JP2003263969A - Sample holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample holder for an electron microscope which is operated in such a way that a voltage is applied to a sample or electrical sign is taken out from the sample for observation, which enables easy exchanging work and realizing a thinner thickness of the sample holder by retaining good electrical connection when the sample is exchanged, and enables avoiding drift of an image under observation caused by accumulation of charge on an insulator being irradiated by the electron beams. <P>SOLUTION: Common terminals for press fixing of the sample and for voltage applying are used. One side of a sample table is coated with an insulating material, and the electron beam is irradiated from the position facing the coated side of the sample table. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample holder for holding a sample in a passage of an electron beam emitted from a charged particle beam source (electron gun, ion gun, etc.) such as an electron microscope for observing a sample, , A sample holder for observing a sample while applying a voltage or taking out an electric signal, or thereafter.

[0002]

2. Description of the Related Art In a transmission electron microscope, it is sometimes desired to observe a sample such as a movement of a lattice defect of a semiconductor while or immediately after an electrical stimulus is applied to the sample.

Conventionally, wiring for voltage application has been performed by directly soldering the sample itself. However, the size of the sample may be as small as several mm, and skill is required to perform soldering, and the electrical connection state varies depending on the sample exchange due to the soldering state. When exchanging the sample, the solder had to be removed and wiring to a new sample had to be performed again, and it took time to exchange the sample.

Further, conventionally, an insulator is sandwiched between the sample and the sample table in order to insulate the sample from the sample table. However, if the insulator is sandwiched between the sample and the sample table, the sample holder becomes thick. The sample holder may be installed at a distance of a few mm from the pole piece of the objective lens, and particularly in the case of a tilted sample stand, tilting the thick sample stand interferes with the pole piece of the objective lens. Sometimes. A thick sample stand is more
The angle that can be tilted was small.

Further, conventionally, the sample is housed in a recess provided in a sample base made of an insulator, and the sample is covered with a donut-shaped plate made of an insulating part and a conductive part, and a voltage is applied to the cover by a terminal. Was going on. However, if a concave portion is provided on the sample stage, the thickness of the sample stage increases, and if it is tilted at a large angle, it may interfere with the pole piece of the objective lens. Contact resistance was generated through the conductive part of the cover. Further, when the sample stage, which is an insulator, is directly irradiated with electrons, electric charges are accumulated, which causes the observed image to drift.

[0006]

The problem to be solved by the present invention is to provide a good electrical connection when exchanging a sample in an electron microscope for applying a voltage to the sample or extracting an electrical signal from the sample for observation. Therefore, it is an object of the present invention to realize a sample holder that can be easily replaced and can reduce the thickness of the sample holder. Further, the problem to be solved by the present invention is to prevent the observed image from drifting by irradiating an insulator with an electron beam to accumulate charges.

[0007]

The present invention is provided with a sample table for holding a sample and a pressing member for pressing the sample to the sample table, and a pressing member insulated from the sample table is attached to the sample. The feature is that it also serves as a terminal to be electrically connected.

Further, according to the present invention, in a sample holder for applying a voltage to a sample in a direction parallel to the sample table or for extracting an electric signal, a portion of the sample table that comes into contact with the sample is insulation-coated, and an electron beam is emitted. It is characterized in that irradiation is performed from the opposite side of the surface of the sample table on which the insulating coating is processed.

Further, according to the present invention, in a sample holder for applying a voltage to a sample in a direction perpendicular to a sample table or for extracting an electric signal, one electrode is a sample table and the other electrode is a pressing member. Is characterized by.

Further, the present invention is characterized in that the above-mentioned voltage application method is used in a sample holder in which a sample stage is tilted at an arbitrary angle around an axis passing through the sample.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of a transmission electron microscope. An objective lens magnetic pole piece 2 is arranged inside the lens barrel 1 maintained in a vacuum, and a sample holder 3 holding a sample at its tip is inserted into the gap between the objective lens magnetic pole pieces 2 from the outside of the lens barrel. A portion of the lens barrel 1 through which the sample holder 3 penetrates is provided with a sample moving mechanism 4 that holds the sample holder 3 in a removable manner and moves the sample.

FIG. 2 is a perspective view of the tip portion of the sample holder of the present invention. A sample underframe 7 is installed at the tip of the sample holder 3, and a sample underframe opening 7a is formed in a portion where the electron beams 5 intersect at right angles. The sample table 6 is supported in the sample table frame opening 7 a via a sample table tilt shaft 9. The lever body 8 also has a lever body shaft 12 in the sample underframe opening 7a.
Is supported via the sample base 6, and one end is connected to the sample table 6 so that the connecting portion is movable and rotatable, and the other end is a lever contact member installed inside the sample underframe support member 11. 1
It is in contact with 3. The sample table tension spring 10 pulls the sample table so that the lever body 8 and the lever body contact portion 13 are always in contact with each other.

In the above structure, when the lever contact member 13 is pushed in the longitudinal direction of the sample table supporting frame 7, the lever body 8 rotates about the lever axis 12 in the clockwise or counterclockwise direction. Then, the sample table 6 is tilted about the sample table tilt axis 9. As a result, the sample 14 pressed against the back surface of the sample table 6 tilts with respect to the electron beam, so that a transmission image with an arbitrary tilt angle can be observed.

