TW201802859A - Method for cross-section processing and observation and apparatus therefor - Google Patents

Abstract

Disclosed herein is a method for cross-section processing and observation, and apparatus therefore, the method including: performing a position information obtaining process of observing the entirety of a sample by using an optical microscope or an electron microscope, and of obtaining three-dimensional position coordinate information of a particular observation target object included in the sample; performing a cross-section processing process of irradiating a particular region in which the object is present by using a focused ion beam based on the information, and of exposing a cross section of the region; performing a cross-section image obtaining process of irradiating the cross section by using an electron beam, and of obtaining a cross-section image of a predetermined size region including the object; and performing a three-dimensional image obtaining process of repeating the cross-section processing process and the cross-section image obtaining process at predetermined intervals in a predetermined direction, and of obtaining a three-dimensional image from obtained multiple cross-section images.

Description

Section processing observation method, section processing observation device

The present invention relates to a sectional processing observation method and a sectional processing observation device for obtaining a cross-sectional image by irradiating an electron beam toward a specific portion of a sample formed by a focused ion beam including a specific observation object, and constructing a three-dimensional stereoscopic image of the specific observation object.

For example, as one of methods for analyzing the internal structure of a sample such as a semiconductor element or performing stereoscopic observation, a cross-section observation method (for example, Patent Document 1) is known: using a focused ion beam (Focused Ion Beam); FIB) A composite charged particle beam device with an electron beam (Electron Beam; EB) lens barrel, repeating the process of forming sections using FIB and scanning electron microscopy (SEM) scanning the sections with EB Obtain cross-sectional images of multiple object samples, and then overlay these multiple cross-sectional images to construct a three-dimensional image of the sample.

In this section processing observation method, a section forming process using FIB is called a cut, and a section observation using EB is called a see. Repeated cutting and a series of methods for constructing a three-dimensional image have been performed. Knowing & Seeing. In this method, the three-dimensional shape of the object sample can be viewed from various directions based on the constructed three-dimensional stereoscopic image. Furthermore, there is an advantage that an arbitrary cross-section of an article sample can be reproduced, which is not available in other methods.

As a specific example, the sample is irradiated with FIB to perform an etching process to expose the cross section of the sample. Next, SEM observation was performed on the exposed cross section to obtain a cross section image. Next, after the etching process is performed again to expose the next cross section, a second cross section image is obtained by SEM observation. In this manner, the etching process and the SEM observation were repeated in an arbitrary direction of the sample to obtain a plurality of cross-sectional images. In addition, a method of constructing a three-dimensional stereoscopic image that transmits the inside of a sample by overlapping a plurality of cross-sectional images obtained at the end is known.

Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Laid-Open No. 2008-270073.

However, when the sample of the observation object is a biological sample such as a cell, it is fixed as an embedding block by an embedding agent such as paraffin. In the case where such a biological sample is used to process an observation object, a high-resolution three-dimensional stereo image can be selectively constructed only for a specific observation object such as minute cells dispersed in the object sample. When an EB observes an embedded block, it observes only the surface layer of the embedded block, and cannot specifically designate the location of a specific observation object such as cells dispersed in the object sample (embedded block). Therefore, when the above-mentioned cutting & viewing method is applied to a sample of a specific observation object, the processing area using FIB needs to be set as the entire sample, and the entire sample is used as the object to repeatedly cut and look, so that the specific observation object appears in the In the processed section, there is a problem that a large amount of time is required for observation.

In addition, when such a sample is cut and viewed repeatedly as an object, the number of cross-sectional images generated is also huge. Therefore, in order to generate a three-dimensional stereoscopic image of a specific observation object, it is also inefficient and expensive to construct a three-dimensional stereoscopic image by extracting only a cross-sectional image of a part containing a specific observation object from such a large number of cross-sectional images. The order of time. In particular, in the case of a biological sample, many of them have a small size of a specific observation object. In order to make it a high-precision three-dimensional stereoscopic image, it is necessary to make the processing interval using FIB as narrow as possible and repeat a wide field of view. SEM observation. Therefore, a large number of cross-sectional images are obtained in the entire sample. However, it is not necessary to include cross-sectional images other than a specific part of a specific observation object, and there are also problems in the image processing device for processing or temporarily storing such unnecessary cross-sectional images. The problem of excessive load.

Furthermore, when a specific observation object is not included in the sample, there is also a problem in the observation of the entire sample that requires a long period of time to observe and cut the entire sample, which is useless.

The present invention has been made in view of the foregoing circumstances, and an object thereof The object is to provide a cross-section processing observation method and a cross-section processing observation device that can quickly and efficiently observe only a specific portion including a specific observation object included in a sample and can easily generate a three-dimensional stereoscopic image of the specific observation object.

In order to solve the above-mentioned problems, several aspects of the present invention provide the following cross-section observation methods and cross-section observation devices.

That is, the cross-section observation method of the present invention is characterized by having a position information acquisition step, observing the entire sample of the observation object using an optical microscope or an electron microscope, and obtaining the specific observation object included in the sample in the sample. The approximate three-dimensional position coordinate information within the profile; the section processing step, based on the three-dimensional position coordinate information, irradiates a focused ion beam toward a specific part where the specific observation object exists in the sample, so that the cross section of the specific part is exposed A cross-sectional image obtaining step of irradiating an electron beam to the cross-section to obtain an image of a region of a predetermined size including the specific observation object; and a stereo image generating step, repeating the process multiple times in a predetermined direction at predetermined intervals. The cross-section processing step and the cross-sectional image obtaining step construct a three-dimensional stereoscopic image including the specific observation object based on the obtained plurality of cross-sectional images.

