JPH0426043A - Image recording electron microscope - Google Patents

Abstract

PURPOSE:To obtain a high resolution image with a small-sized electron microscope with a sufficient magnification by furnishing a photo-receiving part consisting of a solid image pickup element below electron lenses. CONSTITUTION:In an image recording electron microscope 1, in which an electron beam from an electron source 2 penetrates a specimen 4 and the image enlarged by electron lenses 5, 6 is observed ocularly or recorded through a fluorescent plate 7. Therein a photo-receiving part 10 consisting of a solid image pickup element receiving the image on this fluorescent plate 7 or electron beam of the image enlarged is provided under the electron lenses 5, 6. For ex., a CCD (electric charge coupling element) as the solid image pickup element is separated for the purpose of small-sized construction and enhancement of the operating easiness, located under the electron lenses 5, 6, and connected with another photo-receiving part 10, or otherwise the image of the fluorescent plate 7 is changed 90 deg. and connected with photo-receiving part 10 positioned horizontally (or CCD solely). This enables constructing in a small size, and a sufficient magnification is given, and an image with high resolution and high sensitivity can be obtained.

Description

[Detailed Description of the Invention] [Summary] Regarding an image recording electron microscope that records an image of a sample to be observed with an electron microscope, the purpose is to obtain an image with a small size and sufficient image magnification and high resolution. In an image recording electron microscope that passes through a sample and visually observes or records an image magnified by an electron lens through a fluorescent screen, from a solid-state image sensor that receives the electron beam of the magnified image or the image on the fluorescent screen. A light receiving section is provided below the electronic lens.

[Industrial application field]

The present invention relates to an image recording electron microscope that records an image of a sample observed with an electron microscope.

When observing a sample with an electron microscope, it is common practice to record the observed image. Such electron microscopes have built-in image recording devices, and are desired to be miniaturized, as well as to record images with high resolution.

[Conventional technology]

FIG. 7 shows a schematic diagram of a conventional image recording electron microscope. In the image recording electron microscope 30 shown in FIG. 7, an electron beam emitted from an electron gun 31 is accelerated by an electron accelerator 32 and passes through a sample 33. The electron beam transmitted through the sample 33 is amplified by an objective electron lens 34, passes through an intermediate projection electron lens 35 and a rotatable fluorescent screen 36, and is sent to a still camera room 37 where an image of the sample 33 is recorded on film. An image is displayed on a monitor by a television light receiving section 38 such as a photoconductive film or a silicon semiconductor image pickup tube. When observing the sample 33 directly, the fluorescent screen 36 is rotated from a horizontal position toward the window 39, and the image projected on the fluorescent screen 36 is directly observed through the window 39.

In this case, no photographing or monitoring is performed.

On the other hand, when monitoring the sample 33, without using the television camera 38, a CCD (charge-coupled device) light receiving section may be inserted in the optical path between the objective electron lens 34 and the intermediate projection electron I/lens 5 when necessary. is also being carried out. That is, below the objective electron lens 34, there is a fluorescent screen, a condensing lens, and a C
The CD light receiving section is integrated into and taken out of the optical path.

[Problem to be solved by the invention]

However, the television light receiving section 38 as described above is large;
Moreover, since it is generally mounted at the bottom of an electron microscope, it may obstruct visual observation. Further, when using a CCD light receiving section, since the CCD light receiving section is interposed in an electronic lens, there is a problem that sufficient image magnification cannot be obtained since the image is not enlarged, and the resolution is also insufficient.

SUMMARY OF THE INVENTION The present invention was made in view of the above problems, and an object of the present invention is to provide an image recording electron microscope that is compact and obtains high-resolution images with sufficient image magnification.

