JPS5922932A - Preparation of thin film - Google Patents

Abstract

PURPOSE:To obtain a thin film of high quality having a flexible film as a substrate at a low cost, by adhering a flexible film closely to a beltlike member, winding up the resultant laminated member, forming a thin film on the surface of the flexible film under reduced pressure while transferring them. CONSTITUTION:A flexible film 1 is closely adhered to a beltlike member 2 consisting of a metal or plastic, etc., and the resultant laminated member 3 is then wound into a roll 4. The laminated member 3 is then withdrawn and introduced into a vessel 7 having a means for forming a thin film, e.g. the sputtering or vapor depositing method, etc., and a material, e.g. Co, Fe or Si, capable of exhibiting the function is deposited on one side of the flexible film 1 while sliding the laminated member 3 on a hot plate 9 at a controlled temperature under reduced pressure to form the aimed thin film. EFFECT:The temperature control of the film can be carried out with certainty without applying an excess tension to the flexible film 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of thin films under vacuum such as sputtering, X9 evaporation, ion plating, etc. .

Magnetic thin films such as Co * Fe + N1 are formed to manufacture magnetic recording media, vapor deposited thin films such as St are formed to manufacture solar cells, or transparent conductive thin films such as In are formed. This invention relates to a method for producing a thin film suitable for producing transparent conductive films, etc. 5 Thin films with specific functions such as the upper side under vacuum The technology for creating functional thin films, in other words, has made remarkable progress in the semiconductor industry in recent years.
Devices are also becoming larger and faster, but these techniques are limited to applications where substrates have high rigidity, such as silicon plates, glass plates, or stainless steel plates, and the substrate dimensions are relatively small. Plastic films are attracting attention as substrates that can be used to provide functional thin films at low cost, but such films have low planar rigidity, that is, they are flexible, and cannot be used as substrates with high rigidity, that is, hard substrates, as described above. Applying the thin film production technique of 2008 directly causes various problems as described below.

First, in the case of the 1st K hard substrate, since the substrate size is generally small, the substrate is moved with the substrate attached to a separate conveyance means, and the load applied to the substrate K is virtually zero, and the substrate is moved by a separate conveyance means. Movement is often intermittent due to the use of However, when a flexible film is used as a substrate, the film itself (σ) serves as a conveying means, and a method is usually adopted in which tension is applied to the film itself, and furthermore, the 6 ridges due to self-gK are Fillem itself generates VC. If the tension is applied too much, wrinkles will appear in the flexible film, and if the tension is too low, the adhesion of the flexible film to the supporting member will deteriorate, leading to problems such as warm unevenness, which will be discussed later. However, the elasticity of the film is generally low, and if a large tension is applied during film formation, in other words, when depositing a functional thin material, the material will be compressed as a result. There are many cases in which stress is applied and the function of the functional material cannot be effectively demonstrated.

Second, flexible films generally have low heat resistance and poor thermal conductivity, so uneven heating and cooling due to heat conduction from the support plate is exacerbated, resulting in uneven temperature distribution of the flexible film. It tends to become uniform, and furthermore, the strength at high temperatures is extremely reduced due to lack of heat resistance, and local unevenness in width easily causes problems of melting and heat shrinkage of the flexible film. There is no such problem with hard substrates, and this is a problem specific to thin film forming techniques using flexible raw films as substrates.

Thirdly, flexible films are generally very thin, ranging from several μm to several 100 μm, and abnormalities may be caused by the surface irregularities of the cylindrical support or planar support that supports the film, or by direct transfer of foreign matter adhering to the surface of the film. This is likely to occur, especially when the flexible film and support plate are closely layered and there is no relative speed.

Historically, the industrial advantages of using a flexible film as a substrate include the continuity of its conveyance, the thinness of the substrate, which makes it easy to handle per area, and the volume is low. The problem lies in the fit, but even the slightest contamination of the film can lead to a large yield and low TVC, and great care must be taken to prevent contamination not only during the deposition of the functional material but also before and after the deposition.

