JPH0618455A - Analysis device - Google Patents

Abstract

PURPOSE:To prevent the appearance of gear backlash, and enable a rotary holder to continue rotation, regardless of a rotating direction, by providing a magnet on the rotational axis of the holder, arranging a plurality of electromagnets around the magnet and selecting the magnetic pole of each electromagnet via the control of current supplied thereto. CONSTITUTION:When a sample holder 1 is made to rotate on the operation of a motor 7, backlash appears due to the play of the engagement section of gears 3 and 6, and the mechanical structure of the motor 7. The magnetized state of each electromagnet is changed by controlling current supplied from a control section 8 to an electromagnet group. As a result, repellent and attracting forces are generated between electromagnets 5 and a magnet 4, and a clockwise rotating force is thereby generated. Thus, a force acts in a direction opposite to the rotating force of the axis 2 of the holder 1. Current supplied to the electromagnets 5 arranged around the magnet 4 is selected sequentially at every 45-degree rotation of the axis 2. According to this construction, a force opposite to the rotating direction of the axis 2 is continuously applied and, therefore, the backlash of the gears 3 and 6 can be prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analyzer using electron beams, α rays, ion beams and the like.

[0002]

2. Description of the Related Art For example, when performing RBS analysis (Rutherford backscattering analysis), H + or H
The ions of e + are taken out, accelerated by an accelerator to about 1 to 3 MeV, and collided with the sample in the analysis chamber. At this time, if the crystal axis of the sample coincides with the incident axis of ions, the incident ion beam passes through between the crystal atoms. This phenomenon is called the channeling phenomenon. This phenomenon reduces the backscattered ions. Therefore, the crystallinity of the sample can be evaluated by measuring the reduction rate of backscattered ions.

By the way, in order to evaluate the crystallinity of a sample, the incident angle between the incident ion beam and the sample must be changed with high precision, so that a sample holder for holding the sample is provided in the analysis chamber. Has been
By rotating this sample holder, the incident angle between the incident ion beam and the sample is changed.

Another example of analysis is analysis by electron beam diffraction, which is used for the purpose of monitoring the growth state of crystals when a thin film is formed on the sample surface. As shown in FIG. 6, in order to form a film on the surface of the sample 58 in the vacuum chamber 51, the sample 58 is irradiated with the molecular beam from the evaporation sources 52 and 53. Then, in order to monitor the crystal growth state of this thin film, an electron beam is irradiated from the electron gun 56 onto the surface of the sample 58, and the diffracted / reflected electron beam diffracted or reflected by the thin film forming surface is captured by the fluorescent screen 57, and the A periodic change in the light intensity of the brightest spot in the beam pattern appearing on the light screen 57 is observed. Based on this light intensity, the molecular beam irradiation is controlled to obtain a uniform film thickness, and the shutter 5
4, 55 controls the crystal growth of the thin film.

In order to stack a thin film on the surface of the sample 58, the sample 58 is automatically rotated to collect diffraction intensity data at regular intervals. In this case, in order to measure the diffraction intensity at the same position of the sample a plurality of times, the rotating operation of the sample 46 must be reproducible and can be accurately rotated.

By the way, when performing the above-mentioned analysis, the sample must be rotated in all cases, but this rotating operation requires accuracy and reproducibility, and the sample must be rotated without causing backlash. .

Therefore, backlash is prevented by the conventional sample stage shown in FIG. That is, by holding the sample in the sample holder 31 and rotating the motor 37, the gear 35 rotates, the power is transmitted to the gear 32, and the rotation shaft 33 rotates, so that the sample on the sample holder 31 also rotates. However, since one end of the winding spring 34 is fixed to the rotating shaft 33 and the other end of the winding spring 34 is fixed to a place other than the power portion in the drawing, the winding spring 34 is Backlash can be prevented by utilizing the force applied to the rotating shaft 33.

FIG. 5 is a plan view of the spring portion of the sample stage of FIG. When the rotating shaft 33 rotates counterclockwise, the force of the winding spring 34 acts in the direction opposite to the rotating direction of the rotating shaft 33, so backlash can be prevented.

[0009]

However, in the above-mentioned conventional method, since the range of use of the coil spring is limited, the sample holder cannot be continuously rotated many times in the same direction for analysis. . In addition, backlash can be prevented when the sample holder is rotated in the direction opposite to the direction of the force of the coil spring, but when the sample holder is rotated in the same direction as the direction of the force of the coil spring, the backlash can be prevented. Rush can be prevented to some extent, but its effect is rather low, and the rotation direction of the sample holder is also limited.

The present invention solves the above-mentioned conventional problems, and includes a sample stage which prevents backlash and can perform many rotations without limitation regardless of the rotation direction of the rotation axis of the sample holder. An object is to provide an analyzer.

[0011]

In order to achieve the above object, an analyzer according to the present invention is an apparatus for performing analysis by rotating a sample holder for holding a sample, in which a magnet provided on a rotating shaft of the sample holder is used. A sample having a plurality of electromagnets arranged around the magnet, and capable of generating a force in a direction opposite to the rotation of the rotating shaft by controlling the current flowing through the electromagnet in synchronization with the rotation It features a stage.

[0012]

A magnet is provided on the rotary shaft of the sample holder, and a plurality of electromagnets are arranged so as to surround the magnet so as to attract or repel the magnetic poles of the magnet provided on the rotary shaft. In addition, by switching a part of the magnetic poles of the plurality of electromagnets, a force opposite to the rotation direction of the rotary shaft can be continuously applied.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic view of a sample stage of an analyzer of the present invention, and FIG. 2 is a plan view of a magnet part of the sample stage of the present invention.

