JPH049469A - Planer type magnetron sputtering device - Google Patents

Abstract

PURPOSE:To uniformize the thickness and composition of the sputtered film on a base body by positioning the center of the magnets provided in the rear part of a disk type target to be in the outside of the orbit of the center of the base body moving in circular motion. CONSTITUTION:The center of the disk type target 18 fixed on a packing plate 20 is positioned right under the orbit 34 of the center of the base plate 10 moved in the circular motion by a pat 12. On the other hand, the center of the magnets 22, 24 provided in the back of the target 18 is positioned in the outside of the orbit 34 of the center of the base plate 10 so that the position of the center of the magnets 22, 24 is shifted from that of the target 18. Therefore, the horizontal component of the leak magnetic field 26 of the magnets 22, 24 above the target 18 is positioned in the outside of the orbit 34 of the center of the base plate 10. By this method, the film thickness distribution of the sputtered film formed on the base plate 10 is almost uniformized.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetron sputtering device that performs sputtering by leaking a magnetic field to the surface of a target serving as a cathode, and particularly relates to a planar type magnetron sputtering device in which the cathode is a flat plate. Regarding equipment.

[Conventional technology]

Magnetron sputtering devices can confine plasma near a target and efficiently eject particles from the target, so they are used for manufacturing semiconductor devices and forming recording films for optical disks such as magneto-optical disks. In particular, planar magnetron sputtering apparatuses in which the cathode is in the form of a flat plate are conveniently used because they can use a flat target. A planar type magnetron sputtering device (hereinafter simply referred to as a sputtering device) used in manufacturing optical disks is generally as shown in FIG.

That is, a bunt 12 to which a plurality of optical disc substrates 10 as a base body are attached is fixed to a rotating shaft 14, and the rotating shaft 14 rotates as indicated by an arrow 16. : and p, the substrate 10 is moved in a circular motion. A target 18 serving as a cathode is placed below the circularly moving substrate 10 facing the orbit of the substrate 10. Target 8 has a disk shape and is fixed on a backing plate 20. . On the back surface (lower surface) of this backing plate 20, there is a cylindrical magnet 22 whose upper side forms the north pole, and a magnet 22 arranged concentrically with the magnet 22.
A ring-shaped magnet 24 whose upper side forms the S pole is provided.

Further, the lower ends of these magnets 22 and 24 are connected by a yoke 25ζ forming a magnetic path. A leakage magnetic field 26 caused by the magnets 22 and 24 is formed above the target 18 in a ring shape with the magnet 22 at the center.

This leakage magnetic field 26 is as shown in FIG. 8 when the target 18 is A1 which is a non-magnetic material.
The vertical component of is large above the magnet 22, and the largest horizontal component is about 2 cm from the center. The appearance of this leakage magnetic field 26 is similar even when other non-magnetic materials are targeted. The AN target has a diameter of 20.32 cm (8 inches) and a thickness of 5 mm.
While a ferrite magnet is used as the magnet, if the target 18 is a ferromagnetic material, for example FeCoTi, the leakage magnetic field 26 will be as shown in FIG. 9, and if it is a microdomain type TbFeCo, It will look like Figure 10. Therefore, when the target 18 is a ferromagnetic material, the peak of the vertical component also shifts from the center, and the peak of the horizontal component moves further outward.

However, the FeCoTN target has a diameter of 20°3cm,
The thickness is 2.5 mm, and the TbFeCo target has a diameter of 20 mm.
3 cm and a thickness of 2.2 rr++n, and in each case, samarium kohar Nfi stone was used as the magnet.

In this way, the magnet 22.24 causes the target 18 to
A leakage magnetic field 26 is formed above the leakage magnetic field 2.
The horizontal component of 6 confines the discharge plasma populated by the voltage applied between the target 18 and an anode (not shown), forming a high density region of plasma in the vicinity of the target 18. Then, the plasma restrained by the leakage magnetic field 26 causes the magnets 22 and 24 ([between the poles]) to swell and swell, and ejects particles 28 such as atoms forming the target 18 toward the substrate 10. At the same time, erosion 3o is generated in the target 18.

In the above sputtering apparatus, a comparatively uniform and homogeneous sputtered film can be obtained by forming a film while the group #Ii, 10 and the target #8 are statically opposed to each other. However, when the substrate 10 is moved in a circular motion around the rotating shaft 14, the linear velocity is small on the inside (on the rotating shaft 14 side) of the orbit of the center of the substrate 10, and increases on the outside. The speed is not uniform, and the thickness of the formed film becomes thinner on the outside as shown by the solid line in FIG. 1I, and the composition is also non-uniform.

