Patent Description:
Conventionally, vacuum deposition devices are often used in forming films of electrode materials, in processes for forming electrodes in various devices such as semiconductor devices, solar cells, liquid crystal displays, and organic EL displays. However, because it is difficult to control the film thickness distribution, both spatially and temporally, in the vacuum deposition method, there has been a demand for electrode material film formation by way of a sputtering method.

Conventionally, parallel-plate magnetron sputtering devices, RF sputtering devices, facing-target sputtering devices, and the like have been known as sputtering devices. With facing-target sputtering devices, two equally sized circular, square, or rectangular targets made of the same material face each other, in parallel, a sputtering gas is introduced into the space therebetween, and discharge is performed, whereby film formation is performed by sputtering the targets (see, for example, Non-patent Documents <NUM> to <NUM>). These facing-target sputtering devices produce a sputtering phenomenon by confining the plasma to the space that lies between two targets, which is to say, in a space surrounded by the two targets and magnetic force lines formed at the outer periphery. Sputtering cathodes of this type have an advantage in that the target is disposed perpendicular to the substrate, so that reflected neutral process-gas particles can be prevented from bombarding the surface of the film-receiving substrate.

However, the facing-target sputtering device described above has a disadvantage in that the plasma density between the two facing targets is low, such that sufficiently high film forming speeds cannot be achieved.

In order to solve these problems, the present inventor has proposed a sputtering cathode having a sputtering target, the shape of which is tubular, having a pair of mutually facing long-side portions, in which the erosion surfaces face inward (see Patent Document <NUM>). With this sputtering cathode, film formation can be performed on a flat film-receiving body, at a sufficiently high film forming speed, and with low bombardment.

<CIT> and <CIT> disclose a sputtering cathode having a sputtering target having a tubular shape in which the cross-sectional shape thereof has a pair of long side sections facing each other, and an erosion surface facing inward. Using the sputtering target, while moving a body to be film-formed, which has a film formation region having a narrower width than the long side sections of the sputtering target, parallel to one end face of the sputtering target and at a constant speed in a direction perpendicular to the long side sections above a space surrounded by the sputtering target, discharge is performed such that a plasma circulating along the inner surface of the sputtering target is generated, and the inner surface of the long side sections of the sputtering target is sputtered by ions in the plasma generated by a sputtering gas to perform film formation in the film formation region of the body to be film-formed. <CIT> discloses a processing roller wound with a film to be processed by film deposition on a roll-to-roll basis having, at least at an effective part, a cylinder part which has a flow passage formed inside and is made of copper, copper alloy, aluminum, or aluminum alloy. On a surface of the cylinder part, a coating layer is formed as needed which is formed of a material higher in hardness than the material forming the cylinder part. The flow passage inside the cylinder part is typically in a shape which is bent zigzag having a part extending linearly in a circumferential direction of the cylinder part and a folded part, and has a rectangular cross-sectional shape parallel with the center axis of the cylinder part. <CIT> (Patent Document <NUM>) discloses a sputtering cathode, a sputtering apparatus, and a method for manufacturing a film-formed body, which are capable of forming a film on a plate-shaped film-formed body at a sufficiently high film-forming rate and with a low impact. A sputtering cathode has a tubular cross-sectional shape with a pair of long sides facing each other, and has a sputtering target with an erosion surface facing inward. Using this sputtering cathode, a film-forming object having a film-forming region narrower than the long side of the sputtering target above the space surrounded by the sputtering target is parallel to one end surface of the sputtering target and the long side is While moving at a constant speed in a direction perpendicular to the sputtering target, discharge is performed so as to generate plasma that circulates along the inner surface of the sputtering target, and the inner surface of the long side of the sputtering target is caused by ions in the plasma generated by the sputtering gas. Sputtering is performed to form a film on a film-forming region of the object to be film-formed.

<CIT> discloses a sputter method and a sputter device, wherein lowtemperature and low-damage film formation are performed in the first film formation part of a first film formation region, so as to form an initial layer of film with a prescribed thickness on a substrate, thereafter, the substrate is moved to a second film formation part of a second film formation region, and subsequently, film formation is performed at a high film formation rate, so as to form a second layer of film, thus a thin film is formed. <CIT> discloses a magnetron sputtering apparatus for forming an optical thin film on a substrate, the sputtering target having a concave erosion surface with a substantially elliptic cylinder shape.

However, the usage efficiency of the sputtering target in the sputtering cathode according to Patent Document <NUM> is not necessarily sufficient, and thus there is room for improvement. Meanwhile, it could not be said that the sputtering device according to Patent Document <NUM> was necessarily readily able to support, for example, situations in which a thin film is to be formed on a large-area substrate in a stationary state.

Here, an object of the disclosure, which is not part of the invention, is to provide a sputtering cathode with which film formation can be performed on various film-receiving bodies, including flat film-receiving bodies, at a sufficiently high film forming speed, and with low bombardment, and which moreover has high sputtering target usage efficiency, and to provide a sputtering device using this sputtering cathode.

An object of this invention is to provide a sputtering cathode with which film formation can be performed on various film-receiving bodies, including flat film-receiving bodies, at a sufficiently high film forming speed, and with low bombardment, and which moreover can perform sputtering stably by way of preventing deposition of foreign matter such as dust, which is produced during film formation, on the sputtering target, and to provide a sputtering device using this sputtering cathode.

The aforementioned and other objects will be apparent from the description in the present specification, referring to the accompanying drawings.

In order to achieve the aforementioned objects, a sputtering cathode is disclosed, which does not form part of the invention, as follows:.

