JPH05339714A - Electron beam evaporation method - Google Patents

Abstract

(57) [Abstract] [Purpose] A method for evaporating a vaporized material by rotating the vaporized material with an electron beam to evaporate the vaporized material uniformly while forming a uniform vapor deposition film by eliminating vaporization unevenness. Is provided. [Structure] An electron gun 2 and a crucible 4 containing a rotatable evaporation material 5 are installed above an evaporation source main body 1. Magnetic poles 6a and 6b are installed so as to sandwich the electron gun and the crucible, and first and second magnetic pole pieces 8a, 8b and 9a are provided at both ends of each magnetic pole.
Fix 9b. Further, the auxiliary magnetic pole pieces 11a and 11b are fixed to the opposing portions of the magnetic poles. The electron beam E from the electron gun 2 is deflected on the evaporation material 5 by the deflection system 10,
It reciprocates around the rotation center O along the X direction. By adding the auxiliary magnetic pole piece in this way, the shape of the electron beam on the evaporation material changes between the rotation center O portion and the outer peripheral portion thereof to change the current density, so that the evaporation material can be uniformly heated. ..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam evaporation method of an evaporation source in a vacuum evaporation apparatus or an ion plating apparatus, and more particularly, an electron beam evaporation method effective when used for evaporating while rotating an evaporation substance. Regarding

[0002]

2. Description of the Related Art As an electron beam evaporation source used in such an apparatus, a structure having a deflection type of, for example, 180 degrees as shown in FIGS. 1 and 2 is widely used. In the figure, 1 is an evaporation source main body, 2 is an electron gun mounted on the upper surface of the main body, and is composed of a filament, a grid and an anode (not shown). A beam passage hole 3 for passing the electron beam E generated from the filament is formed on the upper surface of the electron gun 2. Reference numeral 4 denotes a bottomed cylindrical crucible placed on the upper surface of the main body 1 similarly to this electron gun, and an evaporation substance 5 is loaded inside. The electron gun 2 and the crucible 4 are arranged at appropriate intervals along the X direction. Reference numerals 6a and 6b denote a pair of magnetic poles for deflecting the electron beam E generated from the electron gun 2 to generate a deflection magnetic field B for irradiating the evaporation material 5 on the evaporation material 5, and each magnetic pole holds the electron gun 2 and the crucible 4 between them. They are arranged so as to sandwich each other and face each other along the Y direction. The magnetic poles are fixed to both ends of a yoke 7 having a U-shaped cross section attached to the main body 1. A coil (not shown) for generating magnetic flux is wound around the yoke.

8a, 8b and 9a, 9b are the magnetic poles 6a
And 6b are beam-forming first and second pole pieces fixed respectively, and the first pole pieces 8a and 8b are arranged so that their respective open ends are close to the electron gun 2, whereby the electron gun 2 is provided. It serves to deflect the electron beam E emitted from the beam passage hole 3 toward the crucible 4 while converging it without diverging it. In addition, the second pole piece 9a,
Similarly, 9b is also arranged such that each open end approaches the crucible 4 (evaporation material 5), and serves to focus the shape of the electron beam E with which the evaporation material is irradiated in a spot shape as small as possible. .. Here, the shape of the electron beam for irradiating the evaporation material 5 is made into a spot shape having a diameter as small as possible in order to increase the current density as much as possible and efficiently heat and evaporate.

Reference numeral 10 is a deflecting system for two-dimensionally scanning the electron beam E on the evaporation material 5, which is composed of, for example, a toroidal coil.

Now, as shown in FIGS. 1 and 2, each magnetic pole 6
When the electron beam E is generated from the electron gun 2 in the state where the magnetic field B in the arrow direction is formed by a and 6b, the electron beam is deflected by 180 degrees by the magnetic field B and irradiates the evaporation material 5, so that the evaporation material is heated. Is evaporated. At this time, if the electron beam E is two-dimensionally scanned on the evaporation material 5 by the deflection system 10, the evaporation material region can be expanded.

