Charged particle beam device

Abstract

Charged particle beam device with a charged particle beam source (101) designed to irradiate a sample (106) with a plurality of primary beams (104; 104a-c), a plurality of detectors (108) designed to detect secondary beams (107a-c) emitted by the sample in conjunction with the primary beams, a beam separator (105) configured to deflect the secondary beams in a direction different from that of the primary beams, and a deflector (110) provided between the beam separator and the detector for correcting a positional shift between the secondary beams generated in the beam separator together with a distortion of the beam shapes of the secondary beams generated in the beam separator, wherein the beam separator forms a first electric field (E) and a first magnetic field (B) which are perpendicular to each other in a plane perpendicular to the primary beams and causes the primary beams to move straight to deflect the secondary beams, wherein the deflector forms a second electric field (E2) and a second magnetic field (B2) which are perpendicular to each other, and wherein the strength of the second electric field and the strength of the second magnetic field are adjusted based on observation images that are different for each position irradiated with the primary beams.

Description

Technical area

[0001] The present invention relates to a charged particle beam device and, more particularly, to a technique for improving throughput using multiple charged particle beams. Background of the invention

[0002] A charged particle beam device is a device that detects secondary charged particles, such as secondary electrons or reflected electrons, emitted from a sample by irradiating the sample with a charged particle beam such as an electron beam or an ion beam, and generates an image for observing a fine structure of the sample. The charged particle beam device is used in a manufacturing process of a semiconductor or the like. In the manufacturing process of a semiconductor, an improvement in throughput is required, and a multiple charged particle beam device in which the sample is irradiated with multiple charged particle beams and the secondary charged particles emitted from the sample are detected by multiple detectors can be used.

[0003] To separate a primary beam, which is a charged particle beam irradiating the sample, and a secondary beam, which is the secondary charged particles emitted by the sample, the multiple charged particle beam device is equipped with a beam separator that deflects the secondary beam in a different direction than the primary beam. However, chromatic deflection aberration occurs in the secondary beam in the beam separator.

[0004] PTL 1 discloses that a multi-beam electron beam device is provided with an electrostatic deflector that corrects the chromatic deflection aberration caused by an electromagnetic deflector that is a beam separator for the beam. Citation listPatent literature

[0005] PTL 1: WO 2006 / 101116 A1

[0006] An electron detection system with a deflector for simultaneously and uniformly shifting all secondary beams relative to a scintillator plate is disclosed in US 2015 / 0 083 911 A1. Another electron beam device related to the invention is disclosed in US 2010 / 0 320 382 A1. Overview of the inventionTechnical problem

[0007] However, PTL 1 does not consider the positional shift between the secondary beams generated in the beam separator. Regarding the secondary beam, the length of a portion affected by an electric or magnetic field formed by the beam separator varies depending on the positions where the secondary beam impacts the beam separator. The longer the affected portion in the electric or magnetic field, the greater the amount of deflection. That is, the positional shift occurs between the secondary beams due to a difference in the positions where the secondary beam impacts the beam separator. If the positional shift is too large, the positional shift will interfere with the detection of the secondary beam.

[0008] Therefore, an object of the invention is to provide a charged particle beam device capable of reducing a positional shift between secondary beams generated in a beam separator. Solution to the problem

[0009] To achieve the above-described object, the invention proposes the charged particle beam devices defined in independent claims 1 to 3. A further advantageous feature is set out in dependent claim 4. Beneficial effect

