JPH0548302B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for forming a thin film on the surface of a complex-shaped base material by ion plating. [Prior Art and Problems] For example, in structural materials made of various metals, ceramics, etc., various metal thin films are formed for the purpose of hardening the surface of the base material or imparting gloss. ing. When forming a film on such a base material, the following film thickness control method has conventionally been adopted. Film thickness sensor method: The material to be deposited in a crucible placed in a vacuum chamber is irradiated with an electron beam, etc. to evaporate it, the amount of evaporation is detected by a film thickness sensor, and the output of the electron beam is adjusted to deposit the material into the chamber. A uniform thin film is formed over the entire placed substrate. By rotating or revolving the base material holder placed above the crucible placed in the vacuum chamber, the difference in the amount of vapor deposition between the center and peripheral parts of the base material is reduced and a uniform thin film is formed over the entire base material. Form. However, although the film thickness sensor method and the base material rotation method described above can control the overall average film thickness, it is not possible to control the film thickness at any arbitrary location. For this reason, it becomes difficult to form a thin film with a uniform thickness on the surface of a complex-shaped base material. For this reason, the hollow cathode method, the reactive ion plating method, and the plasma gun method are known as methods for forming a thin film on the surface of a complex-shaped base material. However, each method has the following problems. In the hollow cathode method, since the negative voltage at the discharge part is high, holes are opened, and in U-shaped substrates, the substrate voltage is lowered to a predetermined 70°C due to the hollow cathode phenomenon.
%, so even if a film could be formed, the adhesion force would be very low. However, with such a method, it is not possible to make the film thickness uniform, and it is not possible to perform partial film thickness control. In the reactive ion plating method, since the ionization electrode (+) is located at the bottom, the substrate voltage is significantly lowered due to the hollow cathode phenomenon in the case of a hole being opened or a U-shaped substrate. Also, the film quality is not good. In the plasma gun method, since the vacuum chamber pressure can be lower than that of the plasma gun, it is possible to suppress a drop in the substrate voltage due to the holocathode phenomenon, but since the plasma is formed in a fixed lateral direction within the chamber, The holes and U-shaped parts create shadows, preventing plasma from being introduced deep inside.
A film can only be formed on a base material in which the holes and the like are shallow. The present invention has been made to solve the above-mentioned conventional problems, and is capable of uniformly forming a thin film on the surface of a base material having holes or having a complicated shape such as a U-shape. This is the method we are trying to provide. [Means for Solving the Problems] The present invention includes a vacuum chamber, a substrate holder rotatably disposed within the chamber, a deposition source disposed near the bottom of the chamber, and a vacuum chamber provided in the chamber. an air-core magnet provided on the outside of the chamber corresponding to the outer periphery of the plasma gun and on the outside of the chamber facing the plasma gun for focusing the plasma drawn into the chamber; , a rocking motion, a vertical motion, and a horizontal direction arranged concentrically with respect to the center of the chamber to focus the plasma drawn into the chamber from the plasma gun at high density onto the surface of the base material held by the holder. ionizing and evaporating vaporized gas from the evaporation source onto the surface of a complex-shaped base material held in the holder by an ion plating device equipped with a plurality of opposing electrodes that can be moved to and have a built-in magnet; In the method of forming a film, the positions and orientations of the plurality of counter electrodes are held in the holder, synchronized with the rotation of the base material so as to follow the surface shape of the rotated base material, and the plasma density and shape around the base material are adjusted. This is a method of forming a thin film by ion plating, which is characterized by controlling. [Function] According to the present invention, the positions and orientations of a plurality of opposing electrodes containing built-in magnets are held in a holder, and a hole to be rotated is opened or a hole is formed to follow the surface shape of a base material having a complicated shape such as a U-shape. By synchronizing the rotation of the base material and controlling the density and shape of the plasma drawn from the plasma gun into the vacuum chamber around the base material, the evaporated material from the evaporation source is transferred to the base material. Since the film can be formed on the surface of the complex-shaped base material, a thin film can be