In the cross-section observation method of the present invention, a sample of an observation object is observed in advance using an optical microscope tube, and position coordinate information in the XYZ direction in which the specific observation object exists is obtained and stored. The position coordinates in the Z (depth) direction of the optical microscope tube are The focused stereo microscope is used as an optical microscope tube to obtain the observation while fixing the XY coordinate position and changing the focal position.

Based on the three-dimensional coordinate information of the specific observation object obtained in this way, the sample of the observation object is subjected to cross-section exposure processing by FIB. At this time, in a region where a specific observation object does not exist, processing is performed in a short time by increasing the processing interval by FIB, and a cross-sectional image is not particularly obtained. Then, after reaching a specific part including a specific observation object according to the position coordinate information, the sample is processed at a predetermined narrow interval to obtain a SEM cross-sectional image of a region including the specific observation object in the processed cross section.

Then, the processing position and SEM image of the FIB were saved using the group. After the acquisition of the image data of the specific portion including the specific observation object is completed, the acquisition of the cross-sectional image and the FIB processing at a narrow interval are completed, and the FIB processing is performed at a wide interval in a short time until it approaches the next specific portion. After the acquisition of the cross-sectional images of all the specific parts is completed, the processing is terminated. Alternatively, the processing interval is fixed so that a cross-sectional image is not acquired in a region without an object and a cross-sectional image is acquired in a region with an object. Thereby, desired information can be obtained efficiently.

As described above, according to the cross-section observation method of the present invention, the position of the coordinates where a specific observation object exists is grasped by using the optical observation of an optical microscope tube, so that the inclusion of the specific observation object can be performed quickly and efficiently. By observing a specific part of the image, it is easy to obtain a three-dimensional stereo image of a specific observation object.

In the present invention, the specific observation object is characterized in that There are various kinds of objects to be set, and the cross-section processing step is performed for each specific observation object.

In the present invention, a confocal stereo microscope is used as the optical microscope.

Further, in the present invention, in the cross-sectional image acquisition step, a cross-sectional composition image of the specific portion including the specific observation object is obtained by energy dispersive X-ray detection of the cross-section, and In the three-dimensional image generation step, a three-dimensional three-dimensional composition image including the specific observation object is constructed based on the obtained plurality of cross-sectional composition images.

A cross-section observation apparatus according to the present invention includes a sample stage on which a sample containing a specific observation object is placed, a focused ion beam lens barrel that irradiates the sample with a focused ion beam, and irradiates electrons of the sample with an electron beam. A beam tube; an optical microscope tube for optically observing the sample; a secondary electron detector for detecting secondary electrons generated from the sample or a reflection electron detector for detecting reflected electrons; and a control section, The optical microscope tube is used to specifically designate the existence position of the specific observation object in the sample to construct a three-dimensional stereoscopic image of a specific part including the specific observation object.

According to the cross-section observation apparatus of the present invention, the approximate position coordinates of a specific part including a specific observation object in a sample can be grasped in advance by an optical microscope tube. Therefore, it is possible to quickly process a sample using a focused ion beam lens tube. Close to the specific part, and use the focused ion beam tube for rough processing in areas other than the specific part. Parts are processed finely using a focused ion beam cylinder. Thereby, a high-resolution cross-sectional image including a specific portion of a specific observation object can be obtained quickly in a short time.

In addition, according to the cross-section observation device of the present invention, the electron beam is irradiated from the electron beam lens barrel to only a specific portion of the sample section formed by the focused ion beam lens barrel including a specific observation object to obtain a profile image. Compared with a conventional observation device that obtains a cross-sectional image over the entire area of the sample, the data capacity of the stored cross-sectional image can be significantly reduced, and a cross-section processing and observation device can be configured at low cost.

Furthermore, when obtaining a cross-sectional image of a specific part including a specific observation object by using an electron beam, the image can be imaged at a high resolution, and thus can be generated in comparison with a conventional observation device that obtains a cross-sectional image over the entire area of the sample. 3D stereo image with higher resolution.

In addition, the present invention is characterized by including an EDS detector that detects characteristic X-rays generated from the sample, and the control unit constructs a three-dimensional stereoscopic composition image of the specific portion.

According to the present invention, processing of a specific portion including a specific observation object can be performed with high accuracy in a short time, and thus a high-resolution three-dimensional stereoscopic image of the specific observation object can be easily and quickly generated.

10‧‧‧ Section processing observation device

11‧‧‧ Focused Ion Beam (FIB) Tube

12‧‧‧ Electron Beam (EB) Tube

13‧‧‧Optical microscope tube (optical microscope)

26‧‧‧Control Department

51‧‧‧EDS detector

FIG. 1 is a schematic configuration diagram showing a cross-section observation device according to a first embodiment.

FIG. 2 is a flowchart showing one embodiment of a method for observing a section in a stepwise manner.

FIG. 3 is a schematic diagram when a sample is observed with an optical microscope tube.

FIG. 4 is a schematic diagram showing a specific portion which is an acquisition region of an SEM image.

FIG. 5 is a flowchart showing a modification of the processing observation method.

FIG. 6 is a schematic configuration diagram showing a cross-section observation machine according to a second embodiment.

FIG. 7 is a schematic configuration diagram illustrating a cross-section observation apparatus according to a third embodiment.

FIG. 8 is a projection view according to a method for observing a cross-section according to a second embodiment.

FIG. 9 is a projection view according to a method for observing a cross-section according to a third embodiment.

FIG. 10 is a schematic configuration diagram showing a cross-section observation machine according to a fourth embodiment.

FIG. 11 is an explanatory diagram illustrating a cross-section processing observation method according to a fourth embodiment.

FIG. 12 is an explanatory diagram illustrating a cross-section observation method according to a fourth embodiment.

FIG. 13 is an explanatory diagram showing a cross-section observation method according to the fourth embodiment.

FIG. 14 is an explanatory diagram illustrating a cross-section observation method according to a fourth embodiment.

