JPH01312067A - Vacuum arc vapor deposition apparatus - Google Patents

Abstract

PURPOSE:To form good-quality films free from contamination with molten grains on substrates, respectively, by forming cusp-shaped magnetic fields in a vacuum treatment chamber, introducing the plasma of evaporated grains to substrates by means of the above magnetic fields, and also disposing the substrates so that they are optically shaded from evaporation sources. CONSTITUTION:Coils 1, 2 are oppositely provided to the upper and lower outside parts of a vacuum treatment chamber 3 having a shape of rotor with a cruciform section, respectively, and formed into the same polarity by means of excitation, by which cusp-shaped magnetic fields CF are formed. Vacuum arc evaporation sources 5 are provided, respectively, to the close vicinities of the positions where the intensity of the magnetic fields CF is maximal so that the evaporation surfaces of the above evaporation sources 5 are allowed to face the magnetic fields CF, and substrates 6 are disposed, respectively, in the positions in which the magnetic fields CF diverge and which are optically shaded from the evaporation sources 5. When the evaporation sources 5 are ignited in the above constitution and film-forming materials are evaporated, a plasma consisting of the ions of the evaporated materials is allowed to flow efficiently via the magnetic fields CF to the substrates 6 and deposited so as to be formed into films on the substrates 6, respectively. On the other hand, molten grains are not ionized, and are allowed to proceed straight independently of the magnetic fields CF and stopped by the collision with the walls of the treatment chamber 3, and as a result, these molten grains are not deposited on the substrates 6. By this method, the good-quality films free from contamination with the molten grains can be rapidly formed on the substrates 6, respectively.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to the formation of coatings in the fields of wear-resistant coatings for cutting tools, hair rings, gears, etc., electronic components, printed circuits, optics, magnetic devices, etc. This invention relates to improvements in vacuum arc evaporation equipment used.

(Prior art) The vacuum arc evaporation method basically uses an evaporation source (
Coating material particles are generated by arc discharge from the cathode,
This is a method in which this is deposited on a substrate to which a negative bias voltage is applied, and high-energy cathode material atoms are emitted as a plasma beam from the cathode, which is the evaporation source, due to a high arc current, and between the cathode and the substrate. The voltage applied causes acceleration and formation of a film on the substrate. One of the features of this vacuum arc evaporation method is that because the energy of the incident particles is high, a film with high density, strength and durability can be obtained, and it is also attracting attention from a practical standpoint. The main points are that the film formation rate is fast and the productivity is high.

Representative examples of advanced vacuum arc deposition techniques include Japanese Patent Publication No. 58-3033 and Japanese Patent Publication No. 52-146.
There is No. 90. Special Publication No. 58-3033 summarizes [
An arc discharge is generated between the source material and the arc electrode in a vacuum chamber, ejecting a beam of particles consisting of atoms and ions of the source material, at a low voltage of less than 100 volts and a current of about 50 to 300 amperes. The gist of this method is to provide an arc discharge current to impart kinetic energy of about 10 to 100 electron volts to each particle, depositing the particles on the surface of a substrate. In order to increase the directivity, it is disclosed that the anode is formed into a truncated conical tube shape to determine the beam directivity direction, and the beam width is controlled by controlling its aperture degree and diameter expansion angle. It is stated that the use of magnetic fields is effective.

In addition, Japanese Patent Publication No. 52-14690 summarizes [a vacuum metal coating device comprising an evaporation source metal cathode placed on a cooling bed, a trigger electrode for generating a cathode point of discharge on the evaporation surface of the cathode, an exhaust chamber, and an arc electrode]. , the anode is an envelope, the evaporation surface of the cathode faces the inner space of the envelope, and the cathode spot holding device controls the evaporation surface of the cathode, and the cathode spot is moved from the evaporation surface of the cathode to the non-evaporation surface. This structure improves arc stability and cathode material utilization.

(Problems to be Solved by the Invention) Conventional vacuum arc evaporation techniques, including the techniques disclosed in the above-mentioned two patent publications, in addition to plasma particles consisting of ions and neutrons generated from the cathode evaporation surface, Molten particles, i.e., macro particles, macro droplets, etc., which are larger than plasma particles, are generated, and these are mixed into the deposited film on the substrate, causing deterioration of the film surface roughness and reduction of adhesion.
Further, in the case of a reactive coating film, there is a problem to be solved in that molten particles are incorporated into the film without reacting.