[0010] According to the invention, it is possible to provide the charged particle beam device capable of reducing the positional shift between the secondary beams generated in the beam separator. Brief description of the drawings [ Fig. 1] Fig. 1 is a schematic diagram showing an example of a charged particle beam device according to a first embodiment. [ Fig. 2] Fig. 2 is a diagram illustrating a beam separator 105 using ExB. [ Fig. 3] Fig. 3 is a diagram illustrating secondary beams 107 in an electric field E or a magnetic field B formed by the beam separator 105. [ Fig. 4] Fig. 4 is a diagram showing an example of a position shift between the secondary beams 107 in a plane 302. [ Fig. 5] Fig. 5 is a diagram illustrating a correction of the position shift between the secondary beams 107 by a deflector 110. [ Fig. 6] Fig. 6 is a diagram illustrating a deflection angle of the secondary beams 107 in the beam separator 105 and the deflector 110. [ Fig. 7] Fig. 7 is a diagram illustrating correction of the beam shapes of the secondary beams 107 by the deflector 110. [ Fig. 8] Fig. 8 is a diagram showing an example of a processing flow for adjusting a ratio of the electric field to the magnetic field of the deflector 110 using the ExB. [ Fig. 9] Fig. 9 is a diagram showing an example of an adjustment sample 901 used for adjusting the ratio of the electric field to the magnetic field of the deflector 110 using the ExB. [ Fig. 10] Fig. 10 is a diagram showing an example of an adjusting screen 1001 used for adjusting the ratio of the electric field to the magnetic field of the deflector 110 using the ExB. [ Fig. 11] Fig. 11 is a schematic diagram showing a modification of the charged particle beam device according to the first embodiment. [ Fig. 12] Fig. 12 is a schematic diagram showing an example of a charged particle beam device according to a second embodiment. [ Fig. 13] Fig. 13 is a schematic diagram showing an example of a charged particle beam device according to a third embodiment. [ Fig. 14] Fig. 14 is a schematic diagram showing an example of the deflector 110 according to the third embodiment. Description of embodiments

[0011] Embodiments of a charged particle beam device according to the invention will be described below with reference to the accompanying drawings. The charged particle beam device is a device that allows observation of a sample by irradiating the sample with a charged particle beam represented by an electron beam, and may include various devices such as a scanning electron microscope or a scanning transmission electron microscope. As an example of the charged particle beam device, a multi-beam scanning electron microscope that allows observation of the sample using multiple electron beams will be described below. [First embodiment]

[0012] An overall configuration of the scanning electron microscope according to the present embodiment will be described with reference to Fig. 1. The scanning electron microscope includes an electron source 101, a multi-beam forming unit 103, a beam separator 105, a detector 108, a deflector 110, and a control unit 120.

[0013] The electron source 101 is a device that generates an electron beam 102 by emitting and accelerating electrons. The electron beam 102 generated by the electron source 101 is split into several primary beams 104 by the multi-beam forming unit 103. Fig. 1 shows, as an example, primary beams 104a, 104b, and 104c obtained by splitting the electron beam 102 into three. The primary beams 104a, 104b, and 104c impinge on the beam separator 105 and travel to a sample 106, and the sample 106 is irradiated with the primary beams 104a, 104b, and 104c. The primary beams 104a, 104b, and 104c irradiating the sample 106 are focused and deflected by a focusing lens, an objective lens, and a scanning deflector (not shown).

[0014] From the sample 106 irradiated with the primary beams 104a, 104b, and 104c, secondary electrons, reflected electrons, and the like are emitted as secondary beams 107a, 107b, and 107c. The secondary beams 107a, 107b, and 107c are emitted in conjunction with the primary beams 104a, 104b, and 104c, respectively, and strike the beam separator 105 and are deflected.

[0015] An example of the beam separator 105 will be described with reference to Fig. 2 described. Fig. Figure 2 is a view of the beam separator 105 as seen from the side of the electron source 101. (a) of Fig. 2 shows the effect on the primary beam 104, and (b) of Fig. 2 shows the effect on the secondary beam 107. The beam separator 105 has a positive electrode 105a, a negative electrode 105b, a positive magnetic pole 105c, and a negative magnetic pole 105d, and forms an electric field E from the positive electrode 105a to the negative electrode 105b and a magnetic field B from the positive magnetic pole 105c to the negative magnetic pole 105d. This means that the electric field E and the magnetic field B, which are perpendicular to each other, are formed in a plane perpendicular to the primary beam 104. The electric field E and the magnetic field B are called ExB because the electric field E and the magnetic field B are perpendicular to each other. When the electric field E and the magnetic field B are perpendicular to each other, the number of electrodes and magnetic poles is not limited to two, but can be eight or twelve.