Therefore, in order to solve this problem, Figures 12 and 13
As shown in the figure, a shielding plate called a distribution correcting plate 32 is provided between the circularly moving substrate 10 and the target 18 to make the film thickness uniform. Then, this distribution correction plate 32
By using this method, the thickness of the sputtered film formed can be made relatively uniform, as shown by the broken line in FIG.

C Problems to be Solved by the Invention] However, when trying to make the film thickness uniform using the distribution correction plate 32 as described above, the reference for the thickness of the deposited film, that is, the reference for the deposition rate, is set to the substrate. The film forming speed must be set to the position farthest from the rotation axis 14 of 10. For this reason, not only the film formation rate decreases by about 10 to 30%, but also the usage efficiency of the target 18 decreases because the particles 28 from the target 18 are made to adhere to the distribution correction plate 32. Moreover, if sputtering is performed for a long period of time, the distribution correction plate 3
2 is scattered as dust and causes defects such as pinholes in the film formed on the substrate 10.

The present invention has been made to eliminate the drawbacks of the prior art, and an object of the present invention is to provide a planar type magnetron sputtering apparatus that can form a uniform sputtered film without using a distribution correction plate.

[Means to solve the problem]

In order to achieve the above object, the planar magnetron sputtering apparatus according to the present invention arranges a target facing a circularly moving substrate, and has N and S poles of a magnet behind the target. A planar type magnetron sputtering apparatus having concentrically arranged planar magnetron sputtering apparatuses is characterized in that the distribution center of particles emitted from the target is set outside the orbit through which the center of the circularly moving base passes.

If the center of distribution of particles emitted from the target is to be outside the orbit of the center of the base body moving in a circular motion, the center position of the target and the center position of the magnet are shifted, and the center position of one of them is moved in a circular direction. This can be achieved by placing it outside the orbit through which the center of the moving base body passes.

When the center 1 of the magnet is placed outside the orbit through which the center of the circularly moving base passes, the outer diameter of the ring-shaped outer magnet is preferably smaller than the outer diameter of the target.

Further, when the center position 1 of the target is placed outside the orbit through which the center of the circularly moving base passes, the dimension of the target can be made smaller than the outer diameter dimension of the magnet. In addition,
The target and the magnet are preferably provided so as to be relatively rotatable.

[Function] The present invention configured as described above sets the center of distribution of particles emitted from the target outside the trajectory of the center of the circularly moving substrate, so that The amount of particles from the target reaching the outer portion of the circular motion is greater than the portion of the base closer to the center of the circular motion, and the thickness and composition of the sputtered film formed on the base can be made uniform.

As a result, there is no need to correct the film thickness using a distribution correction plate, and it is possible to improve the film formation rate and the utilization efficiency of the target 7). Moreover, the particles attached to the distribution correction plate are not scattered as dust, and the formation of pinholes in the formed film can be prevented, so that a film with high reliability can be formed.

If the center of distribution of particles emitted from the target is to be outside the orbit of the center of the circularly moving base, the center position of the target and the center position of the magnet are shifted, and the center position of either one is shifted. This can be easily achieved by placing the center of the base body in circular motion outside the orbit.

If the center of the magnet is placed outside the orbit that the center of the circularly moving base passes through, if the outer diameter of the ring-shaped outer magnet is smaller than the outer diameter of the target, the area where the magnet is placed will be The target is subjected to magnetron sputtering, and the part of the substrate that is moving in a circular motion, where the magnet is not located, is subjected to normal sputtering, which allows for good uniformity of the sputtered film. .

In addition, when the center position of the target is placed outside the orbit through which the center of the circularly moving base passes, if the dimension of target 7) is made smaller than the outer diameter of the magnet, it is necessary to use a large and expensive target. do not have.

By providing the target and the magnet so that they can rotate relative to each other, the locations where erosion occurs on the target can be made different, making it possible to significantly improve the utilization efficiency of the target.

〔Example〕

A preferred embodiment of the planar magnetron sputtering apparatus of the present invention will be described in detail with reference to the accompanying drawings. Note that the same reference numerals are given to the parts corresponding to the parts explained in the prior art, and the explanation thereof will be omitted.

FIG. 1 is an explanatory diagram of a planar magnetron sputtering apparatus according to a first embodiment of the present invention, and FIG. 2 shows the positional relationship between a target and a magnet with respect to the orbit of the center of a substrate.

