WO2016194696A1

WO2016194696A1 - Sputtering target and sputtering deposition method using same

Info

Publication number: WO2016194696A1
Application number: PCT/JP2016/065249
Authority: WO
Inventors: 寛人渡邉
Original assignee: 住友金属鉱山株式会社
Priority date: 2015-05-29
Filing date: 2016-05-24
Publication date: 2016-12-08
Also published as: KR20180014007A; JP2016222975A; JP6716863B2; TW201641729A; TWI689608B; CN107614746A; CN107614746B

Abstract

Provided is a sputtering target capable of reducing generation of particles resulting from abnormal discharge and arcing. This sputtering target is used for magnetron sputtering, and a plate-like member is detachably fitted in a non-erosion region located at the central portion of a target surface of the sputtering target. When the sputtering target is fitted in, the surface of the plate-like member on the target surface side is preferably almost flush with the target surface before the sputtering target is eroded or is preferably disposed at a position recessed from the target surface.

Description

Sputtering target and sputtering film forming method using the same

The present invention relates to a target used for magnetron sputtering in which sputtering is performed by forming a magnetic field on the surface of the target, and a sputtering film forming method using the target.

For flat panel displays (FPD) installed in mobile phones, portable electronic document devices, vending machines, car navigation systems, etc., the adoption of “touch panels” that allow input by bringing the tip of a finger or pen into contact with the display screen has become widespread is doing. “Touch panel” can be broadly divided into “resistance type” and “capacitance type”, and “resistance type” touch panel is for detecting X coordinate (or Y coordinate) formed on a transparent substrate made of resin film. And an electrode sheet for Y-coordinate (or X-coordinate) detection formed on a glass substrate with an insulator spacer interposed therebetween so that both electrode sheets face each other. Yes. And by pressing with a pen etc. from the surface of a transparent substrate according to a screen display, both electrode sheets will contact electrically, and, thereby, the X coordinate and Y coordinate of the said press position can be detected now.

On the other hand, the “capacitance-type touch panel” is a laminated body composed of an electrode sheet for X-coordinate (or Y-coordinate) detection and an electrode sheet for Y-coordinate (or X-coordinate) detection that face each other across an insulating sheet. It has a structure in which an insulator such as glass is arranged on the top, and when a finger is brought close to the surface of the insulator according to the screen display, the capacitance of the X coordinate detection electrode and the Y coordinate detection electrode in the vicinity changes. Therefore, the X coordinate and Y coordinate of the position of the finger can be detected. Both the above-mentioned “resistive type” and “capacitance type” touch panels can recognize coordinates each time a pen or the like is moved. Yes.

As the conductive material constituting the electrode sheet, a transparent conductive film such as ITO (indium oxide-tin oxide) has been widely used as described in Patent Document 1. This transparent conductive film has the advantage that almost no circuit pattern such as an electrode is visually recognized because of its excellent transparency in the visible wavelength region. However, since the electrical resistance value is higher than that of a thin metal wire, the touch panel is enlarged and the response speed is high. It has a disadvantage that is not suitable for conversion.

Therefore, as disclosed in Patent Document 2 and Patent Document 3 and the like, a metal thin wire (metal film) having a mesh structure suitable for increasing the size of a touch panel and increasing the response speed due to its low electric resistance value has recently been developed. It has begun to be used as the touch panel becomes larger. However, since metal thin wires (metal films) have high reflectivity in the visible wavelength region, even if they are processed into a fine mesh structure, circuit patterns may be visible under high-intensity illumination, reducing product value. Have the disadvantages.

In order to make use of the characteristics of a metal fine wire (metal film) having a low electric resistance by reducing the high reflectance of the metal fine wire (metal film) visually recognized from the transparent substrate side, it is described in Patent Document 4 or Patent Document 5. As described above, a technique has been proposed in which a reactive sputtering film formation layer (also referred to as a blackening film) made of a metal oxide is interposed between a transparent substrate made of a resin film and a thin metal wire (metal film). Yes.

JP 2003-151358 A JP 2011-018194 A JP 2013-0669261 A JP 2014-142462 A JP 2013-225276 A

The reactive sputtering film-forming layer made of metal oxide is usually reactive sputtering using a metal target (metal material) in a reactive gas atmosphere containing oxygen from the viewpoint of improving the film-forming efficiency of the metal oxide. Thus, continuous film formation is performed on the surface of the long resin film. And the laminated film used for preparation of an electrode substrate film by forming a metal layer continuously on this reactive sputtering film-forming layer by sputtering etc. using metal targets (metal materials), such as copper further Is being made.

