potential different from ground potential. The electron beams passing through each passage hole 20A are deflected independently by the voltage applied to the blanker. In this manner, the multiple blankers perform blanking deflection on the corresponding beams among the multi-beams MB that have passed through the multiple openings 18A of the shaping aperture array substrate 18.

[0026] The stopping aperture 24 blocks the beam deflected by the blanker. The beam not deflected by the blanker passes through an opening 24A (third opening) formed in the center of the stopping aperture 24. The stopping aperture 24 is placed on the image plane of the crossover (light source image) where the beam divergence becomes smaller, in order to reduce beam leakage during individual blanking by the blanking aperture array substrate 20.

[0027] The control unit 60 has a control computer 62, a deflection control circuit 64, and a lens control circuit 66. The deflection control circuit 64 controls the voltages applied to the blanker provided on the blanking aperture array substrate 20 and the electrodes of the positioning deflector 28. The lens control circuit 66 controls the voltages applied to the illumination lens 16, the projection lens 22, the first objective lens 26, the second objective lens 30, and the focus correction lens 32. For example, the lens control circuit 66 controls the voltage applied to the focus correction lens 32 based on the surface height of the substrate 44 detected by a Z sensor (not shown), thereby performing focus correction (dynamic focus).

[0028] Electron beam B emitted from electron gun 14 (emission section) is illuminated almost perpendicularly by illumination lens 16 onto the entire shaping aperture array substrate 18. Electron beam B passes through multiple apertures 18A in shaping aperture array substrate 18, forming a multibeam MB consisting of multiple electron beams. The multibeam MB passes through the corresponding blankers in blanking aperture array 20.

[0029] The multi-beams MB that have passed through the blanking aperture array substrate 20 are reduced in size by the projection lens 22 and proceed toward the central opening 24A of the stopping aperture 24. Here, the electron beams deflected by the blanker of the blanking aperture array substrate 20 move out of position with respect to the opening 24A of the stopping aperture 24 and are blocked by the stopping aperture 24. On the other hand, the electron beams that have not been deflected by the blanker pass through the opening 24A of the stopping aperture 24. Blanking control is performed by turning the blanker on and off, and the on / off of the beam is controlled.

[0030] In this way, the stopping aperture 24 blocks each beam deflected by the blanker of the blanking aperture array substrate 20 to be in the beam OFF state.

[0031] The multi-beams MB that have passed through the stopping aperture 24 are focused by the first objective lens 26, the second objective lens 30, and the focus correction lens 32 to form a pattern image with a desired reduction ratio, which is then irradiated onto the substrate 44.

[0032] A positioning deflector 28, disposed between the first objective lens 26 and the second objective lens 30, deflects and irradiates the multibeam MB onto a desired position on a substrate 44 placed on a continuously moving XY stage 42. The positioning deflector 28 has a plurality of electrodes, and may be, for example, a quadrupole deflector with four electrodes or an octupole deflector with eight electrodes. The beam deflection position (the beam irradiation position on the substrate 44) can be changed by changing the voltage applied to each electrode of the positioning deflector 28.

[0033] Because the area of ​​the substrate 44 irradiated with the multi-beam MB is as wide as about 100 micrometers square, there is no problem with the writing throughput even if the area to be deflected by the positioning deflector 28 (writing deflection area) is narrower than the size of the multi-beam MB. For example, a size of a few micrometers square to about 10 micrometers square is sufficient. This is a major difference from a variable-shape electron beam writing apparatus, which requires a wide writing deflection area of ​​about 100 micrometers square to achieve writing throughput.

[0034] The focus correction lens 32 is disposed downstream of the positioning deflector 28 in the traveling direction of the multi-beams MB.

