JP2019075392A - Charged particle beam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charged particle beam device for suppressing high-order off-axis chromatic aberration and the like generated when a beam is inclined or when a charged particle emitted from a sample is deflected. An objective lens (14) that focuses a charged particle beam emitted from a charged particle source, a detector (17) that detects a charged particle, and a beam from a direction different from the ideal optical axis of the objective lens. One or more deflectors (22) that deflect the charged particle beam or deflect the charged particles emitted from the sample toward the detector so as to irradiate, and the charged particle source and the objective lens. It includes an aberration correction unit (31) arranged between them, and optical elements (11, 32) arranged between the aberration correction unit and the objective lens and focusing a charged particle beam that has passed through the abnormality correction unit. We propose a charged particle beam device. [Selection diagram] Fig. 3

Description

  The present invention relates to a charged particle beam apparatus for irradiating a charged particle beam onto a sample, and more particularly to a charged particle beam apparatus capable of inclined beam irradiation.

  In the manufacturing process of semiconductor devices, a charged particle beam apparatus is used which performs dimension measurement of a pattern shape and defect inspection by irradiating a charged particle beam to an LSI and detecting secondary electrons generated from a sample. An electron microscope (Scanning Electron Microscope: SEM) is widely used. Conventionally, the performance improvement and cost reduction of semiconductor devices have been achieved by the improvement of the degree of integration due to the miniaturization, but in recent years the limit is being approached. In order to keep increasing the degree of integration, manufacture of devices having a three-dimensional structure is in progress. In order to improve the yield of three-dimensional devices, inspection and measurement equipment capable of acquiring information in the height direction in addition to conventional plane information is required.

  For this purpose, it is conceivable to tilt the beam (deflect the beam from the ideal optical axis of the beam and irradiate the beam to the sample from a direction different from the ideal optical axis). Patent Document 1 discloses a charged particle beam apparatus which tilts a beam to irradiate a sample. Moreover, in order to prevent the resolution deterioration at the time of beam inclination, Patent Document 1 is provided with two-stage deflection means for deflecting the charged particle beam in opposite directions in the convergent magnetic field of the objective lens. A method is disclosed for correcting off-axis chromatic aberrations that occur when tilting outside.

JP 2000-348658 A (Corresponding US Patent US Pat. No. 6,452,175)

  In a scanning electron microscope that observes a sample by tilting a beam, secondary electrons are deflected off axis and guided to the detector side in order to perform energy discrimination and analysis of secondary electrons and high-efficiency signal detection. Is desirable. On the other hand, secondary electrons are emitted from the sample, focused by the objective lens, and then diverged. A secondary electron exhibiting such behavior is used as a detection surface of a detector having a finite width or a secondary electron conversion electrode that generates secondary electrons (tertiary electrons) by collision of electrons (secondary electrons). If it tries to lead, depending on the extent of the divergence, high efficiency detection can not be performed. Also, according to the study of the inventors, when beam inclination is performed, curvature of field aberration occurs in the objective lens, and in order to correct this, adjustment using the objective lens is necessary. It became clear that the behavior of the next electron would change. Patent Document 1 discloses a method for correcting the aberration of primary electrons, but does not disclose a method for high efficiency detection of secondary electrons. Further, in the method disclosed in Patent Document 1, the primary electron is largely deflected by the two-stage deflector provided in the objective lens to cancel the aberration in the objective lens. Therefore, the secondary electrons are deflected further in the objective lens in the opposite direction to the primary electrons, and high efficiency detection can not be expected. For high-efficiency detection of secondary electrons, it is conceivable to properly control the trajectory of secondary electrons, but in the method of Patent Document 1, the effects of deflection aberration of the deflector and off-axis aberration of the objective lens are considered. We receive greatly. Therefore, it is difficult to independently control secondary electron trajectories without affecting primary electron trajectories at the time of tilt.

  In the following, a charged particle beam device is proposed for the purpose of suppressing high-order off-axis chromatic aberration or the like generated at the time of beam inclination or deflection of charged particles emitted from a sample.

  As one aspect for achieving the above object, an objective lens for focusing a charged particle beam emitted from a charged particle source, a detector for detecting charged particles, and a beam from a direction different from the ideal optical axis of the objective lens Between the charged particle source and the objective lens, and one or more deflectors for deflecting the charged particle beam or for deflecting the charged particles emitted from the sample towards the detector to illuminate the A charged particle beam device is proposed, which comprises an aberration correction unit disposed, and an optical element disposed between the aberration correction unit and the objective lens and focusing the charged particle beam that has passed through the aberration correction unit.

  According to the above aspect, it is possible to suppress high-order off-axis chromatic aberration or the like generated at the time of beam inclination or deflection of charged particles emitted from a sample.

The figure which shows the optical system configuration of a scanning electron microscope (schematic diagram of a 1st Example). Schematic of the optical system structure of 2nd Example. Schematic of the optical system structure of a 3rd Example. Schematic of the optical system structure of a 4th Example. Schematic of the optical system structure of a 5th Example. The block diagram of the EXB unit for secondary electron deflection of a 6th example. The block diagram of the Wien filter unit for secondary electron deflection of a 7th Example. The block diagram of the Wien filter unit for secondary electron deflection of the 8th example. The flowchart of the beam inclination of a 9th Example. FIG. 2 is a diagram illustrating the configuration of an optical system control unit. FIG. 8 is a diagram illustrating adjustment of the focusing position of the secondary electron trajectories of the first embodiment. FIG. 6 is a diagram showing the central orbit of primary electrons at the time of beam inclination in the first embodiment.

  The embodiment described below relates to a charged particle beam apparatus capable of beam inclination, and in particular to a charged particle beam apparatus which realizes suppression of aberration and high efficiency detection of charged particles (secondary electrons etc.) is there.

  The pattern shapes and materials of semiconductor devices continue to diversify, and in their inspections and measurements, they relate to secondary electrons, such as improving the yield of secondary electrons generated from a sample by primary electron beam irradiation, and material discrimination by energy discrimination. The demand for analysis is increasing. There is a need for a device with the ability to control secondary electron trajectories in order to perform high precision discrimination and analysis. Therefore, it is considered that inspection, measurement, and analysis of a three-dimensional device with a multilayer film structure in which different materials are stacked in the height direction is required, and the demand for an apparatus that can acquire both inclined image and secondary electron analysis at the time of inclination increases. Be

  In order to obtain information in the height direction by the SEM, an image may be obtained by irradiating a beam inclined to the sample. There are a mechanical tilt method and an electrical tilt method in the method of acquiring the tilt image in the SEM. In the in-line measurement and inspection, there is a method of mechanically tilting the sample stage or column, but the working distance between the objective lens and the sample (working distance: WD) is long to prevent interference with the wafer and column structure And the focal length of the objective lens becomes long. Therefore, the aberration of the objective lens can not be reduced and the resolution is degraded. Also, the mechanical action for tilting lowers the reproducibility of throughput, observation position and tilting angle.