However, in the system in which the electron beam is two-dimensionally scanned on the evaporation material by the deflection system as described above,
Generally, the crucible has a cylindrical shape, whereas the electron beam is scanned in a rectangular shape. Therefore, a portion of the evaporation material that is not scanned is formed, and the evaporation material remains in the portion that is not scanned. Therefore, the evaporation material has to be exchanged even though there is a portion that has not been evaporated, so that the utilization efficiency of the evaporation material is poor. Also, there is a limit to the scanning range of the evaporation material by the electron beam, and there is a limit to the amount of evaporation at one time.

Therefore, recently, as shown in FIG.
With the (crucible 4) rotated in the direction of arrow C,
The electron beam E is heated and vaporized while reciprocating from the rotation center O of the vaporized material 5 along the radial direction (X direction) to the outer peripheral portion of the vaporized material as shown by the dotted line Sa in the figure. It is being appreciated.

In this way, the electron beam E can be irradiated to the entire evaporation material 5, so that the evaporation material can be consumed without waste. Further, since the scanning of the electron beam is not a two-dimensional scan but a reciprocating motion, it is relatively easy to increase the moving distance. Therefore, a crucible having a large diameter can be used, and a large amount of evaporation material can be heated and evaporated at one time.

[0009]

By the way, the evaporation material 5
The shape of the electron beam E for irradiating the upper part is constant without changing within the moving range of the electron beam as shown by the solid line Sa and the dotted line Sb in FIG. 3, and the size thereof is very small for the reason described above. You are using the one on the spot.
In other words, it reciprocates on the evaporation material with an electron beam having a very large constant current density.

On the other hand, when the evaporation material 5 is rotated, its peripheral speed increases in proportion to the distance from the center of rotation. That is, the center O of rotation of the evaporation material hardly rotates. Therefore, when the electron beam with a very large constant current density is moved on the evaporation material as described above, the rotation center part which is hardly rotating is heated more strongly than the outer peripheral part and evaporates earlier, so that the evaporation material As a result, uneven evaporation occurs, making it impossible to form a uniform evaporated film, and it becomes impossible to evenly evaporate the evaporation material. In the worst case, a hole reaching the bottom of the crucible may be formed in the center of rotation of the evaporation material, and evaporation work may not be possible.

Therefore, in order to solve such a problem, the present invention eliminates uneven evaporation and forms a uniform vapor deposition film when the evaporation material is heated and vaporized while being rotated, and the evaporation material is evenly vaporized. It is an object of the present invention to provide an evaporation method that can be performed.

[0012]

In order to achieve the above object, the present invention irradiates a rotating vaporized substance with an electron beam to vaporize the vaporized substance, and reciprocates the electron beam in a radial direction from a rotation center of the vaporized substance. In the method of evaporating while moving, the shape of the electron beam with which the evaporative substance is irradiated is changed between the rotation center part of the evaporating substance and the outer peripheral part thereof to change the current density of the electron beam on the evaporating substance and evaporate. It is characterized by that.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 4 is a schematic structural view showing an example of an apparatus for carrying out the electron beam evaporation method according to the present invention. The same reference numerals as those in FIGS. 1, 2 and 3 indicate the same constituent elements. Is.

In this embodiment, what is different from FIGS. 1 and 2 is that the crucible 4 is rotatably incorporated into the evaporation source body 1 by a motor or the like (not shown), and a pair of magnetic poles 6
The auxiliary magnetic pole pieces 11a and 11b are attached to the surfaces of a and 6b facing each other so as to face each other.

