JPH0538050Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention deflects the electron flow heat released from the filament using a magnetic field, guides it to the crucible, evaporates the evaporation source housed in the crucible, and radiates it. The present invention relates to an evaporation source device, and particularly relates to an evaporation source device suitable for application to a small evaporation source device with a filament output of 10 kW or less.

[Prior art] Among electron impact magnetic field deflection type evaporation sources used as evaporation sources in vacuum evaporation equipment and molecular beam epitaxy equipment, the volume of the crucible is relatively small, and therefore the amount of thermionic electrons emitted from the filament is also small. Conventionally, the device had a structure as shown in FIGS. 3 and 4. That is, a filament 2 for emitting thermionic electrons and an anode 3 for accelerating the electron flow emitted from the filament 2 are provided on the side of the crucible 1 that houses the evaporation source, and further, the crucible 1 is sandwiched from both sides. Yokes 5, 5 of the introduction magnet 4 are arranged to form a deflecting magnetic field for guiding the electron flow into the crucible 1.

Among these conventional evaporation source devices, small ones have a small crucible volume and a narrow opening area, so the electron flow is not scanned, and even if it is scanned, the magnetic field generated by the introduction magnet 4 is varied to change the irradiation path of the electron flow slightly.

[Problems to be Solved by the Invention] However, even in such a small-sized evaporation source device, it is strongly desired to efficiently evaporate the evaporation source without wasting it using an electron flow scanning means.

However, in a small evaporation source device, the space around the filament 2 where the electron flow is generated is limited, and it is difficult to arrange an electromagnet for forming a scanning magnetic field. For this reason, for convenience, an electromagnet is used as the introduction magnet 4 to form a fluctuating magnetic field to scan the electron flow, but in this case, a large fluctuation in the magnetic field is required. and unless a fairly large electromagnet is used,
Accurate and extensive scanning of the electron flow cannot be expected.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide an electron impact magnetic field deflection type evaporation source device that can accurately and widely scan an electron flow using a small electromagnet.

[Means for Solving the Problem] That is, the gist of the means adopted in the present invention to achieve the above object is as follows: a crucible 1 that houses an evaporation source a; a filament 2 that emits electrons as heat;
an anode 3 for accelerating the electrons emitted from the filament 2; a scanning magnet 8 for forming a fluctuating magnetic field on the electron radiation path; and an introduction magnet 8 for forming a deflecting magnetic field for introducing the electron flow into the crucible 1. In the electron impact magnetic field deflection type evaporation source device comprising a magnet 4, the scanning magnet 8 has an extraction yoke 9 drawn out from it, and a magnetic pole 9a formed at the tip thereof.
9a is an electron impact magnetic field deflection type evaporation source device characterized in that the filament 2 is placed at opposite poles on both sides.

[Function] In the evaporation source device according to the present invention, the magnetic poles 9a, 9a of the extraction yokes 9, 9 of the scanning magnets 8, 8 are arranged so as to sandwich the filament 2 that generates an electron flow.
Since these are opposite poles, it is possible to deflect and scan the low-energy electron flow immediately after being generated from the filament 2 by the magnetic field generated between the magnetic poles 9a, 9a. For this reason, it becomes possible to perform wide and accurate scanning using the small scanning magnets 8, 8.

Moreover, even if the space around the filament 2 is limited, it is only necessary to arrange the tips of the drawing yokes 9, 9 on both sides of the filament 2, so the scanning magnets 8, 8
It is possible to install the evaporation source away from the surroundings of the filament 2, and even a small evaporation source device can be easily laid out.

[Example] Next, regarding an example of the present invention, FIGS.
This will be explained in detail with reference to the drawings.

The crucible 1 is formed of a chemically and thermally stable ceramic such as silicon nitride into a cup shape with an open top, and yokes 5, 5 of introducing magnets 4, 4 are arranged on both sides of the cup. These introduction magnets 4,
4. The bases of the yokes 5, 5 and the crucible 1 are surrounded by a shield case 10 and are magnetically shielded.

A filament fixing unit 11 is arranged in front of the shield case 10, and the crucible 1
A filament 2 that generates an electron flow is arranged on the side of the filament unit 1, and both ends thereof are connected to the filament unit 1.
It is fixed at 1. An anode 3 is placed directly above the filament 2 to accelerate thermoelectrons generated from the filament 2.

On the other hand, a pair of scanning magnets 8, 8 magnetically shielded by shield cases 12, 12 are arranged on both sides of the shield case 10. The scanning magnets 8, 8 have rod-shaped magnetic pull-out yokes 9, 9 drawn out from a yoke body (not shown) provided with windings.
The tips of the filament 2 are guided to both sides of the filament 2, and magnetic poles 9a and 9b formed at the tips oppose the filament 2 on both sides.

As already mentioned, in the above-mentioned evaporation source device, when the filament 2 is heated, thermoelectrons are emitted from the filament 2. The generated electron current is accelerated by the accelerating voltage applied to the anode 3, and is deflected by the magnetic field formed between the yokes 5, 5 by the introducing magnet 4, and flows from the opening of the crucible 1. is introduced into the evaporation source to evaporate the evaporation source. At this time, the magnetic poles 9a, 9 of the yokes 9, 9 are controlled by the scanning magnets 8, 8.
By varying the magnetic field generated between a,
The electron stream can be scanned. An example of the irradiation path of the electron flow emitted from the filament 2 is shown below.
It is indicated by a broken line in FIG.

[Effects of the invention] As explained above, according to the invention, it is possible to easily lay out the scanning magnets 8, 8 even in a small evaporation source device where the space around the crucible 1 is limited, Furthermore, an effect can be obtained in that it is possible to provide an evaporation source device that can scan the electron flow with great accuracy using the small-sized scanning magnets 8, 8.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an evaporation source showing an embodiment of the present invention, FIG. 2 is a front view of the evaporation source, FIG. 3 is a perspective view of a conventional evaporation source, and FIG. It is a front view of the same conventional example. 1... Crucible, 2... Filament, 3... Anode, 4... Introducing magnet, 5... Yoke of introducing magnet, 8... Scanning magnet, 9... Yoke of scanning magnet, 9a, 9a ...The magnetic pole of the scanning magnet.

Claims (1)

[Scope of utility model registration request] A crucible 1 that houses an evaporation source a, a filament 2 that emits electrons as heat, an anode 3 that accelerates the electrons emitted from the filament 2, and a scanning magnet 8 that forms a fluctuating magnetic field on the emission path of the electrons. , an electron impact magnetic field deflection type evaporation source device comprising an introduction magnet 4 that forms a deflection magnetic field for introducing an electron flow into the crucible 1, wherein the scanning magnet 8 has an extraction yoke 9 drawn out from it; An electron impact magnetic field deflection type evaporation source device characterized in that magnetic poles 9a, 9a formed at the tips thereof are opposite poles on both sides of the filament 2.