JPS6335710B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a well-known sputtering apparatus that sputters a target in a vacuum chamber to form a thin film on a substrate with a composition corresponding to the target, and more particularly relates to a sputtering apparatus that sputters a target in a vacuum chamber to form a thin film having a composition corresponding to the target on a substrate. This invention relates to a sputtering device suitable for.

In recent years, research and development has been active in ultra-LSIs, optical communication functional devices, ultra-high density recording devices, etc., and the composition, size, and composition of films made of high melting point or active materials that cannot be fabricated using vacuum evaporation methods are currently being actively researched and developed. There is a strong desire to manufacture films while controlling their properties, and the sputtering method has been reconsidered as a technology that can form films on almost any substrate using any material, and vigorous research and development has been carried out to overcome its drawbacks. ing. And the direction is toward faster speeds and lower temperatures.
There are already many proposals such as the magnetron sputtering method.

By the way, a facing target type sputtering device has been proposed as a sputtering method that can perform high-speed, low-temperature sputtering and can also be applied to magnetic materials ("Oyoi Physics", Vol. 48, No. 6 (1979), pages 558-559). This opposed target sputtering apparatus is constructed as shown in FIG. That is, unlike a conventional bipolar sputtering device in which a substrate and a target are placed facing each other in a vacuum chamber, a pair of targets are placed in a vacuum chamber 10.
Sputtered surface TAs where TA and TB are sputtered,
The TBs are arranged so as to face each other parallel to each other with a space between them, and the substrate 20 is mounted on the target TA by a substrate holder 21 provided on the side of the TB.
It is placed on the side of the TA and TB spaces so as to face the spaces. A coil 30 provided around the vacuum chamber 10 generates a magnetic field H in a direction perpendicular to the sputtering surfaces TAs and TBs. In the figure, 11A and 11B are target holders made of iron, and 12A and 12B are shields for protection.

Therefore, the exhaust port 40 is opened by an exhaust system (not shown).
After evacuating the inside of the vacuum chamber 10 through a gas inlet system (not shown), a sputter gas such as argon is introduced through an inlet 50, and as shown in the figure, a sputter gas such as argon is used as a direct current power source 60 to evacuate the shield 12A,
12B Therefore, sputtering is performed by supplying sputtering power using the vacuum chamber 10 as an anode (grounded) and the targets TA and TB as cathodes, and generating the above-mentioned magnetic field H using the coil 30, and sputtering is performed to form a target on the substrate 20. A thin film with a composition corresponding to TA and TB is formed.

At this time, with the above-mentioned configuration, the sputtered surface TAs,
Since a magnetic field is applied perpendicular to the TBs, high-energy electrons are confined in the space between the opposing targets TA and TB, which promotes ionization of the sputtering gas and increases the sputtering speed, resulting in high-speed film formation. can. Moreover, since the substrate 20 is placed to the side of the targets TA and TB instead of facing the targets as in conventional sputtering equipment,
Collision of high-energy ions and electrons onto the substrate 20 is almost eliminated, and the target
Thermal radiation from TA and TB is also small, resulting in a small rise in substrate temperature, and therefore low-temperature film formation is possible. Furthermore, since the magnetic field is applied as a whole in the perpendicular direction to the targets TA and TB, even if magnetic materials are used for the targets TA and TB, the magnetic field acts effectively and high-speed film formation is possible.

However, in industrial scale mass production, further improvement in productivity is desired, and furthermore, overall efficiency improvement is required. In the above-mentioned conventional facing target sputtering equipment, when the size is increased in order to improve productivity, the coil also becomes larger and equipment costs increase, and in terms of efficiency, the utilization rate of sputtered particles for thin film formation is low. There is.

The present invention has been made in view of the current situation, and utilizes the above-mentioned facing target sputtering method as a basic structure and utilizes its characteristics such as excellent film forming ability, while solving the above-mentioned problems and improving productivity. To provide a sputtering device that is efficient, compact, and suitable for mass production.

