JP5397060B2 - Charged particle microscope and analysis method - Google Patents

Description

  The present invention relates to a charged particle microscope that performs observation and analysis of a sample using charged particles (electrons, ions, and the like) and an analysis method that improves the resolution of the charged particle microscope.

  A scanning transmission electron microscope (STEM) can obtain an observation image with extremely high spatial resolution by scanning a very small and converged electron beam probe in a direction parallel to the sample surface. In addition, the scanning transmission electron microscope includes a detector that detects X-rays emitted from a sample upon irradiation with an electron beam, a detector that detects an energy loss spectrum of electrons scattered by the sample, and the like. Thereby, analysis evaluation can be performed by associating the observation position with the measured value or the physical property value. Therefore, the scanning transmission electron microscope is widely used for the development of semiconductor devices.

  With the recent miniaturization of semiconductor devices, scanning transmission electron microscopes are required to have higher resolution. In order to increase the resolution of the scanning transmission electron microscope, it is conceivable to further reduce the probe size (diameter) of the electron beam. However, if the probe size is extremely small, the amount of current is also small, so that analysis and evaluation cannot be performed with good accuracy. In addition, since the electron beam incident on the sample interacts with the sample and the probe size increases, there is a limit to improving the spatial resolution even if the probe size is reduced. Therefore, it has been proposed to improve the resolution by performing arithmetic processing on data obtained by an electron microscope.

Japanese Patent Laid-Open No. 10-227750 JP-A-6-163373 JP 2000-82437 A

  As described above, conventionally, it has been proposed to improve the resolution by performing arithmetic processing on data obtained by an electron microscope. However, in the conventional method, the effective probe size of the electron beam is not considered, and there is a problem that the resolution cannot be sufficiently improved or quantitative analysis cannot be performed.

  In view of the above, an object of the present invention is to provide a charged particle microscope and an analysis method capable of further improving the resolution as compared with the conventional case.

  According to one aspect, in a charged particle microscope analysis method for analyzing a sample by scanning a focused charged particle beam along the surface of the sample, the shape and size of the charged particle beam spread in the sample And a process of obtaining intensity distribution data of the charged particles, and scanning the charged particle beam along the surface of the sample while irradiating the sample with the charged particle beam, and irradiating the charged particle beam for each analysis target position. The analysis target position is irradiated for each analysis target position from the step of measuring the phenomenon that occurs with the measuring instrument and the data of the shape and size of the charged particle beam spread in the sample and the intensity distribution of the charged particle. Calculating a charged particle dose and a charged particle dose irradiated to the periphery thereof, and performing an operation for eliminating the influence of the surrounding of the analysis target position on the measurement value obtained by the measuring device based on the result. Have Analysis method is provided.

  Note that phenomena that occur with irradiation of charged particle beams include X-ray emission, diffraction of charged particle beams, and energy loss of charged particle beams.

  When irradiating a charged particle beam to the analysis target position, if the size of the analysis target position is small, the charged particle beam is also irradiated around the analysis target position, and the target analysis result has an influence on the target analysis position. It will be included.

  In the analysis method according to the above aspect, data on the shape and size of the charged particle beam spread in the sample and the intensity distribution of the charged particle are acquired. As a result, the influence around the analysis target position can be estimated, and a true measurement value at the analysis target position can be obtained by performing an operation that eliminates the influence around the analysis target position from the measurement value obtained by the measuring instrument. Can do. As a result, the resolution of the charged particle microscope is improved.

For the calculation to eliminate the influence of the surrounding area of the analysis target position, for example, the measurement value excluding the influence of the surrounding area at the analysis target position is set as A _calc, and the intensity of the charged particle beam irradiated to the analysis target position is set as I _A. When the intensity of the charged particle beam irradiated around the position is I _B , the measurement value at the analysis target position is A _exp, and the measurement value around the analysis target position is B _exp , A _calc = A represented by _{exp × I A -B exp × I} B.