Hereinafter, a sectional processing observation method and a sectional processing observation apparatus according to the present invention will be described with reference to the drawings. In addition, each embodiment shown below will be specifically described in order to better understand the gist of the invention, and the invention is not limited thereto unless otherwise specified. In addition, in the drawings used in the following description, in order to easily understand the features of the present invention, the main part may be shown enlarged for the sake of convenience, and the dimensional ratios and the like of the constituent elements may not necessarily be the same as the actual ones.

(Section Processing Observation Device: First Embodiment)

FIG. 1 is a schematic configuration diagram showing a cross-section observation device according to a first embodiment.

The section processing observation device 10 according to the present embodiment includes at least a focused ion beam (FIB) lens barrel 11, an electron beam (EB) lens barrel 12, an optical microscope (OM) barrel 13, and a sample including a table (sample table) 15. Room 14. The focused ion beam barrel 11, the electron beam barrel 12, and the optical microscope barrel (optical microscope) 13 are respectively fixed in the sample chamber 14.

Irradiate the samples S that can be placed on the table 15 The focused ion beam (FIB) 21, the electron beam (EB) 22, and the visible light (VL) 23 are arranged in a manner of focusing the ion beam barrel 11, the electron beam barrel 12, and the optical microscope barrel 13.

When the focused ion beam 21 and the electron beam 22 which are irradiated from the focused ion beam barrel 11 and the electron beam 22 which are irradiated from the electron beam barrel 12 are respectively orthogonal on the sample S, the focused ion beam barrel 11 and the electron beam barrel 12 are arranged. In this case, the processed cross section can be irradiated with an electron beam vertically, and a high-resolution cross-sectional image can be obtained. Therefore, it is more preferable.

Here, as an example of the sample S, a biological sample embedded with a resin or the like can be mentioned. The observer observes, for example, cells (such as cells) included in such a biological sample as a specific observation object (attention part). In the case where the sample is a transparent biological sample, unlike ordinary materials such as metal, the inside of the biological sample can be observed through an optical microscope tube (optical microscope) 13. Therefore, the existence position of the attention area can be confirmed.

The optical microscope tube (optical microscope) 13 is arranged so that it can observe in the direction substantially the same as the irradiation direction of the electron beam 22. In addition, a part or all of the optical microscope tube 13 may be accommodated in the sample chamber 14, or may be arranged in another sample chamber arranged outside the sample chamber 14. In either case, it is preferable to arrange | position so that it can observe in the direction substantially the same as the irradiation direction of an electron beam.

As for the optical microscope tube (optical microscope) 13, for example, a confocal stereoscopic microscope including a laser light source in a light source is particularly preferably used. Confocal stereo display The micromirror can image a high resolution in the height (depth) direction (direction along the optical axis of the optical microscope) of the sample S. A confocal stereo microscope is mostly used to image a sample with minute unevenness on the surface. However, in this embodiment, in order to obtain the internal structure of the sample S, it is obtained in the depth direction. Use for high-resolution images.

For example, in a transparent sample S such as a biological sample, a laser is transmitted, and as long as a foreign material or tissue that does not transmit the laser exists in the sample S, they can be imaged. As is well known, a scanning mechanism that performs two-dimensional scanning on the sample S along the respective directions of the X-axis and the Y-axis uses laser scanning to form image information of the XY plane of the sample S, regarding the height (depth) of the sample. Information in the direction (Z axis) is obtained by taking in the Z position (the height information of the sample S) at the time of maximum brightness.

However, in the image obtained by the optical microscope tube (optical microscope) 13, the structure behind the specific observation object to be imaged cannot be known because the specific observation object is opaque. In this way, only the shape of the uppermost surface of the laser reflection can be known, but the in-plane position information (XY coordinates) and depth position information (Z coordinates) of the specific observation object can be obtained. To establish a target of where a specific observation object exists in the sample S.

On the other hand, in the case of observation using the focused ion beam 21 or the electron beam 22, even when there is transparency in the sample S, only the morphological information of the outermost surface of the sample S is obtained. therefore, Even if it is known in advance that there is a specific observation object inside the sample S, its existence position (coordinates) cannot be made obvious. In addition, the contrast between the optical microscope image and the SEM image may make it difficult to grasp the attention portion in the SEM image.

Therefore, by optical microscope observation using the optical microscope tube (optical microscope) 13, it is possible to obtain the coordinates of a specific region, that is, a small area in the sample S including the specific observation object before the cutting operation (section processing step) of the sample S. Then, the cutting operation is performed based on the coordinates of a specific portion of the specific observation object (section processing step). However, in order to make the acquisition area of the SEM image using the electron beam 21 with respect to the exposed section reliable, as long as Based on the form of the feature identified by the optical microscope tube (optical microscope) 13 and the electron beam 21, the position (coordinates) of a specific observation object can be specified based on the relative positional relationship using the reference point as a reference point.

The stage 15 is controlled by the stage control unit 19 and can mount the sample S, and moves and tilts in each of the XYZ directions, thereby adjusting the sample S in an arbitrary direction.

The section processing observation apparatus 10 further includes a focused ion beam (FIB) control unit 16, an electron beam (EB) control unit 17, and an optical microscope (OM) control unit 18. The focused ion beam control unit 16 controls the focused ion beam lens barrel 11 so that the focused ion beam 21 is irradiated at an arbitrary timing. The electron beam control unit 17 controls the electron beam lens barrel 12 so that the electron beam 22 is irradiated at an arbitrary timing.

The optical microscope control unit 18 feeds the optical microscope tube 13 The control is performed to move the position of the optical focus, and an observation image of the sample S is acquired and stored with each movement. The focal position is repeatedly fine-moved and stopped along one optical axis of the optical microscope tube 13 in a direction gradually approaching or distant from the optical microscope tube 13, and an image of the sample S is acquired at the time of the stop. Alternatively, the optical microscope image may be obtained by fixing the focal position of the optical microscope tube 13 and finely moving the table 15 in the vertical direction by the table control unit 19.