Here, the rotary target has a cylindrical shape and is provided so as to be rotatable about the central axis thereof by a predetermined rotation mechanism. Typically, the rotary target is configured such that a magnetic circuit is provided at the interior and cooling water can flow at the interior. The magnetic circuit typically has a rectangular cross-sectional shape with long sides parallel to the central axes of the rotary targets and perpendicular to the radial directions of the rotary targets. In this case, in the magnetic circuit provided at the interior of one rotary target and in the magnetic circuit provided at the interior of the other rotary target, the angle of inclination of the short side of the rectangular cross-sectional shape with respect to the plane including the central axis of one rotary target and the central axis of the other rotary target is <NUM> or more and less than <NUM> degrees, and by setting the angle of inclination to any angle within this range, a good balance can be achieved between increased film forming speed and a low damage.

In this disclosure, with a view to ensuring a sufficient number of sputtered particles directed to the space above the sputtering target when the sputtering cathode is used mounted in a sputtering device, and with a view to preventing reflected neutral process gas particles from impacting and bombarding the film-receiving body, typically, the distance between the rotary targets constituting the pair of mutually facing long-side portions of the sputtering target is preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>, and most preferably <NUM> to <NUM>. Furthermore, ratio of the length of the long-side portions to the distance between the rotary targets constituting the pair of long-side portions of the sputtering target is typically <NUM> or more, and preferably <NUM> or more. There is no particular upper limit for this ratio, but it is generally no greater than <NUM>.

The rotary targets constituting the pair of long side portions of the sputtering target are typically mutually parallel, but there is no limitation to this, and these may be mutually inclined. The cross-sectional shape of the sputtering target is typically such that the pair of long-side portions are mutually parallel, and a pair of mutually facing short-side portions are provided, which are perpendicular to the long-side portions. In this case, the sputtering target has a rectangular tubular shape having a rectangular cross-section. The cross-sectional shape of the sputtering target may comprise, for example, a pair of mutually facing curved surface portions (for example, semicircular portions), the two ends of which project outwardly in a direction parallel to the long-side portions. A sputtering target having a rectangular tubular shape having a rectangular cross-section typically comprises a pair of rotary targets constituting a pair of long-side portions, and two flat plates forming a pair of mutually facing short-side portions perpendicular to the long-side portions. In this case, these rotary targets and flat plates are separately fabricated, and the sputtering target can be assembled by arranging these in the form of a rectangular tube. The rotary targets constituting the pair of long-side portions are generally made of a material having the same composition as that of the material with which the film is to be formed, but these may be made of mutually different materials. For example, by making a first rotary target from a material A, making a second rotary target from a material B, and causing the sputtered particle flux from the first rotary target and the sputtered particle flux from the second rotary target to be incident on the film-receiving body, a thin film comprising A and B can be formed, and by using materials with two or more components as the materials A and B, a thin film comprising a multicomponent material can be formed, as necessary. More specifically, for example, by making a first rotary target from a metal M1 comprising a single element and making a second rotary target from a metal M2 comprising a single element, a binary alloy thin film comprising M1 and M2 can be formed. This means that a film forming method similar to the binary deposition method in vacuum deposition methods can be achieved with a sputtering device. Further, for example, by inserting a removable shielding plate between the film-receiving body and a sputtering target, for example, so as to block the sputtered particle flux from the second rotary target, and moving the film-receiving body while the sputtered particle flux from the first rotary target is incident on the film-receiving body, a thin film comprising A can be first formed on the film-receiving body, and then, by shielding the sputtered particle flux from the first the rotary target and causing the sputtered particle flux from the second rotary target to be incident on the film-receiving body, while moving the film receiving body in the opposite direction, a thin film comprising B can be formed on the film receiving body. Thus, a thin film having a two-layer structure of a thin film comprising A and a thin film comprising B can be formed on the film-receiving body.

In general, the sputtered particle flux from portions other than the pair of long-side portions of the sputtering target is not actively used for film formation, but in order to prevent contamination with unintended elements, the portions other than the pair of long-side portions of the sputtering target are typically made of the same material as the long-side portions. However, if the sputtered particle flux from the portions other than the pair of long-side portions of the sputtering target are deliberately not used for film formation, the portions other than the rotary target constituting the pair of long-side portions of the sputtering target may be made of a material different from that of the rotary targets constituting the pair of long-side portions.

Since the sputtered particle flux can be extracted from the sputtering target, not only above, but also below the space surrounded by the sputtering target, as necessary, film formation may also be performed on a film formation region of another film-receiving body, while moving this film-receiving body with respect to the sputtering target at a constant speed, in a direction traversing the long-side portion of the sputtering target, below the space surrounded by the sputtering target.

In order to achieve the aforementioned objects, this invention defines a sputtering cathode, in accordance with claim <NUM>.

In this invention, at least one of two portions of the sputtering target other than the pair of long-side portions is curved, relative to a plane or curve including the pair of long-side portions, forming a curved surface in which the erosion surface is twisted, from one long-side portion side of the pair of long-side portions, and extending to the other long-side portion side of the pair of long-side portions, and is, midway, oriented in the vertical direction or in the front-rear direction, so that foreign matter produced during film formation can be prevented from being deposited on the sputtering target. The pair of long-side portions is each formed from a flat plate. features, unless contrary to the nature thereof, shall be deemed to have been explained in connection with the aspect of the disclosure described above.

