JP2007192741A - Element analysis method and element analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an element analysis method which enables an easy and simple correction of the positional shift in the analyzing target region, produced by making a sample inclined. <P>SOLUTION: The element analysis method includes a process for placing the sample on a sample stage, capable of being inclined at an arbitrary angle and of being moved in an arbitrary direction; a process for scanning the surface of the sample by an electron beam, while holding the sample on the sample stage to acquire the electron microscope image of the sample; a process for making the center point of the analyzing target region of the sample coincide with a predetermined measuring position by using the electron microscope image, while moving the sample, a process for inclining the sample at a predetermined angle, a process for correcting the positional shift of the sample so that the center point of analyzing target region, after inclination, coincides with the measuring position and a process for irradiating the sample with the electron beam and detecting the characteristic X rays emitted from the analyzing target region and analyzing the element of the substance existing in the vicinity of the surface of the analyzing target region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an elemental analysis method and an elemental analysis apparatus, and more particularly to an elemental analysis method and an elemental analysis apparatus that analyze elements of a sample by analyzing characteristic X-rays emitted from the sample irradiated with an electron beam.

Electron beam probe micro X-rays that irradiate a sample with an electron beam and detect characteristic X-rays excited from the irradiated micro region or surface with an X-ray detector as a technique for performing elemental analysis of a micro region or surface of the sample An analyzer (EPMA) is known.
EPMA utilizes the fact that when a sample is irradiated with an electron beam, each element existing in the irradiated region emits characteristic X-rays having specific energy and wavelength.
By analyzing the energy spectrum and wavelength distribution of characteristic X-rays excited by an electron beam, the elements present in the irradiated region can be known.

However, in the conventional EPMA, for example, it is difficult to analyze a minute object existing on the sample surface or a thin layer element having a thickness of less than a micrometer on the sample surface.
This is because the characteristic X-rays emitted from the sample include characteristic X-rays emitted from both the inside of the sample and the minute object or thin layer on the sample surface, and the X-ray intensity emitted from the inside of the sample is This is because it is stronger than the characteristic X-rays emitted from the minute object or thin layer on the sample surface, so that only the characteristic X-rays emitted from the minute object or thin layer cannot be selectively extracted and analyzed.

In this regard, a method of exciting characteristic X-rays only from the vicinity of the sample surface by irradiating a low energy (low acceleration) electron beam to reduce the depth of penetration of the electron beam into the sample can be considered.
However, the use of a low-energy electron beam limits the elements that can be detected, and is not appropriate, for example, when the elements to be detected are unknown and all elements need to be detected.

Since fine particles (foreign matter) such as silicon existing on a semiconductor wafer adversely affect the yield of semiconductor devices, the composition and origin of the fine particles must be clarified to prevent the generation of fine particles.
If the composition of the fine particles is to be analyzed, the fine X-rays excited by the electron beam are analyzed by irradiating the fine particles with an electron beam with an electron beam probe or the like. Therefore, composition analysis of only the fine particles was difficult.

As a solution to such a problem, a new analysis method by oblique emission X-ray measurement (hereinafter referred to as “oblique emission EPMA”) has been proposed.
This oblique emission EPMA tilts the sample in an angle range in which characteristic X-rays emitted from the inside of the sample are not emitted from the sample surface due to the total reflection phenomenon with respect to the electron beam irradiation direction, and from fine particles or thin layers existing on the sample surface. Only emitted characteristic X-rays are detected and analyzed (see, for example, Patent Document 1, Patent Document 2, and Non-Patent Document 1).

JP 2001-208708 A JP 2002-286661 A K. Tsuji et al. , Anal. Chem. 71 (1999): 2497-2501

At present, there is no commercially available product as the oblique emission EPMA apparatus, but the measurement by the oblique emission EPMA is possible relatively easily using the commercially available EPMA apparatus.
In the oblique emission EPMA, it is important to control the angle (characteristic X-ray emission angle or extraction angle) of the characteristic X-rays emitted from the fine particles or thin layer on the sample surface and incident on the X-ray detector with respect to the sample surface, For this purpose, a method of tilting the sample holder, an X-ray detector (energy-dispersive X-ray detector: EDX) and a wavelength-dispersive X-ray detector: A method of moving WDX)) and a method of moving the sample stage up and down are considered.