FIG. 1 is a schematic diagram illustrating a structure of a charged particle microscope (scanning transmission electron microscope: STEM) according to the embodiment. 2A is a conceptual diagram showing a STEM-EELS spectrum imaging method using an EELS detector, and FIG. 2B is a diagram showing an example of an EELS spectrum obtained from the output of the EELS detector. FIG. 3 is a schematic diagram showing an example of an EELS spectrum continuous along the scanning direction. 4A and 4B are schematic diagrams showing the concept of continuous multipoint analysis. FIGS. 5A to 5C are diagrams showing the influence of the probe size in a sample in which two kinds of materials are arranged in contact with each other. FIG. 6 is a diagram showing the shape (intensity distribution) of the electron beam probe obtained by the simulation calculation. FIGS. 7A to 7C are views in which the shape of the electron beam probe is similarly displayed three-dimensionally. FIGS. 8A and 8B are diagrams showing an outline of the analysis method according to the embodiment. FIG. 9 is a flowchart illustrating the analysis method according to the embodiment. FIG. 10 is a diagram illustrating an example of an image of an effective probe.

  Hereinafter, embodiments will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram illustrating a structure of a charged particle microscope (scanning transmission electron microscope: STEM) according to the embodiment.

  As shown in FIG. 1, the scanning transmission electron microscope according to the present embodiment includes a control unit 10, an electron gun 11, converging lenses 12a and 12b, a converging lens diaphragm 13, a scanning coil 15, and an EDS (Energy). (Dispersive x-ray Spectroscopy) detector 17, objective lens 18, sample mounting unit 19, projection lens 21, STEM (Scanning Transmission Electron Microscope) detector 22, CCD camera (effective probe imaging unit) 23, And an EELS (Electron Energy Loss Spectroscopy) detector 24.

  The electron gun 11 accelerates electrons with an acceleration voltage corresponding to a signal from the control unit 10 and outputs the electrons as an electron beam. Below the electron gun 11, multiple stages (two stages in FIG. 1) of converging lenses 12a and 12b are arranged. These converging lenses 12 a and 12 b converge the electron beam output from the electron gun 11 to a desired size in accordance with a signal from the control unit 10.

  A converging lens stop 13 is disposed below the converging lenses 12a and 12b. Since the electron beams converged by the converging lenses 12a and 12b have an unnecessary spread portion, the unnecessary spread portion is cut by the convergent lens stop 13.

  A scanning coil 15 is disposed below the convergent lens stop 13. The scanning coil 15 refracts the electron beam according to the signal from the control unit 10 so that the electron beam probe scans the surface of the sample 20 mounted on the sample mounting unit 19.

  Below the scanning coil 15, an EDS detector (measuring instrument) 17, an objective lens 18 and a sample mounting portion 19 are arranged. The sample 20 is mounted on the sample mounting unit 19, and the objective lens 18 refracts the electron beam so as to be focused on or near the surface of the sample 20 in accordance with a signal from the control unit 10. The EDS detector 17 detects the X-rays emitted from the sample 20 by the electron beam irradiation, and outputs a signal corresponding to the detection result to the control unit 10.

  A plurality of stages (only one stage is shown in FIG. 1) of projection lenses 22 is arranged below the sample mounting portion 19. In the present embodiment, two modes are prepared for the projection lens 22. One is a diffraction image mode (observation image acquisition mode) used during STEM image observation, and the other is a real image mode (effective probe imaging mode) used for imaging an effective probe of an electron beam. The change from the diffracted image mode to the real image mode and the change from the real image mode to the diffracted image mode are performed by switching the lens condition of the projection lens 22, that is, by changing the current supplied to the projection lens 22 by a signal from the control unit 10. Is done.

  Below the projection lens 22, a STEM detector 22, a CCD camera 23, and an EELS detector (measuring device) 24 are arranged.

