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

Abstract

A multi-charged particle beam lithography apparatus according to one aspect of the present invention is characterized by comprising: a beam forming mechanism that forms a multi-charged particle beam; a dose calculation circuit that calculates the dose at each position on a specimen; an additional dose distribution circuit that irradiates a dose excess defect beam, which is a dose excess in the multi-charged particle beam that cannot be subjected to beam dose control and is irradiated, to a position with a dose deficiency for canceling the excess dose within the range where the excess dose diffuses, thereby distributing an additional dose for making a first dose distribution based on the excess dose generated in the specimen into a second dose distribution whose center is located within the range of the first dose distribution and inside a pattern to be lithographed where there is a beam irradiation for canceling the excess dose, to positions within the pattern; a correction circuit that performs correction to reduce the dose increase amount generated at the center of the second dose distribution due to the distribution of the additional dose from the dose irradiated to the center of the second dose distribution or the vicinity of the center of the second dose distribution; and a lithography mechanism that uses the multi-charged particle beam including the dose excess defect beam to lithograph a pattern on the specimen.

Description

Technical Field

[0001] This application claims priority based on JP2020 - 102168 (application number) filed in Japan on June 12, 2020. The content described in JP2020 - 102168 is incorporated into this application.

[0002] One aspect of the present invention relates to a multi - charged particle beam lithography apparatus and a multi - charged particle beam lithography method, and for example, relates to a method for reducing the size deviation of a pattern caused by multi - beam lithography. Background Art

[0003] Lithography technology, which is responsible for the progress of miniaturization of semiconductor devices, is an extremely important process that is the only one to generate patterns in the semiconductor manufacturing process. In recent years, with the high integration of LSIs, the circuit line widths required for semiconductor devices have been miniaturized year by year. Here, electron beam (electron line) lithography technology inherently has excellent resolution, and an electron beam is used to draw a mask pattern on a mask blank.

[0004] For example, there is a lithography apparatus that uses multi - beams. Compared with the case of drawing with a single electron beam, by using multi - beams, a large number of beams can be irradiated at once, so the processing ability can be greatly improved. In such a multi - beam type lithography apparatus, for example, an electron beam emitted from an electron gun forms multi - beams through a mask having a plurality of holes, is blanked and controlled respectively, and each unobstructed beam is reduced in size by an optical system, whereby the mask image is reduced and irradiated to a desired position on a specimen by being deflected by a deflector.

[0005] In multi - beam lithography, the dose irradiated from each beam is controlled by the irradiation time. However, due to a failure of the blanking control mechanism or the like, it is difficult to control the irradiation time, and a defective beam that irradiates a specimen with a dose that is excessive compared to the desired dose may be generated. For example, a constantly - on beam is cited as a representative example. If an excessive dose is irradiated to the specimen, there is a problem of generating a shape error in the pattern formed on the specimen. In response to this problem, the following method has been proposed: irradiation is performed in such a way that the corresponding share dose is reduced from the doses of the surrounding beam groups, so that the same dose as the excessive dose of the defective beam is shared by the beam groups around the defective beam. However, in the case where a constantly - on beam is irradiated at a position outside the end of the pattern to be drawn, most of the surrounding beam groups are located outside the end of the pattern, and the position outside the pattern is a position where the original irradiation amount is zero, so there is a problem that it is difficult to share the excessive dose by the surrounding beam groups (for example, refer to Patent Document 1).

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-021919 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] One aspect of the present invention provides an apparatus and a method that can reduce shape errors of a pattern caused by a defective beam by a simple method when, in multi-beam lithography, a defective beam with an excessive dose is irradiated to a position outside the end of the pattern.

[0011] Means for Solving the Problems

[0012] A multi-charged particle beam lithography apparatus according to one aspect of the present invention is characterized by comprising:

[0013] a beam forming mechanism that forms a multi-charged particle beam;

[0014] a dose calculation circuit that calculates the dose at each position on a specimen;

[0015] an additional dose distribution circuit that irradiates a defective beam with an excessive dose, which cannot be dose-controlled in the multi-charged particle beam, to a position with a dose deficiency for canceling the excessive dose within the range where the excessive dose diffuses, thereby distributing an additional dose for making a first dose distribution based on the excessive dose generated on the specimen into a second dose distribution whose center is located within the range of the first dose distribution and inside the pattern to be drawn where there is a beam irradiation for canceling the excessive dose, to a position within the pattern;

[0016] a correction circuit that performs correction to reduce the dose increase amount generated at the center of the second dose distribution due to the distribution of the additional dose, from the dose irradiated to the center of the second dose distribution or the vicinity of the center of the second dose distribution; and

[0017] a drawing mechanism that uses the multi-charged particle beam including the defective beam with an excessive dose to draw a pattern on a specimen.

[0018] A multi-charged particle beam lithography method according to one aspect of the present invention is characterized in that

[0019] a multi-charged particle beam is formed,

[0020] the dose at each position on a specimen is calculated,

[0021] By irradiating a position with insufficient dose that is used to cancel out the excess dose within the range where the excess dose spreads, an additional dose for making a first dose distribution based on the excess dose generated in the specimen into a second dose distribution whose center is located within the range of the first dose distribution and inside the pattern of the object to be depicted where there is a beam irradiation for canceling out the excess dose is assigned to positions within the pattern.

[0022] Correction is performed to reduce the dose increase amount generated at the center of the second dose distribution due to the assignment of the additional dose from the dose irradiated to the center of the second dose distribution or the vicinity of the center of the second dose distribution.

[0023] A pattern is depicted on a specimen using a multi-charged particle beam including a dose excess defect beam.

[0024] Advantages of the Invention

[0025] According to one aspect of the present invention, in multi-beam lithography, when irradiating a dose excess defect beam to a position outside the end of a pattern, the shape error of the pattern caused by the defect beam can be reduced by a simple method. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a conceptual diagram showing the configuration of a lithography apparatus according to Embodiment 1.

[0027] Figure 2 It is a conceptual diagram showing the configuration of a shaping aperture array substrate according to Embodiment 1.

[0028] Figure 3 It is a cross-sectional view showing the configuration of a blanking aperture array mechanism according to Embodiment 1.

[0029] Figure 4 It is a top view conceptual diagram showing a part of the configuration within the diaphragm area of the blanking aperture array mechanism according to Embodiment 1.

[0030] Figure 5 It is a diagram showing an example of a separate blanking mechanism according to Embodiment 1.

[0031] Figure 6 It is a conceptual diagram for explaining an example of the lithography operation according to Embodiment 1.

[0032] Figure 7 It is a diagram showing an example of the irradiation area of a multi-beam and a pixel to be depicted according to Embodiment 1.

[0033] Figure 8 It is a diagram for explaining an example of the multi-beam lithography method according to Embodiment 1.

[0034] Figure 9It is a flowchart showing the main process steps of the drawing method of Embodiment 1.

[0035] Figure 10 It is a diagram for explaining the position offset and position offset periodicity of the beam in Embodiment 1.

[0036] Figure 11 It is a diagram for explaining an example of the position offset correction method in Embodiment 1.

[0037] Figure 12 It is a diagram showing an example of the dose of each path in multiple drawing using a beam without position offset in Embodiment 1.

[0038] Figure 13 It is a diagram showing an example of the relationship between the control grid, the irradiation position of the beam, and the pattern edge in Embodiment 1.

[0039] Figure 14 It is a diagram for explaining the beam distribution in Embodiment 1.

[0040] Figure 15 It is a diagram showing an example of the peripheral beams of a defective beam in the central part of the pattern in Embodiment 1.

[0041] Figure 16 It is a diagram showing an example of the peripheral beams of a defective beam on or near the pattern edge in Embodiment 1.

[0042] Figure 17 It is a diagram showing an example of the relationship between the dose curve and the pixels in Embodiment 1.

[0043] Figure 18 It is a diagram showing an example of the distribution of additional dose and the center of gravity position in Embodiment 1.

[0044] Figure 19 It is a diagram showing an example of the dose distribution based on excess dose, the dose distribution based on additional dose, and the combined dose distribution of both in Embodiment 1. Detailed implementation mode

[0045] Hereinafter, in the embodiment, as an example of a charged particle beam, the configuration using an electron beam will be described. However, the charged particle beam is not limited to an electron beam, and may also be a beam of charged particles such as an ion beam.

[0046] [Embodiment 1]

[0047] Figure 1 It is a conceptual diagram showing the configuration of the drawing apparatus in Embodiment 1. In Figure 1In this case, the drawing apparatus 100 includes a drawing mechanism 150 and a control system circuit 160. The drawing apparatus 100 is an example of a multi-charged particle beam drawing apparatus. The drawing mechanism 150 includes an electron column 102 (multi-electron beam column) and a drawing chamber 103. Inside the electron column 102, an electron gun 201, an illumination lens 202, a shaping aperture array substrate 203, a blanking aperture array mechanism 204, a reduction lens 205, a limiting aperture substrate 206, an objective lens 207, a deflector 208, and a deflector 209 are arranged. Inside the drawing chamber 103, an XY stage 105 is arranged. On the XY stage 105, a specimen 101 is arranged. The specimen 101 is a resist-coated mask blank or the like that becomes a drawing target substrate during drawing. The specimen 101 includes an exposure mask for manufacturing a semiconductor device or a semiconductor substrate (silicon wafer) for manufacturing a semiconductor device. On the XY stage 105, a mirror 210 for measuring the position of the XY stage 105 is also arranged. On the XY stage 105, a Faraday cup 106 is also arranged.

