JPS6378441A - Vibration-proof supporting device for electron microscope or the like - Google Patents

Abstract

PURPOSE:To protect against disturbance vibrations by selecting a vibration-proof bed so that it is added to a microscope body and has a load to set the position of its center of gravity in a sample chamber and the vertical force applied from the vibration-proof bed to the microscope body faces the position of the center of gravity according to its shape, structure, and layout. CONSTITUTION:The shape, structure, and layout of a vibration-proof bed 6 are selected so that the center of gravity G of the whole microscope body is located at the position of a sample fine adjustment device 3, preferably a sample, and the vertical force F applied from the vibration-proof bed 6 to the microscope body faces the position of the center of gravity. The position of the center of gravity G can be set as desired by adjusting the size and position of a load 8. When the vibration-proof bed 6 is thus constituted, even if disturbance vibrations occur, locking occurs around the center of gravity, and the sample fine adjustment device 3 has very little acceleration, thus the displacement of the sample fine adjustment device 3 due to locking can be made minimum.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a vibration-proof support device for an electron microscope or the like.

[Conventional technology]

As shown in Japanese Utility Model Publication No. 50-30927, a conventional anti-vibration device for a scanning electron microscope (hereinafter referred to as SEM) includes a plurality of anti-vibration devices installed at the bottom of a load plate provided at the bottom of a sample chamber. It was known that the shaking table was placed horizontally.

In this supported state, when external vibrations occur and vibrate vertically or horizontally on the floor, the sample chamber on the vibration isolating table, the sample fine movement device, the electron optical system, etc. are subject to locking. This resulted in the sample fine movement device being displaced relative to the electron beam, resulting in a disadvantage that it became vulnerable to external vibrations.

[Problem that the invention seeks to solve]

The above conventional technology has the disadvantage that when the mirror body is subjected to rocking, the sample fine movement device receives acceleration due to rocking, making it easy for the sample fine movement device to deform and displace or cause image disturbances due to vibration. .

The purpose of the present invention is to eliminate the above-mentioned drawbacks, and to provide a vibration isolation system for electron microscopes, etc., which does not cause acceleration on the sample stage even if a rocking motion occurs due to disturbance vibration in one body part, and which is strong against disturbance vibration. The object of the present invention is to provide a support device.

[Means for solving problems]

The purpose of the above is to position the center of gravity of the mirror body near the sample fine movement device and to receive the load on the vibration isolating table.

That is, this is achieved by selecting the structure, shape, and arrangement of the vibration isolation table so that the Ts rectangular direction that the mirror body receives from the vibration isolation table faces the center of gravity of the sample fine movement device.

[Effect]

When external vibration is applied, the mirror on the vibration isolating table not only vibrates in the horizontal plane and vertical direction, but also causes a so-called rocking phenomenon in which it attempts to rotate about one center of gravity. The shape and structure of the anti-vibration table is such that the center of gravity is located near the center of gravity, and the vertical force that the mirror receives from the anti-vibration table reflects the position of the center of gravity.

When the arrangement is selected, rocking is performed using the sample fine movement device as a fulcrum, and the amount of acceleration that the sample fine movement device receives is minimized, so the displacement and deformation of the sample fine movement device due to disturbance is minimized.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

Electron optical system 1. Sample chamber 2. Sample micro-motion bag v! 13, the entire body including the exhaust system 9 etc. is called the RG body.

The load of this mirror body is carried by a load plate 5, which is supported on a pedestal 7 via four vibration isolating stands 6 arranged at equal angles around the axis of the mirror body.

This vibration isolation table 6 is for preventing external vibrations from the floor (not shown) from being transmitted to the mirror body section via the pedestal 7.

By the way, floor vibration is generally a low frequency vibration of several Hz to 10011 Hz, and if the acceleration of the vibration is large, the propagation to the m-body cannot be completely blocked by the above-described configuration.

Especially in the case of floor vibration of several Hz (1 to 5 Hz).

Since the resonant frequency of the vibration isolation table 6 is usually about 2 to 4 Hz, the vibration isolation effect does not disappear, but rather increases.

The part of the mirror body that is most sensitive to external vibrations is the sample micro-movement bag EE3. Normally, with the sample 4 placed on it, the sample 4 is moved within the XY plane and in the Z direction (optical axis direction), rotated twice, and tilted. Since the structure is such that it can be exposed to vibrations from all directions, it is inevitable that the structure will be weak against vibrations.

However, when the load plate 5 vibrates due to disturbance vibration,
In addition to the movement of the m body in the horizontal plane and the movement in one orthogonal direction, the mirror body causes rotational movement (locking).

The allowable value of the relative displacement of the sample 4 with respect to the electron beam varies depending on the resolution of the device, but if the device has a resolution of 2 nm, the allowable value is 2 nm or less.

In this embodiment, the sample fine movement device 3. As much as possible, the center of gravity G of the entire mirror should be located at the position of the sample 4, and
The shape of the vibration isolator 6 is such that the vertical force F that the mirror body receives from the vibration isolator 6 is directed toward the center of gravity.

The position of the zero center of gravity G, which selects the structure and arrangement, can be set as desired by adjusting the size and position of the load 8. When the vibration isolation table 6 is configured in this way,
Even when disturbance vibration occurs.

Locking will occur around the center of gravity,
Since almost no acceleration is applied to the sample fine movement device 3,
Specimen fine movement device 3 by rocking! , the displacement can be minimized.

In the above, the vibration isolating tables 6 are arranged at equal intervals around the axis of the mirror body.
However, the number can be changed arbitrarily, and furthermore, all the vibration isolation tables can be connected in a ring shape. It goes without saying that the present invention can also be applied to microscopes other than the scanning type and similar devices.

〔Effect of the invention〕

As described above, according to the present invention, even if the mirror body is shaken due to external vibration, the acceleration to the specimen fine movement device due to rocking can be minimized, so the device can be made resistant to external vibration, and This has the effect of preventing deformation and displacement of the sample fine movement device due to vibrations, and also preventing image disturbances caused by external vibrations.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Electron optical system, 2... Sample chamber, 3... Sample micro-motion bag device, 4... Sample, 5... Load plate, 6... Vibration isolation stand, 7... Frame .

Claims (1)

[Claims] 1. A load plate is fixed to a mirror body of an electron microscope, etc., including an electron optical system, a sample chamber, an exhaust system, etc., and the load plate is placed on a vibration isolating stand fixed on a mount. A vibration isolating support device for an electron microscope, etc., which supports a mirror body with a load attached to the mirror body to set the center of gravity of the mirror body within the sample chamber, and which has a load that is attached to the mirror body to set the center of gravity of the mirror body within the sample chamber. A vibration isolation support device for an electron microscope, etc., characterized in that the arrangement is selected such that the vertical force exerted on the mirror body from the vibration isolation table is directed toward the center of gravity. 2. A vibration-proof support device for an electron microscope, etc., as set forth in claim 1, wherein the sample chamber includes a sample fine movement device, and the center of gravity of the mirror body is located within or near the sample fine movement device. . 3. The vibration isolating tables are arranged at equal intervals around the axis of the mirror body.
Anti-vibration support device for electron microscopes, etc. as described in Section 1.