JPH02274872A - Evaporator for ion plating - Google Patents

Abstract

PURPOSE:To form a film deposited by evaporation at large amounts which is excellent in adhesive property by arranging a focusing coil for surrounding a vapor transfer route reaching a substrate from a crucible and arranging a focusing coil having small diameter around the outside layer of a hollow cathode and also providing a magnet to the undeposited surface side of the substrate. CONSTITUTION:In a vapor deposition device for ion plating, a focusing coil 8 is provided which surrounds a vapor transfer route reaching a substrate 1 from a crucible 3. A focusing coil 10 having diameter not larger than 1/2 of diameter of the abovementioned focusing coil 8 is arranged around the outside layer 7 to 1 of an HCD gun 4 utilized as a hollow cathode. The influencing force of a magnetic field exerted from an inclination is made smaller than a magnetic field exerted on the vapor transfer route. The injection direction of plasma beams 9 is decided for the surface of an evaporation source in the crucible 3. Furthermore, a coil or a magnet 11 which generates the lines of magnetic force parallel to the surface deposited by evaporation is provided to the undeposited surface of the substrate 1. The material deposited by evaporation is uniformly stuck.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an ion plating apparatus, particularly a so-called H CD (Hollow Cathode Dis).
The present invention relates to an ion plating evaporator that enables the formation of a deposited film with particularly excellent uniformity and adhesion at high deposition efficiency when performing ion plating using the charge method.

(Prior art) The ion plating method using the HCD method has an extremely high ionization rate, so it cannot be used with ordinary EB (electron beam).
The quality of the deposited film is better than that of ion plating.
In addition to having excellent adhesion to the substrate, the HCD method allows for easy and smooth adaptation even if conditions such as reaction gas flow rate, degree of vacuum, bias voltage, substrate temperature, and substrate pretreatment change slightly. It is also known that there are great advantages even where

In other words, regarding ion plating using the HCD method, Metal Surface Technology 35 (1) P, 16-24 (1
984), Powder and Powder Metallurgy 32 (1985) P
, 55-60.

(Problem to be solved by the invention) Currently used hollow cathodes for plasma generation, namely H
The material of the CD gun is Ta, and its actual durability life is about 100 to 150 hr, and it cannot be used for coating beyond this length, so it is very expensive (-4 liters per liter).
0 to 1 million yen), which accounts for about 30 to 50% of the coating cost, so there is a desire to develop an inexpensive HCD gun that can be used stably for a long time.

In the current ion plating method using the HCD method, a Ta HCD gun that is bent into an inverted shape is mainly used to facilitate the initial HCD beam start and to facilitate the dissolution of evaporated substances such as TI. . For this reason, when performing a TiN ceramic coating on a substrate, not only does the coating film become thin directly above the HCD gun, but also the HCD gun with this shape has the disadvantage of being impinged by the high-temperature Ti vapor flow. It also had the disadvantage of making you thinner.

Recently, the inventors have developed a graphite HCD gun to replace the conventional Ta HCD gun in order to reduce the cost of the HCD gun. However, this graphite HCD gun has a manufacturing cost of 1/20 to 1/2 compared to that of conventional Ta.
100, but it has been found that it is not necessarily optimal for the discharge characteristics required of an HCD gun, especially the requirement that it be able to be used stably for a long time.

Therefore, the outer layer is graphite and the inner layer is Ta.

We have studied a concentric double layer HCD gun using W or LaBb, and found that although it is inexpensive, it has good discharge characteristics and can be used stably for a long time, making it revolutionary as an HCD gun. It turns out. However, since such a double-layer HCD gun has an excessively large outer diameter, the coating film on the substrate portion directly above the HCD gun tends to become thinner. When using the HCD gun, uneven heat transfer to the substrate due to the red heat of the gun occurred directly above the HCD gun, and a solution was needed.

