JPH09288980A - Cathode supply ion source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a worn cathode to be replaced with a new one by using a small power supply without exposing a device to atmosphere by permitting an ion beam to converge well in the case of the type which utilizes a heat filament. SOLUTION: A supply reel 6 for feeding a new filament and a take-up reel 7 for collecting a worn filament are placed. By rotating the reels, the filament is replaced at certain time intervals, or the degree of wear of the filament 1 in use is detected from filament current and voltage or ion current, and when it reaches a set value, the filament 1 is replaced either manually or automatically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode supply type ion source. More specifically, the present invention relates to a technical field utilizing ions in a vacuum, such as creation of electronic materials, photo-related materials, coating materials, and other various ion processing, and further physical analysis for analyzing the composition and structure of materials. In a cathode-fed ion source.

[0002]

2. Description of the Related Art The cathode of an ion source device of the hot filament type is preferably made of a material having a high thermionic emission rate. In order to obtain many ions, it is necessary to generate a large amount of thermoelectrons first. Therefore, the material of the filament has conductivity, low sputtering yield, high melting point, and low vapor pressure substance. Is desirable as its physical property, and tungsten has been used conventionally.

However, the conventional ion source has a problem that the filament is rapidly consumed due to the ion sputtering effect, thermal evaporation, and the like. Therefore, in order to withstand long-term use, it is necessary to thicken the wire diameter of tungsten, but if the wire diameter of the filament becomes thick, the converging property of the ion beam emitted from the ion source decreases, and further, Since a large current needs to flow in order to obtain sufficient thermoelectrons in a filament having a large wire diameter, the drawback that a power source with a large current capacity is required is inevitable.

Further, in the conventional ion source device, when the filament is consumed and the performance of ion generation is deteriorated, it is necessary to expose the device to the atmosphere and replace it with a new cathode. It takes a lot of time and labor to perform the necessary gas discharge operation and the adjustment work of the ion beam after replacement, and further, the ultimate pressure and vacuum quality inside the equipment deteriorate due to exposure of the equipment to the atmosphere, etc. There was also a problem.

The present invention has been made in view of the above circumstances, and in a filament type ion source device for generating various ions such as gas ions and metal ions in a vacuum, the filament diameter of the filament type is the same as the conventional one. It is possible to replace the exhausted cathode without making the beam thicker, to improve the convergence of the ion beam, to use a power source with a relatively small current capacity, and without exposing the device to the atmosphere.
It is intended to provide a new ion source device.

[0006]

In order to solve the above-mentioned problems, the present invention is a hot filament type ion source device, in which a filament is introduced into an ionization chamber through an introduction part and a recovery part provided in the ionization chamber. Equipped with a means for moving and supplying and a means for collecting the consumed filament from the ionization chamber, and manually or automatically introducing a new filament into the ionization chamber, and continuously exchanging the consumed filament without exposing to the atmosphere. A cathode supply type ion source device (claim 1) is provided.

Further, the present invention is the above-mentioned device, wherein a filament supply reel for rewinding and supplying a wound filament for moving and supplying a long filament, and a consumable filament in the ionization chamber. A filament take-up reel that collects and rotates the filament take-up reel and the filament supply reel that can be rotated manually or automatically introduces a new filament into the ionization chamber, and continuously consumes the consumed filament without exposing it to the atmosphere. Provided is a cathode-fed ion source device (claim 2), which is exchanged.

Furthermore, the present invention provides a cathode-fed ion source device (claim 3) in which the filament is a single wire or a twisted wire of a plurality of fine wires, and the filament is replaced at regular time intervals or is in use. Also provided is an aspect such as a cathode supply type ion source device (Claim 4) which detects the consumption of the filament by detecting the filament current / voltage, the ion current, etc., and when any one of them reaches a certain set value, it is replaced manually or automatically. To do.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, with the above construction, it is possible to continuously replace a consumed filament with a new filament by means of filament supply means and recovery means arranged in the ion source device. There is. Therefore, for example, when a supply reel is used as the supply means and a take-up reel is used as the recovery means, a filament having a small diameter and flexibility can be used, which improves ion beam convergence. Allows the use of smaller power supplies. In the case of the filament winding method, a filament wire having a diameter of about 0.01 to 0.5 mm can also be used, and the focusing property of the ion beam is proportional to the wire diameter of the filament. The ion beam converging property is much improved as compared with a filament of about 2 mm. Further, it is not necessary to expose the device to the atmosphere to replace it with a new cathode, and accordingly, the gas discharge operation and the adjustment work of the ion beam after replacement, which are required every time the filament is replaced, are also unnecessary. Further, in the conventional ion source, it is possible to prevent deterioration of ultimate pressure and vacuum quality caused by exposing the apparatus to the atmosphere when replacing the filament. Since the consumed filaments can be continuously replaced, the ion source can be operated continuously for a long time.