  On the other hand, as an electrical tilt method, there is a beam tilt method of deflecting an electron beam by a deflector to tilt the electron beam with respect to a sample. In order to greatly surpass the mechanical tilt method in terms of the reproducibility of the throughput and the tilt angle, and the tilt angle and direction variability, an SEM of the electric beam tilt system is desired. However, in this method, when the beam is tilted, the off-axis aberration of the objective lens increases, the beam diameter increases, and the resolution deteriorates.

  Therefore, in the embodiment to be described below, an SEM is described in which the beam is inclined by the deflector (first deflector) and the optical element capable of suppressing the resolution reduction factor generated with the inclination is provided. Furthermore, the trajectory of secondary electrons or the like deflected by a deflector (second deflector) such as an orthogonal electromagnetic field generator (hereinafter referred to as EXB) which generates a deflection electric field and a deflection magnetic field at right angles to each other An SEM provided with an optical element appropriately guided to the detector side regardless of the inclination will be described. More specifically, in order to improve the energy discrimination of secondary electrons and the analysis accuracy, it is necessary to align the incident trajectories of the secondary electrons to the spectrometer. Also, in order to improve the signal yield, as many secondary electrons as possible should be guided to the detection surface of the detector. However, if the secondary electrons are spread on the secondary electron deflector, the orbit largely changes depending on the position on the EXB under the influence of the secondary aberration, which deviates from the incident conditions required for high accuracy discrimination and analysis. The secondary electrons may spread too much on the detection surface and the yield may decrease. Therefore, it is desirable to minimize the geometric aberration for the secondary electrons by forming the focal point of the secondary electrons on the secondary electron deflector.

  In addition, it is conceivable to adjust and correct the curvature of field generated by the beam passing off the axis of the objective lens by weakening the current and voltage of the objective lens itself for each tilt angle, but secondary electrons The lens action received from the objective lens weakens with the tilt angle, and the focusing position of the secondary electrons rises. Therefore, secondary electrons on the secondary electron deflector spread with the tilt angle, geometric aberration increases and discrimination accuracy decreases. Further, when the secondary electrons are deflected at the time of beam inclination, chromatic dispersion also occurs to the primary electrons, and chromatic aberrations other than the objective lens are generated, and the resolution at the time of inclination is degraded.

  In view of the above conditions, in the following embodiments, a charged particle beam source mainly for supplying charged particle beams, and a focusing position and a focusing angle of the charged particle beam emitted from the charged particle beam source are controlled. A plurality of condenser lenses, an objective lens for focusing the charged particle beam on the sample, a scanning means for scanning the charged particle beam on the sample, and detecting secondary electrons generated from the sample by the charged particle beam irradiation In a charged particle beam apparatus that tilts a beam to irradiate a sample and acquire a tilted image, a deflector that deflects primary electrons to tilt the beam (tilt deflector: first A deflector) and a secondary electron deflector (second deflector) disposed above the objective lens to separate the secondary electrons generated from the sample from the primary charged particle beam and to guide it to the detector; Sample and secondary electron deflection And a lens (secondary electron focusing lens: charged particle focusing lens) for focusing secondary electrons to the position of the secondary electron deflector, and a beam tilt disposed above the secondary electron deflector Aberration correction unit (aberration correction lens or multipole for generating aberration, deflector for generating aberration, high-order chromatic aberration suppressing optical element for focusing the primary electron beam with different energy on the principal surface of the objective lens), and the secondary electron A charged particle beam apparatus will be described which is provided with a lens (aberration characteristic compensation lens) that compensates for a change in aberration characteristic due to the secondary electron focusing lens disposed above the deflector.

  According to the above configuration, it is possible to perform three-dimensional observation technology capable of highly efficient signal detection and material discrimination with high accuracy in inspection and measurement of a shape pattern of a semiconductor.

  Hereinafter, a scanning electron microscope provided with a deflector for beam inclination will be described using the drawings. Although a scanning electron microscope is described as an example in the following embodiments, the following embodiments can also be applied to an ion beam irradiation apparatus for irradiating an ion beam.

  FIG. 1 is a schematic view of the optical configuration of the first embodiment. In the first embodiment, the case where a deflector and a lens are used to generate the aberration required for correcting the aberration of the primary electron at the time of beam inclination will be described.

  First, the operation in the case where the primary electrons are perpendicularly incident on the sample and the focusing position of the secondary electrons is not controlled will be described. A voltage is applied between the cathode 01 and the first anode 02 by the electron gun control unit 100, and the primary electrons 41 are emitted at a predetermined current density. An acceleration voltage is applied between the cathode 01 and the second anode 03 by the electron gun control unit 100, the primary electrons 41 are accelerated, and are ejected to the subsequent stage. After the primary electrons 41 are focused to a point P1 on the optical axis 30 by the first condenser lens 04 controlled by the first condenser lens control unit 101, the primary electrons 41 pass through the objective aperture 05 and unnecessary electrons are removed. The amount of probe current of the primary electrons 41 and the opening angle are determined by the position of the point P1 and the hole diameter of the aperture.

  Thereafter, a crossover of the primary electrons 41 is formed at a point P2 on the optical axis 30 by the second condenser lens 06 controlled by the second condenser lens control unit 102. The point P2 is set to coincide with the center position of the aberration generating deflector 08. Further, the primary electron 41 is incident on the aberration correction lens 09 controlled by the aberration correction lens control unit 105 to form a crossover at a point P3 on the object surface Zm of the objective lens. Since the high-order off-axis aberration suppression lens 11 is disposed centered on the object plane Zm, the primary electrons 41 are not subjected to the lens action of the high-order off-axis chromatic aberration suppression lens 11.

  Further, the electromagnetic field intensity of the secondary electron deflection EXB 22 controlled by the secondary electron deflection EXB control unit 110 is adjusted so that the central trajectory of the primary electrons 41 goes straight.

  Further, the light is incident on the objective lens 14 controlled by the objective lens control unit 113. The objective lens 14 has an opening through which the electron beam passes, and the center of the opening is the ideal optical axis of the electron beam (the passing trajectory of the electron beam when the beam is not deflected).