  The STEM detector 22 includes a ring-shaped DF (Dark-field) detector that detects electrons scattered by the sample 20 at a large angle, and a BF (Bright-Field) detector that detects electrons transmitted through the sample 20. have. The control unit 10 processes the signal output from the STEM detector 22 to create a bright field STEM image or a dark field STEM image. In the present embodiment, the STEM detector 22 is controlled by the control unit 10 and can be moved to a position outside the electron beam passage area.

  The CCD camera 23 is used for photographing an effective probe of an electron beam. When the projection lens 22 is set to the real image mode, an electron beam forms an image at the position of the CCD camera 23, and the data of the effective shape and size of the electron beam probe and the electron beam intensity distribution can be acquired. The CCD camera 23 is also controlled by the control unit 10 and can be moved to a position outside the electron beam passage area. Details of the effective probe will be described later. Instead of the CCD camera 23, data of an effective probe shape, size, and electron beam intensity distribution of an electron beam may be acquired using a TV camera, an imaging plate, a photosensitive film, or the like.

  The EELS detector 24 is used to measure the energy loss spectrum of the electron beam that has passed through the sample 20.

  FIG. 2A is a conceptual diagram showing a STEM-EELS spectrum imaging method using an EELS detector. Here, 22a indicates a DF detector (STEM detector). In FIG. 2A, the sample 20 is divided into a plurality of rectangular parallelepipeds, but one rectangular parallelepiped schematically shows one pixel (also referred to as an analysis target position).

  The sample 20 is irradiated with an electron beam (electron beam probe) at an angle (electron beam incident half angle) a. The electron beam irradiated on the sample 20 interacts with atoms in the sample 20 when traveling through the sample 20 in the thickness direction, and as a result, electrons are scattered or X-rays are generated. The DF detector 22a detects an electron beam (high angle scattered electrons or heat diffuse scattered electrons) scattered by the sample 20 at a large angle, and the EELS detector 24 transmits an electron beam (before the sample is incident). (Transmission electron beam in the same direction as the electron beam).

  For example, the control unit 19 generates a STEM image from a signal output from the DF detector 22a and acquires an EELS spectrum (electron beam energy loss spectrum) from the signal output from the EELS detector 24.

  FIG. 2B is a diagram illustrating an example of an EELS spectrum obtained from the output of the EELS detector 24, with energy on the horizontal axis and intensity (count number) on the vertical axis. As shown in FIG. 2B, an EELS spectrum corresponding to the sample position through which the electron beam has been transmitted is obtained from the output of the EELS detector 24. In practice, since the EELS spectrum is acquired while scanning the electron beam along the surface of the sample 20, as shown schematically in FIG. 3, a continuous EELS spectrum is obtained along the scanning direction. FIG. 3 shows an example in which the electron probe is scanned in the y direction.

  When such a continuous multipoint analysis is performed, if the size of the pixel is smaller than the probe size of the electron beam, a part of the electron beam is also irradiated to adjacent pixels. For this reason, the information output from the DF detector 22a and the EELS detector 24 includes information on adjacent pixels.

  4A and 4B are schematic diagrams showing the concept of continuous multipoint analysis. As shown in FIGS. 4A and 4B, in continuous multi-point analysis, X-rays emitted from the sample 20 or electrons transmitted through the sample are scanned while scanning the electron beam probe along the surface of the sample 20. The line is detected to obtain an electron microscope image, and analysis (elemental analysis or the like) is performed for each pixel (analysis target position). When the pixel size is smaller than the probe size of the electron beam, information obtained from each pixel includes information on adjacent pixels.

  FIGS. 5A to 5C are diagrams showing the influence of the probe size in a sample in which two kinds of materials are arranged in contact with each other. Here, as shown in the plan view on the left of FIG. 5A and the cross-sectional view on the right, the composition of a sample in which different materials A and B are arranged in contact with each other is examined. In this case, as shown in FIG. 5B, the electron beam probe is scanned along the surface of the sample, and the X-ray or electron beam energy loss spectrum is detected by the EDS detector 17 or the EELS detector 24. The composition is analyzed for each pixel (analysis target position). In addition, the left figure of FIG.5 (b) is a model top view which shows the locus | trajectory of the electron beam probe which scans a sample surface, and the right figure is the model side view similarly.