FIG. 3 is a rear view of the tip portion of the sample holder when a voltage is applied in the direction parallel to the sample table 6 as seen from the direction of arrow A in FIG. FIG. 4 is a sectional view taken along line BB in FIG. The sample 14 is mounted on the sample table 6 with screws 16 and nuts 17.
It is stopped by a pair of leaf springs 15a and 15b fixed by. The leaf springs 15a and 15b are insulated from the sample table 6 by the insulating coating 18 and the insulator 20. The portion of the nut 17 in contact with the sample table 6 is also coated with an insulating coating and is insulated from the sample table 6.
The nut 17 is connected to a power source (not shown) via a sample application line 19. Therefore, the leaf spring 15 which is a conductor
The a and 15b are electrically connected to the screw 16 that is a conductor and the nut 17 that is a conductor, and serve as terminals. Since the insulating coating 18 can be controlled in the order of μm by coating such as painting or vapor deposition, the thickness of the insulating coating 18 can be coded according to the applied voltage. Therefore, it can be made as thin as a sample table to which no voltage is applied. still,
The leaf springs 15a and 15b may be elastic by installing springs on the screw portions. Insulation coating 18
In addition, when the electron beam is irradiated, electric charge is accumulated in the insulating coating 18 and causes an observed image to drift. Therefore, it is preferable to irradiate the electron beam from a surface opposite to the surface coated with the insulating coating 18.

In the above structure, by loosening the screw 16, the leaf springs 15a and 15b are brought into non-contact with the sample 14 and at the same time the conduction is lost, so that the sample 14 can be easily replaced. Replaced sample 14 with screw 16 again
By tightening, it is possible to connect to the leaf springs 15a and 15b to establish conduction.

FIG. 5 is a rear view of the tip portion of the sample holder when a voltage is applied to the sample table 6 in the vertical direction, as seen from the direction of arrow A in FIG. FIG. 6 is a sectional view taken along line CC in FIG. The sample 14 is fixed by one leaf spring 15c fixed to the sample table 6 with one screw 16 and one nut 17. Since the through hole 15d is opened in the leaf spring 15c,
The electron beam can pass through. The leaf spring 15c is insulated from the sample table 6 by the insulator 20. An insulating coating or the like is applied to a portion of the nut 17 that contacts the sample table 6. The other screw 16 and nut 17 are fixed to the sample table 6 and electrically connected to the sample table 6.

In the above structure, the sample table 6 and the sample 14 are brought to the same potential by bringing the sample table 14 into contact with the sample table 6. That is, the sample 14 is applied with a voltage in the voltage application direction 22 perpendicular to the sample table 6 with the plate spring 15c as one electrode and the sample table 6 as the other electrode. When replacing the sample 14, the screw 16 is loosened so that the leaf spring 15c can be replaced by the sample 1
The sample 14 can be easily exchanged because it is not in contact with the sample No. 4 and at the same time there is no conduction. 2 and 5, the electron beam is irradiated from the surface of the sample table 6 opposite to the surface on which the sample 14 is pressed, but the sample table of FIG. Therefore, the sample 14 may be stopped on the surface irradiated with the electron beam.

[0018]

As described above, according to the present invention, the terminal for connecting to the sample and the pressing member for pressing the sample on the sample base are made common. Therefore, wiring to the sample is easy and the sample can be exchanged in a short time, and even if the sample is exchanged, a substantially constant electrical connection state can be maintained. Also, the sample holder can be made compact,
Contact resistance is low because the pressing member that functions as a terminal is directly connected to the sample.

Further, according to the present invention, when the sample table is tilted, the sample table is thinned so that the tilting operation can be performed without any restriction.

[0020]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a transmission electron microscope barrel.

FIG. 2 is a perspective view of a tip portion of a sample holder.

FIG. 3 is a rear view of the tip end portion of the sample holder viewed from the arrow A in FIG. 2 when a voltage is applied in the direction parallel to the sample table.

FIG. 4 is a sectional view of the sample holder taken along the line BB in FIG.

5 is a rear view of the tip end portion of the sample holder viewed from the arrow A in FIG. 2 when a voltage is applied to the sample table in the vertical direction.

FIG. 6 is a sectional view of the sample holder taken along the line CC of FIG.

[Explanation of symbols]

1 lens barrel 2 Objective lens pole piece 3 Sample holder 4 Sample moving mechanism 5 electron beam 6 sample table 6a Sample table through hole 7 Sample frame 7a Sample stand frame opening 8 Leverage 9 Sample table tilt axis 10 Sample table tension spring 11 Sample underframe support member 12 lever axis 13 Lever body contact member 14 samples 15a leaf spring 15b leaf spring 15c leaf spring 16 leaf spring screw 17 leaf spring nut 18 Insulation coating 19 Sample application line 20 insulators 21 Voltage application direction 22 Voltage application direction

Claims (4)

[Claims] 1. A sample table for holding a sample and a pressing member for pressing the sample to the sample table, wherein the pressing member insulated from the sample table electrically connects to the sample. A sample holder for an electron microscope that doubles as a connecting terminal. 2. A sample holder for applying a voltage to the sample table in a direction parallel to the sample table or for extracting an electric signal, wherein an insulating coating process is applied to a portion of the sample table that contacts the sample. The sample holder for an electron microscope according to claim 1, wherein the electron beam is irradiated from a surface opposite to the surface of the sample table on which the insulating coating is processed. 3. A sample holder for applying a voltage to the sample in a direction perpendicular to the sample stage or for extracting an electrical signal, wherein one electrode is the sample stage and the other electrode is the pressing member. The sample holder for an electron microscope according to claim 1. 4. The sample holder according to claim 1, 2 or 3, wherein the sample stage is inclined at an arbitrary angle about an axis passing through the sample.