  A booster electrode 33 controlled by the objective lens control unit 113 is disposed, and the aberration of the objective lens 14 is reduced by applying an acceleration voltage. In addition, a decelerating voltage controlled by the retarding voltage control power supply 34 is applied to the stage 15 controlled by the stage control unit 115, and a decelerating electric field is formed between the sample 16 and the objective lens 14 to form an objective lens 14. Aberrations are further reduced. The primary electrons 41 incident on the objective lens 14 are focused on the sample 16 at a point Pi on the optical axis 30 to form a minute spot. The lens intensity of the objective lens 14 is determined by the working distance measured by the sample height measuring device 120. The minute spots of the primary electrons 41 irradiated to the sample 16 are planarly scanned on the sample 16 by the scanning deflector 13 controlled by the scanning deflector control unit 111.

  At this time, among the secondary electrons having a wide energy generated by the primary electrons 41 scanning the sample, the secondary electrons 42 of the energy of interest are subjected to a strong lens action by the objective lens 14. As a result, focusing is performed once by the action of the lens field on the sample side of the objective lens 14. After that, it is affected by the remaining lens field. At this time, the secondary electrons 42 are focused at a certain position according to the working distance, the lens strength of the objective lens 14, the accelerating electric field of the booster electrode 33, and the decelerating electric field of the sample 16. Thereafter, the secondary electrons 42 are deflected by the secondary electron deflection EXB 22 controlled by the secondary electron deflection EXB control unit 110, and are incident on the detector 17 controlled by the detector control unit 107 and detected as a signal. . The detection signal is calculated by the optical system control unit 116 and displayed on the image display unit 117 as a SEM image. When moving the field of view of the SEM image, the sample stage controlled by the stage control unit 114 is moved, or the image shift deflector 18 controlled by the scan deflector control unit 111 is operated to arrive the primary electrons 41 on the sample. Change the position. The control device 116 includes a storage medium (not shown), and executes the control described in the embodiments described later based on the optical conditions stored in the storage medium.

  In the present embodiment, the secondary electron focusing lens 21 is further disposed below the secondary electron deflection EXB 22, and the secondary electron focusing lens 21 is on the opposite side of the object plane Zm of the objective lens 14 and inclined. The aberration characteristic compensation lens 20 is disposed at a position below the light deflector 08.

In order to simultaneously correct primary off-axis chromatic aberration and deflection coma of the primary electron at the time of beam inclination, it is necessary that the ratio of aberration coefficient of deflection coma and axial chromatic aberration of the objective lens system and the aberration generating lens 09 be equal. The condition is the following equation (1).

However, C _s ^OBJ and C _c ^OBJ are the spherical aberration coefficient and the chromatic aberration coefficient of the combined lens of the magnetic field of the objective lens 14 defined by the objective lens object surface Zm, the accelerating electric field by the booster electrode 33 and the retarding electric field. C _s ^COR and C _c ^COR are the spherical aberration coefficient and the chromatic aberration coefficient of the aberration generating lens 09 defined by the objective lens surface Zm. In this embodiment, the aberration generating lens 09 is disposed, which satisfies the formula (1) when the lens 21 for focusing the secondary electron and the lens 20 for aberration characteristic compensation are off.

  Next, a method of focusing the secondary electrons 42 of the energy of interest at the inclination angle of 0 ° to the center of the secondary electron deflection EXB 22 will be described. FIG. 11A is a diagram showing a central orbit of primary electrons at the time of beam inclination when the secondary electron focusing lens 21 and the aberration characteristic compensation lens 20 are OFF. The secondary electrons 42 of the energy of interest are focused at a location out of the objective lens surface Zm.

  Next, current and voltage are applied to the secondary electron focusing lens 21 to operate. At this time, the voltage and current of the secondary electron focusing lens 21 operate in cooperation with the current change of the objective lens 14. Since the energy of primary electrons and secondary electrons are largely different, the refractive powers of the same lens are different. The intensities of the objective lens 14 and the secondary electron focusing lens 21 are simultaneously adjusted so that the secondary electrons 42 are focused to the point P3 on the object plane Zm of the objective lens 14 while focusing the primary electrons to the point Pi on the sample (FIG. 11B).

  When the secondary electron focusing lens 21 operates, the objective lens system at the time of beam inclination becomes a combined lens of the secondary electron focusing lens 21 in addition to the objective lens 14, the booster electrode 33 and the retarding electric field. Therefore, the spherical aberration coefficient and the chromatic aberration coefficient of the objective lens system are changed by the electromagnetic field of the secondary electron focusing lens 21. Since the electromagnetic field intensity is different for each tilt angle, these aberration coefficients change for each tilt angle.

Next, the aberration characteristic compensation lens 20 is operated. The aberration characteristic compensation lens 20 and the aberration generation lens 09 are simultaneously adjusted according to the changes of the secondary electron focusing lens 21 and the objective lens 14 so that the following equation (2) holds while keeping the focusing point P3 of the primary electrons The following equation (2) is established.

The spherical surface and chromatic aberration coefficients of the objective lens system defined by the object surface Zm of the objective lens including the secondary electron focusing lens 21 are composed of C ' _s ^OBJ and C' _c ^OBJ , and the composition of the aberration generating lens 09 and the aberration characteristic compensating lens 20 The spherical aberration coefficient and the chromatic aberration coefficient of the lens are respectively set as C ' _s ^COR and C' _c ^COR .

  By this operation, any working distance, lens strength of the objective lens 14, accelerating electric field of the booster electrode 33, focusing position of the secondary electron at no inclination with respect to strength of the decelerating electric field of the sample 16 can be used for secondary electron deflection EXB22. It can be set to the center P3 of.

  Next, the operation at the time of beam inclination will be described. FIG. 12 shows central orbits of primary electrons at the time of beam inclination. The primary electrons 43 are deflected by the aberration generating deflector 08 centered on the object point P2 of the aberration correcting lens 09 and pass off the axis of the aberration correcting lens 09. Then, it intersects with the optical axis at the center point P3 of the plane of symmetry Zm of the objective lens 14, is turned back by the tilt deflector 12 whose center coincides with P3 and passes off the axis of the objective lens 14 and tilts to the sample 16. While being irradiated.

  At this time, the primary electrons that have passed through the off-axis of the aberration generating lens 09 receive primary off-axis chromatic aberration, and are dispersed into the high energy primary electrons 44 and the low energy primary electrons 45. The lens intensity of the high-order off-axis chromatic aberration suppression lens 11 disposed on the object plane of the objective lens 14 is set such that the primary electrons dispersed by the aberration generation lens 09 are focused on the main surface of the objective lens 14. Since equation (2) holds, correction of primary off-axis chromatic aberration, deflection coma aberration and suppression of high-order off-axis chromatic aberration are performed. When the inclination angle and the inclination direction are changed, the deflection angle and the deflection direction of the primary electron 43 by the aberration generating deflector 08 and the inclination deflector 12 are changed.

