JP2002343294A - Complex electron microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a complex electron capable of obtaining accurate correspon dence between the SEM/STEM image and TEM image. SOLUTION: This complex electron microscope, capable of observing the SEM/STEM image and the TEM image, is provided with a first storage means 44 for storing SEM/STEM image rotation angle, magnification of the TEM image and the current value supplied to an imaging lens, in order to make the TEM image correspond to the SEM/STEM image rotation angle; a second storage means 45 for storing the magnification of the TEM image and the rotation angle, in order to make the SEM/STEM image correspond to the TEM image rotation angle; a computer 40 for correcting the magnification and the rotation angle according to the display mode, based on the data stored in the first and the second storage means; and a display means 35 for displaying the image corrected by the computer 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a SEM / STEM.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound electron microscope capable of displaying an image and a TEM image, and more particularly to an electron microscope capable of reducing a time required for searching for a visual field.

[0002]

2. Description of the Related Art Conventional TEM / STEM / SEM composite devices have been developed as TEM attachments.
In recent years, these devices have come to be used by adding an analysis function such as elemental analysis by X-ray spectroscopy or electron beam energy loss spectroscopy. In the analysis, information on local elements of the sample is obtained by a point, line, and plane scanning method, that is, a SEM / STEM mode.

FIG. 8 is a conceptual diagram showing the configuration in the SEM / STEM mode. The electron beam (electron beam) focused by the electron lens L <b> 1 is deflected and scanned by the deflector 8 and irradiated onto the sample 1. At this time, the secondary electrons generated from the surface of the sample 1 are detected by the detector 2. As the detector 2, for example, a detector is used in which a scintillator that emits light when an electron strikes it and a PMT (photomultiplier tube) that receives the light emitted by the scintillator, converts it again into electrons, and multiplies the electrons again. .

The secondary electron signal obtained by the detector 2 is amplified by the following amplifier 3 and then sent to the CRT 4 as a luminance signal, so that the screen of the CRT 4 shows the intensity of the secondary electron generated in the sample 1. The image (S
(EM image) is displayed (SEM mode or S
This will be referred to as an EM image display mode).

On the other hand, the electron beam (electron beam) transmitted through the sample 1 is focused by the electron lens L 2 and input to the detector 5. The detector 5 generates an electric signal corresponding to the input transmitted electron beam. Here, as the detector 5, for example, a detector in which the above-described scintillator and PMT are combined is used. The output of the detector 5 enters the following amplifier 6 and is amplified. The amplified transmitted electron signal changes the luminance on the CRT 7 in accordance with the intensity of the
Display an image (STEM image) on RT7 (STE above)
M mode or STEM image display mode). Here, the CRTs 4 and 7 may be shared.

Here, as the detectors 2 and 5 of the SEM system and the STEM system, detectors each combining a scintillator and a PMT are used, but secondary electrons are drawn into the detector 2 of the SEM system. Electrodes are provided, and + 10k
The difference from the detector 5 is that a voltage of about V is applied.

FIG. 9 is a conceptual diagram of the configuration in the TEM mode. The electron beam EB that has passed through the electron lens L3 is
Irradiated. At this time, the electron beam transmitted through the sample 1 is enlarged and projected on the fluorescent screen 10 by the electron lens L4. The operator can observe the image on the fluorescent screen.

Further, the transmitted image displayed on the fluorescent screen 10 is transmitted through an optical lens (or an optical fiber) 11.
An image is formed on the TV camera 12, photographed by the TV camera 12, and displayed on the CRT 13 (the above is referred to as a TEM mode or a TEM image display mode). Here, in the case of the SEM / STEM / TEM composite device, the CRT
13 may be shared with the CRT 4 or 7. SEM /
The difference between the STEM image and the TEM image is that, in the SEM / STEM mode, the sample is scanned with a narrowly focused electron beam, whereas in the TEM mode, the sample is irradiated with a parallel and thick beam.

Normally, a user searches for a characteristic visual field such as a crystal defect or a crystal interface using a TEM and analyzes the visual field. In addition, SEM / STEM
In some cases, a high-resolution image or an electron diffraction pattern at that location is obtained in a TEM mode.