uniformly formed on the complex-shaped base material surface. [Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view showing the ion plating apparatus used in this example, and FIG. 2 is a schematic cross-sectional view of FIG. 1. Reference numeral 1 in the figure indicates a vacuum chamber, and an exhaust pipe 2 is provided on the lower side wall of the chamber 1 and communicates with a vacuum pump (not shown) for maintaining the chamber 1 at a predetermined degree of vacuum. Moreover, 3 in the figure is a vapor deposition source. The vapor deposition source 3 includes a crucible 4 installed at the bottom of the chamber 1, an electron gun 5 installed on the lower side wall of the chamber 1 for irradiating the crucible 4 with an electron beam, and an electron gun 5 located above the crucible 4. a deflection coil 6 disposed nearby for deflecting the electron beam from the electron gun 5 and irradiating the vapor deposition material in the crucible 4;
It is composed of. Further, a plasma gun 7 as a plasma generation source is provided on the outer wall of the chamber 1,
The rear part of the plasma gun 7 is provided with an introduction pipe (not shown) for introducing a predetermined gas 8 such as nitrogen (N ₂ ). Note that a plasma constriction section 9 is provided on the side wall of the chamber 1 in which the plasma gun 7 is provided. In addition, near the connection of the plasma gun 7 with the chamber 1 and on the outer wall portion of the chamber 1 facing the plasma gun 7, air-core magnets 10a and 10b are provided to prevent the plasma drawn from the plasma gun 7 from diffusing. are provided for each. On the side wall of the chamber 1, which is located almost on the same plane as the installation location of the plasma gun 3, five disc-shaped counter electrodes 12 ₁ to 12 ₅ each having a built-in electromagnet 11 are arranged to swing, move vertically, and move horizontally. It is set up so that it can be moved.
The positions and orientations of these counter electrodes 12 ₁ to 12 ₅ are held in a holder (to be described later) by a controller (not shown), and are synchronized with the rotation of the base material so as to follow the surface shape of the rotated base material. It is designed to be driven. The electromagnets 11 built into each of the opposing electrodes 12 ₁ to 12 ₅ are configured to generate magnetic force by a power source (not shown). Further, a holder 13 for holding a base material is disposed near the plasma generation region within the chamber 1, and the holder 13 is supported and suspended by a rotating shaft 14. The holder 13 is connected to the variable power source 15 so that a negative voltage is applied thereto. Example First, SUS304 with the complicated shape shown in Figure 3
A base material 16 made of This base material 16 has a structure in which flat plate parts 18a and 18b are attached to the left and right sides of a central ring part 17, and the back surface of a U-shaped block part 19 is joined to the lower surface of one of the flat plate parts 18b. . Note that the flat plate portions 18a, 18b
The width is 28 mm, the length is 100 mm, and the block part 19
The height is 50mm and the width is 30mm. Subsequently, the complex-shaped base material 16 was held in the holder 13 in the vacuum chamber 1, and the titanium chip 20 was housed in the crucible 4. Next, a vacuum pump (not shown) was operated to exhaust the gas in the chamber 1 through the exhaust pipe 2. Next, the base material 16 held by the holder 3 is rotated by the rotating shaft 14 at 11 rpm, and while a negative voltage is applied to the base material 16 from the variable power source 15, an electron beam is emitted from the electron gun 5. The titanium chip 20 housed in the crucible 4 was irradiated with the electron beam by the deflection coil 6 to melt and evaporate it. At the same time, plasma generating gas is supplied to the plasma gun 7.
By supplying N ₂ , plasma 21 is generated in the vacuum chamber 1 from the plasma gun 7, and the positions of the five disc-shaped counter electrodes 12 ₁ to 12 ₅ are controlled by a controller (not shown). It was driven in synchronization with the rotation of the base material 16 so that the orientation followed the surface shape of the base material 16 being held and rotated by the holder 13. That is, among the disc-shaped counter electrodes 12 ₁ to 12 ₅ , the counter electrode to which the flat plate portion 18a of the base material 16 approaches is moved downward while being swung while keeping its electrode surface vertical. and base material 16
rotational movement (movement to another adjacent counter electrode)
It was moved horizontally in synchronization with the On the other hand, among the disc-shaped counter electrodes 12 ₁ to 12 ₅ , the base material 16
In the counter electrode where the U-shaped block plate portion 19 of
It was moved upward while being swung while tilted upward by 30°, and moved horizontally in synchronization with the rotational movement of the base material 16 (movement to another adjacent counter electrode). Note that each of the counter electrodes 12 ₁ to 1
Of _2.5 , the magnetic flux density of the counter electrode 12 ₁ facing the plasma gun 7 is set to 50 to 500 Gauss, and the magnetic flux density of the other counter electrodes 12 ₂ to 12 ₅ is set to 100 Gauss to 1k.