Each sputtering cathode typically comprises a first flat plate and a second flat plate constituting a pair of long-side portions, and a third flat plate and a fourth flat plate constituting a pair of mutually facing short-side portions perpendicular to the long-side portions. In this case, this first flat plate, second flat plate, third flat plate and fourth flat plate are separately fabricated, and the sputtering target can be assembled by arranging these in the form of a rectangular tube. The first flat plate and the second flat plate constituting the pair of long-side portions are generally made of a material having the same composition as that of the material with which the film is to be formed, but these may be made of mutually different materials. For example, by making the first flat plate from a material A, making the second flat plate from a material B, and causing the sputtered particle flux from the first flat plate and the sputtered particle flux from the second flat plate to be incident on the film-receiving body, a thin film comprising A and B can be formed, and by using materials with two or more components as the materials A and B, a thin film comprising a multicomponent material can be formed, as necessary. More specifically, for example, by making the first flat plate from a metal M1 comprising a single element and making the second flat plate from a metal M2 comprising of a single element, a binary alloy thin film comprising M1 and M2 can be formed. Typically, the polarities of magnetic circuits of a pair of mutually adjacent sputtering cathodes are mutually the same. That is to say, if the magnetic circuit in one of the pair of mutually adjacent sputtering target surfaces is an N-pole, the corresponding portion of the other adjacent magnetic circuit is also an N-pole.

If necessary but not forming part of the invention, the pair of long-side portions may each comprise rotary targets. Furthermore, if necessary but not being part of the invention, each sputtering cathode has an auxiliary magnetic pole in the vicinity of a portion of the sputtering target facing the space where the film formation is to be performed. Other features, unless contrary to the nature thereof, shall be deemed to have been explained in connection with the disclosure described above.

Furthermore, a sputtering device is disclosed, which does not form part of the invention, wherein the sputtering device has:.

Furthermore, this invention defines a sputtering device, in accordance with claim <NUM>.

Furthermore, a sputtering device is disclosed, which is compatible with the invention, wherein the sputtering device has:.

Here, an AC power source is typically connected between two mutually adjacent sputtering cathodes among the plurality of sputtering cathodes arranged in parallel, and an AC voltage is applied thereto. Thus, two mutually adjacent sputtering cathodes can alternately repeat between negative electrode and positive electrode, whereby sputtering can be alternately performed, and an anode loss phenomenon, which is caused by the deposition of an insulating film on the anode, can be avoided, thereby achieving reactive sputtering film formation having long-term stability, with low damage.

With each of the sputtering devices described above, film formation can be performed in a film formation region on the film-receiving body by sputtering the inner surfaces of the long-side portions of the sputtering targets with ions in plasma generated from sputtering gas, by performing discharge so as to generate a plasma that circulates along the inner surfaces of the sputtering targets, while moving a film receiving body having a film formation region with a width that is narrower than the long-side portions of the sputtering target, relative to the sputtering target, above a space surrounded by the sputtering target, at a constant speed, in a direction that traverses the long sides of the sputtering targets, or with this in a stationary state above the space surrounded by the sputtering target. In the invention for the sputtering device described above, other features, unless contrary to the nature thereof, shall be deemed to have been explained in connection with the aspects of the invention for the sputtering cathode described above.

Furthermore, in the invention for the sputtering cathode, and the sputtering device described above, in order to prevent positive ions generated from the sputtering gas from bombarding the film-receiving body during film formation and thereby causing damage to the film-receiving body and the thin film formed on the film-receiving body, preferably, the voltage applied between the sputtering cathode and an anode provided so as to expose the erosion surface of the sputtering target is a pulse waveform, and the high level of the voltage pulse at the sputtering cathode is <NUM> V, or a negative voltage V<NUM>-, the absolute value of which is about <NUM> V or less, and the low level is a negative voltage VL-, the absolute value of which is about <NUM> V or more, whereby a positive voltage is not applied.

According to this invention, the sputtering target of the sputtering cathode has a shape which is rectangular tubular, having a pair of mutually facing long-side portions, which is to say, a shape surrounded by four sides, and the erosion surface faces inward, whereby, when the sputtering cathode is mounted in the sputtering device and discharge is performed, plasma which circulates at the inner surface of the sputtering target can be generated at the erosion surface side of the sputtering target. Therefore, the film forming speed can be sufficiently increased by increasing the plasma density. Furthermore, since the location in which the majority of the plasma is generated is limited to the vicinity of the surface of the sputtering target, it is possible to minimize the risk of damage occurring due to irradiation of the film-receiving body by light emitted from the plasma. Furthermore, in particular, by causing at least one of two portions of the sputtering target other than the pair of long-side portions to have a shape which is curved, relative to a plane or curve including the pair of long-side portions, forming a curved surface in which the erosion surface is twisted, from one long-side portion side of the pair of long-side portions, and extending to the other long-side portion side of the pair of long-side portions, foreign matter produced during film formation can be prevented from being deposited on that portion of the sputtering target, thus allowing sputtering to be performed stably.

Hereafter, embodiments, including certain embodiments of the invention, will be described with reference to the drawings.

<FIG> and <FIG> are a longitudinal cross-sectional view and a plan view showing a sputtering device according to the first embodiment, which is compatible with the invention, which show the configuration in the vicinity of a sputtering cathode assembly, not being part of the invention, provided inside a vacuum vessel of the sputtering device. <FIG> is a cross-sectional view along the line X-X in <FIG>.

As shown in <FIG> and <FIG>, in this sputtering device, a plurality of sputtering cathodes are arranged in parallel on a horizontal plane, and a sputtering cathode assembly is formed by these sputtering cathodes. The number of sputtering cathodes constituting the sputtering cathode assembly is selected as appropriate, in accordance with the size of the substrate on which the film is to be formed, the method with which the film is to be formed, and the like. In <FIG> and <FIG>, only one mutually adjacent pair of sputtering cathodes <NUM> and <NUM> is shown, by way of example, but the there is no limitation to this. The spacing between the sputtering cathodes <NUM> and <NUM> is selected as appropriate, in accordance with the size of the substrate on which the film is to be formed and the method with which the film is to be formed. If three or more sputtering cathodes constitute the sputtering cathode assembly, the spacing between the sputtering cathodes is generally equal, but this does not necessarily have to be equal, and in such cases, the spacing is selected as required.