Each method has advantages and disadvantages. In a commercially available EPMA or SEM-EDX apparatus, since the electron source and the X-ray detector are fixed to the vacuum chamber, a method of moving the X-ray detector cannot be adopted.
As a method of controlling the emission angle in a commercially available EPMA apparatus, a method of tilting the sample stage or a method of moving the sample stage up and down is easy.

  In the method of moving the sample stage up and down, the range of the X-ray extraction angle is limited. On the other hand, the method of tilting the sample stage can realize a wide range of X-ray extraction angles, and is suitable for oblique emission EPMA analysis.

However, in the method of tilting the sample stage, the position (X and Y) and focus (height Z) on the plane of the analysis target region and the contrast of the electron microscope image fluctuate during tilt movement. It is necessary to make adjustments.
If the center point of the analysis target area exactly coincides with the tilt axis, even if the emission angle is changed, that is, the position of the analysis target area on the plane where the electron beam is irradiated even if the sample is tilted (X and Y) and focus (height Z) do not change. However, it is actually very difficult to match the tilt axis with the center point of the analysis target area. As described above, the positional shift of the analysis target region due to the tilt movement is very problematic in the local analysis and the minute inclusion analysis.

  In the oblique emission EPMA, the work for correcting the position shift of the analysis target region caused by the tilt movement is not only inefficient but also inefficient, and may cause deterioration or deterioration of the sample surface due to long-time electron beam irradiation. There is also.

  The present invention has been made in view of the above circumstances, and provides an elemental analysis method and an elemental analysis apparatus capable of easily and simply correcting a positional shift of an analysis target region caused by tilting a sample. It is.

  The present invention includes a step of placing a sample on a sample stage that can be inclined at an arbitrary angle and movable in an arbitrary direction, and an electron beam is scanned on the surface of the sample while holding the sample on the stage. A step of obtaining an electron microscope image, a step of aligning the center point of the analysis target region of the sample with a predetermined measurement position using the electron microscope image while moving the sample, a step of tilting the sample at a predetermined angle, The step of correcting the positional deviation of the sample so that the center point of the subsequent region coincides with the measurement position, and the characteristic X-ray emitted from the analysis target region by irradiating the sample with an electron beam to detect the surface of the region And an element analyzing method including a step of analyzing an element of a substance existing in the vicinity.

  According to the present invention, the positional deviation of the center point of the analysis target region with respect to the predetermined measurement position caused by tilting the sample is matched with the measurement position in the step of correcting the positional deviation of the sample. Therefore, the correction of the position shift of the analysis target region is easily and easily performed.

The elemental analysis method according to the present invention includes a step of placing a sample on a sample stage that can be inclined at an arbitrary angle and movable in an arbitrary direction, and an electron beam is applied to the surface of the sample while holding the sample on the stage. Scanning to obtain an electron microscope image of the sample, moving the sample, using the electron microscope image to match the center point of the analysis target region of the sample with a predetermined measurement position, and tilting the sample to a predetermined angle A step of correcting the positional deviation of the sample so that the center point of the region after tilting coincides with the measurement position, and detecting characteristic X-rays emitted from the analysis target region by irradiating the sample with an electron beam The method includes a step of analyzing an element of a substance existing in the vicinity of the surface of the region.
Here, the substance existing near the surface of the analysis target region includes, for example, fine particles existing on the analysis target region, and a thin layer existing on the surface of the analysis target region.

In the elemental analysis method according to the present invention, the step of correcting the positional deviation of the sample may include a step of obtaining a horizontal positional deviation amount of the center point with respect to the predetermined measurement position by image recognition using a CCD camera.
According to such a configuration, since the amount of displacement in the horizontal direction (X direction and Y direction) of the center point with respect to the predetermined measurement position is obtained by image recognition by the CCD camera, highly accurate position correction can be performed easily and simply. It becomes like this.
When such a configuration is used, the process of obtaining the horizontal displacement amount at every fixed inclination angle, and correcting the obtained horizontal displacement amount, the sample reaches the final target inclination angle. It is preferable to repeat several times.