When the above-described composite apparatus is used for such a purpose, the correspondence between the TEM image and the field of view of the SEM / STEM image is very important. You will be forced to look for In order to solve such a problem, a circuit for storing the current value of the electron beam deflector is provided in each of the TEM mode and the SEM / STEM mode so that the fields of view match in each mode.

[0011]

However, the SEM / S
The TEM image and the TEM image have different image properties (for example, the SEM image shines where particles are present, the STEM image, the TEM image
The image becomes dark where particles are present), and it is difficult to correspond to the visual field.

Further, in the conventional electron microscope, since the detection method is different in each mode, the image rotates in the TEM mode during image formation, so that it is difficult to confirm the visual field in each mode. Met. Further, in the conventional microscope, since the TEM image is displayed on the fluorescent screen in the image observation room and the SEM / STEM image is displayed on the CRT, it is difficult to compare the images between the two modes. .

The present invention has been made in view of such a problem, and an object of the present invention is to provide a compound electron microscope capable of accurately associating a SEM / STEM image with a TEM image.

[0014]

Means for Solving the Problems The first invention for solving the above-mentioned problems is a scanning electron microscope (SEM) mode / scanning transmission electron microscope (STEM) mode and a transmission electron microscope (TEM) mode. With SEM / STE
A compound electron microscope capable of observing an M image and a TEM image, comprising scanning means for a scanning electron microscope (SEM) mode / scanning transmission electron microscope (STEM) mode, a magnification of the TEM image, and a magnification thereof. And a scanning electron microscope (SEM) mode based on the data stored in the storage means.
SE in scanning transmission electron microscope (STEM) mode
The M / STEM image is characterized by comprising: a computer for performing a correction for adjusting the M / STEM image to the rotation angle of the TEM image; and a display unit for displaying an image corrected by the computer.

With such a configuration, the rotation angle (the direction of the image) of the SEM / STEM image can be adjusted with respect to the TEM image that rotates according to the magnification. As a result, the corresponding area between the SEM / STEM image and the TEM image is displayed on the same display means in a state where the correspondence between the magnification and the rotation angle is established, so that the correspondence between the SEM / STEM image and the TEM image is accurately obtained. Can be.

The second invention of the present invention relates to a scanning electron microscope (S
EM) mode / scanning transmission electron microscope (STEM) mode and transmission electron microscope (TEM) mode.
A composite electron microscope capable of observing an EM / STEM image and a TEM image, comprising a scanning means for a scanning electron microscope (SEM) mode / scanning transmission electron microscope (STEM) mode, and a transmission electron microscope ( A plurality of lenses of an imaging system for a (TEM) mode, and an SEM / S for adjusting the rotation angle of the TEM image to the rotation angle of the SEM / STEM image.
A first storage unit in which the magnification of the TEM image with respect to the rotation angle of the TEM image and a current value flowing through each lens of the TEM imaging system are stored, and the rotation angle of the SEM / STEM image is adjusted to the rotation angle of the TEM image. A second storage unit in which the rotation angle of the image with respect to the magnification of the TEM image is stored, and correcting the rotation angle in accordance with the display mode based on the data stored in the first or second storage unit. And a display means for displaying an image corrected by the computer.

According to this structure, the direction of the TEM image can be adjusted to the SEM / STEM image displayed by being arbitrarily rotated, and the SEM / STEM image is rotated with respect to the TEM image rotated according to the magnification. Can be adjusted to the rotation angle (the direction of the image). Thereby, SEM / STEM
Since the corresponding area between the image and the TEM image is displayed on the same display means in a state where the correspondence between the magnification and the rotation angle is established, the SEM / S
The correspondence between the TEM image and the TEM image can be accurately determined.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the present invention, not only the matching of the visual fields, but also the magnification and the rotation angle of the visual fields are made simultaneously or one of them is made to coincide with the other. In the present invention,
It is assumed that a TV device is provided so that a TEM image can be observed on a CRT.