[0048] The control system circuit 160 includes a control computer 110, a memory 112, a deflection control circuit 130, digital / analog conversion (DAC) amplifier units 132 and 134, a stage position detector 139, and storage devices 140, 142, and 144 such as a disk device. The control computer 110, the memory 112, the deflection control circuit 130, the DAC amplifier units 132 and 134, the stage position detector 139, and the storage devices 140, 142, and 144 are interconnected via a bus (not shown). The DAC amplifier units 132 and 134 and the blanking aperture array mechanism 204 are connected to the deflection control circuit 130. The output of the DAC amplifier unit 132 is connected to the deflector 209. The output of the DAC amplifier unit 134 is connected to the deflector 208. The deflector 208 is composed of electrodes with four or more poles, and each electrode is controlled by the deflection control circuit 130 via the DAC amplifier 134. The deflector 209 is composed of electrodes with four or more poles, and each electrode is controlled by the deflection control circuit 130 via the DAC amplifier 132. The stage position detector 139 irradiates a laser beam onto the mirror 210 on the XY stage 105 and receives the reflected light from the mirror 210. Then, the position of the XY stage 105 is measured using the principle of laser interference using the information of this reflected light.

[0049] The rasterization unit 50, dose map creation unit 52, beam position offset map creation unit 54, detection unit 56, modulation rate calculation unit 59, dose map creation unit 60, dose allocation processing unit 61, determination unit 62, determination unit 63, surrounding pixel determination unit 64 with large dose, allocation unit 65, elimination dose calculation unit 66, correction unit 67, determination unit 68, irradiation time calculation unit 72, and drawing control unit 74 are configured in the control computer 110. Each of the "~ units" such as the rasterization unit 50, dose map creation unit 52, beam position offset map creation unit 54, detection unit 56, modulation rate calculation unit 59, dose map creation unit 60, dose allocation processing unit 61, determination unit 62, determination unit 63, surrounding pixel determination unit 64 with large dose, allocation unit 65, elimination dose calculation unit 66, correction unit 67, determination unit 68, irradiation time calculation unit 72, and drawing control unit 74 has a processing circuit. Such a processing circuit includes, for example, a circuit, a computer, a processor, a circuit board, a quantum circuit, or a semiconductor device. Each of the "~ units" may use a common processing circuit (the same processing circuit), or may also use different processing circuits (different processing circuits). Information input and output to and from the rasterization unit 50, dose map creation unit 52, beam position offset map creation unit 54, detection unit 56, modulation rate calculation unit 59, dose map creation unit 60, dose allocation processing unit 61, determination unit 62, determination unit 63, surrounding pixel determination unit 64 with large dose, allocation unit 65, elimination dose calculation unit 66, correction unit 67, determination unit 68, irradiation time calculation unit 72, and drawing control unit 74, as well as information during calculation, is stored in the memory 112 each time.

[0050] In addition, drawing data is input from the outside of the drawing device 100 and stored in the storage device 140. In the drawing data, information on a plurality of graphic patterns for drawing is usually defined. Specifically, for each graphic pattern, a graphic code, coordinates, dimensions, etc. are defined.

[0051] Here, in Figure 1 the configurations required for describing the first embodiment are described. For the drawing device 100, other necessary configurations can generally be provided.

[0052] Figure 2 is a conceptual diagram showing the configuration of the shaping aperture array substrate of the first embodiment. In Figure 2 the shaping aperture array substrate 203, holes (openings) 22 of p columns in the longitudinal direction (y direction) × q columns in the lateral direction (x direction) (p, q ≥ 2) are formed in a matrix at a prescribed arrangement pitch. In Figure 2Among them, for example, holes 22 of 512×512 columns are formed in the vertical and horizontal directions (x and y directions). Each hole 22 is formed as a rectangle with the same size and shape. Alternatively, they can also be circles with the same diameter. The formed-aperture array substrate 203 (beam forming mechanism) forms multiple beams 20. Specifically, a part of the electron beam 200 passes through the above-mentioned multiple holes 22 respectively, thereby forming multiple beams 20. In addition, the arrangement method of the holes 22 is not limited to the case where they are arranged in a grid pattern in the vertical and horizontal directions as shown in FIG. 2. For example, the holes in the k-th column and the (k + 1)-th column in the vertical direction (y direction) can also be arranged with an offset of size a in the horizontal direction (x direction). Similarly, the holes in the (k + 1)-th column and the (k + 2)-th column in the vertical direction (y direction) can also be arranged with an offset of size b in the horizontal direction (x direction).

[0053] Figure 3 It is a cross-sectional view showing the configuration of the blanking aperture array mechanism of Embodiment 1.

[0054] Figure 4 It is a top view conceptual diagram showing a part of the configuration within the diaphragm area of the blanking aperture array mechanism of Embodiment 1. In addition, in Figure 3 and Figure 4 it is described without making the positional relationship between the control electrode 24, the counter electrode 26, the control circuit 41, and the pad 43 consistent. As Figure 3 shown, the blanking aperture array mechanism 204 disposes a semiconductor substrate 31 made of silicon or the like on the support table 33. The central part of the substrate 31 is cut from the back side, for example, and processed into a diaphragm area 330 (first area) with a relatively thin film thickness h. The periphery surrounding the diaphragm area 330 becomes an outer peripheral area 332 (second area) with a relatively thick film thickness H. The upper surface of the diaphragm area 330 and the upper surface of the outer peripheral area 332 are formed at the same height position or substantially the same height position. The substrate 31 is held on the support table 33 at the back of the outer peripheral area 332. The central part of the support table 33 is open, and the position of the diaphragm area 330 is located in the open area of the support table 33.

[0055] In the diaphragm area 330, at positions corresponding to the respective holes 22 of the formed-aperture array substrate 203 shown in Figure 2 through holes 25 (openings) for allowing the respective beams of the multiple beams 20 to pass through are formed. In other words, a plurality of through holes 25 for allowing the beams corresponding to the multiple beams 20 using electron rays to pass through are formed in an array in the diaphragm area 330 of the substrate 31. And, on the diaphragm area 330 of the substrate 31 and at positions facing each other across the corresponding through holes 25 among the multiple through holes 25, a plurality of electrode pairs each having two electrodes are respectively arranged. Specifically, as Figure 3 and Figure 4As shown, a pair of a blanking deflection control electrode 24 and a counter electrode 26 (blanker: blanking deflector) are respectively arranged across the through hole 25 on the diaphragm area 330 at positions near each through hole 25. Further, a control circuit 41 (logic circuit) for applying a deflection voltage to the control electrode 24 for each through hole 25 is arranged inside the substrate 31 and near each through hole 25 on the diaphragm area 330. The counter electrode 26 for each beam is grounded.

[0056] Further, as Figure 4 shown, each control circuit 41 is connected with parallel wirings of n bits (e.g., 10 bits) for control signals. In addition to the parallel wirings of n bits for control signals, each control circuit 41 is also connected with a clock signal line, a read signal, a shot signal, a power supply wiring, etc. The clock signal line, the read signal, the shot signal, the power supply wiring, etc. can also use a part of the parallel wirings. For each of the beams constituting the multi-beam, an individual blanking mechanism 47 is constituted by the control electrode 24, the counter electrode 26, and the control circuit 41. Further, in Figure 3 the example, the control electrode 24, the counter electrode 26, and the control circuit 41 are arranged in the diaphragm area 330 where the film thickness of the substrate 31 is relatively thin. However, it is not limited thereto. Further, a plurality of control circuits 41 formed in an array in the diaphragm area 330 are grouped, for example, by the same row or the same column, as Figure 4 shown, the control circuits 41 in the group are connected in series. Then, the signal from the pad 43 arranged for each group is transmitted to the control circuits 41 in the group. Specifically, a shift register (not shown) is arranged in each control circuit 41. For example, the shift registers in the control circuits 41 of the beams in the same row among p×q multi-beams are connected in series. And, for example, the control signals of the beams in the same row of p×q multi-beams are sent in sequence, and for example, the control signals of each beam are stored in the corresponding control circuit 41 through p clock signals.

[0057] Figure 5 FIG. is a diagram showing an example of the individual blanking mechanism of Embodiment 1. In Figure 5 it, an amplifier 46 (an example of a switching circuit) is arranged in the control circuit 41. In Figure 5In the example, as an example of the amplifier 46, a CMOS (Complementary MOS) inverter circuit is provided. The CMOS inverter circuit is connected to a positive potential (Vdd: blanking potential: first potential) (e.g., 5V) (first potential) and a ground potential (GND: second potential). The output line (OUT) of the CMOS inverter circuit is connected to the control electrode 24. On the other hand, the counter electrode 26 is applied with the ground potential. And on the substrate 31, at positions opposed to the counter electrodes 26 respectively corresponding to the plurality of counter electrodes 26 through the plurality of vias 25 respectively corresponding to the plurality of vias 25, a plurality of control electrodes 24 capable of selectively applying the blanking potential and the ground potential are provided.

[0058] Either an L (low) potential lower than the threshold voltage (e.g., ground potential) or an H (high) potential equal to or higher than the threshold voltage (e.g., 1.5V) is applied as a control signal to the input (IN) of the CMOS inverter circuit. In the first embodiment, in a state where the L potential is applied to the input (IN) of the CMOS inverter circuit, the output (OUT) of the CMOS inverter circuit becomes the positive potential (Vdd), and a corresponding one of the multi-beams 20 is deflected by the electric field generated by the potential difference between the counter electrode 26 and the ground potential, and is blocked by the aperture-limiting substrate 206, thereby controlling the beam to be cut off. On the other hand, in a state where the H potential is applied to the input (IN) of the CMOS inverter circuit (active state), the output (OUT) of the CMOS inverter circuit becomes the ground potential, the potential difference between the counter electrode 26 and the ground potential disappears, and a corresponding one of the multi-beams 20 is not deflected. Therefore, through the aperture-limiting substrate 206, the beam is controlled to be turned on.

[0059] A corresponding one of the multi-beams 20 passing through each via is deflected by the voltage applied to the two control electrodes 24 and the counter electrode 26 that are independently paired. The blanking control is performed through this deflection. Specifically, the group of the control electrode 24 and the counter electrode 26 selectively blanks and deflects the corresponding beam of the multi-beam 20 by the potentials switched by the CMOS inverter circuit that becomes the corresponding switching circuit. In this way, the plurality of blankers perform blanking deflection of the corresponding beams in the multi-beam 20 after passing through the plurality of holes 22 (openings) of the aperture-forming array substrate 203.