[0035] Electromagnetic lenses (magnetic lenses) are used for the illumination lens 16, projection lens 22, first objective lens 26, and second objective lens 30, but some or all of them may be electrostatic lenses. The focus correction lens 32 performs dynamic focus adjustment in response to height variations of the surface of the substrate 44, and is an electrostatic lens, but an electromagnetic lens (including a coil that generates an axially symmetric magnetic field) may also be used. It may also be configured as a multi-stage lens system in which the applied voltages and excitation currents change in conjunction with each other in a fixed relationship. Alternatively, the second objective lens 30 may also have the function of the focus correction lens 32, or the second objective lens 30 and the focus correction lens 32 may be configured to perform focus adjustment by interlocking with each other in a fixed relationship.

[0036] The second objective lens 30 is an electromagnetic lens, and has a coil 30a and a yoke 30b that houses the coil 30a, as shown in Fig. 3. The yoke 30b is made of a material with high magnetic permeability, such as iron, and has a notch (pole piece 30c) formed in one part.

[0037] Magnetic lines of force created by passing a current through the coil 30a leak into space via the pole piece 30c, creating a magnetic field.

[0038] The focus correction lens 32 is disposed, for example, inside the second objective lens 30, at the same height as the pole piece 30c. The focus correction lens 32 is an electrostatic lens having a ring-shaped electrode. A positive voltage with respect to the substrate surface is applied to this electrode, and the focus correction lens 32 is operated in a positive voltage range with respect to the substrate surface.

[0039] When the multi-beams MB (primary beams) are irradiated onto the substrate 44, secondary electrons are emitted from the substrate surface. By operating the focus correction lens 32 in the positive voltage range, the secondary electrons are guided upward from the substrate surface and travel upward inside the electron optical lens barrel 12. This prevents the secondary electrons from returning to the substrate surface, thereby suppressing positional fluctuations due to resist charging.

[0040] During the writing process, the resist on the surface of the substrate 44 may evaporate due to beam irradiation, and contamination (dirt) may adhere to the surfaces of the multiple electrodes of the positioning deflector 28. Secondary electrons traveling upward inside the electron optical column 12 may reach and charge the contamination on the electrode surfaces of the positioning deflector 28, which may change the trajectory of the multi-beam MB.

[0041] In conventional lithography devices, the operation of changing the beam deflection position (beam irradiation position on substrate 44) involves changing the polarity of the deflection voltage applied to each electrode of the positioning deflector 28, as shown in Figures 4(a) and 4(b). When the polarity of the deflection voltage changes, the strength and direction of the electric field within the positioning deflector 28 change significantly, and the arrival position of the secondary electrons, i.e., the charged position, changes significantly across the electrodes. This significant change in the charged position causes a large change in the electric field near the beam, resulting in a large fluctuation (drift) in the beam irradiation position.

[0042] Therefore, in this embodiment, an offset (deflection offset) is applied to the deflection position of the positioning deflector 28, i.e., the deflection position is shifted. This removes the secondary electrons from the beam center and moves them in a substantially constant horizontal direction until they reach a limited area, such as the deflector surface. For example, as shown in FIG. 5, the imaging deflection region R1 is shifted within the deflection range R0 so that the imaging deflection region R1 does not include the origin of the deflection voltage, i.e., the state where the deflection voltage of all electrodes of the positioning deflector 28 is 0 (total deflection voltage is 0). Here, the deflection range R0 is the range where deflection is possible with the maximum output of the deflection amplifier included in the deflection control circuit 64. The imaging deflection region R1 is the deflection region required for imaging processing. By not including the origin of the deflection voltage within the imaging deflection region R1, the arrival position of the secondary electrons, i.e., the change in the charging position relative to the change in the deflection position, is suppressed, as shown in FIGS. 12(a) and 12(b). This suppresses fluctuations (drifts) in the beam irradiation position.

