Charged particle beam device

Abstract

A charged particle beam device is provided with: an electric field suppression electrode (109) having an opening through which a charged particle beam (102) passes in a charged particle optical system; and a multipole electrode (108) that has an opening through which the charged particle beam passes between the main surface (107) of the objective lens and the electric field suppression electrode (109), and that generates an electrostatic deflection field or an electrostatic electrode field on the charged particle beam, the charged particle beam device being provided with: a boost voltage source (112) that applies a boost voltage to the upper magnetic path (105) of the objective lens (103); a deceleration voltage source (114) that applies a deceleration voltage to the sample (110), the lower magnetic circuit (106) of the objective lens (103), and the electric field suppression electrode; and a correction voltage source (113) that causes the multipole electrode to generate an electrostatic deflection field or an electrostatic multipole field.

Description

Technical Field

[0001] The present invention relates to a charged particle beam device. Background Art

[0002] In the semiconductor device manufacturing process, pattern dimension measurement and management are crucial for improving yield. Scanning electron microscopes, a type of charged particle beam device, are widely used for pattern dimension measurement. To accurately measure the pattern dimensions of increasingly miniaturized semiconductor devices using scanning electron microscopes, higher resolution is required. However, to minimize electron beam damage to devices, both lower acceleration voltage and higher resolution are necessary.

[0003] When performing high-resolution observation at low accelerating voltages, the deceleration method and the boost method are used to reduce aberrations generated in the objective lens. The deceleration method applies a voltage (deceleration voltage) of the same polarity as the charge of the irradiating charged particle beam to the specimen, thereby decelerating the irradiating charged particle beam before it reaches the specimen. The boost method applies a voltage (boost voltage) of the opposite polarity to the charge of the irradiating electron beam to the objective lens, thereby accelerating the irradiating charged particles as they pass through the objective lens.

[0004] The combination of the deceleration method and the boost method is useful for achieving both low acceleration and high resolution. However, the potential difference between the deceleration voltage and the boost voltage creates an electric field, and the force generated by this electric field can cause conductive foreign matter around the specimen or the objective lens to fly away. If foreign matter adheres to the circuits of semiconductor devices, it can cause device malfunction. Therefore, stricter foreign matter control is required, especially in advanced semiconductor processes where the minimum size of circuit patterns is approaching nanometers.

[0005] To reduce the risk of foreign matter scattering, it is necessary to suppress the electric field on the sample. For example, Patent Document 1 describes a charged particle beam device in which an electrode (third electrode 166 ) having the same potential as the sample is provided below the objective lens.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-220241 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] In a charged particle beam device, in order to achieve both low acceleration and high resolution and reduced risk of foreign matter scattering, as shown in Patent Document 1, an electrode with the same potential as the sample (hereinafter referred to as an electric field suppression electrode) is arranged directly above the sample, so that a low electric field is applied to the sample, thereby suppressing the scattering of foreign matter.

[0011] In the embodiment of the present invention, the electric field suppression electrode is used for the optical microscope, and the optical microscope is used for the optical microscope.Yet, when the electric field suppression electrode is set, it is impossible to avoid the axis deviation on the mechanism of the assembling of the electric field suppression electrode, and the deviation (mechanical error) of the spatial resolution of each device may increase.Specifically, along with the axis deviation of the electric field suppression electrode, the central axis of the object lens becomes inconsistent with the central axis of the electric field suppression electrode, thereby the electric field in the object lens is deformed, and produces an electrostatic deflection field.The effect of this electrostatic deflection field is to deflect the charged particle beam in the object lens, and therefore produces the off-axis aberration caused by the object lens with respect to the charged particle beam.If the off-axis aberration of the object lens becomes the size that cannot be ignored with respect to the Airy disk caused by on-axis aberration, diffraction, the spot diameter of the charged particle beam is deformed, and spatial resolution deteriorates.

[0012] In semiconductor device dimensional measurement processes using charged particle beam devices, mechanical errors must be minimized. This is because if the mechanical errors of the charged particle beam devices used for dimensional measurement are large, the dimensional measurements from each device cannot be trusted. For example, in state-of-the-art semiconductor processes, where the minimum dimensions of circuit patterns approach nanometers, mechanical errors must be suppressed to sub-nanometer levels for management.

