JP3789667B2 - Vacuum arc evaporation source and vacuum arc evaporation apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum arc evaporation source and a vacuum arc evaporation apparatus provided with the vacuum arc evaporation source.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a vacuum arc vapor deposition apparatus is known that generates arc discharge using a vaporized substance as a cathode in a vacuum chamber, vaporizes and ionizes the cathode material by the energy of arc current, and deposits a film on a substrate.
In such a vacuum arc vapor deposition apparatus, it is inevitable that molten particles having a diameter of several μm or more, which is much larger than that of evaporated particles / ionized particles, are generated, and this is mixed into the film, whereby the surface roughness of the film is increased. It is a disadvantage that it causes deterioration of the film and nonuniformity of the film composition.
[0003]
There has been proposed a solution to solve such a problem caused by molten particles by generating a magnetic field. For example, Japanese Patent Laid-Open No. 2-194167 discloses a structure in which an air core coil coaxial with the evaporation surface is provided between the evaporation surface and the substrate (prior art 1). According to this configuration, the electrons in the plasma are wound around the magnetic field generated by the air-core coil, and the plasma flows along the magnetic field lines while rotating, so that the plasma reaches the substrate. On the other hand, this induction effect does not act on neutral molten particles, and ions are selectively guided to the substrate, so that the number of molten particles directed toward the substrate can be relatively reduced. .
[0004]
Further, JP Tokuoyake flat 5-48298, a permanent magnet for generating a magnetic field component parallel to the cathode surface is arranged in the cathode back to a circular orbit path of the arc motion by rotating the permanent magnet Are disclosed. Then, the horizontal component of the magnetic field generated by the permanent magnet is increased by the magnetic field generated by the solenoid coil surrounding the cathode (prior art 2).
[0005]
[Problems to be solved by the invention]
However, in the case of the prior art 1, the coil is provided at an intermediate position between the substrate and the evaporation surface, and the magnetic field generated by the coil acts so as to be inward in the radial direction of the evaporation surface. In this case, the arc spot tends to be near the center of the evaporation surface, and the evaporated substance is not consumed uniformly.
On the other hand, in the case of the prior art 2, the coil is disposed so as to surround the evaporation surface, and at first glance, it is considered that the magnetic field lines act perpendicularly to the evaporation surface. However, this coil is for increasing the parallel component of the magnetic field lines generated by the permanent magnet disposed on the back surface of the evaporating material, and for canceling out the vertical component of the magnetic field lines generated by the permanent magnet. .
[0006]
That is, this coil is provided as an auxiliary to the permanent magnet, and in the prior art 2, the coil does not act on a magnetic field line perpendicular to the evaporation surface.
The present invention has been made in view of such circumstances, and provides an evaporation source capable of reducing the number of molten particles reaching the substrate by a magnetic field and reducing the occurrence of arc spots. For the purpose.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention takes the following technical means. That is, the feature of the vacuum arc evaporation source according to the present invention includes a magnetic field generation source that surrounds the evaporation substance so as to generate only magnetic lines that intersect the evaporation surface of the evaporation substance substantially perpendicularly ,
The magnetic field generation source is composed of an annular magnet having annular magnetic poles at both ends in the axial direction and surrounding the evaporating substance, and the evaporation surface is positioned at an intermediate position between the N and S magnetic poles of the magnetic field generation source. The magnetic field source is disposed;
The magnetic field lines generated by the magnetic field generation source lie in a distribution that extends from one end surface of the annular magnet to the other end surface crossing the evaporation surface .
[0008]
According to such a configuration, the molten particles can be reduced by the magnetic field lines intersecting the evaporation surface as in the case of the prior art 1. And unlike the prior art 1, since a magnetic force line cross | intersects an evaporation surface substantially perpendicularly, an arc spot becomes difficult to be unevenly distributed in an evaporation surface, and an evaporation substance is consumed uniformly.
