JPH0222468A - Magnetron sputtering device - Google Patents

Abstract

PURPOSE:To enhance the collection density of plasma and to improve sputtering velocity by providing a superconducting material to the periphery excepting the upper surface of a double-structure magnet built-in to the inside of the supporting body of a target so that the magnet is covered therewith and inhibiting generation of magnetic lines of force. CONSTITUTION:A double-structure magnet 3 is built-in to the inside of the supporting body 4 of a target and the target 6 is fitted on the supporting body 4 via a nonmagnetic packing plate 5 and opposed to a base plate on which a thin film is formed. At this time, a superconducting material 21 is provided to the periphery excepting the upper surface of the magnet 3 so as to cover the magnet and a containing part 22 for containing a refrigerant 23 cooling the superconducting material 21 at its critical temp. or below is provided. In the case of performing sputtering in this constitution, the superconducting material 21 is cooled by the refrigerant 23 and made a superconducting state and completely made diamagnetism and thereby magnetic lines of force are inhibited from being generated from the periphery excepting the upper surface of the target 3. Thereby an arc-like magnetic field 10 is efficiently generated on the surface of the target 3 and the collection density of plasma is enhanced and the thin film is efficiently formed on the base plate at the large sputtering velocity.

Description

[Detailed Description of the Invention] [Summary] Regarding a magnetron sputtering device suitable for use in manufacturing various magnetic films and semiconductor integrated circuit elements, etc., this invention relates to a magnetron sputtering device suitable for use in manufacturing various magnetic films, semiconductor integrated circuit elements, etc. The purpose of this method is to easily prevent non-contributing lines of magnetic force and efficiently generate an arc-shaped magnetic field on the target surface from the magnet, thereby increasing the sputtering speed. In a magnetron sputtering apparatus, a substrate on which a thin film is to be formed is placed facing the target, and a target material is deposited on the substrate in a state where a sputtering gas atmosphere is created in a vacuum chamber containing the substrates, A superconducting material is provided so as to cover the periphery of the magnet other than the surface thereof, so as to prevent the generation of magnetic lines of force from the periphery other than the surface of the magnet.

[Industrial application field]

The present invention relates to a magnetron sputtering apparatus suitable for manufacturing various magnetic films, semiconductor integrated circuit elements, etc., and particularly relates to a target support structure.

Magnetron sputtering equipment has a faster film formation rate than commonly used sputtering equipment, and can easily form not only metal thin films but also various compound thin films such as oxides, nitrides, and sulfides. Because it can form a film, it is widely used in the manufacture of magnetic recording media, thin-film magnetic heads, semiconductor devices, etc.

In such magnetron sputtering equipment, in order to focus plasma gas ions on the target at high density using a magnetic field during sputtering and increase the sputtering speed at a relatively low voltage, the target is placed on a support part with a built-in magnet. Although the magnet is attached via a banking plate or the like, lines of magnetic force that do not contribute to sputtering from parts other than the magnet surface tend to wrap around the magnet surface and reduce sputtering efficiency. For this reason, it is desired to prevent such lines of magnetic force from going around and improve sputtering efficiency.

[Conventional technology]

As shown in FIG. 3, a conventional magnetron sputtering apparatus has a central cylindrical magnet 3a and an annular magnet 3a magnetically coupled to each other by a yoke 3C, for example, on the base body la side of a vacuum chamber 1 to which a vacuum evacuation device 2 is attached. magnet 3
A water-cooled target support 4 having a built-in double-structured magnet 3 consisting of a magnet 3 and a magnet 3 is disposed.

Further, a target 6 attached to a non-magnetic backing plate 5 made of copper (Cu) or the like was attached on the target support 4, and supported a substrate 8 on which a thin film was to be formed in opposition to the target 6. A substrate support 7 is arranged on the cover 1b side of the container 1.

In order to form a thin film on the surface of the substrate 8 supported on the substrate support 7 using such a sputtering device, Ar gas is introduced into the vacuum chamber 1 which is evacuated to a predetermined degree of vacuum by the vacuum evacuation device 2. For example, use a sputtering gas such as
After introducing several mTorr, a voltage of several kV is applied between the target 6 and the substrate support 7 from the power supply section 9 to generate plasma discharge.

The electrons in the plasma generated at this time are transferred to the magnet 3.
The arc-shaped magnetic field 10 shown by the chain line generated on the surface of the target 6 ionizes the sputtering gas molecules while making a cycloidal motion.

These ionized plasma-like sputtering gas ions are further focused on the surface of the target 6, so they are accelerated and collide with the surface of the target 6, sputtering the target material from the surface and sputtering a large amount onto the opposing substrate 8. Forms a thin film at a deposition rate.

[Problem to be solved by the invention]

By the way, in the target support structure in the conventional magnetron sputtering apparatus as described above, as shown in FIG.
An arcuate magnetic field 10 is generated on the surface of the magnet 3, but in addition to this, lines of magnetic force 11a that do not contribute to sputtering extend from the back side of the magnet 3 to the front side, and the center circle forming the magnet 3 Columnar magnet) 3a
Since many lines of magnetic force 11b that do not contribute to the sputtering occur between the side surfaces of the annular magnet 3b and the annular magnet 3b, there is a problem that the sputtering efficiency is reduced.