In the figure, reference numeral 20 denotes an electron beam (electron beam)
, CL1 and CL2 are condenser lenses that focus the electron beam generated from the electron gun 20, and CM is a condenser mini-lens that also focuses the electron beam. C
LA1 and CLA2 are scanning / deflection coils (scan coils) for scanning / deflecting the electron beam in the X and Y directions, respectively. 21 is a sample irradiated with the electron beam, 22
S is for detecting secondary electrons generated from the surface of the sample 21.
EM signal detector. The SEM signal detector 22 is, for example, a detector that combines a scintillator that emits light when an electron hits it and a PMT (photomultiplier tube) that receives the light emitted by the scintillator, converts it again into electrons, and multiplies the electrons again. Is used.

The above-described electron gun 20, condenser lenses CL1, CL2, CM, scanning / deflection coil CLA1,
The CLA 2 and the SEM signal detector 22 constitute a detection system of a scanning electron microscope (SEM).

OL is an objective lens for expanding an electron beam transmitted through the sample 21, and OM is an objective mini lens for expanding an electron beam transmitted through the sample 21. OL is used when the magnification of the image is large, and OM is used when the magnification of the image is small. OL and OM are not used at the same time. ISC1 and ISC2 are image shift coils for aligning the lens axes of the imaging system, and are provided in the X and Y directions, respectively.

IL1, IL2, IL3 and PL are imaging lenses for imaging a transmitted electron beam. PL is called a projector lens and has a higher magnification than IL1, IL2, and IL3. Since a lens used in a TEM is generally of an electromagnetic type, an image is rotated according to the magnification of the lens. However, IL1, IL2, I
If a plurality of lenses such as L3 and PL are used to properly combine the magnifications of the lenses, the image is prevented from rotating while the total magnification obtained by combining the plurality of lenses is kept constant. Arbitrary rotation can be given. The PLA is a projected image shift coil for correcting that the center of enlargement of the image is shifted from the center position.

Reference numeral 23 denotes a first fluorescent screen for receiving transmitted electrons, and reference numeral 24 denotes a STEM signal detector for detecting an image formed on the fluorescent screen 23. As the first fluorescent screen 23, for example, a fluorescent substance that emits light by receiving transmitted electrons is used, and as the STEM signal detector 24,
For example, a PMT (photomultiplier tube) that converts an optical signal into an electric signal is used. Reference numeral 25 denotes a second fluorescent screen that receives transmitted electrons. The second fluorescent screen 25 has a fluorescent screen, and emits light by an incident electron beam. The first fluorescent screen 23 and the second fluorescent screen 25 are configured to be movable in the directions shown in the figure. For example, when obtaining a TEM image, the fluorescent screen 23 moves so that the electron beam is directly applied to the second fluorescent screen 25.

An optical fiber 26 optically guides the transmitted electron image converted into an optical image by the second fluorescent screen 25.
Reference numeral 7 denotes a TV camera that captures a transmitted electron image transmitted from the optical fiber 26. Although not shown, a third fluorescent screen that receives the transmitted electron image on the phosphor screen is provided, and the transmitted electron image can be observed with the naked eye. At this time, the first and second fluorescent screens 23, 2
Reference numeral 5 moves to the side so that the transmitted electron image is visualized on the third fluorescent screen.

The condenser lenses CL1, CL2, CM,
Scan / deflection coils CLA1, CLA2, objective lens OL
(Or mini lens OM), image shift coil ISC1, I
SC2, imaging lenses IL1, IL2, IL3, PL, projected image shift coil PLA, fluorescent screen 23, STE
The M signal detector 24 constitutes a STEM detection system. Further, condenser lenses CL1, CL2, CM, objective lens OL (or mini lens OM), image shift coils ISC1, ISC2, imaging lenses IL1, IL2, IL.
3, a PL, a projection image shift coil PLA, a fluorescent screen 25, an optical fiber 26, and a TV camera 27 represent a TEM detection system.

