JPH0559539A - Ion plating device - Google Patents

Abstract

PURPOSE:To provide the ion plating device which can generate an electric discharge with a low pressure and low voltage and can increase a discharge current. CONSTITUTION:An material 4 to be evaporated is irradiated with an electron beam E and is evaporated. The voltage is impressed to an electrode 13 to generate the discharge between this electrode 13 and a crucible 3 in the state of introducing reactive gases from a gas supplying device 11, by which the evaporated particles and the reactive gases are ionized. Magnetic field B1 in one direction are generated on the inner side of the electrode 13 by permanent magnets 14A to 14D and 15A to 15D which are embedded in the electrode and are arranged to face each other. The overhang magnetic fields are formed between the crucible 3 and the electrode 13 and, therefore, while the electrons from the material 14 to be evaporated are deflected, the electrons arrive at the electrode 13 and the many ions are generated. The discharge can, therefore, be started by the low pressure and low voltage. Most of the magnetic fields B1 of the part where the electrons arrive at the electrode 13 are approximately paralleled with the progressing loci of the electrons and, therefore, the electrons can be efficiently introduced to the electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion plating apparatus that ionizes an evaporated substance and collides it with a substrate to form a film.

[0002]

2. Description of the Related Art Recently, ion plating devices have been widely used in order to improve film quality and promote ionization of reaction gas.

FIG. 7 is a schematic view showing a conventional example of such an ion plating apparatus. Reference numeral 1 denotes a container, the inside of which is kept vacuum by a vacuum pump 2. Reference numeral 3 denotes a crucible placed at the bottom of the container, in which the evaporation material 4 is stored. 5
Is an electron gun provided on the side wall of the crucible, and 6 is a substrate arranged above the crucible so as to face each other, and is detachably held by a holder 7. Reference numeral 8 is a DC power supply for applying a negative voltage to this holder (substrate). Reference numeral 9 denotes a cylindrical electrode arranged between the crucible 3 and the substrate 6, to which a positive voltage is applied from the ionization power source 10. 11
Is a gas supply device.

[0004] In this configuration, the inside of the container 1, for example, ¹⁰ -5 to 10 by the vacuum pump 2 ^- evacuating to about ⁶ Torr. Next, a reaction gas such as N ₂ or O ₂ (Ar gas may be used) is introduced into the container from the gas supply device 11 until the inside of the container becomes about 10 ⁻⁴ Torr. Then, by operating an electron gun power supply and a deflector (not shown), the electron gun 5
The evaporation material 4 in the crucible 3 is deflected by deflecting the electron beam E from the
This evaporation material is applied to evaporate. In this state, when a positive voltage is applied to the electrode 9 from the ionization power source 10, secondary electrons and reflected electrons generated by the irradiation of the evaporation material with the electron beam are accelerated toward the electrode, and the electrons that reach this electrode are reached. A current corresponding to the number of flows into the crucible 3 and the electrode 9. Then, when the voltage applied to this electrode is increased, the current flowing between the crucible and the electrode is rapidly increased, and discharge is generated. The vaporized particles and the reaction gas are ionized by this discharge, and the ionized vaporized particles and the reaction gas are accelerated by the negative DC voltage applied to the holder 7 toward the substrate 6 and collide with and adhere to the substrate 6.
At this time, the vaporized particles and the reaction gas combine to form a vapor deposition film. If the vaporized particles and the reaction gas are ionized by generating the discharge in this way, an efficient thin film can be formed.

By the way, in recent years, it has been required to generate the above-mentioned discharge in an atmosphere having a pressure as low as possible and at a discharge voltage as low as possible, and to form a thin film in a state of a large discharge current. In order to satisfy such a requirement, generally, as shown in FIG. 8, a magnetic field is formed by incorporating a permanent magnet 12 in the vicinity of the electrode 9, and the magnetic field deflects electrons from the evaporation material to collide with the evaporation particles. An apparatus has been proposed in which ions are generated by increasing the number of times as much as possible. However, in such a device, as shown in the figure, for example, eight magnets 12A to 12H are radially arranged at equal intervals in the vicinity of the outer periphery of the cylindrical electrode 9, and the magnets are arranged so that the directions of polarities adjacent to each other are different. It is arranged so that it may be reversed. Therefore, the magnetic field formed inside the electrode 9 is distributed only in the vicinity of the inner wall of the electrode as indicated by the symbol H (such a magnetic field distribution is referred to as a multipolar magnetic field).