Considering the above points, [as a means of forming a functional thin film on a flexible film, a flexible film is traditionally stamped on a cylindrical support and the cylindrical support and flexible film are closely attached. A method of fixing the material so as not to cause a relative rise has been used, and has achieved some success in vapor deposition, magnetron sputtering, etc. However, when using a cylindrical support, what is the film running speed of the cylindrical support? Because of the need to rotate the rc in unison, a dense rotary support member or a high-grade shaft seal member is required, and the device inevitably becomes larger, more complicated, and more expensive. Furthermore, because the film and cylindrical support are closely layered and there is no relative rise, even if local heat shrinkage occurs in the area where the material exhibiting one function is deposited, the film and cylindrical support surfaces are under high vacuum, so there is considerable adhesion. However, it has the disadvantage that it cannot be shrunk as a whole and is deposited under excessive tension, making it unsuitable when delicate tension control is required. Generally, a cylindrical support σ) is wrapped with a film around the entire circumference, and the tension on the film when entering or exiting the cylindrical support is considerably different from the tension on the film at the deposition site. There is. By the way, if the coefficient of static friction between the surface of the cylindrical support and the film is μ, the contact angle θ (rad) + the tension of the crowd is T+ and Tt (Tl>Tt), respectively, then T when there is no local thermal contraction or adhesion. %=T
, e "θ, /7=0.2. θ= w
A fairly large tension change of ~1,5rT+/Tt=1°9-2.6 occurs on the same side of the cylindrical support.

Even when there is local heat shrinkage and the film does not move relative to each other due to adhesion, the tension caused by heat shrinkage is T.
TI=T6e〃0', T2=To6'θ2(θ
1+θ,=0), there are even cases where a tension change in the opposite direction is observed.

Vapor deposition, magnetron sputtering, etc. do not require precise tension control, and the temperature at which a geometric thin film is deposited on a flexible film is generally lower than the melting point or softening point of the flexible film, so Although the drawbacks of the cylindrical support plate have not become apparent, when higher temperature function or faster and more stable formation speed is required, the most important method when depositing a functional material on a flexible film is (1) The flexible film should not wrinkle due to tension, thermal contraction, etc. (21 Kinetic energy of atoms coming to the film).

Overcoming the radiant energy of the plasma, the temperature of the flexible film is within the target range (controlled and no local thermal shrinkage, melting, or breakage occurs); (3) The flexible film and the The purpose of this invention is to prevent deposits on the surface from imparting excessive residual strain, thereby allowing the functional material to effectively perform its functions. The present invention was arrived at as a result of intensive research into ways to reliably control the temperature of the film without imparting excessive tension to the film by reducing tension changes originating from the corners. When forming a functional thin film on a flexible film that moves continuously under vacuum, the flexible film and the band-like member are simultaneously wound using a roll in which the flexible film and the band-like member are wound up in alternating layers. The method is characterized in that the flexible film and the band-shaped member are brought into substantially close contact with each other and are run at the same speed to form a film. The purpose of the present invention is to provide a functional thin film using a functional film as a substrate.

The state in which the flexible film and the strip member are in substantially close contact with each other means a state in which effective heat transfer can be achieved between the flexible film and the strip member, and more specifically, the following configuration is used. is cheered.

(11 The flexible film and the band-shaped member are adhered or adhered to each other with an adhesive, an adhesive, etc., and are in a laminated state.

(21 The flexible film and the band-shaped member are pressed by a pressing roller or the like, and are brought into close contact with each other in a laminated state.

(3) The surface pressure (kQf/rrl) between the flexible film and the strip member is equal to or greater than o, ox kyf/m'.

Cases etc. Special 1/C@3rd example is that when the thickness of the flexible film is extremely small, when the flexible film is placed on the strip member, the surface pressure of the flexible film alone is insufficient. was not obtained, and the band-shaped member vertically downward,
When the flexible film is placed in the + There is. A specific example of the surface pressure applying means will be described later.

The strip member used in the present invention has a width equal to or greater than the width of the flexible film, and is preferably made of metal, plastic kick, or rubber (including reinforcing fibers), and has a thickness of any size. The flexible film can be selected depending on the purpose as long as it does not cause any trouble in handling, but the preferred range is 10 to 300μ for metal, and 10 to 300μ for plastic. θ~100
In the case of rubber, it is 0.5 to 2n. It goes without saying that the band-shaped member may be made of not only a single material, but also a combination of the above-mentioned materials, and in this case, the thickness of the band-like material is preferably TIK thinner than the above-mentioned preferred value.

The present invention will be described in more detail below with reference to the drawings, but the drawings merely show the configuration of the invention more specifically and do not limit the invention.

Fig. 1 shows an outline of an apparatus using the present invention for forming a functional thin film on a flexible film by facing target sputtering method, and Fig. 2 shows an outline of an apparatus using the present invention to form a functional thin film on a flexible film by the facing target sputtering method. FIG. 2 is a schematic diagram enlarged in the thickness direction of a plastic film and a strip-shaped member.