[0016] As in (a) of Fig. 2, a force 201 generated by the electric field E and a force 202 generated by the magnetic field B act in opposite directions on the primary beams 104, and when the magnitude of the force 201 is equal to the magnitude of the force 202, the primary beams 104 move straight. On the other hand, as shown in (b) of Fig. As shown in Figure 2, since the force 201 generated by the electric field E and the force 202 generated by the magnetic field B act on the secondary beams 107 in the same direction, the secondary beams 107 are deflected in a direction different from that of the primary beams 104 due to a combined force of the force 201 and the force 202. That is, the primary beams 104 and the secondary beams 107 are separated by the action of the electric field E and the magnetic field B formed by the beam separator 105.

[0017] Returning to the presentation in Fig. 1, the secondary beams 107a, 107b, and 107c, which are deflected in a direction different from the primary beams 104a, 104b, and 104c, strike the detector 108 via the deflector 110, which will be described later. The detector 108 is a device having multiple detection units that detect each of the secondary beams 107a, 107b, and 107c. A detection signal from the detector 108 is sent to the control unit 120 and is used to generate an observation image of the sample 106.

[0018] The control unit 120 is a device that controls each part of the scanning electron microscope and is, for example, a general-purpose computer. The computer includes a processor such as a central processing unit (CPU), a storage device such as a memory and a hard disk drive (HDD), an input device such as a keyboard and a mouse, and a display device such as a liquid crystal display. The control unit 120 performs various types of processing by loading a program stored on the HDD into the memory and causing the CPU to execute the program. Part of the control unit 120 can be implemented by hardware such as a dedicated circuit. The control unit 120 generates and displays the observation image based on the detection signal sent from the detector 108.

[0019] To generate a suitable observation image, it is desirable that the secondary beams 107 emitted by the sample 106 be fully detected by the detector 108. However, the positional shift between the secondary beams 107 generated in the beam separator 105 may interfere with the detection of the secondary beams 107 performed by the detector 108. The positional shift between the secondary beams 107 is described below.

[0020] The secondary beams 107 in the electric field E or the magnetic field B formed by the beam separator 105 are described with reference to Fig. 3. Since the electric field E or the magnetic field B formed by the beam separator 105 has a spread in a moving direction of the secondary beams 107, the length of the portion affected by the electric field E or the magnetic field B of the secondary beams 107 differs depending on the positions of the secondary beams 107 impinging on the beam separator 105. For example, an affected portion 301a of the outer secondary beam 107a among the deflected secondary beams 107 is longer than an affected portion 301c of the inner secondary beam 107c. As a result, the outer secondary beam 107a is deflected more than the inner secondary beam 107c.

[0021] The position shift between the secondary beams 107 on the plane 302 in Fig. 3 is made with reference to Fig. 4. To simplify the description, a sample image plane is chosen as plane 302 which is substantially perpendicular to the deflected secondary rays 107 and in which the secondary rays 107 are most strongly focused. Fig. 4 shows nine secondary beams 107 as an example. Since the extent to which the secondary beams 107 are deflected differs depending on the length of the affected section 301 of the electric field E or the magnetic field B, the positional shift due to the difference in the incident position on the beam separator 105 occurs between the secondary beams 107 reaching the plane 302. That is, the outer secondary beam 107a is deflected more than the inner secondary beam 107c, so the beam spacing is widened. If the positional shift between the secondary beams 107 is too large, the secondary beams 107 that cannot be incident on the detector 108 are generated, which impairs the detection of the secondary beams 107.

