JPH04365856A - Ion plating device - Google Patents

Abstract

PURPOSE:To prevent the adhesion of the vapor deposited matter on the side walls of a crucible in the ion plating device to be used at the time of executing ion plating by an HCD(Hollow Cathode Discharge) method. CONSTITUTION:This ion plating device is installed with an HCD gun 6 so as to aim the emission direction of a plasma beam 9 in the direction parallel with the surface of the evaporating source in a housing part 4 of the crucible 5 and is disposed with a focusing coil 10 for bending the plasma beam 9 and introducing the beam to the evaporating source around the crucible. The aperture of the crucible 5 housing part 4 of such device is formed to a shape having >=1.2 ratio of the long side with respect to the short side and is so designed that the generation of the rotating flow of a melt 3 is obviated even if a magnetic field is impressed by passing a current to the focusing coil 10 around the crucible, by which the adhesion and deposition of the melt 3 onto the side walls of the crucible are averted.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to ion plating, especially HCD (Hollow Cathode D).
The present invention relates to an ion plating apparatus that is advantageously suitable for performing ion plating using the ischarge method.

[0002] Ion plating method using plasma is a method of depositing TiN,
It is often used when applying ceramic coatings such as TiC and Ti(CN). Ion plating methods include HCD method, EB (Electron
Beam) +RF method, multi-arc method, arc discharge method, etc. Among these methods, HCD
This method has a high ionization rate of 20 to 60% and a relatively fast film formation rate of 0.05 to 0.5 μm/min.
It is advantageous when the ceramic coating described above is applied to steel plates having a particularly large surface area. Among these, the HCD method has the advantage of being able to perform ceramic coating easily and smoothly even if conditions such as N2 gas flow rate, degree of vacuum, bias voltage, substrate temperature, and substrate pretreatment change slightly.

0003

[Prior Art] Regarding HCD method ion plating, see, for example, Metal Surface Technology, 35(1) p. 16-24
(1984), Powder and Powder Metallurgy, 32 (1985)
, p. 55-60, respectively.

[0004] In the HCD method, a crucible made of copper, ceramic, or graphite is formed into a cylindrical shape mainly for ease of manufacture, and a hollow cathode for plasma generation (hereinafter referred to as an HCD gun) is used to generate plasma. Usually, the plasma beam is emitted in a straight line from directly above the crucible.

By the way, the biggest disadvantage of the HCD ion plating method is that the HCD gun is made of an expensive material such as Ta, and the beam from the HCD gun uses a large current.
Because the method uses an electron beam that generates a plasma atmosphere with a high ionization rate at low voltage, the HCD gun must be placed directly above the crucible. For this reason, the HCD gun prevents the vapor flow from depositing on the substrate, so there is a problem in that the substrate cannot be uniformly coated.

[0006] In order to solve these problems, the inventors previously published Japanese Patent Application Laid-open Nos. 1-168860 and 1-25276.
In each publication No. 4, an innovative HCD ion plating apparatus was disclosed in which the plasma beam was bent at right angles or obliquely to eliminate obstacles on the evaporation path of the evaporated material toward the substrate. This makes it possible to uniformly form a coating on the substrate, and since the vapor flow no longer attacks the HCD gun, there is no wear and tear on the gun, which also makes it possible to significantly reduce the cost of the HCD gun. .

[0007]

However, when the plasma beam is bent at right angles or obliquely just above the crucible as shown in FIG. Compared to the circular plasma beam ejected in a straight line as shown in the figure, the plasma beam becomes larger in the form of an ellipse. When the beam becomes larger in ellipse shape, the rotation of the melt at the evaporation source becomes larger, and a large amount of melt is deposited on the side wall of the crucible housing, where the centrifugal force of the melt becomes large, resulting in a long beam. A new problem has emerged in that it is no longer possible to produce time-stable coatings.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to advantageously solve the above-mentioned problems and provide a large-capacity HCD method ion plating apparatus that can realize stable ceramic coating over a long period of time.