[0060] Figure 6 It is a conceptual diagram for explaining an example of the drawing operation of the first embodiment. As Figure 6As shown, the drawing area 30 of the sample 101 is virtualy divided into a plurality of long strip areas 32 with a predetermined width, for example, in the y direction. First, the XY worktable 105 is moved and adjusted so that the irradiation area 34 that can be irradiated by the emission of the multi-beam 20 once is located at the left end or further to the left of the first strip area 32, and drawing is started. When drawing the first strip area 32, the XY worktable 105 is moved, for example, in the -x direction, and drawing is performed relatively in the x direction. The XY worktable 105 moves continuously, for example, at a constant speed. After the drawing of the first strip area 32 is completed, the worktable position is moved in the -y direction and adjusted so that the irradiation area 34 is relatively located at the right end or further to the right of the second strip area 32 in the y direction. This time, the XY worktable 105 is moved, for example, in the x direction, and drawing is performed in the -x direction in the same manner. By depicting in the x direction in the third strip region 32 and in the -x direction in the fourth strip region 32, the depiction is performed while changing the direction alternately, thereby shortening the depiction time. However, this is not limited to the case where the depiction is performed while changing the direction alternately, and the depiction may be performed in the same direction when depicting each strip region 32. In one emission, multiple emission patterns are formed at one time using multiple beams formed by each hole 22 of the forming aperture array substrate 203, with the maximum number being the same as the number of holes 22 formed in the forming aperture array substrate 203. In addition, in Figure 6 In the example of FIG. 1 , the strip regions 32 are depicted one by one, but the present invention is not limited thereto. Even if multiple depictions are performed to depict the same region multiple times, it is also appropriate. When multiple depictions are performed, it is preferred to set the strip regions 32 of each path while shifting the positions.

[0061] Figure 7 FIG. 1 is a diagram showing an example of a multi-beam irradiation area and a drawing target pixel according to Embodiment 1. Figure 7 In the strip region 32, for example, a plurality of control grids 27 (design grids) are arranged in a grid-like manner with a beam size pitch of the multi-beam 20 on the surface of the sample 101. For example, the control grids 27 are preferably arranged at a pitch of about 10 nm. Such a plurality of control grids 27 become the designed irradiation positions of the multi-beam 20. The arrangement pitch of the control grids 27 is not limited to the beam size, and can be configured with any size that can be controlled as the deflection position of the deflector 209 regardless of the beam size. Furthermore, a plurality of pixels 36 that are virtually divided in a grid-like manner with the same size as the arrangement pitch of the control grids 27 as the center are set. Each pixel 36 becomes the irradiation unit area of ​​each beam in the multi-beam. In Figure 7In the example, it is shown that the depicted area of the specimen 101 is divided into a plurality of strip-shaped areas 32 in the y direction, for example, with a width dimension substantially the same as the size of the irradiation area 34 (depicted area) that can be irradiated by the irradiation of the multi-beam 20 once. The x-direction dimension of the irradiation area 34 can be defined by the value obtained by multiplying the beam pitch in the x direction of the multi-beam 20 by the number of beams in the x direction. The y-direction dimension of the irradiation area 34 can be defined by the value obtained by multiplying the beam pitch in the y direction of the multi-beam 20 by the number of beams in the y direction. Additionally, the width of the strip-shaped area 32 is not limited to this. It is preferably a size that is n times (n is an integer of 1 or more) the size of the irradiation area 34. In Figure 7 the example, for example, the illustration of a multi-beam of 512×512 columns is omitted and shown as a multi-beam of 8×8 columns. And, within the irradiation area 34, a plurality of pixels 28 (depicted positions of the beams) that can be irradiated by the emission of the multi-beam 20 once are shown. In other words, the pitch between adjacent pixels 28 is the pitch between the respective beams of the multi-beam in design. In Figure 7 the example, a sub-irradiation area 29 is formed by an area surrounded by the beam pitch. In Figure 7 the example, it is shown that each sub-irradiation area 29 is composed of 4×4 pixels.

[0062] Figure 8 is a diagram for explaining an example of the multi-beam depiction method of Embodiment 1. In Figure 8 it, a part of the sub-irradiation area 29 depicted by the beams of the strip-shaped area 32 shown in Figure 7 with the coordinates (1, 3), (2, 3), (3, 3), ……, (512, 3) of the third row in the y direction among the multi-beams is shown. In Figure 8 the example, for example, it is shown that 4 pixels are depicted (exposed) during the period when the XY stage 105 moves a distance of 8 beam pitches. During the period of depicting (exposing) these 4 pixels, the entire multi-beam 20 is deflected together by the deflector 208, thereby causing the irradiation area 34 to follow the movement of the XY stage 105 so that the relative position of the irradiation area 34 with respect to the specimen 101 does not shift due to the movement of the XY stage 105. In other words, tracking control is performed. In Figure 8 the example, it is shown that: 4 pixels are depicted (exposed) during the period of moving a distance of 8 beam pitches, thereby implementing one tracking cycle.

[0063] Specifically, the stage position detector 139 irradiates a laser beam onto the mirror 210 and receives the reflected light from the mirror 210, thereby measuring the position of the XY stage 105. The measured position of the XY stage 105 is output to the control computer 110. Inside the control computer 110, the drawing control section 74 outputs such position information of the XY stage 105 to the deflection control circuit 130. Inside the deflection control circuit 130, in accordance with the movement of the XY stage 105, the deflection amount data (tracking deflection data) for performing beam deflection to follow the movement of the XY stage 105 is calculated. The tracking deflection data as a digital signal is output to the DAC amplifier 134, and the DAC amplifier 134 converts the digital signal into an analog signal and then amplifies it, and applies it as a tracking deflection voltage to the deflector 208.

[0064] Then, during the maximum drawing time Ttr within the irradiation time of each beam of the multi-beams during this emission, the drawing mechanism 150 irradiates each control grid 27 with a beam corresponding to each of the on-beams in the multi-beams 20 within the drawing time (irradiation time or exposure time) corresponding to each control grid 27.

[0065] In Figure 8 the example of, through the beam (1) at the coordinates (1, 3), from the time t = 0 to t = the maximum drawing time Ttr, the control grid 27 of, for example, the first pixel 36 from the right in the lowermost row of the sub-irradiation area 29 of interest is irradiated with the beam of the first emission. Thus, this pixel is irradiated with the beam for the desired irradiation time. During the period from the time t = 0 to t = Ttr, the XY stage 105 moves, for example, by an amount of two beam pitches in the -x direction. During this period, the tracking operation continues.

[0066] After the maximum drawing time Ttr of this emission has elapsed since the start of the beam irradiation of this emission, while continuing the beam deflection for tracking control through the deflector 208, different from the beam deflection for tracking control, the multi-beams 20 are deflected together through the deflector 209 to shift the drawing position (previous drawing position) of each beam to the next drawing position (this time's drawing position) of each beam. In Figure 8 the example of, at the time point when it becomes the time t = Ttr, the drawing object control grid 27 is shifted from the control grid 27 of the first pixel 36 from the right in the lowermost row of the sub-irradiation area 29 of interest to the control grid 27 of the first pixel 36 from the right in the second row from the bottom. During this period, since the XY stage 105 also moves at a constant speed, the tracking operation continues.

[0067] Then, while continuing the tracking control, beams corresponding to the turned-on beams in the multi-beam 20 are irradiated to the drawing positions of the shifted beams at the drawing times respectively corresponding to the maximum drawing time Ttr of the emission. In Figure 8 the example of Figure 8 , the beam passing through the coordinates (1, 3) (beam 1) irradiates the control grid 27 of, for example, the second pixel from the bottom and the first pixel from the right in the sub-irradiation region 29 of interest, which is the beam for the second emission, during the period from time t = Ttr to t = 2Ttr. During the period from time t = Ttr to t = 2Ttr, the XY stage 105 moves, for example, by an amount of two beam pitches in the -x direction. During this period, the tracking operation is continued.

[0068] In Figure 8 the example of Figure 8 , at the time point when t = 2Ttr, the multi-beam is deflected all at once by the deflector 209, and the drawing object control grid 27 is shifted from the control grid 27 of the second pixel from the bottom and the first pixel from the right in the sub-irradiation region 29 of interest to the control grid 27 of the third pixel from the bottom and the first pixel from the right. During this period, the XY stage 105 also moves, so the tracking operation is continued. Then, the beam passing through the coordinates (1, 3) (beam 1) irradiates the control grid 27 of, for example, the third pixel from the bottom and the first pixel from the right in the sub-irradiation region 29 of interest, which is the beam for the third emission, during the period from time t = 2Ttr to t = 3Ttr. Thus, the control grid 27 of this pixel 36 is irradiated with the beam for the desired irradiation time.

[0069] During the period from time t = 2Ttr to t = 3Ttr, the XY stage 105 moves, for example, by an amount of two beam pitches in the -x direction. During this period, the tracking operation is continued. At the time point when t = 3Ttr, the multi-beam is deflected all at once by the deflector 209, and the drawing object pixel is shifted from the control grid 27 of the third pixel from the bottom and the first pixel from the right in the sub-irradiation region 29 of interest to the control grid 27 of the fourth pixel from the bottom and the first pixel from the right. During this period, the XY stage 105 also moves, so the tracking operation is continued.

[0070] Then, the beam passing through the coordinates (1, 3) (beam 1) irradiates the control grid 27 of, for example, the fourth pixel from the bottom and the first pixel from the right in the sub-irradiation region 29 of interest, which is the beam for the fourth emission, during the period from time t = 3Ttr to t = 4Ttr. Thus, the control grid 27 of this pixel 36 is irradiated with the beam for the desired irradiation time.

[0071] During the period from time t = 3Ttr to t = 4Ttr, the XY stage 105 moves, for example, by an amount of 2 beam pitches in the -x direction. During this period, the tracking operation continues. As described above, the drawing of the first pixel column from the right of the sub-illumination area 29 is completed.