However, when reactive sputtering with a reactive gas containing oxygen is performed for a long time, an insulating film (oxide film) deposited in a non-erosion region on the target surface of the metal target causes arcing, and particles generated by this arcing are generated. When forming a circuit pattern such as an electrode by adhering to the surface of a long resin film, a disconnection failure or a short failure may occur. Further, when the amount of the insulating film deposited in the non-erosion region increases, the insulating film easily peels off, and abnormal insulation may occur when the peeled insulating film enters the discharge space. If particles generated by this abnormal discharge also adhere to the surface of the long resin film, it may cause disconnection failure or short circuit failure when forming a circuit pattern such as an electrode. The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a sputtering target capable of reducing generation of particles due to arcing or abnormal discharge.

The inventor forms a groove in the non-erosion region located in the center of the target surface of the metal target, and periodically replaces the plate-like member detachably fitted in the groove to insulate the non-erosion region. The amount of deposited film can be suppressed to a certain amount or less, and it has been found that the amount of particles adhering to the surface of a long resin film can be reduced by suppressing the occurrence of arcing and abnormal discharge, and the present invention is completed. It came to do. That is, the sputtering target provided by the present invention is a sputtering target used for magnetron sputtering, and a plate-like member is detachably fitted in a non-erosion region at the center of the target surface of the sputtering target. It is characterized by.

According to the present invention, it is possible to easily remove particle deposits caused by reactive sputtering film deposition attached to the non-erosion region at the center of the target surface of the sputtering target. Thereby, when forming a reactive sputtering film | membrane on the surface of a resin film, it can prevent that defects, such as a defect by abnormal discharge resulting from the said particle deposit, and adhesion of a particle, arise.

It is a typical front view of the film-forming apparatus using the magnetron sputtering cathode provided with the sputtering target of this invention. It is a longitudinal cross-sectional view of the magnetron sputtering cathode provided with the sputtering target of one specific example of this invention. It is a perspective view of one specific example of the sputtering target of this invention. It is a typical schematic sectional drawing of the 1st laminated body film which can be produced with the film-forming apparatus using the magnetron sputtering cathode provided with the sputtering target of this invention. It is a typical schematic sectional view of the example of a change of the 1st laminated body film which can be produced with the film-forming apparatus using the magnetron sputtering cathode provided with the sputtering target of the present invention. It is a typical schematic sectional drawing of the 2nd laminated body film which can be produced with the film-forming apparatus using the magnetron sputtering cathode provided with the sputtering target of this invention. It is a typical schematic sectional drawing of the electrode substrate film obtained by patterning the 2nd laminated body film produced with the film-forming apparatus using the magnetron sputtering cathode provided with the sputtering target of this invention.

First, as a specific example of a film forming apparatus using a magnetron sputtering cathode provided with the sputtering target of the present invention, a sputtering web coater 10 capable of continuous film formation by a reactive sputtering method as shown in FIG. 1 will be described. The sputtering web coater 10 shown in FIG. 1 is preferably used when a film forming process is continuously and efficiently performed on the surface of the long resin film F conveyed in a vacuum chamber 11 by a roll-to-roll method.

More specifically, the vacuum chamber 11 incorporates various vacuum devices (not shown) such as a dry pump, a turbo molecular pump, and a cryocoil. After the pressure inside 11 is reduced to an ultimate pressure of about 10 ⁻⁴ Pa, the pressure can be adjusted to about 0.1 to 10 Pa by introducing a sputtering gas. A known gas such as argon is used as the sputtering gas, and a gas such as oxygen is further added depending on the purpose. The shape and material of the vacuum chamber 11 are not particularly limited as long as they can withstand such a reduced pressure state, and various types can be used.

In this vacuum chamber 11, the unwinding roll 12 and the winding roll 24 which respectively unwind and wind the long resin film F conveyed by roll-to-roll, and the various which demarcate the conveyance path | route of this roll-to-roll Roll groups are arranged. Among the above-mentioned various roll groups, the can roll 16 located substantially in the center of the roll-to-roll conveyance path is driven to rotate by a motor and circulates a coolant whose temperature is controlled outside the vacuum chamber 11 inside. As a result, the long resin film F to be subjected to a film forming process with a heat load can be wound around the outer peripheral surface and cooled. The space where the can roll 16 is provided is separated from the space where a roll group other than the can roll 16 is provided by the partition plate 11a.