[0009]

[Means for Solving the Problems] The inventors have discovered that in order to realize a ceramic coating that is stable for a long period of time, it is necessary to use a beam bent at right angles or diagonally to form a large ellipse. It is important to suppress the rotation of the crucible, and we have found that it is effective to add some innovation to the shape of the crucible. That is, the present invention provides an HCD method ion plating apparatus in which a crucible in which a storage part for an evaporation source is formed, a hollow cathode for plasma generation corresponding to the crucible, a substrate, and a reaction gas inlet are arranged in a vacuum chamber. , the hollow cathode is installed with the plasma beam emitting direction set in the horizontal direction parallel to the evaporation source surface in the housing part of the crucible, and a focusing coil is arranged around the crucible to bend the plasma beam and guide it to the evaporation source. , a focusing coil is arranged around the vapor transfer path from the crucible to the immediate vicinity of the substrate, and the crucible storage section has a rectangular opening with a ratio of the long side to the short side of 1.2 or more facing the substrate. This is an ion plating apparatus characterized by comprising:

[0010] Furthermore, it is possible to provide a protective cover on the focusing coil disposed around the vapor movement path, and further to provide the focusing coil on the side of the substrate opposite to the vapor movement path.
It is advantageous in implementation.

[0011]

[Operation] When installing an HCD gun that is an obstacle on the evaporation movement path toward the substrate, it is necessary to guide the plasma beam from the HCD gun to a crucible that is bent at right angles or diagonals. A focusing coil placed around the crucible is essential for this purpose.

The magnetic field formed by this focusing coil serves to guide the plasma beam, but on the other hand also affects the evaporation source within the crucible, especially in the conventional case with a circularly opened receptacle 1 as shown in FIG. In the crucible 2, a centrifugal force acts on a molten evaporation source (for example, molten Ti: hereinafter referred to as molten material) 3, giving rotation to the molten material. That is, since a mechanism for generating a magnetic field using the focusing coil 10 is adopted, rotation occurs in the melt 3 as shown by the arrow in FIG. 2. The melt 3 then gradually accumulates on the side walls of the crucible surrounding the housing 1 and changes the current in the focusing coil around the crucible, making it impossible to maintain a stable coating for a long time.

On the other hand, in the conventional crucible 2 having the rectangular opening storage portion 1 according to the present invention, even when a current is applied to the focusing coil around the crucible and a magnetic field is applied, the crucible with the circular opening remains as shown in FIG. A rotating flow of the melt 3 as seen in the above does not occur. This is because the rectangular shape prevents the melt 3 from rotating against the side walls of the crucible. In other words, since the melt 3 has a certain degree of toughness, the rotational flow is easily inhibited by external obstacles such as the side walls of the crucible, so that rotation is prevented. Therefore, the melt 3 does not adhere or accumulate on the side wall of the crucible, and even if the focusing coil is used for a long time, a magnetic field can be applied under constant conditions, so it is possible to perform stable coating. . Here, with respect to the opening shape of the storage part of the crucible, rotation of the melt can be suppressed if the ratio b/a of the long side b to the short side a is 1.2 or more. That is, if the ratio of the opening of the storage section is less than 1.2, the opening of the storage section will be square, and there will be no obstruction caused by the side walls. On the other hand, if the upper limit of the ratio is 10 or more, the manufacturing cost will increase, so it is desirable to set the upper limit to 10.0 or less.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 4 shows the structure of an ion plating apparatus according to the present invention. 6 in the figure is an HCD gun, which is equipped with a Ta cathode 6a and a graphite cover 6b, and by adopting such a double structure, abnormal discharge of the plasma beam inside the gun is minimized. This H.C.D.
The gun 6 is installed in a horizontal direction parallel to the melt 3 in the storage part 4 of the crucible 5, and around it is a focusing coil 8 with an anti-fouling cover 7, which directs the generated plasma beam 9 in the horizontal direction. eject. This beam 9 is bent at right angles by a focusing coil 10 with an anti-fouling cover 7 arranged around the crucible 5 to melt and ionize the substance in the crucible 5 . As details of the crucible 5 are shown in FIG. 3, the opening of the storage section 4 has a long side to short side ratio of 1.2.
It is important to have the above rectangular shape.

Further, reference numeral 11 denotes a focusing coil with an anti-fouling cover 7 surrounding the vapor transfer path up to the substrate 12, and 13 a focusing coil installed on the opposite side of the vapor transfer path of the substrate 12. Useful for improving vapor deposition efficiency. Furthermore, 14 is a reaction gas inlet, 15
is an exhaust port and 16 is a chamber. The anti-adhesion cover 7 that covers each focusing coil is designed to prevent deposits from adhering to the focusing coils 8 and 10, which are used to control the trajectory of the beam, for example, and thereby changing the current in the coils and changing the magnetic field applied to the focusing coils. Therefore, it protects the focusing coil so that the beam trajectory does not go awry, contributing to the realization of stable coating over a long period of time.