[0072] In Figure 8 's example, after irradiating the corresponding beams to the drawing positions of the respective beams shifted 3 times from the initial position, the DAC amplification unit 134 resets the beam deflection for tracking control, thereby returning the tracking position to the tracking start position where the tracking control starts. In other words, the tracking position is returned in the direction opposite to the stage movement direction. In Figure 8 's example, at the time point when it becomes time t = 4Ttr, the relay of the sub-illumination area 29 to be concerned is released, and the beam returns to the sub-illumination area 29 shifted by an amount of 8 beam pitches in the x direction. In addition, in Figure 8 's example, the beam (1) at the coordinates (1, 3) has been described, but for the beams at other coordinates, the respective corresponding sub-illumination areas 29 are drawn in the same manner. That is, the drawing of the first pixel column from the right of the corresponding sub-illumination area 29 of the beam at the coordinates (n, m) is completed at the time point of t = 4Ttr. For example, the drawing of the first pixel column from the right of the sub-illumination area 29 adjacent to the sub-illumination area 29 used for the beam (1) in the -x direction of the beam (2) at the coordinates (2, 3) is completed. Figure 7 's beam (1) is completed.

[0073] In addition, since the drawing of the first pixel column from the right of each sub-illumination area 29 is completed, after the tracking reset, in the next tracking cycle, first, the deflector 209 deflects so that the drawing positions of the beams corresponding to the control grids 27 of the second row from the bottom and the second pixel from the right of each sub-illumination area 29 coincide (shift).

[0074] As described above, in the same tracking cycle, while controlling the irradiation area 34 to be in the same relative position with respect to the specimen 101 by the deflector 208, each emission is performed while shifting one control grid 27 (pixel 36) at a time by the deflector 209. Then, after one cycle of the tracking cycle ends, the tracking position of the irradiation area 34 is returned, and then, as Figure 6 shown in the lower part, for example, the first emission position is made to coincide with the position shifted by one control grid (one pixel), and each emission is performed while shifting one control grid (one pixel) at a time by the deflector 209 while performing the next tracking control. In the drawing of the bar area 32, by repeating this operation, in the case of the irradiation areas 34a to 34o, the position of the irradiation area 34 moves sequentially, and the drawing of this bar area is performed.

[0075] When depicting the specimen 101 by means of the multi-beam 20, as described above, during the tracking operation by the deflector 208, while following the movement of the XY stage 105, the multi-beam 20 that will become the emitted beam is sequentially and continuously irradiated one control grid (one pixel) at a time by moving the beam deflection position based on the deflector 209. Then, it is determined which beam of the multi-beam irradiates which control grid 27 (pixel 36) on the specimen 101 according to the depiction order. Then, using the beam pitch between the beams adjacent to each other in the x and y directions of the multi-beam, the area of the beam pitch (x direction) × beam pitch (y direction) between the beams adjacent to each other in the x and y directions on the surface of the specimen 101 is composed of an area of n×n pixels (sub-irradiation area 29). For example, during one tracking operation, when the XY stage 105 moves by the beam pitch (x direction) in the -x direction, as described above, while shifting the irradiation position by one beam in the y direction, n control grids (n pixels) are depicted. Alternatively, n control grids (n pixels) can also be depicted while shifting the irradiation position by one beam in the x direction or the oblique direction. The other n pixels within the same area of n×n pixels are depicted with n pixels in the same way by a beam different from the above-mentioned beam during the next tracking operation. Thus, all the pixels within an area of n×n pixels are depicted by different beams, n pixels at a time, during n tracking operations. The same operation is also performed on other areas of n×n pixels within the irradiation area of the multi-beam, and the depiction is carried out in the same way.

[0076] Next, the operation of the depiction mechanism 150 in the depiction apparatus 100 will be described. The electron beam 200 emitted from the electron gun 201 (emission source) illuminates the entire shaping aperture array substrate 203 through the illumination lens 202. A plurality of rectangular holes 22 (openings) are formed in the shaping aperture array substrate 203, and the electron beam 200 illuminates the area including all the plurality of holes 22. Each part of the electron beam 200 irradiated at the positions of the plurality of holes 22 passes through the plurality of holes 22 of such a shaping aperture array substrate 203 respectively, thereby forming, for example, a plurality of electron beams (multi-beam 20) in a rectangular shape. Such a multi-beam 20 passes through the corresponding blankers (first deflectors: individual blanking mechanisms) within the blanking aperture array mechanism 204. Each of these blankers deflects the electron beam passing through it alone (performs blanking deflection).

[0077] The multi-beams 20 that have passed through the blanking aperture array mechanism 204 are reduced by the reduction lens 205 and travel toward the hole formed at the center of the limiting aperture substrate 206. Here, the position of the electron beam deflected by the blanker of the blanking aperture array mechanism 204 in the multi-beams 20 deviates from the hole at the center of the limiting aperture substrate 206 and is blocked by the limiting aperture substrate 206. On the other hand, the electron beam not deflected by the blanker of the blanking aperture array mechanism 204 passes through the hole at the center of the limiting aperture substrate 206 as shown in Figure 1 . By the opening / closing of this individual blanking mechanism 47, blanking control is performed to control the opening / closing of the beam. In this way, the limiting aperture substrate 206 blocks each beam in the state where the beam is deflected by the individual blanking mechanism 47 to the beam cutoff state. Then, for each beam, a beam for one-time emission is formed by using the beam that has passed through the limiting aperture substrate 206 and is formed from the time when the beam is turned on to the time when the beam is turned off. The multi-beams 20 that have passed through the limiting aperture substrate 206 are focused by the objective lens 207 to form a pattern image with a desired reduction ratio. Each beam (the entire multi-beams 20 that have passed through) that has passed through the limiting aperture substrate 206 is deflected in the same direction by the deflectors 208 and 209 and irradiated to each irradiation position on the specimen 101 of each beam. The multi-beams 20 for one-time irradiation are ideally arranged at intervals obtained by multiplying the arrangement pitch of the plurality of holes 22 of the shaping aperture array substrate 203 by the above-mentioned desired reduction ratio.

[0078] Figure 9 FIG. is a flowchart showing the main process steps of the drawing method according to Embodiment 1. In Figure 9 , the drawing method of Embodiment 1 implements a series of processes such as a beam position offset measurement process (S102), a dose calculation process (S104), a defective beam detection process (S110), a modulation rate calculation process (S112), a shortage defective beam pixel determination process (S113), a dose calculation process for each path (S114), a dose excess defective beam pixel determination process (S116), a determination process (S120), a dose distribution process (S122), a determination process for surrounding pixels with a large dose (S130), an additional dose distribution process (S132), an erasure dose calculation process (S134), an erasure correction process (S136), a determination process (S138), an irradiation time calculation process (S140), and a drawing process (S142).

[0079] As the beam position offset measurement process (S102), the drawing apparatus 100 measures the position offset amount by which the irradiation position of each beam of the multi-beams 20 on the surface of the specimen 101 deviates from the corresponding control grid 27.

[0080] Figure 10This is a diagram for explaining the position deviation and position deviation periodicity of the beams in Embodiment 1. In the multi-beam 20, as shown in Figure 10 (a) thereof, due to the characteristics of the optical system, deformation occurs in the exposure field. Due to this deformation, etc., the actual irradiation position 39 of each beam deviates from the irradiation position 37 in the case of irradiating an ideal grid. Therefore, in Embodiment 1, the position deviation amount of the actual irradiation position 39 of each beam is measured. Specifically, the position of the resist pattern generated by irradiating the evaluation substrate coated with resist with the multi-beam 20 and developing the evaluation substrate is measured by using a position detector, thereby measuring the position deviation amount of each beam. In the emission size of each beam, if it is difficult to measure the size of the resist pattern at the irradiation position of each beam by using a position detector, then as long as a graphic pattern (such as a rectangular pattern) with a size that can be measured by the position detector is drawn by each beam, the edge positions on both sides of the graphic pattern (resist pattern) are measured, and the position deviation amount of the target beam is measured according to the difference between the intermediate position between the two edges and the intermediate position of the graphic pattern in design. Then, the position deviation amount data of the irradiation positions of the respective beams obtained is input to the drawing device 100 and stored in the storage device 144. In addition, in multi-beam drawing, while shifting the irradiation area 34 within the bar-shaped area 32, for example, in the drawing order described in Figure 8 , as shown in the lower part of Figure 6 , in the drawing of the bar-shaped area 32, in the case of the irradiation areas 34a to 34o, the position of the irradiation area 34 moves sequentially. Whenever the irradiation area 34 moves, periodicity occurs in the position deviation of each beam. Or, if it is the case of the drawing order in which each beam irradiates all the pixels 36 within the corresponding sub-irradiation area 29, then as shown in Figure 10 (b), in each unit area 35 (35a, 35b,...) having at least the same size as the irradiation area 34, periodicity occurs in the position deviation of each beam. Therefore, if the position deviation amount of each beam in one irradiation area 34 is measured, the measurement result can be reused. In other words, for each beam, as long as the position deviation amount in each pixel 36 within the corresponding sub-irradiation area 29 can be measured.

[0081] Then, the beam position deviation mapping creation unit 54 first creates a beam position deviation mapping (1) that defines the beam array unit, that is, the position deviation amount of each beam within the irradiation area 34. Specifically, as long as the beam position deviation mapping creation unit 54 reads out the position deviation amount data of the irradiation positions of the respective beams from the storage device 144 and creates the beam position deviation mapping (1) using such data as the mapping values.

[0082] Next, the beam position offset map creation unit 54 creates a beam position offset map (2) in the control grid 27 of each pixel 36 within the bar region 32. For example, as Figure 8 described, which beam irradiates the control grid 27 of each pixel 36 within the bar region 32 is determined according to the drawing order. Therefore, the beam position offset map creation unit 54 determines, according to the drawing order, the beam responsible for irradiating each control grid 27 of each pixel 36 within the bar region 32, and calculates the position offset amount of this beam. Then, the beam position offset map creation unit 54 uses the position offset amount of the irradiation position of the beam to each control grid 27 as a map value to create a beam position offset map (2) in bar units. As described above, since the position offset of each beam is periodic, it is only necessary to use the value of the beam position offset map (1) in beam array units to create the beam position offset map (2) in bar units. The created beam position offset map (2) is stored in the storage device 144.