[0043] Furthermore, it is more effective to set the deflection offset so that the polarity of the deflection voltage of each electrode (individual electrode) of the positioning deflector 28 remains constant. To keep the polarity of the deflection voltage of each electrode constant, the quadrupole deflector can be configured so that the drawing deflection region R1 falls within one of the regions R11 to R14 shown in Figures 6(a) to 6(d). This further limits the area where secondary electrons strike the deflection electrodes, thereby further limiting the range of positions where charging occurs. As a result, changes in the strength and direction of the electric field within the positioning deflector 28 are suppressed, beam irradiation position fluctuation (drift) is suppressed, and beam position accuracy is improved.

[0044] Furthermore, if "deflection offsets are set so that the polarity of the deflection voltage of each electrode is constant," then "a state in which the total deflection voltage is 0 is not included" is automatically (always) satisfied. Therefore, "constant polarity" is a more restrictive condition than "total deflection voltage does not include 0."

[0045] It should be noted that the conditions related to the voltage applied to the deflector contribute more directly to reducing drift. The result is that the beam deflection position and deflection area on the substrate surface shift, and it cannot be said that the beam deflection position and deflection area on the substrate surface themselves directly contribute to reducing drift.

[0046] Here, by applying a constant deflection offset during writing and setting the operational parameters so that the origin of the deflection during writing is shifted by the deflection offset, the beam can be irradiated at the desired position on the substrate 44. Although the deflection offset narrows the available writing deflection area, this is not a practical problem because a multi-beam writing device does not require a wide writing deflection area. Furthermore, keeping the deflection offset constant during writing is the most effective way to reduce drift. Note that, as mentioned above, the deflection offset may be slightly changed during writing, as long as it is within the range that satisfies the conditions of "deflection voltage not including 0" and "constant polarity." In this case, the position of the XY stage 42 must be corrected according to the amount of change in the deflection offset.

[0047] Fig. 7 shows an example of the configuration of the positioning deflector 28. In the example shown in Fig. 7, the positioning deflector 28 is an electrostatic quadrupole deflector having four electrodes 28a to 28d. When the deflection offset is (X0, Y0), the deflection amount for pattern drawing based on the pattern position of the drawing data is (X, Y), and the deflection sensitivity coefficient is k, the deflection voltages V1 to V4 applied to the electrodes 28a to 28d are as follows: V1=k(X0+X) V2=k(Y0+Y) V3=k(-X0-X) V4=k(-Y0-Y)

[0048] The deflection range in the x direction is -X M From X M The deflection range in the y direction is -Y M From Y M -X W From X WDeflect the deflection area in the y direction up to -Y W From Y W 5, the deflection offset (X0, Y0) is required to satisfy the following conditional expression so that the origin of the deflection voltage is not included in the writing deflection region R1 and so that the polarity of the deflection voltage of each electrode of the positioning deflector 28 is constant. X W <|X0|≦X M -X W Y W <|Y0|≦Y M -Y W

[0049] The deflection offset (X0, Y0) that satisfies the above conditional expression is determined in advance and stored in the memory (not shown) of the control unit 60.

[0050] During the writing process, the control computer 62 reads the writing data from the storage device and performs multiple stages of data conversion to generate shot data specific to the device. The shot data defines the dose and irradiation position coordinates of each shot. The irradiation position coordinates are calculated using the deflection offset (X0, Y0) described above as the origin of the deflection.

[0051] The control computer 62 outputs the dose for each shot based on the shot data to a deflection control circuit 64. The deflection control circuit 64 calculates the exposure time t by dividing the input dose by the current density. Then, when performing the corresponding shot, the deflection control circuit 64 applies a deflection voltage to the corresponding blanker on the blanking aperture array substrate 20 so that the blanker turns on the beam for the exposure time t.

[0052] The deflection control circuit 64 also determines the amount of deflection for drawing (X, Y) so that the beam is irradiated onto the irradiation position indicated by the shot data, adds or subtracts a deflection offset (X0, Y0) to this, and applies the above-mentioned deflection voltages V1 to V4 multiplied by a deflection sensitivity coefficient k to the electrodes 28a to 28d of the positioning deflector 28. When determining the amount of deflection for drawing, position information of the XY stage 42 is acquired from a position measuring device (not shown) such as a laser length measuring device and used.