Next, the coating process using the ion plating apparatus shown in FIG. 4 will be specifically described. (Coating treatment example 1) C: 0.071%, Si:
3.46%, Mn: 0.086%, Al: 0.026
%, Se: 0.025%, Cu: 0.20% and M
o:0.022% silicon steel slab containing 13%
After heating at 80° C. for 4 hours, it was hot rolled to obtain a 2.0 mm thick hot rolled sheet. Thereafter, cold rolling was performed twice with intermediate annealing at 1100° C. to obtain a final cold rolled sheet having a thickness of 0.23 m. Next, after performing primary recrystallization annealing to decarburize in hot water at 840 °C, annealing was performed at 110 °C at 10 °C/h from 850 °C.
After raising the temperature to 0°C to develop Goss-oriented secondary recrystallized grains, purification annealing was performed in dry H2 at 1230°C. Thereafter, oxides on the surface of the steel plate were removed, and the surface was electrolytically polished to a center line average roughness of 0.07 μm.

[0017] Using the ion plating apparatus shown in FIG. 4, electric current was applied to the surface of the steel plate thus obtained:
1500A, voltage: 70V HCD gun operating condition T
An iN film was deposited to a thickness of approximately 1 μm. In addition, the opening shape of the crucible storage part in the ion plating device is b/
A rectangle with a=2.0 was used. When a film formation experiment according to the above was carried out for 20 hours, stable film formation was achieved with no change in voltage or current during coating, and no Ti was deposited on the side walls of the crucible.

(Coating treatment example 2) C: 0.043
%, Mn: 0.35%, P: 0.003%, S: 0
．． Using the ion plating apparatus shown in FIG. 4, a CrN film (1
．． The coating process was carried out for 20 hours. Note that the opening shape of the crucible housing in the ion plating apparatus was a rectangle with b/a=2.5. This coating process was carried out with the operating conditions of the HCD gun set at 1500 A and 70 V, and even after 20 hours, the conditions were 1500 A and 69.5 V, the same as the initial conditions, and extremely stable coating could be achieved. Of course, there is no accumulation of Cr on the side wall of the crucible after treatment.

[0019]

As described above, by using the ion plating apparatus according to the present invention, it is possible to maintain an extremely stable ceramic coating for a long period of time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the locus of a plasma beam from an HCD gun and the planar shape of its irradiation part.

FIG. 2 is a schematic diagram showing a conventional crucible.

FIG. 3 is a schematic diagram showing a crucible according to the invention.

FIG. 4 is a schematic diagram of an ion plating apparatus according to the present invention.

[Explanation of symbols]

1 Storage part 2 Crucible 3 Melt 4 Storage section 5 Crucible 6 HCD gun 6a Ta cathode 6b Graphite cover 7 Anti-fouling cover 8 Focusing coil 9 Blasma beam 10 Focusing coil 11 Steam movement path 12 Substrate 13 Focusing coil 14 Reactant gas inlet 15 Exhaust port 16 Chamber

Claims (2)

[Claims] Claim 1: A crucible in which a storage part for an evaporation source is formed, a hollow cathode for plasma generation, a substrate, and a reaction gas inlet corresponding to the crucible are arranged in a vacuum chamber.
In the CD method ion plating apparatus, the hollow cathode is installed with the plasma beam emitting direction set in the horizontal direction parallel to the evaporation source surface in the storage part of the crucible, and a focusing coil is installed to bend the plasma beam and guide it to the evaporation source. A focusing coil is placed around the crucible, and a focusing coil is placed around the vapor transfer path from the crucible to the immediate vicinity of the substrate, and the crucible housing is rectangular with a ratio of the long side to the short side of 1.2 or more. An ion plating device characterized in that an opening of the ion plating device is directed toward a substrate. [Claim 2] Claim 1, wherein a protective cover is provided on the focusing coil arranged around the vapor movement path, and the focusing coil is further provided on the side of the substrate opposite to the vapor movement path.
The ion plating device described in .