Charged particle beam device, method of controlling a charged particle beam device, and composite charged particle beam device

Abstract

The present application provides a charged particle beam device and a control method thereof, and a composite charged particle beam device, which can obtain a distortion-free, size-accurate, and scanned image of a sample surface equivalent to that before switching or changing, in the case of switching an acceleration mode and a deceleration mode of an objective lens or changing an applied voltage of an enhancer electrode constituting the objective lens. The charged particle beam device includes: a charged particle source that generates charged particles; a plurality of scanning electrodes that generate an electric field for deflecting the charged particles, the charged particles being emitted by applying an acceleration voltage to the charged particle source and an extraction voltage to an extraction electrode that extracts the charged particles; an electrostatic lens that is disposed between the plurality of scanning electrodes and a sample stage, and converges the charged particle beam deflected by the scanning electrodes; and a processing unit that acquires measurement conditions, and sets scanning voltages applied to the plurality of scanning electrodes based on the acquired measurement conditions, respectively.

Description

TECHNICAL FIELD

[0001] The present application relates to a charged particle beam device, a compound charged particle beam device, and a control method of a charged particle beam device. BACKGROUND

[0002] In processing of a sample shape represented by a sample preparation using a transmission electron microscope (TEM) with a focused ion beam (FIB) device, there is a demand to minimize damage to the sample caused by irradiation of the ion beam. Therefore, the sample is processed with the acceleration energy of the ion beam reduced to kV or less.

[0003] Specifically, in processing of a sample shape, a technique is known in which rough processing is performed at 30 kV and fine processing is performed at 10 kV (for example, refer to Patent Literature 1). Further, a technique is known in which a damage layer is efficiently removed by reducing the energy of the ion beam for fine processing and optimizing the incident angle of the sample by the sample shape (for example, refer to Patent Literature 2). Further, a technique is known in which the acceleration voltage is reduced in order to reduce the damage layer (for example, refer to Patent Literature 3).

[0004] However, when the acceleration voltage of the focused ion beam is reduced, the increase in beam blur amount due to chromatic aberration and the widening of the beam profile by Coulomb interaction become significant. That is, when used with the acceleration voltage reduced, the chromatic aberration increases and the ion beam cannot be sufficiently converged. Therefore, a fine ion probe cannot be obtained. In order to solve this problem, a technique is known in which the acceleration lens action and the deceleration lens action are selectively applied according to the acceleration voltage, so that the chromatic aberration hardly changes (for example, refer to Patent Literature 4).

[0005] Further, a beam booster technique is known in which the potential energy of the intermediate portion of the optical system is increased and is lowered by the objective lens (for example, refer to Patent Literature 5, Non-Patent Literature 1).

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent No. 3333731

[0009] Patent Literature 2: Japanese Patent No. 5142240

[0010] Patent Literature 3: Japanese Patent No. 5537050

[0011] Patent Literature 4: Japanese Patent Application Laid-Open No. 5-35540

[0012] Patent Literature 5: Japanese Patent Application Laid-Open No. 2007-103108

[0013] Patent Literature 6: Japanese Patent No. 3544438

[0014] Patent Literature 7: Japanese Patent No. 5969229

[0015] Non Patent Literature

[0016] Non Patent Literature 1: Michael Rauscher and Erich Plies, "Low Energy focused ion beam system design", Journal of Vacuum Science & Technology A, American Vacuum Society, 2006, 24(4), p. 1055-1066 SUMMARY

[0017] PROBLEMS TO BE SOLVED BY THE INVENTION

[0018] The focused ion beam is sometimes used at a high acceleration voltage (e.g., 30 kV) at the time of processing, etching, and the like, and is used at a low acceleration voltage (e.g., 1 kV to 5 kV) in order to remove a damage layer caused by the processing at the time of finishing.

[0019] Further, the operation mode of the optical system is sometimes switched from the deceleration mode to the acceleration mode while the acceleration voltage is lowered. In the case where the mode of the optical system is switched while the acceleration voltage is lowered, the principal plane of the objective lens is changed.

[0020] Further, a booster potential is sometimes applied while the acceleration voltage is lowered. In the case where the booster potential is applied while the acceleration voltage is lowered, the principal plane of the objective lens is changed.

[0021] Here, the change of the principal plane of the objective lens will be described.

[0022] Figure 1is a schematic diagram for explaining movement of a principal plane of an objective lens due to switching of an acceleration mode and a deceleration mode of the objective lens. The objective lens OL is configured to include an incident-side electrode IE, a central electrode CE, and an exit-side electrode OE. A lens principal plane in the case of the acceleration mode is represented by a virtual objective lens 10a, and a lens principal plane in the case of the deceleration mode is represented by a virtual objective lens 10b. The virtual objective lens is a concept used for convenience of explanation of an ion beam trajectory. An actual lens is an electrostatic lens formed by an electric field generated between the incident-side electrode IE, the central electrode CE, and the exit-side electrode OE by applying a voltage to the central electrode CE. In a case where a focal point is connected to the same point of a sample S, when the acceleration mode and the deceleration mode are switched, the ion beam trajectory in the objective lens OL changes. Specifically, as shown in Figure 1 , the trajectory on the lower side of the objective lens OL changes more in the case of the deceleration mode than in the case of the acceleration mode. As a result, the lens principal plane in the deceleration mode represented by the virtual objective lens 10b is located on the lower side of the lens principal plane in the acceleration mode represented by the virtual objective lens 10a.

[0023] Figure 2 is a schematic diagram for explaining movement of a principal plane of an objective lens due to application of a booster voltage. The objective lens OL is configured to include an incident-side electrode IE, a central electrode CE, and an exit-side electrode OE. A lens principal plane when the booster voltage is zero is represented by a virtual objective lens 10c, and a lens principal plane when the booster voltage is applied is represented by a virtual objective lens 10d. In a case where a focal point is connected to the same point of a sample S, by applying the booster voltage, the ion beam trajectory in the objective lens OL changes. Specifically, as shown in Figure 2 , the trajectory on the lower side of the objective lens OL changes more in the case where the booster voltage is applied than in the case where the booster voltage is not applied. As a result, the lens principal plane when the booster voltage is applied represented by the virtual objective lens 10d is located on the lower side of the lens principal plane when the booster voltage is not applied represented by the virtual objective lens 10c.

[0024] An explanation is made of a convergent ion beam device having two-stage scanning electrodes provided in a front stage of an objective lens OL as beam scanning electrodes. Here, an explanation is made of a case where movement of a lens principal plane is accompanied. The structure in which the two-stage scanning electrodes are provided in the front stage of the objective lens OL enables the objective lens OL to be disposed close to a sample S, and thus, the focal length can be reduced. Therefore, blurring due to lens aberration can be suppressed, and thus, this structure is generally used.

[0025] Figure 3 is a diagram showing an example 1 of scanning of a beam when the two-stage scanning electrodes are used. In Figure 3 , a virtual objective lens 10e, an incident-side electrode IE, a central electrode CE, an exit-side electrode OE, a first scanning electrode 44, and a second scanning electrode 45 are shown. Figure 3A case where the booster voltage is not applied is shown. The lens main surface when the booster voltage is zero is indicated by a virtual objective lens 10e. As shown in Figure 3 , the beam B is scanned in a manner that the beam passes through the lens main surface on the optical axis by using the 2nd stage scanning electrode. However, the beam is scanned over the objective lens OL by the 2nd stage scanning electrode provided in the front stage of the objective lens OL, and thus the scanned beam can be affected by the lens.

[0026] Figure 4 is a diagram showing an example 2 of scanning of the beam when the 2nd stage scanning electrode is used. In Figure 4 , a virtual objective lens 10f, an incident side electrode IE, a central electrode CE, an outgoing side electrode OE, a 1st stage scanning electrode 44, and a 2nd stage scanning electrode 45 are shown. Figure 4 A case where the booster voltage is applied is shown. The lens main surface when the booster voltage is applied is indicated by a virtual objective lens 10f. In the case where the booster voltage is applied, the orbit of the objective lens OL changes greatly compared to the case where the booster voltage is not applied. As a result, the lens main surface when the booster voltage is applied, which is indicated by the virtual objective lens 10f, is located below the lens main surface when the booster voltage is not applied, which is indicated by the virtual objective lens 10e. Figure 3

[0027] Now, in the case where the beam B is scanned in a manner that the beam passes through the lens main surface on the optical axis by using the same voltage as the 2nd stage scanning electrode shown in Figure 3 , the position where the beam passes through the main surface of the virtual objective lens 10e. However, since the main surface moves to the virtual objective lens 10f, the beam cannot pass through the main surface and is affected by the lens. As shown in Figure 4 , since the scanned beam is affected by the lens, the orbit of the beam is refracted. Since the orbit of the beam is refracted, the desired beam scan width based on the scanning cannot be obtained. For example, with respect to the amplitude of the beam, the scan width of the beam when the booster voltage is applied is w2 with respect to the scan width wl of the beam when the booster voltage is not applied. In the case where the influence of the lens is large, a scanned image having distortion is obtained. Or even in the case where the distortion is small, the linearity of the scan distance is lost, and the dimensional accuracy of the scanned image is affected.