As a conventional technique to solve this problem, there is a magnetic field utilizing device shown in Fig. 8, in which a solenoid (C) is bent at right angle between the vacuum arc evaporation source (a) and the substrate (b). They are connected by a pipe (d) maintained in a vacuum, and the plasma generated from the source bends under the action of the magnetic field of the solenoid (C) and travels through the pipe (d) to the substrate (b). However, the molten particles go straight without being affected by the magnetic field and cannot reach the optically shaded substrate (b), making it possible to form a high-quality film that does not contain molten particles. It is said that there is.

However, as shown in the figure, this technique is unsuitable for implementation on an industrial scale because the equipment is large, the available space is limited (implementation and control are difficult, and the effective coating area is small).

Based on the above, the present invention provides that the vacuum arc evaporation apparatus of the prior art cannot avoid mixing of molten particles from the evaporation source into the deposited film in the conventional structure, and that the structure of FIG. 8 requires a large-scale apparatus. Moreover, the purpose is to provide a solution to the problem that the coating area is small and is uneconomical as an industrial device.

(Means for Solving the Problems) In the present invention, the above object is achieved by configuring the vacuum arc evaporation apparatus in a fixed arrangement along the cusp-shaped magnetic field.

As shown in Figure 1, a cusp-shaped magnetic field is a magnetic field in which a pair of magnetic poles with the same magnetism and facing each other are placed on the same axis (X), and for example, coils (1) and (2) are oriented in parallel. By applying currents in opposite directions as shown by the arrows (C), the lines of magnetic force (F) generated between them are distributed in a symmetrical peak-to-peak shape with the imaginary plane (S) at the center of the magnetic pole as the plane of symmetry. It refers to the magnetic field (CF).

In this cusp-shaped magnetic field, when charged plasma particles try to cross the magnetic field lines and go out, a force acts in a direction that prevents them from moving out, so that they are within the internal region (P) shown by hatching in Figure 2. Therefore, the plasma in this part is either at the point (8) where the magnetic field converges around the axis (X) or at the central plane (S) where the magnetic field diverges.
Try to flow out from a position that does not cross the magnetic field.

In the present invention, by utilizing the characteristics of this cusp-shaped magnetic field, specifically, a vacuum arc generation source serving as a plasma supply source is installed at the above-mentioned (8) points (at least one of them) of the cusp-shaped magnetic field, and from there the cusp-shaped magnetic field is By evaporating the deposited material toward the center of the shaped magnetic field and packing the plasma particles into the injection region (P), the plasma will flow out from this region outside the cusp shaped magnetic field under its driving force or potential. By arranging the substrate at the outer periphery of the central plane (S), the outflowing plasma is deposited as a film on the substrate. On the other hand, at the same time, the other party is placed in an optical shadow when viewed from the substrate or vacuum arc evaporation source,
In other words, by interposing an optical shield between the two that blocks visibility, neutral molten particles generated from the vacuum arc evaporation source travel straight without being affected by the magnetic field.
Make it impossible to reach a board located in a position where there is no visibility. As an optical shield that plays such a role, a portion of the vacuum processing chamber may be used, or a shield may be provided in particular.

Further, as the magnetic poles for forming the cusp-shaped magnetic field, permanent magnets may be used in addition to the above-mentioned coils, or a cusp-shaped magnetic field can be similarly formed by using a combination of both.

Combining these concepts, the vacuum arc evaporation apparatus of the present invention has a specific overall configuration in which a film is formed on a substrate surface by vacuum arc evaporation. A pair of magnetic poles are arranged oppositely on the same axis to form a cusp-shaped magnetic field in the space between the two magnetic poles in the vacuum processing chamber, and the magnetic field is focused in a point shape in relation to the cusp-shaped magnetic field, and the magnetic field strength is maximized. A vacuum arc evaporation source for a film-forming substance is arranged near at least one of the positions, with its evaporation surface facing the center of the magnetic field, a substrate is arranged near a position around the center plane where the magnetic field diverges, and the substrate is placed in a vacuum. It is characterized in that the evaporation surface of the arc evaporation source and the optical shielding interposed therebetween occupy a non-see-through position that optically shadows each other.

(Function) According to the present invention, molten particles, which are neutral particles, do not reach the substrate placed in a position optically shaded from the evaporation surface of the vacuum arc evaporation source, and the evaporation particle plasma is caused by the cusp-shaped magnetic field. Since the molten metal is guided by the molten metal and efficiently flows and deposits on the substrate, a high-quality film with less contamination of molten particles can be formed.

