JPH01115041A - Movement introduction mechanism of charged particle beam device - Google Patents

Abstract

PURPOSE:To obtain stable operation in a vacuum chamber high in its cleanness without doing a magnetic effect on charged particle beams by using an arm to link a driving part with a sample holder and installing a partition wall in the midst of the arm to separate the magnetic atmosphere from the vacuum state. CONSTITUTION:A partition wall is used to divide a low vacuum chamber 3, where a movement mechanism 2 is housed, from a high vacuum mechanism 2, where a charged particle beam channel 1 is housed. A sample holder 7 and the movement mechanism 2 are housed inside the high vacuum chamber 5 and the low vacuum chamber 3 respectively. An arm 15 is used to link the movement mechanism 2 with the sample holder 7 through the partition wall 4. The partition wall 4 is formed in so double structure that it is provided with a fixed wall 19, which has an opening part not to disturb movement of the arm 15, and a plate 20 which has the same hole in its cross-sectional shape as the arm 15 and tunes with the movement of the arm 15 and is capable of closing the opening part of the fixed wall 19 upon the moving of the arm 15, so that no disturbance occurs in a magnetic circuit 32. The high vacuum chamber 5 can be made vacuum highly in its purity.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to processing, measurement, analysis, or inspection equipment that utilizes charged particle beams, and is particularly suitable for preventing the influence of magnetism and preventing sample contamination. This invention relates to a motion introduction mechanism for a charged particle beam device.

[Conventional technology]

Conventional equipment divides a vacuum container into several vacuum-independent chambers as described in Japanese Patent Application Laid-Open No. 59-29434.
A moving table consisting of axis, Y-axis, and Z-axis stages and guide sections for each axis is placed in a high vacuum chamber through which the charged particle beam passes, and the gears and screw rows of the moving mechanism are housed in a low vacuum chamber, and the drive source is exposed to the atmosphere. It was a structure built inside.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology includes a moving table that causes the charged particle beam emitted from the charged particle beam source to undergo shape deformation or bending due to magnetism before it reaches the sample. However, it is difficult to construct a precision moving table that requires accuracy of 1 μm or less from non-magnetic parts, and great efforts have been made to reduce the influence of this magnetism on charged particle beams. In addition, precision moving tables must use lubricants to improve the slippage between parts. Therefore, it is difficult to completely eliminate impurities released from the lubricant and the surfaces of the components. In other words, in the conventional method, the charged particle beam is bent by magnetic field fluctuations caused by the movement of magnetic parts used in the moving table, and by impurities released from the lubricant of the mechanism and the surface of the component parts. There was a problem that the degree of vacuum and the quality of the vacuum deteriorated.

The purpose of the present invention is to simultaneously solve the problems of the above-mentioned prior art,
It is an object of the present invention to provide a motion introduction mechanism that effectively uses a highly clean charged particle beam without imparting magnetic fluctuations to the charged particle beam.

[Means for solving problems]

The above object is achieved by connecting the drive unit, which often has magnetism, and the sample holder with an arm, and installing a partition wall between the magnetism and vacuum in the middle of this arm.

The partition wall consists of a fixed wall with an opening that does not interfere with the range of movement of the arm, and a movable wall that moves while constantly contacting the fixed wall and closing the opening according to the movement of the arm.

[Effect]

In the present invention, the partition wall operates while constantly forming a magnetic path. Therefore, the magnetic field from the moving mechanism does not enter the path of the charged particle beam, so the charged particle beam is not affected by adverse effects such as changes in shape or bending. In addition, since the parts inside the charged particle beam passage can be configured in the smallest units, it is possible to extremely suppress impurities emitted from the surfaces of these parts, and the inside of the charged particle beam passage is kept in a clean, high-quality vacuum. It can be done.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

A low vacuum chamber 3 housing a charged particle beam passage 1 and a moving mechanism 2 of the high vacuum chamber is separated from a high vacuum chamber 5 by a partition wall 4 . Inside the high vacuum chamber 5 are a sample holder 7 for fixing a sample 6 used for processing, analysis, inspection, etc., and a control section 9 for the charged particle beam 8. Inside the low vacuum chamber 3 are X-axis, Y-axis, and Z-axes. Axis movement mechanism 2
are each stored separately. A charged particle beam source 10 is attached to the wall of the high vacuum chamber 5, and the interior thereof is also in a high vacuum.

Also, on the outer wall of the low vacuum chamber 3, an X axis, a Y axis (not shown),
A motor, 11.12, for driving the Z-axis is installed and vacuum sealed with a magnetic fluid seal 13.14.

The moving mechanism 2 and the sample holder 7 are connected by an arm 15 through the partition wall 4.

The vacuum evacuation system is a high vacuum evacuation pump 16. It consists of a low vacuum pump 17 and a valve 18. The high vacuum chamber is simultaneously evacuated to a low vacuum by the low vacuum pump 17 through the valve 18 to the low vacuum chamber 3 housing the moving mechanism 2, and then raised to about 10-10''-BPa by the high vacuum pump 16. The low vacuum chamber 3 is evacuated to about 10-1 to 10'' Pa by the low vacuum pump 17.

The partition wall 4 includes a fixed wall 19 having an opening that does not hinder the movement of the arm 15 when it moves in x, y, and z, and a fixed wall 19 that has a hole that has the same cross-sectional shape as the arm 15 and synchronizes with the movement of the arm 15. It has a double structure of a plate 20 having a size that can close the opening of the fixed wall 19 when the fixed wall 19 moves. This structure prevents disturbances in the magnetic circuit 32. The material of this plate 2o is 78% Ni-Fe, which is the same material as the wall of the container. In addition, sliding materials 21 and 22 having a low coefficient of friction, such as fluororesin, are inserted into the plate 20 at the portion in contact with the fixed wall 19 and between the hole and the arm 15. Furthermore, this plate 20 is always in contact with the fixed wall 19 having an opening by means of a support 23 and a spring 24 arranged and placed in the high vacuum chamber 5.