The supply reel and the take-up reel may be rotated manually or automatically, and the size of these reels, the filament, the winding amount, and the length are appropriately determined. Hereinafter, the cathode supply type ion source device will be described in more detail with reference to Examples.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 of the accompanying drawings is a cross-sectional view illustrating a cathode supply type ion source device of the present invention. FIG. 2 exemplifies the overall configuration of an ion beam irradiation device in which an ion source device is attached to a vacuum container. Although a so-called Freeman type ion source device is shown in this example, the cathode supply type ion source device of the present invention is not limited to this type.

In the illustrated apparatus of FIG. 1, a working gas is introduced into the ionization chamber B from the gas inlet A, and the filament (1) is energized through the upper filament electrode (2) and the lower filament electrode (3). As a result, plasma is generated between the anode (4) and the extraction electrode (1
Ions are extracted by applying a bias to 4). The voltage is applied to the anode (4) through the anode electrode (5).

As the filament (1), a single wire or a stranded wire having a smaller diameter than that of a conventional filament can be used. Then, as illustrated in FIG. 1, a filament (1) of several tens of centimeters to several meters is wound around a supply reel (6) as necessary, and the filament (1) is introduced from the supply reel (6) into the ionization chamber. It is supplied, penetrates the ionization chamber, and is collected by the take-up reel (7).

By energizing the filament (1) through the upper filament electrode (2) and the lower filament electrode (3), for example, from the supply side auxiliary roller (10) to the winding side auxiliary roller (11), 50 mm
Filaments (1) are heated. The filament (1) is guided to the ionization chamber through an upper insulator (12) and a lower insulator (13) arranged in the anode (4) in order to prevent contact with the anode (4).

Usually, in order to extract a constant ionic current, the current or voltage applied to the filament (1) is controlled and held at a set value. The life of the filament (1) can be known from changes in the filament current / voltage and the ionic current. For example, in the case of constant current control, when the voltage reaches 1.3 times the initial value, the take-up reel (7) is rotated manually or automatically for about 50 m.
m winding and supplying new filament (1).

Supply reel (6) and take-up reel (7)
Are electrically insulated from each other, and the vacuum is maintained by the supply side rotary drive (8) and the winding side rotary drive (9) which are attached to the vacuum flange (16) as required. Is rotated. These vacuum flanges (1
The ion source attached to 6) is covered with a protective cover (15) for preventing discharge with other housings.

Of course, the present invention is not limited to the above examples. The present invention includes various mechanisms and modes for linearly supplying the filament into the ionization chamber B and collecting the consumed filament without using the reel. The details can vary.

[0018]

As described above in detail, according to the present invention, since a long filament having a smaller diameter and flexibility can be continuously supplied and collected, the ion beam can be converged favorably and the power source can be downsized. Not only the time and labor for exchanging the cathode can be reduced, but also the degree of vacuum and the quality of the vacuum can be maintained in a good state for a long time, so that it is possible to create a high-purity substance and perform highly accurate analysis.

The apparatus of the present invention can bring a great effect to the technical field utilizing ions.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cathode supply type ion source of the present invention.

FIG. 2 is a cross-sectional view illustrating an ion beam irradiation device equipped with the device of FIG.

[Explanation of symbols]

 1 Filament 2 Upper filament electrode 3 Lower filament electrode 4 Anode 5 Anode electrode 6 Supply reel 7 Take-up reel 8 Supply reel rotation drive machine 9 Take-up reel rotation drive machine 10 Supply side auxiliary reel 11 Winding side auxiliary reel 12 Supply side insulation Insulator 13 Winding-side insulator 14 Extraction electrode 15 Protective cover 16 Vacuum flange A Gas inlet B Ionization chamber

Claims (4)

[Claims] 1. A hot-filament type ion source device, comprising means for moving and supplying filaments into the ionization chamber through an introduction part and a collection part provided in the ionization chamber, and collecting the consumed filaments from the ionization chamber. Means for introducing a new filament into the ionization chamber manually or automatically, and continuously replacing the exhausted filament without exposing it to the atmosphere. 2. The apparatus according to claim 1, wherein a filament supply reel that rewinds and supplies a filament wound in order to move and supply a long filament and a spent filament are collected from the ionization chamber. With a filament take-up reel that can be rotated manually or automatically, a new filament is introduced into the ionization chamber by the rotation of the filament take-up reel and the filament supply reel, and the exhausted filament is continuously replaced without being exposed to the atmosphere. A cathode supply type ion source device characterized in that 3. A cathode supply type ion source device according to claim 1, wherein the filament comprises a single wire or a twisted wire of a plurality of thin wires. 4. The filament is replaced at regular time intervals, or the degree of wear of the filament in use is detected manually by detecting filament current / voltage, ion current, etc., and when the set value is reached, it is replaced manually or automatically. 1. A cathode supply type ion source device according to any one of 1 to 3.