JPS5929112B2 - sputter deposition method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sputter deposition method, and an object of the present invention is to provide a method capable of forming a transparent sputter deposited film with a uniform thickness distribution.

Conventionally, film thickness monitoring during vapor deposition of a vapor-deposited film is performed by, for example, depositing the vapor-deposited film on a crystal resonator and monitoring the change in resonance frequency due to the adhesion of the vapor-deposited film, or by guiding light onto the substrate to which the film is to be deposited. It has been determined from the mutual interference intensity of the light reflected from the substrate surface and the surface of the thin film attached to the substrate. Figure 1 shows the main parts of a conventional sputter deposition apparatus and film thickness monitoring apparatus using mutual optical interference, where 1 indicates a target electrode;
2 is a substrate holder surrounding this target electrode 1;
indicates the sputtering equipment base.

A substrate 3 to be deposited is held on a substrate holder 2. In this case, a light introduction hole 4 is provided in the substrate holder 2, and a light ray 5 is introduced from the outside through the light introduction hole 4 and guided to the surface of the substrate 3. The light reflected from the surface of the substrate 3 is again introduced into the light. If the reflected light is guided outside through the hole 4 and the temporal change in the intensity of the reflected light is observed during deposition, vibration characteristics as shown in Fig. 2 can be obtained, and the period of this vibration can be used to determine the thickness of the deposited film during deposition. can get. In FIG. 2, n indicates the refractive index of light in the deposited film, and λ indicates the wavelength of the introduced light beam. This type of film thickness monitoring device is effective for monitoring the thickness of transparent deposited films, but the thickness distribution of the deposited film becomes large near the introduction hole, making it difficult to form a film with a uniform thickness on the substrate. The disadvantage of this method is that the substrate cannot be placed near the introduction hole, which reduces the number of substrates to be processed. The present invention has been devised to address this problem, and will be described below with reference to drawings showing embodiments.

That is, in the apparatus shown in FIG. 1, the present invention prevents the occurrence of film thickness distribution due to the presence of the light introduction hole 22 of the substrate holder 21 as shown in FIG. This can be prevented by attaching the board holder 21
This is to increase the number of substrates packed into the container.
In this case, a transparent glass plate whose surface is coated with a transparent conductive film can be used as the conductive glass 23. Further, as the light beam 24 passing through the light introduction hole 22, a He-Ne laser is practical. By attaching the conductive glass 23 to the light introduction hole 22 as described above, the characteristics shown in FIG. 4 can be obtained. Diameter 10 in figure 4? The film thickness distribution in the vicinity of the light introduction hole is shown when a light introduction hole with a diameter of 10 mm is provided in a cylindrical substrate holder. This shows the case where conductive glass is inserted and attached to the light introduction hole. It is confirmed that the film thickness distribution near the light introduction hole is completely eliminated by the present invention. The reason why the film thickness distribution decreases is mainly because the disturbance of the electric field near the light introduction hole is reduced by the presence of the conductive glass.
This is thought to be because uniform sputtering discharge is maintained. The sputter deposition method of the present invention is useful for forming magnetic gaps in magnetic heads, such as high-precision magnetic heads for video signals.

A specific example shown in FIGS. 5 to 7 will be described. In FIG. 5, at least one surface 32, 32 of a pair of high permeability magnetic materials 31, 31, such as ferrite, is coated with a thin film of glass made of a low magnetic permeability material, such as borosilicate glass, as shown in FIG. The layers 33, 33 are deposited to a thickness of, for example, 0.3 μm, monitoring the film thickness as described above. In this case, the film thickness accuracy should be 50 to 100 Å or less. These pair of high magnetic permeability magnetic bodies 31, 31 are connected to the glass thin layers 33, 3.
3 and sliced to form a magnetic core having a magnetic gap 34 as shown in FIG.
Usually, a coil 35 is wound around this to form a magnetic head.
In this case, the width of the magnetic gap 34 is approximately equal to the width of the thin glass layer 33.
, 33, and is in the submicron range. Further, since the processing accuracy is required to be 50λ to 100λ or less, the film thickness distribution is also required to be 3% or less. Although conventional techniques are insufficient for mass production that satisfies these precisions, the sputter deposition method of the present invention makes this possible. As explained above, according to the present invention, since conductive transparent glass is inserted into the light introduction hole, disturbances in the electric field near the light introduction hole can be removed, and the film thickness distribution near the light introduction hole can be improved. can.

Therefore, a transparent sputter-deposited film can be formed with extremely high precision and a uniform thickness distribution, and its industrial utility value is extremely large.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is a characteristic diagram of the conventional example, Fig. 3 is a sectional view of main parts showing a basic embodiment of the present invention, and Fig. 4
The figure is a characteristic diagram of the present invention, and FIGS. 5 to 7 are explanatory diagrams showing the manufacturing order of a magnetic head in a specific embodiment of the present invention. 21... Basic holder, 22... Light introduction hole, 23... Conductive glass, 24...
・Light ray, 31... High permeability magnetic material, 32...
...Surface, 33...Glass thin layer, 34...
...magnetic gap.

Claims (1)

[Scope of Claims] 1 In a sputter deposition method using at least a target electrode and a substrate holder surrounding the target electrode and having a substrate disposed on the inner surface, the substrate holder is provided with a light introduction hole, and the light introduction hole is electrically conductive. The light introduced from the light introduction hole during sputter deposition is guided to the surface of the substrate, and the mutual interference intensity of the light reflected from the surface of the substrate and the surface of the thin film attached to this substrate is determined. A sputter deposition method characterized by monitoring the thickness of a sputter deposited film. 2. The sputter deposition method according to claim 1, characterized in that a He-Ne laser is used as the light used to monitor the film thickness. 3. The sputter deposition method according to claim 1, wherein a transparent glass plate whose surface is coated with a transparent conductive film is used as the conductive transparent glass.