  If the probe size of the electron beam is larger than the pixel size, it is as if the material A and the material B are mixed in the vicinity of the contact position between the material A and the material B as shown in FIG. Information is obtained. The same applies to the measurement of the line profile, and the profile of the contact position between the materials A and B is blurred due to the overlap of the electron beam probes. 5C is a plan view schematically showing the distribution state of the materials A and B obtained by the analysis, and the right figure schematically shows the distribution state of the materials A and B obtained by the analysis. It is a graph to show.

  FIG. 6 shows the shape (intensity distribution) of the electron beam probe obtained by the simulation calculation, with the horizontal axis representing the position (distance from the center of the electron beam probe) and the vertical axis representing the intensity (relative intensity). FIG. FIGS. 7A to 7C are views showing the shape of the electron beam probe in a three-dimensional manner. The shape of the electron beam probe depends on the electron beam incident conditions. Here, the general conditions used in STEM, that is, the acceleration voltage is 200 kV, the electron beam incident half angle a is 12 mrad, the spherical aberration coefficient (Cs) is 1.0 mm, the chromatic aberration coefficient (Cc) is 1.0 mm, The probe shape when the focus shift amount (Δf) is −50 nm is shown. In calculating the effective probe size, the sample was made of silicon (Si) single crystal having a thickness of 30 nm.

  The observation probe used for observing the sample has a small probe diameter of, for example, 0.15 nm as shown in FIG. 6 and FIG. However, in order to obtain this probe diameter, it is necessary to reduce the electron beam intensity, and when performing analysis using EDS or EELS, the spectrum intensity is not sufficient and a good analysis result cannot be obtained. Therefore, when performing analysis, as shown in FIGS. 6 and 7B, the probe diameter is increased to, for example, 0.4 nm, and the current amount is increased instead of sacrificing the spatial resolution.

  The probe diameter of the electron beam expands by interacting with atoms in the sample when the electron beam passes through the sample. Under the conditions described above, when an electron beam probe having a diameter of 0.4 nm is irradiated onto a sample (a silicon single crystal having a thickness of 30 nm), the diameter of the electron beam probe expands to about 1.2 nm in the sample (FIGS. 6 and 6). 7 (c)), which is about three times that at the time of incidence. In this embodiment, the electron beam probe that spreads in the sample is called an effective probe. The spread of the electron beam probe in the sample depends on the composition and thickness of the sample. The effective probe size is represented by a convolution of the probe function and the interaction parameter, and has an intensity distribution with the center of the electron beam as a maximum value.

  8A and 8B are diagrams showing an outline of the analysis method according to the present embodiment. In FIGS. 8A and 8B, rectangles indicate respective pixels, and circles in FIG. 8A indicate effective probe diameters. The pixel size is, for example, 0.8 nm × 0.8 nm, and the effective probe diameter is, for example, 1.2 nm.

When the effective probe size is larger than the pixel size, even if the electron beam is irradiated to the pixel A, the pixels B to I around the pixel A are also irradiated with the electron beam. Here, the intensity of the electron beam irradiated to each pixel A to I I _Aa, I _Ab, and ... I _Ai. However, _assuming that the _total electron beam intensity is I _total , I _total = I _Aa + I _Ab + I _Ac + I _Ad + I _Ae + I _Af + I _Ag + I _Ah + I _Ai , and this value is when any electron beam is irradiated. Suppose there is no change. Further, as can be seen from FIG. 8A, I _Ab = I _Ac = I _Ad = I _Ae and I _Af = I _Ag = I _Ah = I _Ai .

The intensities of these electron beams I _Aa , I _Ab ,..., I _Ai are obtained by calculation from, for example, the simulation results shown in FIGS. 5 and 6 or the image of the electron beam probe (effective probe) acquired by the CCD camera 23. be able to.