[0028] That is, in the case where the mode of the lens is changed, the orbit of the beam changes, and thus the main surface of the lens moves, and thus the scanning in a manner that the beam passes through the lens main surface on the optical axis cannot be performed at times. As a result, the linearity of the scanning cannot be ensured at times. Since the linearity of the scanning cannot be ensured, a distorted scanned image of the sample surface can be obtained and the sample surface cannot be observed with dimensional accuracy, or accurate processing by the beam scanning cannot be performed.

[0029] ​For this problem, even if the method described in Patent Literature 6 is applied, it cannot be solved. In Patent Literature 6, it is described that an application voltage to be applied to an objective lens is stored in a computer in advance and a plurality of processes are performed. However, the position of a scanning electrode becomes below the objective lens, and the scanning electrode is one stage, and thus the structure is different from the present application. In addition, the control of a plurality of scanning electrodes is not described. Therefore, it cannot be analogized how the problem occurs and how the plurality of scanning voltages is set.

[0030] For this problem, even if the method described in Patent Literature 7 is applied, it cannot be solved. The control object in Patent Literature 7 is a convergence voltage of a convergence lens, and in Patent Literature 7, adjustment of a beam current by setting the convergence voltage is described as an object. In Patent Literature 7, a plurality of scanning electrodes is not described, and scanning of a beam beyond an objective lens is not described. Therefore, it cannot be analogized how the problem occurs and how the plurality of scanning voltages is set.

[0031] The present application is achieved in view of the above points, and an object thereof is to provide a charged particle beam device, a compound charged particle beam device, and a control method of a charged particle beam device, in which in a charged particle beam device provided with an electrostatic lens such as an objective lens OL and a two-stage scanning electrode provided in a front stage of the electrostatic lens, in a case where switching between an acceleration mode and a deceleration mode of the objective lens or a change in an application voltage of an enhancer electrode constituting the objective lens is performed, a distortion-free, size-accurate, scanned image of a sample surface equivalent to that before the switching or the change can be obtained.

[0032] Means for solving the problem

[0033] In order to solve the above problems and achieve the related objects, the present application adopts the following solutions.

[0034] (1) A charged particle beam device according to an aspect of the present application includes: a charged particle source that generates charged particles; a plurality of scanning electrodes that generate an electric field for deflecting the charged particles to the charged particles emitted by applying an acceleration voltage to the charged particle source and applying an extraction voltage to an extraction electrode that extracts the charged particles; an electrostatic lens that is disposed between the plurality of scanning electrodes and a sample stage, and converges the charged particle beam deflected by the scanning electrodes; and a processing unit that acquires measurement conditions, and sets scanning voltages to be applied to the plurality of scanning electrodes based on the acquired measurement conditions.

[0035] (2) The charged particle beam device according to (1) above, wherein the processing section acquires information on a plurality of determined scan voltages that correspond to the acquired measurement condition from scan voltage information that associates a measurement condition with information on a determined scan voltage applied by the plurality of scan electrodes, and sets the plurality of scan voltages based on the acquired information on the plurality of determined scan voltages.

[0036] (3) The charged particle beam device according to (1) or (2) above, wherein the plurality of scan electrodes include a first scan electrode that applies a first scan voltage to the charged particle beam, and a second scan electrode that is disposed between the first scan electrode and the sample stage and applies a second scan voltage to the charged particle beam.

[0037] (4) The charged particle beam device according to any one of (1) to (3) above, wherein the measurement condition includes information on a determined acceleration voltage and information on a determined operation mode.

[0038] (5) The charged particle beam device according to any one of (1) to (3) above, wherein the charged particle beam device has a beam booster voltage application section that is disposed between the charged particle source and the sample stage and applies a beam booster voltage to the charged particle beam, and the measurement condition includes information on a determined acceleration voltage and information on a determined beam booster voltage.

[0039] (6) The charged particle beam device according to (5) above, wherein the processing section acquires information on a determined beam booster voltage that corresponds to the acquired measurement condition from beam booster voltage information that associates a measurement condition with information on a determined beam booster voltage applied by the beam booster voltage application section, and sets the beam booster voltage information based on the information on the acquired determined beam booster voltage information.

[0040] (7) A compound charged particle beam device that is the compound charged particle beam device according to (5) above, further comprising an electron beam barrel, wherein the processing section sets the beam booster voltage based on the acceleration voltage, a focal point of the charged particle beam that is converged by the electrostatic lens, and an irradiation point of an electron beam that is irradiated by an electron beam irradiation section.

[0041] (8) The compound charged particle beam device according to (7) above, wherein the focal point of the charged particle beam that is converged by the electrostatic lens coincides with the irradiation point of the electron beam.

[0042] (9) In the compound charged particle beam device according to (7) or (8) above, the processing section acquires information of a determined beam booster voltage that matches the acquired measurement condition from beam booster voltage information in which measurement conditions are associated with information of a beam booster voltage applied by the beam booster voltage application section, and sets the beam booster voltage based on the information of the acquired determined beam booster voltage information.

[0043] (10) A control method of a charged particle beam device according to an aspect of the present invention includes the steps of applying an acceleration voltage to a charged particle source and applying an extraction voltage to an extraction electrode that extracts charged particles, whereby the charged particle source emits charged particles; acquiring a measurement condition, and setting a plurality of scan voltages applied to a plurality of scan electrodes that generate an electric field for deflecting the charged particles based on the acquired measurement condition; applying the scan voltages to the plurality of scan electrodes based on each of the plurality of set scan voltages; and converging the charged particles deflected by the scan voltages by an electrostatic lens disposed between the plurality of scan electrodes and a sample stage.

[0044] Effects of the Invention

[0045] According to the present invention, in a charged particle beam device provided with an electrostatic lens such as an objective lens OL and a two-stage scan electrode disposed in front of the electrostatic lens, in a case where switching between acceleration and deceleration modes of the objective lens or changing of an applied voltage of a booster electrode constituting the objective lens is performed, a scan image of a sample surface that is distortionless and accurate in size equivalent to that before the switching or changing can be obtained. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is a diagram for explaining movement of a main surface of an objective lens caused by switching between acceleration and deceleration modes of the objective lens.

[0047] Figure 2 is a diagram for explaining movement of a main surface of an objective lens caused by application of a booster voltage.

[0048] Figure 3 is a diagram showing an example 1 of scanning of a beam when a two-stage scan electrode is used.

[0049] Figure 4 is a diagram showing an example 2 of scanning of a beam when a two-stage scan electrode is used.

[0050] Figure 5 is a diagram showing an example of a structure of a charged particle beam device according to the first embodiment.

[0051] Figure 6Fig. 1 is a diagram showing an example of a structure of a control section in a charged particle beam device according to the present embodiment.

[0052] Figure 7 Fig. 2 is a diagram showing an example of scan voltage information.

[0053] Figure 8 Fig. 3 is a diagram showing an example of a first electrode, a second electrode, an incident-side electrode, an intermediate electrode, and an exit-side electrode in the charged particle beam device according to the present embodiment.

[0054] Figure 9 Fig. 4 shows an example of a trajectory of an ion beam in the structure shown in Fig. 3. Figure 8

[0055] Figure 10 Fig. 5 is a flowchart showing an example of an operation of the charged particle beam device according to the present embodiment.

[0056] Figure 11 Fig. 6 is a diagram showing an example of a structure of a control section in a charged particle beam device according to a modification 1 of the present embodiment.

[0057] Figure 12 Fig. 7 is a diagram showing an example of scan voltage information.

[0058] Figure 13 Fig. 8 is a diagram showing an example of a relationship between a range of an acceleration voltage value Eacc and a beam enhancer voltage value Eb in the charged particle beam device according to the modification 1 of the first embodiment.

[0059] Figure 14 Fig. 9 shows an example of a trajectory of an ion beam.

[0060] Figure 15 Fig. 10 shows an example of a trajectory of an ion beam.

[0061] Figure 16 Fig. 11 is a flowchart showing an example of an operation of the charged particle beam device according to the modification 1 of the first embodiment.