Gauss, and the pressure inside the chamber 1 where the plasma 21 is generated was set to 5.0×10 ⁻⁴ torr. The above-mentioned disc-shaped counter electrodes 12 ₁ to 12 ₅ are held in the holder 13 by a controller (not shown), and the base material 16 is adjusted so that their positions and orientations follow the surface shape of the rotated base material 16. By driving in synchronization with the rotation, the plasma 21 drawn into the chamber 1 is focused at high density on the base material 16, and the titanium evaporated from the crucible 4 is ionized by the plasma 21, A thin film was formed on the surface of the base material 16 by reacting with nitrogen ions. Note that if the oscillation and movement amount of the counter electrodes 12 ₁ to 12 ₅ are set by measuring the plasma density around a complex-shaped base material with a sensor before film formation, even a uniform film can have partial film thickness differences. It is also possible to attach it. Reference example When driving each disc-shaped counter electrode 12 ₁ to 12 ₅ ,
A thin film was formed on the complex-shaped base material surface shown in FIG. 3 in the same manner as in the example except that the electrode surfaces were simply kept vertical and oscillated. Therefore, X-ray diffraction and EPMA
When analyzed, it was confirmed that it was TiN. Further, regarding the TiN thin film formed on the base material 16 of the present example and the reference example, when the film thickness of the lower surface A of the flat plate portion 18a shown in FIG. 3 is taken as 100%,
Inner back surface B and side surface C of the U-shaped block plate portion 19
When the film thickness was determined, the results shown in Table 1 below were obtained.

[Table] As is clear from Table 1 above, in this example,
The difference in film thickness between the flat plate portion 18a of the base material 16 and the recessed portion of the block portion 19 can be significantly reduced compared to the reference example,
It can be seen that a uniform TiN thin film can be formed even on a base material with a complex shape. [Effects of the Invention] As detailed above, the present invention provides a method for forming a thin film using ion plating, which can uniformly form a thin film on the surface of a base material having holes or having a complex shape such as a U-shape. Can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing the ion plating apparatus used in the embodiment of the present invention, and FIG.
The diagram is a schematic cross-sectional view, and FIG. 3 is a perspective view showing the base material used in this example. 1... Vacuum chamber, 3... Evaporation source, 4... Crucible, 7... Plasma gun, 11... Electromagnet, 12
₁ to 12 ₅ ... counter electrode, 13 ... holder, 16 ...
... Base material, 18a, 18b ... Flat plate part, 19 ... U-shaped block part, 20 ... Titanium chip, 21 ...
…plasma.

Claims (1)

[Scope of Claims] 1. A vacuum chamber, a base material holder rotatably disposed within the chamber, a deposition source disposed near the bottom of the chamber, and a plasma gun disposed in the chamber; an air-core magnet provided on the outside of the chamber corresponding to the outer periphery of the plasma gun and on the outside of the chamber facing the plasma gun to focus the plasma drawn into the chamber; It is arranged concentrically with respect to the plasma gun and is capable of swinging, vertical movement, and horizontal movement to focus the plasma drawn into the chamber from the plasma gun at high density on the surface of the base material held by the holder. A method of forming a film by ionizing evaporated gas from the evaporation source and evaporating it onto the surface of a complex-shaped base material held by the holder using an ion plating device equipped with a plurality of opposing electrodes containing magnets, The positions and orientations of the plurality of counter electrodes are held in the holder and synchronized with the rotation of the base material so as to follow the surface shape of the rotated base material, thereby controlling the plasma density and shape around the base material. A thin film formation method using ion plating.