[0083] As the dose calculation process (S104), first, the rasterization unit 50 reads out the drawing data from the storage device 140, and calculates the pattern area density ρ' within each pixel 36 for each pixel 36. For example, this process is performed for each bar region 32.

[0084] Next, the dose map creation unit 52 first hypothetically divides the drawing region (here, for example, the bar region 32) into a plurality of adjacent grid regions (adjacent effect correction calculation grid regions) in a grid pattern with a specified size. The size of the adjacent grid region is preferably set to about 1 / 10 of the influence range of the adjacent effect, for example, about 1 μm. The dose map creation unit 52 reads out the drawing data from the storage device 140, and calculates the pattern area density ρ of the pattern arranged within each adjacent grid region for each adjacent grid region.

[0085] Next, the dose map creation unit 52 calculates, for each adjacent grid region, an adjacent effect correction irradiation coefficient Dp(x) (corrected irradiation amount) for correcting the adjacent effect. The unknown adjacent effect correction irradiation coefficient Dp(x) can be defined by the same threshold model for adjacent effect correction as the existing method, which uses the backscattering coefficient η, the irradiation threshold Dth of the threshold model, the pattern area density ρ, and the distribution function g(x).

[0086] Next, for each pixel 36, the dose mapping creation unit 52 calculates the incident exposure dose D(x) (dose) to be irradiated to the pixel 36. For example, the incident exposure dose D(x) can be calculated as a value obtained by multiplying a preset reference exposure dose Dbase by the proximity effect correction exposure coefficient Dp and the pattern area density ρ'. The reference exposure dose Dbase is defined as Dth / (1 / 2 + η), for example. According to the above, the originally desired incident exposure dose D(x) corrected for the proximity effect based on the layout of a plurality of graphic patterns defined in the drawing data can be obtained.

[0087] Then, the dose mapping creation unit 52 creates a dose map that defines the incident exposure dose D(x) for each pixel 36 in bar units. The incident exposure dose D(x) for each such pixel 36 is, by design, a predetermined incident exposure dose D(x) irradiated to the control grid 27 of the pixel 36. In other words, the dose mapping creation unit 52 creates a dose map that defines the incident exposure dose D(x) for each control grid 27 in bar units. The created dose map is stored in the storage device 142, for example.

[0088] As a defective beam detection process (S110), the detection unit 56 detects defective beams from the multi-beams 20. Examples of defective beams include dose-excessive defective beams with excessive doses irradiated due to inability to control the beam dose, and dose-insufficient defective beams with insufficient doses irradiated due to inability to control the beam dose. Among the dose-excessive defective beams, there are always-on on-defective beams and a part of the control-defective beams with poor irradiation time control. Among the dose-insufficient defective beams, there are always-off off-defective beams and the remaining part of the control-defective beams. Among the always-on on-defective beams, the beam that always irradiates the maximum irradiation time Ttr in one emission regardless of the control dose. Or, furthermore, irradiation continues even during movement between pixels. In addition, among the always-off off-defective beams, the beam is always turned off regardless of the control dose. Specifically, under the control of the drawing control unit 74, the drawing mechanism 150 controls each of the multi-beams 20 to be beam-on one by one through the individual blanking mechanism 47, and controls all the remaining beams to be beam-off. In this state, the beam for which no current is detected by the Faraday cup 106 is detected as an off-defective beam. Conversely, the control is switched from this state so that the beam to be detected becomes beam-off. At this time, the beam for which current is always detected by the Faraday cup 106 despite the change from beam-on to beam-off is detected as an on-defective beam. After switching from beam-on to beam-off, the beam for which current is detected by the Faraday cup 106 for a specified period is detected as a control-defective beam. If the presence or absence of defective beams and which position the defective beam is located at are confirmed for all the beams of the multi-beams 20 in the same way in sequence, it is possible to detect the presence or absence of defective beams.

[0089] In addition, the dose d' of the opening defect beam that is always on can be defined by the following formula (1) using the emission cycle Tsc (time) and the current density J. The emission cycle Tsc can be defined by the maximum irradiation time Ttr for each emission of the multi-beam 20. Alternatively, the maximum irradiation time Ttr for each emission may include the switching time taken for the switching process of switching from a certain pixel of the irradiation beam to the next pixel, the stabilization time of the beam deflection, and the data transfer time.

[0090]

Equation 1

[0091] (1) d' = j·Tsc

[0092] In addition, for the dose of the control defect beam that is only on during a specified period, the time during which the beam is on can be used instead of the emission cycle Tsc in formula (1).

[0093] As the modulation rate calculation step (S112), the modulation rate calculation unit 59 calculates, for each pixel 36, the dose modulation rate (first dose modulation rate) of the beam to the pixel 36 for correcting the position shift of the irradiation pattern caused by the position shift of the beam irradiated to the pixel 36 in the drawing order, and the dose modulation rate (second dose modulation rate) for dose distribution to at least one pixel around the pixel.

[0094] Figure 11 It is a diagram for explaining an example of the position shift correction method of Embodiment 1. In Figure 11 In the example of (a), it shows the case where the beam a' irradiated to the pixel at coordinates (x, y) is shifted in the -x, -y direction. In order to correct the position shift of the pattern formed by the beam a' with such a position shift to be consistent with the pixel at coordinates (x, y) as Figure 11 in (b), by allocating the irradiation amount of the offset amount to the pixels on the side opposite to the direction of the surrounding pixels with the offset, the correction can be performed. In Figure 11 In the example of (a), it is only necessary to allocate the irradiation amount shifted to the pixel at coordinates (x, y - 1) to the pixel at coordinates (x, y + 1). It is only necessary to allocate the irradiation amount shifted to the pixel at coordinates (x - 1, y) to the pixel at coordinates (x + 1, y). It is only necessary to allocate the irradiation amount shifted to the pixel at coordinates (x - 1, y - 1) to the pixel at coordinates (x + 1, y + 1).

[0095] In Embodiment 1, an amount of allocation (modulation rate of the second beam) that proportionally allocates the irradiation amount to at least one surrounding pixel according to the position offset amount of the beam is calculated. The modulation rate calculation unit 59 calculates the modulation rate of the beam to this pixel and the modulation rate of the beam to at least one surrounding pixel according to the ratio of the area shifted due to the position shift of the beam to this pixel. Specifically, for a surrounding pixel where a part of the beam overlaps when the beam shifts from the pixel of interest, the ratio obtained by dividing the area of the offset amount (the area of the overlapping beam part) by the beam area is calculated as the amount of allocation (modulation rate of the beam) to the pixel located on the side opposite to the overlapping pixel with respect to the pixel of interest.

[0096] In Figure 11 the example of (a), the area ratio of the shift to the pixel at coordinates (x, y - 1) can be calculated by (x-direction beam size - (-x)-direction offset amount) × y-direction offset amount / (x-direction beam size × y-direction beam size). Therefore, the amount of allocation (modulation rate of the beam) V for allocation to the pixel at coordinates (x, y + 1) for correction can be calculated by (x-direction beam size - (-x)-direction offset amount) × y-direction offset amount / (x-direction beam size × y-direction beam size).

[0097] In Figure 11 the example of (a), the area ratio of the shift to the pixel at coordinates (x - 1, y - 1) can be calculated by -x-direction offset amount × -y-direction offset amount / (x-direction beam size × y-direction beam size). Therefore, the amount of allocation (modulation rate of the beam) W for allocation to the pixel at coordinates (x + 1, y + 1) for correction can be calculated by -x-direction offset amount × -y-direction offset amount / (x-direction beam size × y-direction beam size).

[0098] In Figure 11 the example of (a), the area ratio of the shift to the pixel at coordinates (x - 1, y) can be calculated by -x-direction offset amount × (y-direction beam size - (-y)-direction offset amount) / (x-direction beam size × y-direction beam size). Therefore, the amount of allocation (modulation rate of the beam) Z for allocation to the pixel at coordinates (x + 1, y) for correction can be calculated by -x-direction offset amount × (y-direction beam size - (-y)-direction offset amount) / (x-direction beam size × y-direction beam size).

[0099] As a result, the modulation rate U of the beam for the pixel at coordinates (x, y) that is not allocated and remains can be obtained by calculating 1 - V - W - Z.

[0100] As described above, for each pixel, the modulation rate of the beam directed to the pixel and the modulation rate of the beam directed to at least one surrounding pixel as the allocation destination are calculated.

[0101] As the insufficient defect beam pixel determination step (S113), the determination unit 68 determines the pixels irradiated with the dose-insufficient defect beams among the defect beams.

[0102] As the dose calculation step (S114) for each path, the dose map creation unit 60 (dose calculation unit) reads the dose map from the storage device 142 and calculates the dose for each path of the multiple depictions for each pixel. In Figure 8 In the example, the amount of 32 beam pitches (= 4 times × 8 beam pitches) is moved in the x direction by 4 tracking operations. One drawing process is performed during the movement of this amount of 32 beam pitches. In such a configuration, when the multi-beam 20 is composed of, for example, 512 × 512 beams, by one continuous movement of the XY stage 105 for drawing each strip region 32 from one end to the other end, multiple depictions (multiplicity = 16) based on 16 times (= 512 / 32) of drawing processes (paths) are performed for each pixel. In this case, for each path, the arrangement positions of the beams irradiated to each pixel are different. Further, when the multi-beam 20 is composed of, for example, 32 × 32 beams, one drawing process (path) is performed for each pixel by one continuous movement of the XY stage 105 for drawing each strip region 32 from one end to the other end. Therefore, by, for example, 4 repeated continuous movements of the XY stage 105 with respect to each strip region 32, multiple depictions (multiplicity = 4) based on 4 times of drawing processes (paths) are performed for each pixel. In this case, as long as the irradiation positions of the respective beams are not intentionally shifted, the positions of the beams irradiated to each pixel are the same for each path. Which beam irradiates each pixel in each path is determined according to the drawing order. Further, in the first embodiment, instead of the number of movements of the stage, each drawing process of the multiple depictions is expressed as one path.