Reference numeral 28 denotes a scanning system control unit (scan control circuit) for controlling the scanning system, 29 denotes a deflection system control unit (deflector control circuit) for controlling the deflection system, and 30 denotes a lens system control unit for controlling the lens system. (Lens control c
ircuit). In the scanning system control unit 28,
By adjusting the components in the X and Y directions of the current supplied to the scanning / deflection coils CLA1 and CLA2, S
The EM / STEM image can be arbitrarily rotated. At this time, a certain scanning direction is defined as a rotation angle of 0 °. Similarly, the lens system controller 30 arbitrarily rotates the TEM image while keeping the magnification of the TEM image constant by changing the combination of currents supplied to the imaging lenses IL1, IL2, IL3, and PL. It can be made to be. Also in this case, the direction corresponding to the rotation angle of 0 ° of the SEM / STEM image is defined as T
The rotation angle of the EM image is set to 0 °.

Reference numeral 31 denotes an addition circuit which receives signals from the scanning system control unit 28 and the deflection system control unit 29, adds these signals, and supplies the signals to the scanning / deflection coils CLA1 and CLA2. The addition circuit 31 receives the scanning signal supplied from the scanning system control unit 28 and the optical axis adjustment signal supplied from the deflection system control unit 29, and adds the optical axis adjustment signal to the scanning signal to perform scanning / scanning. This is applied to the deflection coils CLA1 and CLA2.

The outputs of the deflection system controller 29 are output from the image shift coils ISC1, ISC2 and the projected image shift coil PSC.
It is also provided to the LA and controls the deflection of the electron beam. The lens system controller 30 includes condenser lenses CL1, C
Control signals are given to L2, CM, objective lens OL (or OM), and imaging lenses IL1, IL2, IL3, and PL.

Reference numeral 32 denotes the SEM signal detector 22 and the STE
An image signal amplifier (image signal amplifier) that receives and amplifies the output of the M signal detector 24. Reference numeral 40 denotes a computer for controlling the entire apparatus. An image signal interface (ITF) 33 is connected between the image signal amplifying unit 32 and the computer 40 and converts an output (analog signal) of the image signal amplifying unit 32 into a digital image signal. Connected to the TV
The capture card converts an output signal of the camera 27 into a digital image signal. A display unit 35 is connected to the computer 40 and displays image information in each mode (SEM / STEM mode, TEM mode). As the display unit 35, for example, a CRT is used. An operation unit 36 is used to specify a display image mode to the computer 40 and to input various commands.
As the operation unit 36, for example, a keyboard is used.

In the computer 40, 41 is a scan interface (ITF) connected between the scanning system control unit 28 and the computer 40, 42 is a deflection interface (ITF) connected between the deflection system control unit 29 and the computer 40, 43 Is a lens interface (ITF) connected between the lens system control unit 30 and the computer 40.

Reference numeral 44 denotes T as the rotation angle of the SEM / STEM image.
The magnification and rotation angle of the SEM / STEM image when aligning the EM images, and the TEM imaging system lenses (IL1, IL2, IL
3, PL), a memory (hereinafter abbreviated as memory 1) as first storage means for storing a current value flowing through
TEM when matching SEM / STEM image to image rotation angle
This is a memory (hereinafter abbreviated as memory 2) as second storage means for storing the magnification and rotation angle of the image and the current value flowing through the scanning / deflection coils (CLA1, CLA2) of the SEM / STEM. Reference numeral 46 denotes an image memory for storing image signals in each display mode (SEM / STEM mode, TEM mode). The operation of the device configured as described above will be described below.

(1) SEM / STEM image display mode When the SEM image / STEM image display mode is set from the operation unit 36, the computer 40 performs the SEM image / STEM image display operation. That is, secondary electrons generated by the electron beam irradiated on the sample 21 are detected by the SEM signal detector 22 and converted into electric signals. The output of the SEM signal detector 22 is amplified by the image signal amplifier 32. The image signal amplifier 32 converts the secondary electron signal into an image signal
3, the image signal interface 33 converts the secondary electron signal into a digital image signal. This digital image signal is temporarily stored in the image memory 46. The image signal stored in the image memory 46 is read out by the computer 40 and displayed on the display unit 35.