[0006]

According to such a magnet arrangement, the magnetic field formed by each magnet is a multipolar magnetic field H formed in the electrode and an overhanging magnetic field formed immediately below each magnet, Almost no overhanging magnetic field exists just above the crucible 3 located just below the center of the electrode. Therefore, the electrons from the evaporation material are very little affected by the magnetic field, and the amount of generated ions is very small. as a result,
At the start of discharge, there is a limit to lowering the pressure inside the container or lowering the discharge voltage. Therefore, a relatively large power supply is required as the discharge power supply.

On the other hand, most of the magnetic field formed by each magnet is distributed so as to be orthogonal to the electrons traveling from the evaporation material 4 to the electrode 9, so that the electrons act in the direction of moving them away from the electrode, and the magnetic field causes the electrons to move. The electrons reach the electrodes only in the portion where the eight magnets 12A to 12H that are substantially parallel to the traveling direction are placed. As a result, the amount of electrons that reach the electrode becomes extremely small, so that the voltage applied to the electrode 9 must be increased in order to obtain a desired discharge current and maintain a stable discharge, which is further large. A power source is required and cost increase cannot be avoided.

In view of the above points, the present invention has an object to provide an ion plating apparatus capable of generating a discharge at a low pressure and a low voltage and increasing a discharge current. It is a thing.

[0009]

In order to achieve the above-mentioned object, the ion plating of the present invention comprises means for heating and evaporating the evaporation material contained in the crucible, and the ion plating is arranged so as to face the crucible. A substrate held by a holder and an annular electrode to which a positive voltage is applied, which is placed between the crucible and the substrate, are provided, and the evaporated substance is ionized by discharging between the crucible and the annular electrode. In the device, a unidirectional magnetic field is formed inside the annular electrode.

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

[0011]

EXAMPLE FIG. 1 is a schematic configuration diagram showing an example of an ion plating apparatus according to the present invention, FIG. 2 is a plan view of an electrode used in the present invention, and the same reference numerals as those in FIGS. It shows an element.

That is, in the present embodiment, five permanent magnets 14A, 14B, 14 are provided inside the ring-shaped electrode 13 with the left and right sides thereof, that is, the straight line AA passing through the center O as the center.
C, 14D, 14E and 15A, 15B, 15C, 15
D and 15E are arranged as targets. Further, the magnetic poles of the magnets facing each other are arranged so that the right side has an N pole and the left side has an S pole. Further, a gas passage is formed inside the electrode and is connected to the gas supply device 11 through a pipe 16, and a large number of holes 17 for ejecting gas are formed on the inner inner wall of the electrode. There is. Reference numeral 18 is a cooling pipe fixed to the lower portion of the electrode, one end of which is connected to a cooling water supply port (not shown) and the other end of which is connected to a discharge port.

As shown in FIG. 2, if four magnets 14A to 14E and 15A to 15E are symmetrically incorporated in the electrode 13, a unidirectional magnetic field B1 from the right to the left is formed inside the electrode. To be done. Further, when the magnets are arranged so as to form such a magnetic field, an overhanging magnetic field B2 is formed immediately below the electrode 13, that is, between the electrode and the crucible 3, as shown in FIG. Therefore, first, the electrons e toward the electrode reach the electrode while being deflected without being straightened by the influence of the overhanging magnetic field B2, so that the number of times the electrons collide with the vaporized particles increases and a large number of ions are generated. As a result, the discharge can be performed with a low pressure and in a state where the voltage applied to the electrodes is low. FIG. 4 is an experimental result showing the relationship between the discharge pressure and the gas pressure. The circles use the unidirectional magnetic field of the present invention, the triangles use the conventional multipole magnetic field, and the squares do not use the magnetic field. The cases are shown respectively. As is clear from the figure, when the one in which a unidirectional magnetic field is formed as in the present invention is used, the discharge is performed with a low applied voltage in a low gas pressure atmosphere as compared with the case where no magnetic field or a multipolar magnetic field is used. It is clear that we can start.