[0062] Figure 17 Fig. 12 is a diagram showing an example of a structure of a control section in a charged particle beam device according to a modification 2 of the present embodiment.

[0063] Figure 18 Fig. 13 is a flowchart showing an example of an operation of the charged particle beam device according to the modification 2 of the first embodiment.

[0064] Figure 19 Fig. 14 is a diagram showing an example of a structure of a control section in a composite charged particle beam device according to a second embodiment.

[0065] Explanation of Reference Numerals

[0066] ​D…compound charged particle beam apparatus, D1…charged particle beam apparatus, D2…scanning electron microscope, 1…ion source control section, 10…acceleration power supply, 3…condenser lens central electrode, 4b…beam booster, 5…objective lens central electrode, 9, 9a, 9b, 9c…control section, 90, 90a, 90b, 90c…processing section, 91, 91a, 91b, 91c…storage section, 92, 92a, 92b, 92c…scanning voltage information, 93, 93a, 93b, 93c…beam booster voltage information, 41…alignment electrode, 42…astigmatism correction electrode, 43…blanking electrode, 44…1st scanning electrode, 45…2nd scanning electrode, 60…MCU. DETAILED DESCRIPTION

[0067] Next, a charged particle beam apparatus, a compound charged particle beam apparatus, and a control method of a charged particle beam apparatus according to the present embodiment will be described with reference to the drawings. The following described embodiment is only an example, and the embodiment to which the present application is applied is not limited to the following described embodiment.

[0068] In addition, in all the drawings for describing the embodiment, the same reference numerals are used for parts having the same function, and repeated description is omitted.

[0069] Further, "based on XX" in the present application means "at least based on XX", and also includes a case where based on other elements in addition to XX. Further, "based on XX" is not limited to a case of directly using XX, and also includes a case of using contents obtained by performing an operation, processing, and the like on XX. "XX" is an arbitrary element (for example, arbitrary information).

[0070] (1st Embodiment)

[0071] Figure 5 is a drawing showing an example of the structure of a charged particle beam apparatus according to the 1st embodiment.

[0072] The charged particle beam apparatus D1 includes a charged particle beam apparatus main body Da, a beam booster control section 6, a beam booster power supply section 7, a lens power supply section 8, a control section 9, a tank control module 12, a host PB section 13, a vacuum control section 14, a stage control section 15, a scanning plate 16, and a personal computer (PC) 17.

[0073] The convergent ion beam device main body Da has an ion source control section 1, an ion emitter E, an extraction electrode 2, a condenser lens central electrode 3, an enhancer tube 4a, and an objective lens central electrode 5. The convergent ion beam device main body Da converges the ion beam B after accelerating the ion beam B to an acceleration voltage Vacc by a condenser lens composed of an electric field generated between the condenser lens central electrode 3, the extraction electrode 2, and the enhancer tube 4a, and an objective lens composed of an electric field generated between the objective lens central electrode 5, the enhancer tube, and a ground electrode, and irradiates the sample SP1 on a sample stage. The sample SP1 is configured in a state of being grounded.

[0074] The ion source control section 1 controls emission of the charged particle beam. An example of the charged particle beam is the ion beam B. Hereinafter, the description will be continued with respect to the case where the ion beam B is applied as the charged particle beam. The ion source control section 1 has an extraction power supply 11 and an acceleration power supply 10.

[0075] The ion emitter E is a charged particle source that generates charged particles. The ion emitter E has a metal with a sharp tip, and the tip of the metal is configured as a liquid metal ion source that is wetted with, for example, liquid metal gallium. In addition, instead of the liquid metal, a gas such as helium, neon, oxygen, nitrogen, hydrogen, or the like can be supplied to the ion emitter E to be a gas field ionization type ion source. In addition, as the charged particle supply section, the ion emitter E can also use an inductively coupled plasma ion source, an electron cyclotron resonance plasma ion source, or a Penning ion gauge (PIG) plasma ion source.

[0076] The extraction power supply 11 extracts gallium ions from the tip of the ion emitter E as charged particles by applying an extraction voltage Vext between the tip of the ion emitter E and the extraction electrode 2.

[0077] The acceleration power supply 10 forms the ion beam B by applying an acceleration voltage Vacc to the charged particles generated by the ion emitter E and accelerates the formed ion beam B. An example of the acceleration voltage Vacc is 30 kV at the maximum. However, in order to minimize damage to the sample caused by ion beam irradiation, the acceleration voltage can also be set for each processing step of the convergent ion beam. For example, the acceleration voltage can be set to 30 kV in rough processing and to 1 kV, 0.5 kV, which is lower than in rough processing, in finish processing.

[0078] The condenser lens including the condenser lens central electrode 3 converges the ion beam B accelerated by the acceleration voltage Vacc applied by the acceleration power supply 10. Here, the condenser lens converges the passing ion beam B using an electric field formed by applying a condenser lens voltage Vcl to the condenser lens central electrode 3 by a condenser lens power supply 80 of a lens power supply section 8.

[0079] The booster tube 4a applies a beam booster voltage Vb to the ion beam B converged by the condenser lens. The booster tube 4a is provided between the condenser lens central electrode 3 and the objective lens central electrode 5. The booster tube 4a suppresses an increase in the amount of blurring of the beam caused by chromatic aberration, and a broadening of the beam profile caused by Coulomb interaction, by increasing the potential energy of the ion beam B that has passed through the condenser lens. The booster tube 4a is provided with a beam booster 4b. Here, the beam booster 4b is an example of a beam booster voltage application section. The beam booster 4b is provided with an alignment electrode 41, a stigmator electrode 42, a blanking electrode 43, a first scanning electrode 44, and a second scanning electrode 45.

[0080] The alignment electrode 41 is disposed between the condenser lens central electrode 3 and the stigmator electrode 42. The alignment electrode 41 is connected to an alignment power supply 61 of the beam booster control section 6. The alignment electrode 41 corrects the deviation of the optical axis of the ion beam B that has passed through by applying a voltage to the ion beam B.

[0081] The stigmator electrode 42 is disposed between the alignment electrode 41 and the blanking electrode 43. The stigmator electrode 42 is connected to a stigmator power supply 62 of the beam booster control section 6. The stigmator electrode 42 corrects the distortion of the cross-sectional shape of the ion beam B that has passed through by applying a voltage to the ion beam B, thereby making it circular.

[0082] The blanking electrode 43 is disposed between the stigmator electrode 42 and the first scanning electrode 44. The blanking electrode 43 is connected to a blanking power supply 63 of the beam booster control section 6. The blanking electrode 43 deflects the ion beam B that has passed through by applying a voltage thereto, so that the ion beam B does not irradiate the sample SP1.

[0083] The first scanning electrode 44 is disposed between the blanking electrode 43 and the second scanning electrode 45. The blanking electrode 43 is connected to a deflection power supply 64 of the beam booster control section 6. The first scanning electrode 44 scans the ion beam B that has passed through on the sample SP1 by applying a voltage thereto.

[0084] The second scanning electrode 45 is disposed between the first scanning electrode 44 and the objective lens central electrode 5. The second scanning electrode 45 is connected to the deflection power supply 64 of the beam booster control section 6. The second scanning electrode 45 scans the ion beam B that has passed through on the sample SP1 by applying a voltage thereto.

[0085] The objective lens central electrode 5 is disposed between the second scanning electrode 45 and the sample stage. The objective lens converges the ion beam B to which the beam booster voltage Vb has been applied by the beam booster 4b, and irradiates it on the sample SP1. Here, the objective lens converges the ion beam B that has passed through using an electric field formed by applying an objective lens voltage Vol to the objective lens central electrode 5 by the objective lens power supply 81 included in the lens power supply section 8. Furthermore, the objective lens separates the potential difference ion beam B and slows it down.

[0086] The beam booster control section 6 controls the beam booster 4b. The beam booster control section 6 has an MCU 60, an alignment power supply 61, a stigmator power supply 62, a blanking power supply 63, a deflection power supply 64, and a high voltage floating section 66.

[0087] The memory control unit (MCU) 60 controls the alignment power supply 61, the stigmator power supply 62, and the blanking power supply 63 based on the beam booster voltage Vb set by the beam booster power supply section 7. The MCU 60 controls the deflection power supply 64 based on the value of the first voltage VdefU, i.e., the first voltage value EdefU, which is the voltage applied to the first scan electrode 44 set by the control section 9, and the value of the second voltage VdefL, i.e., the second voltage value EdefL, which is the voltage applied to the second scan electrode 45.

