JPS636847Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a slit variable device used in energy analyzers and the like.

In an electron microscope, energy analysis of an electron beam transmitted through a sample is often performed. FIG. 1 shows an outline of such energy analysis, in which a thin film sample 1 is irradiated with a narrowly focused electron beam 2, and the transmitted electron beam 3 is guided to an analyzer 4 made of this electrostatic electrode. The electron beam 3 is 3a, 3b, 3c along the y direction of the xy plane perpendicular to the emission direction Z of
It is separated as follows. The distribution of the electron beam intensity in the y direction becomes a spectrum as shown in FIG. 2, but in order to obtain this spectrum, a slit device 5 parallel to the x direction of the xy plane and an electron detector 6 are installed in the subsequent stage. The analyzer voltage E applied to the energy analyzer 4 may be swept, and the output of the detector 6 with respect to the sweep voltage E may be recorded and displayed. At this time, in order to obtain a fine spectrum, the slit interval 5a of the slit device 5 must be made as small as possible. On the other hand, paying attention to the spectrum peak P in FIG. 2, select a slit device 5 that has a relatively large slit width corresponding to the energy width ΔE of this peak waveform, and set the applied voltage of the energy analyzer 4 to _E1. The sample 1 is scanned by the electron beam 2 while the electron beam corresponding to the spectrum P is set to pass through the slit device 5, and the output of the detector 6 is sent to a CRT (not shown) that is synchronized with the scanning. If supplied, the distribution of the material structure that produces the spectrum P within the sample can be observed.

As mentioned above, there are two ways to use an energy analyzer in an electron microscope, and the slit device has two or three slits of different widths prepared in advance depending on the method of use, and they are replaced every time a measurement is made. I was using it. However, when selecting and using a slit with a fixed width, it is impossible to obtain an arbitrary slit width, and it is of course impossible to slightly increase or decrease the slit width to cancel out slight changes in measurement conditions.

The purpose of the present invention is to solve these problems and provide a variable slit device that can perform highly accurate fine adjustment over the entire slit width and coarse adjustment for large slit widths. Z
two slit plates provided in the xy plane perpendicular to the slit plate, two slit holders that regulate the position of the slit in the y direction while keeping the slit side of each slit plate always parallel to the x direction; In a device comprising a moving axis for varying the distance S in the y direction between the slit sides by contacting the holder and moving in the x direction, the amount of movement Δ of the first moving axis is
Amount of movement of each slit side in the Y direction with respect to x △
y ₁ and the amount of movement Δy ₂ of each slit side in the Y direction relative to the amount of movement Δx of the second movement axis are different.

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 3 is a sectional view showing an embodiment of the present invention. In the figure, 10 is a lens barrel of, for example, an electron microscope, and a slit holder 11 passes through the lens barrel 10 in an airtight manner. This holder 11 may be fixed to the lens barrel 10, but it may also be configured to be movable in a plane perpendicular to the electron beam axis Z using a drive mechanism not shown. Inside the lens barrel of the holder 11 are plate springs 12a ₁ , 12a _{2 .}
12b ₁ and 12b ₂ are fixed at one end, and holders 13a and 13b are fixed at the other end of each pair of leaf springs. A slit plate 14a is fixed to the holder 13a, and a slit plate 14b is fixed to the holder 13b, and a minute slit S is formed by the gap between the slit sides of both slit plates.

Note that FIG. 4 is a schematic view of the slit plate viewed from the x-axis direction. Reference numeral 15 denotes a first moving shaft that is movably arranged in an airtight manner within the holder 11, and as shown in detail in FIG. There is. Reference numeral 18 denotes a second moving shaft that is movably arranged in an airtight manner within the holder 11, and the tip portion 18a in the vacuum has a steep slope B.
A taper or slope is formed, and either of the slopes is in contact with the ends of the holders 13a, 13b. The positional relationship between the first moving shaft 15 and the second moving shaft 18 is shown in more detail in FIG. A flange 15b and a flange 18b are formed at the other ends of the first moving shaft 15 and the second moving shaft 18, and a coil spring 16 and a flange 18b are formed between the holder 11 and the flange 15b and 18b. A coil spring 19 is inserted to constantly push the first moving shaft 15 and the second moving shaft 18 toward the outside of the lens barrel. 17 is a first control rod for moving the first moving shaft 15;
Reference numeral 20 denotes a second control rod for moving the second moving shaft 18, and the tips of the control rods 17 and 20 are connected to the flanges 1, respectively.
5b, comes into contact with the end surface of the flange 18b, and the control rod 1
7 and 20 are configured to be movable by a drive device not shown.