In the elemental analysis method according to the present invention, in the step of correcting the positional deviation of the sample, the correlation between the inclination angle of the specimen and the amount of horizontal positional deviation of the center point with respect to the predetermined measurement position is obtained in advance by image recognition using a CCD camera. The method may include a step of deriving a horizontal displacement amount to be corrected based on the correlation according to the inclination angle.
According to such a configuration, the correlation between the tilt angle of the sample and the amount of positional deviation in the horizontal direction (X direction and Y direction) of the center point with respect to the predetermined measurement position is obtained in advance, and correction is performed based on the correlation. Since the amount of horizontal displacement should be derived according to the tilt angle, there is no need to use an electron microscope image when actually correcting the position in the horizontal direction. It is possible to suppress deterioration and deterioration of

In the elemental analysis method according to the present invention, the step of correcting the positional deviation of the sample may include a step of correcting the position of the center point in the electron beam irradiation direction by image recognition by a CCD camera.
According to such a configuration, since the positional deviation of the center point in the height direction (Z direction) is corrected by image recognition by the CCD camera, highly accurate position correction can be performed easily and simply.

In the elemental analysis method according to the present invention, in the step of correcting the positional deviation of the sample, the correlation between the inclination angle of the specimen and the amount of positional deviation of the center point along the electron beam irradiation direction is obtained in advance by image recognition using a CCD camera. A step of deriving a positional deviation amount to be corrected along the irradiation direction of the electron beam based on the correlation and deriving according to the inclination angle may be included.
According to such a configuration, the correlation between the tilt angle of the sample and the amount of positional deviation in the height direction (Z direction) of the center point is obtained in advance, and the position in the height direction to be corrected based on the correlation Since the amount of deviation is derived according to the tilt angle, there is no need to use an electron microscope image when actually correcting the position of the sample in the height direction. It is possible to suppress deterioration and deterioration of the material.

The elemental analysis method according to the present invention may further include a step of correcting the contrast of the electron microscope image when correcting the position of the sample.
According to such a configuration, the contrast of the electron microscope image is corrected when correcting the position of the sample.
For this reason, when image recognition by a CCD camera is used for correction of positional deviation, the accuracy of image recognition is improved, and as a result, more accurate position correction can be performed.

Here, the step of correcting the contrast of the electron microscope image may include a step of correcting the contrast of the electron microscope image by image recognition using a CCD camera.
According to such a configuration, since the contrast of the electron microscope image is corrected by image recognition by the CCD camera, it is possible to correct the contrast with high accuracy.

Further, in the step of correcting the contrast of the electron microscope image, the correlation between the tilt angle of the sample and the change in the contrast of the electron microscope image is obtained in advance by image recognition using a CCD camera, and the contrast to be corrected based on the correlation. A step of deriving the value according to the inclination angle may be included.
According to such a configuration, the correlation between the tilt angle of the sample and the contrast change of the electron microscope image is obtained in advance by image recognition by the CCD camera, and the contrast value to be corrected based on the correlation is the tilt angle. Therefore, it is not necessary to use an electron microscope image when actually correcting the contrast, irradiation of the electron beam to the sample is suppressed, and alteration or deterioration of the sample surface is suppressed.

  From another viewpoint, the present invention can be tilted at an arbitrary angle and movable in an arbitrary direction, a driving unit for driving the sample stage, and a surface of the sample placed on the sample stage. In contrast, an electron beam scanning unit that scans an electron beam, a secondary electron detection unit that detects secondary electrons emitted from a sample that has been scanned with an electron beam, and secondary electrons detected by the secondary electron detection unit An imaging unit that captures an electron microscope image visualized based on the image, a control unit that controls the drive unit based on the captured electron microscope image and sets the sample at a predetermined position and tilt angle, and a set position and tilt There is also provided an elemental analysis apparatus including a characteristic X-ray detection unit that detects characteristic X-rays emitted from a sample irradiated with an electron beam at an angle.

  Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

Based on FIGS. 1-6, the elemental analysis method by the Example of this invention is demonstrated.
FIG. 1 is a schematic configuration diagram of an elemental analysis apparatus used in an elemental analysis method according to an embodiment.

The elemental analysis method according to the embodiment of the present invention is carried out using the elemental analysis apparatus shown in FIG.
An elemental analyzer (electron probe micro X-ray analyzer) 1 shown in FIG. 1 can be tilted at an arbitrary angle and movable in an arbitrary direction, and a drive unit 3 that drives the sample stage. And an electron beam scanning unit 5 that scans the surface of the sample 4 placed on the sample stage 2 with the electron beam E, and secondary electrons S emitted from the sample 4 that has been scanned with the electron beam E are detected. Secondary electron detection unit 6, display unit 7 for displaying an electron microscope image visualized based on secondary electrons S detected by secondary electron detection unit 6, and imaging unit for imaging the visualized electron microscope image 8, a storage unit 9 that stores an electron microscope image captured by the imaging unit 8 as image data, and a drive unit 3 based on the image data stored in the storage unit 9 to control the sample 4 at a predetermined position and tilt angle. Control unit 10 to be set to And a characteristic X-ray detector 11 for detecting the characteristic X-ray C emitted radiation from the sample 4 that has received the electron beam E in position and the tilt angle is.

The elemental analyzer 1 is mainly composed of a lens barrel 12 in which an electron beam scanning unit 5 is accommodated, a sample chamber 13 in which a sample stage 2 is accommodated, and a spectroscopic chamber 14 in which X-ray spectroscopy is performed.
The sample stage 2 accommodated in the sample chamber 13 includes an X-axis stage 2a, a Y-axis stage 2b, an inclined stage 2c, and a Z-axis stage 2d, and moves in the X-axis direction, the Y-axis direction, and the Z-axis direction. And can be inclined in any direction.
The X-axis stage 2a, Y-axis stage 2b, tilt stage 2c, and Z-axis stage 2d are each driven by a pulse motor (not shown) as the drive unit 3.
The sample 4 is set on the sample holder 15 and then carried onto the sample stage 2 from a sample inlet / outlet (not shown).

The electron beam scanning unit 5 accommodated in the lens barrel 12 is converged by an electron gun 16 that emits an electron beam E, a converging lens 17 that converges the electron beam E emitted from the electron gun 16, and a converging lens 17. It is mainly composed of a scanning coil 18 that scans the electron beam E and an electromagnetic objective lens 19 that narrows the electron beam E into an electron probe shape.
An optical objective lens 20 is disposed in the vicinity of the electromagnetic objective lens 19, and a sample image reflected by the optical reflecting mirror 21 is configured to enter an optical microscope 22 mounted in the sample chamber 13.
The optical microscope 22 is used for focus adjustment. The focus adjustment of the optical microscope 22 and the movement of the Z-axis stage 2d are interlocked, and adjustment is performed so that the image of the optical microscope 22 becomes clear. The height of the sample 4 is adjusted.

  The secondary electron detector 6 accommodated in the sample chamber 13 includes a secondary electron detector and an amplifier (not shown), and the display unit 7 includes an image processing device and a display panel (not shown). An electron microscope image formed based on the secondary electrons S captured by the container is displayed on the display unit 7.

An imaging unit 8 that captures an electron microscope image displayed on the display unit 7 is a CCD camera, and the electron microscope image captured by the CCD camera is stored as image data in a storage unit 9 as a storage medium.
The control unit 10 mainly includes an I / O port (not shown), a CPU, a ROM storing a control program, a RAM storing various setting conditions, and various driver circuits, and a plurality of image data stored in the storage unit 9. Are compared, the moving amount of the sample 4 accompanying the driving of the sample stage 2 is calculated, and the driving unit 3 is controlled based on the calculated moving amount.
The driving unit 3, the display unit 7, the imaging unit 8, the storage unit 9, and the electron beam scanning unit 5 are connected to the control unit 10 via the bus line 27 and perform a series of operations under the control of the control unit 10. Do.
Although not shown, the lens barrel 12, the sample chamber 13, and the spectroscopic chamber 14 are connected to a vacuum exhaust device, and the control unit 10 also controls the vacuum exhaust device.