The cross-section observation device 10 further includes a secondary electron detector 20. The secondary electron detector 20 irradiates the sample S with a focused ion beam 21 or an electron beam 22 to detect the secondary electrons generated from the sample S.

In addition, a configuration in which a reflection electron detector (not shown) is provided instead of the secondary electron detector 20 or a configuration in which a reflection electron detector (not shown) is provided in addition to the secondary electron detector 20 is also preferable. The reflected electron detector detects the reflected electrons of the electron beam after being reflected by the sample S. A cross-sectional image of the sample S can be obtained using such reflected electrons.

The cross-section observation device 10 includes an image forming section 24 that forms an observation image of a section of the sample S, and a display section 25 that displays the observation image. The image forming unit 24 forms an SEM image based on a signal scanned by the electron beam 22 and a signal of the secondary electrons detected by the secondary electron detector 20. The display section 25 displays an SEM image obtained by the image forming section 24. The display unit 25 may be configured by, for example, a display device.

The cross-section observation device 10 further includes a control unit 26 and an input unit 27. The operator inputs various control conditions of the section processing observation device 10 via the input unit 27. The input unit 27 sends the inputted information to the control unit 26 send. The control unit 26 outputs control signals to the focused ion beam control unit 16, the electron beam control unit 17, the optical microscope control unit 18, the table control unit 19, the image forming unit 24, and the like, and controls the overall operation of the section processing observation device 10.

(Section Processing Observation Device: Second Embodiment)

In the first embodiment described above, a configuration in which part or all of the optical microscope tube (optical microscope) 13 is located in the sample chamber 14 has been described. However, the optical microscope tube (optical microscope) 13 is provided outside the sample chamber 14. also may.

FIG. 6 is a schematic configuration diagram illustrating a cross-section observation apparatus according to a second embodiment of the present invention. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted. In the section processing observation device 30, a second sample chamber 34 is formed outside the sample chamber 14, and an optical microscope tube (optical microscope) 33 is disposed in the second sample chamber 34.

The second sample chamber 34 in which a part or all of the optical microscope tube (optical microscope) 33 is provided has its inside vacuumed or atmospheric pressure. The inside of the sample chamber 14 to which the focused ion beam or electron beam is irradiated must be vacuum. However, the installation environment of the optical microscope tube (optical microscope) 33 is not obstructed even at atmospheric pressure. Therefore, the second sample chamber 34 is made to have an atmospheric pressure As a result, the volume of the sample chamber 14 that becomes a vacuum can be made small, and the efficiency of vacuum exhaust can be improved.

The sample S between the sample chamber 14 and the second sample chamber 34 The movement is performed by the sample holder 35 and the transfer rod 36 on which the sample S is placed. During the movement, after the transport rod 36 is fixed to the sample holder 35 and the sealed door (valve) 37 is opened, the sample holder 35 removed from the table 38 of the second sample chamber 34 is inserted into the sample chamber by the transport rod 36. In 14, the sample holder 35 is fixed on a table 15 in the sample chamber 14.

The stage 15 of the sample chamber 14 and the stage 38 of the second sample chamber 34 including the optical microscope tube (optical microscope) 33 are controlled by the stage control units 39a and 39b, respectively. The coordinate information at the stages 15 and 38 is stored in the control unit 26, and the stage 15 of the sample chamber 14 can be linked based on the coordinate information obtained at the stage 38 of the second sample chamber 34. Note that in FIG. 6, the description of the focused ion beam control unit, the electron beam control unit, and the like is omitted, but the configuration is the same as that of FIG. 1.

(Section Processing Observation Device: Third Embodiment)

Although the configuration in which the optical microscope tube (optical microscope) 13 is disposed in the second sample chamber 34 provided outside the sample chamber 14 has been described in the second embodiment described above, the optical microscope tube (the optical microscope tube) may not be provided. Optical microscope) 13 sample chamber.

FIG. 7 is a schematic configuration diagram showing a cross-section observation apparatus according to a third embodiment of the present invention. It should be noted that the same components as those in the second embodiment are denoted by the same reference numerals, and redundant descriptions are omitted. In the cross-section observation device 40, an optical microscope tube (optical microscope) 43 is independently arranged outside the sample chamber 14. In addition, a part of the common control section 46 is provided so that even in the focused ion beam control section or the electron beam control section (Refer to FIG. 1) The coordinates of a specific observation object (attention part) in the sample S obtained by the optical microscope tube (optical microscope) 43 are also read. By providing an optical microscope tube (optical microscope) 43 independently of the outside of the sample chamber 14, for example, the degree of freedom of the installation surface of the equipment, such as setting each one in another chamber to perform work, is increased.

(Section Processing Observation Device: Fourth Embodiment)

FIG. 10 is a schematic configuration diagram showing a sectional processing observation apparatus according to a fourth embodiment of the present invention. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted. The section processing observation device 50 includes an EDS detector 51 that detects X-rays generated from the sample S when the sample S is irradiated with an electron beam (EB), and an EDS control unit 52 that controls the EDS detector 51. The X-rays generated from the sample S include characteristic X-rays that are unique to each substance constituting the sample S, and the substances (compositions) constituting the sample S can be specifically specified using such characteristic X-rays.

The image forming unit 24 forms a composition image of a specific cross section of the sample S based on the scanning signal of the electron beam 22 and the characteristic X-ray signal detected by the EDS detector 51. The control unit 26 constructs a three-dimensional stereoscopic composition image based on the plurality of composition images. In addition, the composition image (EDS image) refers to the substance of the sample S at each electron beam irradiation point according to the detected characteristic X-ray energy, and the distribution of the substance in the irradiation region of the electron beam 22 is specified. Like.