Although the apparatus of the present invention can be made more compact than the prior art apparatus shown in FIG. 8, since plasma divergence occurs in a plane, this can be utilized to perform coating deposition on a large number of substrates at the same time. Large area and high processing efficiency.

(Examples) Hereinafter, the present invention will be specifically explained based on examples with reference to FIGS. 3 to 7, and its characteristics will be clarified. FIG. 3 is a longitudinal sectional side view of the first embodiment showing the basic structure of the device of the present invention, FIG. 4 is a lateral plan view thereof, and FIG. 5 is a sectional perspective view schematically showing its operating condition.

In this embodiment, the vacuum processing chamber (3) is a sealable chamber in the shape of a rotating body with a cross-shaped cross section centered on the axis (X), and is evacuated and evacuated by a vacuum pump (4).

On the outside of the upper and lower parts of the vacuum processing chamber (3), the above-mentioned coils (1) and (2) are installed as a pair of magnetic poles facing each other with the same polarity.
are arranged oppositely on the axis (X), and opposite to each other (C)
By applying current and excitation in the directions, the polarity becomes the same in the directions facing each other. By doing so, the cusp-shaped magnetic field (CF) described above is formed. Vacuum processing chamber (
3) By forming the wall with a non-magnetic material, the magnetic field applied inside the vacuum chamber by the external coil can be created without any problem.

Vacuum arc evaporation occurs at or near the position in the vacuum processing chamber (3) that corresponds to the inside of the coils (1) and (2), which is the position where the cusp-shaped magnetic field (CP) is focused into a point and the magnetic field strength is maximum. The source (5) is arranged with its evaporation surface towards the center of the cusp-shaped magnetic field.

Although not shown in the vacuum arc evaporation source (5),
A power source, arc ignition mechanism, arc stabilization mechanism, water cooling mechanism, etc. are attached as necessary.

These can have any structure similar to the above-mentioned special attack. Usually, the vacuum arc evaporation source (5) is provided at both of the two magnetic field focus points of the cusp-shaped magnetic field, but it may be provided only at one of them.

The substrate (6) on which the coating is to be deposited is placed in a vacuum treatment chamber (3).
) and the position where the cusp-shaped magnetic field (CF) diverges, that is, on the central plane of symmetry (S) of this magnetic field, is the axis (
X) is placed at a peripheral position that radially diverges outward. At the same time, this position is such that the substrate (6) is optically in the shadow of the wall of the vacuum processing chamber (3) compared to the vacuum arc evaporation source (5), that is, the position is such that they cannot see through each other. do. That is, in this embodiment, the wall of the vacuum processing chamber (3) serves as an optical shield that blocks visibility. Substrate (6
) is 8 in rotation, and as shown in Figure 4, the number of axis lines (×
) are arranged symmetrically around the points. These boards (6
) may be grounded to the vacuum processing chamber (3), or a negative bias voltage may be applied to the substrate holder (not shown) for attachment.

In such a device configuration, a vacuum arc evaporation source (5)
When the film is ignited to evaporate the material that forms the film, a plasma consisting of electrons and ions of the evaporated material is emitted toward the center of the cusp-shaped magnetic field, as shown by the hatching in Figure 5, and in the process, this plasma is emitted toward the center of the cusp-shaped magnetic field. Under the influence of the magnetic field, the plasma flows out from the location where the cusp-shaped magnetic field diverges without heading toward the wall of the vacuum processing chamber (3), and is efficiently transported to the substrate (6).
It is deposited as a film on the substrate. On the other hand, molten particles are usually not ionized, so even if they are generated in a vacuum arc evaporation source, they will travel straight without being affected by the magnetic field and will collide with the wall of the vacuum processing chamber and be stopped. ) is not deposited.

Further, according to the present invention, since the substrate (6) is placed in a position where the magnetic field is directed and diverged in all directions around the axis (X) at 360 degrees, many substrates can be arranged and processed simultaneously as shown in Fig. 4. With this, a large coating area can be obtained.

FIG. 6 shows a second embodiment of the present invention, and parts equivalent to those in the first embodiment are indicated using the same reference numerals, and redundant explanation will be omitted.