[0013] Furthermore, in Patent Document 1, the electric field reduction effect on the sample is reduced by arranging the control electrode for extracting secondary electrons from the sample on the sample side relative to the electric field suppression electrode.

[0014] Means for solving problems

[0015] As an embodiment of the present invention, a charged particle beam device includes: a sample stage on which a sample is placed; a charged particle optical system including a charged particle beam source; an objective lens having an upper magnetic circuit, a lower magnetic circuit, and a coil for focusing the charged particle beam released from the charged particle beam source on the sample; an electric field suppression electrode, which is arranged between the objective lens and the sample stage and below the main surface of the objective lens, and has an opening for allowing the charged particle beam to pass through; and a multipole electrode, which is arranged between the objective lens and the electric field suppression electrode and below the main surface of the objective lens, and has an opening for allowing the charged particle beam to pass through, and generates an electrostatic deflection field or an electrostatic electrode field for the charged particle beam; a boost voltage source, which applies a boost voltage to the upper magnetic circuit; a deceleration voltage source, which applies a deceleration voltage to the sample, the lower magnetic circuit, and the electric field suppression electrode; and a correction voltage source, which causes the multipole electrode to generate an electrostatic deflection field or an electrostatic multipole field.

[0016] Effects of the Invention

[0017] The present invention provides a charged particle beam device that achieves both reduction of foreign matter and reduction of mechanical errors. Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a diagram showing the structure of a charged particle beam device.

[0019] Figure 2 This is an example of a structure in which the multipolar electrodes are set as electrostatic quadrupole deflection electrodes.

[0020] Figure 3 This is a diagram for explaining the mechanism of canceling the electrostatic deflection field generated by axis offset.

[0021] Figure 4A This is an example of mounting a multipole electrode and an electric field suppression electrode in a charged particle beam device.

[0022] Figure 4B This is an example of mounting a multipole electrode and an electric field suppression electrode in a charged particle beam device.

[0023] Figure 4C This is an example of mounting a multipole electrode and an electric field suppression electrode in a charged particle beam device.

[0024] Figure 4D This is an example of mounting a multipole electrode and an electric field suppression electrode in a charged particle beam device.

[0025] Figure 5 This is an example of a structure in which the multipolar electrodes are set as electrostatic dodecapole deflection electrodes.

[0026] Figure 6A This is an example of a structure in which the multipole electrodes are used as an electrostatic octupole lens.

[0027] Figure 6B This is an example of a structure in which the multipole electrodes are used as an electrostatic octupole lens.

[0028] Figure 6C This is an example of a structure in which the multipole electrodes are used as an electrostatic octupole lens.

[0029] Figure 7A This is an example of a structure in which the multipole electrodes are used as an electrostatic dodecapole lens.

[0030] Figure 7B This is an example of a structure in which the multipole electrodes are used as an electrostatic dodecapole lens.

[0031] Figure 7C This is an example of a structure in which the multipole electrodes are used as an electrostatic dodecapole lens.

[0032] Figure 8 This is an example of a table storing optical conditions of an optical mode.

[0033] Figure 9 This is an example of controlling the correction voltage source. DETAILED DESCRIPTION

[0034] In the present disclosure, a charged particle beam device is proposed, which preferably suppresses the high intensity of the electric field on the sample when using the lifting method and the deceleration method by arranging an electric field suppression electrode directly above the sample, and preferably suppresses the increase of mechanical errors accompanying the optical axis offset of the electric field suppression electrode by arranging a multipole electrode for correcting the electrostatic deflection field caused by the optical axis offset of the electric field suppression electrode directly above the electric field suppression electrode. According to the present disclosure, by suppressing the electrostatic deflection field caused by the axial offset of the electric field suppression electrode and the off-axis aberration caused thereby, and achieving a reduction in the electric field intensity on the sample, both mechanical error reduction and foreign matter reduction are achieved. In addition, there is no need to reassemble the electric field suppression electrode for reducing mechanical errors.

[0035] Figure 1 The charged particle optical system of the charged particle beam device of this embodiment includes an electric field suppression electrode for reducing the electric field on the sample and a multipole electrode for correcting the electrostatic deflection field caused by axial deviation of the electric field suppression electrode.