[0088] The alignment power supply 61 applies a voltage to the alignment electrode 41. The stigmator power supply 62 applies a voltage to the stigmator electrode 42. The blanking power supply 63 applies a voltage to the blanking electrode 43. The deflection power supply 64 applies a voltage to the first scan electrode 44 and the second scan electrode 45.

[0089] The high voltage floating section 66 supplies a scan signal to the deflection power supply 64 under the control of the scan plate 16. The scan signal is a signal for adjusting the position at which the ion beam B is irradiated to the sample SP1. The high voltage floating section 66 constitutes a scan system SS together with the scan plate 16.

[0090] The beam booster power supply section 7 sets the beam booster voltage Vb based on the control of the control section 9.

[0091] The lens power supply section 8 has a condenser lens power supply 80 and an objective lens power supply 81. The condenser lens power supply 80 applies a voltage to the condenser lens central electrode 3. The objective lens power supply 81 applies a voltage to the objective lens central electrode 5.

[0092] The control section 9 controls the beam booster power supply section 7 based on the acceleration voltage value Eacc of the acceleration voltage Vacc supplied from the PC 17. Here, the acceleration voltage value Eacc is supplied from the PC 17 to the control section 9 via the host PB 13. The control section 9 will be described in detail later.

[0093] The PC 17 accepts various operations from a user of the charged particle beam device Dl. The PC 17 supplies an operation signal to the ion source control section 1 via the tank control module 12. The PC 17 supplies an operation signal to the beam enhancer control section 6 and the control section 9 via the host PB 13. Here, in the operation signal, for example, information indicating a value of the acceleration voltage Vacc, that is, an acceleration voltage value Eacc is included. Further, the PC 17 controls the vacuum control section 14 that controls a vacuum state of the charged particle beam device Dl and the stage control section 15 that controls a stage on which the sample SP 1 is placed.

[0094] In the present embodiment, the case where the beam enhancer voltage Vb set for the beam enhancer power supply section 7 is zero will be described as an example. The alignment electrode 41, the stigmator electrode 42, and the blanking electrode 43 included in the beam enhancer 4b can be omitted. Further, the alignment power supply 61, the stigmator power supply 62, and the blanking power supply 63 included in the beam enhancer control section 6 can be omitted. The beam enhancer power supply section 7 can be omitted.

[0095] Next, the structure of the control section 9 will be described in detail.

[0096] Figure 6 is a view showing an example of the structure of the control section in the charged particle beam device of the present embodiment. The control section 9 is provided with a processing section 90 and a storage section 91. The storage section 91 stores scan voltage information 92.

[0097] The processing section 90 derives a value of the first voltage VdefU, that is, a first voltage value EdefU, and a value of the second voltage VdefL, that is, a second voltage value EdefL, based on the acceleration voltage value Eacc supplied from the PC 17, information indicating the operation mode, and the scan voltage information 92 read out from the storage section 91. The processing section 90 outputs the derived first voltage value EdefU and the second voltage value EdefL to the MCU 60.

[0098] The scan voltage information 92 stores, in association with information that determines the value of the first voltage VdefU, that is, the first voltage value EdefU, and the value of the second voltage VdefL, that is, the second voltage value EdefL, for each value of the acceleration voltage Vacc, that is, the acceleration voltage value Eacc.

[0099] Figure 7 is a view showing an example of the scan voltage information. In the example shown in Figure 7 The scan voltage information 92 associates, for each of the acceleration voltage values Eacc of 5 kV, 10 kV, and 30 kV, the operation mode, the ratio of the first voltage value EdefU to the second voltage value EdefL, and the first voltage value EdefU. Here, the operation mode includes the acceleration mode and the deceleration mode.

[0100] The acceleration mode is the operating mode in which the ion beam B is accelerated within the objective lens compared to its initial velocity before incident on the lens, thus converging it. The deceleration mode is the operating mode in which the ion beam B is decelerated within the objective lens compared to its initial velocity before incident on the lens, thus converging it. In both modes, the emitted beam reaches the same velocity as the incident beam. For example... Figure 7 As shown, in the scan voltage information 92, the accelerating voltage value "30kV", the operating mode "acceleration mode", the ratio of the first voltage value to the second voltage value "1:0.953", and the first voltage value "210V" are associated, while the accelerating voltage value "30kV", the operating mode "deceleration mode", the ratio of the first voltage value to the second voltage value "1:0.942", and the first voltage value "228V" are associated. Here, as an example, accelerating voltage values ​​Eacc of 5kV, 10kV, and 30kV are shown, but it is not limited to this example; accelerating voltage values ​​Eacc can also be other than 5kV, 10kV, and 30kV. In addition, the first voltage value is the value that assigns a specific scan width to the sample, for example, the value when scanning at 0.5mm.

[0101] Here, the process of passing the ion beam B through the principal surface of the objective lens on the optical axis will be explained.

[0102] Figure 8 This diagram illustrates an example of the first scanning electrode, the second scanning electrode, the incident-side electrode constituting the objective lens, the intermediate electrode, and the exit-side electrode in the charged particle beam apparatus of this embodiment. Figure 8 The image shows an intensifier tube 4a, a first scanning electrode 44, a second scanning electrode 45, an incident electrode 5c, an intermediate electrode 5b, and an exit electrode 5a. Figure 8 In this design, the short side direction of the booster tube 4a is defined as the X-axis, and the long side direction of the booster tube 4a is defined as the Z-axis. Furthermore, on the Z-axis, the direction of exit from the direction of incident ion beam B is defined as positive.

[0103] Next, the orbit of ion beam B will be explained.

[0104] Figure 9 Show Figure 8 An example of the ion beam orbitals in the structure shown. Figure 9 In the middle, the X-axis and Z-axis are as follows Figure 8 As shown. In Figure 9 The diagram shows the case where the operating mode is acceleration mode (acceleration lens system), the acceleration voltage is 5kV, and there is no beam intensifier 4b (the beam intensifier voltage is 0 [V]).

[0105] exist Figure 9The diagram does not show the deflection electric field formed based on the first scanning electrode in the region with Z-axis values ​​of -120 mm to -110 mm, the deflection electric field formed based on the second scanning electrode in the region with Z-axis values ​​of -90 mm to -70 mm, and the converging electric field formed based on the objective lens in the region with Z-axis values ​​of -40 mm to -5 mm. The diagram shows the trajectory of the ion beam B from its incidence at the first scanning electrode to its arrival at the sample surface and the result of applying the regression line to the trajectory of the ion beam B.

[0106] according to Figure 9 As shown in the left figure, the trajectory of ion beam B intersects with the result of applying the regression line to ion beam B on the image plane.

[0107] Figure 9 The right figure shows in Figure 9 The left image shows a magnified view of the trajectory of ion beam B, where the regression line is applied to the trajectory of ion beam B, resulting in a Z=0 [mm] plot. According to... Figure 9 In the right figure, at Z = 0 [mm] on the sample surface, X = 0.5 mm. The ion beam B, while passing through the converging electric field of the objective lens located in the region of -40 mm to -5 mm on the Z-axis, is considered to have a straight trajectory. Therefore, the ion beam B reaches the sample surface with almost no effect from the objective lens.

[0108] Since the beam passing through the principal plane on the optical axis of the lens travels in a straight line, it can be considered that... Figure 9 The trajectory of ion beam B shown passes through the principal plane of the objective lens. At this time, the ratio of the first voltage value EdefH to the second voltage value EdefL (the ratio of the upper and lower levels of DEF) (first voltage value EdefH : second voltage value EdefL) is 1 : 0.953.

[0109] When the first voltage value EdefH = 35 [V] and the second voltage value EdefL = -33.36 [V], the swing of the ion beam B's orbit in the X-axis direction becomes 0.5 [mm]. It should be noted that the polarities of the first and second voltage values ​​need to be reversed.

[0110] Furthermore, regarding the Y-axis direction perpendicular to the paper, the same first and second scanning electrodes as the X-axis can be used to perform scanning by applying a first voltage value and a second voltage value respectively, which is not illustrated. Scanning of the XY plane can be performed using raster scanning. When the polarities of the first and second voltage values ​​are reversed, scanning occurs in opposite directions along each axis.

[0111] A +0.5 mm scan was performed on the sample with a first voltage value EdefH = 35 [V] and a second voltage value EdefL = -33.36 [V].

[0112] A scan of -0.5 mm was performed on the sample with the first voltage value EdefH = -35 [V] and the second voltage value EdefL = 33.36 [V].

[0113] In the above example, a scan of 1 mm was performed on the region of ±0.5 mm.