[0022] The secondary beams 107 exhibit energy dispersion, and the extent of deflection varies depending on the energy. Therefore, the beam shapes are distorted. That is, the secondary beams 107 with high energy are deflected less by the electric field E or the magnetic field B than the secondary beams 107 with low energy, and therefore the beam shapes of the secondary beams 107, as shown in Fig. 4, distorted. The distortion of the beam shapes reduces the detection resolution of the secondary beams 107.

[0023] Therefore, in the present embodiment, the deflector 110 provided between the beam separator 105 and the detector 108 corrects the positional shift between the secondary beams 107 generated in the beam separator 105. The deflector 110 is a device that deflects the secondary beams 107 in the direction opposite to the beam separator 105 and is, for example, an electric field sector including a positive electrode and a negative electrode, or a magnetic field sector including a positive magnetic pole and a negative magnetic pole. In order to deflect the secondary beams 107 by the deflector 110 as shown in Fig. To deflect the beam as shown in Figure 1, an electric field sector with the positive electrode on the right and the negative electrode on the left is used, or a magnetic field sector with the positive magnetic pole at the front and the negative magnetic pole at the rear is used. The ExB, which forms an electric field and a magnetic field perpendicular to each other, can be used for the deflector 110.

[0024] The correction of the position shift between the secondary beams 107 by the deflector is described with reference to Fig. 5. (a) of Fig. 5 shows the effect of deflection by the deflector 110, and (b) of Fig. Figure 5 shows the arrangement of the secondary beams 107 corrected by the deflector 110 when the secondary beams 107 strike the detector 108. The deflector 110 deflects the secondary beams 107 in the direction opposite to that of the beam separator 105, so that positional shifts in the secondary beams 107 occur in a direction opposite to that in Fig. 4. As a result, the position shift generated by the beam separator 105 and the position shift generated by the deflector 110 cancel each other out, and as shown in (b) of Fig. As shown in Figure 5, the secondary beams 107 can impinge on the detector 108 with the reduced positional shifts. Regarding the distortion of the beam shapes due to the energy dispersion of the secondary beams 107, the beam shapes are improved because the effect of the beam separator 105 and the effect of the deflector 110 cancel each other out.

[0025] The deflection angle of the secondary beams 107 in the beam separator 105 and in the deflector 110 is determined with reference to Fig. 6. When the angle at which the secondary beam 107b located at the center of the plurality of secondary beams 107 is deflected by the beam separator 105 is θ1, and the angle at which the secondary beam 107b is deflected by the deflector 110 is θ2, θ1 and θ2 are opposite in direction. The angle of incidence of the secondary beam 107b on the detector 108 is preferably a right angle. Therefore, when the inclination angle of the detector 108 with respect to the beam separator 105 is θ, it is preferable that the deflection angle θ2 obtained by the deflector 110 satisfies the following equation. θ2=θ−θ1

[0026] The correction of the beam shapes of the secondary beams 107 by the deflector is described with reference to Fig. 7 described. Fig. Figure 7 shows the trajectories of secondary beams 107b-L, 107b-M, and 107b-H, which are the secondary beams 107b with different energies. Secondary beam 107b-L has low energy, secondary beam 107b-M has medium energy, and secondary beam 107b-H has high energy.

[0027] The deflection angle at the deflector 110 varies depending on the energy of the secondary beam 107b and becomes smaller the higher the energy. Therefore, the deflector 110 deflects the secondary beams 107 in the direction opposite to that of the beam separator 105 to reduce the distortion of the beam shapes. In particular, the distortion of the beam shapes disappears at an intersection point 701 of the secondary beams 107b-L, 107b-M, and 107b-H.

[0028] When the deflector 110 is an electric field sector or a magnetic field sector, the strength of the electric field or the magnetic field of the deflector 110 is determined according to the deflection angle θ2, and thus the position of the intersection point 701, which is the point where the distortion of the beam shapes disappears, is also uniquely determined. Since the highest detection resolution is achieved by detecting the secondary beams 107 where the distortion of the beam shapes has disappeared, it is particularly preferable that the detector 108 be provided at the position of the intersection point 701. However, if the detection resolution is equal to or higher than a predetermined value, the detector 108 may be provided at a position where the size of the beam shapes of the detected secondary beams 107 is equal to or smaller than a predetermined value, that is, near the intersection point 701.