[0036] A charged particle beam 102 generated by a charged particle source 101 is narrowed by an objective lens 103, passes through a multipole electrode 108 disposed below a primary surface 107 of the objective lens, and an electric field suppression electrode 109 disposed directly below the multipole electrode 108, and then is incident on a sample 110 placed on a sample stage 111. The objective lens 103 includes a coil 104, an upper magnetic circuit 105, and a lower magnetic circuit 106.

[0037] The charged particle beam apparatus also includes a control unit 120, and the charged particle optical system, detection system (not shown), and sample stage 111 included in the charged particle beam apparatus are controlled by the control unit 120. The control unit 120 is, for example, a computer connected to an input device and an output device. The control unit 120 controls the charged particle optical system, detection system, and sample stage 111 in response to user instructions via the input device, visualizes detection results of the detection system, and outputs measurement results of the sample 110 based on the image to the output device.

[0038] A deceleration voltage source 114 applies a deceleration voltage of -20 kV to 0 kV to the lower magnetic circuit 106, the electric field suppression electrode 109, and the sample 110, which is required for high resolution. Furthermore, a boost voltage source 112 applies a boost voltage of 0 kV to 20 kV to the upper magnetic circuit 105, which is required for high resolution. The difference between the boost voltage and the deceleration voltage generates an electric field directed toward the sample 110. However, the electric field suppression electrode 109, which has the same potential as the sample 110, largely shields this electric field from the sample 110.

[0039] However, when the central axes of the upper magnetic circuit 105 and the electric field suppression electrode 109 are inconsistent, that is, when the central axis of the electric field suppression electrode 109 is offset relative to the central axis of the upper magnetic circuit 105, the rotational symmetry of the electrostatic lens field formed by the upper magnetic circuit 105, to which the boost voltage is applied, and the electric field suppression electrode 109, to which the deceleration voltage is applied, is destroyed, generating an electrostatic deflection field 115. The electrostatic deflection field 115 deflects the charged particle beam 102 off-axis of the objective lens, thus becoming a major cause of off-axis aberration of the objective lens. Therefore, in this embodiment, an electrostatic deflection field 116 is generated to offset the electrostatic deflection field 115 by connecting the multipole electrode 108 to a correction voltage source 113. By mutually offsetting the electrostatic deflection field 115 and the electrostatic deflection field 116, the generation of off-axis aberration associated with the axial offset of the electric field suppression electrode 109 can be avoided. Furthermore, the voltage applied by the correction voltage source 113 to the multipolar electrode 108 is between -1 kV and +1 kV relative to the voltage output by the deceleration voltage source 114. In this case, if the axial misalignment of the electric field suppression electrode 109 is approximately between -100 μm and +100 μm, the electrostatic deflection fields cancel each other out. However, the voltage applied by the correction voltage source 113 and the amount of axial misalignment that can be corrected for the electric field suppression electrode 109 are guidelines and may exceed the above-mentioned numerical ranges.

[0040] Figure 2 This is an example of using the multipole electrode 108 as an electrostatic quadrupole deflection electrode 201-204. The electrostatic quadrupole deflection electrode is the most basic multipole electrode capable of generating the electrostatic deflection field 116. The electrodes 201-204 constituting the electrostatic quadrupole deflection electrode all have identical shapes and have openings for passing the charged particle beam. Furthermore, the correction voltage source 113 includes an independently operating x-correction voltage source 211 and a y-correction voltage source 212. By applying a voltage between electrodes 201 and 202 facing each other, as indicated by the x-correction voltage source 211, and between electrodes 203 and 204 facing each other, as indicated by the y-correction voltage source 212, an electrostatic deflection field can be generated in two linearly independent directions (x and y).

[0041] use Figure 3 The following describes the mechanism for canceling out electrostatic deflection field 115 generated by axis offset. If the central axis of electric field suppression electrode 109 deviates from the central axis of upper magnetic circuit 105, the central axis of the electrostatic lens formed by the boost and deceleration voltages shifts, generating electrostatic deflection field 115. Multipole electrode 108 generates electrostatic deflection field 116 of equal magnitude and opposite direction to electrostatic deflection field 115, causing electrostatic deflection field 115 and electrostatic deflection field 116 to cancel each other out.