[0114] The trajectory of the ion beam was also derived for the case where the operation mode was the deceleration mode, the acceleration voltage value Eacc was 5 kV, and there was no beam enhancer 4b (beam enhancer voltage value was 0 [V]). It was found that the trajectory on the sample surface coincided with the regression straight line in the case where the ratio of the first voltage value EdefH to the second voltage value EdefL (upper-to-lower ratio of DEF) (first voltage value EdefH : second voltage value EdefL) was 1 : 0.942. In order to make the swing in the X-axis direction of the trajectory of the ion beam B 0.5 [mm] (field of view of the scan image: 1 [mm]), the first voltage value EdefH = 38 [V] was made.

[0115] According to the above, the scan voltage information 92 shown in FIG. 8 was derived. Figure 7

[0116] Next, the process of setting the first voltage value EdefU and the second voltage value EdefL based on the acceleration voltage and the operation mode will be described with respect to the operation of the charged particle beam device.

[0117] Figure 10 is a flowchart showing an example of the operation of the charged particle beam device of the present embodiment.

[0118] (Step S1)

[0119] In the charged particle beam device D1, the processing section 90 acquires the acceleration voltage value Eacc and the information indicating the operation mode from the PC 17.

[0120] (Step S2)

[0121] In the charged particle beam device D1, the processing section 90 reads the scan voltage information 92 from the storage section 91. The processing section 90 acquires the ratio of the first voltage value to the second voltage value and the first voltage value associated with the combination of the acquired acceleration voltage value Eacc and the information indicating the operation mode from the read scan voltage information 92.

[0122] (Step S3)

[0123] In the charged particle beam device D1, the processing section 90 derives the second voltage value based on the acquired ratio of the first voltage value to the second voltage value and the first voltage value.

[0124] (Step S4)

[0125] ​In the charged particle beam device D1, the processing section 90 sets the first voltage value and the derived second voltage value to the MCU 60. Note here that it is necessary to reverse the polarity of the first voltage value and the second voltage value.

[0126] Further, the first voltage value is a value at which a specific scan width is imparted on the sample, for example, a value at which a scan of 0.5 mm is performed. Also, when the polarity of the first voltage value and the second voltage value is reversed, a scan is performed in the opposite direction.

[0127] After implementation (step S4), it is possible to change to an arbitrary scan width. For example, in the case of performing a scan of 0.1 mm, it is possible to reduce the first voltage value and the second voltage value to 1 / 5. The first voltage value and the second voltage value are changed based on the ratio of the first voltage value to the second voltage value, and thus, it is possible to obtain an accurate scan image without distortion.

[0128] In the above-described embodiments, a case in which the acceleration voltage value, the information indicating the operation mode, the information indicating the ratio of the first voltage value to the second voltage value, and the first voltage value are stored in association in the scan voltage information 92 was described, but is not limited to this example. For example, it is also possible to store the acceleration voltage value, the information indicating the operation mode, the information indicating the ratio of the first voltage value to the second voltage value, and the second voltage value in association in the scan voltage information 92, and it is also possible to store the acceleration voltage value, the information indicating the operation mode, the first voltage value, and the second voltage value in association in the scan voltage information 92.

[0129] In the above-described embodiments, a case in which the control section 9 is provided with the storage section 91 was described, but is not limited to this example. For example, the storage section 91 can also be provided outside the charged particle beam device D1. In a case in which the storage section 91 is provided outside the charged particle beam device D1, for example, the storage section 91 can also be provided as an external storage device or a cloud server.

[0130] Further, instead of storing the scan voltage information 92, it is also possible to store, in the storage section 91, an operation formula for deriving the first scan voltage VdefU and the second scan voltage VdefL based on the acceleration voltage value Eacc and the information indicating the operation mode. In this case, the control section 9 can also set based on these operation formulas, the first scan voltage VdefU and the second scan voltage VdefL which are derived.

[0131] In the above-described embodiments, it is also possible to omit a part of the information included in the scan voltage information 92. For example, since there is almost no use of an acceleration voltage of 5 [kV] and a deceleration mode as the operation mode, it is also possible to omit this. Conversely, it is also possible to add information to the scan voltage information 92.

[0132] The charged particle beam device D1 according to the present embodiment includes: a charged particle source (in the embodiment, an ion emitter E) that generates charged particles; a plurality of scanning electrodes that generate an electric field for deflecting the charged particles with respect to the charged particles that are emitted by applying an acceleration voltage to the charged particle source and an extraction voltage to an extraction electrode that extracts the charged particles; an electrostatic lens (in the embodiment, an objective lens) that is disposed between the plurality of scanning electrodes and a sample stage, converges the charged particle beam that is scanned by the scanning voltage; and a processing section that acquires measurement conditions (here, an acceleration voltage value Eacc and an operation mode), sets the plurality of scanning voltages respectively based on the acquired measurement conditions.

[0133] With this configuration, in a charged particle beam device that includes an electrostatic lens such as an objective lens OL and two-stage scanning electrodes that are disposed in front of the electrostatic lens, in a case where switching between the acceleration mode and the deceleration mode of the objective lens is performed, a scan image of a sample surface that is distortionless and accurate in size equivalent to before the switching can be obtained. Furthermore, even in a case where the measurement conditions are changed and the position of the main surface of the electrostatic lens is changed, the plurality of scanning voltages can be set respectively based on the changed measurement conditions (here, the operation mode), and thus the trajectory of the ion beam B can be changed. Therefore, the lens effect on the beam after scanning can be reduced.

[0134] (Variation 1 of the First Embodiment)

[0135] The structure of the charged particle beam device of Variation 1 of the First Embodiment can be applied Figure 5 to the charged particle beam device of the First Embodiment. The charged particle beam device of Variation 1 of the First Embodiment differs from the charged particle beam device D1 of the First Embodiment in that a beam booster voltage Vb is applied to the ion beam B. That is, in the structure of the charged particle beam device described with reference to Figure 5 FIG. 6, the alignment electrode 41, the stigmatic correction electrode 42, and the blanking electrode 43 included in the beam booster 4b are not omitted. Furthermore, the alignment power supply 61, the stigmatic correction power supply 62, and the blanking power supply 63 included in the beam booster control section 6 are not omitted. The beam booster power supply section 7 is not omitted. However, the charged particle beam device of Variation 1 of the First Embodiment does not perform the change of the operation mode. The charged particle beam device of Variation 1 of the First Embodiment includes the control section 9a instead of the control section 9.

[0136] The structure of the control section 9a will be described in detail.

[0137] Figure 11 is a diagram that shows an example of the structure of the control section in the charged particle beam device of Variation 1 of the present embodiment. The control section 9a includes a processing section 90a and a storage section 91a. The scanning voltage information 92a and the beam booster voltage information 93a are stored in the storage section 91a.

[0138] Based on the acceleration voltage value Eacc supplied from PC17 and the beam intensifier voltage information 93a read from storage unit 91a, processing unit 90a derives the value of beam intensifier voltage Vb, i.e., beam intensifier voltage value Eb. Processing unit 90a supplies the calculated beam intensifier voltage value Eb to beam intensifier power supply unit 7.

[0139] Based on the accelerating voltage value Eacc supplied from PC17 and the derived beam intensifier voltage value Eb, processing unit 90a derives the value of the first voltage VdefU (i.e., the first voltage value EdefU) and the value of the second voltage VdefL (i.e., the second voltage value EdefL). Processing unit 90a outputs the derived first voltage value EdefU and second voltage value EdefL to MCU 60.

[0140] The scanning voltage information 92a is a tabular information that associates the acceleration voltage value Eacc, the beam intensifier voltage value Eb, information representing the ratio of the first voltage value EdefU to the second voltage value EdefL, and the first voltage value EdefU.

[0141] Figure 12 This is a diagram illustrating an example of scanning voltage information. In Figure 12 In the example shown, the scan voltage information 92a, in addition to the acceleration voltage value Eacc [kV], the beam intensifier voltage value Eb [kV], information indicating the ratio of the first voltage value EdefU to the second voltage value EdefL, and the first voltage value EdefU [V], also associates information indicating the operating mode with information indicating the position of the master plane. Here, the position of the master plane is its position on the Z-axis. Figure 12 As shown, in the scanning voltage information 92a, the acceleration voltage value "30kV", the operation mode "deceleration mode", the beam intensifier voltage value "0V", the position of the main surface "-24.6mm", the ratio of the first voltage to the second voltage "1:0.942", and the first voltage "228V" are associated. Furthermore, in the scanning voltage information 92a, the acceleration voltage value "1kV", the operation mode "acceleration mode", the beam intensifier voltage value "-5V", the position of the main surface "-29.0mm", the ratio of the first voltage to the second voltage "1:0.986", and the first voltage "35.5V" are associated. Furthermore, in the scanning voltage information 92a, the acceleration voltage value "5kV", the operation mode "acceleration mode", the beam intensifier voltage value "-5V", the position of the main surface "-23.7mm", the ratio of the first voltage to the second voltage "1:0.937", and the first voltage "80V" are associated. Figure 12 In this case, the position of the main surface in the information contained in the scanning voltage information 92a can also be omitted.