As shown in FIG. 2, a flexible film 1 and a strip member 2
The laminated members 3 are pressed by a pressure roller and brought into close contact with each other, and then wound onto a bobbin to form a roll 4 and installed in an unwinding chamber 5. In FIG. After passing through the delivery roll 6, the roll was placed in a container 7 and slid on a hot plate 9 whose surface 8 was controlled at a constant temperature and pressure, and the take-up re-roll 10 was quietly placed in the take-up chamber 11. Winding pobbin 32Vc is wound. Exhaust systems 13, 14 and 15 are connected to the unwinding chamber 5 and winding chamber 11 of the container 70, respectively, thereby maintaining the entire area through which the laminated member 3 passes under a high vacuum.

In the container 7, targets 16a, 16b are installed facing the flexible film 1@, and the targets 16a, 16
The BIC is a facing target type sputtering device that is equipped with a magnet (not shown) and has a structure in which a magnetic field is generated between the targets. Therefore.

"Applied Physics J @ 4s Vol. 6 P557-pli64゜ 5. Container 7.
Atmospheric gas (e.g. argon gas) is introduced into the container 7 through the gas introduction means 17 leading to the
If an excessive power source 18 is connected between the targets 1fla and 16b and the container 7, a glow discharge occurs between the targets 1fla and 16b, and the atmospheric gas enters the t# state and becomes plasma.

At this time, the ionized atmospheric gas collides with Targera),
Atoms on the target surface are ejected (sputtering phenomenon), and the sputtered atoms reach the flexible film IK moving laterally with a certain kinetic energy and are sequentially deposited on the film to form a thin film. The laminated member 3 is connected to the bobbin 4 with a torque adjustment device (
The winding bobbin j21c is sequentially wound at a constant speed by a speed adjusting device (not shown) K provided in a drive device connected to the winding bobbin 12 while the tension is controlled by a winding bobbin j21c (not shown).

The hot plate 9 communicates with a heating/cooling device ff119 via conduits 20.21, and is controlled so that the temperature of the surface 8 is constant. In the case of only heating, it is convenient to embed an electric heater in the hot plate 9.

By the way, the laminated member 3. Ultimately, the temperature of the flexible film 1 depends on the amount of heat transfer that takes place through the microscopic contact surface between the strip member 2 and the surface 8 of the hot plate 9, and the size of this contact surface, i.e. The contact area is determined by the zero surface pressure on the contact surface, surface roughness and surface hardness (generally represented by elastic modulus), and is particularly influenced by blood pressure. Therefore, as shown in FIG. 2, the flexible film 1 is positioned above the hot plate 9, that is, the functional material σ) is deposited in the upward direction, and as shown in FIG. 9, that is, when the stacking direction of the functional material is downward, the direction of the effect of the own weight of the laminated member 3 on the blood pressure force is opposite, and the second
In the case shown in the figure, when the surface 8 of the hot plate 9 is flat, the tension σ) acting on the laminated member 3 is σ), regardless of its size, the surface pressure between the strip member 2 and the surface 80 is guaranteed to be the lowest intraocular weight. But the third
In the case shown in the figure, there is a possibility that the strip member 2 will separate from the surface 8 of the hot plate 90 due to the weight of the laminated member 3. Therefore, if the surface 8 of the hot plate 90 is flat, no matter how much tension is raised, the distance between the surface 8 and the strip member 2 will increase. Adhesion is not guaranteed, and in order to guarantee adhesion, it is necessary to give the inner surface 8 of the hot plate 90 a curvature as shown in the figure, and the radius of curvature R needs to be less than or equal to Rm determined by the following formula. There is.

Rm = T6 / r Here, Rm is the maximum allowable radius of curvature (cm) of the hot plate 9, and r is the weight t per unit area of the laminated member 30 when the functional material is deposited on the flexible film l. (kgf/crI)
, To is the minimum tension (ktif/ext) of the laminated member 3 on the hot plate 9 per unit.

The downward deposition direction as shown in FIG. 3 is a more preferable form with less contamination on the flexible film l, but
Particular attention is required.

The present invention has a structure in which there is no relative slip between the flexible film 1 and the strip-like member 2 (and they are in close contact with each other), so it has various advantages described below.

