JPS6010272Y2 - Sample contamination prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sample contamination prevention device, particularly a sample contamination prevention device suitable for use in an electron microscope.

In electron microscopes, there are two types of sample introduction methods: a top entry method in which the sample is inserted into the gap of the objective lens from the direction of the electron beam axis, and a side entry method in which the sample is inserted from the side of the objective lens.

These sample introduction methods can be used depending on the type of sample and the purpose of observation, but it is desirable that any method be equipped with a function to prevent sample contamination.

However, normally, a cooling plate that can be used in both types is simply placed close to the sample, and therefore, there is a problem that the effect of preventing sample contamination is not sufficient.

An object of the present invention is to provide a sample contamination prevention device that can effectively prevent sample contamination in both side entry and top entry cases.

Figures 1 and 2 show an embodiment of the present invention.
1 is a wall forming a sample chamber; 2, 4 and 12 are O-rings for vacuum rails; 3 is a sample exchange device; 9 is an objective lens;
11 is an objective magnetic path.

A sample is selectively inserted into the gap of the objective lens 9 from the electron beam axis direction and from the sides of the objective lens 9.

Sample holder 5 when inserting the sample from the electron beam axis direction
is supported by a fine movement stage 6 placed on the upper surface of the objective lens 9, and its insertion into and withdrawal from the objective lens gap is performed by the sample exchange device 3.

Of course, in this case, the removal of the sample from the sample chamber to the atmosphere and vice versa is carried out through the sample exchange device 3 without breaking the vacuum in the sample chamber.

When inserting a sample into the gap of the objective lens 9 from the side of the objective lens 9, the sample stage 15 is constructed so as to penetrate the wall 1 in a vacuum-proof manner and extend from outside the vacuum into the sample chamber. The details of this point are omitted in the figure.

The cooling chip 8 has a first cooling section and a second cooling section, and is heated by an air cylinder 14 from the side of the objective lens 9 so that these cooling sections are selectively positioned in the gap of the objective lens 9. It is about to be moved.

The first cooling section is configured to surround the sample held by the sample holder 5 when it is positioned within the gap of the objective lens 9 (see Figure 1), and the second cooling section is configured to surround the sample held by the sample holder 5 when it is positioned within the gap of the objective lens 9 (see Figure 1). When positioned within the gap of the objective lens 9, it surrounds the sample supported on the sample stage 15 (see FIG. 2).

Note that 10 is a bellows for vacuum maintenance, and 7 is an inlet for a coolant such as liquid nitrogen or helium for cooling the chip 8.

The cooling chip 8 is cooled by a coolant.

Therefore, if the first cooling part is positioned within the gap of the objective lens 9 and the sample held by the sample holder 5 is also positioned within the same gap (see Figure 1), then Gas molecules floating near the sample are trapped in the first cooling section, thereby preventing contamination of the sample.

In this case, since the first cooling section is configured to surround the sample, gas molecules near the sample are effectively trapped by the first cooling section, and therefore sample contamination can be effectively prevented. be exposed.

When the second cooling section is positioned within the gap of the objective lens 9 and the sample on the sample stage 15 is also positioned within the same gap (in this case, the second cooling section and the sample stage 15 are shown in Fig. 2). (relationship as shown), floating molecules in the vicinity of the sample are trapped in the second cooling section.

In this case as well, since the sample is surrounded by the second cooling section, trapping is performed sufficiently.
Therefore, sample contamination is effectively prevented.

Whether the sample is inserted into the objective lens gap from the axial direction of the electron beam or from the side of the objective lens, a single (i.e. common It is also possible to use a fixed cooling section (1) to prevent contamination.

However, in this case, it is actually difficult to configure the cooling section so as to surround the sample.

This is because in order to introduce a sample, the side of the cooling section in the sample introduction direction must be opened, but since the sample introduction direction is different for the top entry set and the side entry set, the cooling section is configured to surround the sample. This is because it is practically difficult to do so.

On the other hand, as in the embodiment described above, the first.
If the second cooling section is selectively used, the open portion of each cooling section can be reduced, and therefore a configuration can be created that surrounds the sample.

Therefore, sample contamination can be effectively prevented.

As is clear from the above explanation, according to the present invention, sample contamination can be effectively prevented in both side entry and top entry cases, and its practical effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a sample contamination prevention device showing one embodiment based on the present invention, and FIG. 2 is a perspective view for explaining the relationship between a cooling chip and a sample stage. 5... Sample holder, 8... Cooling chip, 9... Objective lens, 15... Sample stage.

Claims (1)

[Scope of utility model registration request] In a sample contamination prevention device for preventing contamination of a sample selectively inserted into a gap of an objective lens from an electron beam axial direction and from a side of the objective lens, first and second
a cooling chip having a cooling section, the cooling chip being movable from the side of the objective lens so that the first and second cooling sections are selectively inserted into the gap; The first cooling section is configured to surround the sample when the sample is inserted into the gap from the axial direction of the electron beam, and the second cooling section is configured to surround the sample when the sample is inserted from the side of the objective lens. A sample contamination prevention device configured to surround the sample when inserted into the gap.