JPS62180068A - Device for heating and evaporating electron beam - Google Patents

Abstract

PURPOSE:To eliminate the need for material replenishment during operation by the use of a large-capacity crucible and to prevent bumping by the melting away of the compd. film on a melting surface by providing a means for rotating the crucible and deflecting an electron beam and uniformly heating the electron beam. CONSTITUTION:A coil 31 is excited by an excitation power source 32 to generate magnetic lines of force between arms 30a and 30b and to exert the force toward the right side of the figure by Fleming's left-hand rule to the electron beam 11. The output voltage of the power source 3 is increased and decreased according to a pre scribed period to periodically fluctuate the magnitude of the force that the electron beam 11 receives so that the irradiation spot SP of the beam 11 on a material to be heated and evaporated (evaporating source) 4 is moved back and forth in a route lconnecting the rotating center part and peripheral edge of the melting surface of the evaporating source 4. On the other hand, the crucible 20 is rotated by a motor 22 and a gear box 21 to rotate the melting surface. The spot SP eventually moves over the entire surface of the melting surface, thereby uniformly heating the surface. The compd. film is immediately heated to melt and is thereby annihilated by the movement of the spot SP even if the compd. is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an electron beam heating/evaporation device suitable for use as a heating source for, for example, a vacuum evaporation device or an ion blating device.

"Conventional technology" In vacuum evaporation equipment and ion blating equipment,
An electron beam heating and evaporation device is provided to heat the evaporation source.

Here, as an example, a conventional electron beam heating/evaporation device used in an ion blating device will be described. FIG. 3 is a schematic configuration diagram showing the configuration of a general ion brating device, and in the figure, 1 is an airtight tank;
2 is a substrate; 3 is a substrate holder that supports the substrate 2; At a position facing the substrate 2, there is an evaporation source (heated/generating substance) 4.
A crucible 5 for holding a is provided, and an electron beam heating/evaporation device 6 is provided below the crucible 5. This electron beam heating/evaporation device 6 includes a filament 7 for emitting thermoelectrons, an anode 8 for accelerating the emitted thermoelectrons, a filament power source (AC power source) 9, and an anode power source (DC high voltage power source) 10. It consists of etc. In this case, the anode 8 is grounded as shown, but
Since the filament 7 is at a positive potential due to the power supply IO, when thermoelectrons are emitted from the filament 7, these thermoelectrons are accelerated and emitted by the anode 8 and become an electron beam +1. Then, the electron beam It is bent by a magnetic field (not shown) and irradiated onto the evaporation source 4, whereby the evaporation source 1 is heated and evaporated. The spot diameter of the electron beam of this evaporation source 4'' is generally set small, and the spot position is as shown in Fig. 4 (a) and (b).
It is set to be located at the center of the crucible 5 as shown in SP. The reason for reducing the spot diameter in this way is as follows. In other words, in an electron beam heating/evaporation device, electrons are accelerated by an electrostatic field and collide with the surface of the +4 material, thereby converting the kinetic energy of the electrons into thermal energy. This is because it is more advantageous to reduce the power density and increase the power density for heating. Further, the reason why the spot is located at the center of the crucible 5 is due to thermal efficiency. At this time, if the spot diameter is made small as described above, the capacity of the crucible 5 cannot be increased too much due to heat balance, and as a result, the capacity of the crucible 5 is set to be relatively small.

In Figure 3, 15 is ionization 7ti +u
, 16 is a power source for the ionization 'X1i electrode (positive potential), I7 is a power source for the weir plate holder (negative potential), I8 is an inlet pipe for reactive gas, and 19 is an exhaust pipe.

"Problems to be Solved by the Invention" By the way, the above-mentioned conventional device had the following drawbacks.

■Because we use a small crucible due to heat balance,
There are only a few materials that can be heated and evaporated at one time, and in order to heat and evaporate a large amount of material, materials must be replenished during operation.

■Since the irradiation position of the electron beam is fixed, a compound is formed around it, and abnormal discharge is likely to occur, making it difficult to achieve stable heating and evaporation.

■Replenishing materials during operation may cause abnormal discharge or destabilize the evaporation rate.

■Since the melting surface is covered with a film of the compound, when the melting surface lowers, sudden boiling occurs due to the expansion of internal bubbles, causing abnormal discharge.

Furthermore, since the liquid level in the portion irradiated with the electron beam drops faster than in other portions, the above-mentioned boiling is likely to occur.

This invention was made in view of the above-mentioned circumstances, and is capable of electron beam heating that prevents the generation of compounds around the beam spot, eliminates the need to replenish materials, and prevents sudden boiling.・The purpose is to provide evaporation equipment.

"Means for Solving the Problems" In order to solve the above problems, the present invention accelerates thermoelectrons emitted from filaments to
In electronic heat heating and evaporation equipment that irradiates evaporated matter,
a crucible rotation mechanism that rotates the crucible; and an electron beam that deflects the electron beam so that the irradiation spot of the electron beam on the melting surface of the heated/evaporated material reciprocates on a path connecting the center of rotation and the periphery. and deflection means.