[0103] Figure 12 It is a diagram showing an example of the dose of each path of the multiple depictions using the beam without position shift in the first embodiment. When the beams used in each path do not include defect beams, for example, as shown in Figure 12 (a) of, the dose of each path of the multiple depictions of each pixel can be defined as the value obtained by dividing the total dose T(x) irradiated to each pixel by the multiplicity (number of paths). For example, when the beam used in one path is an open defect beam, the dose becomes Dpmax in the path using the open defect beam. For example, as shown in Figure 12As shown in (b) thereof, the dose of each remaining path can be defined as the value obtained by dividing the remaining dose obtained by subtracting the dose Dpmax based on the on-defect beam from the total dose T(x) irradiated to each pixel by the remaining number of multiple times (the remaining number of paths). Further, the dose mapping creation unit 60 adds the dose shortage amount in the pixel (position) irradiated by the dose shortage defect beam with a shortage of dose among the multi-beams 20 to the dose irradiated by a path different from the drawing process with a shortage of dose in the multiple drawing. For example, when the beam used in one path is an off-defect beam, the dose becomes zero in the path using the off-defect beam. Therefore, for example, as shown in (c) of Figure 12 the dose shortage amount is added to the dose of at least one of the remaining paths. If there is no position shift of each beam, such calculation can be performed. However, as described above, each beam of the multi-beam 20 has a position shift.

[0104] Therefore, the dose mapping creation unit 60 assigns the assigned dose obtained by multiplying the dose D of the pixel 36 by the calculated dose modulation rate (second dose modulation rate) to the surrounding pixels as the assignment destination for each path and for each pixel 36. Thereby, a dose corrected for the position shift / shape shift of the pattern caused by the position shift of the irradiation position of the beam can be obtained. Using the dose of each pixel 36 (control grid 27) after correcting the position shift of the irradiation position, a dose mapping (3) for each path is created.

[0105] As the dose excess defect beam pixel determination step (S116), the determination unit 68 determines the pixel irradiated by the dose excess defect beam.

[0106] As the determination step (S120), the determination unit 62 determines, for each pixel irradiated by the dose excess defect beam, whether the surrounding beam components of the dose excess defect beam can share the dose excess amount to cancel the excess dose caused by the dose excess defect beam. If sharing is possible, the process proceeds to the dose assignment step (S122). In the case where sharing is not possible, the process proceeds to the surrounding pixel determination step with a large dose (S130).

[0107] Figure 13 FIG. is an example showing the relationship between the control grid of Embodiment 1, the irradiation position of the beam, and the pattern edge. Each beam of the multi-beam 20 should ideally irradiate the corresponding control grid 27, but as shown in Figure 13As shown, the actual irradiation position 39 often deviates from the control grid 27. Then, when there are dose excess defect beams 10 among these beams, furthermore, the positional relationship between the object to be depicted and the pattern becomes a problem. As a hypothetical case, there is case A where the irradiation position of the dose excess defect beam 10 is outside the pattern, that is, outside the pattern, beyond the pattern edge 11a. There is also case B where the irradiation position of the dose excess defect beam 10 is on the pattern edge 11b. There is also case C where the irradiation position of the dose excess defect beam 10 is inside the pattern, that is, inside the pattern and near the pattern edge 11c. There is also case D where the irradiation position of the dose excess defect beam 10 is inside the pattern and at a position sufficiently far from the pattern edge 11d.

[0108] The determination unit 62 determines whether it is possible to have the peripheral beam components of the dose excess defect beam share the dose excess amount (reduce the shared dose) to offset the excess dose caused by the dose excess defect beam 10. The peripheral beam (group) may also include beams of other paths.

[0109] Since negative doses cannot be irradiated, in order to perform sharing, a positive finite value with a non-zero dose of the peripheral beam group is required. Therefore, in case A where it is outside the pattern, the peripheral beam is also outside the pattern, so the dose is originally zero and sharing cannot be performed. On the other hand, in the remaining cases B, C, and D, the peripheral beam can be inside the pattern, so in principle sharing can be performed. However, in cases B and C, depending on the position of the dose excess defect beam, the position after the offset of the peripheral beam, and the positional relationship with the pattern edge, it is sometimes difficult to have the peripheral beam components of the dose excess defect beam share the dose excess amount. Therefore, in addition to the case where the determination unit 62 determines to share the dose excess amount in case A, it can also be the case where the determination unit 62 determines to share the dose excess amount in cases A, B, and C. It is only necessary to preset which one to select.

[0110] As the dose allocation process (S122), the dose allocation processing unit 61 performs an allocation process to have the peripheral beam components of the dose excess defect beam share the dose excess amount to offset the excess dose caused by the dose excess defect beam. First, the excess dose can be obtained by subtracting the dose D that should be irradiated to the pixel 36 from the dose of the dose excess defect beam. The excess dose Δ can be defined by the following formula (2).

[0111]

Equation 2

[0112] (2) Δ = d' - D

[0113] Figure 14 is a diagram for explaining the beam distribution of Embodiment 1. In Figure 14In [the figure], the vertical axis represents the beam intensity, and the horizontal axis represents the position. Ideally, the intensity of each beam of the multi-beam is a rectangular distribution with a width obtained by multiplying the width of the shaping aperture by the reduction ratio. However, in reality, blurring occurs due to the aberration of the optical system, and for example, it becomes a distribution close to a Gaussian distribution. In this case, the width obtained by multiplying the width of the shaping aperture by the reduction ratio is defined as the beam size. Therefore, the actual beam has a weak blurring part around this beam size. The excess dose generated by this blurring part also has a great influence on the shape of the pattern edge. Therefore, in Embodiment 1, the distance L from the irradiation position (the center of gravity of the dose excess defect beam 10) of the dose excess defect beam 10, which is highly likely to be affected by the blurring part, to the pattern edge 11c within 3σ of the beam distribution is defined as the vicinity of the pattern edge 11c in Case C. In addition, in Case D where the irradiation position of the dose excess defect beam 10 is on the pattern center side where the distance L from the irradiation position (the center of gravity of the dose excess defect beam 10) of the dose excess defect beam 10 to the pattern edge 11c is greater than 3σ of the beam distribution, although it is affected by the excess dose, compared with Cases B and C, correction with reduced accuracy is sufficient. Therefore, in the cases of Cases B and C and in the case of Case D, it is preferable to distinguish the subsequent processing.

[0114] Figure 15 This is a diagram showing an example of a defect beam in the pattern center part of Embodiment 1 and its surrounding beams. In the case of Case D, for example, 11 (N = 11) beams up to the irradiation positions 39a to 39k within the beam-to-beam pitch are used as the surrounding beams. The beam-to-beam pitch used here can be the dimension in the design. In the case of Case D where the irradiation position of the dose excess defect beam 10 is on the pattern center side where the distance L from the irradiation position (the center of gravity of the dose excess defect beam 10) of the dose excess defect beam 10 to the pattern edge 11d is greater than 3σ of the beam distribution, the influence of the excess dose on the shape of the pattern edge is small. Therefore, it is not necessary to improve the accuracy so much, and in order to shorten the operation processing time, the center of gravity position of all the shared doses is not considered. In the case of Case D, the dose allocation processing unit 61 obtains each shared dose δd by dividing the excess dose Δ by the determined number N of the surrounding beams. Each shared dose δd can be defined by the following formula (3).

[0115]

Formula 3

[0116] (3) δd = Δ / N

[0117] In addition, in the case of Scenario D, in order to improve the calibration accuracy, the shared dose may also be changed according to the distance ri from the irradiation position of the overdose defect beam 10 to the irradiation positions of the peripheral beams. i represents the index of the peripheral beam that is the target among the N peripheral beam groups. In this case, each shared dose δdi can be defined, for example, by the following formula (4) using the overdose Δ and the distance ri.

[0118]

Equation 4

[0119]

[0120] Then, the dose allocation processing unit 61 subtracts the corresponding shared dose δdi from the dose D of each of these multiple peripheral beams.

[0121] On the other hand, in Case B where the irradiation position of the overdose defect beam 10 is on the pattern edge 11b and in Case C where the irradiation position of the overdose defect beam 10 is within the pattern and near the pattern edge 11c, according to the sharing method of the overdose, the pattern edge shape changes. Therefore, in order to improve the calibration accuracy, the centroid position of all the shared doses is considered.

[0122] Figure 16 It is a diagram showing an example of a defect beam and its peripheral beams on or near the pattern edge in Embodiment 1. The beam whose irradiation position 39 is within the pattern, for example, within a beam pitch of 2 from the irradiation position of the overdose defect beam 10, is used as the peripheral beam. The beam pitch used here can also be a design dimension. It is only necessary to appropriately set the range up to which the peripheral beam is defined.

[0123] Next, a plurality of peripheral beams around the overdose defect beam 10 are set as a plurality of groups each composed of a preset number of peripheral beams. For example, a plurality of groups each composed of every three adjacent peripheral beams are set. Then, in cases B and C, the dose allocation processing unit 61 calculates a plurality of allocated doses taking into account the centroid position. Specifically, it operates as follows. For each of the plurality of groups, the dose allocation processing unit 61 calculates each share dose according to the distance ri from the irradiation position of the overdose defect beam 10 to the irradiation positions of the three peripheral beams constituting the group. For example, for the three peripheral beams at the irradiation positions 39a, 39b, and 39c constituting the group G1, the share dose δd1 for the beam at the irradiation position 39a, the share dose δd2 for the beam at the irradiation position 39b, and the share dose δd3 for the beam at the irradiation position 39c can be obtained by the above formula (4) using the overdose Δ, the distance r1 from the irradiation position of the overdose defect beam 10 to the irradiation position 39a of the peripheral beam, the distance r2 from the irradiation position of the overdose defect beam 10 to the irradiation position 39b of the peripheral beam, and the distance r3 from the irradiation position of the overdose defect beam 10 to the irradiation position 39c of the peripheral beam. The same applies to other groups.