[0053] In this way, the polarity of the deflection voltage of each deflection electrode of the positioning deflector 28 is kept constant, and the secondary electrons are guided to a limited area of ​​the positioning deflector 28, thereby suppressing changes in deflector charging and stabilizing the beam.

[0054] 8(a)(b), an octupole deflector having eight electrodes 28a to 28h may be used as the positioning deflector 28. The deflectors shown in Figures 8(a)(b) have an installation angle that differs by 22.5 degrees, and in this specification, the deflector in which the deflection coordinate axis passes through the center of the gap between the deflection electrodes as in (a) is referred to as a 22.5-degree rotated arrangement, and the deflector in which the deflection coordinate axis passes through the center of the deflection electrodes as in (b) is referred to as a 0-degree rotated arrangement.

[0055] In the 22.5-degree rotated arrangement shown in FIG. 8(a), the deflection voltages V1 to V8 applied to the electrodes 28a to 28h are expressed as follows using the deflection offset (X0, Y0), the drawing deflection amount (X, Y), and the deflection sensitivity coefficient k: V1=k{(X0+X)+a(Y0+Y)} V2=k{(Y0+Y)+a(X0+X)} V3=k{(Y0+Y)-a(X0+X)} V4=k{-(X0+X)+a(Y0+Y)} V5=k{-(X0+X)-a(Y0+Y)} V6=k{-(Y0+Y)-a(X0+X)} V7=k{-(Y0+Y)+a(X0+X)} V8=k{(X0+X)-a(Y0+Y)} a=√2-1≒0.414

[0056] In a 22.5 degree rotation arrangement, in order to ensure that the polarity of the deflection voltage of each electrode of the positioning deflector 28 is constant, the drawing deflection area should fall within either of the areas Ra (Ra1 to Ra4) of 22.5 degrees to 67.5 degrees shown in Figure 9(a) and every 90 degrees therefrom, or the area Rb (Rb1, Rb2) of -22.5 degrees to 22.5 degrees shown in Figure 9(b) and rotated 180 degrees therefrom, or the area Rc (Rc1, Rc2) of 67.5 degrees to 112.5 degrees shown in Figure 9(c) and rotated 180 degrees therefrom.

[0057] In order to fit the drawing deflection area into the area Ra, the deflection offset (X0, Y0) should satisfy the following conditional expression. |Y0|+Y W <(√2+1)(|X0|-X W ) |Y0|-Y W >(√2-1)(|X0|+X W ) |X0|≦X M -X W |Y0|≦Y M -Y W

[0058] In order to fit the drawing deflection area into the area Rb, the deflection offset (X0, Y0) should satisfy the following conditional expression. |Y0|+Y W <(√2-1)(|X0|-X W ) |Y0|-Y W >-(√2-1)(|X0|-X W ) |X0|≦X M -X W |Y0|≦Y M -Y W

[0059] In order to fit the drawing deflection area into the area Rc, the deflection offset (X0, Y0) should satisfy the following conditional expression. |X0|+X W <(√2-1)(|Y0|-Y W ) |X0|-XW >-(√2-1)(|Y0|-Y W ) |X0|≦X M -X W |Y0|≦Y M -Y W

[0060] In the 0-degree rotated arrangement shown in FIG. 8(b), the deflection voltages V1 to V8 applied to the electrodes 28a to 28h are expressed as follows using the deflection offset (X0, Y0), the drawing deflection amount (X, Y), and the deflection sensitivity coefficient k': V1=k´(X0+X) V2=k´b{(X0+X)+(Y0+Y)} V3=k´(Y0+Y) V4=k´b{-(X0+X)+(Y0+Y)} V5=-k´(X0+X) V6=-k´b{(X0+X)+(Y0+Y)} V7=-k´(Y0+Y) V8=-k´b{-(X0+X)+(Y0+Y)} b=1 / √2≒0.707

