JPH09190791A - Charged-particle beam device having ion pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charged-particle beam device having an ion pump such that the load of the ion pump is not applied to a lens-barrel. SOLUTION: A casing 6d accommodating a cathode 6a and an anode cell 6b is placed between magnets 6c and mounted in an electron-gun chamber 5. The magnets 6c are attached to a support member 14 by screws 8a, 8d, the support member 14 is attached to a support member 10 by screws 13a, 13b, and the heavy magnets 6c are attached to a column 9 via the support members 14, 10. Thus in this device, the casing 6d is mounted in the electron gun chamber, the magnets 6c are attached to the column 9, and the casing 6d and the magnets 6c are separately fixed into place.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a charged particle beam apparatus such as a scanning electron microscope equipped with an ion pump.

[0002]

2. Description of the Related Art FIG. 1 shows a scanning electron microscope equipped with a conventional ion pump. In FIG. 1, a scanning electron microscope 4 including a sample chamber 2 and a lens barrel (housing) 3 is placed on a base plate 1, and an electron gun chamber 5 requiring an ultrahigh vacuum of the lens barrel 3 is mounted on the scanning electron microscope 4. The ion pump 6 is attached. The ion pump 6 includes a pair of cathodes 6
a, an anode cell 6b, and a pair of magnets 6c. A casing 6d for accommodating the cathode 6a and the anode cell 6b and the magnet 6c are attached to a supporting member 7 with screws 8a to 8d. Further, the ion pump 6 attached to the support member 7 and integrally configured has the support member 10 attached to the support column 9.
It is supported by. The support column 9 is fixed to the base plate with screws 11a and 11b, the support member 10 is attached to the support column 9 with screws 12a and 12b, and the support member 7 is attached to the support member 10 with screws 13a and 13b.

As described above, in the conventional scanning electron microscope equipped with the ion pump, all the parts constituting the ion pump are integrally attached to the lens barrel, and the supporting member attached to the support column is used as an auxiliary member. By supporting the ion pump, the load of the ion pump is not applied to the main body of the scanning electron microscope.

[0004]

However, even with such a configuration, since the ion pump is attached to the electron gun chamber located at the uppermost stage of the lens barrel, the connection between the lens barrel and the sample chamber is not achieved. Is applied with a large moment load, and when the ion pump shakes due to vibration, the lens barrel shakes greatly and the irradiation position of the electron beam on the sample deviates from the predetermined position.
A good image cannot be obtained.

Further, in the apparatus shown in FIG. 1, since the lens barrel and the column are connected via the ion pump, when the column is shaken by external vibration, the vibration is directly transmitted to the lens barrel. However, a good image cannot be obtained.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a charged particle beam apparatus provided with an ion pump in which the load of the ion pump is not applied to the lens barrel.

[0007]

Means for Solving the Problems A charged particle beam device equipped with an ion pump of the present invention that achieves this object is a charged particle beam device equipped with an ion pump composed of a cathode, an anode cell, and a magnet. The casing containing the cathode and anode cells is configured separately from the magnet, the casing is attached to the casing side of the charged particle beam device including the exhaust chamber, and the magnet is provided separately from the casing. It is characterized by being attached to.

[0008]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows an example of a charged particle beam device equipped with the ion pump of the present invention. In the figure, the same reference numerals as those in FIG. 1 indicate the same constituent elements.

In FIG. 2, a casing 6d accommodating the cathode 6a and the anode cell 6b and a magnet 6c are constructed separately, and the casing 6d is attached to the outer wall portion of the electron gun chamber 5. On the other hand, the magnet 6c is attached to the support member 14 with screws 8a and 8d, and the support member 14 is attached to the support member 10 with screws 13a and 13b.
Attached by the heavy magnet 6c
Is attached to the column 9 via support members 14 and 10. As described above, in the device shown in FIG. 2, the casing is attached to the electron gun chamber, the magnet is attached to the column, and the casing and the magnet are separated and fixed separately.

In such a structure, since the heavy magnet 6c and the casing 6d are not connected, only the load of the light casing is applied to the lens barrel.
Almost no moment load is applied to the connecting portion between the lens barrel and the sample chamber, and even if the magnet shakes due to vibration, the lens barrel does not shake significantly. Therefore, the electron beam is applied to a predetermined position on the sample to obtain a good quality scanning electron microscope image. Since the vibration isolator is attached to the base plate, the vibration of the support column does not reach the scanning electron microscope main body through the base plate.

Although the embodiment of the present invention has been described above by taking the scanning electron microscope as an example, the present invention is not limited to this, and the present invention is not limited to the charged particles such as an electron microscope and an electron beam probe microanalyzer. It can also be applied to a wire device.

[0013]

According to the present invention, the casing containing the cathode and the anode cell is formed separately from the magnet, and the casing is attached to the casing side of the charged particle beam device including the exhaust chamber, and the magnet is attached to the casing. Since the magnet is attached to the fixing member provided separately from the housing, the heavy magnet load is not applied to the lens barrel, and the lens barrel does not shake even if the fixing member shakes. Therefore, a good image can be obtained in a scanning electron microscope, for example.

[Brief description of the drawings]

FIG. 1 is a view showing a scanning electron microscope equipped with a conventional ion pump.

FIG. 2 is a diagram showing a scanning electron microscope equipped with an ion pump shown as an example of the present invention.

[Explanation of symbols]

1 ... Base plate, 2 ... Sample chamber, 3 ... Lens barrel, 4 ... Scanning electron microscope, 5 ... Electron gun chamber, 6 ... Ion pump, 6a ...
Cathode, 6b ... Anode cell, 6c ... Magnet, 6
d ... Casing, 7, 10, 14 ... Support member, 8a-8
d, 11a, 11b, 12a, 12b, 13a, 13b
… Screws, 9… Supports

Claims (1)

[Claims] 1. A charged particle beam apparatus comprising an ion pump composed of a cathode, an anode cell and a magnet, wherein a casing accommodating the cathode and the anode cell is constructed separately from the magnet, and the casing is evacuated. A charged particle beam device equipped with an ion pump, characterized in that the magnet is attached to a casing side of a charged particle beam device including a chamber, and the magnet is attached to a fixing member provided separately from the casing.