[0029] When the deflector 110 uses the ExB, the deflection angle θ2 obtained by the deflector 110 can be expressed by the following equation, using the deflection angle θ2(E2) generated by the electric field E2 of the ExB and the deflection angle θ2(B2) generated by the magnetic field B2 of the ExB. θ2=θ2(E2)+θ2(B2)

[0030] While a combination of the electric field E2 and the magnetic field B2 at which θ2 becomes a predetermined value is continuously present, the position of the intersection point 701 also moves when a ratio of the electric field E2 to the magnetic field B2 changes. That is, by adjusting the ratio of the electric field E2 to the magnetic field B2, the position of the intersection point 701 can be moved, and the detection resolution of the detector 108 provided at the predetermined position can be controlled.

[0031] An example of a processing flow for adjusting the ratio of the electric field E2 to the magnetic field B2 of the deflector 110 using the ExB will be described with reference to Fig. 8 described. (S801)

[0032] A setting sample 901, as in Fig. 9 as an example, is positioned in the observation field of the scanning electron microscope. The ratio of the electric field E2 to the magnetic field B2 is adjusted based on the difference between the images captured by the beams. Therefore, for each position irradiated with multiple primary beams 104, a sample with a different shape is used as the adjustment sample 901. Fig. 9 shows, as an example, the adjustment sample 901 irradiated with nine primary beams 104, and the nine positions have different shapes. When multiple secondary beams 107 emitted from different positions of the adjustment sample 901 strike the same detection unit in the detector 108, an SEM image in which different shapes are mixed is obtained. That is, based on an evaluation of the SEM image of the adjustment sample 901, a degree of separation D of the secondary beams 107 can be calculated, for example, using the following equation. D=Si(i) / Si

[0033] Here, i is a sequential number of the multiple beams, Si is a total signal density of an i-th SEM image among the SEM images for each beam, and Si(i) is a signal density of an i-th beam included in Si. According to (Equation 3), D = 1 if the SEM image for each beam contains the signal density of the beam, and D = 0 if the SEM image for each beam does not contain the signal density of the beam.

[0034] By using a sample in which the same beam shape is formed at the position irradiated with the plurality of primary beams 104 instead of the adjustment sample 901, it is possible to calculate the separation degree D based on shape deviations in the SEM image for each beam. (S802)

[0035] Using the Fig. On the setting screen 1001 shown as an example in FIG. 10, the operator sets the ratio of the electric field E2 to the magnetic field B2 of the deflector 110. The setting screen 1001 includes a ratio input unit 1002, a capture start button 1003, an SEM image display unit 1004, a separation degree display unit 1005, and an OK button 1006. To set the ratio of the electric field E2 to the magnetic field B2 of the deflector 110, the ratio input unit 1002 is used. That is, the operator inputs the ratio of the electric field E2 to the magnetic field B2 into the ratio input unit 1002. Once the deflection angle θ2 obtained by the deflector 110 has been determined (Equation 2), the other value can be calculated based on the value of the electric field E2 or the magnetic field B2. Therefore, it is sufficient to enter either the value of the electric field E2 or the value of the magnetic field B2. (S803)

[0036] When the operator clicks the acquisition start button 1003, the SEM image of the adjustment sample 901 is acquired, and the control unit 120 evaluates the SEM image to calculate the separation degree of the secondary beams 107. For example, (Equation 3) is used to calculate the separation degree. The acquired SEM image is displayed on the SEM image display unit 1004, and the calculated separation degree is displayed on the separation degree display unit 1005. The lens or aligner can be adjusted in this step. (S804)

[0037] It is determined whether the separation degree calculated in S803 is within an allowable range. When the determination is performed by the operator, if the separation degree is within the allowable range, the OK button is clicked to start the processing flow in Fig. 8, and if the separation degree is not within the allowable range, the processing returns to S802 and the ratio is readjusted.