  Next, the excitation current of the objective lens 14 is adjusted in order to correct the field curvature caused by passing the axis of the objective lens 14. Since the lens intensity of the objective lens 14 becomes weak, the focal point of the secondary electron 42 of the energy to be noticed shifts above the point P3 on the object plane Zm of the objective lens 14.

Next, the secondary electron focusing lens 21 and the objective lens 14 are simultaneously adjusted in the same manner as the adjustment at the time of no tilt, and the secondary electrons 42 of the objective lens 14 are focused while focusing the primary electrons to the point Pi on the sample. Focus on a point P3 on the object plane Zm. Since this adjustment differs depending on the tilt angle, the aberration coefficient changes for each tilt angle, and the ratio also changes. Let C ' _s ^OBJ (θ) and C' _c ^OBJ (θ) be the spherical surface and chromatic aberration coefficient of the objective lens system defined by the objective lens surface Zm including the secondary electron focusing lens 21 as a function of the inclination angle θ .

Next, the aberration characteristic compensation lens 20 is operated. The aberration characteristic compensation lens 20 and the aberration occurrence for each tilt angle according to the change of the secondary electron focusing lens 21 and the objective lens 14 so that the following equation (3) holds while always keeping the focusing point P3 of the primary electrons The lens 09 is adjusted at the same time.

However, the spherical aberration coefficient and the chromatic aberration coefficient of the compound lens of the aberration generating lens 09 and the aberration characteristic compensating lens 20 defined by the objective lens surface Zm when the inclination angle is θ are C ' _s ^COR (θ) and C, respectively. ^Let _{c c} ^COR (θ).

  According to this embodiment, simultaneous correction of primary off-axis chromatic aberration and deflection coma aberration of primary electrons with respect to an arbitrary beam tilt angle and tilt direction, suppression of high-order off-axis chromatic aberration generation and secondary electron focusing point secondary point It is possible to fix it at the position of the electron deflection EXB 22 and minimize the geometric aberration that the secondary electrons receive. In addition, since the size of the detection surface of the detector 17 is limited, the intensities of the secondary electron converging lens 21 and the objective lens 14 are set so that the secondary electron trajectory expanding as it is separated from the optical axis does not deviate from the detection surface. By adjusting, it becomes possible to realize highly efficient detection of secondary charged particles regardless of the degree of beam tilt.

  Further, when the secondary electrons are deflected by the secondary electron EXB22, color dispersion occurs in the primary electrons. In this embodiment, when the secondary electrons 42 are deflected by the load electron deflection EXB 22 because the secondary electron deflection EXB 22 is disposed so that the center coincides with the object plane Zm of the objective lens, it becomes primary electrons. The generated chromatic dispersion is focused on the sample by the objective lens 14 and becomes zero. In addition, high-order off-axis chromatic aberrations due to chromatic dispersion of primary electrons due to the secondary electrons EXB 22 do not become apparent in low-angle tilt and deflection where the tilt angle of the primary electrons and the secondary electron deflection angle are both 10 ° or less. Furthermore, since the primary electrons are focused at the center of the secondary electron deflection EXB 22, the effects of the secondary electron deflection EXB 22 on the focusing action, the astigmatic imaging action, and the primary electrons of the secondary aberration are minimized.

  In the present embodiment, even if the tilt angle is changed, the object plane Zm of the objective lens 14 always coincides with the center of the EXB 22 for secondary electron deflection, so a low angle tilt of 10 ° or less, deflection for secondary electron deflection Deterioration of resolution at the time of beam inclination by operation of EXB does not become apparent.

  According to the present embodiment, while performing aberration correction of the primary electrons at the time of beam inclination, the beam inclination which can minimize the geometric aberration that the secondary electrons receive from the secondary electron deflector 22 and perform energy discrimination of the secondary electrons with high accuracy. An optical system can be provided.

  In this embodiment, the tilt deflector 12 and the secondary electron deflection EXB 22 having different deflection fields generated for each tilt angle and tilt direction are disposed on the objective lens surface Zm. Therefore, the secondary electron deflection EXB generates a deflection field so as to cancel the deflection effect given to the secondary electrons by the tilt deflector 12 while maintaining the condition to make the primary electrons travel straight.

  Further, in the present embodiment, the tilt deflector 12 and the secondary deflection EXB 22 may be one deflection unit.

  Although the secondary electron focusing lens 21 is disposed above the objective lens 14 and the aberration characteristic compensating lens 20 is disposed below the aberration generating lens 09 in this embodiment, it may be disposed on the opposite side. .

  In the case where the energy of the secondary electron of interest is changed by changing the energy region of the secondary electrons to be discriminated in the present embodiment, or the acceleration voltage, the retarding voltage, the working distance, etc. are changed, The adjustment of the focusing position of the secondary electrons 42 may be performed again.

  Further, in the present embodiment, a plurality of detectors 17 may be provided, and detectors having different detection characteristics, detectors provided with an energy filter function, a spectroscope, etc. may be provided at the same time. At this time, when switching the detectors, the deflection direction and the angle of the secondary electrons 42 by the secondary deflection EXB may be set individually for each detector.

  Further, in the present embodiment, the focal point of the secondary electron 42 is fixed to the object plane Zm of the objective lens 14 by adjusting the intensity of the objective lens 14 and the secondary electron focusing lens 21. The accelerating voltage or the retarding voltage of the sample 16 may be adjusted in cooperation with the secondary electron focusing lens 21.

  The aberration characteristic compensation lens 20, the secondary electron focusing lens 21, the aberration generating lens 09, and the high-order off-axis chromatic aberration suppression lens 11 in this embodiment may be any of an electrostatic lens, a magnetic field lens, and an electromagnetic superposition lens. The aberration generating deflector 08 and the tilting deflector 12 may be either an electrostatic deflector or a magnetic deflector.

  In the present embodiment, a suitable configuration is provided in the case where the secondary electron deflection EXB 22 can not be disposed on the object plane Zm of the objective lens 14 due to design restrictions in the first embodiment. FIG. 2 is a schematic view of the configuration of the optical system of this embodiment. In this embodiment, the secondary electron deflection EXB 22 is disposed between the high-order off-axis chromatic aberration suppression lens 11 and the secondary electron focusing lens 21 disposed at the object plane position Zm of the objective lens 14. Further, the dispersion adjustment EXB 23 is newly disposed between the secondary electron deflection EXB 22 and the high-order off-axis chromatic aberration suppression lens 11. The detector 17 is disposed between the dispersion adjustment EXB 23 and the secondary electron deflection EXB 22.