[0061] In the 0-degree rotation arrangement, in order to ensure that the polarity of the deflection voltage of each electrode of the positioning deflector 28 is constant, the drawing deflection area should fall within either the area Rd (Rd1 to Rd4) shown in Figure 10(a) which is symmetrical with respect to 0 degrees to 45 degrees, the x-axis, the y-axis, and the origin, or the area Re (Re1 to Re4) shown in Figure 10(b) which is symmetrical with respect to 45 degrees to 90 degrees, the x-axis, the y-axis, and the origin.

[0062] In order to fit the drawing deflection area into the area Rd, the deflection offset (X0, Y0) should satisfy the following conditional expression. |Y0|+Y W <|X0|-X W |X0|≦X M -X W |Y0|≦Y M -Y W |Y0|>YW

[0063] In order to fit the drawing deflection area into the area Re, the deflection offset (X0, Y0) should satisfy the following conditional expression. |X0|+X W <|Y0|-Y W |X0|≦X M -X W |Y0|≦Y M -Y W |X0|>X W

[0064] 13, if a common voltage Vc that is positive with respect to the substrate surface is added to the voltage applied to each electrode of the positioning deflector 28, the drift can be reduced more reliably. This common voltage Vc is a positive voltage V applied to the focus correction lens 32. F It is preferable to set the value equal to or greater than the upper limit of . This allows secondary electrons that pass through the focus correction lens 32 to move to the positioning deflector 28 without decelerating, preventing secondary electrons from stagnation between the focus correction lens 32 and the positioning deflector 28 and improving the accuracy of the beam irradiation position. Although the electrostatic deflector is located close to the focus correction lens, drift due to secondary electron stagnation does not occur. This allows the deflector to be located where the lens magnetic field is present, reducing array distortion caused by deflection. Even if a deflection offset is applied, the increase in array distortion due to deflection offset can be suppressed. Furthermore, as shown in the example in Figure 14, by using two positioning deflectors, one of the positioning deflectors 28 is located close to the focus correction lens, and optimizing the deflection amount and deflection direction of the two positioning deflectors 28, 28', the increase in array distortion due to deflection offset can be further reduced.

[0065] Generally, a ring-shaped earth electrode is placed between the electrodes that apply voltage to the electrostatic deflector and the focus correction lens. However, if such an earth electrode is not placed and the two electrodes (that apply voltage) are placed close to each other, there will be no temporary deceleration (deceleration of secondary electrons) in the short section near the earth electrode, and drift due to retention can be further reduced.

[0066] For example, in the case of a positioning deflector configured with a quadrupole deflector shown in FIG. 7, the voltages applied to the electrodes are as follows: V1=Vc+k(X0+X) V2=Vc+k(Y0+Y) V3=Vc+k(-X0-X) V4=Vc+k(-Y0-Y)

[0067] In the above equation, the left side is the voltage applied to each electrode, the first term (Vc) on the right side is the common voltage, and the second term on the right side (the term multiplied by k) is the deflection voltage already explained. In this specification, a distinction is made between the "applied voltage" to the deflector and the "deflection voltage." The "applied voltage" is the voltage applied to each electrode and is the sum of the common voltage and the deflection voltage. The "deflection voltage" is the voltage that contributes to generating a deflection electric field, which deflects the incident beam and secondary electrons. When no common voltage is applied, the "applied voltage" to the deflector and the "deflection voltage" are the same.