[Means to solve the problem]

The above problem involves transmitting an electron beam from an electron source through a sample,
In an image recording electron microscope in which an image magnified by an electron lens is visually observed or recorded through a fluorescent screen, a light receiving section made of a solid-state image sensor that receives the electron beam of the magnified image or the image on the fluorescent screen is provided as described above. This problem can be solved by installing it below the electronic lens and further reducing its size to improve operability. More specifically, for example, a CCD used as a solid-state image sensor is separated, and only this is provided below the electron lens and connected to another light receiving section. Another example is the case where the image of the fluorescent screen is changed by 90 degrees and connected to a horizontally located light receiving section (or only a CCD). Further, a solid-state image sensor is provided solidly or movably below the electron lens or above the fluorescent screen. Furthermore, the solid-state image sensor and the fluorescent screen are provided in contact with each other.

[Effect]

As mentioned above, a light receiving section made of a solid-state image sensor is provided below the electronic lens. That is, since the light-receiving section is composed of a solid-state image sensor, it is possible to downsize the electron microscope as a whole compared to a television light-receiving section.

Further, the light receiving section is provided below the electronic lens,
The magnified image of the electron beam is received directly or as an image on a fluorescent screen. Thereby, it is possible to obtain a sufficient image magnification and also to obtain an image with high resolution and high sensitivity.

〔Example〕

FIG. 1 shows a schematic configuration diagram of a first embodiment of the present invention. In the image recording electron microscope l in FIG.
An electron beam irradiated from an electron gun is accelerated by an electron accelerator 3 and passes through a sample 4. The electron beam transmitted through the sample 4 is amplified by an objective electron lens 5, and an image of the sample 4 is recorded on a film in a still camera room 8 via an intermediate projection electron lens 6 and a rotatable fluorescent screen 7. When the second fluorescent screen 7 is rotated from a horizontal position so that its surfaces face each other in the direction of the window 9, an electronic beam or image is converted onto the fluorescent screen 7, which can be visually observed through the window 9.

On the other hand, a light receiving section 10 is provided below the fluorescent screen 7 and below the still camera chamber 8. The light receiving section 10 is composed of an image fluorescent screen 11 (a 20 μm thick CdS (cadmium sulfide) fluorescent film is formed on a 10-thickness glass substrate by a coating method) and a CCD camera body 13 which is a solid-state image sensor with a lens 12 interposed therebetween. be done. Although not shown, the light receiving section 1
0 is placed in a vacuum, and the video fluorescent screen 11
shielded.

In such an image recording electron microscope 1, when visually observing, the surface of the fluorescent screen 7 becomes parallel to the surface of the window 9 due to rotation. The electron beam transmitted through the sample 4 is optically converted to form an image on the fluorescent screen 7, and this image is visually observed by an observer through the window 9. On the other hand, in the case of recording, the fluorescent screen 7 is placed in a horizontal position, and the image formed on the fluorescent screen 7 is photographed on film in the still camera room 8. In the light receiving section IO, the CCD camera main body 13 receives the light via the video fluorescent screen 11 and the lens 12, and displays it on a monitor or the like (not shown).

The light receiving unit 10 is a camera composed of a CCD, which is a solid-state imaging device, and is small, so that it does not interfere with visual observation due to its position. In addition, since the light receiving section 10 is located below the electron lens (objective electron lens 5 and intermediate projection electron lens 6) and receives the electron beam after being amplified, sufficient image magnification can be obtained for monitors, etc. I can do it. Furthermore, the light receiving section 1o is a CCD
Since the light receiving section (13a) of the camera body 13 is located in contact with the image fluorescent screen 11 and the lens 12, a highly sensitive image can be obtained.

Next, FIG. 2 shows a schematic diagram of another embodiment of the above-mentioned FIG. 1. FIG. 2 shows the light receiving section in FIG.
is provided on the side of the electron microscope 1, and a main body 13 is used for image processing.
b is placed outside. As a result, the main body of the electron microscope 1 can be made more compact.

Further, FIG. 3 shows a schematic diagram of a second embodiment of the present invention.

In FIG. 3, an image fluorescent screen 11 is installed in the vacuum still camera chamber 8 of FIG.
The lens 12 and the CCD light receiving section 13a are located at the position where the degree is changed.
It is set horizontally. Then, the image processing main body 13
b is located outside the vacuum.

Next, FIG. 4 shows a schematic diagram of a third embodiment of the present invention.