That is, in the present invention, opposing targets are provided in a vacuum chamber and are opposed to each other across a target space, and a magnetic field is generated in the space between the targets in a direction perpendicular to the target plane by means of magnetic field generation means arranged behind the targets. , a sputtering device that sputters both targets to form a thin film on a substrate disposed on the side of the space; a support roller that supports a substrate made of a long film and rotates at a predetermined speed; a substrate conveying means for transporting the substrate in close contact with the support roller; and a support roller arranged in a strip shape with a long side in the axial direction, the support roller being disposed along the circumferential surface of the support roller so that the target surface is parallel to the support roller axis. This sputtering apparatus is characterized in that it is equipped with a plurality of sets of opposing targets each consisting of a plurality of targets, and is adapted to continuously form a film while transporting a long film substrate.

Hereinafter, details of the present invention will be explained based on examples and drawings.

FIG. 2 is a schematic side view of an embodiment of the invention.

In the figure, 10 is a vacuum chamber, which is connected to the exhaust system through the exhaust port 40 and to the gas introduction system through the inlet port 50, as in the conventional device shown in FIG. It is now possible to supply the following.

T1 and T2 are the same targets TA1 and T2 in the form of elongated strips facing each other with a predetermined space in between.
Two sets of opposing targets consisting of TB1, TA2, and TB2, and target holders 111, 112, 113, and 114 are fixed to the side wall of the vacuum chamber 10.
As shown in the figure, the long sides (the sides perpendicular to the figure) are parallel to each other and the opposing spaces face each other.

Reference numerals 101, 102, and 103 are transfer rollers that transport the substrate 20 made of a long organic polymer film while facing the opposing space;
1, arranged parallel to the axis of the long side of T2 and on both sides of the opposing space. Note that the transfer roller 102 is commonly used for the opposing targets T1 and T2.

And guide rollers 151, 152, 153,
154, a feeding device 61, and a winding device 62, the substrate 20 is transferred while being in close contact with the transfer rollers 101, 102, and 103 and facing each opposing space.

Therefore, it is possible to realize a highly productive sputtering device with an overall compact configuration.

Note that the transfer rollers 101, 102, and 103 are driven by a control device (not shown) that can adjust the circumferential speed between the transfer rollers 101, 102, and 103 so that the substrate 20 is transferred at a uniform speed. The control device drives the transfer roller 101 at a constant circumferential speed,
A tension detector (not shown) for detecting the tension of the substrate 20 is provided between the guide rollers 151 and 152,
The speed of the transfer roller 102 is adjusted so that the tension remains constant. The speed of transfer roller 103 can be adjusted similarly to transfer roller 102.

It is preferable that the surfaces of the transfer rollers 101, 102, 103 have excellent flatness and excellent adhesion to the substrate 20. Also, transfer rollers 101, 102, 10
It is preferable that the surface temperature of No. 3 can be adjusted from room temperature to several hundred degrees Celsius. The surface temperature can be adjusted by circulating a heating medium such as silicone oil inside the roller.

Target holder 111, 112, 113,
Reference numeral 114 has a cavity structure made of a non-magnetic material, and can be cooled with cooling water or the like through a cooling pipe (not shown).

Also, the magnetic field generating means is replaced with the coil 30 shown in FIG.
Targets TA1 and TB1, TA facing behind
Place the target holders 111, 112, 1 so that the polarities of TB2 and TB2 are in the same direction and the lines of magnetic force are perpendicular to the targets TA1, TB1, TA2, TB2.
Permanent magnets 301, 30 placed in 13, 114
2,303,304. Permanent magnet 30
1, 302, 303, 304 are target holders 111, 11, respectively, as shown in FIG.
2, 113, and 114, a wall of magnetic field is formed along the periphery of the opposing targets T1 and T2 so as to surround the opposing space between them. And as shown, a permanent magnet 30
When the opposing sides of the magnetic field elements 1, 302, 303, and 304 are shaped like cutting edges with tips on the peripheral side, the wall of the magnetic field is limited to the peripheral edge, and the erosion of the target becomes uniform.

In addition, the shield rings 121, 122, 12
3,124 is target holder 1 as before.
11, 112, 113, and 114 as shown in the figure.

In addition, the sputtering power is supplied from the respective power sources (not shown) to the vacuum chamber 10 and the shield rings 121 and 12, which are held at ground potential, as in the conventional device described above.
Anodes 2, 123, and 124 are respectively supplied to opposing targets T1 and T2.