[0068] As shown in FIG. 11, a magnetic deflector 29 may be provided near the electrostatic positioning deflector 28. By exciting the magnetic deflector 29 to generate a deflection offset opposite to that of the positioning deflector 28, part or all of the deflection offset of the incident beam (multi-beam MB) on the substrate surface can be canceled, further reducing distortion and aberration of the incident beam. The excitation amount of the magnetic deflector 29 can be set according to the deflection offset of the positioning deflector 28 and does not need to be changed in conjunction with the deflection positioning operation. Alternatively, the deflection offset of the positioning deflector 28 may be canceled, and then part of the excitation amount may be changed in conjunction with the deflection positioning operation. If the magnetic deflector 29 cancels all of the deflection offset of the positioning deflector 28, the center of the writing deflection area (R1 in FIG. 5) on the substrate surface becomes 0, and no deflection position offset actually occurs. However, as mentioned above, the deflection position and the deflection area themselves on the substrate surface do not directly contribute to drift reduction. In other words, the drift reduction effect can be achieved by satisfying the above-mentioned conditions regarding the deflection voltage. Note that the direction of magnetic field deflection reverses depending on the direction of beam travel, so the deflection of secondary electrons traveling in the opposite direction to the incident beam is not hindered.

[0069] 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]

[0070] 10 Drawing section 12 Electron Optical Tube 14 Electron gun 16 Lighting lens 18 Molded aperture array substrate 20 Blanking aperture array substrate 22 Projection lens 24 Stopping Aperture 26 First objective lens 28 Positioning deflector 29 Magnetic field deflector 30 Second objective lens 32 Focus correction lens 40 Drawing room 42 XY stage 44 PCB 60 Control Unit

Claims

1. forming a multi-charged particle beam that is irradiated onto a substrate to be written; a step of deflecting the multi-charged particle beam to a position to which a predetermined deflection offset is added so as not to include a state in which each deflection voltage applied to each of a plurality of electrodes of an electrostatic positioning deflector is all zero; irradiating the substrate with the multi-charged particle beam; Equipped with a positive common voltage is added to each of the deflection voltages and applied to each electrode of the positioning deflector;

2. 2. The multi-charged particle beam writing method according to claim 1, further comprising the step of deflecting the multi-charged particle beams to a position to which the predetermined deflection offset is added so that the polarity of the voltage of each electrode is constant within each range of the deflection voltage.

3. 3. The multi-charged particle beam writing method according to claim 1, wherein a focus correction lens disposed downstream of the positioning deflector in the traveling direction of the multi-charged particle beam is operated in a positive voltage range.

4. A multi-charged particle beam drawing method as described in Claim 3, wherein the common voltage is equal to or greater than the upper limit value of the positive voltage applied to the focus correction lens.

5. 3. The multi-charged particle beam writing method according to claim 1, wherein a magnetic deflector is used to generate a deflection in a direction opposite to the deflection offset.

6. an electrostatic positioning deflector having a plurality of electrodes and deflecting the multi-charged particle beam irradiated onto a substrate to be drawn; a deflection control circuit that controls the deflection of the multi-charged particle beam to a position to which a predetermined deflection offset is added so that a state in which all of the deflection voltages applied to the plurality of electrodes are zero is not included; Equipped with a positive common voltage is added to each of the deflection voltages and applied to each electrode of the positioning deflector;

7. A multi-charged particle beam drawing device as described in Claim 6, wherein the deflection control circuit controls the deflection of the multi-charged particle beam to a position to which the predetermined deflection offset is added so that the polarity of the voltage of each electrode is constant within the range of each deflection voltage.

8. A focus correction lens arranged downstream of the positioning deflector in the traveling direction of the multi-charged particle beam; a lens control circuit that operates the focus correction lens in a positive voltage range; The multi-charged particle beam writing apparatus according to claim 6 , further comprising:

9. The multi-charged particle beam drawing apparatus of claim 8, wherein the common voltage is equal to or greater than the upper limit of the positive voltage applied to the focus correction lens.

10. A multi-charged particle beam drawing apparatus as described in claim 6, further comprising a magnetic deflector that generates a deflection in a direction opposite to the deflection offset.

11. A multi-charged particle beam drawing device as described in Claim 6, wherein the positioning deflector is composed of a two-stage deflector.

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