JPH0612995A - Ion source electrode - Google Patents

Abstract

PURPOSE:To provide an ion beam of large current density with low energy by providing an electrode structure wherein a distance between a plurality of sheets of electrodes can be decreased, in an ion source electrode formed of a plurality of sheets of the electrodes piled together. CONSTITUTION:Many fine metal wires 6 of 1mm or less diameter are parallelly arranged closely in a transverse direction and secured to a supporting frame 8, to form an electrode having a slit hole of space in the same degree to a diameter of the metal wire 6. A plurality of sheets of the electrode thus formed are piled together by providing a space in the same degree to the space of the slit hole, to obtain an ion source electrode. For always applying tensile force to the metal wire 6, a spring mechansim 7 is provided in at least one end part of the metal wire 6. In order to prevent the fellow adjacent supporting frame 8 of the electrode and part of the spring mechansim 7 from interfering with each other, the one electrode metal wire 6 of a plurality of the adjacent electrodes is formed in only a straight line, and both end parts of the other electrode metal wire 6 are bent with curvature of not interfering in the point end part of a support 9.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an ion source electrode. More specifically, the present invention relates to the structure of an ion source electrode for generating a low energy ion beam at a high current density.

[0002]

2. Description of the Related Art Conventionally, an ion source has been an important elemental technology in various fields such as creation of various new materials, manufacturing of electronic devices, and analysis. Normally, in this ion source, as an ion source electrode for extracting and accelerating a large current ion beam, a thickness of 1 mm to several mm
A metal plate having a structure in which a large number of round holes each having a diameter of several mm to several tens mm or a plurality of slit holes each having a width of several mm are opened and stacked with a gap is often used. In addition, as an ion source electrode that does not use a metal plate, there is an example of an electrode that forms a slit hole by arranging a number of linear metal rods with one end fixed, but also in this case, the width of the metal rod and the width of the slit. Was a few mm. 1 (a) and 1 (b) are a plan view and a sectional view of an ion source electrode using this conventional metal plate, and FIGS. 2 (a) and 2 (b) are plan views of an electrode in which conventional metal rods are arranged. And a cross-sectional view. In FIGS. 1 (a) and 1 (b),
1 is an electrode and 2 is a round hole provided in the electrode 1.
As shown in (b), two electrodes are stacked to form an ion source electrode. In addition, in FIGS. 2A and 2B, 3 is a metal rod, and slit holes 4 are formed between the metal rods 3. Reference numeral 5 is a support frame for the metal rod. Figure 2 (b)
As shown in FIG. 5, the two electrodes are similarly stacked to form the ion source electrode.

On the other hand, according to the Child-Langmuir rule regarding the extraction of ions, the maximum current density J that can be extracted is given by the following equation.

[0004]

[Equation 1]

Here, V is the voltage applied between the electrodes, d is the distance between two overlapping electrodes, M is the mass number of ions, and Z is
Is the number of charges of the ion. That is, the maximum current density J can take a larger value as the distance d between the electrodes becomes smaller. However, in order to maintain good beam optics, the distance d between the electrodes needs to be about the same size as the diameter or width of the hole. Therefore, the distance d between the conventional electrodes is several mm, which is about the same as the size of the hole. It was set to several tens of millimeters. If the voltage V applied between the electrodes was sufficiently large, it was possible to obtain a sufficient current density even in that case.

However, when an ion beam with extremely low energy is required for applications such as surface treatment with an ion beam, the voltage V applied between the electrodes becomes a small value, and a high current is obtained at the conventional distance between the electrodes. No density can be obtained. Therefore, it is necessary to reduce the diameter or width of the holes to reduce the distance between the electrodes, but it is difficult to open many small holes with the electrode using the conventional metal plate as described above, and the mechanical strength The thickness of the electrode is usually 1 due to the limitation of
Since it is more than mm, the distance between the electrodes cannot be reduced to less than 1 mm.

Also, in the case of a conventional electrode having a slit hole using a metal rod, the width of the slit and the thickness of the metal rod are required to be 1 mm to several mm due to the limitation of mechanical strength. Was a few mm. Due to such a limitation, it has hitherto been impossible to obtain an ion beam with low energy and high current density.

The present invention has been made in order to solve the problems as described above, and it is possible to eliminate the drawbacks of the conventional ion source electrodes and reduce the distance between a plurality of superposed electrodes. The purpose of the present invention is to provide a new ion source electrode that can obtain an ion beam with a large current density even with low energy and can efficiently cope with processes such as surface treatment by adopting a different electrode structure. .

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an ion source electrode constructed by stacking a plurality of electrodes at intervals with a diameter of 1 mm or less for each stacked electrode. An electrode in which a plurality of metal wires are densely arranged and a plurality of slit holes having a width similar to the diameter are formed,
Provided is an ion source electrode, which is characterized in that a plurality of them are arranged so as to be overlapped with each other at an interval substantially equal to the width of a slit hole.
With this electrode structure, the diameter of the metal wire can be easily reduced, and it is easy to arrange a large number of metal wires.
It is possible to easily manufacture an electrode having an extremely narrow slit width. Therefore, if a plurality of electrodes having such a structure are closely stacked, the electrode interval can be made extremely small.