The sputtering cathode <NUM> has: a sputtering target <NUM> having a rectangular tubular shape having a rectangular cross-section and erosion surfaces facing inward, permanent magnets <NUM> provided outside the sputtering target <NUM>, and a yoke <NUM> provided outside the permanent magnets <NUM>. The sputtering target <NUM>, the permanent magnets <NUM>, and the yoke <NUM> form the sputtering cathode <NUM>. The sputtering cathode <NUM> is generally fixed to the vacuum vessel in an electrically insulated manner. A magnetic circuit is formed by the permanent magnets <NUM> and the yoke <NUM>. The polarities of the permanent magnets <NUM> are as shown in <FIG>, but the polarities may also be respectively the exact opposites, the latter not being part of the invention. A cooling backing plate is preferably provided between the sputtering target <NUM> and the permanent magnets <NUM>, and cooling water, for example, flows in a flow path provided inside the backing plate. An anode <NUM> having an L-shaped cross-section is provided in the vicinity of the lower end of a rectangular parallelepiped space surrounded by the sputtering target <NUM> so that the erosion surface of the sputtering target <NUM> is exposed. This anode <NUM> is generally connected to the grounded vacuum vessel. Furthermore, a light blocking shield <NUM> having an L-shaped cross-section is provided in the vicinity of the upper end of the rectangular parallelepiped space surrounded by the sputtering target <NUM> so that the erosion surface of the sputtering target <NUM> is exposed. The light blocking shield <NUM> is formed from a conductor, and typically from a metal. The light blocking shield <NUM> also serves as an anode and is generally connected to the grounded vacuum vessel, in the same manner as the anode <NUM>. An auxiliary magnetic pole <NUM>, not being part of the invention, having an L-shaped cross section is provided between the light blocking shield <NUM> and the sputtering target <NUM>, so as to expose the erosion surface of the sputtering target <NUM>. The auxiliary magnetic pole <NUM> serves to prevent magnetic force lines formed by the magnetic circuit, which is formed by the permanent magnets <NUM> and the yoke <NUM>, from leaking into the space above the sputtering cathode <NUM>, where the film formation is to be performed, and the arrangement of this magnetic pole is selected so as to cancel out magnetic force lines that leak above the sputtering cathode <NUM>.

The sputtering cathode <NUM> is the same as the sputtering cathode <NUM> except that the polarities of the permanent magnets <NUM> are opposite to the polarities of the permanent magnets <NUM> of the sputtering cathode <NUM> as shown in <FIG>, the opposite polarities not being part of the invention. The same is true in cases where there are other sputtering cathodes, with a pair of mutually adjacent sputtering cathodes being mutually identical, except that the permanent magnets <NUM> have mutually opposite polarities, and having a mutually identical orientation. Since the polarities of the permanent magnets <NUM> in the pair of mutually adjacent sputtering cathodes are thus mutually opposite, due to the magnetic force lines formed by the magnetic circuits, which are formed by the permanent magnets <NUM> and the yokes <NUM>, when a pair of AC sputtering powers are applied to both sputtering cathodes, as shown in <FIG>, plasma moving to the adjacent electrode is confined to the space below the sputtering cathode assembly, and plasma leakage to the space in which the film formation above the sputtering cathode assembly is performed can be effectively prevented. Further, a separate auxiliary magnetic pole, not being part of the invention, may be used in the lower space to make the plasma movement to the adjacent sputtering cathode more effective.

As shown in <FIG>, where a is the distance between a pair of mutually facing long-side portions of the sputtering target <NUM> of each sputtering cathode constituting the sputtering cathode assembly, and b is the distance between a pair of mutually facing short-side portions of the sputtering target <NUM>, b/a is selected to be <NUM> or more, and is generally selected to be <NUM> or less, but is not limited thereto. a is generally selected from <NUM> to <NUM>, but is not limited to this thereto.

As shown in <FIG>, in this sputtering device, film formation is performed on a substrate S (film-receiving body), which is held by a non-illustrated predetermined transport mechanism, in a space above the sputtering cathode assembly. The film formation may be performed while the substrate S is being moved with respect to the sputtering targets <NUM> of the sputtering cathodes, in a direction traversing the long-side portions of the sputtering targets <NUM>, typically in a direction parallel to the upper end faces of the sputtering targets <NUM> and perpendicular to the long-side portions of the sputtering targets <NUM>, and typically at a constant speed, or may be performed in a stationary state with the substrate S stationary above the sputtering cathode assembly. The width of the film formation region on the substrate S, in the direction parallel to the long-side portion of the sputtering target <NUM>, is selected to be less than b so that, during film formation, this lies between the pair of mutually facing short-side portions on the inside of the sputtering target <NUM>. If the film formation is to be performed on the entire surface of the substrate S, the width of the film formation region of the substrate S coincides with the width of the substrate S. The substrate S may basically be of any kind, and is not particularly limited. The substrate S may be in the form of a long film, wound on a roll, as used in so-called roll-to-roll processes.

Before film formation, the substrate S is located at a position sufficiently far from the top of the space surrounded by the sputtering target <NUM>.