By using the cross-section observation device of the fourth embodiment 50, so that a three-dimensional composition map of a specific part in the sample S can be constructed. A method of constructing a three-dimensional composition map using the section processing observation device 50 of the fourth embodiment will be described in a fourth embodiment of a section processing observation method described later.

The section processing observation device 50 of the fourth embodiment also includes the EDS detector 51 and the optical microscope tube 13 or the secondary electron detector 20, but the optical microscope tube 13 or the secondary electron detector can be omitted. 20.

(Section processing observation method: first embodiment)

Next, a cross-section observation method according to a first embodiment of the present invention using the above-mentioned cross-section observation device will be described with reference to FIGS. 1 and 2.

FIG. 2 is a flowchart showing one embodiment of a method for observing a section processing stepwise.

First, the target sample S is observed through an optical microscope tube (optical microscope) 13 to obtain position (XYZ coordinate) information of a specific observation object (attention part) contained in the sample S (position information acquisition step S10). The sample S is, for example, a biological sample. The sample S, which is an object, is fixed by embedding with resin or the like in advance, and is subjected to processing such as drying and dehydration. Regarding such a biological sample preparation process such as an embedding operation or a dehydration operation, a known technique may be used.

When the SEM observation is performed on the sample S subjected to such a treatment, an image of the surface of the sample S can be obtained, but a sample cannot be obtained. Image of the interior of product S. However, when observation is performed with an optical microscope tube (optical microscope) 13, light is transmitted in a transparent sample S such as a living organism, and a specific observation object such as a foreign object or a tissue that does not transmit light in the sample S (attention point) ), Can be visualized due to the difference in contrast.

FIG. 3A is an optical microscope image (schematic diagram) when the sample S is observed through the optical microscope tube 13. In order to project a view of an image observed by changing the focal position from the surface of the sample S to a predetermined depth, specific observation objects (attention portions) C1 and C2 appearing in the field of view are displayed on one screen. Let the XY coordinates of the optical microscope image be the coordinate system described in the lower left of FIG. 3A. The approximate center coordinates of the specific observation object C1 are (X1, Y1), and the approximate center coordinates of the specific observation object C2 are (X2, Y2). .

FIG. 3 (B) is an optical microscope image (schematic diagram) showing the depth direction with respect to the same field of view of the same sample S as FIG. 3 (A). Using the depth direction of the sample as the Z coordinate, it is shown from the surface Z0 of the sample S to the observation bottom surface Zn. The focus of the optical microscope tube 13 is adjusted in order from the surface toward the inside of the sample S (depth direction Z), and the optical microscope image at each focus position is stored in the control unit 26 together with the Z coordinate at this time.

Then, acquisition of an optical microscope image (planar image) using the optical microscope tube 13 is repeated from the surface of the sample S to a predetermined observation bottom surface Zn. By synthesizing (image processing) a plurality of optical microscope images (planar images) obtained in this way, the three The dimensional image can grasp the existence position (coordinate) of the specific observation object (attention part) C1, C2 in the depth direction Z in the sample S. In this way, the optical microscope tube (optical microscope) 13 is used to observe the sample S while fixing the XY coordinates and changing the optical focus position, thereby making it possible to approximate the three-dimensional coordinates in the sample S of the specific observation object (attention part). Become obvious.

Next, based on the XY coordinate information of the specific observation object (attention part) obtained by the optical microscope tube (optical microscope) 13, the focused ion beam 21 is irradiated from the focused ion beam lens barrel 11 to perform a cross-section forming process of the target sample S. (Section processing step S11).

FIG. 4 (A) is a schematic view showing the specific observation object C1 and the specific observation object C2 shown in FIG. 3 (A) as specific regions (image acquisition regions) that are acquisition regions of the SEM image. In the case of FIG. 4 (A), the image acquisition area (specific portion) of the specific observation object C1 is centered on (X1, Y1), which is the approximate center coordinate of the specific observation object C1. The length from the outermost end portion of the rectangular area is a rectangular area with one side ΔX1 and ΔY1. Similarly, the image acquisition area of the specific observation object C2 uses the coordinates (X2, Y2) as the center, and the length after adding a predetermined distance from the outermost end of the specific observation object is one side △ X2, △ A rectangular area of Y2.

The predetermined length refers to a margin area when three-dimensionally displaying an area including a specific observation object. When the margin area is excessively large, the three-dimensional image of the specific observation object becomes small. When there is too much margin, There is a case where it is difficult to observe the display direction of the cross section. Therefore, the operator only needs to appropriately determine the margin area in accordance with the observation method of the specific observation object. For example, it is only necessary to set the image acquisition range by about 10% of the length of each of the XY directions of the projection view of the specific observation object.

FIG. 4 (B) is a projection view of the depth direction Z of the sample S, and based on this image, a processing area where the cross section of the sample S is exposed by the focused ion beam 21 at a narrow interval is determined. Here, in FIG. 4 (B), the appearance position (the upper part of the specific observation object) of the specific observation object C1 in the observation field of view is set to Z11, and the specific observation object C1 disappears from the observation field of view. (The lower part of the specific observation object) is set to Z12. Similarly, the appearance position of the specific observation object C2 is Z21, and the disappearance position of the specific observation object C2 is Z22.