From the above configuration, the vacuum chamber 10
After evacuating the inside, the opposing targets T1 and T2 are sputtered by supplying sputtering power from the power supply while introducing sputtering gas, and a thin film having a composition corresponding to the target material is formed on the substrate 20.

As mentioned above, permanent magnets 301, 302,
Opposing targets T1, T2 by 303, 304
Since a magnetic field wall is formed at the periphery of the substrate 20, high-energy electrons are confined in each opposing space, ionization of the sputtering gas is promoted, and high-speed film formation is possible.
Since it is located on the side of 2, it is possible to form a film at a low temperature. That is, each of the facing targets T1 and T2 functions in the same manner as the conventional facing target type sputtering apparatus shown in FIG. 1, and maintains the excellent characteristics of high-speed and low-temperature film formation.

In addition, the above structure eliminates the need for a coil, resulting in a compact structure, and since the magnetic field wall is formed only around the target, the spatter of the target is less This has the great effect of making the magnetic field uniform over the entire surface and making it easy to form a magnetic field, making it possible to widen the distance between the targets.

By the way, when a film is formed while the substrate 20 is being transferred, particles sputtered by the opposed targets T1 and T2 are deposited and formed on the substrate 20 one after another. Therefore, if each of the facing targets T1 and T2 is composed of target materials of the same composition, the film formation rate will be four times that of the conventional facing target type sputtering device.
Productivity increases significantly. Moreover, since the sputtered particles are used to form a film on both sides of opposing targets T1, T2, the efficiency of target usage is at least twice that of conventional devices. Furthermore, as mentioned above, the targets T1 and T2 are formed into elongated rectangular shapes, and the side surface through which the substrate 20 is transferred is configured to have a wide width. The calculated rate can be increased significantly. This usage efficiency is determined by the width ratio of the long side facing the substrate 20 and the short side of the opposing targets T1 and T2, so if the width ratio is set to 4:1 or more, it becomes 80% or more, which is satisfactory in many cases. Become something.

Note that a shielding plate may be provided on the short side not facing the substrate 20 to capture sputtered particles. That is, the substrate 2 on which the film is formed
Spatter particles other than those flying to the target holder 111, 112, 113, 114 facing
Capture at the outer periphery of. Therefore, the spattered particles do not adhere to the inner wall of the vacuum chamber 10, so that the vacuum chamber can be kept clean at all times. Particularly in the case of a large sputtering device, cleaning during film formation becomes easy, and productivity and maintainability can be improved.

Further, great effects can be obtained when multilayer films are sequentially formed on the substrate 20 as described below. for example,
When manufacturing the perpendicular magnetic recording media disclosed in Japanese Patent Application Laid-open No. 54-51804, Japanese Patent Application Laid-Open No. 57-100627, etc., permalloy is used as the opposing target T1, cobalt chromium alloy target is used as the opposing target T2, and the substrate 20 is
By fabricating the film while transferring the substrate 2
In other words, a desired perpendicular magnetic recording medium having a permalloy soft magnetic film and a cobalt chromium perpendicularly magnetized film on a polymer film can be continuously produced. By the way, the surface flatness of the substrate 20 is important for perpendicular magnetic recording media, and the surface flatness of the substrate 20 is important when the substrate 20 is transferred.
If scratches or irregularities occur that impair the surface flatness of the recording medium, its value as a recording medium will be halved.
However, according to this configuration, the substrate 20 is transferred without slipping while strictly adjusting the transfer speed by the transfer rollers 101, 102, 103, and 104, and the two-layer film is formed on the substrate 20 only once. This can be achieved with 20 transfers. Therefore, substrate 2
The probability of occurrence of factors that impair the surface flatness of 0 can be drastically reduced.

Although the present invention has been described above based on Examples, the present invention is not limited to such Examples.

Although two pairs of opposing targets are shown as a suitable example for forming a two-layer film, the number of opposing targets should be designed as appropriate depending on the purpose of use and is arbitrary. Note that when a large number of sets, for example, four sets of opposing targets are provided, a multi-stage arrangement is also possible in which two sets are arranged side by side in two stages, one above the other, as in the embodiment. In this way, the installation space in the row direction can be greatly saved.