The characteristic X-ray detector 11 includes an energy dispersive X-ray detector (EDX) 23 in which an incident port 23 a for the characteristic X-ray C projects into the sample chamber 13, and a wavelength dispersive X-ray detector housed in the spectroscopic chamber 14. (WDX) 24.
The energy dispersive X-ray detector 23 detects a characteristic X-ray C and generates a pulse current proportional to the energy of the characteristic X-ray, and a pulse current generated by the semiconductor detector. It mainly comprises a multi-channel wave analyzer (not shown) for sorting.
On the other hand, the wavelength dispersive X-ray detector 24 is stored in the spectroscopic chamber 14 and separates (spectroscopes) with X-rays having a specific wavelength. 26 mainly.

  Both EDX 23 and WDX 24 are connected to bus line 27, and data detected by EDX 23 and WDX 24 is processed by control unit 10, and an analysis result is displayed on display unit 7.

  Hereinafter, an elemental analysis method using such an elemental analyzer 1 will be described in detail based on a plurality of examples.

Example 1
In Example 1, first, the sample stage 2 is held in a horizontal state, the magnification is set to 10,000 times, and an electron microscope image of the sample 4 made of AlGaAs is obtained.
Next, the height of the surface of the sample 4 is adjusted by the optical microscope 22, and the contrast adjustment, focus adjustment, and stigma adjustment of the electron microscope image are further performed.
Next, an arbitrary analysis target region is selected from the electron microscope image, and the X-axis stage 2a and the Y-axis stage 2b are driven by the drive unit 3 under the control of the control unit 10, and the center point of the analysis target region is measured in a predetermined manner. Match the position (predetermined coordinates).

Next, the control unit 10 causes the imaging unit 8 to capture an electron microscope image, and causes the storage unit 9 to store the captured electron microscope image as image data.
Next, under the control of the control unit 10, the tilt stage 2 c is driven by the drive unit 3 to tilt the sample 4 by 35 °.
Next, the control unit 10 causes the imaging unit 8 to capture the electron microscope image after the sample 4 is tilted, and causes the storage unit 9 to store the captured electron microscope image as image data.

Next, the control unit 10 compares the electron microscope image with the sample 4 in a horizontal state with the electron microscope image after the sample 4 is tilted, and the X-axis direction of the analysis target region center point with respect to the predetermined measurement position and A positional deviation amount in the Y-axis direction is calculated.
Next, the control unit 10 instructs the drive unit 3 to perform a correction amount that cancels the calculated positional deviation amounts in the X-axis direction and the Y-axis direction. The drive unit 3 controls the X-axis stage 2a and the Y-axis stage 2b. Driven to match the center point of the analysis target region with a predetermined measurement position.

Next, the control unit 10 automatically varies the contrast value of the electron microscope image and causes the imaging unit 8 to continuously capture the electron microscope image. The contrast of the electron microscope image and the electron microscope in which the sample 4 is horizontal Stops the fluctuation of the contrast value when the contrast of the image matches.
In addition, it is judged based on the light quantity of an electron microscope image that the contrast corresponded. Further, this contrast correction step may be performed prior to the above-described step of correcting the positional deviation in the X-axis and Y-axis directions.

Next, the control unit 10 causes the drive unit 3 to drive the Z-axis stage 2d and causes the imaging unit 8 to continuously capture the electron microscope images, and when the center point of the analysis target area becomes the clearest image. The drive of the Z-axis stage 2d by the drive unit 3 is stopped.
Thereafter, the control unit 10 irradiates the sample 4 with the electron beam E from the electron gun 16, causes the energy dispersive X-ray detector to detect the characteristic X-ray C emitted from the analysis target region of the sample 4, and outputs the detection result as energy. It is displayed on the display unit 7 as a spectrum.

At this time, since the sample 4 is inclined as shown in FIG. 2, the characteristic X-ray C generated at a deep position inside the sample 4 is blocked by the slit due to refraction at the surface of the sample 4. Only the characteristic X-rays C emitted from the fine particles or the thin layer on 4 are detected from the sample 4.
As a result, the substance present near the surface of the analysis target region, that is, the fine particle or thin layer element existing near the surface of the analysis target region is analyzed. As a result of analysis, in Example 1, it was confirmed that the elements of the fine particles adhering on the surface of the analysis target region were C and Ag.