The range in which the sample S is thinned by the focused ion beam 21 at close intervals is determined, for example, as a length obtained by adding a predetermined length to the appearance coordinates and disappearance positions of a specific observation object. The predetermined length refers to a margin area when three-dimensional display is performed on a portion including a specific observation object. For the Z direction, for example, 10% of the length in the Z direction (Z12-Z11) of the specific observation object C1 is used as the margin area. From the Z coordinate Z1A where the margin area is added to the upper part of the Z coordinate Z11 to the Z coordinate Z1B where the margin area is added to the lower part of the Z coordinate Z12 as the processing area. Similarly for the specific observation object C2, the Z-coordinates Z2A to Z2B are used as the cross-section processing range for processing the sample S at a close interval using the focused ion beam 21.

The processing interval of the sample S using the focused ion beam 21 is as narrow as possible, and the resolution in the Z direction of a three-dimensional image constructed by a specific observation object is higher. On the contrary, when the specific observation object is extremely long in the Z direction, the number of acquired SEM images increases, and the accumulated image data increases. Therefore, it is preferable that the size of a specific observation object is grasped in advance by observation using an optical microscope tube (optical microscope) 13 and the capacity of the accumulated image data and the three-dimensional image of the specific observation object to be constructed are discussed in advance. After the resolution is determined, the processing interval using the focused ion beam 21 is determined.

It is only necessary to perform the cross-section processing using the focused ion beam 21 within a short period of time between Z0 to Z1A, Z1B to Z2A, and Z2B to Zn in such a Z-coordinate outside the processing range using a narrow interval. In addition, in this area, it is known that a specific observation object does not exist, and therefore, it is not necessary to intentionally acquire an SEM image. As a result, it is possible to reduce the time required for the cross-section processing of the sample S and reduce the storage capacity of the SEM image. Alternatively, if the section processing is performed at a fixed interval, image acquisition is performed when a specific observation object exists, and image acquisition is performed when the object does not exist, thereby shortening and storing time. Reduced capacity.

Next, an SEM image of a specific portion including a specific observation object in the cross section of the processed sample S is acquired and stored with the cross section position information (cross section image acquisition step S12). Based on the coordinates of the existence position of the specific observation object obtained by observation with the optical microscope tube (optical microscope) 13, a position including the specific observation object is obtained. The target small area is the SEM image of a specific part. Then, the processing position using the focused ion beam 21 and the SEM image, and the XY coordinates in the cross section (for example, the coordinates of the center of the SEM image) are stored in a group. For example, when a plurality of specific observation objects exist on one cross section, an SEM image of a specific portion including each specific observation object is obtained.

Next, it is determined whether the image acquisition of the specific observation object is completed (S13). A determination is made as to whether the processing using the focused ion beam 21 has reached a predetermined Z coordinate (for example, Z1B) at which processing is completed. After it is determined that the predetermined arrival position has been reached, the acquisition of the image data of the specific portion including the specific observation object is completed.

Then, the image acquisition and the processing using the focused ion beam 21 using a narrow interval are finished, and the cross-section processing using the focused ion beam 21 is performed at a wide interval until it approaches the area where the next specific observation object exists. In addition, if there is no next specific observation object, processing is terminated.

In this way, the existence position (coordinates) of a specific observation object in the sample can be grasped in advance by observation using an optical microscope tube (optical microscope) 13, and therefore, it can be performed quickly with a wide processing width until the specific observation is included. Processing of specific parts of objects. In addition, since image acquisition is not performed in a portion where a specific observation object does not exist, the observation time can be minimized and the storage area of the image can be made small. In addition, it is possible to obtain the information of the profile in more detail. In addition, the presence or absence of image acquisition can be set even if the processing width is fixed. Therefore, the time and storage area can be made small.

Next, a three-dimensional image of a specific observation object is constructed using the sectional position information and image data (stereoscopic image generation step S14). Here, for example, a computer (control unit 26) is used to generate (construct) a three-dimensional stereoscopic image of a specific observation object based on a plurality of cross-sectional images of a specific portion of the specific observation object and an image processing program.

Regarding the three-dimensional stereoscopic image of the specific observation object obtained in the stereo image generation step S14, the specific observation object can be freely observed from an arbitrary viewpoint, and an arbitrary cross-sectional image can also be reproduced. For example, the internal structure of a cell is observed.

As a modification of the above-mentioned cross-section observation method, as shown in the flowchart of FIG. 5, after the acquisition of the SEM image of the specific observation object is completed, a presence of a specific observation object that should be constructed by a three-dimensional stereo image is also provided. The determination step (S15) is also preferable.

In the embodiment described above, the case where there are two specific observation objects (attention parts) has been described. As a result of the optical microscope observation, it is determined that the specific observation object is only C1, and the processing is completed at the time point when the cross-section processing using the focused ion beam 21 reaches the Z coordinate Z1B. However, when there are a plurality of specific observation objects as shown in FIG. 3 and FIG. 4, at the time point when the processing of the narrow interval is completed by the cross-sectional processing of the focused ion beam 21 according to the flowchart shown in FIG. 5 (arrival Time point of the Z coordinate Z1B), and then the presence or absence of another specific observation object is determined (S15). Then, when another specific observation object exists, the cross-section processing step S11 and the cross-sectional image acquisition step S12 are repeatedly performed. In addition, there are no other specific observation objects In the case of an object, a three-dimensional stereoscopic image is generated in a stereoscopic image generation step S14 of a specific observation object.

(Section processing observation method: second embodiment)

In the first embodiment described above, as the simplest example in which there are a plurality of specific observation objects (attention portions), an example in which there is a distance away from each other or only one specific observation object appears in a cross section has been described. However, the present invention It is not limited to this.

This embodiment is a case where a plurality of specific observation objects (attention parts) coexist in the same XY plane (same Z coordinate), and the present invention can also be applied to the observation of such samples.

FIG. 8 is a projection view (schematic view) of a cross section (Z viewpoint) and an XZ plane (Y viewpoint) of an XY plane, which is prepared from image information obtained by observing a sample to be an object using an optical microscope in advance. Note that in FIG. 8, the same reference numerals as those in FIG. 2 have the same configuration, and redundant descriptions are omitted.