First of all, since only the first & C strip member 2 contacts the fixing member such as the hot plate 9 and the flexible film l itself does not come into contact with any fixing member, it is natural that the back gI4 of the flexible film In other words, it is possible to completely eliminate so-called scratches such as scratches and streaks on the contact surface with the strip member 2.
After a series of treatments are completed, simply by removing the strip member 2 and rolling up the flexible film 1, a scratch-free thin film material with high commercial value can be obtained. Historically, it has been possible to easily obtain a high value-added functional thin film with no scratches on both sides of the flexible film by bringing the strip member 2 into close contact with the functional material deposited again and depositing the functional material on the back side. It will be done. Further, since it has a relative speed with respect to a fixed member such as the hot plate 9, there is an advantage that abnormalities or sights on the surface of the hot plate 90 are not transferred to the flexible film IK.

Second, the material/property of the flexible film 1 (am) fx <the strip member 20, the quality or surface roughness of which can be selected as appropriate;
It is possible to easily slide on fixed members such as the like, thereby reducing frictional force, and reducing changes in tension during processing of the laminated member 3. Furthermore, since the thickness of the band-shaped member 2 is arbitrarily set, the tension borne by the flexible film 1 can be reduced by increasing the thickness of the band-shaped member 2, or if the tension of the flexible film 1 is the same, the winding It has the advantage of being able to take a large tension and improving the control accuracy of the device.

Thirdly, when metal is used for the band member 2, the thermal conductivity of the metal is good, so the heat transfer limit from the hot plate 9 etc. is increased, and the thermal gradient within the band member 2 is reduced. As a result, the temperature uniformity of the flexible film 1 is also improved.

Furthermore, unlike in the case of a cylindrical support, the function-producing element stack does not rotate, making the installation itself inexpensive. A can only be achieved 1.
However, by making the strip member 2 stiff and rigid, even if foreign matter adheres to the hot plate 9 or the surface is uneven, these will remain flexible films. : It has the advantage of not being transferred.

Figure 4 shows an example in which cooling or heating is performed by radiation from the open side of the strip, in which the container 0 is kept in a vacuum, the unwinding chamber 1 is
The same parts as in FIG. 1, such as the winding chamber, exhaust system, and plasma generation power source, are not shown.

In the figure, the laminated member 3 is spatially positioned by a delivery roll 40 and a take-up roll 43, and is traveling at a distance dl from the cooling plate 41 + a distance d from the heating means 42a and 42b. Functional material is opposing Y-Get 44
The laminated member 80 is sputtered and deposited on the flexible film 1, but the amount of heat transferred from the flexible film l to the strip member 2 side depends on the distance d between the strip member 2 and the cooling plate 41, and the temperature of the cooling plate 41. Therefore, the temperature of the flexible film 1 is controlled by appropriately selecting the above-mentioned values so as to balance the heat transfer Jt'Af with the amount of heat input to the flexible film 1. Heating means 42a provided after the functional material is deposited
, 42b and the distance 1l11 dt are provided for heat treatment of the flexible film 1 with the functional thin film. In such cases, heat transfer is greatly influenced by the emissivity or absorption rate of the strip member 2, but according to the present invention, the surface treatment or material of the strip member 2 can be adjusted to have a desired emissivity or absorption rate. It has the advantage of being selective.

When the band-shaped member 2 is made of metal, it has good thermal conductivity, which improves the uniformity of the temperature of the flexible film 1, and also has the advantage of increasing the winding tension.

In the above example, a configuration is shown in which the flexible film l and the strip member 2 are wound together. A method of winding only film 1 is also available. Also, in figure g1, it is the unwinding chamber.

Although both the winding chambers are kept under vacuum,
If known means are used to disconnect between the atmosphere and vacuum, the unwinding chamber 9
Of course, the winding chamber may be placed in the atmosphere. Furthermore, while the thin film forming method has been explained using opposed target sputtering as an example, it is of course possible to apply it to other sputtering methods, 1XX fumigation method, ion erasure method, and other methods of depositing or etching a functional material. , it can also be applied to thin film forming means combining these methods.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an embodiment of an apparatus using the present invention for facing target sputtering, and Figs. Figure 4 shows a schematic diagram of the main parts of a device for forming a five-functional thin film using radiation heating and cooling using the present invention. J: Flexible film, 2: Strip-like member. 4: Roll, 9: Hot plate. 16g, 16b, 44a, 44b: Target 21 figure Z figure

Claims (1)

[Claims] (1) When forming a thin film on a flexible film that moves continuously under vacuum, the flexible film and the strip-shaped member are simultaneously rolled up by a roll in which the flexible film and the strip-shaped member are wound up in alternating layers. A method for producing a functional thin film, the special mission of which is to unwind the flexible film and the band-shaped member and run them at the same speed while bringing them into substantially close contact with each other to form the film.