On the other hand, the electron beam transmitted through the sample 21 is focused by the objective lens OL (or OM) through the imaging lenses IL1, IL2, IL3 and PL, and then the fluorescent screen 2
3 is irradiated. The fluorescent screen 23 is made of a fluorescent substance, and emits light according to the intensity of the emitted electron beam. This light is converted into an electric signal by a STEM signal detector (PMT: photomultiplier tube) 24 and then amplified by an image signal amplifier 32. The output of the image signal amplifier 32 enters the image signal interface 33 and is converted into a digital image signal. This digital image signal is temporarily stored in the image memory 46. The image signal stored in the image memory 46 is read out by the computer 40 and displayed on the display unit 35.

As described above, the SEM is displayed on the display unit 35.
The image and the STEM image are displayed simultaneously or individually.

(2) TEM image display mode When the TEM image display mode is set from the operation unit 36,
The computer 40 performs a TEM image display operation. However, here, for the sake of explanation, it is assumed that the operation is performed by giving priority only to the magnification of the image and ignoring the rotation of the image. Therefore, when the magnification of the image is determined, each of the imaging lenses IL1 to IL3 and PL is controlled under conditions suitable for realizing the magnification, but the image is rotated accordingly. Therefore, the amount of rotation with respect to the magnification of the image is, for example, experimentally obtained in advance.

In the case of the TEM image display mode, the sample 21 is irradiated with a parallel and thick electron beam. In this case, no scanning signal is added to the scanning / deflection coils CLA1 and CLA2. The electron beam transmitted through the sample 21 is transmitted to each imaging lens IL1.
~ IL3 and PL are rotated each time they pass, and the imaging lens P
An image is projected on the fluorescent screen 25 through the L.
The image converted into the light is guided to a TV camera 27 by an optical fiber 26. The TV camera 27 captures a TEM image. The TEM image signal captured by the TV camera 27 is amplified by the image signal amplifying unit 32, converted into a digital image signal by the image signal interface 33, and stored in the image memory 46.

(3) Switching from SEM / STEM image display mode to TEM image display mode The SEM image / STE described in (1) is operated by the operation unit 36.
It is assumed that the mode is switched from the M image display mode to the TEM image display mode. When reading the switching instruction, the computer 40 reads the switching instruction at the same magnification and the same rotation angle as the SEM / STEM image.
The imaging lens (IL1, I
L2, IL3, and PL).

For this purpose, the computer 40
The data stored in the memory 1 is read. FIG. 2 is a diagram showing the contents of data stored in the memory 1.
In the figure, × 1000 indicates the magnification of the SEM / STEM image (actually, even if the magnification is changed in the SEM / STEM mode, the image does not rotate. Therefore, it should be correctly referred to as the magnification of the TEM image. Magnification and TE
Since it is assumed that the magnification of the M image is matched,
SEM / STEM image magnification), angle is SEM / S
The rotation angle of the TEM image, IL1, IL2, IL3, and PL indicate each lens of the imaging system. Then, a current value Kθi flowing through the lens of the imaging system necessary to obtain a TEM image having the same magnification and the same rotation angle as the SEM / TEM image displayed at the specified magnification and the specified rotation angle is stored. (Θ is the rotation angle, i is the number of each lens in the imaging system). Here, the angle is set at an interval of 1 ° from 0 ° to 359 °, but the angle is not limited to this. Such a table is provided for each magnification. The current value of this data table can be obtained in advance, for example, experimentally.

In the case of the TEM image display mode, the sample 21 is irradiated with a parallel and thick electron beam. In this case, no scanning signal is added to the scanning / deflection coils CLA1 and CLA2. The electron beam transmitted through the sample 21 is transmitted to each imaging lens IL1.
~ IL3 and PL are rotated each time they pass, and the imaging lens P
An image is projected on the fluorescent screen 25 through the L.
The image converted into the light is guided to a TV camera 27 by an optical fiber 26. The TV camera 27 captures a TEM image. The TEM image signal captured by the TV camera 27 is amplified by the image signal amplifying unit 32, converted into a digital image signal by the image signal interface 33, and stored in the image memory 46.