[0142] The beam booster voltage information 93a is set for each acceleration voltage value Eacc. In the case of a composite charged particle beam device composed of a convergent ion beam and an electron beam, the booster voltage value is limited for each acceleration voltage in order to focus the beam at the intersection (superimposition point) of the two beams (convergent ion beam and electron beam). Figure 13 An example is shown. Figure 13 The relationship between the acceleration voltage value [kV] and the booster voltage value [kV] is shown. As the acceleration voltage becomes lower, the booster voltage value also becomes smaller. However, there is no such limitation in the case of a single-beam device.

[0143] The processing section 90a changes the beam booster voltage value Eb to a voltage value that is lower than or equal to the beam booster voltage setting value TEb shown in the beam booster voltage information 93a in the case where the acceleration voltage value Eacc of the acceleration voltage Vacc is switched. The upper limit of the beam booster voltage Vb is stored in the beam booster voltage information 93a. The processing section 90a can also store the acceleration voltage value Eacc in association with the set beam booster voltage value Eb in the beam booster voltage information 93a after the beam booster voltage value Eb is set. The processing section 90a can also derive the beam booster voltage value Eb based on the beam booster voltage value Eb stored in association with the acceleration voltage value Eacc when the beam booster voltage Vb is set next time.

[0144] Next, the trajectory of the ion beam B is described.

[0145] Figure 14 is a diagram showing an example of the trajectory of the ion beam. In Figure 14 , the X-axis and the Z-axis are as shown in Figure 8 . The acceleration voltage value Eacc is 5 kV and the beam booster voltage value Eb is 5 kV in Figure 14 . Since the beam booster voltage value Eb is 5 kV, the acceleration energy of the ion beam in the booster tube is 10 keV. The scan voltage is set to twice the value when the beam booster voltage is 0 [V]. Here, as an example, the 1st scan voltage value EdefU = 70 [V] and the 2nd scan voltage value EdefL = 66.71. In this case, the 1st scan voltage value EdefU : the 2nd scan voltage value EdefL = 1 : 0.953. This ratio gives the trajectory of the ion beam B that can be regarded as passing through the main surface of the objective lens when the beam booster voltage is 0 [V].

[0146] In Figure 14 , as in Figure 9 , the trajectory of the ion beam B from the 1st scan electrode to the surface of the sample and the result of applying a regression straight line to the trajectory of the ion beam B are shown.

[0147] According to the left figure of 14, the trajectory of ion beam B is inconsistent on the image plane with the result of applying the regression line to the trajectory of ion beam B. This is considered to be due to the lensing effect of the ion beam B in the electric field of the objective lens, thus causing it to deviate from the straight trajectory. A beam passing through the principal plane on the optical axis of the lens travels in a straight line, but in this case, because it deviates from the straight trajectory, it is considered that ion beam B did not pass through the principal plane of the objective lens. This indicates that the position of the principal plane shifts when the beam intensifier voltage Vb is changed.

[0148] Figure 14 The right figure shows in Figure 14 The left image shows a magnified view of the trajectory of ion beam B, where the regression line is applied to the trajectory of ion beam B, resulting in a Z=0 [mm] plot. According to... Figure 16 In the right figure, the trajectory of ion beam B at the sample surface Z = 0 [mm] becomes X = 0.45 mm. That is, the swing of the ion beam B trajectory in the X-axis direction is smaller than 0.5 [mm]. This is presumably due to the swing caused by the lens effect. That is, in this case, it is shown that the scanning width is reduced by 10% due to the lens effect, and even if the size of the scanned image is measured, its value is inaccurate.

[0149] In a variation of this embodiment, in order to reduce the effect of lens action caused by the positional shift of the main surface due to the change in the intensifier voltage Vb, the scanning voltage value Edef is adjusted.

[0150] Figure 15 This is a diagram illustrating an example of the trajectory of an ion beam. Figure 15 In the middle, the X-axis and Z-axis are as follows Figure 8 As shown. In Figure 15 The diagram shows the case where the operating mode is acceleration mode, the acceleration voltage value Eacc is 5kV, and the beam intensifier voltage value Eb is 5kV. Here, as an example, let the first scan voltage value EdefU = 80V and the second scan voltage value EdefL = 74.94. In this case, the ratio of the first scan voltage value EdefU to the second scan voltage value EdefL is 1:0.937.

[0151] exist Figure 15 In, with Figure 9 Similarly, before and after adjusting the scanning voltage value Edef, the trajectory of the ion beam B from the first scanning electrode incident to reaching the sample surface is shown, along with the result of applying the regression line to the trajectory of the ion beam B.

[0152] according to Figure 15 As shown in the left figure, the trajectory of ion beam B and the result of applying the regression line to the trajectory of ion beam B intersect on the image plane. That is, the trajectory of ion beam B can be approximated by a straight line and is considered not to participate in the lensing effect; therefore, it can be regarded as passing through the principal plane.

[0153] Figure 15 The right figure shows in Figure 15 The left image shows the results obtained by comparing the principal plane before and after adjusting the scanning voltage value Edef. Before adjustment, the scanning voltage value Edef was Z = -26.4 [mm], while after adjustment, it was Z = -23.7 [mm]. That is, by applying an intensifier voltage value of 5 [kV], compared with the case without applying an intensifier voltage Vb, it can be seen that the principal plane shifted by approximately 2.7 [mm]. Based on the above, the principal plane shifts when the intensifier voltage Vb is changed. Therefore, it is known that it is necessary to adjust the ratio of the first scanning voltage value EdefU to the second scanning voltage value EdeU, and the magnitude of the first scanning voltage value EdefU to the second scanning voltage value EdefL.

[0154] Figure 15 The right figure shows in Figure 15 The left image shows a magnified view of the result of applying the regression line to the trajectory of ion beam B, resulting in Z = 0 [mm]. According to... Figure 15 As shown in the right figure, after adjusting the scanning voltage value Edef, at X = 0.5 mm, it becomes Z = 0 [mm].

[0155] Based on the above, export Figure 12 The scan voltage information shown is 92a.

[0156] Next, regarding the operation of the charged particle beam device, the process of setting the beam intensifier voltage value Eb, the first voltage value EdefU, and the second voltage value EdefL will be explained.

[0157] Figure 16 This is a flowchart illustrating an example of the operation of the charged particle beam device of Modification 1 of the first embodiment.

[0158] (Step S11)

[0159] In the charged particle beam device D1, the processing unit 90a obtains the accelerating voltage value Eacc from the PC17.

[0160] (Step S12)

[0161] In the charged particle beam device D1, the processing unit 90a reads the beam enhancer voltage information 93a from the storage unit 91a. The processing unit 90a obtains the beam enhancer voltage value Eb associated with the obtained acceleration voltage value Eacc from the read beam enhancer voltage information 93a.

[0162] (Step S13)

[0163] In the charged particle beam device D1, the processing section 90a reads out the scan voltage information 92a from the storage section 91a. The processing section 90a acquires the ratio of the first voltage value to the second voltage value and the first voltage value associated with the combination of the acceleration voltage value Eacc and the acquired beam booster voltage value Eb from the read-out scan voltage information 92a.

[0164] (Step S14)

[0165] In the charged particle beam device D1, the processing section 90a derives the second voltage value on the basis of the acquired ratio of the first voltage value to the second voltage value and the first voltage value.

[0166] (Step S15)

[0167] In the charged particle beam device D1, the processing section 90a sets the first voltage value and the derived second voltage value to the MCU 60. It is to be noted here that the polarity of the first voltage value and the second voltage value needs to be reversed.

[0168] Further, the first voltage value is a value for imparting a specific scan width on the sample, for example, a value for performing a scan of 0.5 mm. In addition, when the polarity of the first voltage value and the second voltage value is reversed, a scan is performed in the opposite direction.

[0169] After the first voltage value and the second voltage value are set to the MCU 60 in (Step S15), the first voltage value and the second voltage value are changed on the basis of the ratio of the first voltage value to the second voltage value, whereby it is possible to change to an arbitrary scan range. Since the first voltage value and the second voltage value are changed on the basis of the ratio of the first voltage value to the second voltage value, it is possible to obtain an accurate scan image without distortion.