The roll group that defines the transport path from the unwinding roll 12 to the can roll 16 includes a free roll 13 that guides the long resin film F, a tension sensor roll 14 that measures the tension of the long resin film F, and a motor. The pre-drive feed roll 15 is arranged in this order. Similarly to the above, the roll group that demarcates the conveyance path from the can roll 16 to the take-up roll 24 is a motor driven post feed roll 21 that adjusts the peripheral speed of the can roll 16 and the tension of the long resin film F. The tension sensor roll 22 that performs the measurement and the free roll 23 that guides the long resin film F are arranged in this order.

The long resin film F is unwound from the unwinding roll 12 and taken up by the take-up roll 24 by the rotation of the can roll 16 and the front feed roll 15 and the rear feed roll 21 that rotate in conjunction with the rotation. It has become. At that time, the tension balance of the long resin film F is maintained by torque control using a powder clutch or the like of the unwinding roll 12 and the winding roll 24. Further, the peripheral speeds of the front feed roll 15 and the rear feed roll 21 can be adjusted with respect to the peripheral speed of the can roll 16, whereby the long resin film F is adhered to the outer peripheral surface of the can roll 16. It becomes possible to make it.

At a position facing the outer peripheral surface of the can roll 16, along a conveyance path defined on the outer peripheral surface of the can roll 16 (that is, an area in which the long resin film F is wound around the outer peripheral surface of the can roll 16). Magnetron sputtering cathodes 17, 18, 19 and 20 as film forming means are provided in this order. Each of these magnetron sputtering cathodes 17 to 20 has

gas release pipes

25, 26, 27, 28, 29, 30, 31, which discharge reactive gas, to the front part and the rear part in the conveying direction of the long resin film F. 32 is installed.

Next, the

magnetron sputtering cathodes

17, 18, 19 and 20 will be described in detail with reference to the longitudinal sectional view of FIG. The magnetron sputtering cathode 40 shown in FIG. 2 has a structure in which a magnetic circuit 42 is housed in a housing 41 including a substantially rectangular parallelepiped housing 41a and a rectangular housing cover 41b covering the opening. The magnetic circuit 42 includes a magnet 42a and a yoke 42b that supports the magnet 42a from the back side. The housing cover 41 b has a cooling plate 43 superimposed on a surface opposite to the surface facing the magnetic circuit 42. A cooling water passage 44 through which a coolant such as cooling water passes is formed on the surface of the housing cover 41b that faces the cooling plate 43. The housing 41a and the housing cover 41b, and the housing cover 41b and the cooling plate 43 are sealed with a sealing material such as an O-ring.

In this cooling plate 43, the sputtering target 45 of one specific example of the present invention is provided on the surface opposite to the surface facing the housing cover 41b. The periphery of the sputtering target 45 is provided with a step, and the sputtering target 45 is fixed to the cooling plate 43 by a clamp 46 that engages with the step. Except for the target surface of the sputtering target 45, an earth shield 47 is provided so as to wrap all of the sputtering target 45, the casing 41, the cooling plate 43, and the clamp 46, and the bottom of the housing 41 a is interposed via an insulating plate 48. The lever is fixed to the ground shield 47. That is, the housing 41 and the sputtering target 45 that store the magnetic circuit 42 are electrically insulated from the earth shield 47.

As described above, the magnetron sputtering cathode 40 having such a structure is disposed in the vacuum chamber 11 with the target surface of the sputtering target 45 facing the long resin film F that is a film formation target. At the time of sputtering film formation, the vacuum chamber 11 is evacuated and then Ar gas is introduced as a process gas. When a voltage is applied to the sputtering target 45 in this state, the Ar gas is ionized by electrons emitted from the sputtering target 45, and the ionized Ar gas collides with the target surface of the sputtering target 45 to knock out the target material. A thin film is formed by depositing the target material on the surface of the long resin film F, which is a film formation target.

At that time, a poloidal magnetic field is generated on the target surface side of the sputtering target 45, and a voltage of minus several hundred volts is normally applied to the sputtering target 45, while the ground shield 47 in the peripheral portion is kept at the ground potential. Due to this potential difference, an orthogonal electromagnetic field is generated on the target surface side of the sputtering target 45. Secondary electrons emitted from the target surface of the sputtering target 45 move while drawing a cycloid orbit in a direction perpendicular to the orthogonal electromagnetic field on the target surface of the sputtering target 45. During this time, electrons that have collided with Ar gas and have lost a part of their energy make a trochoidal motion in the orthogonal electromagnetic field and drift and move in the poloidal magnetic field.

During this time, the electrons collide with Ar gas again, and as shown by Ar + e ⁻ → Ar ⁺ + 2e ⁻ , Ar ions and electrons are generated by the α action. The produced Ar ions are rapidly accelerated toward the negatively applied sputtering target 45 when diffused into the sheath region. When Ar ions having a kinetic energy of several hundreds of eV collide with the sputtering target 45, the target surface is sputtered to emit sputtered particles and emit secondary electrons by γ action. When the above phenomenon occurs in an avalanche state, plasma is maintained.

