JPH1161396A - Sputtering equipment - Google Patents

Abstract

(57) [Problem] To provide an efficient and economical sputtering apparatus. SOLUTION: In a sputtering apparatus 20 in which a cathode portion 24 is provided in a vacuum vessel 21 to perform sputtering on an object, the cathode portion 24 is disposed to face the object B, and is applied to the object B. And a backing plate portion 26 provided on the back side of the target portion 25 and made of the same material as the target portion 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a sputtering apparatus, and more particularly to a sputtering apparatus capable of performing sputtering efficiently and economically.

[0002]

2. Description of the Related Art A disk-shaped recording medium such as a magneto-optical disk or an optical disk is a disk-shaped recording medium capable of recording a large amount of information. FIG. 6 is a sectional view of an optical disk, for example. As shown in FIG. 6, a functional thin film layer (recording layer) 3 such as a recording film is formed on a disk substrate 2 made of a plastic material such as polycarbonate, and the functional thin film layer 3 is protected with an ultraviolet curing resin or the like. To form a recording layer protective film 4 for performing the following. The optical disk 1 has a three-layer structure or a four-layer structure in which a substrate protective film 5 is further added to protect the disk substrate 2.

[0006] The functional thin film layer 3 shown in FIG. 6 is usually formed by a sputtering apparatus. The sputtering device is a device in which an ionized argon gas collides with a target material provided on a cathode electrode, and atoms ejected by the impact are stacked on a disk substrate or the like provided on the anode side. In general, a sputtering apparatus maintains a stable discharge state by reducing the gas pressure in order to prevent impurities from being mixed into the thin film. Among the sputtering apparatuses, a magnetron sputtering apparatus having a particularly high film forming rate is generally used. The magnetron sputtering apparatus increases the sputtering efficiency by confining the plasma in the magnetic field of a magnet arranged on the back side of the target.

FIG. 7 is a sectional view of a cathode section 10 in a conventional magnetron sputtering apparatus. 7 includes a target 11, a backing plate 12, a cooling unit 13, a magnet 14, a case 15, and the like. The cathode unit 10 in FIG. 7 has a case 15 as a housing on the outside, and a target 11 is provided on the right side of the case 15. Target 1 in FIG.
Numeral 1 is made of a magnetic metal material or a non-magnetic material forming a thin film, and is provided so as to face an object such as an optical disk substrate on which the thin film is formed. As shown in FIG. 8, the target 11 of FIG.
It is attached using an In-based bonding material 16 such as n-Sn or In-Pb. The backing plate 12 is made of a material having good conductivity such as oxygen-free copper. The cooling means 13 flows cooling water for discharging heat generated on the target 11 by sputtering into the case 15.

On the left side of the backing plate 12 shown in FIG. 7, magnets 14a and 14b for generating a magnetic field on the target 11 are provided. The magnets 14a and 14b in FIG. 8 are magnets having different polarities and form a closed magnetic field on the target 11 from the direction 14a to the direction 14b. Electrons generated from the cathode of the electric field perform cyclonic motion by the electric field and the magnetic field formed by the magnets 14a and 14b. Argon ions are formed by collision of the cyclone-moving electrons with the argon gas, and the argon ions collide with the target 11. As a result, target atoms are emitted from the target 11 and adhere to an object on the anode side of the electric field, thereby forming a thin film.

[0006]

The argon ions are confined in the magnetic field formed by the magnets 14a and 14b, and the ion concentration increases in the closed magnetic field. Sputtering is intensively performed at a portion where the ion concentration is high, and an eroded region is formed on the target 11 (erosion region). As the sputtering proceeds, the erosion region expands, and the bottom surface 11a of the target 11 in FIG.
The erosion area reaches the lower side of the target 11
There is a possibility that sputtering may be performed up to the bonding material 16 or the backing plate 12 that bonds the backing plate 12 with the bonding material 16. When sputtering is performed not only on the target 11 of FIG. 8 but also on the bonding material 16 or the backing plate 12, impurities such as copper, which is the material of the bonding material 16 and the backing plate 12, are contained in the thin film of the object such as a disk substrate. As a result, predetermined characteristics of the thin film cannot be obtained, and there is a problem that quality is deteriorated.

In order to prevent the deterioration of the quality of the optical disk 1 and the like, it is necessary to stop sputtering before the erosion area of the target 11 reaches the bonding material 16 or the backing plate 12 and replace the target 11 with a new one. is there. Specifically, when the erosion region reaches about 0.5 mm to 1.0 mm from the bottom surface 11a of the target 11 by sputtering, the sputtering is stopped and a new target 1
Replace with 1. However, when there is a region where the target 11 cannot be sputtered by a predetermined thickness when sputtering the target 11, there arises a problem that the use efficiency of the target (the ratio of the consumable volume to the volume of the target before use) decreases. Would. Further, there is a problem that a cycle (target life) for replacing the target 11 is shortened, and labor of an operator is required.