By thus providing the auxiliary magnetic pole pieces 11a and 11b, the magnetic field formed near the outer circumference of the crucible 4 (evaporation material 5) in the X direction scanned by the electron beam becomes strong. In addition, the magnetic flux flowing between the auxiliary pole pieces causes the second
The magnetic field formed between the open ends of the pole pieces 9a, 9b is weakened. As a result, the magnetic poles 6a and 6b and the second magnetic pole piece 9
The deflection magnetic field B formed between a and 9b has such a distribution that the rotation center O of the evaporation material 5 is small in the X direction and gradually increases toward the outer circumference. Therefore, as shown in FIG. 5, when the electron beam E approaches the rotation center O of the evaporation material 5 by the deflection system 10, the second pole piece 9a,
Since the magnetic field formed at the open end of 9b is weak, the focusing action in the X direction on the electron beam is weakened, and the shape of the electron beam becomes elliptic as shown by the solid line Sb ', so that the current density becomes small. On the contrary, when the electron beam approaches the outer peripheral portion of the evaporation material 5 along the X direction, the auxiliary magnetic pole pieces 11a, 11
Since the strength of the magnetic field gradually increases due to b, the focusing action in the X direction on the electron beam gradually becomes stronger, and the shape of the electron beam becomes a spot shape as shown by the dotted line Sa ′, so that the current density becomes high. Therefore, the current density of the electron beam on the evaporation material can be continuously changed so as to increase as the distance from the rotation center increases, so that the evaporation material can be made uniform even if the rotating evaporation material is irradiated with the electron beam. It can be heated and evaporated.

The above description is one example of the present invention, and various modifications can be considered in the implementation. For example, when the auxiliary magnetic pole pieces 11a and 11b are provided as shown in FIG.
Even if the magnetic pole pieces 9a and 9b are removed, the shape of the electron beam E is irradiated on the ellipse at the rotation center O portion of the evaporation material 5 and on the spot at the outer peripheral portion thereof as shown in FIG. It was confirmed by experiments that this can be done. If the second magnetic pole piece is eliminated in this way, it becomes possible to easily automate the dynamic supply of the vaporized material, and the vaporized substance adhering to the second magnetic pole piece is separated and falls into the crucible. It has the effect of preventing contamination.

Further, in the above embodiment, in order to change the shape of the electron beam scanning the evaporation material, the magnetic poles 6a,
Although the case where the auxiliary magnetic pole pieces 11a and 11b are added to 6b is shown, the present invention is not limited to this, and the gap between the open ends of the second magnetic pole pieces may be widened without providing the auxiliary magnetic pole piece, for example. This is because the magnetic field generated between the magnetic pole pieces becomes weaker as the distance between the magnetic pole pieces becomes wider, and the focusing action in the X direction becomes weaker as the electron beam E moves from the outer peripheral portion of the crucible 5 toward the rotation center O.

Further, in the above-mentioned embodiment, the electron beam evaporation source of the 180-degree deflection type is described, but the present invention is not limited to this, and the electron beam evaporation source of the 270-degree deflection type can be similarly applied.

[0020]

As described above, since the current density of the electron beam can be changed at the rotation center of the evaporation material and its outer peripheral portion, the rotation center of the evaporation material is heated strongly as in the conventional case. Can be prevented. As a result, it is possible to form a uniform vapor deposition film on the evaporation material without causing unevenness of evaporation and to evaporate the evaporation material uniformly. Further, it is possible to eliminate the worst condition in which a hole reaching the bottom of the crucible is formed at the center of rotation of the evaporation material and the evaporation work cannot be performed.

[Brief description of drawings]

FIG. 1 is a plan view for explaining a conventional device.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a diagram for explaining the operation of the conventional device.

FIG. 4 is a schematic configuration diagram showing an example of an apparatus for carrying out the electron beam evaporation method according to the present invention.

FIG. 5 is a diagram for explaining the operation in the present invention.

FIG. 6 is a schematic configuration view showing another example of the apparatus for carrying out the electron beam evaporation method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 evaporation source main body 2 electron gun 3 beam passage hole 4 crucible 5 evaporation material 6a, 6b magnetic pole 7 yokes 8a, 8b first magnetic pole piece 9a, 9b second magnetic pole piece 10 deflection system 11a, 11b auxiliary magnetic pole piece

Claims (1)

[Claims] 1. When irradiating a rotating evaporation material with an electron beam to evaporate the same, the method is to evaporate the electron beam while reciprocating in the radial direction from the rotation center of the evaporation material, and irradiating the evaporation material. An electron beam evaporation method, characterized in that the shape of an electron beam is changed between a rotation center part and an outer peripheral part of the evaporation substance to change the current density of the electron beam on the evaporation substance to evaporate.