JPS6328519Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is an energy dispersive X-ray detector (EDS)
The present invention relates to an improvement of a specimen device in an electron microscope equipped with an electron microscope.

Recent electron microscopes are now capable of not only observing the morphology of samples, but also performing various types of analysis simultaneously. X-ray analysis is a typical example, and its use is rapidly expanding as the performance of EDS improves.

FIG. 1 is a cross-sectional view showing the main parts of an electron microscope equipped with an EDS, and numeral 1 indicates the upper magnetic pole piece of the objective lens, and 2 indicates the lower magnetic pole piece of the objective lens. 3 is a sample stage;
It is inserted between the two magnetic pole pieces 1 and 2 in a direction perpendicular to the optical axis Z, that is, in the X-axis direction. Although this stage is not shown, it is arbitrarily slightly moved within a plane (XY plane) perpendicular to the optical axis Z by a drive mechanism placed outside the lens barrel of the microscope. Further, the stage can rotate through a certain angle about its axis X, thereby imparting an inclination to the sample. A sample holder 4 made of a light material such as beryllium is held near the optical axis of the stage 3. This holder is attached to the stage by an axis (not shown) perpendicular to the plane of the paper, and can be rotated around the center of this axis (i.e., the Y axis) so that the sample can be tilted at any angle. That's good. A sample 5 is fixed to the center of the holder via a collar 6 by a spring member 7. As shown in an enlarged view of an example in FIG. 2, this spring member is a snap spring whose outer diameter is larger than the insertion hole 4a of the holder. As the outer diameter becomes smaller than the insertion hole, it can be pushed into the insertion hole, and when the tips of the tweezers are removed, both ends 7
a and 7b are opened and fixed in the insertion holes. Since the spring member is handled in this manner, it is made of a strong elastic body made of a heavy element, such as phosphor bronze.

8 is the EDS, which is connected to a cooler outside the lens barrel. 9 is an entrance slit placed in front of it.

In such a configuration, the specimen stage 3 is moved or rotated to arbitrarily select the field of view and tilt angle of the specimen to observe the electron microscope image, and the X of the specimen at the desired location and tilt angle is observed. line analysis
Although this is done using EDS, there is a problem in that X-rays from sources other than the sample enter the EDS, causing ghosts to appear in the analytical data. That is, as mentioned above, in the conventional sample apparatus, the sample 5 is fixed by the collar 6 and the spring member 7, but these, especially the spring member, are made of a metal with a high atomic number and are not suitable for the electron beam path. Since they face each other, they are hit by electron beams and scattered X-rays, resulting in a large amount of X-rays being generated. In this case, if the spring member 7 etc. are far away from the sample 5, the X-rays will not enter the EDS 8, but as can be seen from FIG.
The spring member is located immediately behind the sample when viewed from the side, and therefore a large amount of X-rays generated from the member are detected by the EDS as noise.

Furthermore, since there is no guide when inserting the spring member into the insertion hole, it is difficult to insert the spring member into the insertion hole.

The present invention aims to solve the above-mentioned drawbacks and provide a sample device for an electron microscope equipped with an X-ray detector that can eliminate ghosts during X-ray analysis and facilitate insertion of a spring member. .

Therefore, the present invention is equipped with an energy-dispersive X-ray detector above or to the side of the objective lens, and a sample stage is inserted between the magnetic pole pieces of the objective lens in a direction perpendicular to the optical axis. A sample holder main body having an electron beam passage hole 11 is held, and a sample contact surface 12 perpendicular to the direction of the hole is formed inside the hole, and the diameter of the hole is oriented toward the contact surface. A tapered surface 13 was formed on the side surface of the hole 11b on the lower side of the contact surface by continuously increasing the diameter to the diameter of the contact surface. The ring-shaped spring member 7 communicates with the upper part 11a of the hole through an opening formed in the hole, and receives an upward force from the tapered surface when it is inserted into the lower hole part and tries to return to its natural diameter. In the device for pressing and fixing the sample 5 against the abutment surface using the spring member, there is provided a flange 10a disposed between the spring member and the sample, and a lower side of the sample holder main body from the flange. A cylindrical portion 10b extending downward beyond the end surface 14 and disposed inside the spring member so as to cover the spring member, and a shield body 10 made of carbon or a conductive member having an atomic number lower than that. It is characterized by the fact that it has been established.

An embodiment of the present invention will be described below, including a more detailed explanation of the configuration.