[0042] Like this, electric field suppression electrode 109 and multipole electrode 108 both sides are configured below the principal surface 107 of object lens. Here, principal surface refers to the reference position at which the charged particle beam incident parallel to the optical axis of object lens begins to converge at the focal point. The reason is as follows. If electric field suppression electrode 109 is configured on the principal surface 107 of object lens or above it, the aberration of charged particle beam significantly increases and spatial resolution decreases. Through deceleration voltage source 114, electric field suppression electrode 109 and sample 110 become equipotential, so in the space between electric field suppression electrode 109 and sample 110, the focusing action of lens is hindered. Therefore, in order not to reduce spatial resolution, electric field suppression electrode 109 originally needs to be configured as close to sample 110 as possible. In addition, preferably sample stage 111 can change height. Thus, no matter how the structure of sample is, the distance between the upper surface of sample 110 and the lower surface of electric field suppression electrode 109 can be kept constant.

[0043] On the other hand, when the multipole electrode 108 is away from the electric field suppression electrode 109 and is arranged on the main surface 107 of the objective lens or above the main surface 107 of the objective lens, the deviation in the overlap between the spatial distribution of the electrostatic deflection field 115 generated by the electric field suppression electrode 109 and the spatial distribution of the electrostatic deflection field 116 generated by the multipole electrode 108 becomes larger, and the electrostatic deflection field 116 cannot be offset by the electrostatic deflection field 115.

[0044] Alternatively, by configuring the electric field suppression electrode 109 itself as a multipolar electrode, it is also possible to counteract the electrostatic deflection field caused by axial misalignment of the electric field suppression electrode 109. However, this approach presents the problem of being unable to shield the electric field in the gaps between the electrodes that constitute the multipolar electrode. Therefore, to suppress the electric field on the sample and to mitigate mechanical errors caused by axial misalignment of the electric field suppression electrode, it is preferable to separately provide a disk-shaped (i.e., annular) electric field suppression electrode and a multipolar electrode having an opening through which the charged particle beam passes.

[0045] The material of multipolar electrode 108 and electric field suppression electrode 109 is a conductive non-magnetic body such as single crystal silicon, molybdenum, and titanium. This is because, under the situation of a magnetic body, the magnetic field distribution in the object lens changes, and there is a problem that spatial resolution reduces. The material of exemplification is a non-insulator and non-magnetic material with high strength and capable of high-precision processing, which is suitable as the material of these electrodes.

[0046] In addition, the above description has been made of the voltage applied to the charged particle optical system during sample observation. However, when changing samples, the outputs of the boost voltage source 112, the correction voltage source 113, and the deceleration voltage source 114 are all set to the same potential (reference potential) as the lens barrel. This is to prevent an electric field from being generated around the objective lens 103 and the sample 110 when changing samples.

[0047] use Figures 4A to 4D, illustrating how the multipole electrode 108 and the electric field suppression electrode 109 are mounted on a charged particle beam device. A solid insulating material 401 is sandwiched between the multipole electrode 108 and the electric field suppression electrode 109. The solid insulating material 401 supports the multipole electrode 108, which is positioned directly above the electric field suppression electrode 109, and prevents electrical short circuits between the multipole electrode 108 and the electric field suppression electrode 109. In this example, the planar shapes of the multipole electrode 108, the electric field suppression electrode 109, and the solid insulating material 401 are all annular.

[0048] The solid insulating material 401 is made of an inorganic dielectric such as silicon dioxide, aluminum oxide, talc, sapphire, or zirconium dioxide. If the solid insulating material 401 is made of an organic dielectric, the generation of hydrocarbon gas may reduce the vacuum level in the device.

[0049] (First Configuration Example)

[0050] Figure 4A The first structural example is shown. To prevent the charged particle beam 102 from contacting the solid insulating material 401, the inner diameter of the solid insulating material 401 is made larger than the inner diameters of the multipole electrode 108 and the electric field suppression electrode 109. When the charged particle beam 102 contacts the solid insulating material 401, the contact portion becomes charged, affecting the behavior of the charged particle beam. Therefore, contact between the charged particle beam 102 and the solid insulating material 401 should be prevented. If the inner diameter of the solid insulating material 401 is less than or equal to the inner diameter of the multipole electrode 108 or the inner diameter of the electric field suppression electrode 109, the charged particle beam 102 may contact the solid insulating material 401, potentially charging the solid insulating material 401. This charging of the solid insulating material 401 is a major factor contributing to increased mechanical errors.