Example 2
In the second embodiment, the process of calculating the amount of positional deviation in the X-axis and Y-axis directions after the sample 4 is tilted in the first embodiment described above is modified.
In the second embodiment, the positional deviation amount (displacement of the X coordinate and the Y coordinate) of the center point of the analysis target region with respect to a predetermined measurement position at a plurality of inclination angles in the X axis direction and the Y axis direction is previously determined by the imaging unit 8 and the control unit. 10 is used for measurement and recording, and the correlation between the tilt angle of the sample 4 as shown in FIGS. 3 and 4 and the amount of displacement in the X-axis direction and Y-axis direction of the center point with respect to a predetermined measurement position is obtained. Find in advance.
In the step of actually correcting the positional deviation amount of the sample 4 in the X-axis direction and the Y-axis direction, the correction amount to be corrected by the control unit 10 based on the correlation obtained in advance without using the imaging unit 8. Is calculated according to the inclination angle, and the drive unit 3 is instructed to drive the X-axis stage 2a and the Y-axis stage 2b, thereby correcting the positional deviation in the X-axis and Y-axis directions.
Other steps are the same as those in the first embodiment.
According to such a method, since it is not necessary to obtain an electron microscope image in the step of correcting the positional deviation amount in the X-axis direction and the Y-axis direction, the irradiation of the electron beam E on the sample 4 can be suppressed, and the surface of the sample 4 It is possible to suppress deterioration and deterioration of the material.

Example 3
The third embodiment is a modification of the second embodiment described above.
In the third embodiment, the amount of displacement in the Z-axis direction (displacement of the Z coordinate) of the center point of the analysis target region with respect to a predetermined measurement position at a plurality of inclination angles is measured and recorded in advance using the imaging unit 8 and the control unit 10. In addition, the correlation between the tilt angle of the sample 4 as shown in FIG. 5 and the amount of displacement in the Z-axis direction of the center point with respect to the predetermined measurement position is obtained in advance.
Then, in the step of actually adjusting the focus, the correction amount to be corrected by the control unit 10 is calculated according to the inclination angle based on the correlation obtained in advance without using the imaging unit 8, and this is calculated as the drive unit. 3 is instructed to drive the Z-axis stage 2d to adjust the focus.
According to such a method, since it is not necessary to obtain an electron microscope image in the step of adjusting the focus, irradiation of the electron beam E to the sample 4 can be further suppressed.

Example 4
The fourth embodiment is a modification of the third embodiment described above.
In Example 4, the correlation between the tilt angle of the sample 4 and the change in contrast of the electron microscope image is measured and recorded in advance using the imaging unit 8 and the control unit 10 at a plurality of tilt angles. The correlation between the tilt angle of the sample 4 as shown and the contrast change of the electron microscope image is obtained in advance.
Then, in the step of actually correcting the contrast, the contrast value to be corrected by the control unit 10 is calculated according to the inclination angle based on the correlation obtained in advance without using the imaging unit 8, and the contrast is corrected. .
According to such a method, since it is not necessary to obtain an electron microscope image in the step of correcting the contrast, the irradiation of the electron beam E to the sample 4 can be suppressed to a necessary minimum.