In this embodiment, a permanent magnet (L
A) (2A) are installed with the same poles, for example, N poles facing each other. In addition, instead of using the wall of the vacuum processing chamber (3) as in the previous embodiment as an optical shield, a cylindrical optical shield coaxial with the evaporation source surrounding the vacuum arc evaporation source (5) is placed in front of the evaporation surface of the vacuum arc evaporation source (5). A special shield (7) is provided. This cylindrical body (7) also serves as a shield mechanism, prevents the scattering of molten particles, secures a plasma passage, and also has the role of controlling the plasma flow as an anode for the cathode of the vacuum arc evaporation source (5). It also has a vacuum processing chamber (38).
It is also useful for simplifying the shape as shown in the figure to facilitate manufacturing.

FIG. 7 shows a third embodiment of the present invention, in which parts equivalent to those in the previous embodiment are indicated using the same reference numerals, and redundant explanation will be omitted.

This embodiment makes it possible to process many or large substrates, and the substrates (6) are arranged in a row along the axis (X) in a large vacuum processing chamber (3B), and the vacuum arc evaporation source is (5B), magnetic pole (IB) (2B), optical shielding (7B)
This mechanism is configured to move in the axis (X) direction to carry out vacuum arc deposition.

(Effects of the Invention) As described above, according to the present invention, during vacuum arc deposition,
It is possible to form a high-quality film without contamination with molten particles, and the formation speed is fast, and it can be deposited on a wide coating area or on many substrates at the same time, making mass production and deposition on large substrates possible, making it suitable for industrial use. It is possible to realize various effects such as high operating efficiency of the equipment and low cost of the equipment through efficient production.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the formation of a cusp-shaped magnetic field according to the present invention, FIG. 2 is a cross-sectional view showing the location of plasma within this magnetic field, and FIG. A vertical side view of the first embodiment, FIG. 4 is a cross-sectional plan view thereof,
Figure 5 is a vertical perspective view schematically showing its operating condition;
7 is a longitudinal sectional side view of a second embodiment of the invention, FIG. 7 is a longitudinal sectional side view of a third embodiment of the invention, and FIG. 8 is a longitudinal sectional side view of an example of a conventional vacuum evaporation apparatus. (1) (2)...Coil, (IA) (2A)...
Permanent magnet, (3) (3A) (3B)...vacuum processing chamber,
(4)...Vacuum pump, (5)(5B)...Vacuum arc evaporation source, (6)(6B)...Substrate, (7)(7B)
)...Optical shielding, (X)...Axis, (C)...Current direction, (F)...Magnetic field lines, (CF)...Cusp-shaped magnetic field, (S)...Central plane , (P)...Plasma closed region, (A)...Magnetic field focusing point, (a)...Vacuum arc evaporation source, (b)...Substrate, (C)...Solenoid, (d )...pipeline. Eggplant] Illustration 3

Claims (6)

[Claims] (1) In order to form a film on the substrate surface by vacuum arc evaporation, a pair of magnetic poles facing each other with the same polarity are placed oppositely on the same axis, and a cusp is formed in the space between the two magnetic poles in the vacuum processing chamber. The vacuum arc evaporation source of the film-forming substance is placed near at least one position where the magnetic field is focused into a point in relation to the cusp-shaped magnetic field and the magnetic field strength is maximum, and the evaporation surface is placed at the center of the magnetic field so as to form a shaped magnetic field. The substrate is placed near the central plane where the magnetic field diverges, and the substrate is optically shaded by the evaporation surface of the vacuum arc evaporation source and the optical shielding interposed between them. A vacuum arc evaporation device characterized in that it occupies a non-see-through position. (2) The vacuum arc evaporation apparatus according to claim 1, which comprises a coil in which both the magnetic poles are arranged opposite each other, and currents in opposite directions are passed through both coils. (3) Claim 1, which comprises permanent magnets with both magnetic poles facing each other, with both permanent magnets facing each other with the same polarity side.
Vacuum arc evaporation apparatus described in . (4) The vacuum arc evaporation apparatus according to claim 1, wherein the optical shield comprises a portion of a vacuum processing chamber. (5) The vacuum arc evaporation apparatus according to claim 1, wherein the optical shield comprises a cylindrical shielding member coaxially surrounding the evaporation surface of the vacuum arc evaporation source. (6) The vacuum according to claim 1, wherein the cusp-shaped magnetic field forming device moves in the direction of its axis in the vacuum processing chamber, and the substrates are arranged in a row along that direction. Arc evaporation equipment.