[0051] (Second Configuration Example)

[0052] Figure 4B The second structural example is shown. To reduce the electric field at triple point 402, where solid insulating material 401, multipolar electrode 108, and vacuum contact are located, a protrusion is provided on the surface of multipolar electrode 108 that faces electric field suppression electrode 109, in the solid insulating material-side region of the triple point. In other words, at the point where solid insulating material 401 and multipolar electrode 108 are in contact, a portion of multipolar electrode 108 protrudes toward solid insulating material 401. Similarly, to reduce the electric field at triple point 403, where solid insulating material 401, electric field suppression electrode 109, and vacuum contact are located, a protrusion is provided on the surface of electric field suppression electrode 109 that faces multipolar electrode 108, in the solid insulating material-side region of the triple point. In other words, at the point where solid insulating material 401 and electric field suppression electrode 109 are in contact, a portion of electric field suppression electrode 109 protrudes toward solid insulating material 401.

[0053] (Third Configuration Example)

[0054] Figure 4C The third structural example is shown. To reduce the electric field at triple point 402, where solid insulating material 401, multipolar electrode 108, and vacuum contact are located, a protrusion is provided on the surface of multipolar electrode 108 that faces electric field suppression electrode 109, in the vacuum-side region of the triple point. In other words, in the portion where solid insulating material 401 and multipolar electrode 108 are not in contact, a portion of multipolar electrode 108 protrudes toward the vacuum side. Similarly, to reduce the electric field at triple point 403, where solid insulating material 401, electric field suppression electrode 109, and vacuum contact are located, a protrusion is provided on the surface of electric field suppression electrode 109 that faces multipolar electrode 108, in the vacuum-side region of the triple point. In other words, in the portion where solid insulating material 401 and electric field suppression electrode 109 are not in contact, a portion of electric field suppression electrode 109 protrudes toward the vacuum side.

[0055] (Fourth Configuration Example)

[0056] Figure 4D The fourth configuration example is equivalent to a structure obtained by combining the second configuration example and the third configuration example.

[0057] As in the second to third structural examples, the structure of reducing the electric field intensity at the triple point where two dielectrics and the electrode come into contact has the advantage of preventing creeping discharge in the solid insulating material 401 .

[0058] A modified example of the method of correcting the axial offset using the electric field suppression electrode 109 of the multipolar electrode 108 will be described below.

[0059] (Variation 1)

[0060] exist Figure 2 , an example is shown in which the electrostatic deflection field 116 is generated by the electrostatic quadrupole deflection electrodes 201 to 204 to cancel the electrostatic deflection field 115 generated by the axis deviation of the electric field suppression electrode 109. Figure 2 In the case of the electrostatic quadrupole deflection electrodes 201 to 204 shown, an electrostatic sextupole field is generated together with the electrostatic deflection field 116. The electrostatic sextupole field is a major cause of tertiary astigmatism and coma, and thus may increase mechanical errors.

[0061] Figure 5An example of electrostatic dodecapole deflection electrodes 501 to 512 capable of preventing the generation of an electrostatic sextupole field associated with the generation of an electrostatic deflection field 116 is shown. The electrodes have a non-uniform angular distribution. The x-correction voltage source 211 applies a voltage between the opposing electrode groups (510, 508, 512) and the electrode groups (504, 502, 506), while the y-correction voltage source 212 applies a voltage between the opposing electrode groups (501, 503, 511) and the electrode groups (507, 509, 505). This generates electrostatic deflection fields in two linearly independent directions (x and y).

[0062] Figure 2 、 Figure 5 The example of the structure of the multipole electrode 108 is an example in which the multipole electrode 108 generates an electrostatic deflection field. However, by configuring the correction voltage source 113 so that each electrode (pole) is connected to a voltage source, the multipole electrode 108 can be made into a multipole lens that generates an electrostatic field and an electrostatic multipole field. An example of this is shown below.