In addition, the capacity of conventional HCD guns is 30OA or 50OA.
For example, the film formation rate in a commonly used ion plating device for OA is 0.05 to 0.5μ for Ti coating.
If/1llIn, and the ionization rate at this time was about 30 to 40% at most, but in recent years, in order to increase the film formation rate to about several μII/m1n,
The development of HCD guns for evaporation with a large capacity of about 000λ has progressed, and increasing the capacity of the HCD gun in this way has the advantage that the ionization rate increases to 50% or more and the film quality by ion plating can be greatly improved.

However, when such a large-capacity HCD gun is used, not only the cost of the cathode gun mentioned above increases, but also the non-uniformity of the coating film and the non-uniformity of heat to the substrate as the diameter of the HCD gun increases. The problem of peeling off of the deposited film due to this problem is extremely important. That is, when using a large-capacity HcD gun, it is required to increase the adhesion efficiency and maintain a favorable plasma atmosphere.

Therefore, it is an object of the present invention to provide an ion plating evaporator that eliminates the various drawbacks mentioned above and performs mass deposition using a large-capacity HCD gun of about 1000 A or more.

(Means for Solving the Problems) The above objectives are advantageously satisfied by a configuration having the following points as its main points.

That is, the present invention provides HCD method ion plating in which a plurality of crucibles containing evaporation sources, a plurality of hollow cathodes for plasma generation corresponding to the crucibles, a substrate, and a reaction gas inlet are arranged in a vacuum chamber. In the apparatus, a focusing coil surrounding all the focusing coils and a vapor transfer path from the crucible to the immediate vicinity of the substrate is installed outside the focusing coil surrounding the crucible, and a hollow cathode consisting of Ta, W and L a B b is installed. an inner layer consisting of at least one member selected from the group consisting of an outer layer of graphite covering the outer periphery of the inner layer; and an outer periphery of the outer layer surrounded by a diameter not more than 1/2 of the diameter of the focusing coil surrounding the vapor transfer path. A focusing coil is installed with the plasma beam emitting direction horizontally or obliquely downward relative to the surface of the evaporation source in the crucible, and a magnet or coil that generates magnetic lines of force parallel to the evaporation surface of the substrate is attached to the substrate. This is an ion plating evaporation device that is installed at a position facing a crucible with a crucible in between.

Further, the present invention provides the above device in which the hollow cathode is made of Ta.
, W and L a B b; This device consists of a buried ceramic layer.

Furthermore, in implementation, it is advantageous to cover the focusing coil surrounding the outer periphery of the outer layer of the hollow cathode with ceramics, and to further fix the cylindrical ceramic in which the focusing coil is embedded integrally with the outer layer with a certain gap. It is.

(Function) Now, FIG. 1 schematically shows a batch type HCD method ion plating apparatus using the ion plating evaporator of the present invention, where 1 is a substrate, 2.2'
is the reaction gas inlet, 3.3' is the crucible, 4.4' is the evaporation source (for example, TL), 5°5' is the exhaust port for high vacuum drawing,
6 is a vacuum chamber, 7° 7' is an HCD gun, 8.8' is a focusing coil surrounding the vapor transfer path from crucibles 3, 3' to substrate 1, and 9.9' is a plasma beam.

The HCD gun 7.7' has an outer layer of graphite 71.7'
-1 and an inner layer 7-2°7'-2 of Ta in this example are integrally combined. Although not shown in order to prevent electric discharge, the inner layer 7-2 or 7゛2 and the evaporation source 4 or 4 in the crucible
' and can be energized. This allows this H
Abnormal discharge of the CD gun is reduced, and the life of the gun is extended.

Further, by keeping the distance between the HCD gun 7 and the crucible 3 or 3' constant using the feeding mechanism 7-3 or 7'3, stable plasma beam supply can be ensured for a long period of time. In the figure, 7-4.7'-4 is the power supply for the HCD gun, and 7-5
．． 7'-5 indicates an Ar gas supply port, and 10 or 10' is a focusing coil around the outer layer 7-1 or 7'-1.