In FIG. 4, the CCD light receiving section 13a in FIG. 1 is provided at the lower part of the still camera chamber 8 via a vacuum flange 16 formed by an O-ring 15. In this case, an image is directly obtained by the electron beam without forming anything on the light receiving surface of the CCD light receiving section 13a. This results in high-resolution images.

In the CCD light-receiving section 13a of FIG. 4, the light-receiving surface thereof may be coated with fluorescent CdS, or the light may be directly converted into light just before it enters the light-receiving surface to obtain an image. In this case, a highly sensitive image can be obtained.

Further, FIG. 5 shows a schematic diagram of a fourth embodiment of the present invention.

In FIG. 5(A), a CCD light receiving section 13a is placed above the fluorescent screen 7.
is provided, and the image processing main body 13b is provided externally. That is, the CCD light receiving section 13a is installed in the image observation space to directly receive the electron beam. On the other hand, the fifth
Figure (B) shows the CCD light receiving section 13a in Figure 5 (A).
is rotatable so that it can be moved when not being monitored and does not interfere with visual observation or photography using the still camera room 8. Note that the CCD light receiving section 13a in the fourth embodiment may directly receive the electronic beam without forming anything on the light receiving surface.
Alternatively, a dS fluorescent paint may be applied to convert the light into light and receive the light.

Next, FIG. 6 shows a schematic diagram of a fifth embodiment of the present invention.

FIG. 6(A) shows a CCD light-receiving section 13a attached to the back surface of the fluorescent screen 7, and FIG. 6(B) is a block diagram of this case. The fluorescent plate 7 is made by integrally applying the same fluorescent paint 7b on a stainless steel plate 7a and a CCD light receiving section 13a. That is, the same image that the observer sees through the window 9 is monitored. Incidentally, as shown in FIG. 6(C), the fluorescent paint 7b may be applied only on the stainless steel plate 7a. That is, the difference is whether the CCD light receiving section 13a receives the light as an electron beam or converts it into light, which is appropriately selected depending on the resolution and sensitivity.

In the first to fifth embodiments, the solid-state image sensor is a CCD, or a BBD (Buck
A similar effect can be obtained by using a charge transfer element such as Et Brigade Device.

〔Effect of the invention〕

As described above, according to the present invention, miniaturization can be achieved by providing a light receiving section made of a solid-state image pickup device that receives an enlarged image of an electron beam or an image on a fluorescent screen below an electron lens. At the same time, sufficient image magnification can be obtained, and images with high resolution and high sensitivity can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a first embodiment of the present invention, FIG. 2 is a schematic diagram of another embodiment of the present invention, and FIG. 3 is a schematic diagram of a second embodiment of the present invention. 4 5 6 7 Yes. The figure is a schematic diagram of a third embodiment of the present invention. The figure is a schematic diagram of a fourth embodiment of the present invention. The figure is a schematic diagram of a fifth embodiment of the present invention. The figure is a conventional image recording electron microscope. In the schematic diagram, 1 is an image recording electron microscope, 2 is an electron source, 3 is an electron accelerator, 4 is a sample, 5 is an objective electron lens, 6 is an intermediate projection electron lens, 7 is a fluorescent screen, and 8 is a still camera room. , 9 is a window, 10 is a light receiving section, 11 is an image fluorescent screen, 12 is a lens, and 13 is a CCD camera body. 1 Image Recording Electron Microscope Schematic Structure of the First Embodiment of the Present Invention Diagram Tube Diagram Diagram Diagram Figure 3 Schematic Structure of the First Embodiment of the Present Invention 5 (A) (C) Schematic diagram of the fifth embodiment of the present invention Figure 6 Schematic diagram of the conventional image recording electron microscope Figure 7

Claims (1)

[Claims] An image recording electron microscope in which an electron beam from an electron source (2) passes through a sample, and an image magnified by an electron lens (5, 6) is visually observed or recorded via a fluorescent screen (7). A light receiving unit (10) made of a solid-state image sensor that receives the electron beam of the magnified image or the image on the fluorescent screen (7) is provided below the electron lens (5, 6). Image recording electron microscope.