[0063] (Variation 2)

[0064] Figures 6A to 6C This figure shows an embodiment in which the multipole electrode 108 is configured as an electrostatic octupole lens 601-608. The poles 601-608 that make up the electrostatic octupole lens all have the same shape, and are capable of generating an electrostatic quadrupole field in addition to the electrostatic deflection field. Therefore, in addition to the electrostatic deflection field generated by the axial offset of the electric field suppression electrode 109, the electrostatic quadrupole field can also be corrected.

[0065] When generating an electrostatic deflection field, such as Figure 6B As shown, when an electrostatic quadrupole field is generated, Figure 6C As shown, the voltage applied to each pole is controlled. By superimposing the voltages applied to each pole, an electrostatic deflection field and an electrostatic quadrupole field can be superimposed and generated.

[0066] (Variation 3)

[0067] Figures 7A to 7C This figure shows an embodiment in which the multipole electrode 108 is configured as an electrostatic dodecapole lens 701-712. The poles 701-712 that make up the electrostatic dodecapole lens all have identical shapes, and are capable of generating an electrostatic sextupole field in addition to the electrostatic deflection field. This provides the advantage of being able to correct the electrostatic sextupole field in addition to the electrostatic deflection field generated by the axial offset of the electric field suppression electrode 109.

[0068] When generating an electrostatic deflection field, such as Figure 7B As shown, when an electrostatic sextupole field is generated, Figure 7CAs shown in FIG. 1 , the voltage applied to each pole is controlled. By superimposing the voltages applied to each pole, an electrostatic deflection field and an electrostatic sextupole field can be generated in a superimposed manner.

[0069] In this manner, the configuration of the correction voltage source 113 connected to the multipole electrode 108 and the angular distribution of the electrodes (poles) constituting the multipole electrode 108 are determined based on the deflection field and the multipole field generated by the multipole electrode 108. Furthermore, in the above embodiments and modifications, the multipole electrode 108 is shown as an example in which the electrodes (poles) are formed by dividing a circular ring-shaped electrode into sections at a predetermined angular distribution. However, the electrodes (poles) may also be configured as parallel flat plates.

[0070] The magnitude of the electrostatic deflection field 115 generated by the axis deviation of the electric field suppression electrode 109 varies depending on the optical conditions. Therefore, the control unit 120 of the charged particle beam device stores Figure 8 Table 801 is shown. Table 801 records the optical conditions for multiple optical modes. In addition to the acceleration voltage, probe current, boost voltage, and deceleration voltage of the charged particle beam, it also records the voltage applied by the correction voltage source 113 to the multipole electrode 108. Furthermore, if there are multiple voltages applied by the correction voltage source 113, each voltage is recorded.

[0071] The control unit 120 implements sample observation using the optical mode selected by the user. Figure 9 As shown, the control unit 120 sends the correction voltage control signal corresponding to the optical mode selected by the user according to the table 801 to the correction voltage source 113, for example, through the DAC (Digital Analog Converter) 901 of the correction voltage source 113, to control the voltage value output by the correction voltage source 113.

[0072] The present invention is not limited to the above-described embodiments and includes various variations. For example, the above-described embodiments and variations are examples described in detail to facilitate understanding of the present invention and are not necessarily limited to having all the structures described. Furthermore, a portion of the structure of a particular embodiment or variation can be replaced with the structure of another embodiment or variation, and the structure of another embodiment or variation can be added to the structure of a particular embodiment or variation. Furthermore, other structures can be added, deleted, or substituted for a portion of the structure of each embodiment or variation.

[0073] Description of Reference Numerals

[0074] 101: Charged particle source, 102: Charged particle beam, 103: Objective lens, 104: Coil, 105: Upper magnetic circuit, 106: Lower magnetic circuit, 107: Main surface of objective lens, 108: Multipole electrode, 109: Electric field suppression electrode, 110: Sample, 111: Sample stage, 112: Lifting voltage source, 113: Correction voltage source, 114: Deceleration voltage source, 115, 116: Electrostatic deflection field, 120: Control unit, 201-204: Electrostatic quadrupole deflection electrodes, 211: X correction voltage source, 212: Y correction voltage source, 401: Solid insulating material, 402, 403: Triple point, 501-512: Electrostatic dodecapole deflection electrodes, 601-608: Electrostatic octupole lens, 701-712: Electrostatic dodecapole lens, 801: Table, 901: DAC.