It is a schematic block diagram of the elemental analysis apparatus used for the elemental analysis method by the Example of this invention. It is explanatory drawing which shows the state in which the sample was inclined in the elemental analysis apparatus shown by FIG. It is a graph which shows the correlation with the inclination-angle of a sample, and the positional offset amount of the center point with respect to a predetermined measurement position of the X-axis direction. It is a graph which shows the correlation with the inclination-angle of a sample, and the amount of position shift of the Y-axis direction of the center point with respect to a predetermined measurement position. It is a graph which shows the correlation with the inclination-angle of a sample, and the amount of position shift of the center point with respect to a predetermined measurement position in the Z-axis direction. It is a graph which shows the correlation with the inclination angle of a sample, and the change of the contrast of an electron microscope image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Elemental analyzer 2 ... Sample stage 2a ... X-axis stage 2b ... Y-axis stage 2c ... Inclination stage 2d ... Z-axis stage 3 ... Drive part 4 ... Sample 5 ... Electron beam scanning unit 6 ... Secondary electron detection unit 7 ... Display unit 8 ... Imaging unit 9 ... Storage unit 10 ... Control unit 11 ... Characteristic X-ray detection Part 12 ... Tube 13 ... Sample chamber 14 ... Spectroscopic chamber 15 ... Sample holder 16 ... Electron gun 17 ... Converging lens 18 ... Scanning coil 19 ... Electromagnetic objective lens DESCRIPTION OF SYMBOLS 20 ... Optical objective lens 21 ... Optical reflector 22 ... Optical microscope 23 ... Energy dispersive X-ray detector (EDX)
23a ... Entrance 24 ... Wavelength dispersive X-ray detector (WDX)
25 ... Spectral crystal 26 ... X-ray detector 27 ... Bus line C ... Characteristic X-ray E ... Electron beam S ... Secondary electron

Claims (9)

  A step of placing the sample on a sample stage that can be inclined at an arbitrary angle and movable in an arbitrary direction, and an electron microscope image of the sample is scanned by scanning an electron beam on the surface of the sample while holding the sample on the stage. A step of obtaining the center point of the analysis target region of the sample with a predetermined measurement position using an electron microscope image while moving the sample, a step of tilting the sample at a predetermined angle, and the region after tilting A step of correcting the misalignment of the sample so that the center point of the sample coincides with the measurement position, and a characteristic X-ray emitted from the analysis target region by irradiating the sample with an electron beam and present near the surface of the region Analyzing the element of the substance.   The element analysis method according to claim 1, wherein the step of correcting the positional deviation of the sample includes a step of obtaining a horizontal positional deviation amount of the center point with respect to a predetermined measurement position by image recognition using a CCD camera.   In the step of correcting the positional deviation of the sample, the correlation between the inclination angle of the specimen and the horizontal positional deviation amount of the center point with respect to the predetermined measurement position is obtained in advance by image recognition using a CCD camera, and the correction is performed based on the correlation. The elemental analysis method according to claim 1, further comprising a step of deriving an amount of positional shift to be made according to an inclination angle.   The element analysis method according to claim 1, wherein the step of correcting the positional deviation of the sample includes a step of correcting the position of the center point in the electron beam irradiation direction by image recognition by a CCD camera.   In the step of correcting the positional deviation of the sample, the correlation between the inclination angle of the specimen and the amount of positional deviation of the center point along the electron beam irradiation direction is obtained in advance by image recognition using a CCD camera, and based on the correlation. The elemental analysis method according to claim 1, further comprising a step of deriving a positional deviation amount to be corrected along the irradiation direction of the electron beam according to the inclination angle.   The elemental analysis method according to claim 1, further comprising a step of correcting the contrast of the electron microscope image when correcting the position of the sample.   The element analysis method according to claim 6, wherein the step of correcting the contrast of the electron microscope image includes a step of correcting the contrast of the electron microscope image by image recognition using a CCD camera.   In the step of correcting the contrast of the electron microscope image, the correlation between the tilt angle of the sample and the change in the contrast of the electron microscope image is obtained in advance by image recognition using a CCD camera, and the contrast value to be corrected is determined based on the correlation. The elemental analysis method according to claim 6, comprising a step of deriving according to the inclination angle.   A sample stage that can be tilted at an arbitrary angle and movable in an arbitrary direction, a drive unit that drives the sample stage, and an electron beam scan that scans the surface of the sample placed on the sample stage. An electron microscope image visualized based on the secondary electrons detected by the secondary electron detector, and a secondary electron detector that detects secondary electrons emitted from the sample that has been scanned with the electron beam An imaging unit that controls the drive unit based on the captured electron microscope image to set the sample at a predetermined position and tilt angle, and a sample that has been irradiated with an electron beam at the set position and tilt angle An elemental analysis apparatus comprising: a characteristic X-ray detection unit that detects characteristic X-rays emitted from

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