[0124] For each group, the dose allocation processing unit 61 calculates the centroid position of the plurality of share doses shared by the three peripheral beams constituting the group using the calculated share doses for each. The centroid position Gj' of the plurality of share doses for each group can be defined, for example, by the following formula (5) using the vector distance ri from the irradiation position of the overdose defect beam 10 to the irradiation positions of the three peripheral beams constituting the group Gj and the share dose δdi. j represents the index of the group to be targeted among the plurality of groups. In formula (5), the centroid position Gj' is represented by a vector, but of course, it can also be decomposed into the x-direction position dx and the y-direction position dy from the irradiation position of the overdose defect beam 10.

[0125]

Equation 5

[0126]

[0127] The dose distribution processing unit 61 selects a group Gj among the multiple groups, where the offset between the centroid position Gj' and the irradiation position of the dose-excess defective beam 10 is smaller. Then, the dose distribution processing unit 61 performs distribution processing so that the three peripheral beams of the selected group share the dose-excess amount. In addition, in cases where the number of paths is large, etc., the number of "multiple groups" increases. Therefore, it is preferable not to perform calculations for all groups, but to perform calculations starting from the priority groups (the priority is determined based on the distance from the defective beam, etc.), and end the calculations at the time when the centroid with the required accuracy is obtained (the remaining groups are not calculated). Specifically, the dose distribution processing unit 61 reduces the corresponding shared dose δdi from the dose D of each of the three selected peripheral beams.

[0128] In contrast, in case A where the dose-excess defective beam 10 is outside the pattern, the peripheral beams are also outside the pattern, so the dose is originally zero and sharing cannot be performed. In this case, an error will occur in the shape of the pattern to be drawn. Therefore, in Embodiment 1, the centroid position of the dose-excess amount is moved within the pattern. Hereinafter, a specific description will be given.

[0129] As the step (S130) of determining the peripheral pixels with a large dose, the peripheral pixel determination unit 64 with a large dose determines, among the multiple peripheral pixels of the dose-excess defective beam 10, the peripheral pixels (irradiation positions) within the pattern that have a larger dose compared to other peripheral pixels (irradiation positions).

[0130] Figure 17 is a diagram showing an example of the relationship between the dose curve and the pixels in Embodiment 1. If there is no dose-excess defective beam, as shown in Figure 17 (a) of, there is no offset at the edge position of the pattern. However, as shown in Figure 17 (b) of, if the excess dose generated by the dose-excess defective beam 10 is irradiated to a position outside the pattern, the position of the pattern edge shifts. In Figure 17 (c) of, the pixels 2 irradiated with the excess dose (here, the maximum dose Dpmax) generated by the on-defective beam are shown as viewed from the upper surface. In the example of Figure 17 (b) of, a relatively large dose is irradiated to pixels 13 and 15, for example, one pixel inside the pixel that overlaps with the edge position of the pattern. In this case, the peripheral pixel determination unit 64 with a large dose determines such pixels 13 and 15 as the peripheral pixels within the pattern that have a larger dose compared to other peripheral pixels (irradiation positions). In addition, when determining the peripheral pixels, it is first required that the position is close to the dose-excess defective beam. When selecting the beam with a large dose from the group of close beams, the efficiency is good.

[0131] As the additional dose distribution step (S132), the distribution unit 65 (additional dose distribution unit) irradiates the dose excess defective beam 10, which has an excessive dose that cannot be controlled in terms of the dose of the beam among the multiple beams 20, to a position with a dose deficiency for offsetting the excessive dose within the range where the excessive dose spreads. Thereby, the additional dose for making the dose distribution (first dose distribution) based on the excessive dose generated in the specimen 101 into a combined dose distribution (second dose distribution) whose center (e.g., the center of gravity position) is within the range of the dose distribution based on the excessive dose and inside the pattern of the depiction object where there is beam irradiation for offsetting the excessive dose is distributed to the position within the pattern. As the position with a dose deficiency for offsetting the excessive dose within the range where the excessive dose spreads, for example, the vicinity of the pattern end of the depiction object can be cited. For example, a position within the range of 2 to 3 beam sizes from the pattern end can be cited. For example, in case A, the additional dose that moves the center of the dose distribution generated in the specimen 101 (substrate) by irradiating outside the pattern into the pattern is distributed to the position within the pattern. For example, in cases B and C, the additional dose that moves the center of the dose distribution generated in the specimen 101 (substrate) by irradiating on or near the pattern edge 11 into the inside of the pattern is distributed to the position within the pattern. The distribution unit 65 distributes the additional dose so that the peripheral pixel (irradiation position) with a higher dose among the multiple peripheral pixels of the dose excess defective beam 10 compared to other peripheral pixels (irradiation positions) within the pattern becomes the center (e.g., the center of gravity position) of the new dose distribution (the combined dose distribution described later). At this time, the distribution unit 65 distributes the additional dose in a manner not exceeding a preset dose threshold. As the dose threshold, for example, a value of about 1 / 2 of the maximum dose Dpmax is preferably set. Specifically, it operates as follows.

[0132] Figure 18 FIG. is an example showing the distribution of the additional dose and the center of gravity position in Embodiment 1. Figure 19 FIG. is an example showing the dose distribution based on the excessive dose, the dose distribution based on the additional dose, and the combined dose distribution of both in Embodiment 1. In Figure 18 (a) of, an excessive dose (here, the maximum dose Dpmax) is irradiated to the pixel 2 outside the pattern. In this case, the center of gravity position of the excessive dose is within the pixel 2. Therefore, as shown in Figure 18 (b) of, the additional dose is distributed to the peripheral pixel 12 within the pattern that is, for example, 4 pixels deviated in the -x direction from the pixel 2 outside the pattern. For example, the same maximum dose Dpmax as that of the pixel 2 is distributed.

[0133] Alternatively, in the case where the maximum dose Dpmax exceeds a preset maximum dose when the maximum dose is allocated, as an additional dose, for example, Dpmax / 2 which is 1 / 2 of the maximum dose is allocated to the peripheral pixel 12. Then, the additional dose allocated to the peripheral pixel 12 is reduced, and accordingly, additional doses are also allocated to other peripheral pixels. In Figure 18 In the example of (b), in addition to the peripheral pixel 12, an additional dose is allocated to the peripheral pixel 14 within the pattern that is, for example, 4 pixels deviated in the -x direction and 2 pixels deviated in the y direction from the pixel 2 outside the pattern. As the additional dose, the remaining Dpmax / 2 which is, for example, 1 / 2 of the maximum dose that has not been fully allocated to the peripheral pixel 12 is allocated. With these additional doses, the center of gravity position of the excess dose located at the pixel 2 can be made to move to the peripheral pixel 13 which is the intermediate position between the pixel 2 and the pixel 12 and the peripheral pixel 15 which is the intermediate position between the pixel 2 and the pixel 14 as shown in Figure 18 (c). In other words, for the dose distribution based on the excess dose shown in Figure 19 , an additional dose is allocated to the peripheral pixels 12(14) within the range of the dose distribution based on the excess dose, thereby generating a dose distribution based on the additional dose. Thereby, the dose distribution that affects the pattern formed on the specimen 101 can be converted from the dose distribution based on the excess dose to the synthesized dose distribution shown in Figure 19 which is the synthesis of the dose distribution based on the excess dose and the dose distribution based on the additional dose. Similarly, in the case where the center of the dose distribution that affects the pattern formed on the specimen 101 is moved from outside the pattern to inside the pattern. Here, an additional dose is allocated to the peripheral pixels 12(14) so that the center (for example, the center of gravity position) of the synthesized dose distribution is located inside the pattern. In Figure 18 (c), the center of the synthesized dose distribution is represented by the peripheral pixels 13(15). Thereby, the excess dose irradiated to the pixel 2 outside the pattern can be eliminated. On the other hand, in this case, excess doses are irradiated to the peripheral pixels 13 and 15. Therefore, subsequently, the excess doses generated in the peripheral pixels 13 and 15 are eliminated.

[0134] As the dose elimination calculation process (S134), the dose elimination calculation unit 66 calculates the dose increase amount generated at the center (for example, the center of gravity position) of the dose distribution that has moved due to the allocation of the additional dose. As shown in Figure 18 (c), at the peripheral pixels 13 and 15 that become the center of gravity positions that have moved due to the allocation of the additional dose, a dose increase amount of Dpmax appears respectively on the appearance.

[0135] As the correction process (S136), the correction unit 67 performs correction to reduce the dose increase amount generated at the center of the combined dose distribution (e.g., the center of gravity position) due to the allocated additional dose from the dose irradiated to the center of the combined dose distribution or the vicinity of the center of the combined dose distribution. As the vicinity of the center of the combined dose distribution, for example, a range of 2 to 3 beam sizes from the center of the combined dose distribution is preferably used. For example, correction is performed to reduce the dose irradiated to the center (e.g., the center of gravity position) of the dose distribution that moves along a path different from the path of the allocated additional dose in multiple scans. Sometimes, the center position of the moved dose distribution is offset from the position of the irradiated beam. Alternatively, the dose of the irradiation positions of multiple beams can also be corrected with respect to the center position of one dose distribution. In these cases, correction is performed to reduce the dose irradiated to the vicinity of the center of the dose distribution. In Figure 18 In the example of (c), the dose increase amount Dpmax generated at the peripheral pixel 13 is reduced from the dose of other paths. When the dose increase amount Dpmax cannot be completely reduced by one path, multiple paths are used to reduce the dose increase amount Dpmax. Similarly, the dose increase amount Dpmax generated at the peripheral pixel 15 is reduced from the dose of other paths. When the dose increase amount Dpmax cannot be completely reduced by one path, multiple paths are used to reduce the dose increase amount Dpmax. In Embodiment 1, as the center of gravity position after movement, the peripheral pixels 13 and 15 that originally had a larger dose than other peripheral pixels (irradiation positions) are deliberately selected. Therefore, the risk of the dose increase amount Dpmax remaining without being completely reduced can be reduced. In addition, if the reduction is performed through the same path, the dose increase amount Dpmax can also be reduced from the dose of the same path.

