JPH03243764A - Sputtering device - Google Patents

Abstract

PURPOSE:To provide the sputtering device which does not generate fluctuations in the magnetic characteristics of the thin films formed on each of substrates of a long sized shape, many of which are held to a rectangular strip shape on a substrate holder by forming the device in such a manner that a part or above of magnetic lines of force are so formed as to be parallel on a target surface. CONSTITUTION:A sputtering gas is introduced into a vacuum chamber 1 evacuated to a vacuum and the inside of the chamber 1 is maintained under 10<-1> to 10<-3> Torr. A voltage is thereafter impressed from a high-frequency power source 8 to a cathode 5 to generate plasma between a substrate electrode 2 and the cathode. The ions in the plasma are sputtered over the entire area of the target 6 by the effect of the magnetic lines of force paralleled on the surface of the target 6 to form the thin film on the substrate 4. The generation of the fluctuations in the magnetic characteristics of the thin films formed on the respective substrates 4 is prevented even if the holding positions and holding directions of the substrates 4 of the long-sized shape, many pieces of which are held in the rectangular strip shape on the substrate holder 4, vary with each of the respective substrates 4 of the long-sized shape.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a sputtering device,
In particular, it is used for manufacturing magnetic heads for magnetic recording media.

(Prior Art) A conventional sputtering apparatus is shown in FIG. 7, in which a substrate holder 3 is attached to the substrate electrode 2 in the upper part of the vacuum chamber 1, and the substrate holder 3 is attached to the substrate electrode 2 shown in FIG. As shown in , a large number of elongated substrates 4 of 2 to 3 as The substrate 4 and the target 6 are opposed to each other with a predetermined interval in the vacuum chamber l. A Helmholtz coil 7 is wound outside the vacuum chamber 1 so as to surround it, and the plasma density, which will be described later, is increased by this Helmholtz coil 7. In FIG. 7, 8 is a high frequency power source or a DC power source connected to the cathode 4, 9 is a gas introduction valve for introducing sputtering gas such as Ar gas, and 10 is a vacuum exhaust port.

Next, a method of forming a magnetic thin film on the surface of a substrate using such an apparatus will be described.

First, after evacuating the inside of the vacuum chamber 1, the gas introduction valve 8 is opened, and a sputtering gas such as gas A is introduced into the vacuum chamber 1.
10-' to I03T inside the vacuum chamber l.

Make it rr.

Thereafter, a voltage is applied to the cathode 5 from a high frequency power source or a DC power source 8 to generate plasma between the substrate electrode 2 and the cathode 5, and the density of the plasma is increased by the Helmholtz coil 7.

Then, the ions in the high-density plasma reach the target 6.
is sputtered, the target particles adhere to the substrate 4, and a thin film is formed thereon. However, at this time, the region of the target 6 to be sputtered corresponds to a high-density plasma, so it is not the entire surface of the target 6 but a local region.

(Problems to be Solved by the Invention) In the conventional sputtering apparatus, as described above, ions in a high-density plasma sputter the target 6, target particles adhere to the substrate 4, and a thin film is formed there. However, since the area of the target 6 to be sputtered corresponds to high-density plasma, it is not the entire surface of the target 6 but a local area. Therefore, more target particles are scattered than in the local area of the target 6 to be sputtered.

However, the substrate holder 3 holds a large number of elongated substrates 4 in the form of strips, and the holding positions and holding directions of the elongated substrates 4 are different for each elongated substrate 4.

Therefore, the target particles scattered from the local area of the target 6 cannot be evenly attached to each elongated substrate 4 under the same conditions such as the incident attachment angle.
A problem occurred in that the magnetic properties of the thin film formed on the elongated substrate 4 differed for each elongated substrate 4, resulting in variations. That is, as shown in FIG.
When a large number of strips are held in the substrate holder 3, the holding positions are not indicated by symbols a-b, and the coercivity, which is one of the magnetic properties of the thin film formed on each long substrate 4, is as shown in FIG. It was different for each holding position as shown in .

An object of the present invention is to provide a sputtering apparatus that solves the conventional problems and does not cause variations in the magnetic properties of the agent film formed on each long substrate held in the form of a plurality of strips on a substrate holder. It is in.