Electrons that move while drawing a trochoidal orbit by a magnetic circuit and an electric field in the sputtering cathode 40 are concentrated at a portion where the magnetic lines of force are parallel to the target surface of the sputtering target 45, that is, a portion where the magnetic lines of force and the electric field are orthogonal. The collision of electrons and Ar gas frequently occurs due to the concentration of electrons, so that the target material is knocked out by the ionized Ar gas. As a result, as shown in FIG. 2, erosion (erosion) occurs in a region excluding the central portion and the outer peripheral portion of the target surface of the sputtering target 45, and the central portion and the outer peripheral portion of the target surface become non-erosion regions.

In the case of the above-described sputtering film formation, the knocked-out target material coats the long resin film F, which is the film formation object, and also adheres to the non-erosion region of the sputtering target 45, and the particle deposit A and Become. In particular, in reactive sputtering in which sputtering film formation is performed while supplying a reactive gas such as oxygen gas or nitrogen gas in the sputtering film formation atmosphere, the particle deposit A is oxidized by a substance constituting the target by the reactive gas. Since it becomes an oxide or a nitride, it is deposited in the form of a deposit that is not easily eroded by Ar ions generated by plasma. The particle deposit A thus deposited peels off from the sputtering target 45 during the sputtering film formation, adheres to the long resin film F that is the film formation object, or causes arc discharge. When particles generated by arcing or abnormal discharge adhere to the long resin film F, a disconnection failure or a short failure occurs when a circuit pattern such as an electrode is formed.

Therefore, as shown in FIGS. 2 and 3, the sputtering target 45 of one specific example of the present invention is provided with a groove 45a in a non-erosion region located at the center of the target surface, and the groove 45a has a plate shape. A member 49 is detachably fitted. Thereby, the particle deposit A attached to the non-erosion region of the sputtering target 45 during magnetron sputtering can be easily removed by removing the plate-like member 49.

That is, it is possible to suppress an increase in the amount of particles adhering to the long resin film F by replacing with a new plate-like member 49 before abnormal discharge due to arcing or peeling due to the insulating film deposited on the non-erosion portion frequently occurs. It becomes possible. As described above, when the sputtering target according to the present invention is used, since there is no adhesion of particles or the like on the surface of the long resin film that is the film formation surface, it is possible to form a homogeneous sputtering film that does not include foreign substances. Note that it is difficult to remove only the particle deposits in the non-erosion portion at the center of the sputtering target without using the plate-like member according to the present invention. In some cases, the sputtering target may be contaminated.

Since the non-erosion region also exists in the outer peripheral portion of the sputtering target as described above, it is conceivable to provide a member having the same function as the plate-like member provided in the central portion in the outer peripheral portion. However, if it is the outer peripheral portion of the sputtering target, for example, a rectangular frame-shaped cover member can be used to easily cover the sputtering without hindering the sputtering, thereby providing a plate-like member provided in the above-described non-erosion region of the central portion. The same function is obtained. The cover member is preferably detachably provided on the clamp 46 or the like by a coupling means such as a screw. Thereby, since it is only necessary to provide the sputtering target with a plate-like member only in the center portion, the processing cost of the sputtering target can be suppressed. In addition, it has been confirmed that defects such as particles of the sputtering film are drastically reduced even by providing a plate-like member only in the central portion without providing a cover member on the outer peripheral portion of the sputtering target.

The surface of the plate-like member 49 on the target surface side is substantially the same height as the target surface before erosion of the sputtering target 45 (shown by a one-dot chain line in FIG. 2) when fitted into the groove 45a of the sputtering target 45. Alternatively, it is preferably in a position recessed from the target surface before erosion. In other words, the surface of the plate-like member 49 on the target surface side preferably protrudes from the flat target surface before erosion of the sputtering target 45 and is not convex. If the plate-like member 49 protrudes from the target surface before erosion of the sputtering target 45, the electric field changes and abnormal discharge such as arc discharge occurs, or sputtering of the plate-like member 49 occurs. The composition of the film that is promoted and formed on the long resin film F may deviate from the desired composition, which is not desirable.