In these figures, a disc-shaped target 18 is fixed on the backing plate 20. The intermediate portion 4 of this target 18 is located directly below the trajectory 34 through which the center of the substrate 10 that is moved in a circular motion by the bat 12 passes.

On the other hand, magnets 22 and 24 provided at the bottom of the backing plate 20, that is, behind the target 18, are so-called S
A magnet 22 serving as an N pole is arranged at the center of a ring-shaped magnet 24 serving as a pole. The outer diameter of the ring-shaped magnet 24 is smaller than the diameter of the target 18, and the center of the magnet 22.24 moves circularly on the substrate 1.
Target 1 is located outside the trajectory 34 through which the center of
The center positions of magnets 22 and 24 are shifted from each other.

Therefore, the horizontal component of the leakage magnetic field 26 above the target 18 due to the magnets 22, 24 is outside the trajectory 34 through which the center of the substrate 10 passes, as shown by the two-dot chain line in FIG.

Therefore, since most of the particles emitted from the target 1B are sputtered by the discharge plasma restrained by the leakage magnetic field 26, the distribution center is outside the orbit 34 that the center of the substrate 10 passes, and the target 18
The part of the substrate 10 on the center side of the circular motion where the magnets 22 and 24 are not placed is subjected to normal sputtering.

When a sputtered film was formed using the sputtering apparatus configured as described above, the thickness distribution of the sputtered film formed on the substrate 10 could be made almost uniform, as shown by the solid line in FIG. Note that the target 18 used was FeC as a ferromagnetic material.

The magnet 24 has a diameter of 20.32 cm (8 inches), and the outer diameter of the magnet 24 is 15.24 cm (6 inches).
The center position of 2.24 was shifted from the center position of the target 18 by about 1/4 of the radius of the target 18 to the outside of the trajectory through which the center of the substrate 10 passes. In addition, the ultimate vacuum level is 5X10
-' In the following, the sputtering gas pressure was set to 2 mTorr, and the input power of the Sunoku Tsutering was set to 0.5 to 3 kW.
0 was rotated (circular motion) at 5 to 10 rpm.

As a result, not only was a sputtered film with a uniform thickness obtained, but also because no distribution correction plate was used to block the particles emitted from the target 8, the particles emitted from the target 1B were efficiently transferred to the substrate 10. can be reached,
Compared to the case where a distribution correction plate is used, the film formation speed has been reduced by 2
It was possible to improve the utilization efficiency of target 18 by about 0%. In addition, since no distribution correction plate is used, the particles attached to the distribution correction plate will not be scattered again as dust, reducing defects such as contaminating the formed film and causing pinballs. A sputtered film with high properties was obtained.

In the above embodiment, the case where the center position of the target 18 and the center position 1 of the magnet 22.24 are deviated from each other is explained. The center position may be set outside the orbit 34 through which the center of the substrate 10 passes. And magnet 2
2. The size and arrangement position of 24 are determined as appropriate depending on the sputtering apparatus by experiment, solar cell, etc.

FIG. 4 is an explanatory diagram of the second embodiment, and FIG. 5 is a diagram showing the relationship between the trajectory of the center of the substrate, the target, and the magnet.

In these figures, the magnets 22, 24 provided at the bottom of the hunk plate 20 are arranged concentrically, and their centers are directly below the track 34 through which the center of the circularly moving substrate 10 passes. Further, the target 18 fixed on the banking plate 20 has a diameter smaller than the outer diameter of the ring-shaped magnet 24, and the center position of the target 18 is set on a trajectory 34 in which the center of the substrate 10, which moves in a circular motion, is close. It is located on the outside.

Therefore, the horizontal component of the leakage magnetic field 26 above the target 18 due to the magnets 22, 24 is approximately symmetrical with respect to the center of the substrate 10, as shown by the two-dot chain line in FIG. However, because the position of the target 18, which is formed smaller than the magnet 24, is shifted, the sputtering portion of the rotation axis 14 of the target 18 is small (target 1
The center of the distribution of particles emitted from the substrate 8 is located outside the trajectory 34 through which the center of the circularly moving substrate 10 passes. Therefore, the thickness of the sputtered film formed on the substrate 10 is substantially uniform, and the same effects as in the previous embodiment can be obtained.

The inventors created a magnet 2 with an outer diameter of 20.32 cm (8 inches).
4 and a target 18 with a diameter of 15.24 cm (6 inches).
When sputtering was performed by shifting the center position of the target 1H from the center position of the magnets 22 and 24 by about 1/4 of the radius of the magnet 240 to the outside of the orbit through which the center of the substrate 10 passes, the solid line in FIG. A film thickness distribution as shown was obtained. The type of target used, experimental conditions, etc.
This is the same as in the previous embodiment.