This focusing coil 10.10' focuses the generated plasma into a narrow plasma beam 9.9', and the diameter of the focusing coil 10.10' is 172 or less than the diameter of the focusing coil 8.8' in the vapor transfer path. It is important to make the influence of the oblique magnetic field smaller than the magnetic field on the vapor movement path. This is based on the following findings.

In other words, according to the inventors' experiments, if a large-capacity HCD gun is used and a coil is provided to focus the plasma beam on the hollow cathode, a large amount of the evaporation source can be dissolved and the amount of evaporation can be increased, but the amount of evaporation is It was found that a suitable amount of adhesion to the substrate could not be obtained, and that the cause of this was that the magnetic field created by the focusing coil around the hollow cathode was disturbing the magnetic field created by the focusing coil surrounding the vapor flow toward the substrate. did. Therefore, we searched for conditions for focusing the plasma beam without disturbing the vapor flow, and found that the diameter of the focusing coil on the outer periphery of the hollow cathode should be limited to 172 mm or less of the diameter of the focusing coil on the vapor transfer path.

Next, the plasma beam 9゜9' focused into a thin beam is applied with a magnetic field from top to bottom by a focusing coil 8゜8' around the crucible 3.3', and the molten material is heated as shown by the dotted line in the figure. It is then bent towards the direction and subjected to irradiation. The plasma beam irradiated in this manner evaporates the evaporation source directly upward, making it possible to provide uniform evaporation on the substrate.

Furthermore, a coil (or magnet) 11 that generates magnetic lines of force parallel to the vapor deposition surface is installed on the non-evaporation surface side of the substrate 1 to uniformly adhere the evaporated material.

Further, the inner layer 7-2 (or 7'2) of HCD gamma may have the structure shown in FIG.

That is, the inner layer of the HCD gun 7 shown in the same figure has a head 14 made of a thin-walled tube made of W and welded to a base 13 made of a thick-walled tube made of Ta and fixed to the chuck 12 by welding or the like. Furthermore, a fin 15 made of Ta and having a ten-shaped cross section and extending coaxially with the head 14 is welded to the inner wall surface of the head 14. Note that 16 is a welded part, 17 is an opening, and 18 is, for example, an Ar
Indicates a gas inlet such as.

In the HCD gun having the above configuration, the head 14 made of W is arranged in the region where plasma is mainly generated, that is, the high temperature region, and the base 13 made of Ta is arranged in the region where less plasma is generated, that is, the low temperature region. It is characterized by

Further, as shown in FIGS. 3(a) and (b), the outer layer 7
-1 (or?'-1) focusing coil 10 (1
0") is preferably covered with ceramics 19 to form an insulated coil to prevent discharge between the outer layer 7-1 and the focusing coil 10. In this case, the outer layer 7-1 is covered with ceramics 19.
9, the outer layer 7-1 may be omitted since it protects the cathode 7-2 against attack from the outer vapor flow.
At this time, if the focusing coil 10 is embedded in the cylindrical ceramic 19 and the ceramic 19 is fixed integrally with the outer layer 7-1, the gap between the ceramic 19 and the outer layer 7-1 can be kept constant and stable. It can be used for a long time. Note that (C) in the same figure is an example in which the hollow cathode is a rectangular parallelepiped.

Although a batch type ion plating apparatus is shown as an application example of the apparatus of this invention, it is also effective in a large continuous type ion plating apparatus, and in this case, the substrate, that is, the steel plate to be ion plated, is Air-to-air passes through a series of differential pressure chambers whose degree of vacuum is successively increased on the inlet side leading to the cooling area, and passes through a series of differential pressure chambers whose degree of vacuum is successively decreased on the outlet side
This can be easily realized by a differential pressure sealing method that induces continuous passage of the elongated material while maintaining the pressure difference between the differential pressure chambers.

(Example) C0,041wt% (hereinafter simply referred to as %), St 3
．． 31%, MnO, 073%, Mo 0.011%,
2. Hot-rolling a silicon steel slab containing 0.021% Se, 0.025% SbO, and the remainder being essentially Fe.
□After making the thickness am, 2
The sample was cold-rolled twice to obtain a final cold-rolled sheet with a thickness of 0.20 mm.