(Means for Solving the Problems) In order to achieve the above object, the first invention makes a substrate and a target attached to a cathode face each other at a predetermined interval in a vacuum chamber, and In a sputtering device that sputter-links a target with ions in generated plasma to form a thin film on a substrate, a pair of magnets are arranged at a distance outside the vacuum chamber so that the target is located between ψ. , characterized in that a magnetic field generated by one of the pair of magnets and a magnetic field generated by the other are repelled, and at least a part of the line of magnetic force of one of the two repelling magnetic fields is made parallel to the line of force on the surface of the target. That is.

Further, in the second invention, a substrate and a target attached to a cathode are opposed to each other at a predetermined interval in a vacuum chamber, and the target is sputtered by ions in plasma generated in the vacuum chamber, thereby sputtering the target onto the substrate. In a sputtering apparatus for forming a thin film, magnets are disposed outside the vacuum chamber on the left and right sides of the target, and at least a part of the lines of magnetic force formed by these magnets are made parallel to the lines of force on the surface of the target. This is a characteristic feature.

(Function) In the sputtering apparatus of the first invention, a pair of magnets are arranged at intervals outside the vacuum chamber so that the target is located in the middle, and a magnetic field generated from one of the pair of magnets,
The magnetic field generated by the other magnetic field is repelled, and at least a part of the lines of magnetic force of one of the two repelling magnetic fields is made parallel to it on the surface of the target, so that the sputtering area of the target covers the entire target area and It is no longer limited to only local areas. Therefore, even if a large number of long substrates are held in the form of strips on a substrate holder, and the holding position and holding direction of the long substrates are different for each long substrate, each long substrate There will be no variation in the magnetic properties of the thin film formed.

Also, in the sputtering apparatus of the second invention, at least a part of the magnetic lines of force formed by the magnets disposed outside the vacuum chamber on the left and right sides of the target are parallel to the lines of force on the surface of the target. A similar effect is achieved, and there is no variation in the magnetic properties of the thin films formed on each elongated substrate.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the first invention, in which a substrate holder 3 is attached to the substrate electrode 2 of the upper part of the vacuum chamber l, and the substrate holder 3 is attached as shown in FIG. A large number of long substrates 4 of 2 to 3 + * m x 30 to 50 mm are held in the form of strips, and a target 6 for forming a magnetic thin film is attached to the cathode 5 at the bottom of the vacuum chamber l. and target 6 are opposed to each other with a predetermined interval in the vacuum chamber l. A pair of electromagnets 11a are provided outside the vacuum chamber l.

11b are arranged vertically at intervals so that the target 6 is located between them, and the magnetic field generated by the upper electromagnet 11a and the magnetic field generated by the lower electromagnet 11b repel, and this repulsive 2 At least a portion of one of the lines of magnetic force of the two magnetic fields is made parallel to the surface of the target 6.

FIG. 3 shows a state in which the magnetic field generated by the upper electromagnet 11a and the magnetic field generated by the lower electromagnet 11b are repelled. In FIG. 1, 8 is a high frequency power source or a DC power source connected to the cathode 4, 9 is a gas introduction valve for introducing sputtering gas such as Ar gas, and 10 is a vacuum exhaust port.

Next, a method for forming a thin film on the surface of a substrate using the above embodiment will be described.

First, after evacuating the inside of the vacuum chamber 1, the gas introduction valve 8 is opened, and a sputtering gas such as Ar gas is introduced into the vacuum chamber 1.
Inside the vacuum chamber l O-'-10-3T.

Make it rr.

Thereafter, a voltage is applied to the cathode 5 from a high frequency power source or a DC power source 8 to generate plasma between the substrate electrode 2 and the cathode 5. At this time, since there are magnetic lines of force parallel to the surface of the target 6, the ions in the plasma are sputtered over the entire area of the target 6 due to the action of these lines of force, forming a thin film on the substrate 4. . In that case, a large number of elongated substrates 4 are held in a rectangular shape by the substrate holder 3, and even if the holding position and holding direction of the elongated substrates 4 are different for each elongated substrate 4, each elongated substrate 4 is There is no variation in the magnetic properties of the thin film formed on the elongated substrate 4. Figure 4 shows the magnetic properties of the thin film formed by the embodiment of the first invention and the magnetic properties of the thin film formed by the conventional apparatus when Cemedust (Fe-Lf-5i-Cr alloy) is used as a target. In this graph, the vertical axis shows coercive force, which is one of the magnetic characteristics, and the horizontal axis shows the distance from the center of the substrate holder to show the holding position of the substrate. 1 from Figure 4
The coercive force, which is one of the magnetic properties, of the thin film formed by the embodiment of the invention is 0.37 to 0.58, which is a variation range that does not pose a practical problem, whereas the thin film formed by the conventional apparatus The coercive force of is high, 0.48 to 1.01,
This value of 1.01 is more than twice that of 0°48, and the range of variation becomes large.