In addition, in each of the above embodiments, the target 18 and the magnet 2
If the target 18 and the magnet 22.24 are configured to be able to rotate relative to each other, and either or both of the target 18 and the magnet 22.24 are rotated about their respective centers, the relative rotation between the target 18 and the magnet 22.24 is The position changes and target 18
The part of the air gap 30 formed on the surface moves, and the utilization efficiency of the target 18 can be greatly improved. Further, in the embodiments described above, the formation of a sputtered film on a magneto-optical disk has been described, but the present invention can also be applied to the manufacture of other optical disks or semiconductor devices.

〔Effect of the invention〕

As explained above, according to the present invention, by setting the distribution center of particles emitted from a target to be outside the orbit through which the center of the substrate moving in a circular motion passes, The amount of particles reaching the outer portion of the circular motion of the substrate is larger than that of the portion of the substrate closer to the center of the circular motion, and the thickness and composition of the sputtered film formed on the substrate can be made uniform.

As a result, there is no need to correct the film thickness using a distribution correction plate, and it is possible to improve the film formation rate and target utilization efficiency. However, the particles attached to the distribution correction plate are not scattered as dust, and the formation of pinholes in the formed film can be prevented, making it possible to form a highly reliable sputtered film.

If the center of distribution of particles emitted from the target is to be outside the orbit of the center of the circularly moving base, the center position of the target and the center position of the magnet are shifted, and the center position of either one is shifted. This can be easily achieved by placing the center of the base body in circular motion outside the orbit.

If the center of the magnet is placed outside the trajectory of the center of a circularly moving base, the outer diameter of the ring-shaped outer magnet should be smaller than the outer diameter of the target. The part of the target is subjected to magnetron sputtering, and the part inside the orbit through which the center of the circularly moving base body, where the target magnet is not located, is subjected to normal sputtering, making it possible to achieve good uniformity of the sputtered film. .

Further, when the center position of the target is placed outside the orbit through which the center of the circularly moving base passes, if the size of the target is made smaller than the outer diameter of the magnet, there is no need to use a large and expensive target.

By providing the target and the magnet so that they can rotate relative to each other, the locations where erosion occurs on the target can be made different, making it possible to significantly improve the utilization efficiency of the target.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a planar type magnetron sputtering device according to the first embodiment of the present invention, and FIG. 2 shows the relationship between the trajectory of the center of the substrate, the target 7, and the magnet in the first embodiment. FIG. 3 is a diagram showing the distribution of leakage magnetic fields between the substrate and target of the first embodiment, FIG. 4 is an explanatory diagram of the second embodiment, and FIG. FIG. 6 is a diagram showing the relationship between the trajectory, target, and magnet, and FIG.
The figure is an explanatory diagram of a conventional planar type magnetron sputtering apparatus. Figures 8 to 10 are illustrations of the leakage magnetic field above the target in a conventional planar type magnetron sputtering apparatus. An explanatory diagram of the relationship between the leakage magnetic field and the film thickness distribution of the sputtered film formed. Fig. 12 is an explanatory diagram of a conventional planar type magnetron sputtering apparatus having a distribution correction plate. Fig. 13 is a diagram showing the state in which the distribution correction plate is used. It is. 10...-Base (substrate), 14 °゛-゛・Rotation axis, 18...-Target, 22.24--One magnet, 3
4 orbits.

Claims (5)

[Claims] (1) A target is placed facing the base that is moving in a circular motion, and the north and south poles of the magnet are placed behind this target.
A planar type magnetron sputtering device in which a pole and a pole are provided concentrically, wherein the distribution center of particles emitted from the target is set outside the orbit through which the center of the circularly moving base passes. type magnetron sputtering equipment. (2) The center position of the target and the center position of the magnet are shifted from each other, and one of the center positions is set outside the orbit along which the center of the circularly moving base body passes. The planar magnetron sputtering device described in . (3) The center position of the magnet is located outside the orbit through which the center of the circularly moving base passes, and the outer diameter of the ring-shaped outer magnet is smaller than the outer diameter of the target. The planar type magnetron sputtering apparatus according to claim 2, characterized in that: (4) A dimension of the target is formed to be smaller than an outer diameter dimension of the magnet, and a center position of the target is located outside a trajectory along which the center of the circularly moving base passes. 2. The planar magnetron sputtering apparatus according to 2. (5) The target and the magnet are capable of relative rotation.
The planar magnetron sputtering device described in .