Further, when the diameter of the metal wire is extremely small as in the present invention, deformation of the metal wire due to thermal expansion or vibration becomes a problem, but in the present invention, a spring mechanism is provided at one end or both ends of the metal wire. It is provided to prevent deformation by constantly applying tensile force to the metal wire. Further, in order to prevent the support frame of each electrode and the portion of the spring mechanism from interfering with each other when the electrodes are overlapped with each other, in the present invention, the metal wire of one electrode of the adjacent electrodes of the overlapped plurality of electrodes is used. Is composed of only a straight line, and bent portions having a curvature that does not interfere with both ends of the metal wire of the other electrode are provided.

Hereinafter, the present invention will be described in more detail with reference to examples.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 (a) is a plan view of an ion source electrode of the present invention, FIG. 3 (b) is a side view, and FIG. 3 (c) is a metal wire portion forming a slit hole for extracting and accelerating an ion beam. FIG. As shown in FIG. 3 (a), a large number of metal wires 6 having a diameter of 1 mm or less are densely arranged laterally on a support frame 8 to form an electrode having slit-shaped holes having a width approximately equal to the diameter of the metal wires. As shown in FIGS. 3 (b) and 3 (c), the electrodes are superposed at extremely narrow intervals, that is, at intervals of the same order as the diameter of the metal wire. In this way, an ion source electrode having an extremely small electrode interval can be manufactured.

Further, one end of the metal wire 6 is attached to the spring mechanism 7
It is possible to prevent deformation due to thermal expansion or vibration by constantly pulling with. In the spring mechanism 7, as shown in FIG. 3B, the end portion of the support frame 8 has an outer support frame 8b.
And an inner support frame 8a, and an outer support frame 8b is an inner support frame 8a.
Move from a to the outside. The metal wire 6 is fixed to the outer support frame 8b at the end of the electrode and slidable on the inner support frame 8a, and a compression spring is arranged between the outer support frame 8b and the inner support frame 8a. By doing so, the outer support frame to which the metal wire is fixed is pushed outward from the inner support frame by the repulsive force of the compression spring, so that the metal wire is always subjected to a pulling force. Of course, in the example of FIGS. 3A, 3B, and 3C, the spring mechanism 7 is provided at one end of the metal wire 6, but it can of course be provided at both ends of the metal wire.

Further, as shown in FIG. 3B, in the above example, when a plurality of electrodes are superposed, the support frame 8 of the electrodes, the spring mechanism 7, etc. do not vertically interfere with each other.
Both ends of the metal wire 6 of the electrode are bent at the tip of the support 9. This is because the diameter of the metal wire used in the present invention is extremely small, so that even if the metal wire has a curvature, a tensile force can be applied to the metal wire by the spring mechanism.

[0015]

As described above, by manufacturing an ion source electrode according to the present invention, it is possible to make the electrode interval of a plurality of superposed electrodes extremely narrow, and even when the voltage applied to the electrodes is low, That is, even if the energy of the ion beam is low, it is possible to obtain an ion beam with a large current density. Therefore, with very low energy,
In addition, it is possible to efficiently perform a surface treatment that requires an ion beam with a large current density.

[Brief description of drawings]

FIG. 1A is a plan view of an ion source electrode using a metal plate, and FIG. 1B is a cross-sectional view of the ion source electrode using a metal plate.

FIG. 2A is a plan view of an ion source electrode using a metal rod, and FIG. 2B is a cross-sectional view of the ion source electrode using a metal rod.

3A is a plan view of the ion source electrode of the present invention, FIG. 3B is a side view of the ion source electrode of the present invention, and FIG. 3C is a side view of the ion source electrode of the present invention. It is a cross-sectional enlarged view of a metal wire portion.

[Explanation of symbols]

 1 Electrode Plate 2 Round Hole 3 Metal Rod 4 Slit Hole 5 Support Frame 6 Metal Wire 7 Spring Mechanism 8 Support Frame 9 Support

Claims (3)

[Claims] 1. An electrode in which a plurality of metal wires having a diameter of 1 mm or less are densely arranged and a plurality of slit holes having a width approximately equal to the diameter are formed at a distance approximately the same as the width of the slit holes. An ion source electrode characterized by being provided. 2. The ion source electrode according to claim 1, wherein a spring mechanism for constantly applying a tensile force to the metal wire is provided on at least one end of the metal wire. 3. The metal wire of one electrode adjacent to a plurality of electrodes is composed of only a straight line, and the metal wire of the other electrode is composed of a metal wire having bent portions at both ends. Item 1 or 2 of the ion source electrode.