The plate member 49 is preferably made of the same material as the sputtering target 45. In the case where the material of the sputtering target 45 is an alloy, the plate-like member 49 may be constituted by a part of metal constituting the alloy composition of the sputtering target 45. In this way, the plate-like member 49 is made of the same material as the sputtering target 45, or when the sputtering target 45 is an alloy, the same metal as a part of the metal constituting them is used, so that the plate-like member 49 is plate-like. Even if the member 49 is sputtered, the film formed on the surface of the long resin film F can be prevented from being contaminated by the plate-like member 49 during the film formation. The plate-like member 49 may be attached to the sputtering target by a known attachment means such as a screw.

The surface of the plate-like member 49 on the target surface side preferably has a 10-point average roughness Rz of 10 μm or more and 500 μm or less, more preferably Rz 20 to 100 μm. When the surface roughness Rz of the plate-like member 49 is less than 10 μm, the anchor effect is reduced and the particle deposits are easily detached. On the other hand, when the surface roughness Rz exceeds 500 μm, abnormal discharge tends to occur at the top of the rough surface of the plate-like member 49 depending on the voltage applied to the sputtering cathode. For example, although depending on the structure of the sputtering cathode and the structure of the sputtering apparatus, when the surface roughness Rz of the plate-like member 49 is 750 μm, abnormal discharge may occur when 500 V is applied to the sputtering cathode. The surface roughness of the plate-like member 49 can be adjusted by shot blasting or thermal spraying.

Next, a laminate film obtained by performing reactive sputtering using the film forming apparatus provided with the sputtering target of one specific example of the present invention described above, and an electrode substrate film obtained by patterning the laminate film Will be described. Reactive sputtering of the first layer, counted from the transparent substrate side, on at least one surface of the transparent substrate made of a resin film, as will be described later, by the film forming apparatus provided with the sputtering target of one specific example of the present invention described above. The reaction of the first layer counted from the transparent substrate side on at least one surface of the first laminate film in which the film formation layer and the second metal layer are laminated or the transparent substrate made of the resin film A second laminated film in which a reactive sputtering film-forming layer, a second metal layer, and a third reactive sputtering film-forming layer are laminated can be produced.

First, the first laminate film will be described. For example, as shown in FIG. 4, the first laminate film includes a transparent substrate 50 made of a resin film, and a dry film forming method (dry method) on both surfaces of the transparent substrate 50. A reactive sputtering film formation layer 51 formed by a plating method) and a metal layer 52 formed by a dry film formation method (dry plating method) on the reactive sputtering film formation layer 51. Yes. And the film-forming apparatus provided with the sputtering target of the above-mentioned one specific example of this invention for film-forming of this reactive sputtering film-forming layer 51 can be used suitably. The metal layer 52 may be formed by only a dry film formation method (dry plating method) as shown in FIG. 4, or a dry film formation method (dry plating method) as shown in FIG. You may form combining a wet film-forming method (wet plating method).

That is, the laminate film shown in FIG. 5 has a transparent substrate 50 made of a resin film, and a reactivity of 15 to 30 nm thick formed on both surfaces of the transparent substrate 50 by a dry film forming method (dry plating method). A sputtering film formation layer 51, a metal layer 52 formed on the reactive sputtering film formation layer 51 by a dry film formation method (dry plating method), and a wet film formation method (wet process) on the metal layer 52 And a metal layer 53 formed by a plating method.

Next, the second laminate film will be described with reference to FIG. The second laminated film in FIG. 6 is obtained by further forming a second reactive sputtering film-forming layer on the metal layer of the first laminated film shown in FIG. Specifically, a transparent substrate 60 made of a resin film, and a reactive sputtering film forming layer 61 having a film thickness of 15 to 30 nm formed on both surfaces of the transparent substrate 60 by a dry film forming method (dry plating method); A metal layer 62 formed by a dry film formation method (dry plating method) on the reactive sputtering film formation layer 61 and a film formed by a wet film formation method (wet plating method) on the metal layer 62. The metal layer 63 and a second reactive sputtering film layer 64 having a film thickness of 15 to 30 nm formed on the metal layer 63 by a dry film forming method (dry plating method).

In the second laminate film shown in FIG. 6 described above, the reactive sputtering film forming layer 61 and the second reactive sputtering film forming layer 64 are formed on both surfaces of the metal layer in which the metal layer 62 and the metal layer 63 are integrated. ing. The reason for this is that when an electrode substrate film produced using the laminate film is incorporated in a touch panel, a circuit pattern having a mesh structure composed of metal laminated thin wires can be reflected and cannot be seen. In addition, an electrode substrate is formed using a first laminate film obtained by forming a reactive sputtering film-forming layer on one side of a transparent substrate made of a resin film and forming a metal layer on the reactive sputtering film-forming layer. Even when a film is produced, it is possible to prevent the circuit pattern from being visually recognized from the transparent substrate.