For example, when the rotation angle of the SEM / STEM image is 0
When scanning is performed in degrees, the SE displayed on the display unit 35 is displayed.
The M / STEM image is an image without rotation. Where TEM
If the current value of the imaging lens is set arbitrarily, the electron beam is rotated each time it passes through one imaging lens, so that the TEM image displayed on the display unit 35 is SEM / STE
The magnification and the rotation angle are different from those of the M image, making it difficult to perform contrast observation.

Therefore, the magnification of the SEM / STEM image is x1.
000, and the rotation angle is 0 °, the computer 40 reads the current values K01, K02, K03, and K04 to be passed through the respective imaging system lenses stored in the memory 1 and outputs the lens system via the lens interface 43. It operates so that the above-mentioned current value flows from the control unit 30 to the imaging lens. As a result, the TEM image displayed on the display unit 35 is displayed as an image having the same magnification and the same rotation angle (here, 0 °) as the SEM / STEM image, and enables observation in comparison with the SEM / STEM image.

Next, an adjustment method when rotating the SEM / STEM image will be described. FIG. 3A shows the sample when the rotation angle is 0 °. The horizontal axis is X and the vertical axis is Y. When such a sample is scanned at a rotation angle of 0 °, the SEM image displayed on the display unit 35 becomes an image as shown in FIG. Here, when the scanning direction of the sample is rotated by θ with respect to the X axis (horizontal direction) as shown in FIG.
The SEM image displayed on the display unit 35 is as shown in FIG.

Therefore, the SEM / STEM
When the switching from the image to the TEM image is instructed, the computer 40 sets the current value flowing through the imaging lens so that the displayed TEM image has the same magnification and the same angle as the display state (c) of the SEM / STEM image. To adjust. Referring to the table shown in FIG. 2, current values flowing through the imaging system lens when scanning while rotating by an angle θ are Kθ1, Kθ2,
Kθ3 and Kθ4. The computer 40 controls the lens system controller 30 so that this current value flows through the imaging lens.
Control.

As a result, the obtained TEM image is as shown in FIG. Here, the reason why the brightness of the pattern “H” is opposite to that in the case of FIG. 3C is that, in the case of a transmission image, the pattern portion does not allow an electron beam to pass.

(4) Switching from TEM image to SEM / STEM image First, the apparatus is set to the TEM mode in which the image rotation described in (2) TEM image display mode is ignored, and the TEM image is displayed on the display unit 35. It is assumed that Here, when an instruction to switch to the SEM / STEM image is issued from the operation unit 36, the computer 40 recognizes the switching instruction. Here, the computer 40 uses the SEM / STE from the TEM image.
When switching to the M image, the current value flowing through the scanning / deflection coils CLA1 and CLA2 is adjusted so that the magnification and the rotation angle are the same as those of the TEM image. For this purpose, reference is made to the memory 2.

FIG. 5 is a diagram showing the contents of the data stored in the memory 2. This table includes the magnification of the TEM image and the rotation angle at the magnification.

Now, for example, when the TEM image is obtained from the rotation angle θ (magnification ×
When 1000 is displayed at θ = θ1), the computer 40 refers to the table of the memory 2 and scans / deflects the coils required to display the SEM / STEM image at the same magnification and the same rotation angle. Current values Ix and Iy to be passed through CLA1 and CLA2 are calculated from Ixo, Iyo, and θ. Ixo and Iyo are current values of each coil when rotation correction is not performed, and are determined by the magnification of the SEM / STEM image.

Ix = Ixo · cos θ + Iyo · sin θ Iy = Iyo · cos θ−Ixo · sin θ Then, the scanning system control unit 28 is controlled via the scan interface 41, and the scanning / deflection coils CLA1 and CLA are controlled.
The current values Ix and Iy are respectively added to the values 2 and 2 to flow. As a result, the SEM / STEM image is displayed at the same magnification and the same rotation angle as the TEM image, and comparative observation can be easily performed. Note that the current values Ixo and Iyo and the rotation angle θ
The current values Ix and Iy of the calculation result of the above may be added to the memory 2 and stored in a table.