  In this embodiment, the intensities of the objective lens 14 and the secondary electron focusing lens 21 are set so that the secondary electrons 42 are focused on the central point Ps of the EXB 22 for secondary electron deflection and the object plane Zm of the objective lens 14 is fixed. Is adjusted. The lens strength of the aberration generating lens 09 and the aberration characteristic compensating lens 20 is adjusted for each tilt angle so that the expression (3) always holds while the object plane Zm of the objective lens 14 is fixed. As a result, correction of primary off-axis chromatic aberration and deflection coma aberration, suppression of high-order off-axis chromatic aberration, and focusing position of secondary electrons are fixed at the center Ps of the secondary electron deflection EXB 22 at the time of beam inclination of primary electrons. The secondary electrons 42 are deflected toward the detector 17 by the secondary electron deflection EXB 22.

  However, since the secondary electron deflection EXB 22 is apart from the object plane Zm of the objective lens 14, the color dispersion given by the secondary electron deflection EXB to the primary electrons becomes apparent. The dispersion adjustment EXB 23 makes the primary electrons of average energy travel straight, and the dispersion starting point of the primary electrons of different energies from the EXB 22 for secondary electron deflection is virtually the central point P3 of the object plane Zm of the objective lens 14 To be adjusted. As a result, the chromatic dispersion of the primary electrons generated by the dispersion adjustment EXB 23 and the secondary electron deflection EXB 22 is focused on the sample 16 by the objective lens 14 and becomes zero and does not become apparent.

  In this embodiment, since the primary electrons are spread on the secondary electron deflection EXB 22 and the dispersion adjustment EXB 23, the lens action and astigmatism effect of EXB are received. However, in this embodiment, the intensities of the secondary electron deflection EXB 22 and the dispersion adjustment EXB 23 are fixed regardless of the inclination angle and the inclination direction. Therefore, the astigmatic imaging action can be corrected by adjusting the astigmatic corrector 07 when it is not inclined. In addition, adjustment of the objective lens 14, secondary electron focusing lens 21, aberration generating lens 09, and aberration characteristic compensation lens 20 without inclination is performed after taking into consideration the lens action of the EXB 22 for secondary electron deflection and EXB 23 for dispersion adjustment. Just do it.

  In this embodiment, in the first embodiment, the color dispersion given to the primary electrons by the secondary electron deflecting EXB 22 at the time of beam inclination is high when the inclination angle is 10 ° and the secondary electron deflection angle is a large angle of 10 ° or more. The present invention provides a suitable configuration that does not generate high-order off-axis chromatic aberration in the case where secondary off-axis chromatic aberration is realized.

  FIG. 3 is a schematic view of the configuration of this embodiment. In this embodiment, the secondary electron deflection EXB 22 is disposed between the high-order off-axis chromatic aberration suppression lens 11 and the secondary electron focusing lens 21 disposed at the object plane position Zm of the objective lens 14. The detector 17 is disposed between the high-order off-axis chromatic aberration suppression lens 11 and the secondary electron deflection EXB 22. In addition, the second EXB 32 for dispersion compensation is disposed at the same position as the high-order off-axis chromatic aberration suppression lens 11. A dispersion compensating first EXB 31 which is the same EXB as the EXB 22 for secondary electron deflection is disposed at a symmetrical position across the object plane Zm of the objective lens 14.

  In this embodiment, as in the second embodiment, the objective lens 14, the secondary electron focusing lens 21, the aberration generating lens 09, and the aberration characteristic compensating lens 20 are adjusted for the secondary electron deflection EXB 22 and the dispersion compensation first EXB 31. In consideration of the lens function, the focal point of the secondary electron 42 is fixed to the central point Ps of the EXB 22 for secondary electron deflection.

  The EXB 22 for secondary electron deflection and the first EXB 31 for dispersion compensation are exactly the same EXB, and the intensities of the generated bipolar electromagnetic fields are also the same. However, when the high-order off-axis chromatic aberration suppression lens 11 is a magnetic field lens, the generation direction of the dipole electromagnetic field is rotated by the rotation angle.

The action on these primary electrons of EXB will be described. Dispersion of the primary electrons occurs due to the dispersion compensating first EXB 31. The chromatic dispersion generated starting from the center P _A of the first EXB31 dispersion compensation. Second EXB32 for dispersion compensation, including the lens action of the first EXB31 chromatic dispersion higher shaft outer chromatic aberration suppression lens 11 generated by the dispersion compensation dipole to focus to the center P _S of the secondary electron deflecting EXB22 Generate a place. Furthermore, the chromatic dispersion of the secondary electron deflection EXB 22 is added, and the chromatic dispersion is completely corrected after passing through the secondary electron deflection EXB 22. Accordingly, the chromatic dispersion of the secondary electron deflection EXB is zero on the main surface of the objective lens 14, and high-order off-axis chromatic aberration is not generated even at large angle inclination and large angle secondary electron deflection.

  Further, in this embodiment, since the electromagnetic field intensity, direction, and distribution of the secondary electron deflection EXB 22 in which the primary electrons are spread and the dispersion compensating first EXB 31 are symmetrical with respect to the primary electron focusing surface Zm, the secondary electron deflection EXB 22 and the secondary electron deflection EXB 22 The secondary aberration to the primary electrons of the dispersion compensating first EXB 31 is simultaneously corrected.

  Further, the present embodiment is not limited to the symmetrical arrangement of the secondary electron deflecting EXB 22 and the dispersion compensating first EXB 31. From the bottom, three EXB's for secondary electron deflection EXB22, dispersion compensation second EXB32, and dispersion compensation first EXB31 are arranged, and if the dipole field strength and direction of each EXB are properly set, electromagnetic field distribution, Regardless of the arrangement, chromatic dispersion due to EXB can be completely corrected, and large-angle tilt and large-angle secondary electron deflection can be realized as long as the second-order aberration of EXB does not become apparent.

  In the first, second and third embodiments, the aberration for correcting the aberration of the objective lens at the time of beam inclination is generated by the aberration generating lens 09 and the aberration generating deflector 08 which transmits primary electrons out of the axis thereof And a lens for suppressing high-order off-axis chromatic aberration at the time of beam inclination.

  The unit for correction aberration generation at the time of beam inclination and high-order off-axis chromatic aberration suppression in the present embodiment is not limited to the above configuration, and a multipole element may be used. In this embodiment, a multipole element for aberration correction is used as the aberration generation unit when oblique, and a multipole element capable of generating a quadrupole field as an optical element for suppressing high-order off-axis chromatic aberration will be described.

