JPS6041736A - Ion source - Google Patents

Abstract

PURPOSE:To enable to produce ions of the solid phase component in a high melting point metal and the like by providing, in the discharging space of a hollow cathode, a container which is composed of a high melting point material with less reaction and has a thin nozzle to supply a material of the ion source positioned in the container bit by bit to the discharging space. CONSTITUTION:A container 8 for a material of an ion source is provided in the neighborhood of a hollow cathode 1. The container 8 for the material of the ion source, is made of a silica glass pipe with less reaction, and its tip is contracted so as to have a thin nozzle 11. The whole of the ion source portion is exhausted in a high vacuum state. Next, the introduction of gas is carried out and when a discharge is started, the container 8 for the material of the ion source is exposed to the plasma, and the material 10 of the ion source is heated and melted and is supplied to the discharging space through the thin nozzle 11. As a result, ions due to the material 10 of the ion source are generated. Once the material 10 of the ion source is supplied to the discharging space, even if the gas for exciting the discharge is cut off, the plasma due to the material 10 of the ion source is stably maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an improvement in an ion source material supply means for an ion source using discharge plasma.

[Background of the invention]

Conventionally, in ion sources that utilize discharge plasma, the ion source material has been supplied to the discharge space in the form of a gas. Therefore, it has been considered difficult to extract ions with high melting points and the like, which are difficult to handle in a gaseous state.

A conventional technique related to this problem will be explained using a duoplasmatron ion source as an example.

For example, it is shown in Japanese Unexamined Patent Publication No. 50-50599. FIG. 1 shows a cross-sectional view of the configuration of a duoplasmatron ion source. This ion source applies an axial magnetic field (vertical direction in the figure) to the hollow cup 1, to the intermediate electrode 2, to the anode 3, to the extraction electrode 4, and to the space between the intermediate electrode 2 and the anode 1-3. magnet or magnetic field power supply (
(omitted in the figure). The operating principle is to first evacuate the space created by the cathode 1, intermediate electrode 2, and anode 3 to a high vacuum, then introduce an appropriate amount of gas as an ion source gas related to the ion species to be extracted into the space, and A discharge pressure is applied between the anode 3 and the anode 3 to cause discharge and generate plasma 6.

The ion bee 1z 5 is extracted by applying an extraction electric field between the anode 3 and the extraction electrode 4. A drawback of the duoplasmatron ion source with such a conventional configuration is that the ion species are limited to the power of gas phase components, and it is difficult to generate solid phase component ions.

[Purpose of the invention]

Therefore, an object of the present invention is to provide an ion source such as the above-mentioned duoplasmatron type that can extract ions of solid phase components such as high melting point metals without significantly changing its configuration. It is in.

[Summary of the invention]

In order to achieve the above object, the present invention includes a hollow cathode, an anode provided opposite to the hollow cathode, and an anode provided within the discharge space of the hollow cathode.
The ion source is constructed by comprising a container made of a high melting point material with low reactivity and having pores that can supply the ion source material placed inside the container in minute amounts to the discharge space. It is characterized by

This characteristic configuration of the present invention makes it possible to generate not only gas component ions but also solid phase component ions, and can be realized with a simple configuration, making it possible to provide an ion source that is inexpensive and has a wide range of applications.

In other words, in terms of hardware, in the present invention, the discharge space of a conventional hollow cathode is made of a high melting point material such as quartz glass or alumina porcelain with low reactivity, and the ion source material sealed inside is discharged in minute amounts. An ion source material container is provided having a pore such that it can be supplied to the space. Next, as for the operation, first perform a scum discharge in the same manner as the conventional method,
The container is heated to melt the ion source material therein, and the ion source material is gradually supplied to the discharge space through the pores of the container to ionize metals and other solid phase elements.

Any element, compound, or mixture can be used as the ion source material, but in the case of a compound or mixture, by appropriately selecting the composition and composition ratio, the temperature of the container can be lowered, and it is easy to Ion source material can be supplied to the discharge space through the pores.

[Embodiments of the invention]

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

FIG. 2 shows the basic configuration of a duoplasma one-heron type ion source according to the present invention.

FIG. 2 shows a state in which the present invention is applied to the conventional duo plasma 1 to Ron type ion source shown in FIG. This ion source consists of a conventional cup 1-1, an intermediate electrode 2, and an anode 1<3.
In addition to the extraction electrode 4, the ion source material container 8 is newly installed near the hollow cup. The cathode 1 has a gas 4 contained in the ion source material.
An exhaust lower has been installed to efficiently carry out air conditioning. Further, a support screw 9 for supporting the ion source material container 8 was provided in a row.

The ion source material 10 uses quartz glass with low reactivity, and the tip of the glass vibrator is 0.1 to 0.5 IIIll.
It is drawn to have a pore 11 of φ, thereby controlling the amount of ion source material introduced into the discharge space.

Operation m (The principle is to first evacuate the entire ion source section to a high vacuum as in the conventional case, then conduct the gas conductor and start the discharge in the conventional manner.Ion source material container 8 and ion source material 1
o is exposed to plasma, heated and melted, and pore 1
1 to the discharge space. As a result, ions are generated by the ion source material 1o. Once the ion source material 10 is supplied to the discharge space, the plasma generated by the ion source material 10 is stably maintained even if the discharge excitation gas is cut off. The plasma state can be stably controlled by changing the discharge pressure.

As the ion source material 10, 7. Although various compounds and mixtures can be used - as an example the operating characteristics are shown using Cs CI. Ion source capacity H; (8 is made of quartz glass, and 0.1 nwnφ was used as the pore 11 for supplying the ion source material 10. 001TIΔ, 300 μA at C8, C
11j of 450 μA at I-. Stability is 1~51”7
/ ] O, which is comparable to that of a conventional gas ion source. Also, the life of an ion source depends on the amount of material it has, but I
When CsCl of gr is used and the ion current is 300μ, stable operation is achieved for +t:IOO11,1″.

〔Effect of the invention〕

- As described in detail, the present invention makes it possible to extract in-phase component ions such as those with high melting points in an ion source such as a child core plasmatron without significantly changing its structure. It becomes possible.

[Brief explanation of the drawing]

Figure 1 is a basic configuration diagram of a conventional Duo Plasma 1-Ron type ion source, and Figure 2 is a diagram of the basic configuration of a conventional Duo Plasma 1-
FIG. 2 is a basic configuration diagram of a Ron type ion source. 1. Hollow cathode, 2. Intermediate electrode (!1.3 Anno-1, 4. Extracting electrode, 5-ion beam 11.6
Plasma, 7... 1 exhaust, 8 container, 9 support screw, 10... ion source charge, 11 ・Button hole. 1st figure stone 2Ln

Claims (1)

[Claims] 1. A hollow cathode, an anode provided opposite to the hollow cathode; an ion source comprising: a container having pores capable of supplying minute amounts of ion source material into the discharge space;