FIG. 6 is a diagram showing a display example of the display unit 35. A TEM image, a STEM image, and an SEM image are displayed. According to the present invention, since the SEM / STEM image signal and the TEM image signal can be stored in the image memory 46, the SEM / STEM image and the TEM image can be displayed on the display unit 35 simultaneously or individually. Can be. Here, the TEM image / STEM image and SEM
The image is inverted because the SEM image shows a secondary electron image generated from the surface of the sample, while the STE image shows
This is because the M / TEM image displays a transmission electron image of the sample.

FIG. 7 is an explanatory diagram of the positional relationship between the sample and the TEM image. 1 are denoted by the same reference numerals. In the figure, reference numeral 50 denotes a deflector for deflecting an electron beam in x and y directions in the SEM / STEM mode, 21 denotes a sample,
Reference numeral 51 denotes an electron lens that magnifies the electron beam transmitted through the sample 21 by m times, and 52 denotes a T image formed on a TV fluorescent screen.
It is an EM image. The deflector 50 is the deflection / scanning coil C of FIG.
The electron lens 51 corresponds to the imaging lenses IL1, IL2, IL3, and PL of FIG. 1 corresponding to LA1 and CLA2. The electron beam transmitted through the sample 21 is magnified m times by the electron lens 51, and is imaged on the fluorescent screen for TV to obtain a TEM image as shown in the figure. Here, the length of the sample 21 in the x direction is Lx, the length of the sample 21 in the y direction is Ly, and the image formed on the TV fluorescent screen by the electron lens 51 is Tx.
The rotation angle of the EM image from the sample 21 is θ, and the length in the x direction is L
Assuming that dx, the length in the y direction is Ldy, the magnification is m, the visual field deviation ddx in the x direction, and the visual field deviation ddy in the y direction, Lx,
Ly is represented by the following equations.

Lx = (Ldx · cos θ + Ldy · si
nθ + ddx) / m Ly = (Ldy · cos θ−Ldx · sin θ + dd
y) / m In the above embodiment, the SEM / STEM image and the TEM
Although the same image is displayed on the display unit 35 of the computer 40, the image may be displayed on a plurality of display units.
It may be displayed on a dedicated display section for the / STEM image or a display section dedicated to the TEM image. Further, the mode in which the magnification and the rotation angle are made to coincide with each other and the mode in which the magnification and the rotation angle are not made to coincide with each other in the conventional manner may be switched. The switching in this case can be performed from the operation unit 36 attached to the computer 40.

In the above description, the lens of the imaging system is I
L1, IL2, IL3, and PL were set in four stages.
With more than one step, the object of the present invention is achieved. Furthermore, the objective lens OL and the objective mini-lens OM also rotate the TEM image, but the above description without considering this also achieves the object of the present invention. In addition, in the above description, the SEM / S
Although it is assumed that the magnification of the TEM image and the magnification of the TEM image are the same, the magnification of the SEM / STEM image and the magnification of the TEM image are different, and only the rotation angle may be corrected. It is easily possible from the above description.

[0054]

The rotation angle (the direction of the image) of the SEM / STEM image can be adjusted with respect to the TEM image which rotates according to the magnification. SEM / ST displayed with any rotation
The direction of the TEM image can be matched to the EM image, and
SEM / STE for TEM image rotating according to magnification
The rotation angle (image direction) of the M image can be adjusted.

As described above in detail, according to the present invention, (1) the TEM image rotated according to the magnification
The rotation angle (the direction of the image) of the EM / STEM image can be adjusted, and (2) the SEM displayed by rotating it arbitrarily
The direction of the TEM image can be matched with the / STEM image. As described above, by displaying the image on the display unit with the magnification and the rotation angle of the SEM / STEM image and the TEM image matched, the correspondence of the visual field can be improved. Further, since the image information of each mode is stored, the user can compare and observe each image on the display unit. Also, since the magnification and the rotation angle match, the user can intuitively check the visual field without searching for the visual field.