A sample holder rotating shaft 2 is formed on the sample holder 1, and the sample holder rotating shaft 2 is provided with a gear 3 and a magnet 4. The gear 6 is attached so as to mesh with the gear 3, and the rotation shaft of the gear 6 is directly connected to the motor 7. Further, a plurality of electromagnets 5 are arranged around the magnet 4, and each electromagnet is connected to the control unit 8 in order to control the current flowing through these electromagnets 5. FIG. 2 is a plan view of the magnet part,
As shown in this figure, a total of eight electromagnets 5 are arranged in a circle around the magnet 4. And sample holder 1
The substrate or sample is held on top for analysis.

Next, the operation will be described. When performing analysis such as electron diffraction, the sample is held by the sample holder 1 and the sample holder 1 is rotated by the motor 7 while irradiating the electron beam. At this time, backlash occurs due to the play of the meshing portions of the gears 3 and 6 and the mechanical mechanism of the motor 7 itself.

Therefore, when the sample holder rotating shaft 2 is about to rotate in the direction of the arrow in FIG. 2, the current flowing through the electromagnet B and the electromagnet H is controlled from the control section 8 to control the electromagnet B and the electromagnet B facing the magnet 4. The magnetic pole portion of the electromagnet H is made to be the N pole, and the electric currents flowing to the electromagnet D and the electromagnet F are controlled so that the magnetic pole portions of the electromagnet B and the electromagnet H facing the magnet 3 side become the S pole. To do. At this time, electromagnet A,
No current flows in C, E, and G. Then N of magnet 3
The pole repels the N pole of electromagnet B, attracts the S pole of electromagnet D, and the S pole of magnet 3 repels the S pole of electromagnet F,
Since it attracts the N pole of the electromagnet H, a force opposite to the drive rotation direction indicated by the arrow of the sample holder rotation shaft 2 in FIG. 2 acts.

FIG. 3 shows the state in which the sample holder rotating shaft 2 is rotated in the direction of the arrow 45 degrees from the state of FIG. 2 while the force in the opposite direction is applied.

The magnetized state of each electromagnet is changed by controlling the current flowing from the control unit 8 to the electromagnets A to H.
No current is passed through the electromagnets B, D, F, and H. Then, an electric current is caused to flow so that the magnetic poles of the electromagnets A and G facing the magnet 4 become N poles, and the electromagnet C facing the magnet 4 side,
A current is passed so that the magnetic pole of E becomes the S pole.

The north pole of the magnet 4 repels the north pole of the electromagnet A and attracts the south pole of the electromagnet C, and the south pole of the magnet 4 is
Since it repels the south pole of the electromagnet E and attracts the north pole of the electromagnet G, a clockwise force is generated.

Therefore, also in this case, a force in the direction opposite to the force in the direction of the arrow about which the sample holder rotation shaft 2 is about to rotate acts.

By the method described above, the sample holder rotary shaft 2 is switched by successively switching the currents flowing through the electromagnets A to H arranged around the magnet 4 as the sample holder rotary shaft 2 rotates by 45 degrees. Since a force in the direction opposite to the rotation direction of is continuously applied, backlash can be prevented.

Not only when the sample holder rotating shaft 2 rotates counterclockwise, but also when rotating clockwise, the current flowing through the electromagnet is controlled in the same manner as in the above-described method so that the sample holder rotating shaft 2 is rotated counterclockwise. It is also possible to apply a force in the clockwise direction to prevent backlash.

In the above embodiment, the magnet 4 may be either a permanent magnet or an electromagnet. Although the number of electromagnets is eight, the number is not limited to eight, and the number may be increased or decreased. Then, among the plurality of electromagnets, the electromagnets that pass a current for magnetizing and the electromagnets that do not pass a current are controlled so as to alternate, but the method is not limited to this method, and the magnets are magnetized to the N pole. The number of electromagnets and the number of electromagnets magnetized to the S pole may be increased or decreased, or may be arranged continuously.

Further, not only by switching the direction of the current flowing through the electromagnet, but also by changing the magnitude of the current,
Since the magnetic force can be adjusted, the current value can be adjusted to the optimum value for preventing backlash according to the size of the device, the size of the arrangement radius of the electromagnets, the driving force of the motor, and the like.

In the above-mentioned embodiment, the gear 3 and the gear 6 are interposed between the motor 7 and the sample holder 1, but the gear 3 and the gear 6 may be eliminated and the motor and the sample holder may be directly connected. .

[0026]

According to the present invention, a magnet is provided on the rotating shaft of the sample holder, and a plurality of electromagnets are arranged around the magnet.
By controlling the current flowing through the electromagnet, it is possible to continue to apply a force in the direction opposite to the direction of rotation of the rotating shaft.
Backlash can be prevented, and regardless of the rotating direction of the rotating shaft, many rotations can be performed without limitation, so continuous analysis and film formation can be performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a sample stage of an analyzer according to an embodiment of the present invention.

FIG. 2 is a plan view of a magnet portion of a sample stage which is an embodiment of the present invention.

FIG. 3 is a plan view of a magnet portion of a sample stage which is an embodiment of the present invention.

FIG. 4 is a schematic view of a conventional sample stage.

FIG. 5 is a plan view of a spring portion of a conventional sample stage.

FIG. 6 is a schematic diagram of an electron diffraction analyzer.

Claims (1)

[Claims] 1. An apparatus for performing analysis by rotating a sample holder for holding a sample, comprising: a magnet provided on a rotation shaft of the sample holder; and a plurality of electromagnets arranged around the magnet, An analyzer equipped with a sample stage capable of generating a force in a direction opposite to the rotation of the rotating shaft by controlling the current flowing through the electromagnet in synchronization with the rotation.