The reason why reactive sputtering is performed as described above is that, when an oxide target is applied for the purpose of forming a reactive sputtering film-forming layer made of a metal oxide, the film-forming speed becomes slow and is not suitable for mass production. is there. For this reason, a reactive film formation method such as reactive sputtering in which a Ni-based metal target (metal material) capable of high-speed film formation is introduced while a reactive gas containing oxygen is controlled is employed. As a method of controlling the reactive gas, (1) a method of releasing a reactive gas at a constant flow rate, (2) a method of releasing a reactive gas so as to maintain a constant pressure, and (3) an impedance of a sputtering cathode. Four methods are known: a method of releasing a reactive gas so that the plasma is constant (impedance control), and a method of (4) releasing a reactive gas so that the plasma intensity of sputtering is constant (plasma emission control). It has been.

As described above, when the reactive sputtering film is formed by the reactive sputtering method in which the reactive gas is introduced into the film forming apparatus, the reactive gas that becomes the sputtering atmosphere is obtained by introducing oxygen into argon. It is done. By introducing oxygen in this manner, a NiO film (not completely oxidized) or the like can be formed by reactive sputtering using a Ni-based metal target (metal material). The oxygen content of the reactive gas depends on the type of film deposition equipment and metal target (metal material), and is set as appropriate in consideration of optical characteristics such as reflectivity in the reactive sputtering film deposition layer and etchability with an etchant. In general, it is preferably 15% by volume or less.

The reactive sputtering film-forming layer is a metal composed of Ni alone or a Ni-based alloy to which one or more elements selected from Ti, Al, V, W, Ta, Si, Cr, Ag, Mo, and Cu are added. It is formed by a reactive film formation method using a reactive gas containing a material and oxygen. The Ni-based alloy is preferably a Ni—Cu alloy. Moreover, since the reactive sputtering film-forming layer becomes transparent when the oxidation of the metal oxide constituting the reactive sputtering film-forming layer proceeds excessively, it is necessary to set the oxidation level to such a level that it becomes a blackened film.

Note that examples of the reactive film forming method include ion beam sputtering, vacuum deposition, ion plating, CVD, and the like, in addition to magnetron sputtering using the sputtering target of the present invention described above. In addition, the optical constants (refractive index, extinction coefficient) at each wavelength of the reactive sputtering layer are greatly influenced by the degree of reaction, that is, the degree of oxidation, and are determined only by a metal material made of a Ni-based alloy. is not.

The constituent material (metal material) of the metal layer is not particularly limited as long as it is a metal having a low electrical resistance value, and is selected from, for example, Cu alone, Ti, Al, V, W, Ta, Si, Cr, or Ag. A Cu-based alloy to which one or more elements are added, an Ag-based alloy, or an Ag-based alloy to which one or more elements selected from Ti, Al, V, W, Ta, Si, Cr, and Cu are added. In particular, Cu alone is desirable from the viewpoint of processability and resistance value of the circuit pattern. The thickness of the metal layer depends on the electrical characteristics and is not determined from optical elements, but is usually set to a thickness at which transmitted light cannot be measured.

The material of the resin film applied to the laminate film is not particularly limited, and specific examples thereof include polyethylene terephthalate (PET), polyethersulfone (PES), polyarylate (PAR), and polycarbonate (PC). A single resin film selected from polyolefin (PO), triacetyl cellulose (TAC) and norbornene resin materials, or a single resin film selected from the above resin materials and an acrylic organic covering one or both sides of the single resin film A complex with a membrane may be mentioned. In particular, as for norbornene resin materials, representative examples include ZEONOR (trade name) manufactured by Nippon Zeon Co., Ltd. and Arton (trade name) manufactured by JSR Corporation. In addition, since the electrode substrate film produced using the laminated body film concerning this invention is used for a "touch panel" etc., what is excellent in the transparency in a visible wavelength region among the said resin films is desirable.

The electrode substrate film can be produced by patterning the first or second laminated film as described above and wiring the laminated thin line having a line width of 20 μm or less, for example. For example, a method for obtaining a sensor panel made of a metal mesh from the above-described second laminate film will be described. In the following description, a sensor panel made of a metal mesh is referred to as an electrode substrate film. Specifically, an electrode substrate film as shown in FIG. 7 can be obtained by etching the laminated film of the laminate film shown in FIG.

The electrode substrate film shown in FIG. 7 has a circuit pattern having a mesh structure composed of a transparent substrate 70 made of a resin film and metal laminated thin wires provided on both surfaces of the transparent substrate 70. However, the first reactive sputtering deposition layer 71, the second metal layers 72 and 73, and the second reactivity of the third layer are counted from the transparent substrate 70 side. And a sputtering film-forming layer 74.