Next, FIG. 5 shows an embodiment of the second invention, in which the same symbols are the same as those in the embodiment of the first invention, but there are differences from the embodiment of the first invention. There are electromagnets 12a and 12 outside the vacuum chamber l on the left and right sides of the target 6, respectively.
This is the point where b is placed.

Therefore, at least a portion of the magnetic lines of force formed by these electromagnets 12a and 12b are parallel to the surface of the target 6, as in the embodiment of the first invention. FIG. 6 shows lines of magnetic force formed by electromagnets 12a and 12b.

Therefore, the method of forming a thin film on the surface of a substrate using the embodiment of the second invention is the same as that of the embodiment of the first invention, and the explanation thereof will be omitted.

Incidentally, although electromagnets are used in the embodiments of the first and second inventions, permanent magnets may be used instead.

(Effects of the Invention) The first invention recited in claim 1 and the second invention recited in claim 2 each have the above configuration, and at least a part of the magnetic lines of force are parallel to the surface of the target. Therefore, the area of the target to be sputtered covers the entire target area, not just local areas of the target.

Therefore, even if a large number of long substrates are held in the form of strips on a substrate holder, and the holding position and holding direction of the long substrates are different for each long substrate, each long substrate There will be no variation in the magnetic properties of the thin film formed. Therefore, the elongated substrate can be held not only at the center of the substrate holder but also at the periphery of the substrate holder, thereby improving production efficiency.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing an embodiment of the m1 invention, and Figure 2 is an explanatory diagram showing an embodiment of the m1 invention.
An explanatory diagram when a large number of elongated substrates are held in the form of strips in a substrate holder used in an embodiment of the invention, FIG. 3 is a perspective view showing lines of magnetic force due to an electromagnet used in an embodiment of the first invention, and FIG. The figure is a graph showing a comparison between the coercive force of the thin film formed by the embodiment of the first invention and the coercive force of the thin film formed by the conventional apparatus. FIG. 5 is an explanatory view showing an embodiment of the second invention, and FIG. 6 is a perspective view showing lines of magnetic force due to an electromagnet used in the embodiment of the second invention. FIG. 7 is an explanatory diagram showing a conventional sputtering apparatus, FIG. 8 is an explanatory diagram when a large number of long substrates are held in the form of strips in a substrate holder used in the conventional sputtering apparatus, and FIG. 9 is an explanatory diagram showing a conventional sputtering apparatus.
The figure is a graph showing the coercivity of a thin film formed on a long substrate using a conventional sputtering apparatus. Figure ψ, l...Vacuum chamber 4...Substrate 5...Cathode 6...Target 11&...Electromagnet 11b...Electromagnet 12a...Electromagnet 12b...Electromagnet In the diagrams, the same reference numerals indicate the same or corresponding parts. Figure 1 Figure 2

Claims (2)

[Claims] 1. A sputtering device in which a substrate and a target attached to a cathode face each other at a predetermined distance in a vacuum chamber, and the target is sputtered with ions in plasma generated in the vacuum chamber to form a thin film on the substrate. , a pair of magnets are arranged at intervals outside the vacuum chamber so that the target is located in the middle, and the magnetic field generated from one of the pair of magnets is repelled by the magnetic field generated from the other. A sputtering apparatus characterized in that at least a part of one of the lines of magnetic force of one of the two magnetic fields is made parallel to the surface of the target. 2. A sputtering device in which a substrate and a target attached to a cathode face each other at a predetermined distance in a vacuum chamber, and the target is sputtered with ions in plasma generated in the vacuum chamber to form a thin film on the substrate. A sputtering apparatus characterized in that magnets are respectively disposed outside the vacuum chamber on the left and right sides of the target, and at least a part of the lines of magnetic force formed by these magnets are made parallel to the lines of force on the surface of the target.