Further, the sputtering target 11 is subjected to a process for reuse, and the target 1
1 is recycled. When the target 11 is recycled, first, the bonding material 16 that adheres the target 19 and the backing plate 12 is melted, the target 11 is peeled off from the backing plate 12, and then the bonding material 16 that is adhered to the target 11 is removed.
The problem is that the process of removing satisfactorily is performed, which is troublesome and costly.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide an efficient and economical sputtering apparatus.

[0010]

According to the present invention, there is provided a sputtering apparatus for performing sputtering on an object by providing a cathode portion in a vacuum vessel.
The cathode portion is disposed to face the object, and has a target portion made of a material applied to the object, and a backing plate portion provided on the back side of the target portion and made of the same material as the target portion. This is achieved by a sputtering device.

In the present invention, the target portion and the backing plate portion are formed of a thin film material, and sputtering is performed using this target. This allows
Even if the erosion area extends to the backing plate portion, it is possible to prevent the quality of the thin film formed on the object from deteriorating. In addition, by using the backing plate portion as a region where the sputtering portion can be formed, the target replacement cycle can be lengthened.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 is a system diagram showing a preferred embodiment of the sputtering apparatus of the present invention. The sputtering apparatus 20 will be described in detail with reference to FIG.
The sputtering apparatus 20 in FIG.
It has a vacuum control unit 22, a sputtering gas supply unit 23, a cathode unit 24, a power supply 31, an anode unit 33, and the like.

The vacuum chamber 21 shown in FIG.
And the vacuum controller 22 is connected to the vacuum chamber 21.
The inside of the vacuum chamber 21 is maintained at a vacuum by discharging the air inside. A sputtering gas supply unit 23 is disposed in the vacuum chamber 21 of FIG. 1, and the sputtering gas supply unit 23 flows a sputtering gas such as an argon gas (Ar) into the vacuum chamber 21. At this time, the vacuum chamber 2
The sputtering gas pressure in 1 is maintained at, for example, about 0.1 Pa to 1.0 Pa by the vacuum controller 22. Sputtering is performed by ionizing the argon gas of FIG. 1 and colliding with ions of the target portion 25 of the cathode portion 24.

In the vacuum chamber 21 shown in FIG. 1, a target portion 25 of a cathode portion 24 and an anode portion 33 are provided so as to face each other at a predetermined distance. An object B such as a disk substrate on which a thin film is to be formed is disposed on the anode portion 33 of FIG. 1 so as to face the target 25 of the cathode portion 24. The thin film is formed by attaching target atoms. You. A cooling unit (not shown) is connected to the anode unit 33 in FIG. 1, and the cooling unit lowers the temperature of the heated object B and protects the object B from heat generated during sputtering. A power supply 31 is connected to the cathode section 24 and the anode section 33 in FIG.
An electric field is formed from the cathode section 24 toward the anode section 33. As a result, electrons are emitted from the negative electrode of the power supply 31 toward the anode.

FIG. 2 is a sectional view of the cathode section 24, and FIG. 3 is a top view of the cathode section 24. The cathode section 24 will be described in detail with reference to FIGS. The cathode section 24 in FIG. 2 is a circular cathode electrode as shown in FIG.
6, case 28, cooling means 29, magnets 30a, 3
0b and the like. The outside of the cathode unit 24 in FIG. 2 is covered with a case 28, and a target 25 is disposed on the right side of the cathode unit 24. 2 is made of a metal magnetic material such as Al or Al—Ti, and a thin film is formed by attaching target atoms to the target B.

FIG. 4 is a cross-sectional view taken along the line AOA of FIG. 3. The target portion 25 and the backing plate portion 26 will be described in detail with reference to FIG. The target portion 25 and the backing plate portion 26 in FIG. 4 are made of the same material and are integrally formed. The target portion 25 and the backing plate portion 26 in FIG.
It is made of an Al-based material such as l-Ti. The thickness L1 of the cathode portion 25 in FIG. 4 is, for example, 8 mm, and the diameter L3 is, for example, 127 mm. The thickness L2 of the backing plate portion 26 in FIG. 4 is, for example, 6 mm, and the diameter L4 is, for example, 154.5 mm. The backing plate portion 26 in FIG. 4 has a locking piece 26b on the side surface, and the target portion 25 and the backing plate portion 26 are fixed to the case 28 by the locking piece 26b.

A cooling means 29 is provided on the left side of the backing plate section 26 in FIG. 2, and the cooling means 29 has two pipes 29a and 29b. Cooling water flows in the direction of the arrow X1 in the pipe 29a of FIG.
Cooling water flows out of the pipe 29b in the X2 direction. The cooling water deprives the heat generated in the backing plate part 26 of FIG. 2 and cools the backing plate part 26,
The temperature of the target section 25 is lowered to protect the target section 25 and the backing plate section 26 from plasma heat.

