JPH07201297A - Evaporation source - Google Patents

Abstract

PURPOSE:To improve the service life of a filament by constituting the filament of an electron gun in the shape so that the part corresponding to the deflecting orbit of the positive ion generated when the evaporating substance is evaporated becomes blank. CONSTITUTION:A filament(FL) 1 is of flat type with conugation, and the lower part below the cener of FL1 where the positive ion flow 8 to be generated when the evaporating substance 6 such as titanium is evaporated passes is constituted in the shape to form a space free from the wires. When this FL1 is mounted on the electron gun of an electron beam (EB) evaporating device, the part corresponding to the lower part of the axis of the deflected orbit of the EB4 is made the part which is the space of the FL1. This constitution allows the positive ion flow 8 to be converged by the electric field between the FL1 and an anode 2, and the electric field between the FL1 and the grid when the EB4 is guided on the substance 6 by a deflecting magnet 3, and most of the EB4 passes through the space part of the FL1. Thus, the sputter by the positive ion of the FL1 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporation source adapted to apply an electron beam from an electron gun to an evaporation material to evaporate the evaporation material.

[0002]

2. Description of the Related Art Generally, in production by a continuous vapor deposition method, a method using an electron beam (hereinafter abbreviated as EB) as an energy source is suitable from the viewpoint of productivity. By heating the tungsten filament, the electrons are heated and the electrons fly out and are accelerated by the electric field to become EB. Further, for example, when titanium vapor deposition is continuously performed, vapor deposition may be performed in a low vacuum of about 10 ⁻⁴ Torr in order to increase the vapor deposition surface area. For example, as shown in FIG. 2, an evaporation material 6 such as titanium is put in a crucible 5, and the crucible 5 is used as an anode. Electrons from a cathode filament 1 of an electron gun are accelerated by an anode 2 and a EB 4 is generated by a deflection magnet 3. Are introduced onto the vaporized substance 6 such as titanium, and the vaporized substance 6 such as titanium is vaporized by impact with the EB 4, and is attached to the base material 7 arranged above the crucible 5. In order to avoid damage and contamination of the filament 1 caused by the vapor generated by the vaporized substance 6 hitting the filament 1 of the electron gun, the filament 1 is arranged at a position where it is not directly exposed to the vapor, and the electrons from the filament 1 are deflected as described above. The magnetic field formed by the magnet 3 is deflected to guide it to the vaporized substance 6 such as titanium.

[0003]

[Problems to be Solved by the Invention]
As the filament of the electron gun that evaporates the vaporized substance by the impact of, a large one is generally used so that a beam of low voltage and high power (that is, a beam of large beam current) can be obtained. For example, a disk-shaped one,
Wave shapes as shown in FIGS. 6A and 6B, and FIGS.
A spiral shape as shown in is used. However, such a filament is broken during the vapor deposition operation, that is, the vaporized substance 6 such as titanium is vaporized by the impact of the EB 4, and at this time, a part of vapor or an atmospheric gas (for example, argon gas) is evaporated. Gas) is ionized by the bombardment of EB, and the cations are directed along the deflection trajectory of EB between the filament 1 and the vaporized substance 6 such as titanium toward the filament 1 to which a negative high voltage is applied, and It collides with this filament and spatters it to break the wire. At this time, since the cation has a mass much larger than that of the electron, it cannot be completely deflected. Therefore, the orbit (positive ion flow along the orbit indicated by the dotted line 8 in FIG. 2) in which the positive ions are deflected and accelerated becomes a large orbit outside the deflection orbit of EB4, and collides with the filament 1 through this orbit. To do. Therefore, as shown by the dotted line 9 in FIG. 3, the lower part than the center of the filament 1 is broken by the ion bombardment.

When such a disconnection occurs, the filament is replaced by cooling the crucible of the vapor deposition apparatus and the vapor deposition material so as not to cause deterioration such as oxidation, and then releasing the vacuum to return it to normal pressure. Then, the filament must be replaced with a new one, the vacuum evaporation conditions before disconnection must be restored, and evaporation must be restarted. Therefore, a long work loss occurs and the disconnection causes the deposited film to become defective. In some cases, it is economically and operationally disadvantageous, and in particular, such shortening of the filament life due to disconnection cannot withstand continuous use in production by the continuous vapor deposition method. The short life of the filament shortens the continuous vapor deposition time, resulting in a problem that workability and productivity are extremely poor.

The present invention has been made to solve the above problems, and an object thereof is to provide an evaporation source capable of extending the life of the filament of an electron gun.

[0006]

In order to solve the above-mentioned problems, the evaporation source of the present invention accelerates an electron beam from an electron gun having a filament formed in a plane perpendicular to the electron emission direction and appropriately deflects it. In the evaporation source adapted to evaporate the evaporated substance, the filament has a shape in which a portion corresponding to a deflection orbit of cations generated when the evaporated substance is evaporated is blank. .

[0007]

The filament of the electron gun used in the evaporation source of the present invention has a shape in which the portion corresponding to the deflection orbit of the cations generated during the evaporation of the evaporated material is blank, so that it is about 10 ^-4 Torr. EB in a low vacuum atmosphere
The cations do not collide with the filament during vapor deposition. Therefore, since the filament is not ion bombarded, the filament is not broken for a long time.

[0008]

1 (a) and 1 (b) are a plan view and a perspective view showing a shape of a filament of an electron gun which constitutes a part of an evaporation source in an embodiment of the present invention, and FIG. It shows another shape. Then, a filament of this shape is attached as a filament of an electron gun of the EB vapor deposition device shown in FIG. 2 in a direction in which cations do not collide with this filament.