Here, the magnetic field lines do not need to intersect the evaporation surface completely perpendicularly, and the magnetic force lines substantially perpendicular to the evaporation surface include those within ± 30 degrees with respect to the normal line of the evaporation surface. Within this range, uniform consumption of the evaporated substance can be achieved to some extent and is within an acceptable range. Therefore, the magnetic field generation source may be arranged at a position where the magnetic field lines are in such a direction.
[0009]
Furthermore, it is preferable that the magnetic field generation source is arranged so that the direction of the magnetic force lines on the evaporation surface is within ± 10 degrees with respect to the normal line of the evaporation surface. In this case, the evaporated substance can be consumed more uniformly.
By the way, like the prior art 1, when generating a magnetic field with an air-core coil, it is inevitable that a magnetic field is generated in a wide range. In particular, a magnetic field extending long in the axial direction of the coil is generated. Such a long magnetic field acts to the position where the substrate is disposed, and there is a problem that this magnetic field affects the film structure in the film formation process on the substrate.
[0010]
In addition, when a plurality of evaporation sources are arranged for vacuum, there is a problem that a wide range of magnetic fields generated from a certain evaporation source can easily affect the evaporation characteristics of neighboring evaporation sources. Furthermore, when the evaporation source is arranged opposite to the vacuum vessel, there is a problem that a magnetic field extending long in the axial direction of the coil influences the opposite evaporation source.
On the other hand, a magnet having an annular magnetic pole as described above can prevent a magnetic field extending in the axial direction from being generated like an air-core coil.
Therefore, when this vacuum arc evaporation source is used in a vacuum arc vapor deposition apparatus, adverse effects on the substrate due to a magnetic field can be prevented. Further, when a plurality of evaporation sources are arranged in the vacuum vessel, it is possible to prevent a magnetic field from one evaporation source from adversely affecting other evaporation sources.
[0011]
Here, the magnet having an annular magnetic pole may be a permanent magnet formed in an annular shape or an electromagnet having a magnetic core formed so as to have an annular magnetic pole.
In addition, it is preferable that the magnetic field lines generated by the magnetic field generation source rapidly diverge in the outer diameter direction of the evaporated substance after passing through the evaporation surface of the evaporated substance.
In addition, as a magnetic field generation source for causing the magnetic field lines to intersect the evaporation surface substantially perpendicularly, as described above, the magnetic field generation source is arranged so that the evaporation surface is positioned at an intermediate position between the N and S magnetic poles of the magnetic field generation source. Is preferably arranged.
[0012]
Here, the intermediate position between the N and S magnetic poles may not be the center of both magnetic poles. However, if the magnetic field generation source is arranged so that the evaporation surface is positioned at approximately the center position of both the N and S magnetic poles of the magnetic field generation source, the direction of the magnetic force line is further equal to the normal direction of the evaporation surface. It becomes easy to do and is more suitable.
Moreover, it is preferable that the magnetic field generation source is configured by arranging a plurality of bar magnets having different magnetic poles at both ends in the longitudinal direction so that the magnetic poles are aligned in an annular shape . In this case, since the spread of the magnetic field in the axial direction of the magnetic field generation source is small, the influence on the substrate or other evaporation source can be effectively suppressed.
[0013]
The annular magnet includes a radially inner annular magnet that surrounds the evaporating substance, and a radially outer annular magnet that is coaxial with the radially inner annular magnet and surrounds the radially inner annular magnet so that the same pole faces in the same direction. It is preferable to be assumed to be.
In this case, the number of lines of magnetic force penetrating the evaporating substance is increased, that is, the magnetic field strength is increased, and the effect can be obtained more strongly.
In the present invention, the magnetic field generating source is a first annular magnet having magnetic poles on the inner and outer peripheral sides, and the inner and outer magnetic poles are different from the first annular magnet. And a second annular magnet juxtaposed in the axial direction of the first annular magnet.
[0014]
Such a configuration is preferable because the magnetic field spreads in the axial direction of the annular magnet is further reduced. In this case, if the outer peripheral sides of the first annular magnet and the second annular magnet are combined with a magnetic body, the magnetic field does not almost spread laterally, so a plurality of evaporation sources according to the present invention are provided in the vacuum vessel. In this case, the influence of the adjacent evaporation source can be eliminated.