Referring to FIGS. 2 and 3, magnet 30a,
30b will be described in detail. Magnet 30 of FIG.
a, 30b are provided on the left side of the backing plate portion 26. 2 is arranged at the center of the target 25, and the magnet 30b is arranged at the periphery of the target 25. As shown in FIG. 2, a curved magnetic field is formed from the magnet 26a toward the magnet 26b. Due to this magnetic field and the electric field from the target unit 25 to the anode unit 33, electrons emitted from the cathode perform cyclone motion and collide with argon gas,
Generates ions.

Next, the operation of the sputtering apparatus will be described in detail with reference to FIGS. First, the inside of the vacuum chamber 21 in FIG. 1 is evacuated by the vacuum control unit 22, and then an argon gas as a sputtering gas flows in from the sputtering gas supply unit 23. At this time, the sputtering gas pressure in the vacuum chamber 21 is maintained at about 0.1 Pa to 1.0 Pa by the vacuum control unit 22. An electric field from the cathode section 24 to the anode section 33 is formed by the power supply 31 in FIG. 1, and electrons that are cyclone-moving by the electric field and the magnetic field collide with the argon gas. Argon ions are generated in between. Then, the target atoms are emitted from the target portion 25 by the collision of the argon ions shown in FIG. The target atoms are attracted to the anode 33 on the anode side of the electric field, and adhere to the target B provided on the anode 33 to form a thin film.

In the above embodiment, the target 25
And the backing plate 26 are integrally formed of the same material, and a bonding material for bonding the target portion 25 and the backing plate portion 26 is not used between the target portion 25 and the backing plate 26. Accordingly, it is possible to prevent the quality of the target object from being deteriorated due to sputtering of impurities other than the thin film forming material.
That is, when the depth of the erosion region formed on the target portion 25 becomes larger than the thickness L1 of the target portion 25 as the sputtering proceeds as shown in FIG. 5, the erosion region reaches the backing plate portion 26. However, the backing plate 26 is the target 2
Since it is made of the same material as that of No. 5, that is, a magnetic metal material forming a thin film, there is no danger of impurities being mixed into the thin film formed on the object. Further, since the target portion 25 and the backing plate portion 26 are formed integrally, it is possible to prevent the adhesive such as the bonding material 16 from being mixed in the thin film.

Further, since the target portion 25 and the backing plate portion 26 are integrally formed, recycling of the target material is facilitated. That is, the target unit 25
In the process of reworking the target material when the target portion 25 is reused, the target and the backing plate are separated and adhered to the target because the bonding material for bonding the backing plate portion 26 to the backing plate portion is unnecessary. Since there is no need to remove the existing bonding material, reuse becomes easier.

Since the backing plate portion 26 of FIG. 4 is made of a material to be formed on the object B, the region of the backing plate portion 26 can also be used as a target region for forming a thin film. Thereby, the target unit 2
5 is increased by the thickness L2 of the backing plate 26, and the number of optical disks that can be formed into a thin film with one target can be increased, for example, by about 1.5 times. it can. Increasing the number of thin film forming targets reduces the cost of material per optical disc and reduces the work of replacing targets.

The present invention is not limited to the above embodiment. The sputtering apparatus of the above embodiment,
Although an optical disk, a magneto-optical disk, and the like are sputtered, a liquid crystal substrate or a magnetic information recording medium may be used for sputtering. Target 2 in Figure 2
1 is a circular target, but may be a rectangular target. Although the magnets 30a and 30b are used to generate a magnetic field on the target 21, the magnetic field may be formed using an electromagnetic coil or the like. Further, in the above embodiment, the target surface portion is disposed in the vacuum chamber (internal cathode), but the entire cathode section may be disposed in the vacuum chamber (external cathode).

[0025]

As described above, according to the present invention,
An efficient and economical sputtering apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a preferred embodiment of a sputtering apparatus of the present invention.

FIG. 2 is a sectional view showing a cathode portion of the sputtering apparatus of FIG.

FIG. 3 shows a top view of the cathode unit of FIG.

FIG. 4 is a view showing an AOA cross section of the cathode unit of FIG. 2;

FIG. 5 is a cross-sectional view showing an erosion region formed when a target portion is sputtered.

FIG. 6 is a sectional view showing a configuration of a general optical disc.

FIG. 7 is a sectional view showing a cathode portion of a conventional sputtering apparatus.

FIG. 8 is a cross-sectional view of a target showing an erosion region when sputtering is performed in a conventional sputtering apparatus.

[Explanation of symbols]

Reference Signs List 20 sputtering device, 21 vacuum chamber, 22 vacuum control unit, 23 sputtering gas supply unit, 24 cathode unit, 25 target unit, 26 backing Plate part, B: target object (disk substrate).

Claims (3)

[Claims] 1. A sputtering apparatus for performing sputtering on an object by providing a cathode portion in a vacuum vessel, wherein the cathode portion is disposed to face the object, and the target is made of a material applied to the object. And a backing plate portion provided on the back side of the target portion and made of the same material as the target portion. 2. The apparatus according to claim 1, wherein the target portion and the backing plate portion are formed integrally.
3. The sputtering apparatus according to 1. 3. The sputtering apparatus according to claim 1, wherein the object is an optical disk substrate.