The wiring process from the laminate film to the electrode substrate film can be performed by a known subtractive method. In the subtractive method, a photoresist film is formed on the laminate film surface of the laminate film, exposed and developed so that the photoresist film remains at the location where the wiring pattern is to be formed, and there is a photoresist film on the laminate film surface. The laminated film at the portion not to be removed is removed by chemical etching. As an etching solution for chemical etching, an aqueous solution of ferric chloride or an aqueous solution of cupric chloride can be used.

From the viewpoint of the production process of such an electrode substrate film, the laminated film (reactive sputtering film forming layer and metal layer) constituting the laminated film is etched with an etchant such as a cupric chloride aqueous solution or a ferric chloride aqueous solution. It is preferable to have a characteristic that is easily processed. Moreover, it is preferable that circuit patterns, such as an electrode processed by etching, have a characteristic that is difficult to be visually recognized under high luminance illumination.

The electrode substrate film according to the present invention can be used for a touch panel by forming the electrode (wiring) pattern of the electrode substrate film thus formed into a stripe shape or a lattice shape for a touch panel. At that time, the metal thin wire processed into the electrode (wiring) pattern maintains the laminated structure of the laminated film, so that the circuit such as the electrode provided on the transparent substrate even under high luminance illumination. The pattern can be provided as an electrode substrate film that is extremely difficult to be visually recognized.

Examples of the present invention will be specifically described below with reference to comparative examples, but the present invention is not limited to the following examples.
[Example]
A laminate film as shown in FIG. 4 was produced using a film forming apparatus (sputtering web coater) as shown in FIG. A stainless steel roll having a diameter of 600 mm and a width of 750 mm was used for the can roll 16, and the outer peripheral surface was subjected to hard chrome plating. The front feed roll 15 and the rear feed roll 21 were stainless steel rolls having a diameter of 150 mm and a width of 750 mm, and the outer peripheral surfaces thereof were subjected to hard chrome plating.

Gas discharge pipes

25, 26, 27, 28, 29, 30, 31, and 32 were installed on the upstream side and downstream side of each

magnetron sputtering cathode

17, 18, 19, and 20, respectively. The

magnetron sputtering cathodes

17 and 18 were Ni—Cu targets for reactive sputtering film formation layers. As shown in FIG. 3, a groove extending in the longitudinal direction of the cathode is formed in the central portion of the target surface of the Ni—Cu target so that the surface roughness on the surface of the target surface is sufficient. A Cu plate-like member blasted to have a point average roughness Rz of 50 μm was fitted into this groove. The surface on the target surface side of the plate-like member and the target surface of the Ni—Cu target were set to the same height. On the other hand, an ordinary Cu target for a metal layer was attached to the

magnetron sputtering cathodes

19 and 20.

The long resin film F constituting the transparent substrate was a PET film having a width of 600 mm and a length of 1200 m, and the can roll 16 was controlled to be cooled to 0 ° C. In this state, the vacuum chamber 11 was evacuated to 5 Pa using a plurality of dry pumps, and further evacuated to 1 × 10 ⁻⁴ Pa using a plurality of turbo molecular pumps and cryocoils. Then, while transporting the long resin film F at a transport speed of 2 m / min, argon gas was introduced at 300 sccm from the

gas release pipes

29, 30, 31, and 32, and a Cu film thickness of 80 nm was obtained for the

cathodes

19 and 20. As shown, film formation was performed with power control.

On the other hand, in order to form a reactive sputtering film-forming layer, a mixed gas obtained by mixing 280 sccm of argon gas and 15 sccm of oxygen gas is introduced from the

gas release pipes

25, 26, 27, and 28. Film formation was performed under power control around an applied voltage of 500 V so that a Cu oxide film thickness of 30 nm was obtained. Then, a total of 12 lots of laminate films were produced while replacing the plate-like member at the center with a new one every 3 lots. When adhesion of particles of 10 μm or more was confirmed on the obtained laminate film by an image inspection apparatus based on image analysis of a computer, 53 particles / lot on average were confirmed.

[Example 2]
A total of 12 lots of laminate films were produced in the same manner as in Example 1 except that the surface roughness of the plate member made of Cu was 10 μm in terms of the ten-point average roughness Rz. Adhesion of particles of 10 μm or more in the obtained laminate film was confirmed by the same method as in Example 1, and an average of 61 particles / lot was confirmed.