Measurements at the position of each pixel A to I (e.g., EELS measurements of the spectrum) of A _exp, B _exp, ..., and I _exp. In this case, the true measured value A _calc of the pixel A is expressed by the following equation (1).

全ての画素において測定を行い、各画素毎に（１）式のような関係式をたてて連立方程式とする。この場合、各画素において隣接する画素の測定値が常に異なる場合は解を得ることができない。しかし、例えば図５に示すように測定値が同一になる画素が多数連続する場合は連立方程式を解くことが可能になり、各画素の真の測定値、すなわち各画素毎に他の画素からの影響を除いた測定値を得ることができる。

Measurement is performed for all pixels, and a relational expression such as the expression (1) is established for each pixel to be a simultaneous equation. In this case, a solution cannot be obtained if the measured values of adjacent pixels are always different in each pixel. However, for example, as shown in FIG. 5, when a large number of pixels having the same measurement value are consecutive, it is possible to solve the simultaneous equations, and the true measurement value of each pixel, that is, for each pixel, from other pixels. The measurement value excluding the influence can be obtained.

  In the above example, the case where the shape of the electron beam probe is a perfect circle has been described. However, even when the shape of the electron beam probe is not a perfect circle, a true measurement value can be obtained by the same calculation. In the above example, the case where the electron beam is simultaneously irradiated to the eight pixels (pixels B to I) when the pixel A is irradiated with the electron beam has been described. Even if the number is other than 8, a true measurement value can be obtained by the same calculation.

  FIG. 9 is a flowchart showing an analysis method according to the present embodiment. Note that FIG. 1 is also referred to in the following description.

  First, in step S11, observation conditions are set. That is, the data of the sample to be observed is input and the number of pixels and the pixel size are set.

  Next, the process proceeds to step S <b> 12 and the sample 20 is mounted on the sample stage 19. Thereafter, in step S13, the magnification is adjusted.

  Next, the effective probe shape, size, and electron beam intensity distribution are measured. Specifically, in step S14, the STEM detector 22 is retracted outside the electron beam passage area, and the CCD camera 23 is placed in the electron beam passage area. Then, the projection lens 21 is set to the real image mode. Thereafter, the process proceeds to step S15, the electron gun 11 is operated, and the sample 20 is irradiated with an electron beam.

  The electron beam transmitted through the sample 20 is imaged at the position of the CCD camera 23 by the projection lens 21, and an image of an effective probe as shown in FIG. 10 is taken by the CCD camera 23, for example. An image captured by the CCD camera 23 is transmitted to the control unit 10, and the control unit 10 obtains an effective probe shape, size, and electron beam intensity distribution from the image. Data regarding these effective probes is stored in the control unit 10.

  In order to measure the size of the effective probe, it is necessary to calibrate the scale of the electron microscope image in advance using a single crystal with a known lattice spacing such as gold (Au). It is. Instead of actually measuring the effective probe shape, size, and electron beam intensity distribution by the CCD camera 23, data of the effective probe shape, size, and electron beam intensity distribution may be obtained by simulation calculation.

  Next, in step S16, the projection lens 21 is set to the diffraction image mode. Further, the CCD camera 23 is retracted from the electron beam irradiation area, and the STEM detector 22 (DF detector 22a) is arranged in the electron beam irradiation area. The other conditions are the same as those for effective probe measurement.

  Next, in step S17, a STEM image is acquired and an EELS spectrum is measured. That is, the electron gun 11 is operated to irradiate the sample 20 with an electron beam, and the scanning coil 15 is operated to scan the electron beam along the surface of the sample. The control unit 10 generates an STEM image from the signal output from the STEM detector 22 and obtains an EELS spectrum from the signal output from the EELS detector 24.

  Next, in step S18, the control unit 10 uses the pixel size data and the effective probe data, performs the calculation shown in the equation (1), and analyzes the observation image intensity and the EELS spectrum for each pixel. calculate. In this way, a measurement value excluding the influence of other pixels can be obtained for each pixel, and analysis with high resolution can be performed. Thereby, for example, an accurate elemental composition image or physical property value distribution image can be obtained.