[0038] Through the processing flow described above, the ratio of the electric field E2 to the magnetic field B2 of the deflector 110 is adjusted so that the separation degree of the secondary beams 107 is within the allowable range, and the detection resolution can thus be improved. The control unit 120 can repeat the SEM image acquisition and separation degree calculation while changing the ratio of the electric field E2 to the magnetic field B2, and adjust the ratio so that the separation degree is within the predetermined allowable range.

[0039] When the voltage and current supplied to the deflector 110 to form the electric field E2 and the magnetic field B2 are V2 and I2, the deflection angle θ2 can be expressed by the following equation. θ2=aV2φ2+bI2φ20.5

[0040] Here, a and b are constants determined by the shape and configuration, for example, the size or the like, of the deflector 110, and θ2 is the energy of the secondary rays 107.

[0041] An energy dispersion Disp2 of the secondary beams 107 generated by the deflector 110 can be expressed by the following equation. Disp2=cV2φ2+d(I2φ2)0.5

[0042] Here, c and d are constants determined by the shape and configuration, such as the size or the like, of the deflector 110. To cancel the energy dispersion Disp1 of the secondary beams 107 generated by the beam separator 105 by the deflector 110, the following equation can be satisfied. Disp1+Disp2=0

[0043] Therefore, given the values ​​of the deflection angle θ2 and the energy dispersion Disp1, the voltage V2 and the current I2 supplied to the deflector 110 can be calculated based on (Equation 4) to (Equation 6). That is, the voltage V2 and the current I2 are calculated based on the deflection angle θ2 obtained by the deflector 110, the energy dispersion Disp1 generated by the beam separator 105, and the energy φ2 of the secondary beams 107. The electric field E2 and the magnetic field B2 of the deflector 110 can be adjusted using the calculated voltage V2 and current I2. By using the calculated voltage V2 and current I2, the adjustment of the electric field E2 and the magnetic field B2 of the deflector 110 can be simplified.

[0044] A modification of the scanning electron microscope according to the present embodiment will be described with reference to Fig. 11. In Fig. 1, a scanning electron microscope was described in which the ExB is used for the beam separator 105 and the primary beams 104 are straight to irradiate the sample 106. In Fig. 11 shows a scanning electron microscope in which an electric field sector or a magnetic field sector is used for the beam separator 105 to deflect the primary beams 104 and irradiate the sample 106. That is, Fig. 11 differs from Fig. 1 only by the beam separator 105; the other configurations are the same. The deflector 110 deflects the secondary beams 107 in the direction opposite to that of the beam separator 105.

[0045] The scanning electron microscope according to the present embodiment described above can reduce the positional shift between the secondary beams 107 generated in the beam separator 105. By reducing the positional shift between the secondary beams 107, the secondary beams 107 can be incident on the detection units of the detector 108, and therefore, the detection of the secondary beams 107 is not disturbed. Since the distortion of the beam shapes of the secondary beams 107 is also reduced, the detection resolution is improved. [Second embodiment]

[0046] In the first embodiment, a case was described where the inclination angle θ of the detector 108 with respect to the beam separator 105 is an arbitrary angle. In the present embodiment, a case is described where the beam separator 105 and the detector 108 are parallel. Components having the same functions as in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0047] An overall configuration of the scanning electron microscope according to the present embodiment will be described with reference to Fig. 12. In the present embodiment, the beam separator 105 and the detector 108 are arranged in parallel. That is, the inclination angle θ of the detector 108 with respect to the beam separator 105 is zero, and the detector 108 is arranged perpendicular to the direction of gravity. Also in Fig. 12, the positional shift between the secondary beams 107 generated in the beam separator 105 is corrected by deflecting the secondary beams 107 by the deflector 110 in a direction opposite to that of the beam separator 105. When θ = 0 is substituted into (Equation 1), θ2 = -θ1. Therefore, it is preferable that the deflection angle θ1 of the beam separator 105 and the deflection angle θ2 of the deflector 110 be equal absolute values.