In order to obtain the same effect, the magnetic field generation source may be configured as an annular magnet having a U-shaped cross section having both N and S magnetic poles inside the diameter.
Further, the evaporating substance is arranged so that the evaporating surface recedes from the evaporation start position ahead of the axial center of the magnetic field generation source to the rear of the axial direction center of the magnetic field generation source as the evaporating substance evaporates. Preferably it is.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 show a first embodiment of the present invention. As shown in FIG. 1, a vacuum arc vapor deposition apparatus 1 according to the present invention is provided with an evaporation substance 3 as a cathode in a vacuum vessel 2, and an arc discharge is generated between an anode (not shown) by an arc discharge power source 4. Thus, the evaporation substance 3 is evaporated and ionized, and a film is deposited on the coating processed product (substrate) 5.
[0016]
The evaporating material 3 constitutes one evaporating source unit 9 together with a magnetic field generating source 7 that generates a magnetic field that intersects the evaporating surface of the evaporating material 3 almost perpendicularly. In FIG. 1, one magnetic field generation source unit 9 is provided in the vacuum vessel 2, but it is preferable to provide a plurality of magnetic field generation source units 9 so as to surround the coating product 5 on the side wall of the vacuum vessel 2.
As shown in FIG. 3, the evaporating material 3 is formed in a disk shape, and the surface on the side of the coating processed product 5 is an arc evaporating surface 11. The magnetic field generation source 7 that constitutes the evaporation source 9 together with the evaporation substance 3 is configured as an annular permanent magnet having annular magnetic poles on both end surfaces in the axial direction (thickness direction). The magnetic field generation source 7 is arranged coaxially with the evaporating substance 3 so as to surround the evaporating substance 3. Further, the magnetic field generation source 7 is arranged so that the axial center position thereof and the position of the evaporation surface substantially coincide with each other, the end surface (front surface) on the coated material 5 side is the N pole, and the other end surface. Is the S pole. Note that the magnetic poles may be reversed.
[0017]
The magnetic field generation source 7 having such an arrangement generates a magnetic field as shown in FIG. FIG. 4 shows, as a comparative example, the state of the magnetic field when the coil 13 is arranged around the evaporating substance 3 as in the prior art. As shown in FIG. 4, in the case of the magnetic field generated by the coil 13, the magnetic force line M <b> 2 becomes a large loop that spreads widely in the axial direction of the coil 13. On the other hand, when the magnetic field generation source 7 is an annular magnet having an annular magnetic pole as in the present invention, the magnetic field lines M1 intersecting the evaporation surface 11 form a relatively small loop as shown in FIG. There is little extension of the magnetic field in the direction.
[0018]
Therefore, when the strength of the magnetic field crossing the evaporation surface 11 is the same, the magnetic field generated by the coil shown in FIG. 4 has a large spread and has a great influence on other places, but is generated by the annular magnet 7 shown in FIG. The applied magnetic field has a small spread and little influence on other places. Furthermore, since the magnetic field lines generated from the annular magnet 7 diverge rapidly in the radial direction after passing through the evaporation surface, the distribution of the plasma flow that is wound around the magnetic field lines is widened and the film thickness distribution is uniform over a wide range. Can be obtained.
In addition, since a permanent magnet is employed as the magnetic field generation source 7, the magnetic field strength of the same volume magnetic field generation source is larger than that of the coil. Therefore, since the evaporation surface and the flight path of the evaporated particles are placed in an area where the magnetic field strength is large, as shown in FIG. 5, the charged particles evaporated from the evaporating substance 3 fly along the magnetic field lines while wrapping around the magnetic field lines. Spiral movement is activated. As a result, activation of the film-forming particles evaporated from the evaporating substance 3 and the reaction gas is promoted, and a dense film having a high adhesion is obtained. The radius of the spiral motion of the charged particles is determined by the speed of the charged particles and the magnetic field strength, and the flight of charged particles is a collection of spiral flights of various radii.