  FIG. 4 is a schematic view of the configuration of this embodiment. In this embodiment, in the optical system configuration of the first embodiment, an aberration generating multipole element 50 is disposed between the aberration characteristic compensating lens 20 and the second condenser lens 06 instead of the aberration generating lens 09. . On the object plane Zm of the objective lens 14, the tilt deflector 12, the secondary electron deflection EXB 22, and the high-order off-axis chromatic aberration suppression multipole element 51 are disposed.

  The primary electrons are appropriately spread on the aberration generating multipole 50, and are focused at the center point P3 of the high-order off-axis chromatic aberration suppressing multipole 37 so as not to generate extra aberrations for the primary electrons.

  The aberration generating multipole element 50 is adjusted to generate chromatic aberration and coma aberration equivalent to the objective lens 14 on the object plane Zm of the objective lens 14.

  Similar to the first embodiment, the objective lens 14 and the secondary electron focusing lens 21 focus the primary electrons on the sample and the secondary electrons 42 at the center point of the secondary electron deflection EXB 22 according to the beam inclination angle. Work in concert to focus on P3.

  In addition, primary electrons are always focused at the center point P3 of the multipole 51 for high-order off-axis chromatic aberration suppression for each tilt angle and direction, and chromatic dispersion and secondary coma are generated with the same amount and opposite sign as the objective lens system. In addition, the intensities of the aberration generating multipole element 50 and the aberration characteristic compensating lens 20 are adjusted in cooperation for each tilt angle.

  The multipole element 51 for suppressing high-order off-axis chromatic aberration generates a quadrupole field. The astigmatism produced by the quadrupole field focuses the chromatic aberration generated by the aberration generating multipole element 50 on the main surface of the objective lens 14 in order to correct the chromatic aberration at the time of beam inclination. As a result, the occurrence of high-order off-axis chromatic aberration is suppressed. When changing the inclination angle and the inclination direction of the beam, the multipole strength and direction of the aberration generating multipole 50 may be changed, and the direction of the quadrupole field of the high order off-axis chromatic aberration suppressing multipole 51 may be changed.

  In this embodiment, since the secondary electron deflecting EXB 22 is disposed on the object plane Zm of the objective lens 14, the color dispersion provided by the secondary electron deflecting EXB 22 to the primary electrons is zero on the sample 16 as in the first embodiment. There is no problem at the time of low angle tilt and secondary electron low angle deflection because it does not become apparent.

  When large angle tilt and secondary electron large angle deflection are performed, two stages of dispersion compensation EXB may be disposed above the EXB 22 for secondary electron deflection as in the third embodiment.

  A unit in which a deflector is added between the second condenser lens 06 and the aberration generating multipole 50 is used as an aberration generating unit, and primary electrons are allowed to pass out of the axis of the aberration generating multipole 51 to generate chromatic aberration and coma. You may adjust the ratio.

  The aberration-generating multipole element 50 and the high-order aberration suppressing multipole element 51 in this embodiment may be any of an electrostatic type, a magnetic field type, and an electromagnetic superposition type.

  In this embodiment, the case where a Wien filter is used as an aberration generation unit at the time of beam inclination and a suppression optical element of high-order off-axis chromatic aberration will be described.

  FIG. 5 is a schematic diagram out of the configuration of this embodiment. In the present embodiment, instead of the aberration generating lens 09, an aberration generating Wien filter 36 is disposed between the aberration characteristic compensating lens 20 and the second condenser lens 06. The tilt deflector 12 and the high-order off-axis chromatic aberration suppression Wien filter 37 are disposed on the object plane Zm of the objective lens 14. The deflection field of the tilt deflector 12 may be superimposed on the high-order off-axis chromatic aberration suppression Wien filter 37. The secondary electron deflection EXB 22 is disposed between the secondary electron focusing lens 22 and the high-order off-axis chromatic aberration suppression Wien filter 37, and the detector 17 is a secondary electron deflection EXB 22 and high-order off-axis chromatic aberration suppression It is disposed between the Wien filters 37.

  The primary electrons are properly spread on the aberration generating Wien filter 36, and are focused at the center point P3 of the high-order off-axis chromatic aberration suppressing Wien filter 37 so as not to generate unnecessary aberrations for the primary electrons.

  The aberration-generating Wien filter 36 generates chromatic dispersion and secondary aberrations of the primary electron according to the strength and direction of the dipole field. In the present configuration, of the generated secondary aberrations, secondary coma aberration is used for aberration correction at the time of beam inclination of the objective lens 14. The aberration-generating Wien filter 36 is adjusted to generate chromatic dispersion and second-order coma aberration equivalent to the objective lens 14 on the object plane Zm of the objective lens 14.

Similar to the first embodiment, the objective lens 14 and the secondary electron focusing lens 21 focus the primary electrons on the sample and the secondary electrons 42 at the center point of the secondary electron deflection EXB 22 according to the beam inclination angle. cooperatively operate so as to converge to P _S.

  In addition, primary electrons are always focused at the center point P3 of the Wien filter 37 for high-order off-axis chromatic aberration suppression for each tilt angle and direction, and chromatic dispersion and secondary coma are generated with the same amount and opposite sign as the objective lens system. In addition, the intensities of the aberration generating Wien filter 36 and the aberration characteristic compensating lens 20 are adjusted in cooperation for each inclination angle.

  The Wien filter 37 for high-order off-axis chromatic aberration suppression is operated to generate a dipole field so as to focus the chromatic dispersion generated by the aberration-generating Wien filter 36 on the main surface of the objective lens 14. When changing the tilt angle and the tilt direction, it is sufficient to change the generation intensity and direction of the dipole field and the quadrupole field of the Wien filter 36 for generating aberration and the Wien filter 37 for high-order off-axis chromatic aberration suppression.

  Next, correction of chromatic dispersion of secondary electron orbits will be described. In this embodiment, the Wien filter 36 for generating aberration and the Wien filter 37 for suppressing high-order off-axis chromatic aberration play a role of the dispersion compensating second EXB 32 in the third embodiment. The chromatic aberration is generated in the deflection direction of the secondary electrons by the Wien filter 36 for generating aberration and the Wien filter 37 for suppressing high-order off-axis chromatic aberration so as to correct the chromatic dispersion generated in the primary electrons by the operation of the secondary electron deflector 22 It suffices to superimpose a bipolar field so that The intensity and direction of the superimposed field are set according to the energy of the secondary electron of interest, the deflection direction, and the deflection angle. As a result, the generation of high-order off-axis chromatic aberration of primary electrons at the time of beam inclination is suppressed.