[0048] With the scanning electron microscope according to the present embodiment described above, as in the first embodiment, the positional shift between the secondary beams 107 generated in the beam separator 105 can be reduced. Since the distortion of the beam shapes of the secondary beams 107 is also reduced, the detection resolution is improved. Furthermore, since the detector 108 is arranged perpendicular to the direction of gravity, the secondary beams 107 do not shift with respect to the detector 108 even when the detector 108 vibrates in the direction of gravity, and SEM images can be stably generated. [Third Embodiment]

[0049] In the first embodiment, a case was described where the secondary beams 107 are deflected by the deflector 110 in the direction opposite to that of the beam separator 105. In the present embodiment, a case is described where the ExB is used for the deflector 110 and the secondary beams 107 are straight. The components having the same functions as in the first embodiment are designated by the same reference numerals, and their descriptions are omitted.

[0050] An overall configuration of the scanning electron microscope according to the present embodiment will be described with reference to Fig. 13. In the present embodiment, the ExB is used for the deflector 110, and the secondary beams 107 pass straight through the deflector 110. That is, the deflection angle θ2 obtained by the deflector 110 is zero, and the beam separator 105, the deflector 110, and the detector 108 are arranged in a straight line. Fig. 13, while maintaining θ2 = 0, by adjusting the ratio of the electric field E2 to the magnetic field B2 in the deflector 110, the size of the beam shapes of the secondary beams 107 in the detector 108 is controlled to adjust the detection resolution of the detector 108. The ratio of the electric field E2 to the magnetic field B2 is determined according to the formula shown in Fig. The processing sequence shown in Figure 8 is set.

[0051] When the deflection angle θ2 = 0, it is somewhat difficult to correct the positional shift between the secondary beams 107. Therefore, in the present embodiment, as shown in Fig. 14, a deflector 110 forming an asymmetric electromagnetic field with respect to the secondary beams 107 may be used. Fig. The deflector 110 shown in Figure 14 has a plurality of electrodes or magnetic poles 1401 to 1405 arranged along the secondary beams 107.

[0052] The electrodes or magnetic poles 1401 to 1405 are partially turned on on one side, where the spreading of the electric field or magnetic field formed by the deflector 110 is controlled, and all the electrodes or magnetic poles are turned on on the other side. Fig. Fig. 14 illustrates, as an example, a case in which the electrodes or magnetic poles 1403a and 1401b to 1405b are turned on and the electrodes or magnetic poles 1401a, 1402a, 1404a, and 1405a are turned off. By operating the electrodes or magnetic poles 1401 to 1405 in this manner, the electromagnetic field is formed asymmetrically with respect to the secondary beams 107, and in Fig. 14, the portion affected by the asymmetric electromagnetic field becomes longer for the secondary beam 107c and shorter for the secondary beam 107a. By adjusting the portion affected by the asymmetric electromagnetic field, the positional shift between the secondary beams 107 is corrected.

[0053] With the scanning electron microscope according to the present embodiment described above, the formation of the asymmetric electromagnetic field can reduce the positional shift between the secondary beams 107 generated in the beam separator 105. Since the distortion of the beam shapes of the secondary beams 107 is also reduced, the detection resolution is improved. Furthermore, the secondary beams 107 pass straight through the deflector 110. Therefore, the beam separator 105, the deflector 110, and the detector 108 are arranged in a straight line, which simplifies the manufacturing of the scanning electron microscope.