In view of the above-mentioned conventional situation, the present invention simply prevents magnetic lines of force that do not contribute to sputtering generated from the side and back sides of the magnet built in the target support.
It is an object of the present invention to provide a novel magnetron sputtering apparatus that improves sputtering speed by efficiently generating an arcuate magnetic field on the target surface from the magnet.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention arranges a target on a double-structured magnet, and also arranges a substrate on which a thin film is to be formed on the target, and creates a sputtering gas atmosphere in a vacuum container containing the targets. In an apparatus configuration in which a target material is deposited and formed on the substrate in a state where the magnet is in a state of composition.

[For production]

In the target support structure in the magnetron sputtering apparatus of the present invention, for example, Y-Ba-Cu-0, etc. By cooling the superconducting material to a temperature below its critical temperature during sputtering, the superconducting material becomes completely diamagnetic due to the Meissner effect, and magnetism from the surroundings other than the surface of the magnet is removed. Generation of magnetic lines of force that do not contribute to sputtering is prevented.

Therefore, the magnetic field generated on the target is greater than that on the magnet surface, and the focused density of the plasma is increased. As a result, sputtering speed can be increased.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic side sectional view showing an embodiment of a magnetron sputtering apparatus according to the present invention, and parts equivalent to those in FIG. 3 are given the same reference numerals.

The difference between the embodiment shown in this figure and the example shown in FIG. For example, Y-Ba-Cu-0 is applied to each side surface of the columnar magnet 3a and the annular magnet 3b, and to the back surface of the yoke 3c that magnetically couples both magnets 3a and 3b.
The superconducting material 21 made of etc. is provided in a covered state, and
The target support 4 is provided with a refrigerant accommodating portion 22 for accommodating a refrigerant 23 for cooling the superconducting material 21 below its critical temperature.

In such a target support structure, as shown in the partially enlarged sectional view of FIG. 2, during sputtering, a coolant 23 made of, for example, liquid nitrogen is injected into the coolant storage section 22 in the target support 4 to cool the superconducting material 21. Cool below its critical temperature.

In this case, the target 6, which was conventionally cooled by a water cooling method, is also cooled.

When Y-Ba-Cu-0 is used as the superconducting material 21, its critical temperature is about 90°C, so it becomes sufficiently superconductive at liquid nitrogen temperature (77K), and due to the complete diamagnetic property due to the Meissner effect, Generation of lines of magnetic force that do not contribute to sputtering from the surroundings other than the surface of the magnet 3 is prevented.

Therefore, it becomes possible to efficiently generate an arcuate magnetic field 10 from the magnet 3 on the surface of the target 6 through the backing plate 5, and because the concentration density of plasma increases, a large Thin films can be efficiently formed at sputtering speeds.

In the above embodiment, if all the side surfaces of the double-structured magnet 3 are covered with the superconducting material 21 to form a completely closed circuit, no magnetic field will be generated from the magnet 3. It is necessary to provide a slit in a suitable part of the superconducting material 21 to prevent a completely closed circuit.

Furthermore, when the periphery of the double-structured magnet 3 other than the surface is covered with the superconducting material 21, the yoke 3c magnetically couples the central cylindrical magnet 3a and the annular magnet 3b that constitute the magnet 3. Since more magnetic flux flows than in the past, it is necessary to increase the thickness of the yoke 3c to prevent magnetic saturation.

〔Effect of the invention〕

As is clear from the above description, according to the magnetron sputtering apparatus according to the present invention, since an arc-shaped magnetic field can be efficiently generated on the target surface by the magnet, the concentration density of plasma during sputtering increases, It has excellent practical effects, such as increasing the sputtering speed and making it possible to form a film at a higher speed than before.

Therefore, it is extremely advantageous to apply this type of magnetron sputtering apparatus.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view showing an embodiment of a magnetron sputtering device according to the present invention, FIG. 2 is a partially enlarged sectional view showing a target support structure of the present invention, and FIG. 3 illustrates a conventional magnetron sputtering device. A schematic side sectional view of the sputtering device. FIG. 4 is a partially enlarged sectional view for explaining the problems of the target support structure in a conventional magnetron sputtering apparatus. In Figures 1 and 2, 1 is a vacuum vessel, 2 is an exhaust system, and 3 is a mag-secret FJR/17.
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Claims (1)

[Claims] A target (6) is placed on a double-structured magnet (3), and a substrate (8) on which a thin film is to be formed is placed facing the target (6), and these are accommodated. The substrate (8) is placed in a sputtering gas atmosphere in the vacuum container (1).
), in which a superconducting material (2
A magnetron sputtering apparatus characterized in that it is provided so as to cover the magnet (3) to prevent the generation of magnetic lines of force from the surrounding area other than the surface of the magnet (3).