  According to this embodiment, even if a Wien filter is used as an aberration generation unit and an optical element for suppressing high-order off-axis chromatic aberration, aberration correction of primary electrons at beam tilt and control of focusing position for high accuracy discrimination of secondary electrons are possible. compatible.

  A unit in which a deflector is added between the second condenser lens 06 and the Wien filter 36 for aberration generation is used as an aberration generating unit, and primary electrons are allowed to pass out of the axis of the Wien filter 36 for aberration generation. The aberration generation ratio may be adjusted.

  In the first, second, third, fourth and present embodiments, the aberration generating optical element may be any of a lens, a multipole element, and a Wien filter. Further, the optical element for suppressing high-order off-axis chromatic aberration may be either a lens, a multipole capable of generating a quadrupole field, or a Wien filter.

  In this embodiment, an example of a configuration for arranging the centers of the high-order chromatic aberration suppression lens 11 and the secondary electron deflection EXB 22 in the same position in the configuration of the first embodiment will be described.

  FIG. 6 is a cross-sectional view showing the configuration of the lens and the EXB in the present embodiment. 6A is an XZ sectional view, and FIG. 6B is an XY sectional view of the objective lens 14 at the position of the object plane Zm. The electrodes 150 to 153 of paramagnetic metal are disposed with the object plane Zm as the center of symmetry in the Z direction, and the deflection coils 154 to 157 not using a ferromagnetic core in a coil form are disposed outside them to form EXB. In addition, a coil 158 for the magnetic field circular lens is disposed outside the EXB, and these components are casingd by a circular lens magnetic path 159 of ferromagnetic metal. Although not shown, each electrode and coil are connected with a power source for supplying a deflection dipole electric field, a deflection dipole magnetic field, a voltage for generating a circular lens magnetic field, and an electric current. These power supplies are controlled by the secondary electron deflection EXB control unit 110.

  In the configuration of the present embodiment, electrostatic shielding of the generated electric field can be prevented by disposing the electrode generating the deflection dipole electric field of EXB at the innermost side. Further, by using a paramagnetic metal as the electrode material, the generation of a dipole magnetic field or a circular lens magnetic field is not inhibited. Also, by not using a ferromagnetic core in the winding type of coils 154 to 157 for generating a dipole magnetic field, a deflection dipole magnetic field is generated without preventing generation of a circular lens magnetic field by the coil for circular lens 158 disposed at the outermost side. it can.

  In this embodiment, the number of electrodes of EXB for secondary electron deflection is set to 8 poles to 12 poles, or the azimuth distribution of the number of turns of deflection coils is adjusted to generate a multipole field having a hexapole field or more. You may suppress it.

   In this embodiment, in the configurations of the first to third embodiments, a second configuration for aligning the centers of the high-order chromatic aberration suppression lens 11 and the EXB 22 for secondary electron deflection in the same position will be described. .

  In the present embodiment, the electrode of the secondary electron deflection EXB and the magnetic pole are used as a common electromagnetic pole, and the distributions of the electric field and the magnetic field are made to coincide with each other to form a Wien filter unit. FIG. 7 is a cross-sectional view showing the configuration of the Wien filter unit. In the present embodiment, four electromagnetic poles 201, 202, 203 and 204 are arranged so as to rotate by 90 ° in the azimuth direction. Each electromagnetic pole is made of a ferromagnetic metal, and a coil for magnetic field excitation is wound. Although not shown, DC power supplies are connected to the respective magnetic poles and coils independently.

  When the same voltage is applied to the electromagnetic poles 201 to 204, the four electromagnetic poles are brought to the same potential to generate an electrostatic circular lens field. However, an electrostatic octupole field is generated at the same time. When the voltage is positive, an accelerating lens is generated, and when the voltage is negative, a decelerating lens field is generated.

  A dipole electric field can be generated in any direction by superimposing voltages independently on each of the magnetic poles 201 to 204 while applying a voltage for generating an electrostatic circular lens field to all the magnetic poles. Further, by appropriately supplying current to the coil for exciting the magnetic pole, it is possible to generate a bipolar magnetic field in any direction.

  The present embodiment is also suitable as the configuration of the EXB and Wien filters used in the first, second, third and fourth embodiments.

  In the Wien filter unit shown in the seventh embodiment, an electrostatic octupole field is generated together with the electrostatic circular lens field. The octupole field generates third-order geometric aberration and third-order chromatic aberration. These aberrations may become apparent as the beam tilt angle or the secondary electron deflection angle increases. Therefore, a Wien filter unit using eight electromagnetic poles will be described here as a further preferred example. FIG. 8 is a cross-sectional view showing the configuration of this embodiment.

  The Wien filter unit comprises eight electromagnetic poles 211 to 218 and a coil for exciting the electromagnetic poles. The power supply which supplies a voltage and an electric current independently is connected to each electromagnetic pole and coil.

  When the same voltage is applied to eight electromagnetic poles, an electrostatic hexapole field is generated together with the electrostatic circular lens field. The aberrations of the electrostatic hexapole field are seventh order geometric aberration and seventh order chromatic aberration. These aberrations are negligible because they do not cause any problems in practical use. In this configuration, by independently applying voltage and current to eight electromagnetic poles, it is possible to generate a dipole electric field, a dipole magnetic field and a quadrupole electric field, and a quadrupole magnetic field in any direction in addition to the electrostatic circular lens field.

  In addition, the number of electromagnetic poles may be 12, and a circular lens field, a dipole field, a quadrupole field, and a hexapole field may be generated arbitrarily.

  Also, circular lens magnetic field, octupole magnetic field, and hexapole magnetic field can be generated in the same way as the current flows in the electromagnetic pole excitation coil of the Wien filter unit so that all the magnetic poles excite the N pole or S pole. .

  Further, this embodiment is most suitable as the configuration of the EXB and Wien filter used in the first, second, third, fourth and fifth embodiments. Since the quadrupole field can be freely generated in addition to the dipole field, it is possible to cancel the astigmatic imaging action of the Wien filter while achromatizing the quadrupole. It is also optimum as the configuration of the multipole element for suppressing high-order off-axis chromatic aberration in the fourth embodiment.

  In this embodiment, a control flow of primary electrons and secondary electrons at the time of beam inclination will be described. FIG. 10 is a diagram showing the configuration of the optical system control unit 116. As shown in FIG. FIG. 9 is a flow chart of beam inclination of primary electrons according to this embodiment.

  At step 001, optical conditions (acceleration voltage, booster voltage, retarding voltage, energy of secondary electrons to be focused) to be observed are set by the optical condition setting unit 301.

  At step 002, the sample stage is moved to the observation position.