After the vacuum vessel is evacuated to a high vacuum by a vacuum pump, Ar gas is introduced, as a sputtering gas, into the space surrounded by the sputtering target <NUM>, and an AC voltage necessary for plasma generation is applied between the anodes <NUM> and the sputtering cathodes <NUM> and <NUM>, from a predetermined power supply. Typically, the anodes <NUM> are grounded, and a high AC voltage (for example, -<NUM> V) is applied between the sputtering cathode <NUM> and the sputtering cathode <NUM>. Thus, while a negative high voltage is applied to the sputtering cathode <NUM>, a plasma <NUM> is generated in the vicinity of the surface of the sputtering target <NUM>, which circulates along the inner surface of the sputtering target <NUM>, as shown in <FIG> and <FIG>. The plasma <NUM> is not generated while a negative high voltage is not applied to the sputtering cathode <NUM>. Furthermore, while a negative high voltage is applied to the sputtering cathode <NUM>, a plasma <NUM> is generated in the vicinity of the surface of the sputtering target <NUM> of the sputtering cathode <NUM>, which circulates along the inner surface of the sputtering target <NUM> of the sputtering cathode <NUM>. The plasma <NUM> is not generated while a negative high voltage is not applied to the sputtering cathode <NUM>. As shown in <FIG> and <FIG>, as a result of sputtering the sputtering target <NUM> with Ar ions in the plasma <NUM> circulating along the inner surface of the sputtering target <NUM>, atoms comprised by the sputtering target <NUM> are ejected upward from the space surrounded by the sputtering target <NUM>. At this time, atoms are ejected from all parts of the erosion surface of the sputtering target <NUM> near the plasma <NUM>, but atoms that are ejected from the erosion surface of the short side portion of the inside of the sputtering target <NUM> are essentially not used for film formation. Therefore, horizontal shielding plates may be provided above the sputtering target <NUM> so as to shield both end portions, in the long side direction, of the sputtering target <NUM>, so that atoms ejected from the erosion surfaces of the short-side portions of the sputtering target <NUM> do not reach the substrate S during film formation. Alternatively, the width b of the sputtering target <NUM> in the longitudinal direction may be made sufficiently greater than the width of the substrate S, so that atoms ejected from the erosion surfaces on the short-side portions of the sputtering target <NUM> do not reach the substrate S during film formation. As shown in <FIG>, as a result of some of the atoms ejected from the sputtering target <NUM> being shielded by the light blocking shield <NUM>, sputtered particle fluxes <NUM>, <NUM> are produced from the erosion surfaces of the long-side portions of the sputtering target <NUM>. The sputtered particle fluxes <NUM>, <NUM> have substantially uniform intensity distributions in the longitudinal direction of the sputtering target <NUM>. Meanwhile, while a negative high voltage is applied to the sputtering cathode <NUM>, a plasma <NUM> is generated in the vicinity of the surface of the sputtering target <NUM>, which circulates along the inner surface of the sputtering target <NUM>, as shown in <FIG> and <FIG>, and as a result, sputtering is performed by the sputtered particle fluxes <NUM>, <NUM>. The plasma <NUM> is not generated while a negative high voltage is not applied to the sputtering cathode <NUM>, and sputtering does not occur. That is to say, as can be understood from the foregoing description, the sputtering cathode <NUM> and the sputtering cathode <NUM> are used alternately.

First, a case in which film formation is performed while moving the substrate S will be described.

When stable sputtered particle fluxes <NUM>, <NUM> from the sputtering targets <NUM> of the sputtering cathodes <NUM>, <NUM> have been produced, film formation is performed with the sputtering particle fluxes <NUM>, <NUM>, while moving the substrate S with respect to the sputtering target <NUM> of the sputtering cathode <NUM> at a constant speed, in the direction traversing the long-side portions of the sputtering target <NUM>. When the substrate S moves above the space surrounded by the sputtering target <NUM>, first, the sputtered particle flux <NUM> is incident on the substrate S, and film formation begins. <FIG> shows the situation at the point in time when the leading edge of the substrate S has approached above the vicinity of the center of the space surrounded by the sputtering target <NUM>. At this point in time, the sputtered particle flux <NUM> does not contribute to film formation. When the substrate S moves further, and the sputtered particle flux <NUM> is incident thereon, the sputtered particle flux <NUM> also contributes to film formation, in addition to the sputtered particle flux <NUM>. When the substrate S moves further and reaches the sputtering cathode <NUM>, film formation is similarly carried out by the sputtered particle fluxes <NUM> and <NUM> produced with the sputtering target <NUM> of the sputtering cathode <NUM>. <FIG> shows the situation in which the substrate S has moved further so as to have moved directly above the sputtering cathode assembly. As shown in <FIG>, the sputtered particle fluxes <NUM>, <NUM> produced with the sputtering targets <NUM> of the sputtering cathodes <NUM> and <NUM> are incident on the substrate S, whereby film formation is performed. The substrate S is moved in this manner while film formation is performed. Then, as shown in <FIG>, the substrate S is fully distanced from above the sputtering cathode assembly, moving to a position at which the sputtered particle fluxes <NUM> and <NUM> are not incident on the substrate S. A thin film F is formed on the substrate S in this manner.

Next, a case in which film formation is performed without moving the substrate S, which is to say, a case in which static film formation is performed, will be described.

In this case, it is assumed that the substrate S has a size that covers a plurality of sputtering cathodes, as shown in <FIG>. A shutter (not shown) for preventing the sputtered particle fluxes <NUM>, <NUM> from being incident on the substrate S can be inserted in the space between the substrate S and the sputtering cathodes. At a point in time at which, with the shutter inserted into the space between the substrate S and the sputtering cathodes, stable sputtered particle fluxes <NUM> and <NUM> are produced from the sputtering cathodes, the shutter is moved out of the space between the substrate S and the sputtering cathodes. At this point in time, the sputtered particle fluxes <NUM> and <NUM> are incident on the substrate S, and film formation begins. By performing sputtering in this manner for the required time, a thin film F is formed on the substrate S by way of static film formation. Here, the distance between the opposed target surfaces, the distance between the end of target and the substrate, and the spacing between adjacent cathodes are set to optimum values.