In this embodiment, the specific observation objects C3 and C4 coexist in the same Z coordinate, and a single specific observation object is smaller than the other. When the processing section reaches the Z coordinate Z31, the specific observation object C3 appears on the section. At this time, similarly to the method described above, a SEM image of a specific observation area, which is a predetermined observation area for a specific observation object C3, is started, and a cross-section processing using the focused ion beam 21 is started at a predetermined timing and interval.

Processing and image acquisition of the specific observation object C3 In the middle of the process, when the processing section reaches the Z coordinate Z41, another specific observation object C4 appears. The specific observation object C4 is previously known as an object that is long in the Z direction by observation with an optical microscope in advance. In the example shown in FIG. 8, in the Z coordinate Z41 to the Z coordinate Z32, the specific observation object C3 and the specific observation object C4 are exposed on the same cross section.

About the cross-section processing interval using the focused ion beam 21 between the Z coordinate Z41 to the Z coordinate Z32, the cross-section processing using the focused ion beam 21 was performed at an interval corresponding to the specific observation object C3, but the specific observation object C3 disappeared. The subsequent Z coordinate Z32 will continue to process at the same machining interval until the Z coordinate Z42. This is because when the processing interval of the same specific observation object is changed in the middle, a visual dissonance occurs in the three-dimensional stereoscopic image finally constructed. In addition, even when the three-dimensional stereoscopic images of the specific observation object C3 and the specific observation object C4 are compared, the Z direction can be compared with the same resolution by using the same processing interval.

In this manner, by storing the images of the specific observation object C3 and the specific observation object C4 and information on the processing interval, a three-dimensional stereoscopic image of the specific observation object C3 and the specific observation object C4 can be constructed based on the information.

(Section processing observation method: third embodiment)

In the first embodiment described above, the example in which the specific observation object (attention portion) exists along one curve has been described. However, the present invention can be applied even when the specific observation object is branched into a plurality. use. In addition, it can be applied even when a plurality of specific observation objects are integrated.

FIG. 9 is a projection view (schematic view) of a cross section of the XY plane (viewpoint in the Z direction) and a view of the XZ plane (viewpoint in the Y direction) obtained by observing a sample to be an object using an optical microscope in advance. Note that in FIG. 9, the same reference numerals as those in FIG. 2 have the same configuration, and redundant descriptions are omitted.

The specific observation object C5 has a shape such as a Y-shaped branch in the middle, and the thickness of each branch portion is not fixed. However, it is grasped in advance by observation with an optical microscope. Here, as shown in FIG. 9, the branch portions are respectively C5a, C5b, and C5c.

First, starting from the surface of the sample S (Z coordinate Z0), a cross-section is created using the focused ion beam 21, and at the Z coordinate Z5a1, a branch C5a of a specific observation object C5 appears. Processing and observation are continued using the predetermined processing interval of the focused ion beam 21 and the SEM observation area. When the processed section of the sample S reaches the Z coordinate Z5b1, the branch portion C5b of the specific observation object C5 appears.

At this time, the branch portion C5a and the branch portion C5b coexist in the processed cross section. In the case where the branch C5a and the branch C5b are integrated into the Z coordinate Z5c1 before the branch C5a and the branch C5b coexist on the same cross section, the size of each specific observation object is obtained according to a predetermined observation area (specific location). SEM image. It is preferable that the processing interval of the focused ion beam 21 be maintained in accordance with the size of the specific observation object that initially appears until the specific observation object disappears.

The observation area of the SEM may be appropriately changed according to the cross-sectional area of a specific observation object. In the case of FIG. 9, the cross-sectional area of the branch C5c gradually decreases between the Z coordinate Z5C1 to the Z coordinate Z52. However, the observation area may be changed each time according to the cross-sectional area of the branch C5c and a predetermined reference. . This makes it possible to reduce the amount of image data in a region where a specific observation object does not exist. In addition, according to the cross-section observation method of the present embodiment, even if the shape of the specific observation object is irregular, the specific observation object in the sample can be three-dimensionally and stereoscopically displayed at a high resolution, and the recorded image can be reduced. Data capacity. In addition, when a plurality of specific observation objects having different processing conditions and observation conditions are integrated into one body, the one with a close processing interval and the one with a high resolution may be matched. Accordingly, even when a plurality of objects are integrated into one body, observation information of a desired condition can be obtained automatically.

(Section processing observation method: fourth embodiment)

A fourth embodiment of the sectional processing observation method of the present invention using the sectional processing observation apparatus shown in FIG. 10 will be described with reference to FIGS. 10 to 14.

FIG. 11, FIG. 12, FIG. 13, and FIG. 14 are explanatory diagrams showing the observation order in the fourth embodiment of the sectional processing observation method of the present invention in steps.

First, in an X-ray CT apparatus, an X-ray CT image of the sample S is obtained.

Then, as shown in FIG. 11, X-rays of the sample S Observe the line CT image, determine the specific area (region of interest) Q in the small area of the sample S containing the specific observation object (attention part) C11, and obtain its three-dimensional position coordinate (XYZ coordinate) information (position information acquisition process) The specific observation object is contained in the sample S.

Next, based on the three-dimensional position coordinate information of the specific part Q, the focused ion beam 21 is irradiated from the focused ion beam lens barrel 11 toward the specific part Q in which the specific observation object C11 exists, and a section forming process of the specific part Q of the sample S is performed. Processing steps). The details of the cross-section forming process of the sample S using the focused ion beam 21 are the same as those of the first embodiment.

