JP2000106123A - Transmission electron microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission electron microscope capable of photographing an element distribution image, similarly with a TEM image on a TEM image photographing film. SOLUTION: Electron beam 1, having intensity corresponding to the X-ray intensity data among the X-ray intensity data stored in a memory device once, is emitted from an electron gun 2 synchronously with X, Y scanning signals, and this electron beam is exposed on a film 6 for photographing. With this structure, an element distribution image can be photographed similarly to a normal TEM image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission electron microscope (hereinafter abbreviated as TEM), and more particularly to improvement of operability and photographing / recording when observing an elemental analysis image using an X-ray analyzer.

[0002]

2. Description of the Related Art In observation of a TEM image, observation of an element distribution image is usually performed using a scanning image observation apparatus having a function of scanning an electron beam. Therefore, the scanning image (secondary electron image, scanning transmission electron image, etc.) and the element distribution image were displayed on the same screen and could be observed and recorded at the same time. In Japanese Patent Application Laid-Open No. 7-302571, TEM
The image and the region where the element distribution image is to be obtained (the region where the electron beam is scanned) are traced by the electron beam, displayed on the imaging device, and the region for element distribution image observation is determined while observing the TEM image. There has been disclosed a method which enables an element distribution image to be obtained by switching to a two-dimensional scanning signal.

[0003]

However, in the above-mentioned means, a TEM image is usually recorded on a film, whereas an element distribution image cannot be recorded on a film in the same manner as a TEM image. The TEM image itself could not correspond one-to-one with the element distribution image. Also, since the TEM image and the element distribution image taken by this method are a photograph and image data, respectively, it is possible to display the region where the element analysis was performed on the TEM image, but the TEM image and the element distribution There is a problem that the distribution images do not completely correspond to each other.

It is an object of the present invention to enable an element distribution image to be photographed on a film as well as a TEM image as described above, and to use an imaging device other than a TEM image photographing device. Another object of the present invention is to provide a transmission electron microscope capable of recording an element distribution image.

[0005]

At least an irradiation lens system capable of bringing an electron beam into a spot state, and an X-ray analyzer for detecting an X-ray generated by irradiating a sample with an electron beam and performing elemental analysis. Electron beam scanning means for scanning the spotted electron beam on the sample surface in the X and Y directions;
In a transmission electron microscope equipped with a control unit for controlling the electron dose of an electron beam for irradiating a sample, the intensity of X-rays generated from the sample during electron beam scanning can be measured at electron beam scanning positions X and Y.
By storing the data in a storage device in accordance with the stored data and controlling the electron beam based on the stored data so that the electron dose at each of the X and Y positions corresponds to the stored data, an element distribution image can be obtained. A transmission electron microscope characterized by what is possible.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the principle of TEM of the present invention up to the irradiation of an electron beam 1 to a sample. The electron beam 1 emitted from the electron gun 2 is focused by the focusing lens 3 and
By adjusting the position of the beam on the sample surface or on the fluorescent screen, an arbitrary position on the surface of the sample 5 is irradiated. Usually, in the TEM image observation, the sample 5 is irradiated with an electron beam in a wide range. In the element distribution image observation, the beam is scanned like a locus 6 in a spot state where the beam is narrowed down.

FIG. 2 shows an example of a method for displaying an element distribution image in a TEM according to the present invention. The configuration is as follows. The TEM is controlled by a TEM control unit 7 such as setting of lens conditions and acceleration voltage. The control of the electron dose of the electron beam 1 is performed by controlling the bias voltage by the output from the electron gun control operational amplifier 8 connected to the bias unit of the electron gun 2. The electron gun control operational amplifier 8 is connected to the TEM control unit 7,
The output of the control operational amplifier 8 is controlled by a signal from the TEM control unit 7. Similarly, the control of the lens system such as the focusing lens 3 and the deflection system such as the alignment coil 4 is performed by outputting the output from the focusing lens control operational amplifier 9 and the alignment coil control operational amplifier 10 to a TEM.
It is controlled by a signal from the control unit 7.

A signal from the TEM control unit 7 to be output to each operational amplifier is determined based on a numerical value input to the TEM control unit 7 by an operator.
Perform image observation. The TEM is provided with an X-ray analyzer capable of outputting X and Y scanning signals and having a function of observing an element distribution image using the X and Y scanning signals. The X-ray analyzer includes an X-ray detector 11 for detecting X-rays emitted from a sample, an X-ray analyzer controller 12 for controlling the X-ray analyzer, a storage device 13 for storing observation data, and recording. It comprises a display device 14 for displaying data.

Using the TEM configured as described above,
Observation of a TEM image and an element distribution image is performed in the following procedure. First, a sample surface is irradiated with an electron beam in a spot state without changing the conditions of the imaging lens system during TEM image observation. In this state, X-rays have already been emitted from the sample 5 and X-rays have been detected by the X-ray detector 11, so that X-ray analysis is possible. In this state, X and Y scanning signals are output from the X-ray analyzer control unit 12 to the operational amplifier 10 for controlling the alignment coil. Thus, the electron beam 1 scans in the X and Y directions, and the element distribution on the sample surface can be measured and observed. At this time, X,
The data of the Y scanning signal and the X-ray intensity data at each point are temporarily stored in the storage device 13.