  In the above-described embodiment, the scanning transmission electron microscope has been described. However, the technique disclosed above can be applied to an ion microscope using an ion beam of hydrogen or helium instead of an electron beam.

  Hereinafter, various aspects of the present invention will be collectively described as supplementary notes.

(Additional remark 1) In the analysis method of the charged particle microscope which analyzes the sample by scanning the focused charged particle beam along the surface of the sample,
Obtaining data of the shape and size of the charged particle beam spread in the sample and the intensity distribution of the charged particles;
Scanning the charged particle beam along the surface of the sample while irradiating the sample with the charged particle beam, and measuring with a measuring instrument a phenomenon that occurs with irradiation of the charged particle beam for each analysis target position; ,
From the data of the shape and size of the charged particle beam spread in the sample and the intensity distribution of the charged particles, the charged particle dose irradiated to the analysis target position and the charged particle dose irradiated to the surroundings for each analysis target position And performing an operation of eliminating the influence around the analysis target position on the measurement value obtained by the measuring instrument based on the result.

  (Additional remark 2) The analysis method of Additional remark 1 characterized by the magnitude | size of the charged particle beam which spread in the said sample larger than the magnitude | size of the said analysis target position.

  (Additional remark 3) The said charged particle beam is an electron beam, The analysis method of Additional remark 1 or 2 characterized by the above-mentioned.

  (Additional remark 4) Additional charge 1 thru | or 3 characterized by obtaining the data of the shape and magnitude | size of the charged particle beam which spread | diffused in the said sample, and the intensity distribution of a charged particle by imaging | photography the charged particle beam which permeate | transmitted the said sample. The analysis method according to any one of the above.

  (Appendix 5) The analysis according to any one of appendices 1 to 3, wherein the data of the shape and size of the charged particle beam spread in the sample and the intensity distribution of the charged particle are obtained by simulation calculation. Method.

(Supplementary Note 6) In the calculation, A _calc is a measurement value excluding the influence of the surroundings at the analysis target position, and I _A is the intensity of the charged particle beam irradiated to the analysis target position. When the intensity of the charged particle beam irradiated to the periphery is I _B , the measured value at the analysis target position is A _exp, and the measurement value around the analysis target position is B _exp , A _calc = A _exp × I _a -B _exp × analysis method according to any one of appendices 1 to 5, characterized by being represented by I _B.

(Appendix 7) a charged particle source that emits a charged particle beam;
A converging lens for converging the charged particle beam on the sample;
A scanning coil for scanning the charged particle beam along the surface of the sample;
A projection lens disposed on the opposite side of the charged particle source with respect to the sample and capable of switching between an effective probe imaging mode and an observation image acquisition mode;
An effective probe imaging unit configured to image an effective probe composed of the charged particle beam spread in the sample when the projection lens is in the effective probe imaging mode;
An observation image acquisition unit that acquires an observation image of the sample when the projection lens is in the observation image acquisition mode;
A measuring instrument for measuring a phenomenon that occurs with irradiation of the charged particle beam from an analysis target position of the sample when the projection lens is in the observation image acquisition mode;
While controlling the charged particle beam source, the converging lens, the scanning coil, and the projection lens, data of an effective probe imaged by the effective probe imaging unit and observation image data acquired by the observation image acquisition unit And a control unit to which the measured value obtained by the measuring instrument is input,
The control unit calculates a charged particle dose irradiated to the analysis target position and a charged particle dose irradiated to the periphery thereof from the data of the effective probe, and acquired by the observation image acquisition unit based on the result A charged particle microscope characterized by performing an operation to eliminate the influence of the surrounding of the analysis target position on the data of the observed image or the measurement value obtained by the measuring device.

  (Appendix 8) The charged particle microscope according to appendix 7, wherein the charged particle beam is an electron beam.

  (Supplementary note 9) The charged particle microscope according to supplementary note 7 or 8, wherein the effective probe imaging unit is arranged at a position outside a passing region of the charged particle beam in the observation image acquisition mode.