As shown in <FIG>, the sputtering target <NUM> is formed from four plate-shaped sputtering targets <NUM> a, <NUM> b, <NUM> c, and <NUM> d, the permanent magnet <NUM> is formed from four plate-shaped or rod-shaped permanent magnets <NUM> a, <NUM> b, <NUM> c, and <NUM> d, and the yoke <NUM> is formed from four plate-shaped yokes <NUM> a, <NUM> b, <NUM> c, and <NUM> d. Backing plates <NUM> a, <NUM> b, <NUM> c, and <NUM> d are respectively inserted between the sputtering targets <NUM> a, <NUM> b, <NUM> c, and <NUM> d and the permanent magnets <NUM> a, <NUM> b, <NUM> c, and <NUM> d. The distance between the sputtering target <NUM> a and the sputtering target <NUM> c is <NUM>, the distance between the sputtering target <NUM> b and the sputtering target <NUM> d is <NUM>, and the height of the sputtering targets <NUM> a, <NUM> b, <NUM> c, and <NUM> d is <NUM>.

Four plate-shaped anodes <NUM> a, <NUM> b, <NUM> c, and <NUM> d are provided outside of the yokes <NUM> a, <NUM> b, <NUM> c, and <NUM> d. The anodes <NUM> a, <NUM> b, <NUM> c, and <NUM> d are connected to a grounded vacuum vessel, together with an anode <NUM>.

As described above, according to the first embodiment, a plurality of sputtering cathodes having the sputtering target <NUM> with a rectangular tubular shape having a rectangular cross-section, and having erosion surfaces facing inward, are arranged in parallel on a horizontal plane, and the polarities of the permanent magnets <NUM> of two mutually adjacent sputtering cathodes are mutually opposite, the opposite polarities not being part of the invention, whereby the following various advantages can be obtained. That is to say, because sputtering can be performed using a plurality of sputtering cathodes <NUM> arranged in parallel, the thin film F can be formed on a substrate S having a large area, at a high speed. Furthermore, the plasma <NUM> can be generated circulating around the inner surface of the sputtering target <NUM> on the erosion surface side of the sputtering target <NUM>. Therefore, since the density of the plasma <NUM> can be increased, the film forming speed can be sufficiently increased. Further, since the location at which the majority of the plasma <NUM> is generated is limited to the vicinity of the surface of the sputtering
target <NUM>, in combination with the provision of the light blocking shield <NUM>, the possibility of damage occurring due to the irradiation of the substrate S with light emitted from the plasma <NUM> can be minimized. Furthermore, the magnetic force lines generated by the magnetic circuit, which is formed by the permanent magnets <NUM> and the yoke <NUM>, are basically restricted to the sputtering cathode, and moreover, the polarities of the permanent magnets <NUM> of the two mutually adjacent sputtering cathodes are mutually opposite, and the auxiliary magnetic pole <NUM> is provided, the opposite polarities and the auxiliary magnetic pole <NUM> not being part of the invention, whereby, among the magnetic force lines generated by the magnetic circuit, the downwardly oriented magnetic force lines are confined in the space below the sputtering cathode assembly, and are not oriented toward the substrate S, as shown in <FIG>, and there is no risk of the substrate S being damaged by the plasma <NUM> or electron rays. Furthermore, since the film formation is carried out using the sputtered particle fluxes <NUM>, <NUM> produced with the pair of mutually facing long-side portions of the sputtering target <NUM>, damage due to bombardment of the substrate S by reflected high energy particles of the neutral sputtering gas can be minimized. Further, because the sputtered particle fluxes <NUM>, <NUM> produced with the pair of mutually facing long-side portions of the sputtering target <NUM> have a uniform intensity distribution in a direction parallel to the long-side portions, in combination with performing film formation while moving the substrate S at a constant speed in a direction traversing these long-side portions, for example, in a direction perpendicular to these long-side portions, variations in the film thickness of the thin film F formed on the substrate S can be reduced and, for example, variations in the film thickness can be reduced to ±<NUM>% or less. The sputtering device is preferably used in film formation for electrode materials or the like, in the manufacture of various devices such as semiconductor devices, organic solar cells, inorganic solar cells, liquid crystal displays, organic EL displays, films and the like.

The sputtering device according to the second embodiment, which does not form part of the invention, differs from the sputtering device according to the first embodiment in that the sputtering target <NUM> shown in <FIG> is used. That is to say, as shown in <FIG>, the sputtering target <NUM> includes a pair of parallel mutually facing long-side portions and semicircular portions connected to the long-side portions. The permanent magnet <NUM> provided outside the sputtering target <NUM> and the yoke <NUM> provided outside the permanent magnet <NUM> have the same shape as the sputtering target <NUM>. The configuration of the sputtering device is otherwise the same as that of the sputtering device according to the first embodiment.

The film forming method using this sputtering device is the same as that of the first embodiment.

Advantages similar to those of the first embodiment can be obtained with the second embodiment.

<FIG> and <FIG> are a longitudinal sectional view and a plan view showing a sputtering device according to the third embodiment, which is compatible with the invention, and show the configuration in the vicinity of a sputtering cathode assembly provided inside a vacuum vessel of the sputtering device. <FIG> is a cross-sectional view along the line Y-Y in <FIG>.

As shown in <FIG> and <FIG>, in this sputtering device, a plurality of sputtering cathodes are arranged in parallel on a vertical plane, and a sputtering cathode assembly is formed from these sputtering cathodes. The number of sputtering cathodes constituting the sputtering cathode assembly is selected as appropriate, in accordance with the required film forming speed and the like. In <FIG> and <FIG>, only one mutually adjacent pair of sputtering cathodes <NUM> and <NUM> is shown, by way of example, but there is no limitation to this. The spacing between the sputtering cathodes <NUM> and <NUM> is selected as appropriate so that a film can be formed by sputtering, not only with the sputtering cathode <NUM>, but also with the sputtering cathode <NUM>, in the space above the sputtering cathode assembly. If three or more sputtering cathodes constitute the sputtering cathode assembly, the spacing between the sputtering cathodes is generally equal, but this does not necessarily have to be equal, and in such cases, the spacing is selected as required. Other aspects of the sputtering device are the same as those of the first embodiment.

