JPH01132763A - Magnetron sputtering device - Google Patents

Abstract

PURPOSE:To increase the effective components of the magnetic fluxes penetrating a target so that magnetron action is activated by disposing a superconductive material around a magnet for confinement of charged particles disposed near the target. CONSTITUTION:The superconductive material 13 is disposed around the permanent magnet 6 for confinement of the charged particles disposed near the target 2 consisting of a magnetic material. The magnetic fluxes emitted from the permanent magnet 6 are advanced toward the target 2 by evading the superconductor 13 by the Meissner effect of the superconductor 13 and the direct magnetic flux components are decreased. The parallel magnetic field region of the magnetron is, therefore, widened and the magnetic field intensity is intensified as well. The sputtering rate is thereby improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetron sputtering apparatus for forming magnetic thin films such as magnetic recording media, thin film magnetic heads, and magneto-optical recording media.

2. Description of the Related Art In recent years, sputtering apparatuses have been widely used to form thin films for high-density magnetic recording media, high-density magnetic heads, etc. whose development is rapidly progressing with the advancement of information technology. Examples include magneto-optical disks, perpendicular magnetic recording media, and thin film heads. In magneto-optical disks and perpendicular magnetic recording media, a magnetic thin film made of magnetic transition metals, rare earth metals, or alloys thereof is formed on a plastic substrate or film.

The magnetron sputtering method is known as a film forming method with a relatively low temperature and a high deposition rate, and is suitable for forming a magnetic thin film on the above-mentioned plastic substrate or film. This principle uses so-called magnetron operation, in which charged particles in a static magnetic field receive the Lorentz force and undergo circular motion around the magnetic field. Charged particles are confined in the magnetic field, increasing the efficiency of discharge and generating high-density plasma. It is based on this and suppresses the temperature rise of the substrate by preventing the impact of electrons and the like on the substrate.

The conventional magnetron sputtering apparatus as described above will be explained below with reference to the drawings.

FIG. 2 shows a sectional view of a main part of a conventional magnetron sputtering apparatus. In Fig. 2, 1 is a board;
It can be plastic or glass.

2 is a magnetic target, TeFeCo, Dy
FeCo.

These include CoNi and CoCr. 3 is a target outer peripheral wall, 4 is a shield portion, 6 is an insulating spacer, and 6 is a permanent magnet, which is made of SmCo, NeFeB, or the like.

7 is a yoke, and 8 is a water cooling introduction pipe for cooling the target.

9 indicates a magnetron parallel magnetic field region, and 1o indicates an erosion region eroded by target sputtering.

Problems to be Solved by the Invention As described above, in the planar type magnetron sputtering apparatus, in order to block the magnetron operation, it is necessary to arrange the magnet on the opposite side of the target from the substrate. It is necessary to pass the magnetic flux from this magnet through the target so that the magnetic field strength component parallel to the target surface is 100 degrees or more to confine the charged particles, but when a magnetic target is used, the magnetic permeability of the target is 1 or more. Therefore, there was a drawback that it was difficult for the magnetic flux to penetrate the target.

Furthermore, most of the magnetic flux components leaving the magnet pass directly between the magnetic poles. This direct magnetic flux component 11 does not contribute to the magnetron operation; on the contrary, the presence of the direct magnetic flux component 11 reduces the effective component that penetrates the target.

Due to the difficulty of magnetic flux penetrating the target and the presence of the direct magnetic flux component 11, there has conventionally been a limit to the thickness of the target that can be used. Furthermore, even if a strong rare earth magnet is used, there is a problem in that the magnetic field strength is not sufficient for magnetron operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetron sputtering apparatus that overcomes the above-mentioned problems and can enhance the effective component of the magnetic flux that penetrates the target and improve the magnetron operation.

Means for Solving the Problems In order to achieve this object, the magnetron sputtering apparatus of the present invention has a structure in which a superconducting material is arranged around a charged particle confinement magnet arranged near the target.

Effect: With this configuration, the direct magnetic flux component that passes directly between the magnetic poles of the electromagnet is suppressed due to the Meissner effect of the superconducting material, and the effective component of the magnetic flux that passes through the target increases.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a main part of a magnetron sputtering apparatus according to an embodiment of the present invention.

In FIG. 1, 1 is a substrate, 2 is a magnetic target, and 3 is a substrate.
4 is a target outer peripheral wall, 4 is a shield portion, 5 is an insulating spacer, 6 is a permanent magnet, 7 is a yoke, and 12 is a coolant introduction tube for cooling the target. 9 is the magnetron parallel magnetic field region,
1o indicates the erosion area eroded by sputtering of the target. A superconductor 13 is arranged around the permanent magnet 6. The superconductor 13 is Y-Ba-
Liquid nitrogen, such as Cu-0, which has a critical temperature higher than liquid nitrogen temperature (77 K), is flowed through the target cooling refrigerant introduction pipe 12 to cool the target and maintain the superconductor 13 in a superconducting state.

The operation of the magnetron sputtering apparatus configured as described above will be explained below.

Since the superconductor 13 is arranged around the permanent magnet 6, the magnetic flux emitted from the permanent magnet 6 flows to avoid the superconductor 13 due to the Meissner effect of the superconductor 13. That is, in FIG. 1, the magnetic velocity emitted from the permanent magnet 6 all advances in the direction of the magnetic target 2, and the direct magnetic flux component 11 shown in FIG. 2 decreases. Therefore, even if the magnetomotive force of the magnet is the same, by disposing the superconductor 13, the magnetron parallel magnetic field region 9 can be expanded and the magnetic field strength can be increased compared to the conventional case.

In this embodiment, the magnetic target 2 is used as the target, but even if a non-magnetic target is used, the magnetron parallel magnetic field region 9 is expanded and the magnetic field strength is also increased compared to the conventional case. Further, although the permanent magnet 6 is shown in the embodiment as a magnetomotive force source, an electromagnet may be used.

Further, in this embodiment, liquid nitrogen is used as a coolant to maintain the superconductor 13 in a superconducting state, but if a superconductor whose critical temperature is close to room temperature is used, water may be used as the coolant.

Effects of the Invention The present invention makes it possible to expand the parallel magnetic field region of the magnetron by disposing a superconducting material around the magnet for charged particle confinement, and as a result, the erosion region of the target can be expanded more than before, which increases the effectiveness of the target. It becomes available for use. On the other hand, since the magnetic field strength also increases, the magnetron operation becomes active and the sputtering rate improves. Furthermore, since the magnetic field strength increases, it is possible to use a thicker target than in the past, making it possible to reduce target cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a magnetron sputtering apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of a conventional magnetron sputtering apparatus. 1...Substrate, 2...Target, 3.
...Target outer peripheral wall, 4...Shield part, 5...Insulating spacer, 6...Magnet, 7...Yoke, 9... ...Magnetron parallel magnetic field region, 13...Superconductor. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
Grave Plate 2 - Magnetic target 3 - Target outer wall 4 - Shields 5 - Insulating spacer 6 - Permanent magnet + 3 - JL body Figure 1 1 - @ Plate 6 - - Permanent magnet lO - Erosion 44 I area ++ --Series tangent magnetic flux component 1s2 diagram/

Claims (2)

[Claims] (1) A magnetron sputtering apparatus characterized in that a magnet for trapping charged particles is arranged near a magnetic target placed in a vacuum vessel, and a superconducting material is arranged around this magnet. (2) The magnetron sputtering apparatus according to claim 1, wherein the magnet for confining charged particles is an electromagnet.