(Supplementary Note 10) In the calculation, the measurement value excluding the influence of the surroundings at the analysis target position is set as A _calc , the intensity of the charged particle beam irradiated to the analysis target position is set as I _A , and the analysis target position When the intensity of the charged particle beam irradiated to the periphery is I _B , the measured value at the analysis target position is A _exp, and the measurement value around the analysis target position is B _exp , A _calc = A _exp × I _a -B _exp × charged particle microscope according to any one of appendices 7 to 9, characterized by being represented by I _B.

  DESCRIPTION OF SYMBOLS 10 ... Control part, 11 ... Electron gun, 12a, 12b ... Convergent lens, 13 ... Convergent lens aperture, 15 ... Scanning coil, 17 ... EDS detector, 18 ... Objective lens, 19 ... Sample mounting part, 20 ... Sample, 21 Projection lens, 22 STEM detector, 23 CCD camera, 24 EELS detector.

Claims (6)

In the analysis method of the charged particle microscope that analyzes the sample by scanning the focused charged particle beam along the surface of the sample,
Obtaining data of the shape and size of the charged particle beam spread in the sample and the intensity distribution of the charged particles;
Scanning the charged particle beam along the surface of the sample while irradiating the sample with the charged particle beam, and measuring with a measuring instrument a phenomenon that occurs with irradiation of the charged particle beam for each analysis target position; ,
From the data of the shape and size of the charged particle beam spread in the sample and the intensity distribution of the charged particles, the charged particle dose irradiated to the analysis target position and the charged particle dose irradiated to the surroundings for each analysis target position And performing an operation of eliminating the influence around the analysis target position on the measurement value obtained by the measuring instrument based on the result.   The analysis method according to claim 1, wherein the size of the charged particle beam spreading in the sample is larger than the size of the analysis target position.   3. The data of the shape and size of the charged particle beam spread in the sample and the intensity distribution of the charged particle are obtained by photographing the charged particle beam that has passed through the sample. 4. analysis method.   The analysis method according to claim 1 or 2, wherein the data of the shape and size of the charged particle beam spreading in the sample and the intensity distribution of the charged particle are obtained by simulation calculation. In the calculation, A _calc is a measurement value excluding the influence of the surroundings at the analysis target position, and I _A is the intensity of the charged particle beam irradiated to the analysis target position. A _calc = A _exp × I _A where I _B is the intensity of the charged particle beam, I _exp is the measured value at the analysis target position, and B _exp is the measurement value around the analysis target position. the method of analysis according to any one of claims 1 to 4, characterized by being represented by -B _exp × I _B. A charged particle source that emits a charged particle beam;
A converging lens for converging the charged particle beam on the sample;
A scanning coil for scanning the charged particle beam along the surface of the sample;
A projection lens disposed on the opposite side of the charged particle source with respect to the sample and capable of switching between an effective probe imaging mode and an observation image acquisition mode;
An effective probe imaging unit configured to image an effective probe composed of the charged particle beam spread in the sample when the projection lens is in the effective probe imaging mode;
An observation image acquisition unit that acquires an observation image of the sample when the projection lens is in the observation image acquisition mode;
A measuring instrument for measuring a phenomenon that occurs with irradiation of the charged particle beam from an analysis target position of the sample when the projection lens is in the observation image acquisition mode;
While controlling the charged particle beam source, the converging lens, the scanning coil, and the projection lens, data of an effective probe imaged by the effective probe imaging unit and observation image data acquired by the observation image acquisition unit And a control unit to which the measured value obtained by the measuring instrument is input,
The control unit calculates a charged particle dose irradiated to the analysis target position and a charged particle dose irradiated to the periphery thereof from the data of the effective probe, and acquired by the observation image acquisition unit based on the result A charged particle microscope characterized by performing an operation to eliminate the influence of the surrounding of the analysis target position on the data of the observed image or the measurement value obtained by the measuring device.

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