After that, after decarburization and primary recrystallization annealing in wet hydrogen at 820"C, MgO (35%) and Al
t's (60%), Ti0t (3%) and Mg5O4 (
After applying a slurry of an annealing separator mainly composed of
Purification was carried out at C for 5 hours in dry H2.

Next, the oxides on the surface of the steel plate were removed by pickling treatment, and then the steel plate was electrolytically polished to a mirror surface with a center line average roughness of 0.05 μm.

Thereafter, a TiN film having a thickness of 1 μm was formed using the ion plating apparatus of the present invention shown in FIG.

The plasma generation conditions at this time were an acceleration voltage of 70V and a current of 1
As 000A, the focusing coil 10, 1 around the HCD gun
The excitation conditions for the focusing coils 8 and 8' around the crucible and the coil 11 on the non-evaporated surface side of the substrate were as shown in Table 1, respectively. In the second case, the bias voltage was 50V and the substrate temperature was 400°C. The magnetic properties and adhesion of the product thus obtained are also summarized in Table 1.

As is clear from Table 1, under the conditions according to the present invention, both the uniformity and adhesion of the coating were excellent.

(Effects of the Invention) According to the present invention, it is possible to form a deposited film in large quantities with good uniformity and excellent adhesion with high efficiency by HCD ion plating.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the ion plating apparatus of the present invention, FIG. 2 is a sectional view of a hollow cathode, FIG. 3(a) is a sectional view of a hollow cathode, FIG.
C) is an end view of the hollow cathode. ■... Substrate 3... Crucible 4... Evaporation source 6... Vacuum chamber 77'... HCD gun 7-1.7'-1... Outer layer 7-2.7' - 2... Inner layer 7-3.7' -3... Feeding mechanism 7-4.7' -4... HCD gun power supply 7 5.7
'5-Ar gas supply port 8.8'...Focusing coil 9.9'...Plasma beam 10, 10'...Focusing coil 11...Coil 12
... Chuck 13 ... Base 14 ... Head 15 ... Fin 16 ... Welding part 17 ... Opening 18 ...
...Gas inlet 19...Ceramics patent applicant Kawasaki Steel Corporation

Claims (1)

[Claims] 1. An HCD in which a plurality of crucibles containing evaporation sources, a plurality of hollow cathodes for plasma generation corresponding to the crucibles, a substrate, and a reaction gas inlet are arranged in a vacuum chamber.
In the method ion plating apparatus, all the focusing coils and the focusing coil surrounding the vapor transfer path from the crucible to the immediate vicinity of the substrate are installed outside the focusing coil surrounding the crucible, and the hollow cathode is made of Ta, W and LaB_6. an inner layer made of at least one material selected from the group consisting of; an outer layer of graphite covering the outer periphery of the inner layer; and an outer periphery of the outer layer having a diameter not more than 1/2 of the diameter of the focusing coil surrounding the vapor transfer path. A focusing coil surrounding the substrate is installed with the plasma beam emitting direction horizontally or diagonally downward relative to the surface of the evaporation source in the crucible, and a magnet or coil that generates magnetic lines of force parallel to the evaporation surface of the substrate is installed as a sub-concentration coil. An ion plating evaporation device located opposite the crucible that holds the straight. 2. The ion plating evaporation device according to claim 1, wherein the focusing coil surrounding the outer periphery of the hollow cathode is coated with ceramics. 3. The ion plating evaporation device according to claim 2, wherein the cylindrical ceramic in which the focusing coil is embedded is fixed integrally with the outer layer with a predetermined gap. 4. In the ion plating evaporator according to claim 1, the hollow cathode is provided with an inner layer made of at least one member selected from the group consisting of Ta, W and LaB_6, and a vapor transfer path covering the outer periphery of the inner layer. An ion plating evaporator comprising a ceramic layer embedded with a focusing coil surrounded by a diameter of 1/2 or less of the diameter of the surrounding focusing coil.