In the figure, 4 is a holder body, 11 is an electron beam passing hole bored in the holder body 4, and a sample contacting surface 12 is formed inside the hole 11, which is perpendicular to the direction of the hole. By continuously increasing the diameter of the hole toward the contact surface up to the diameter of the contact surface, a tapered surface 1 is formed on the side surface of the hole 11b on the lower side of the contact surface.
3 is formed, and the portion of the hole below the corresponding contact surface communicates with the upper portion 11a of the hole through an opening formed in the contact surface. Reference numeral 7 designates the aforementioned ring-shaped spring member which is inserted into the lower hole portion and receives an upward force from the tapered surface in an attempt to return to its natural diameter. Reference numeral 10 denotes a flange 10a disposed between the spring member and the sample, and a flange 10a that extends downward from the flange beyond the lower end surface 14 of the sample holder main body and is disposed inside the spring member so as to cover it. This is a shield body consisting of a cylindrical portion 10b. The shield body 10 is made of a conductive material having an atomic number lower than carbon, such as carbon or metal beryllium.

In this configuration, the sample holder body 4
The sample 5 is then inserted into the hole 11b.
Then, the shield body 10 is inserted into the hole 11b with the flange portion 10a first.
The tip of the cylindrical portion 10b of the holder body 4 is protruding from the end surface 14 of the holder body 4. The spring member 7 is then hooked onto this protruding portion, and the spring member 7 is inserted into the hole 11b while pinching the bent portions 7a and 7b at both ends with the tips of tweezers so as to tighten the cylindrical portion 10b.
is guided by the tapered surface 13 to the contact surface 12
Then, the specimen 5 is moved to the side, and the specimen 5 is pressed against the contact surface 12 via the flange 10a of the shield body 10, thereby fixing the specimen in place. Then, as shown in Fig. 3, the specimen stage is set in the specimen chamber, and the specimen is observed.

With this configuration, the spring member 7 is completely covered by the shield body 10,
Since it is not exposed to electron beams or scattered X-rays, even if the spring member is made of a heavy metal such as phosphor bronze, it will hardly generate X-rays.

By the way, in the present invention, the shield body 10 is
It comes to face the EDS, but since this shield body is made of a material with a low atomic number below carbon, the wavelength of the generated X-rays is long and is hardly detected by the EDS. Therefore, noise during analysis is extremely reduced, and ghosts do not occur as in the past.

Further, according to the present invention described above, since the spring member can be guided by the cylindrical portion 10b of the shield body 10 and inserted into the hole 11b, it becomes easy to insert the spring member 7 into the hole 11b.

In the above-mentioned embodiment, an example in which the present invention is applied to an electron microscope having an EDS above the objective lens is described in detail, but the present invention may also be applied to an electron microscope having an EDS inserted from the side of the objective lens. is equally applicable.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main part of a conventional device, FIG. 2 is an enlarged view of a part thereof, and FIG. 3 is a sectional view of the main part showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Upper magnetic pole piece of objective lens, 2... Lower magnetic pole piece of objective lens, 3... Sample stage, 4... Sample holder body, 5... Sample, 7... Spring member, 8... EDS, 10 ...shield body, 10a
. . . Flange portion, 10b .

Claims (1)

[Scope of utility model registration request] An energy dispersive X-ray detector is provided above or in the lateral direction of the objective lens, and a sample stage is inserted between the magnetic pole pieces of the objective lens in a direction perpendicular to the optical axis. A sample holder main body having a diameter is held, and a sample abutting surface 12 is formed inside the hole, which is perpendicular to the direction of the hole, and the diameter of the hole is directed toward the abutting surface. By increasing the diameter of the contact surface, a tapered surface 13 is formed on the side surface of the hole 11b on the lower side of the contact surface.
is formed, and the lower part of the hole on the corresponding contact surface is connected to the upper part 1 of the hole by the opening formed in the contact surface.
1a, and includes a ring-shaped spring member 7 that is inserted into the lower hole portion and receives an upward force from the tapered surface in an attempt to return to its natural diameter. In a device for pressing and fixing against a contact surface, a flange portion 10 disposed between the spring member and the sample.
a and a cylindrical portion 10b that extends downward from the collar portion beyond the lower end surface 14 of the sample holder body and is disposed inside the spring member so as to cover the spring member, and is made of carbon or a material with an atomic number lower than that. A sample device for an electron microscope equipped with an X-ray detector, characterized in that a shield body 10 made of a conductive member is provided.