Claims

1. A charged particle beam device, characterized in that The charged particle beam device comprises: a sample table on which the sample is placed; a charged particle optical system comprising a charged particle beam source; an objective lens having an upper magnetic circuit, a lower magnetic circuit, and a coil for focusing a charged particle beam emitted from the charged particle beam source on the sample; an electric field suppression electrode disposed between the objective lens and the sample stage and below a main surface of the objective lens, having an opening for allowing the charged particle beam to pass through; and a multipole electrode disposed between the objective lens and the electric field suppression electrode and below a main surface of the objective lens, having an opening for allowing the charged particle beam to pass through, for generating an electrostatic deflection field or an electrostatic field for the charged particle beam; a boost voltage source for applying a boost voltage to the upper magnetic circuit; a deceleration voltage source for applying a deceleration voltage to the sample, the lower magnetic circuit, and the electric field suppression electrode; as well as A calibrated voltage source causes the multipole electrodes to generate an electrostatic deflection field or an electrostatic multipole field.

2. The charged particle beam device according to claim 1, wherein The correction voltage source enables the multipole electrode to generate an electrostatic deflection field or a static electrode field, thereby canceling the electrostatic deflection field generated by the mismatch between the central axis of the electric field suppression electrode and the central axis of the objective lens.

3. The charged particle beam device according to claim 1, wherein The correction voltage source causes the multipole electrode to generate an electrostatic deflection field and an electrostatic multipole field, thereby canceling the electrostatic deflection field and the electrostatic multipole field generated by the misalignment between the central axis of the electric field suppression electrode and the central axis of the objective lens.

4. The charged particle beam device according to claim 1, wherein The electric field suppression electrode and the multipolar electrode are made of non-insulating and non-magnetic materials, respectively.

5. The charged particle beam device according to claim 4, characterized in that The electric field suppression electrode and the multipolar electrode are made of any one of single crystal silicon, molybdenum and titanium.

6. The charged particle beam device according to claim 1, wherein The charged particle beam device includes a solid insulating material provided between the electric field suppression electrode and the multipole electrode and having an opening for passing the charged particle beam.

7. The charged particle beam device according to claim 6, characterized in that An inner diameter of the opening of the solid insulating material is larger than an inner diameter of the opening of the electric field suppression electrode and an inner diameter of the opening of the multipolar electrode.

8. The charged particle beam device according to claim 7, wherein A protrusion is provided on a surface of the electric field suppression electrode facing the multipolar electrode in a region on the solid insulating material side and / or the vacuum side of a triple point of the electric field suppression electrode, the solid insulating material, and the vacuum.

9. The charged particle beam device according to claim 7, wherein A protrusion is provided on a surface of the multipolar electrode facing the electric field suppression electrode in a region on the solid insulating material side and / or the vacuum side of a triple point of the multipolar electrode, the solid insulating material, and the vacuum.

10. The charged particle beam device according to claim 6, wherein The material of the solid insulating material is an inorganic dielectric.

11. The charged particle beam device according to claim 10, wherein The material of the solid insulating material is any one of silicon dioxide, aluminum oxide, talc, sapphire and zirconium dioxide.

12. The charged particle beam device according to claim 1, wherein The height of the sample stage is variable.

13. The charged particle beam device according to claim 1, wherein When the sample is replaced, the potentials output by the boost voltage source, the deceleration voltage source, and the correction voltage source are set as reference potentials.

14. The charged particle beam device according to claim 1, wherein The charged particle beam device includes a control unit storing a table in which optical conditions of the charged particle optical system are registered for a plurality of optical modes. The control unit sets optical conditions of an optical mode selected from the plurality of optical modes for the charged particle optical system. The optical conditions of the charged particle optical system include a boost voltage value output by the boost voltage source, a deceleration voltage value output by the deceleration voltage source, and a voltage value output by the correction voltage source to the multipole electrode.

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