``Effect J When the crucible rotates, the spot of the electron beam reciprocates along the path connecting the rotation stopping part and the periphery.
The melting surface is heated evenly. Therefore, evaporation is performed evenly from the entire molten surface.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing the structure of an embodiment of the present invention, and parts corresponding to those shown in FIG.

In the figure, 20 is a crucible, the crucible is connected to a gearbox 21 via a vertical shaft, and this gearbox 21
The driving force of the motor 22 is transmitted to.

Therefore, when the motor 22 rotates, the crucible 20 rotates to the left rather than to the right in the drawing. In this case, the rotation speed of the crucible 20 is set to a relatively low speed, and the crucible 20 is set at a relatively low speed.
The lower part of 0 is water-cooled by cooling water discharged through a pipe 24. Next, 30 is a U-shaped core portion (4) having arms 30a, 30b extending in the horizontal direction.
The arms 30a and 30b face each other with the electronic beam 11 in between. A coil 31 is wound around the core 30 and is connected to an excitation power source 32. Excitation power supply 32
is a DC power supply circuit that increases or decreases its output voltage according to a predetermined cycle.

In this case, the core 30, coil 31, and excitation power source 32 constitute an electron beam deflection device.

Next, the operation of this embodiment with the above configuration will be explained.

First, when the coil 3I is excited, magnetic lines of force as shown are generated between the arms 30a and 30b, and the electron beam II receives a force to the right in the drawing due to Fleming's left hand rule. When the output voltage of the excitation power source 32 increases or decreases according to a predetermined period, the magnitude of the force applied to the electron beam 11 changes periodically, and as a result, the spot SP of the electron beam 11 on the evaporation source 4 is As shown in the figure, the evaporation source 4 reciprocates along a path Q that connects the center of rotation of the molten material and the peripheral edge.

On the other hand, since the melting surface rotates according to the rotation of the crucible 20, if the spot SP moves back and forth along the path Q in a double series, the spot S I) will move all over the entire surface of the melting surface. . Therefore, the entire melting surface is uniformly heated. Also, if a compound were to occur,
Since the spot SP is f-hyperactive, the compound (film) is immediately heated and melted and disappears.

In this example, the spot SP is the closest to the rotation center 0 of the molten surface, is slightly eccentric from the rotation center 0 as shown in Fig. 2, and the spot SP is the closest to the periphery. However, he does his best to avoid having concubines on the periphery. This is because the area around the spot SP is heated by thermal conduction, so this heating effect is taken into account and the movement stroke of the spot SP is not wasted.

Further, in the above embodiment, the crucible 5 is constantly rotated, but it may be rotated intermittently as long as uniform heating of the molten metal is not affected.

Furthermore, in the above embodiment, the electron beam l! was deflected by a magnetic field, but due to the electric field, the electric field beam 1! Alternatively, as the excitation power source 32, an AC power source that outputs a current at a predetermined frequency may be used. In short, the initial position and deflection range of the spot SP may be set so that the spot SP reciprocates on the path Q.

"Effect of the Invention J As explained above, according to the present invention, in the electron beam heating/evaporation apparatus that accelerates thermionic electrons emitted from a filament and irradiates the heated/evaporated material in the crucible, the crucible is heated. The crucible rotation mechanism that rotates the
Since the electronic beam deflecting means is provided for deflecting the l'iq electron beams so that the irradiation spot of the single beam on the melting surface of the evaporated material reciprocates on a path connecting the rotation center and the periphery, the following will be described. The effects described can be obtained.

■Since the molten surface inside the crucible can be heated uniformly, the film of the compound can be melted and removed. This prevents abnormal discharge, provides stable heating, and prevents evaporation over a long period of time. I have something to do.

■Since uniform heating of the melting surface is possible, a large-diameter crucible can be used, and the capacity of the crucible can be increased to heat and evaporate a large amount of material at once.

Therefore, there is no need to replenish materials during operation.
Abnormal discharge caused by material replenishment can be prevented and continuity of operation can be ensured.

■Since the compound film on the molten surface is removed uniformly, sudden boiling does not occur when the molten surface decreases.

■Since the melting surface is heated evenly, the evaporation period can be made uniform.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the configuration of an embodiment of the present invention;
Figure 2 is a plan view of the crucible to show the moving state of the irradiation spot SP of the electron beam II, Figure 3 is a schematic configuration diagram showing the configuration of a conventional electron beam heating/evaporation device, and Figure 4 (A). , (b) are a cross-sectional view and a plan view of a crucible in a conventional electron beam heating/evaporation device, respectively, showing the beam spot position. 21... Gear box (crucible rotation speed structure), 22...
... Motor (crucible rotating rock structure), 30 ... Core, 31 ... Coil, 32 ... Excitation 7vL source (30.31°32 above is electron beam deflection means). Figure 1

Claims (1)

[Claims] In an electron beam heating/evaporation device that accelerates thermoelectrons emitted from a filament and irradiates a heated/evaporated substance in a crucible, a crucible rotation mechanism that rotates the crucible;
It is characterized by comprising an electron beam deflecting means for deflecting the electron beam so that the irradiation spot of the electron beam on the molten surface of the heated/evaporated material reciprocates in a path connecting the center of rotation and the periphery. Electron beam heating and evaporation equipment.