[0019]
6A to 6D show images of the locus of the arc spot on the evaporation surface 11 in the present invention. Pattern of FIG. 6 (a) ~ (d) appears to run dam at every moment. Each pattern is a circular motion, and each pattern has a different circular radius. When the lines of magnetic force are substantially perpendicular to the evaporation surface 11, the locus of the arc spot becomes a revolving motion with a different radius at the moment in this way. Therefore, the evaporation position is compared with the case where the radius of the revolving motion is constant. Changes, and the evaporation surface is evenly consumed. Therefore, the evaporation surface is consumed while maintaining a state almost parallel to the evaporation surface at the time of a new article, and the use efficiency of the evaporation substance is very high. Note that the direction of the circular motion is reversed depending on the direction of the magnetic field lines.
[0020]
In addition, since the arc radius of the arc spot fluctuates randomly, the local temperature rise of the evaporated substance is suppressed, and the generation of molten particles is suppressed.
FIG. 7 shows, as a comparative example, an image of an arc spot when the lines of magnetic force are greatly inclined from the normal direction of the evaporation surface 11. As shown in FIG. 7A, when the magnetic field generation source 7 is largely shifted forward (on the side of the coated product 5) with respect to the evaporation surface 11 of the evaporation material 3, the magnetic lines of force on the evaporation surface 11 are greatly inclined inward. . Therefore, the arc spot is intensively discharged at the center of the evaporation surface 11.
[0021]
On the other hand, when it is largely displaced backward as shown in FIG. 7B, the magnetic lines of force on the evaporation surface 11 are greatly inclined outward. Therefore, the arc spot is discharged only at the edge of the evaporation surface 11, and the arc spot jumps out of the evaporating substance 3 and the arc discharge is likely to stop. In either case of FIGS. 7A and 7B, the evaporating substance 3 is not consumed uniformly, and the utilization efficiency is poor.
In order to prevent such an inconvenience, the direction of the magnetic force line on the evaporation surface 11 is preferably within ± 30 degrees with respect to the normal line of the evaporation surface, and more preferably within ± 10 degrees. The substance 3 and the magnetic field generation source 7 are arranged. The magnetic field lines are most preferably perpendicular to the evaporation surface 11, but the evaporation source unit 9 is preferably manufactured with the evaporation surface 11 positioned slightly forward from the axial center of the magnetic field generation source 7. . In this case, when the evaporation material 3 is consumed to some extent and the evaporation surface 11 is retracted, the axial center of the magnetic field generating source 7 and the position of the evaporation surface 11 coincide with each other. Since it is located slightly behind the axial center of the source 7, it is always possible to obtain a state in which the magnetic field lines are almost perpendicular to the evaporation surface until the evaporation material 3 is consumed from the new time.
[0022]
FIG. 8 shows an evaporation source 19 according to the second embodiment of the present invention. The magnetic field generation source 17 of the evaporation source 19 is configured to generate a magnetic field similar to the magnetic field generation source 7 of the first embodiment by arranging a large number of permanent magnets 21 in a ring shape. That is, a plurality of rod-shaped magnets 21 having magnetic poles at both ends in the longitudinal direction are arranged in an annular shape with the magnetic poles aligned, and substantially the same as the magnetic field generation source 7 in the first embodiment on both end faces in the axial direction. An annular magnet having an annular magnetic pole is configured. This magnetic field generation source 17 is disposed in the same manner as the magnetic field generation source 7 of the first embodiment, and acts on the evaporating substance 3 in the same manner as in the first embodiment.
[0023]
FIG. 9 shows an evaporation source 29 according to the third embodiment of the present invention. The magnetic field generating means 27 of the evaporation source 29 includes a radially inner annular magnet 30 configured and arranged in the same manner as the annular magnet 7 of the first embodiment, and a radially outer annular magnet 31 disposed on the radially outer side. It is configured. The radially outer annular magnet 31 is an annular magnet having magnetic poles at both ends in the axial direction, similarly to the radially inner annular magnet 30, and is configured to have substantially the same axial thickness. The radially outer annular magnet 31 is arranged coaxially with the radially inner annular magnet 30 and surrounds the radially inner annular magnet 30 so that the same magnetic pole faces in the same direction.