In the above configuration, when the control rod 17 or 20 is moved in the M direction by a drive device not shown, the moving shaft 15 or 18 in contact therewith is moved in the axial direction. As a result, the tip portion 15a or 18a pushes the holders 13a, 13b open against the leaf springs 12a ₁ , 12a ₂ , 12b ₁ , 12b ₂ and the width of the slit S becomes wider. When the control rod 17 or 20 is moved in the N direction, the moving shaft 15 or 18 is pushed back to the right (N direction) by the coil spring 16 or 19, and the gap between the holders 13a and 13b becomes narrower, so that the slit S The width becomes narrower. Figure 7 shows the first
Holders 13a, 13 when the moving shaft 15 moves
In this embodiment, the tip 15a is formed with an inclination A.
When the moving shaft 15 is moved, the blocks 13a and 13b in contact with the slope A are pushed open and the slit width S changes. Further, FIG. 8 shows the state of contact with the holders 13a and 13b when the second moving shaft 18 for rough adjustment moves, and the slit width S changes depending on the inclination B.

FIG. 9 is a graph showing the change in the slit width due to the inclination A or B when the first moving axis 15 or the second moving axis 18 of this embodiment is moved. Now, for a constant movement amount Δx of the first moving axis 15, the holders 13a and 13b move by Δy ₁ /2, and therefore the slit width S also changes by ΔS ₁ =2Δy ₁ /2. On the other hand, when the second moving axis 18 moves by a constant amount Δx, the holders 13a and 13b move by Δy ₂ /2, and therefore the slit width S also becomes ΔS ₂ =2Δy ₂ / Only 2 changes. By the way, as shown in FIG.
As A°, the steep inclination B may be set to B° that satisfies, for example, ΔS ₂ =2ΔS ₁ with respect to the central axis of the second moving shaft 18. That is, the moving axes 15 and 1
Assuming that the movement accuracy and movement speed of 8 are constant,
The slope A allows fine adjustment with high accuracy over the entire area of the slope A, and the slope B allows for coarse adjustment but at a faster variable speed of the slit. Therefore, if the slit width has a wide variable range, for example, if you want to change it from 200 μm to 20 μm, you can set it from 200 μm to 50 μm in a short time using the coarse adjustment function (second movement axis 18), and then change it to 50 μm.
Fine adjustment function (first moving axis 15) from to 20μm
By using this, the slit width can be varied with high precision. In addition, if the two moving axes are used as a moving axis for fine adjustment and a moving axis for coarse adjustment in this way, coarse adjustment can be performed while the fine adjustment moving axis remains fixed at a certain slit width. Therefore, it is possible to immediately return to the previous fixed slit width with good reproducibility after using the slit by rough adjustment.

Note that the present invention is not limited to the device of the above embodiment, and in this embodiment, the first moving axis and the second moving axis are provided on the left and right in consideration of moving from the same direction. The first movement axis and the second movement axis may be opposed to each other, and the inclination of the tip of each movement axis may be determined depending on the purpose of analysis.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an energy analyzer, Fig. 2 is a diagram showing the relationship between electron beam intensity and energy, Fig. 3 is a cross-sectional view showing an embodiment of the present invention, and Fig. 4 is a schematic cross-sectional diagram of a slit plate. , FIG. 5 is an enlarged view of the tip of each moving axis, FIG. 6 is a layout diagram of each moving axis, FIG. 7 is a diagram showing the state when the first moving axis moves, and FIG. 8 is an enlarged view of the second moving axis. FIG. 9 is a diagram showing the state when the moving axes are moved. FIG. 9 is a diagram showing the change in the slit width when each moving axis is moved. DESCRIPTION OF SYMBOLS 1... Sample, 2... Electron beam, 3... Transmission electron beam, 4... Analyzer, 5... Slit device, 6
...detector, 10 ... lens barrel, 11 ... slit holder, 12a ₁ , 12a ₂ , 12b ₁ , 12b ₂ ... leaf spring, 13a, 13b ... holder, 14a, 14b
...Slit plate, 15...First movement axis, 16...
Coil spring, 17...first control rod, 18...second
Moving axis, 19...Coil spring, 20...Second control rod.

Claims (1)

[Scope of utility model registration request] Two slit plates provided in the xy plane perpendicular to the axis Z, two slit holders that regulate the position of the slit in the y direction while always keeping the slit side of each slit plate parallel to the x direction, First and second moving axes are provided for varying the distance S in the y direction between the slit sides by contacting both the holders and moving in the x direction, and the amount of movement Δ of the first moving axis is provided. A moving amount Δy ₁ of each of the slit sides in the Y direction with respect to x and a moving amount Δy ₂ of each of the slit sides in the Y direction with respect to the moving amount Δx of the second movement axis are configured to be different. Variable slit device.