[0056]

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing contents of data stored in a memory 1;

FIG. 3 is an explanatory diagram of a sample in a scanning direction.

FIG. 4 is a diagram showing a display example of a TEM image.

FIG. 5 is a diagram showing the contents of data stored in a memory 2;

FIG. 6 is a diagram illustrating a display example of a display unit.

FIG. 7 is an explanatory diagram of a positional relationship between a sample and a TEM image.

FIG. 8 is a conceptual diagram of a configuration in a SEM / STEM mode.

FIG. 9 is a conceptual diagram of a configuration in a TEM mode.

[Explanation of symbols]

20 electron gun, 21 sample, 22 SEM signal detector,
23 first fluorescent screen, 24 STEM signal detector, 25 second fluorescent screen, 26 optical fiber,
27 TV camera, 28 scanning system controller, 29 deflection system controller, 30 lens system controller, 31 addition circuit, 32
Image signal amplifier 33 Image signal interface (I
TF), 34 capture card, 35 display, 36
Operation unit, 40 computer, 41 scan interface, 42 deflection interface, 43 lens interface, 44 memory 1, 45 memory 2, 46
Image memory, CL1, CL2, CM condenser lens, CLA1, CLA2 scanning / deflection coil, OL objective lens, OM objective mini lens, ISC1, ISC2
Image shift coil, IL1, IL2, IL3, PL Imaging lens, PLA Projected image shift coil

Claims (6)

[Claims] 1. A composite having a scanning electron microscope (SEM) mode / scanning transmission electron microscope (STEM) mode and a transmission electron microscope (TEM) mode for observing a SEM / STEM image and a TEM image. An electron microscope, comprising: scanning means for a scanning electron microscope (SEM) mode / scanning transmission electron microscope (STEM) mode; and storage means for storing a TEM image magnification and an image rotation angle at the magnification. And SEM / STEM images in a scanning electron microscope (SEM) mode / scanning transmission electron microscope (STEM) mode based on the data stored in the storage means.
A compound electron microscope comprising: a computer for performing a correction for adjusting to a rotation angle of an M image; and display means for displaying an image corrected by the computer. 2. The method according to claim 1, wherein the correction is performed by the computer based on a rotation angle stored in the storage unit, and the scanning unit is controlled based on a result of the calculation. 2. The composite electron microscope according to 1. 3. The storage means stores in advance a result of calculating a value to be corrected for an SEM / STEM image based on a rotation angle of the TEM image, and controls the scanning means based on the result. 2. The compound electron microscope according to claim 1, wherein: 4. A composite having a scanning electron microscope (SEM) mode / scanning transmission electron microscope (STEM) mode and a transmission electron microscope (TEM) mode for observing a SEM / STEM image and a TEM image. An electron microscope, comprising: scanning means for a scanning electron microscope (SEM) mode / scanning transmission electron microscope (STEM) mode; and a plurality of imaging system lenses for a transmission electron microscope (TEM) mode. TE for the rotation angle of the SEM / STEM image to adjust the rotation angle of the TEM image to the rotation angle of the SEM / STEM image
First storage means for storing a magnification of the M image and a current value flowing through each lens of the TEM image forming system; and a magnification of the TEM image for adjusting the rotation angle of the SEM / STEM image to the rotation angle of the TEM image. A second storage unit in which the rotation angle of the image with respect to is stored, a computer that corrects the rotation angle according to the display mode based on the data stored in the first or second storage unit, and the computer. And a display means for displaying an image corrected by the method. 5. The correction of the imaging system by the computer based on a magnification of a TEM image with respect to a rotation angle stored in the first storage means and a current value flowing through each lens of the TEM imaging system. Controlling a plurality of lenses, or the computer performs a predetermined calculation based on the rotation angle stored in the second storage means, and controls the scanning means based on the result. Claim 4
A composite electron microscope as described. 6. The second storage means stores in advance a result of calculating a value to be corrected for an SEM / STEM image based on the rotation angle of the TEM image, and based on the result, stores the scanning means in the second storage means. 5. The compound electron microscope according to claim 4, wherein said compound electron microscope is controlled.