[0024]
As shown in FIG. 9, according to the magnetic field generating means 27 having such a configuration, the number of magnetic force lines penetrating the evaporating substance 3 is increased by the interaction between the annular magnets 30 and 31 as compared with the case of the inner diameter magnet 30 alone. That is, the magnetic field strength at the evaporation surface 11 is increased, and the effect of reducing the molten particles is obtained more strongly.
FIG. 10 shows an evaporation source 39 according to the fourth embodiment of the present invention. The magnetic field generating source 37 of the evaporation source 39 includes a first annular magnet 40 having magnetic poles on the inner peripheral side and the outer peripheral side, magnetic poles on the inner peripheral side and the outer peripheral side, and magnetic poles on the inner peripheral side and the outer peripheral side respectively. The second annular magnet 41 is different from the first annular magnet 40. The first annular magnet 40 and the second annular magnet 41 are coaxial and juxtaposed in the axial direction thereof.
[0025]
Specifically, the first annular magnet 40 has an N pole on the inner peripheral side and an S pole on the outer peripheral side. The second annular magnet 41 has an S pole on the inner peripheral side and an N pole on the outer peripheral side. The outer peripheral sides of the annular magnets 40 and 41 are connected by a magnetic body 42. Since the outer peripheral sides of both annular magnets 40 and 41 have different polarities, the magnetic body 42 is coupled by the magnetic force of both magnets 40 and 41.
As described above, an annular magnet having an annular magnetic pole can also be realized by the above configuration. That is, the magnetic field generated from the inner peripheral side of both annular magnets 40 and 41 is substantially the same as the magnetic field generating source 7 in the first embodiment, and the intermediate position of the inner peripheral magnetic poles of both annular magnets 40 and 41. When the evaporating surface 11 of the evaporating substance 3 is positioned on the surface, the magnetic field penetrates the evaporating surface 1 almost vertically.
[0026]
Moreover, according to this Embodiment, since the outer peripheral side of both the magnets 40 and 41 is connected by the magnetic body 42, a magnetic field does not generate | occur | produce on the outer peripheral side. Therefore, when a large number of the evaporation sources 39 are arranged adjacent to the vacuum vessel 2 as a unit, the influence of the magnetic field on the adjacent evaporation sources 39 can be effectively eliminated.
FIG. 11 shows an evaporation source 49 according to the fifth embodiment of the present invention. The magnetic field generation source 47 of the evaporation source 49 is constituted by an annular magnet having a U-shaped cross section having both N and S magnetic poles inside the diameter. Also in the present embodiment, the evaporating substance 3 is arranged so that the evaporation surface 11 is located at an intermediate position between the two magnetic poles, and the same effect as the fourth embodiment can be obtained.
[0027]
The present invention is not limited to the above embodiments. For example, the annular magnet as the magnetic field generation source does not need to surround the evaporating substance in an annular shape, and may enclose the evaporating substance in a polygonal shape.
[0028]
【The invention's effect】
As described above, according to the present invention, the number of molten particles can be reduced by the lines of magnetic force intersecting the evaporation surface. Since the lines of magnetic force intersect the evaporation surface substantially perpendicularly, the arc spot is less likely to be unevenly distributed on the evaporation surface, and the evaporated material is consumed uniformly.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a vacuum arc deposition apparatus according to a first embodiment of the present invention.
FIG. 2 is a sectional side view showing an evaporation source according to the first embodiment of the present invention.
FIG. 3 is a front view of an evaporation source according to the first embodiment of the present invention.
FIG. 4 is a sectional side view showing an evaporation source as a comparative example to the present invention.
FIG. 5 is a diagram showing a flight path of electrons from an evaporation source in the present invention.
FIG. 6 is an image diagram showing a locus of an arc spot on the evaporation surface in the present invention.
FIGS. 7A and 7B are a cross-sectional side view and a front view showing an evaporation source as a comparative example for the present invention, where FIG. 7A shows a magnetic field line facing inward and FIG. 7B shows a magnetic field line facing outward. .