In the case of the above-mentioned four sets of opposing targets, if they are arranged in orthogonal coordinates as shown in FIG. 3, the number of transfer rollers can be greatly reduced and the overall structure can be made compact. FIG. 3 is a side sectional view from the short side of the target. Therefore, the orthogonal coordinate arrangement means that the center line of the short side of the opposing targets T ₁ to _{T 4} is aligned with each of the orthogonal coordinate axes, as shown in the figure. It is an arrangement that looks like it is on an edge. When forming a film while transporting the substrate 20 in the direction shown by the solid arrow along the route shown by the solid line according to the arrangement shown in the figure, the substrate 20 can be transferred in one run.
Multilayer films of up to three layers can be formed on both sides of 0. Note that by configuring all targets with the same composition, a single layer film can be formed at high speed. A single layer film can be formed on one side of the substrate 20 at a very high speed by transporting it in the direction of the dotted arrow along the path partially indicated by the dotted line in the figure.

In addition, in the one in Fig. 3, targets TB1, TB2, TB3, and TB4 on the origin side of the orthogonal coordinate arrangement are mounted on independent target holders 1 for easy control.
12, 114, 116, and 118,
If these target holders are used in common, there is an advantage of a compact configuration.

Note that the other configurations in FIG. 3 are the same as those in FIG. 2, and the explanation thereof will be omitted. Further, the symbols in FIG. 3 are the same as in FIG. 2. Further, although the feeding device and the winding device for the substrate 20 are provided in the same room as the target, they may be separated into the feeding chamber, sputtering chamber, and winding chamber through an opening/closing means. in this case,
Since the sputtering chamber can be separated and kept under vacuum if necessary, productivity can be expected to improve.

As described above, in the present invention, targets in the form of elongated strips are used as opposing targets, and transfer rollers are arranged on both sides of the long sides of the targets. Since the film is formed while the molecular film is being transported, a sputtering apparatus has been realized which has a very compact structure, has a high target usage efficiency, and does not damage the substrate. As described above, the present invention makes a significant contribution to improving the productivity of sputtering equipment, particularly sputtering equipment of the opposed target type.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the structure of a conventional device, FIG. 2 is a schematic side sectional view showing the structure of an embodiment of the present invention, and FIG. 3 is a schematic side sectional view showing the structure of another embodiment of the present invention. It is. 10: Vacuum chamber, 20: Substrate, TA to TB4: Target, 101 to 104: Transfer roller, 11
A, 11B, 111-118: Target holder, 12A, 12B, 121-128: Shield ring, 151-162: Guide roller, 301-
308: Magnet.

Claims (1)

[Scope of Claims] 1 Opposing targets are provided in a vacuum chamber and are opposed to each other with a space between them, and a magnetic field in a direction perpendicular to the target plane is generated in the space between the targets by a magnetic field generating means arranged behind the targets. In a sputtering device that forms a thin film on a substrate disposed on the sides of the space by sputtering both targets, a support roller rotates at a predetermined speed while supporting a substrate made of a long film. a substrate conveying means for transporting the substrate in close contact with the support roller; and a support roller disposed along the circumferential surface of the support roller such that the target surface is parallel to the support roller axis. and a plurality of sets of opposing targets consisting of strip-shaped targets,
A sputtering apparatus characterized in that a film is continuously formed while transporting a long film substrate. 2. The sputtering apparatus according to claim 1, wherein the support roller is also provided on the other long side of the plurality of opposing targets. 3. Claim 2, wherein the support roller and the plurality of opposing targets are arranged alternately in a row.
The sputtering device described in Section 1. 4. A patent in which the opposing targets are arranged so that the center line of the cross section on the short side is on each side of the orthogonal coordinates, and the supporting roller is provided common to each opposing target adjacent to each quadrant of the orthogonal coordinates. A sputtering device according to claim 1. 5. The sputtering apparatus according to claim 4, wherein the targets on the origin side of the orthogonal coordinates of each set of opposing targets are provided on a common target holder.