  In step 003, the working distance is measured by the sample height measuring device 120.

  At step 004, a detector for image acquisition is selected.

  In step 005, the inclination angle and the inclination direction are input.

At step 006, according to the optical condition set at step 001, the detector selected at step 004, the tilt angle and tilt direction inputted at step 005, deflector operating condition recording unit 303, lens operating condition recording unit 304, EXB operating condition The recording condition 305 stored in the recording unit 305 and the astigmatism correction device operation condition recording unit 306 is read out, and each lens, each EXB or Wien filter, each operation is performed by the operation condition calculation unit 302 based on the working distance measured in step 003. The voltage and current of the multipole element, each deflector, and the astigmatism corrector are determined and set through each control unit.

  At step 007, the focus and the stigma are finely adjusted. At this time, in the fine focus adjustment, in step 005, the lens intensities of the objective lens 14 and the secondary electron focusing lens 20 change in conjunction with each other based on the calculated operating conditions, and the focusing position of the secondary electrons does not change. , Is performed so as to change only the focus of the primary electrons.

  At step 008, a tilted SEM image is acquired.

  In step 009, it is determined whether or not it is necessary to change the tilt angle and the direction.

  In step 010, it is determined whether it is necessary to change the detector for acquiring an image.

  In step 110, it is determined whether or not the sample observation position needs to be changed.

  01: Cathode, 02: First anode, 03: Second anode, 04: First condenser lens, 05: Objective aperture, 06: Second condenser lens, 07: Astigmatic corrector, 08: Aberration generating deflector, 09: Aberration generating lens, 11: High order chromatic aberration suppression lens, 12: Tilting deflector, 13: Scanning deflector, 14: Objective lens, 15: Sample stage, 16: Sample, 17: Detector, 18: Image Shift deflector, 20: lens for aberration characteristic compensation, 21: lens for secondary electron focusing, 22: EXB for secondary electron deflection, 23: EXB for dispersion adjustment, 30: optical axis, 31: dispersion compensated first EXB, 32: Dispersion compensation 2nd EXB, 33: Booster electrode, 34: Retarding voltage application power source, 35: Orbit adjustment deflector, 36: Wien filter for aberration generation, 37: Wien filter for high-order off-axis chromatic aberration suppression 41: primary electrons, 42: secondary electrons, 43: central orbits of primary electrons of average energy, 44: central orbits of low energy primary electrons, 45: central orbits of high energy primary electrons, 50: multiple for aberration correction Poles, 51: multipoles for suppressing high-order off-axis chromatic aberration, 100: electron gun control unit, 101: first condenser lens control unit, 102: second condenser lens control unit, 103: astigmatism controller control unit, 104: Aberration generating deflector control unit 105: aberration generating lens control unit 106: aberration characteristic compensating lens control unit 107: detector control unit 108: high order chromatic aberration suppressing lens control unit 109: tilt deflector Control unit 110: EXB control unit for secondary electron deflection 111: scanning deflector control unit 112: lens control unit for secondary electron focusing 113: objective lens control unit 114: sample stage control Part, 116: Optical system control part, 120: Sample height measuring instrument, 150: Electrode, 151: Electrode, 152: Electrode, 153: Electrode, 154: Coil, 155: Coil, 156: Coil, 157: Coil, 158 : Coil for circular lens magnetic field, 159: magnetic path, 201: electromagnetic pole, 202: electromagnetic pole, 203: electromagnetic pole, 204: electromagnetic pole, 211: electromagnetic pole, 212: electromagnetic pole, 213: electromagnetic pole, 214: electromagnetic Pole, 215: Electromagnetic pole, 216: Electromagnetic pole, 217: Electromagnetic pole, 218: Electromagnetic pole, 301: Optical condition setting unit, 302: Operating condition calculation unit, 303: Deflector operating condition recording unit, 304: Lens operating condition Recording unit 305: EXB operation condition recording unit 306: astigmatism correction device operation condition recording unit

Claims (9)

  An objective lens for focusing a charged particle beam emitted from a charged particle source, a detector for detecting charged particles, and the charged particle beam so as to irradiate the beam from a direction different from the ideal optical axis of the objective lens Deflection or one or more deflectors for deflecting the charged particles emitted from the sample towards the detector, an aberration correction unit disposed between the charged particle source and the objective lens, the aberration correction A charged particle beam apparatus comprising an optical element disposed between a unit and the objective lens and focusing a charged particle beam that has passed through the aberration correction unit. In claim 1,
The charged particle beam device, wherein the optical element is a lens for focusing the charged particle beam with different energy on the principal surface of the objective lens, a Wien filter, or a multipole for generating a quadrupole field. In claim 1,
Among the one or more deflectors, a charged particle deflector for deflecting charged particles emitted from a sample is disposed between the objective lens and the object surface of the objective lens, and the charged particle deflector and the optical A charged particle beam device characterized in that a dispersing deflector for dispersing the charged particle beam is disposed between the element and the element. In claim 3,
The control device controls the dispersion deflector such that the origin of the dispersion of the charged particle beam that has passed through the dispersion deflector is virtually an object surface of an objective lens. Particle beam equipment. In claim 3,
The charged particle beam device, wherein the dispersion deflector is an orthogonal electromagnetic field generator.   An objective lens for focusing a charged particle beam emitted from a charged particle source; a detector for detecting charged particles obtained by irradiating the sample with the charged particle beam; and deflecting the charged particles toward the detector A first orthogonal electromagnetic field generator; a second orthogonal electromagnetic field generator that compensates for the dispersion of the charged particle beam by the first orthogonal electromagnetic field generator; a first orthogonal electromagnetic field generator; A focusing element disposed between the two orthogonal field generators and including at least one of a third orthogonal field generator and a focusing lens; and at least one of the third orthogonal field generator and the focusing lens Controller for controlling the charged particle beam emitted by the second orthogonal electromagnetic field generator to focus on the deflection point of the first orthogonal electromagnetic field generator. Third orthogonal electromagnetic field and a charged particle beam device for controlling at least one of the focusing lens. In claim 6,
A charged particle focusing lens disposed between the first orthogonal electromagnetic field generator and the objective lens, wherein the charged particle focusing lens focuses charged particles emitted from a sample at the deflection point. Wire equipment. In claim 6,
The electric field generated by the first orthogonal electromagnetic field generator and the electromagnetic field generated by the second orthogonal field generator are charged with their intensity, direction, and distribution symmetrical with respect to the object plane of the objective lens Particle beam equipment. In claim 6,
A charged particle beam device, wherein the first orthogonal electromagnetic field generator and the second orthogonal electromagnetic field generator generate electromagnetic fields of the same intensity.

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