[0136] As the determination process (S138), the determination unit 63 determines whether all the excess doses of all the dose excess defective beams have been completely canceled. If there are still dose excess defective beams whose excess doses have not been completely canceled, the process returns to the determination process (S120), and the same respective processes are repeated until the cancellation of the excess doses of all the dose excess defective beams is completed.

[0137] In the above example, the maximum dose Dpmax during the irradiation time is used as the dose irradiated by the dose excess defective beam, but it is not limited thereto. As the dose irradiated by the dose excess defective beam, it is preferable to use a value obtained by further adding the dose for the stabilization time for beam deflection to the maximum dose Dpmax during the irradiation time. Or, further, it is preferable to include the dose for such a switching time and data transfer time in the switching process of switching from a certain pixel irradiated by the beam to the next pixel.

[0138] As the irradiation time calculation process (S140), the irradiation time calculation unit 72 corrects the position deviation of the beam, and calculates the irradiation time t corresponding to the dose of each pixel of each path where the under-dose of the under-dose defect beam and the over-dose of the over-dose defect beam are canceled out. The irradiation time t can be calculated by dividing the dose D by the current density. The irradiation time t for each pixel 36 (control grid 27) is calculated as a value within the maximum irradiation time Ttr that can be irradiated by one emission of the multi-beam 20. The irradiation time data is stored in the storage device 142.

[0139] As the drawing process (S142), first, the drawing control unit 74 sorts the irradiation time data in the emission order according to the drawing order. Then, the irradiation time data is transmitted to the deflection control circuit 130 in the emission order. The deflection control circuit 130 outputs a blanking control signal to the blanking aperture array mechanism 204 in the emission order, and outputs a deflection control signal to the DAC amplification units 132 and 134 in the emission order. Then, the drawing mechanism 150 uses the multi-beam 20 including the over-dose defect beam to perform multiple drawing, thereby drawing a pattern on the specimen 101.

[0140] As described above, according to the first embodiment, in multi-beam drawing, the shape error of the pattern caused by the over-dose and / or under-dose can be reduced by a simple method. Further, in multi-beam drawing, when the over-dose defect beam is irradiated to a position outside the end of the pattern, the shape error of the pattern caused by the defect beam can be reduced by a simple method. Therefore, the calculation processing time of the dose modulation for correcting the shape error of the pattern caused by the over-dose can be shortened. As a result, the calculation processing of the dose modulation and the drawing operation can be executed in parallel.

[0141] As described above, the embodiments have been described with reference to specific examples. However, the present invention is not limited to these specific examples. In the above example, the case where the irradiation time of each beam of the multi-beam 20 is individually controlled within the maximum irradiation time Ttr of one emission has been described. However, it is not limited thereto. For example, the maximum irradiation time Ttr of one emission is divided into a plurality of sub-emissions with different irradiation times. Then, for each beam, a combination of sub-emissions is selected from the plurality of sub-emissions so as to be the irradiation time of one emission. Then, it is preferable to continuously irradiate the same pixel with the selected combination of sub-emissions with the same beam, and control the irradiation time of one emission for each beam.

[0142] In addition, in the above example, a case where a 10-bit control signal is input to control each control circuit 41 is shown, but the number of bits can be appropriately set. For example, a 2-bit or a 3-bit to 9-bit control signal can also be used. Additionally, a control signal of 11 bits or more can be used.

[0143] Furthermore, parts that are not directly required in the description of the present invention, such as the device configuration, control method, etc., are omitted from the description, but the required device configuration and control method can be appropriately selected and used. For example, the description of the control unit configuration for controlling the drawing device 100 is omitted, but of course, the required control unit configuration can also be appropriately selected and used.

[0144] In addition, all multi-charged particle beam drawing devices and multi-charged particle beam drawing methods that have the elements of the present invention and can be appropriately designed and changed by those skilled in the art are included in the scope of the present invention.

[0145] Industrial Applicability

[0146] Relates to a multi-charged particle beam drawing device and a multi-charged particle beam drawing method, and can be used, for example, in a method for reducing the size deviation of a pattern caused by multi-beam drawing.

[0147] Explanation of Symbols

[0148] 2, 12, 13, 14, 15 pixels

[0149] 10 dose-excessive defect beams

[0150] 11 pattern edges

[0151] 20 multi-beams

[0152] 22 holes

[0153] 24 control electrodes

[0154] 25 through holes

[0155] 26 counter electrodes

[0156] 27 control grids

[0157] 28 pixels

[0158] 29 sub-irradiation regions

[0159] 30 drawing regions

[0160] 32 bar regions

[0161] 31 substrates

[0162] 33 support tables

[0163] 34 Irradiation area

[0164] 35 Unit area

[0165] 36 Pixel

[0166] 37, 39 Irradiation position

[0167] 41 Control circuit

[0168] 47 Separate blanking mechanism

[0169] 50 Rasterization unit

[0170] 52 Dose mapping creation unit

[0171] 54 Beam position offset mapping creation unit

[0172] 56 Detection unit

[0173] 59 Modulation rate calculation unit

[0174] 60 Dose mapping creation unit

[0175] 61 Dose allocation processing unit

[0176] 62 Judgment unit

[0177] 63 Judgment unit

[0178] 64 Surrounding pixel determination unit with large dose

[0179] 65 Allocation unit

[0180] 66 Elimination dose calculation unit

[0181] 67 Correction unit

[0182] 68 Determination unit

[0183] 72 Irradiation time calculation unit

[0184] 74 Drawing control unit

[0185] 100 Drawing device

[0186] 101 Specimen

[0187] 102 Electron gun barrel

[0188] 103 Drawing chamber

[0189] 105 XY stage

[0190] 110 Control computer

[0191] 112 Memory

[0192] 130 Deflection control circuit

[0193] 132, 134 DAC Amplification Unit

[0194] 139 Workbench Position Detector

[0195] 140, 142, 144 Storage Devices

[0196] 150 Drawing Mechanism

[0197] 160 Control System Circuit

[0198] 200 Electron Beam

[0199] 201 Electron Gun

[0200] 202 Illumination Lens

[0201] 203 Shaping Aperture Array Substrate

[0202] 204 Blanking Aperture Array Mechanism

[0203] 205 Reduction Lens

[0204] 206 Limiting Aperture Substrate

[0205] 207 Objective Lens

[0206] 208, 209 Deflectors

[0207] 210 Mirror

[0208] 330 Diaphragm Area

[0209] 332 Peripheral Area

Claims

1. A multi-charged particle beam drawing device, characterized in that, Comprising: A beam forming mechanism that forms a multi-charged particle beam; A dose calculation circuit that calculates the dose at each position on the specimen; An additional dose distribution circuit that irradiates a dose excess defect beam, which is a dose excess in the multi-charged particle beam that cannot be dose-controlled by the beam, to a position with a dose deficiency for offsetting the excess dose within the range where the excess dose spreads. Thus, an additional dose for making a first dose distribution based on the excess dose generated in the specimen become a second dose distribution whose center is located within the range of the first dose distribution and inside the pattern of the drawing object where there is a beam irradiation for offsetting the excess dose, is distributed to the positions within the pattern; A correction circuit that performs correction to reduce the dose increase amount generated at the center of the second dose distribution due to the distribution of the additional dose from the dose irradiated to the center of the second dose distribution or near the center of the second dose distribution; and A drawing mechanism that uses the multi-charged particle beam including the dose excess defect beam to draw a pattern on the specimen.

2. The multi-charged particle beam drawing device according to claim 1, characterized in that The drawing mechanism performs multiple drawing, The dose calculation circuit adds the dose deficiency amount at the position irradiated by the dose deficiency defect beam in the multi-charged particle beam to the dose irradiated by a drawing process different from the drawing process with dose deficiency in the multiple drawing.

3. The multi-charged particle beam drawing device according to claim 1, characterized in that The additional dose distribution circuit distributes the additional dose in a manner not exceeding a preset dose threshold.

4. The multi-charged particle beam drawing device according to claim 1, characterized in that The additional dose distribution circuit distributes the additional dose in such a way that the irradiation position with a larger dose compared to the surrounding irradiation positions becomes the center of the second dose distribution.

5. The multi-charged particle beam drawing device according to claim 1, characterized in that As the dose irradiated by the dose excess defect beam, a value obtained by further adding the stable time for beam deflection to the dose during the irradiation time is used.

6. A multi-charged particle beam drawing method, characterized in that A multi-charged particle beam is formed, The dose at each position on the specimen is calculated, A dose excess defect beam, which is a dose excess in the multi-charged particle beam that cannot be dose-controlled by the beam, is irradiated to a position with a dose deficiency for offsetting the excess dose within the range where the excess dose spreads. Thus, an additional dose for making a first dose distribution based on the excess dose generated in the specimen become a second dose distribution whose center is located within the range of the first dose distribution and inside the pattern of the drawing object where there is a beam irradiation for offsetting the excess dose, is distributed to the positions within the pattern, Correction is performed to reduce the dose increase amount generated at the center of the second dose distribution due to the distribution of the additional dose from the dose irradiated to the center of the second dose distribution or near the center of the second dose distribution. Using the above-described multi-charged particle beam including the above-described over-dose defective beam, a pattern is drawn on a specimen.

7. The multi-charged particle beam drawing method according to claim 6, wherein the above-described drawing is performed as multiple drawing, and an under-dose amount at a position irradiated with an under-dose defective beam having an under-dose in the above-described multi-charged particle beam is added to a dose irradiated by a drawing process different from the under-dose drawing process in the above-described multiple drawing.

8. The multi-charged particle beam drawing method according to claim 6, wherein the above-described additional dose is allocated in a manner not exceeding a preset dose threshold.

9. The multi-charged particle beam drawing method according to claim 6, wherein the above-described additional dose is allocated in such a manner that an irradiation position having a larger dose than surrounding irradiation positions becomes the center of the second dose distribution.

10. The multi-charged particle beam drawing method according to claim 6, wherein as a dose irradiated by the above-described over-dose defective beam, a value obtained by further adding a dose for a stabilization time for beam deflection to a dose during an irradiation time is used.

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