After the vacuum vessel is evacuated to a high vacuum by a vacuum pump, Ar gas is introduced as a sputtering gas into the space surrounded by the sputtering target <NUM>, and a high DC voltage necessary for plasma generation is generally applied between the anode <NUM> and the sputtering cathodes from a predetermined power supply. Generally, the anode <NUM> is grounded and a negative high voltage (for example, -<NUM> V) is applied to the sputtering cathodes. As a result, in the same manner as shown in <FIG> and <FIG>, plasma <NUM> is generated in the vicinity of the surface of the sputtering target <NUM>, circulating along the inner surface of the sputtering target <NUM>.

As a result of sputtering of the sputtering target <NUM> with Ar ions in the plasma <NUM> circulating along the inner surface of the sputtering target <NUM> of each sputtering cathode, atoms comprised by the sputtering target <NUM> are ejected upward from the space surrounded by the sputtering targets <NUM>. At this time, atoms are ejected from all parts of the erosion surface of the sputtering target <NUM> near the plasma <NUM>, but atoms that are ejected from the erosion surface of the short side portions of the inside of the sputtering target <NUM> are essentially not used for film formation. Therefore, horizontal shielding plates may be provided above the sputtering target <NUM> so as to shield both end portions, in the long side direction, of the sputtering target <NUM>, so that atoms ejected from the erosion surfaces of the short-side portions of the sputtering target <NUM> do not reach the substrate S during film formation. Alternatively, the width b of the sputtering target <NUM> in the longitudinal direction may be made sufficiently greater than the width of the substrate S, so that atoms ejected from the erosion surface of the short-side portion of the sputtering target <NUM> do not reach the substrate S during film formation. In the same manner as shown in <FIG>, as a result of some of the atoms ejected from the sputtering target <NUM> being shielded by the light blocking shields <NUM>, sputtered particle fluxes <NUM>, <NUM> are produced from the erosion surface of the long-side portions of the sputtering target <NUM>. The sputtered particle fluxes <NUM>, <NUM> have substantially uniform intensity distributions in the longitudinal direction of the sputtering target <NUM>.

When stable sputtering particle fluxes <NUM>, <NUM> are produced from the sputtering cathodes, a film is formed by the sputtered particle fluxes <NUM>, <NUM>, while moving the substrate S with respect to the sputtering targets <NUM>, at a constant speed, in the direction traversing the long-side portions of the sputtering targets <NUM>. When the substrate S moves above the space surrounded by the sputtering target <NUM>, first, the sputtered particle flux <NUM> is incident on the substrate S, and film formation begins. At the point in time when the leading edge of the substrate S has approached above the vicinity of the center of the space surrounded by the sputtering target <NUM>, the sputtered particle flux <NUM> does not contribute to film formation. When the substrate S moves further, and the sputtered particle flux <NUM> is incident thereon, the sputtered particle flux <NUM> also contributes to film formation, in addition to the sputtered particle flux <NUM>. When the substrate S is moved directly above the space surrounded by the sputtering target <NUM>, the sputtered particle fluxes <NUM>, <NUM> are incident on the substrate S, whereby film formation is performed. The substrate S is moved further in this manner while film formation is performed. Then, the substrate S is fully distanced from above the space surrounded by the sputtering target <NUM>, moving to a position at which the sputtered particle fluxes <NUM> and <NUM> are not incident on the substrate S. A thin film F is formed on the substrate S in this manner.

According to the third embodiment, a plurality of sputtering cathodes having the sputtering target <NUM> with a rectangular tubular shape having a rectangular cross-section, and having erosion surfaces facing inward are arranged in parallel on a vertical plane, and the polarities of the permanent magnets <NUM> of two mutually adjacent sputtering cathodes are mutually opposite, the opposite polarities not being part of the invention, whereby the following various advantages can be obtained. That is to say, because sputtering can be performed using a plurality of sputtering cathodes arranged in parallel on a vertical plane, the thin film F can be formed on the substrate S, at a high speed. Furthermore, the plasma <NUM> can be generated circulating around the inner surface of the sputtering target <NUM> on the erosion surface side of the sputtering target <NUM>. Therefore, since the density of the plasma <NUM> can be increased, the film forming speed can be sufficiently increased. Further, since the location at which the majority of the plasma <NUM> is generated is limited to the vicinity of the surface of the sputtering target <NUM>, in combination with the provision of the light blocking shield <NUM>, the possibility of damage occurring due to the irradiation of the substrate S with light emitted from the plasma <NUM> can be minimized. Furthermore, the magnetic force lines generated by the magnetic circuit, which is formed by the permanent magnets <NUM> and the yoke <NUM>, are basically restricted to the sputtering cathode, and moreover, the polarities of the permanent magnets <NUM> of the two mutually adjacent sputtering cathodes are mutually opposite, and the auxiliary magnetic pole <NUM> is provided, the opposite polarities and the auxiliary magnetic pole <NUM> not being part of the invention, whereby, among the magnetic force lines generated by the magnetic circuit, the downwardly oriented magnetic force lines are confined to the space in the vicinity of the sputtering cathode assembly, and are not oriented toward the substrate S, as shown in <FIG>, and there is no risk of the substrate S being damaged by the plasma <NUM> or electron rays. Furthermore, since the film formation is carried out using the sputtered particle fluxes <NUM>, <NUM> produced with the pair of mutually facing long-side portions of the sputtering target <NUM>, damage due to bombardment of the substrate S by reflected high energy particles of the neutral sputtering gas can be minimized. Further, because the sputtered particle fluxes <NUM>, <NUM> produced with the pair of mutually facing long-side portions of the sputtering target <NUM> have a uniform intensity distribution in a direction parallel to the long-side portions, in combination with performing film formation while moving the substrate S at a constant speed in a direction traversing these long-side portions, for example, in a direction perpendicular to these long-side portions, variations in the film thickness of the thin film F formed on the substrate S can be reduced and, for example, variations in the film thickness can be reduced to ±<NUM>% or less. The sputtering device is preferably used in film formation for electrode materials or the like, in the manufacture of various devices such as semiconductor devices, organic solar cells, inorganic solar cells, liquid crystal displays, organic EL displays, films and the like.