[0054] As described above, several embodiments of the charged particle beam device according to the invention have been described. The invention is not limited to the above embodiments, and components can be modified and embodied without departing from the spirit of the invention. Several of the components disclosed in the above embodiments can be combined as appropriate. Furthermore, some components may be removed from all of the components shown in the above embodiments. List of reference symbols

[0055] 101 ... electron source, 102 ... electron beam, 103 ... multi-beam forming unit, 104 ... primary beam, 105 ... beam separator, 105a ... positive electrode, 105b ... negative electrode, 105c ... positive magnetic pole, 105d ... negative magnetic pole, 106 ... sample, 107 ... secondary beam, 108 ... detector, 110 ... deflector, 120 ... control unit, 201 ... force generated by electric field E, 202 ... force generated by magnetic field B, 301 ... influenced section, 302 ... plane, 701 ... intersection point, 901 ... adjustment sample, 1001 ... adjustment screen, 1002 ... ratio input unit, 1003 ... acquisition start button, 1004 ... SEM image display unit, 1005 ... Beam separation degree display unit, 1006 ... OK button, 1401 to 1405 ... multiple electrodes or magnetic poles

Claims

[1] Charged particle beam device with a charged particle beam source (101) designed to irradiate a sample (106) with a plurality of primary beams (104; 104a-c), a plurality of detectors (108) designed to detect secondary beams (107a-c) emitted by the sample in conjunction with the primary beams, a beam separator (105) configured to deflect the secondary beams in a direction different from that of the primary beams, and a deflector (110) provided between the beam separator and the detector for correcting a positional shift between the secondary beams generated in the beam separator together with a distortion of the beam shapes of the secondary beams generated in the beam separator, wherein the beam separator forms a first electric field (E) and a first magnetic field (B) which are perpendicular to each other in a plane perpendicular to the primary beams and causes the primary beams to move straight to deflect the secondary beams, wherein the deflector forms a second electric field (E2) and a second magnetic field (B2) which are perpendicular to each other, and wherein the strength of the second electric field and the strength of the second magnetic field are adjusted based on observation images that are different for each position irradiated with the primary beams. [2] Charged particle beam device with a charged particle beam source (101) designed to irradiate a sample (106) with a plurality of primary beams (104; 104a-c), a plurality of detectors (108) designed to detect secondary beams (107a-c) emitted by the sample in conjunction with the primary beams, a beam separator (105) configured to deflect the secondary beams in a direction different from that of the primary beams, and a deflector (110) provided between the beam separator and the detector for correcting a positional shift between the secondary beams generated in the beam separator together with a distortion of the beam shapes of the secondary beams generated in the beam separator, wherein the beam separator forms a first electric field (E) and a first magnetic field (B) which are perpendicular to each other in a plane perpendicular to the primary beams and causes the primary beams to travel straight to deflect the secondary beams, and the deflector is supplied with a voltage and a current for forming a second electric field (E2) and a second magnetic field (B2) which are perpendicular to each other, wherein values ​​of the voltage and current are adjusted based on an angle at which the secondary beams are deflected by the deflector, the energy dispersion of the secondary beams generated by the beam separator, and the energy of the secondary beams. [3] Charged particle beam device with a charged particle beam source (101) designed to irradiate a sample (106) with a plurality of primary beams (104; 104a-c), a plurality of detectors (108) designed to detect secondary beams (107a-c) emitted by the sample in conjunction with the primary beams, a beam separator (105) configured to deflect the secondary beams in a direction different from that of the primary beams, and a deflector (110) provided between the beam separator and the detector to correct a positional shift between the secondary beams generated in the beam separator, wherein an angle θ2 at which the secondary beams are deflected by the deflector is set based on an inclination angle θ of the detector with respect to the beam separator and wherein, when an angle θ1 at which the secondary rays are deflected by the beam separator is equal to the inclination angle θ of the detector with respect to the beam separator, the deflector forms an electric field (E2) and a magnetic field (B2) perpendicular to each other in a plane perpendicular to the secondary rays, causes the secondary rays to move straight, and corrects the chromatic aberration of the secondary rays. [4] A charged particle beam device according to claim 3, wherein the deflector (110) comprises a plurality of electrodes and a plurality of magnetic poles (1401-1405) arranged along the secondary beams (107a-c) and forms an electromagnetic field that is asymmetric with respect to the secondary beams.

Images