[0170] The charged particle beam device D1 according to the modified example 1 of the present embodiment has a charged particle source (in the embodiment, an ion emitter E) that generates charged particles, a plurality of scan electrodes that generate an electric field for deflecting the charged particles to the charged particles emitted by applying an acceleration voltage to the charged particle source and an extraction voltage to an extraction electrode that extracts the charged particles, an electrostatic lens (in the embodiment, an objective lens) that is arranged between the plurality of scan electrodes and a sample stage and converges the charged particle beam scanned by a scan voltage, and a processing section that acquires measurement conditions (here, an acceleration voltage value Eacc and a booster voltage value Eb), sets a plurality of scan voltages respectively on the basis of the acquired measurement conditions and information that determines the position of a main surface of the electrostatic lens.

[0171] By so constituting, in the charged particle beam device provided with the electrostatic lens such as the objective lens OL and the two-stage scanning electrodes provided at the front stage of the electrostatic lens, in the case where the applied voltage of the booster electrode constituting the objective lens is changed, a scan image of the sample surface of the same size and without distortion as before the change can be obtained. Further, even in the case where the measurement condition (here, the booster voltage value Eb) is changed and the position of the main surface of the electrostatic lens is changed, a plurality of scanning voltages can be set based on the changed measurement condition, respectively, and thus the orbit of the ion beam B can be changed. Therefore, the lens action received by the beam after scanning can be reduced.

[0172] (Second Modification of the First Embodiment)

[0173] The structure of the charged particle beam device of the second modification of the first embodiment can be applied Figure 5 . The charged particle beam device of the second modification of the first embodiment differs from the charged particle beam device D of the first embodiment in that the booster voltage Vb is applied to the ion beam B. That is, in the structure of the charged particle beam device described with reference to Figure 5 , the alignment electrode 41, the stigmator electrode 42, and the blanking electrode 43 included in the booster 4b are not omitted. Further, the alignment power supply 61, the stigmator power supply 62, and the blanking power supply 63 included in the booster control section 6 are not omitted. The booster power supply section 7 is not omitted. The charged particle beam device of the second modification of the first embodiment is provided with the control section 9b instead of the control section 9.

[0174] The structure of the control section 9b will be described in detail.

[0175] Figure 17 is a view showing an example of the structure of the control section 9b in the charged particle beam device of the second modification of the embodiment. The control section 9b is provided with a processing section 90b and a storage section 91b. The scanning voltage information 92b and the booster voltage information 93b are stored in the storage section 91b.

[0176] The processing section 90b derives the value of the booster voltage Vb, i.e., the booster voltage value Eb, based on the acceleration voltage value Eacc supplied from the PC 17 and the booster voltage information 93b read out from the storage section 91a. The processing section 90b supplies the calculated booster voltage value Eb to the booster power supply section 7.

[0177] The processing section 90b derives the value of the first voltage VdefU, i.e., the first voltage value EdefU, and the value of the second voltage defL, i.e., the second voltage value EdefL, based on the acceleration voltage value Eacc supplied from the PC 17, the information indicating the operation mode, and the derived beam booster voltage value Eb. The processing section 90b outputs the derived first voltage value EdefU and the second voltage value EdefL to the MCU 60.

[0178] The scan voltage information 92b is table-form information in which the acceleration voltage value Eacc, the information indicating the operation mode, the beam booster voltage value Eb, the information indicating the ratio of the first voltage value EdefU to the second voltage value EdefL, and the first voltage value EdefU are associated with each other.

[0179] An example of the scan voltage information 92b can apply the scan voltage information 92a, and an example of the beam booster voltage information 93b can apply the beam booster voltage information 93a.

[0180] Next, the processing of setting the beam booster voltage value Eb, the first voltage value EdefU, and the second voltage value EdefL will be described with respect to the operation of the charged particle beam device.

[0181] Figure 18 is a flowchart showing an example of the operation of the charged particle beam device of the modified example 2 of the first embodiment.

[0182] (Step S21)

[0183] In the charged particle beam device D1, the processing section 90b acquires the acceleration voltage value Eacc and the information indicating the operation mode from the PC 17.

[0184] (Step S22)

[0185] In the charged particle beam device D1, the processing section 90b reads out the beam booster voltage information 93b from the storage section 91b. The processing section 90b acquires the beam booster voltage value Eb associated with the acquired acceleration voltage value Eacc from the read beam booster voltage information 93b.

[0186] (Step S23)

[0187] In the charged particle beam device D1, the processing section 90b reads out the scan voltage information 92b from the storage section 91b. The processing section 90b acquires the ratio of the first voltage value to the second voltage value and the first voltage value associated with the combination of the acceleration voltage value Eacc, the information indicating the operation mode, and the acquired beam booster voltage value Eb from the read scan voltage information 92b.

[0188] (Step S24)

[0189] In the charged particle beam device D1, the processing section 90b derives the second voltage value based on the ratio of the first voltage value to the second voltage value and the first voltage value.

[0190] (Step S25)

[0191] In the charged particle beam device D1, the processing section 90b sets the first voltage value and the derived second voltage value to the MCU 60. It should be noted here that the polarity of the first voltage value and the second voltage value needs to be reversed.

[0192] Further, the first voltage value is a value for a specific scan width to be imparted on the sample, for example, a value for a scan of 0.5 mm. In addition, when the polarity of the first voltage value and the second voltage value is reversed, scanning is performed in the opposite direction.

[0193] After the first voltage value and the second voltage value are set to the MCU 60 in (step S25), the first voltage value and the second voltage value are changed based on the ratio of the first voltage value to the second voltage value, whereby it is possible to change to an arbitrary scan range. Since the first voltage value and the second voltage value are changed based on the ratio of the first voltage value to the second voltage value, an accurate scan image without distortion can be obtained.

[0194] The charged particle beam device D1 according to the modified example 2 of the present embodiment is provided with: a charged particle source (in the embodiment, an ion emitter E) that generates charged particles; a plurality of scanning electrodes that generate an electric field for deflecting the charged particles on the charged particles that are emitted by applying an acceleration voltage to the charged particle source and an extraction voltage to an extraction electrode that extracts the charged particles; an electrostatic lens (in the embodiment, an objective lens) that is arranged between the plurality of scanning electrodes and a sample stage, converges the charged particle beam after scanning by a scanning voltage; and a processing section that acquires measurement conditions (here, an acceleration voltage value Eacc, an enhancer voltage value Eb, and information indicating a mode of operation), sets a plurality of scanning voltages based on the acquired measurement conditions and information that determines the position of the main surface of the electrostatic lens, respectively.

[0195] With such a configuration, in a charged particle beam device provided with an electrostatic lens such as an objective lens OL and a two-stage scanning electrode provided in front of the electrostatic lens, in a case where switching between acceleration mode and deceleration mode of the objective lens or changing of the applied voltage of the booster electrode configuring the objective lens is performed, a scan image of a sample surface of the same size and without distortion as before the switching or changing can be obtained. Further, even in a case where the measurement conditions (here, the acceleration voltage value Eacc, the booster voltage value Eb, and information indicating the operation mode) are changed and the positions of the main surfaces of the electrostatic lenses are changed, a plurality of scanning voltages can be set based on the changed measurement conditions, respectively, and thus the trajectory of the ion beam B can be changed. Therefore, the lens action on the beam after scanning can be reduced.

[0196] (Second Embodiment)

[0197] The composite charged particle beam device D of the second embodiment is provided with a scanning electron microscope D2 (not shown) such as an electron beam column on the basis of the charged particle beam device D1 described above. However, the alignment electrode 41, the stigmator electrode 42, and the blanking electrode 43 included in the beam booster 4b are not omitted. Further, the alignment power supply 61, the stigmator power supply 62, and the blanking power supply 63 included in the beam booster control section 6 are not omitted. The beam booster power supply section 7 is not omitted. Figure 5

[0198] The scanning electron microscope D2 detects secondary electrons and reflection electrons emitted from the sample SP1 by irradiating an electron beam toward the sample SP1, and thereby observes the surface and cross section of the sample SP1.

[0199] The composite charged particle beam device D of the second embodiment irradiates an electron beam and a convergent ion beam toward the same point on a sample. In order to irradiate the electron beam and the convergent ion beam toward the same point on the sample, it is required that the focal point of the electron beam and the focal point of the convergent ion beam are aligned with the same point (irradiation point) on the sample. The same point on the sample irradiated with the electron beam and the convergent ion beam is referred to as a coincidence point (CP).

[0200] The composite charged particle beam device of the second embodiment is provided with a control section 9c instead of the control section 9.

[0201] The structure of the control section 9c is described in detail.