8A and 8B show an evaporation source according to a second embodiment of the present invention, where FIG. 8A is a side view and FIG. 8B is a front view.
FIG. 9 is a sectional side view showing an evaporation source according to a third embodiment of the present invention.
FIGS. 10A and 10B show an evaporation source according to a fourth embodiment of the present invention, where FIG. 10A is a sectional side view, and FIG. 10B is a front view.
11A and 11B show an evaporation source according to a fifth embodiment of the present invention, in which FIG. 11A is a sectional side view, and FIG. 11B is a front view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vacuum arc evaporation apparatus 2 Vacuum container 3 Evaporation substance 7 Magnetic field generation source 9 Evaporation source (unit)
11 Arc evaporation surface 17 Magnetic field generation source 19 Evaporation source 21 Bar magnet 27 Magnetic field generation source 29 Evaporation source 30 Radial inner ring magnet 31 Radial outer ring magnet 37 Magnetic field generation source 29 Evaporation source 40 First annular magnet 41 Second annular magnet 42 Magnetic Body 47 Magnetic field source 49 Evaporation source

Claims (11)

An evaporating substance that serves as a cathode for arc discharge;
A magnetic field generation source that surrounds the evaporating material so as to generate only magnetic lines that intersect the evaporating surface of the evaporating material substantially perpendicularly ,
The magnetic field generation source is composed of an annular magnet having annular magnetic poles at both ends in the axial direction and surrounding the evaporating substance, and the evaporation surface is positioned at an intermediate position between the N and S magnetic poles of the magnetic field generation source. The magnetic field source is disposed;
A vacuum arc evaporation source characterized in that a magnetic field line generated by the magnetic field generation source has a distribution extending from one end face of an annular magnet to the other end face crossing the evaporation face .   2. The vacuum arc evaporation source according to claim 1, wherein the magnetic field generating source is arranged so that the direction of the magnetic force lines on the evaporation surface is within ± 30 degrees with respect to the normal line of the evaporation surface.   3. The vacuum arc evaporation source according to claim 2, wherein the magnetic field generation source is arranged so that the direction of the magnetic force lines on the evaporation surface is within ± 10 degrees with respect to the normal line of the evaporation surface. Magnetic lines by the magnetic field generating source, vacuum arc vapor deposition according to any one of claims 1 to 3, characterized that you rapidly diverge in the radially outward direction of the evaporated substance after passing through the evaporation surface of the evaporation material Source . Wherein the magnetic field generating source, according to any one of claims 1 to 4, characterized in that a plurality of bar magnets having different magnetic poles at both ends in the longitudinal direction aligning the orientation of the magnetic pole is formed by arranging the annular Vacuum arc evaporation source. The annular magnet is composed of a radially inner annular magnet that surrounds the evaporating substance, and a radially outer annular magnet that is coaxial with the radially inner annular magnet and surrounds the radially inner annular magnet so that the same pole faces in the same direction. The vacuum arc evaporation source according to any one of claims 1 to 4, wherein: The magnetic field generation source includes a first annular magnet having magnetic poles on the inner peripheral side and the outer peripheral side, and a magnetic pole on the inner peripheral side and the outer peripheral side that is different from the first annular magnet, and the first annular magnet. A second annular magnet juxtaposed in the axial direction of
Vacuum arc evaporation source according to any one of claims 1 to 4, characterized that you have been composed. 8. The vacuum arc evaporation source according to claim 7 , wherein the magnetic field generation source is configured by coupling outer peripheral sides of the first annular magnet and the second annular magnet with a magnetic material . Wherein the magnetic field generating source, vacuum arc evaporation source according to claim 1 in the radially inward side N, and wherein the U-shaped cross section of the annular magnet der Rukoto having S magnetic poles. The evaporation surface is claim 1, characterized that you retreat from the front of the evaporation start position than the axial center of the magnetic source with the evaporation of the evaporation material to the rear than the axial center of the magnetic field generating source The vacuum arc evaporation source according to any one of 9 . A vacuum arc vapor deposition apparatus comprising the vacuum arc evaporation source according to claim 1 .

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