Since the filament 1 is heated by energization as a resistor and emits electrons, in order to obtain the same EB output under the same conditions as the conventional filament, the generation amount, the generation range and the central value of the EB4 at the same mounting position. Must be the same, and there are restrictions on wire diameter, length, and shape. Further, since the filament 1 is heated to a high temperature, there is a restriction on the shape in which the filament 1 is not damaged by thermal stress. Further, the electrons emitted from the entire surface of the filament 1 as seen from the accelerated anode 2 side of the EB 4 are the crucible 5
Becomes an effective electron beam of EB4. Moreover, in the filament 1, it is easier to control the position of the EB 4 when the respective portions are equidistant from the respective portions of the anode 2 facing each other.
Since it is more efficient that the EB4 energy is concentrated when the respective parts of the filament 1 are densely packed with each other, a planar wave shape or a spiral shape is obtained, and in the present invention, accelerated cations are generated. Filament 1 to avoid being bombarded by ion bombarding filament 1
The shape of is improved. The present invention has been found as a result of various studies under such conditions. That is, for example, the filament 1 as shown in FIGS. 1A and 1B and FIG. 4 has a planar wavy shape, but a portion through which cations generated during evaporation of the evaporation material 6 such as titanium pass (FIG. 3 and the portion indicated by the dotted line 9 in FIG. 4, that is, the lower part from the center of the filament 1 is formed in a shape having no line, that is, a blank shape. In addition, it has a shape without corners so that it will not be broken even if it receives heat stress.

When such a filament 1 is attached to the electron gun of the EB vapor deposition apparatus shown in FIG. 2, the portion corresponding to the lower portion (outside of the arc) of the central axis of the deflection trajectory of the EB 4 becomes the space of the filament 1. To be By doing so, the electrons from the filament 1 of the electron gun are accelerated by the anode 2 and guided by the deflection magnet 3 onto the evaporation material 6 such as titanium. At this time, in practice, the electrons from the filament 1 are focused by the electric field between the filament 1 and the anode 2 and the electric field between the filament 1 and the grid (not shown),
The focused EB 4 is guided onto the evaporation material 6.
Then, at this time, a part of the vapor of the vaporized substance 6 and the atmospheric gas (for example, argon gas) are ionized by the impact of the EB 4, and the cations are generated in the filament 1 and the anode 2.
An ion deflection orbit outside the deflection orbit of the EB 4 between the filament 1 and the vaporized substance 6 such as titanium, which is accelerated by a negative high voltage in between (cations along this orbit indicated by the dotted line 8 in FIG. 2). Flow) in the direction of the filament 1. The cations accelerated along the ion deflection orbit are the filament 1 and the anode 2
It is focused by the electric field between them and the electric field of the filament 1 and the grid (not shown), and most of it is passed through the filament portion (space portion) along the ion deflection orbit. Therefore, sputtering by the cations of the filament 1 does not occur.

Table 1 shows the case where the evaporation material 6 such as titanium is vapor-deposited on the substrate 7, the case where the filament of the present invention is used, and the conventional spiral shown in FIGS. 6 (a) and 6 (b). The data when the filamentous filament is used are shown below. The vacuum condition is such that the degree of vacuum is 5.0 × 10 ^-4 Torr, the vapor deposition is carried out at an EB output of 6.0 KW in an argon gas atmosphere, and the filament is cut. Expressed the time.

[0012]

[Table 1]

As is clear from the data shown in Table 1, the filament of the present invention has a life of 10 times or more that of the conventional filament.

[0014]

As described above, according to the present invention, an electron beam from an electron gun having a filament formed in a plane perpendicular to the electron emission direction is accelerated, appropriately deflected and applied to an evaporated substance. In the evaporation source adapted to evaporate the evaporation material, since the filament has a shape in which a portion corresponding to a deflection orbit of cations generated at the time of evaporation of the evaporation material becomes blank, E in a low vacuum atmosphere
Even if B vapor deposition is performed, cations will not collide with the filament, and thus the filament will not be ion bombarded, so that the filament will not be broken for a long time and the life of the filament can be remarkably extended. Become. As a result, not only is it economically and operably remarkably advantageous, but also the continuous vapor deposition time by the continuous vapor deposition method is lengthened, and workability and productivity can be remarkably improved.

[Brief description of drawings]

FIG. 1A is a plan view showing a shape of a filament of an electron gun which constitutes a part of an evaporation source according to an embodiment of the present invention. FIG.

FIG. 2 is a schematic configuration diagram of an EB vapor deposition device.

FIG. 3 is an explanatory plan view for explaining a cutting position of a conventional EB filament.

FIG. 4 is an explanatory plan view showing another example of the shape of the filament of the electron gun forming a part of the evaporation source in the embodiment of the present invention.

5A is a plan view of a conventional corrugated filament, and FIG. 5B is a perspective view of the same.

FIG. 6A is a plan view of a conventional spiral filament, and FIG. 6B is a perspective view of the same.

[Explanation of symbols]

 1 Filament 2 Anode 3 Deflection magnet 4 EB 5 Crucible 6 Evaporated substance 7 Base material 8 Cation flow

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyoshi Kanzaki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Iwa Tajima, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. An evaporation source for accelerating an electron beam from an electron gun having a filament formed in a plane perpendicular to the electron emission direction, appropriately deflecting the electron beam, and applying the electron beam to the evaporated substance to evaporate the evaporated substance. 2. The evaporation source, wherein the filament has a shape in which a portion corresponding to a deflection orbit of cations generated at the time of evaporation of the evaporation material is blank. 2. An evaporation source for accelerating an electron beam from an electron gun having a filament formed in a plane perpendicular to the electron emission direction, deflecting the electron beam appropriately, and applying the electron beam to the evaporated substance to evaporate the evaporated substance. In the evaporation source, the filament is formed in a shape in which a central portion outside an arc formed by the deflection of the electron beam is blank.