Then, the electron beam (EB) 22 is irradiated to the specific portion Q including the specific observation object C11 in the cross section of the sample S processed from the electron beam (EB) barrel 12 toward each of the predetermined intervals, and passes through the EDS detector. 51 detects a characteristic X-ray generated from a specific portion Q of the sample S. Then, as shown in FIG. 12, a cross-sectional composition image is constructed for each of the cross sections of the sample S. In this case, a composition image of the entire cross section in which the specific portion Q exists and a high-resolution composition image of a small region including the specific observation object C11 can be obtained.

For example, in the example shown in FIG. 12, three sections F1, F2, and F3 are set in advance at a specific portion Q, and each section is processed by focusing the ion beam 21. Then, for each of the sections F1, F2, and F3, the composition images K1a, K2a, and K3a of the entire section and the high-resolution section composition images K1b, K2b, and K3b of a small region including the specific observation object C11 are obtained. In the example of FIG. 12, in a specific part set as a rectangle In the sections F1, F2, and F3 of Q, with respect to the composition images K1a, K2a, and K3a of the entire section, there are specific observation objects (attention portions) C11 among the components G1, G2, and G3. Then, the specific observation object C11 is composed of the components G4, G5, and G6 based on the high-resolution cross-section composition images K1b, K2b, and K3b.

In addition, in each of the processed sections of the specific portion Q, only the cross-sectional composition image of the entire section may be acquired. In addition, when there are two or more specific observation objects, it is possible to obtain two or more heights. Resolution profile composition image. In addition, a cross-sectional composition image may be acquired from all the processed cross sections of the specific portion Q, or a cross-sectional composition image may be selectively acquired only with a specific cross-section.

Through the above steps, for example, as shown in FIG. 13, in the three sections F1, F2, and F3 of the specific portion Q, the composition image K1a, K2a, and K3a of the entire section and the small section including the specific observation object C11 are obtained The high-resolution cross-section composition images of the area are K1b, K2b, and K3b.

Next, using the section position information of the sample S, the composition images K1a, K2a, and K3a in each of the sections F1, F2, and F3, and the high-resolution section composition images K1b, K2b, and K3b, a specific observation including that shown in FIG. 14 was constructed. The three-dimensional three-dimensional composition image R of the specific part Q of the object (stereoscopic image generation step). Here, for example, a computer (control unit 26) is used to generate (construct) a three-dimensional stereoscopic composition image including a specific portion Q of a specific observation object by an image processing program.

The three-dimensional three-dimensional composition image R obtained through the three-dimensional image generation process is a three-dimensional composition image showing the components of the specific part Q as a whole, and The image composition of a high-resolution stereoscopic composition image after analyzing a specific observation object at a high resolution.

As described above, by detecting specific X-rays using the EDS detector 51 in each processing section, a cross-sectional composition image is obtained, and thereby a three-dimensional stereoscopic composition image R including a specific portion Q of a specific observation object can be obtained.

Several embodiments of the present invention have been described, but these embodiments are shown as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope of the invention or the scope of the invention, and the scope of the invention is included in the scope of the invention.

10‧‧‧ Section processing observation device

11‧‧‧ Focused Ion Beam (FIB) Tube

12‧‧‧ Electron Beam (EB) Tube

13‧‧‧Optical microscope tube (optical microscope) 13

26‧‧‧Control Department

14‧‧‧Sample Room

15‧‧‧Workbench (sample stage)

S‧‧‧sample

21‧‧‧Focused Ion Beam (FIB)

22‧‧‧ Electron Beam (EB)

19‧‧‧Workbench control department

16‧‧‧Focused ion beam (FIB) control unit

17‧‧‧ Electron Beam (EB) Control Department

18‧‧‧ Light microscope (OM) control unit

20‧‧‧ secondary electronic detector

24‧‧‧Image Formation Department

25‧‧‧Display

27‧‧‧Input Department

Claims (6)

A method for observing a cross-section processing, comprising: a position information acquisition step, observing an entire sample of an observation object using an optical microscope or an electron microscope, and obtaining an approximate of a specific observation object included in the sample in the sample; The three-dimensional position coordinate information of the cross-section processing step, based on the three-dimensional position coordinate information, irradiating a focused ion beam toward a specific part where the specific observation object exists in the sample, and exposing the cross-section of the specific part; An obtaining step of irradiating the cross section with an electron beam to obtain an image of a region of a predetermined size including the specific observation object; and a stereo image generating step of repeating the section processing a plurality of times in a predetermined direction at predetermined intervals. The step and the cross-sectional image obtaining step construct a three-dimensional stereoscopic image including the specific observation object based on the obtained plurality of cross-sectional images. The section processing observation method according to item 1 of the scope of patent application, wherein a plurality of types of the specific observation object are set, and the section processing step is performed for each of the specific observation objects. The method for observing a cross-section according to claim 1 or claim 2, wherein a confocal stereo microscope is used as the optical microscope. The section processing observation method according to item 1 or 2 of the patent application scope, wherein in the section image obtaining step, the characteristic including the specific observation object is obtained by energy dispersive X-ray detection of the section. A cross-sectional composition image at a fixed location, and in the stereo image generation step, a three-dimensional stereo composition image including the specific observation object is constructed based on the obtained plurality of cross-sectional composition images. A section processing observation device, comprising: a sample stage on which a sample containing a specific observation object is placed; a focused ion beam lens barrel which irradiates a focused ion beam to the sample; and an electron beam which irradiates an electron beam to the sample A lens barrel; an optical microscope tube for optically observing the sample; a secondary electron detector that detects secondary electrons generated from the sample or a reflective electron detector that detects reflected electrons; and a control section, which uses The optical microscope tube specifically designates the existence position of the specific observation object in the sample to construct a three-dimensional stereoscopic image including a specific part of the specific observation object. The sectional processing observation device according to claim 5 includes an EDS detector that detects a characteristic X-ray generated from the sample, and the control unit constructs a three-dimensional solid of the specific portion. Group imaging.