Next, after moving the sample 5 to a place where the beam does not hit, X-ray intensity data among the stored data is fed back to the electron gun control operational amplifier 8 via the TEM control unit 7. The TEM control unit 7 has data of an electron gun control signal for controlling the electron beam 1 to an electron dose corresponding to the X-ray intensity in advance, and stores the electron beam of the electron dose corresponding to the input X-ray intensity data. 1 can be emitted from the electron gun 2. At the same time, the X and Y scanning signal data are fed back to the alignment coil control operational amplifier 11 via the TEM control unit 7. An electron beam 1 having an intensity corresponding to the X-ray intensity data is emitted from an electron gun 2 in synchronization with the X and Y scanning signal data. Since the sample 5 has been moved to a place where the beam does not hit in advance, the electron beam 1 having an intensity corresponding to the X-ray intensity at each of the X and Y positions is irradiated onto the fluorescent plate 15. As a result, the electron beam 1 having an intensity corresponding to the element distribution image is irradiated onto the fluorescent plate. This fluorescent plate is connected to the TEM control unit 8 so that the electron dose of the electron beam emitted from the electron gun 2 can be measured. The TEM control unit 7 has in advance data of an optimal electron dose for exposing on a film, and applies the data obtained by multiplying the data to the data of the electron beam 1 having an intensity corresponding to the X-ray intensity. In order to feed back to the control operational amplifier 8, it is possible to irradiate the electron beam 1 having an intensity corresponding to the X-ray intensity at each of the X and Y positions in a time optimal for exposing the film. After the electron dose of the electron beam 1 to be irradiated is determined, the fluorescent plate 15 is moved to a place where the electron beam 1 does not hit similarly to the sample, so that the film 16 is exposed to a beam having an intensity corresponding to the element distribution image. Image is taken. Therefore, the element distribution image can be photographed in the same manner as a normal TEM image.

FIG. 3 shows an example of an element distribution image display method when a TV camera is used as a TEM image pickup device. The configuration is such that a TV camera 1 for recording and photographing a TEM image and an element distribution image instead of the film 16 of FIG.
7. Image recording device 1 for recording an image captured by a TV camera
8 and an image display device 19 for displaying an image. By using this configuration, even when a TV camera is used, the element distribution image is recorded and recorded in the same manner as a normal TEM image.
It becomes possible to shoot. Similarly, when a TEM image capturing device other than a film such as an imaging plate is used in addition to the TV camera, a TEM image and an element distribution image can be recorded and photographed using the same image capturing device.

By utilizing this, it is possible to record an element distribution image without using an imaging device other than a TEM image photographing device and a scanning image observation device in the TEM.

[0014]

As described above, according to the present invention, the following effects are achieved.

Since it is possible to observe an element distribution image using a TEM and to photograph the element distribution image on the film in the same manner as the TEM image, data corresponding to the TEM image and the element distribution image completely one-to-one. It is possible to record as. Also,
The element distribution image can be observed using a TEM having no scanning image observation device, and the element distribution image can be recorded without using an imaging device other than a TEM image photographing device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a structure of a TEM according to an embodiment of the present invention up to irradiation of a sample with an electron beam 1;

FIG. 2 is a block diagram showing an example of a method for displaying an element distribution image in a TEM according to the present invention.

FIG. 3 is a block diagram showing an example of an element distribution image display method in a TEM according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electron beam, 2 ... Electron gun, 3 ... Focusing lens, 4 ... Alignment coil, 5 ... Sample, 6 ... Beam locus, 7 ...
TEM control unit, 8: operational amplifier for controlling an electron gun, 9: operational amplifier for controlling a focusing lens, 10: operational amplifier for controlling an alignment coil, 11: X-ray detector, 12: X-ray analyzer control unit, 13: storage device, 14 ... Display device, 15 ... Fluorescent plate, 16 ... Film, 17 ... TV camera, 18 ... Image recording device, 19 ... Image display device.

Claims (1)

[Claims] At least an irradiation lens system capable of bringing an electron beam into a spot state, an X-ray analyzer for detecting X-rays generated by irradiating a sample with an electron beam and performing an elemental analysis, In a transmission electron microscope equipped with an electron beam scanning means for scanning the sampled electron beam on the sample surface in the X and Y directions and a control unit for controlling the electron dose of the sample irradiation electron beam, the electron beam is generated from the sample when scanning the electron beam. The X-ray intensity is stored in a storage device in association with the electron beam scanning positions X and Y, and the electron beam is controlled based on the stored data so that the electron dose at each X and Y position corresponds to the stored data. A transmission electron microscope characterized in that an element distribution image can be obtained by performing the following.