The sample 6 is driven in the X-ray direction by a motor 11 attached to the outer wall of the low vacuum chamber 3. The rotational movement of the motor 11 is introduced from the atmosphere into the low vacuum chamber 3 under vacuum sealing with a magnetic fluid seal 13. , is converted into linear motion by the ball screw 25. Then, the arm 15 is moved straight through the low vacuum chamber partition wall 4 that separates the sample holder 3 from the high vacuum chamber 5, and the sample holder 7 connected to this arm 15 is driven.

The driving in the Y-axis and Z-axis directions is the same as the driving in the X@force direction, so a description thereof will be omitted.

According to this embodiment, the low vacuum chamber 3 and the high vacuum chamber 5 were separated by the partition wall 4, so that the high vacuum chamber 5 could be made into a highly clean vacuum. Also.

By using sliding materials 21 and 22 with a low coefficient of friction in the sliding parts of the partition wall 4, the sliding resistance of the arms 15 can be reduced. As a result, it became possible to use a small-capacity motor as the drive source. Furthermore, since the low vacuum/empty chamber 3 and the high vacuum chamber 5 are simultaneously evacuated by the valve 18, atmospheric pressure is not directly applied to the partition wall 4.

Therefore, there is an effect that the partition wall 4 is not limited in size or thickness.

Although this embodiment has been explained using an example in which the sample is moved, the effect remains the same even if the sample is fixed and the control system for controlling the charged particle beam is moved.

Furthermore, the partition wall separating the low vacuum chamber and the high vacuum chamber can be placed in opposite positions by replacing the fixed wall and the movable plate.

Furthermore, there are other methods that can be considered to ensure that the charged particle beam does not have magnetic effects and can operate stably in a highly clean, high-vacuum chamber, as shown in Figures 3 and 4. .

As shown in FIG. 3, one of the partition walls separating the low vacuum chamber 3 and the high vacuum chamber 5 is a fixed wall 19 with an opening that does not interfere with the movement of the arm 26 that is moved by the moving mechanism, and the other wall is a fixed wall 19 with a sample holder. A bellows 27 is fixed to the arm 26 and contracts in parallel with the arm 26 that connects the moving mechanism 2 to the bellows 27.

When the arm 26 is moved by the moving mechanism 2, the bellows 27 fixed to the arm 26 is not compressed at all times, so the other end slides on the surface of the fixed wall 19. At this time, fix the arm 26 so that its movement is smooth! A sliding member 28 was inserted between t19 and bellows 27.

Further, as shown in FIG. 4, the opening of the fixing g119 fixes one end of the bellows 27, and the other end fixes a plate 29 having a hole. The cross sections of this hole and the arm 15 have the same shape. Further, the plate 29 is connected to the fixed wall 19 by a tension spring 30. moreover.

A sliding member 31 was inserted between the arm 15 and the plate 29.

The arm 15 regulated by the moving mechanism 2 changes the position of the plate 29 by the movement of the moving mechanism 2.

At this time, the low vacuum chamber 3 and the high vacuum chamber 5 are always separated by a bellows 27 fixed to a plate 29 that moves following the movement of the arm 15.

〔Effect of the invention〕

According to the present invention, when a charged particle beam moves a sample or a charged particle beam control system, it is possible to separate the magnetic moving mechanism with a partition wall, and there is no adverse effect such as shape change or bending due to magnetism. I don't accept it. Further, the partition wall vacuum-separates the chamber in which the charged electromagnetic radiation and the sample enter and the chamber in which the moving mechanism is housed. Therefore, the sliding parts of the moving mechanism can be easily lubricated, making it possible to extend the life of the mechanical parts. Furthermore, by constructing the chamber in which the sample enters with parts that emit a small amount of gas, a highly clean vacuum is created, which allows the charged particle beam to operate stably.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a motion introducing mechanism according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line A-A of the arm, and FIGS. 3 and 4 are partition walls according to other embodiments of the present invention. FIG. 3 is a side sectional view of the portion. 1... Charged particle beam path, 2... Movement mechanism, 3...
Low vacuum chamber, 4... Partition wall, 5... High vacuum chamber, 6.
...sample, 7...sample holder, 8...charged particle beam,
10...Charged particle beam source, 11.12...Motor, 1
3,14...Magnetic fluid seal, 15.26...Arm,
16...High vacuum pump, 17...Low vacuum pump, 1
8...Valve, 19...Fixed wall, 20.29...
Plate, 21, 22, 28. 31...Sliding material, 24...
Spring, 25... Ball screw, 27... Bellows, 9
...Control unit, 23...Support, 30...Tension first
Figure c73 P1 [Tsuta Senmori Figure 2

Claims (1)

[Claims] 1. A charged particle beam apparatus comprising a charged particle beam source, a control system for controlling the charged particles, and a sample stage for holding a sample, and for moving the control system or the sample stage. A charged particle beam device characterized in that a double wall is provided between the charged particle beams that does not impede the movement of the charged particle beams and that does not create a space during movement, and the charged particle beams are not affected by magnetism. movement induction mechanism. 2. The charged particle beam passageway and the chambers housing the movement mechanism are connected by minute gaps, and the charged particle beam passageway is maintained at a high vacuum by utilizing the pressure difference when each chamber is evacuated. A motion introduction mechanism for a charged particle beam device according to claim 1.