[Example 3]
A total of 12 lots of laminate films were produced in the same manner as in Example 1 except that the surface roughness of the plate member made of Cu was 20 μm in terms of the ten-point average roughness Rz. When adhesion of particles of 10 μm or more in the obtained laminate film was confirmed by the same method as in Example 1, particles of 55 particles / lot on average were confirmed.

[Example 4]
A total of 12 lots of laminate films were prepared in the same manner as in Example 1 except that the surface roughness of the plate member made of Cu was 200 μm in terms of the ten-point average roughness Rz. When adhesion of particles of 10 μm or more on the obtained laminate film was confirmed by the same method as in Example 1, particles of an average of 58 particles / lot were confirmed.

[Example 5]
A total of 12 lots of laminate films were produced in the same manner as in Example 1 except that the surface roughness of the plate member made of Cu was 450 μm in terms of the ten-point average roughness Rz. When adhesion of particles of 10 μm or more on the obtained laminate film was confirmed by the same method as in Example 1, particles of an average of 58 particles / lot were confirmed.

[Example 6]
A total of 12 lots of laminate films were produced in the same manner as in Example 1 except that the surface roughness of the plate member made of Cu was changed to a 10-point average roughness Rz of 5 μm. When adhesion of particles of 10 μm or more in the obtained laminate film was confirmed by the same method as in Example 1, particles of 130 particles / lot on average were confirmed.

[Comparative Example 1]
A total of 12 laminate films were prepared in the same manner as in Example 1 except that the conventional target was used as the Ni—Cu target for the reactive sputtering film formation layer. The adhesion of particles of 10 μm or more in the obtained laminate film was confirmed by the same method as in Example 1, and an average of 370 particles / lot was confirmed.

In a laminate film of 1 lot of 1200 m, it is desirable that the number of particles of 10 μm or more is small. Specifically, if it is 150 pieces / lot or less, practical problems are less likely to occur, but 100 pieces / lot or less are more desirable. As described above, in Examples 1 to 6 using the sputtering target according to the present invention, the number of particles of 10 μm or more could be suppressed to 150 particles / lot or less. On the other hand, in Comparative Example 1 using a conventional sputtering target, the number of particles of 10 μm or more, which is twice or more than 150 / lot, was generated.

A Particle deposit F Long resin film 10 Sputtering web coater 11 Vacuum chamber 11a Partition plate 12 Unwinding roll 13 Free roll 14 Tension sensor roll 15 Front feed roll 16 Can roll 17, 18, 19, 20 Magnetron sputtering cathode 21 Rear feed Roll 22 Tension sensor roll 23 Free roll 24

Winding roll

25, 26, 27, 28, 29, 30, 31, 32 Gas release pipe 40 Magnetron sputtering cathode 41 Housing 41a Housing 41b Housing cover 42 Magnetic circuit 42a Magnet 42b York 43 Cooling plate 44 Cooling water channel 45 Sputtering target 45a Groove 46 Clamp 47 Ground shield 48 Insulating plate 49 Plate member 50 Resin Irumu (transparent substrate)
51 Reactive sputtering layer 52 Metal layer (copper layer) formed by dry deposition method
53 Metal layer (copper layer) formed by wet film formation method
60 Resin film (transparent substrate)
61 Reactive sputtering deposition layer 62 Metal layer (copper layer) formed by dry deposition method
63 Metal layer (copper layer) formed by wet film formation method
64 Second reactive sputtering film-forming layer 70 Resin film (transparent substrate)
71 Reactive sputtering film-forming layer 72 Metal layer (copper layer) formed by dry film-forming method
73 Metal layer (copper layer) formed by wet film formation method
74 Second reactive sputtering layer

Claims

A sputtering target used for magnetron sputtering, wherein a plate-like member is detachably fitted in a non-erosion region located at the center of the target surface of the sputtering target.
The surface of the plate-like member on the target surface side is approximately the same height as the target surface before erosion of the sputtering target when fitted into the sputtering target, or is disposed at a position recessed from the target surface. The sputtering target according to claim 1, wherein:
3. The sputtering target according to claim 1, wherein the surface roughness of the plate-like member on the target surface side is 10 μm or more and 500 μm or less at a 10-point average roughness Rz.
The sputtering target according to claim 3, wherein the surface of the plate-like member on the target surface side is roughened by shot blasting or thermal spraying.
Sputtering film formation characterized by performing reactive sputtering film formation using a sputtering cathode equipped with the sputtering target according to any one of claims 1 to 4 in an atmosphere to which a reactive gas is supplied. Method.
6. The sputtering film forming method according to claim 5, wherein the reactive gas is any one of oxygen, nitrogen, and steam.