[0202] Figure 19 Fig. 9 is a diagram showing an example of the structure of the control section 9c in the composite charged particle beam device of the second embodiment. The control section 9c is provided with a processing section 90c and a storage section 91c. The scanning voltage information 92c and the beam booster voltage information 93c are stored in the storage section 91c.

[0203] ​The processing section 90c derives the value of the beam booster voltage Vb, i.e., the beam booster voltage value Eb, based on the acceleration voltage value Eacc supplied from the PC 17 and the beam booster voltage information 93c read out from the storage section 91a. The processing section 90c supplies the calculated beam booster voltage value Eb to the beam booster power supply section 7.

[0204] The processing section 90c derives the value of the 1st voltage VdefU, i.e., the 1st voltage value EdefU, and the value of the 2nd voltage VdefL, i.e., the 2nd voltage value EdefL, based on the acceleration voltage value Eacc supplied from the PC 17 and the derived beam booster voltage value Eb. The processing section 90c outputs the derived 1st voltage value EdefU and the 2nd voltage value EdefL to the MCU 60.

[0205] The scan voltage information 92c is table-form information in which the acceleration voltage value Eacc, the beam booster voltage value Eb, information indicating the ratio of the 1st voltage value EdefU to the 2nd voltage value EdefL, and the 1st voltage value EdefU are associated with each other.

[0206] An example of the scan voltage information 92c can be applied to the scan voltage information 92a described with reference to Figure 12 the scan voltage information 92a.

[0207] The beam booster voltage information 93c is table-form information in which the acceleration voltage value Eacc and the beam booster voltage setting value TEb calculated in advance in accordance with the desired focal length are associated with each other. The beam booster voltage setting value TEb is a voltage value at which the electron beam and the convergent ion beam can be focused on the same point CP on the sample SPl in the case where the acceleration voltage value Eacc is applied. In the compound charged particle beam device D, the beam booster voltage setting value TEb is set based on the beam booster voltage information 93c, whereby the ion beam B and the electron beam are irradiated on the same point on the sample SPl.

[0208] Figure 13 The range of the beam booster voltage Vb that can be focused is shown, and thus the description thereof is omitted here.

[0209] The compound charged particle beam device D according to the 2nd embodiment can derive the beam booster voltage value Eb based on the acceleration voltage value Eacc, the focal length of the charged particle beam converged by the objective lens, and the focal length of the electron beam irradiated by the electron beam irradiation section of the irradiation electron beam, and thus can focus the charged particle beam on the CP. That is, the value of the beam booster voltage Vb of the booster tube 4a that can focus the convergent ion beam on the CP (the beam booster voltage value Eb) can be set in accordance with the acceleration voltage applied to the charged particle beam (the ion beam B).

[0210] The charged particle beam device D1, a part of the compound charged particle beam device D, such as the control section 9 (9, 9a, 9b, 9c) in the above-described embodiments can also be realized by a computer. In this case, it can also be realized by recording a program for realizing the control function in a recording medium readable by a computer, causing a computer system to read in and execute the program recorded in the recording medium. Further, the "computer system" referred to here is a computer system built into the charged particle beam device D1, the compound charged particle beam device D, including an OS or a hardware such as a peripheral device. Further, the "recording medium readable by a computer" refers to a portable medium such as a floppy disk, an optical magnetic disk, a ROM, a CD-ROM, a storage device such as a hard disk built into a computer system. Further, the "recording medium readable by a computer" can also include a recording medium that dynamically holds a program for a short time, such as a communication line in the case where a program is transmitted via a network such as the Internet or a telephone line, a volatile memory inside a computer system that becomes a server or a client in this case, that holds a program for a certain time. Further, the above-described program can be a program for realizing a part of the above-described function, and can also be a program that can realize the above-described function by being combined with a program already recorded in a computer system.

[0211] Further, a part or all of the control section 9 in the above-described embodiments can also be realized in the form of an integrated circuit such as an LSI (Large Scale Integration). Each functional block of the control section 9 can individually become a processor, or a part or all can be integrated to become a processor. Further, the method of integration is not limited to an LSI, and can also be realized by a dedicated circuit or a general-purpose processor. Further, in the case where a technology replacing the integration of an LSI appears due to advances in semiconductor technology, an integrated circuit based on this technology can also be used.

[0212] The embodiment of the present application has been described in detail with reference to the drawings, but the specific configuration is not limited to the above-described configuration, and various design changes or the like can be made within the scope of the gist of the present application.

Claims

1. A charged particle beam device, wherein the charged particle beam device is provided with: a charged particle source that generates charged particles; a plurality of scanning electrodes that generate an electric field for deflecting the charged particles, which are emitted by applying an acceleration voltage to the charged particle source and an extraction voltage to an extraction electrode that extracts the charged particles, for obtaining a scan image of a distortion-free, dimensionally accurate sample surface; an electrostatic lens that is arranged between the plurality of scanning electrodes and a sample stage, converges the charged particle beam that has been deflected by the scanning electrodes; and a processing section that acquires a measurement condition, sets a scanning voltage to be applied to the plurality of scanning electrodes on the basis of the acquired measurement condition, the processing section acquires information on a plurality of determined scanning voltages that conform to the measurement condition from scanning voltage information in which a plurality of measurement conditions are associated with information on a plurality of scanning voltages determined by the plurality of scanning electrodes for the plurality of measurement conditions, sets the plurality of scanning voltages on the basis of the acquired information on the plurality of determined scanning voltages, the plurality of scanning voltages applied to the plurality of scanning electrodes included in the scanning voltage information have a prescribed ratio for each of the plurality of measurement conditions.

2. The charged particle beam device according to claim 1, wherein the plurality of scanning electrodes include: a first scanning electrode that applies a first scanning voltage to the charged particle beam; and a second scanning electrode that is arranged between the first scanning electrode and the sample stage, applies a second scanning voltage to the charged particle beam.

3. The charged particle beam device according to claim 1 or 2, wherein the measurement condition includes information on a determined acceleration voltage and information on a determined operation mode.

4. The charged particle beam device according to claim 1 or 2, wherein the charged particle beam device is provided with a beam booster voltage application section that is arranged between the charged particle source and the sample stage, applies a beam booster voltage to the charged particle beam, the measurement condition includes information on a determined acceleration voltage and information on a determined beam booster voltage.

5. The charged particle beam device according to claim 4, wherein the processing section acquires information on a determined beam booster voltage that conforms to the acquired measurement condition from beam booster voltage information in which a measurement condition is associated with information on a beam booster voltage determined by the beam booster voltage application section, sets the beam booster voltage on the basis of the acquired information on the determined beam booster voltage.

6. A composite charged particle beam device that is a composite charged particle beam device in which an electron beam barrel is further mounted in the charged particle beam device according to claim 4, wherein the processing section sets the beam booster voltage on the basis of the acceleration voltage, a focal length of the charged particle beam that is converged by the electrostatic lens, and an irradiation point of an electron beam that is irradiated by an electron beam irradiation section.

7. The composite charged particle beam device according to claim 6, wherein ​ A focal point of the charged particle beam converged by the electrostatic lens coincides with an irradiation point of the electron beam.

8. The compound charged particle beam device according to claim 6 or 7, wherein The processing section acquires information of a determined beam booster voltage that conforms to the acquired measurement condition from beam booster voltage information in which measurement conditions are associated with information of a beam booster voltage determined by the beam booster voltage application section, and sets the beam booster voltage based on the information of the determined beam booster voltage acquired.

9. A control method of a charged particle beam device, wherein The control method of the charged particle beam device has the steps of: applying an acceleration voltage to a charged particle source and an extraction voltage to an extraction electrode that extracts charged particles, whereby the charged particle source emits charged particles; acquiring a measurement condition, and setting a plurality of scan voltages applied to a plurality of scan electrodes that generate an electric field for deflecting the charged particles and obtaining a scan image of a distortionless, dimensionally accurate sample surface based on the acquired measurement condition; applying a scan voltage to the plurality of scan electrodes based on each of the plurality of scan voltages set; an electrostatic lens disposed between the plurality of scan electrodes and a sample stage converges the charged particles deflected by the scan voltage, in the step of setting, a plurality of pieces of information of determined scan voltages that conform to the measurement conditions are acquired from scan voltage information in which a plurality of measurement conditions are associated with information of scan voltages determined by the plurality of scan electrodes applied respectively for the plurality of measurement conditions, and the plurality of scan voltages are set respectively based on the information of the determined plurality of scan voltages acquired, the plurality of scan voltages applied respectively to the plurality of scan electrodes included in the scan voltage information have a prescribed ratio for each of the plurality of measurement conditions.

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