Next, as is clear from FIG. 3, most of the magnetic field B1 at the portion where the electrons reach the electrode 13 is substantially parallel to the traveling trajectory of the electrons, so that the electrons can be efficiently guided to the electrodes. Therefore, a desired discharge current can be obtained without increasing the discharge voltage. Figure 5 shows electrode 1
3 is an experimental result showing the relationship between the voltage applied to the electrode 3 and the current flowing through the electrode. The circles use the unidirectional magnetic field of the present invention, the triangles use the conventional multipole magnetic field, and the squares use the magnetic field. It shows the cases where they do not. As is clear from the figure, it is clear that a large discharge current can be obtained at a lower discharge voltage as compared with the case of using no magnetic field or multipolar magnetic field by using the one in which a magnetic field in one direction is formed as in the present invention. Is.

The above description is an example of the present invention, and various modifications are conceivable in implementation. For example, in the above embodiment, the permanent magnets are used to form a magnetic field in one direction in the annular electrode, but electromagnets may be used instead of the permanent magnets. Alternatively, as shown in FIG. 6, the coils 19A and 19B may be directly wound around the electrode 13. here,
When the direction of the magnetic field formed in the electrode is set to be opposite to the traveling direction of the electron beam irradiating the evaporation material, the gas pressure and applied voltage at the start of discharge should be the lowest. It was confirmed by an experiment that this was possible.

In the above embodiment, the electron beam from the electron gun is deflected by about 270 ° to irradiate the evaporation material, but the electron beam and the evaporation material are 180 ° in substantially the same plane. It may be deflected to irradiate the evaporation material or may be irradiated directly to the evaporation material without deflecting the electron beam. Furthermore, a known heating means such as a heating coil or a laser may be used without using the electron beam. May be.

Furthermore, in the above embodiment, the DC voltage was applied to the electrodes to generate the discharge, but a high frequency voltage may be applied.

Furthermore, in the above-mentioned embodiment, the shape of the electrode is circular, but it may be elliptical or quadrangular.

[0019]

As described above, it is possible to provide an ion plating apparatus that can generate discharge at low pressure and low voltage and can increase discharge current.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an ion plating apparatus according to the present invention.

FIG. 2 is a plan view of an electrode used in the present invention.

FIG. 3 is a diagram for explaining the operation of the present invention.

FIG. 4 is a diagram showing a relationship between a gas pressure and a discharge starting voltage.

FIG. 5 is a diagram showing a relationship between a voltage applied to an electrode and a discharge voltage flowing through the electrode.

FIG. 6 is a plan view showing another example of the present invention.

FIG. 7 is a schematic configuration diagram for explaining a conventional example.

FIG. 8 is a schematic configuration diagram for explaining a conventional example.

[Explanation of symbols]

1: Container 2: Vacuum pump 3: Crucible 4: Evaporating material 5: Electron gun 6: Substrate 7: Holder 8: Power supply 9, 1
3: Electrode 10: Ion power supply 11: Gas supply device 12A
To 12H, 14A to 14D, 15A to 15D: Permanent magnets 16, 18: Pipes 17: Holes 19A, 19
B: Coil

Claims (1)

[Claims] 1. A means for heating and evaporating an evaporative substance contained in a crucible, a substrate placed facing the crucible and held by a holder, and placed between the crucible and the substrate. In a device having an annular electrode to which a positive voltage is applied and ionizing the vaporized substance by discharging between the crucible and the annular electrode, a unidirectional magnetic field is formed inside the annular electrode. An ion plating device characterized in that