<FIG> and <FIG> are a longitudinal sectional view and a plan view showing a sputtering device according to the fourth embodiment, which does not form part of the invention, and show the configuration in the vicinity of a sputtering cathode provided inside a vacuum vessel of the sputtering device. <FIG> is a cross-sectional view along the line Z-Z in <FIG>. <FIG> is a cross-sectional view along the line W-W in <FIG>.

As shown in <FIG>, <FIG> and <FIG>, the sputtering device has the sputtering target <NUM> having a rectangular tubular shape having a rectangular cross-sectional shape (or angular ring shape), and having erosion surfaces facing inward. A pair of mutually facing long-side portions of the sputtering target <NUM> each comprises cylindrical rotary targets <NUM>, <NUM>, and a pair of mutually facing short-side portions <NUM>, <NUM> of the sputtering target <NUM> each have a rectangular cross-sectional shape. The rotary targets <NUM> and <NUM> are provided so as to be rotatable about the central axes thereof by a non-illustrated rotation mechanism. Specifically, the rotary targets <NUM> and <NUM> are provided with rotary shafts <NUM> a and <NUM> a at both ends thereof, and the rotary targets <NUM> and <NUM> are rotated as a result of the rotary shafts <NUM> a and <NUM> a being rotated by the rotation mechanism. The rotational directions of the rotary targets <NUM> and <NUM> may be the same as, or opposite to, each other, and are selected as necessary. This is configured so that cooling water can flow through the interior of the rotary cathodes <NUM>, <NUM> allowing the rotary cathodes <NUM>, <NUM> to be cooled during use. The short-side portions <NUM>, <NUM> have heights that are approximately the same as the diameter of the rotary targets <NUM>, <NUM>, for example. Both ends of the short-side portions <NUM>, <NUM> facing the rotary targets <NUM>, <NUM> are concavely rounded, corresponding to the cylindrical shape of the rotary targets <NUM>, <NUM>, and are close thereto, to an extent such as does not present a hindrance to the rotation of the rotary targets <NUM>, <NUM>. Permanent magnets <NUM> and <NUM> are provided at the interior of the rotary targets <NUM>, <NUM> at positions parallel to the central axis and radially offset from the central axis. The permanent magnets <NUM> and <NUM> have a rectangular cross-sectional shape, the long sides of which are perpendicular to the radial direction of the rotary targets <NUM> and <NUM>. As shown in <FIG>, where the angle of inclination of the short sides of the cross-sectional shape of the permanent magnets <NUM>, <NUM>, with respect to the plane including the central axis of the rotary targets <NUM>, <NUM>, is θ, θ is <NUM> degrees or more and less than <NUM> degrees, and the angle of inclination can be set to an any angle within this range so as to achieve a good balance between increased film forming speed and low damage. In <FIG>, a case in which θ=<NUM> degrees is shown as one example. The permanent magnets <NUM> and <NUM> are fixed to a member that is independent of the rotary targets <NUM> and <NUM> so that, when the rotary targets <NUM> and <NUM> rotate, they do not rotate together therewith. The polarities of the permanent magnets <NUM> and <NUM> are as shown in <FIG>, but may be opposite, the opposite polarities not being part of the invention. The permanent magnets <NUM> are provided on the outside of the pair of mutually facing short-side portions <NUM> and <NUM> of the sputtering target <NUM>, and the yokes <NUM> are provided on the outside of the permanent magnets <NUM>. The polarities of the permanent magnets <NUM> are as shown in <FIG>, but the polarities may also be respectively the exact opposites, the opposite polarities not being part of the invention. The sputtering targets <NUM>, the permanent magnets <NUM>, <NUM> and <NUM>, and the yokes <NUM> form a sputtering cathode. The sputtering cathode is generally fixed to the vacuum vessel in an electrically insulated manner A magnetic circuit is formed by the permanent magnets <NUM>, <NUM>, provided inside the rotary targets <NUM> and <NUM>, the permanent magnets <NUM>, and the yokes <NUM>. Cooling backing plates are preferably provided between the short-side portions <NUM>, <NUM> and the permanent magnets <NUM>, and cooling water, for example, flows in flow paths provided inside the backing plates. An anode <NUM> is provided in the vicinity of the lower end of the space surrounded by the sputtering target <NUM> so that the erosion surface of the sputtering target <NUM> is exposed. This anode <NUM> is generally connected to the grounded vacuum vessel. Furthermore, a light blocking shield <NUM> having an L-shaped cross-section is provided in the vicinity of the upper end of the space surrounded by the sputtering target <NUM> so that the erosion surface of the sputtering target <NUM> is exposed. The light blocking shield <NUM> is formed from a conductor, and typically from a metal. The light blocking shield <NUM> also serves as an anode and is generally connected to the grounded vacuum vessel, in the same manner as the anode <NUM>. The other aspects are the same as those of the first embodiment.

The film forming method using this sputtering device is the same as that of the first embodiment, except that sputtering is performed while rotating the rotary targets <NUM>, <NUM> constituting the pair of mutually facing long-side portions of the sputtering target <NUM>.

According to the fourth embodiment, in addition to the advantages similar to those of the first embodiment, the pair of mutually facing long-side portions of the sputtering target <NUM> comprise the rotary targets <NUM>, <NUM>, which allows for advantages in that the usage efficiency of the sputtering target <NUM> is high and film formation costs can be reduced.

As shown in <FIG>, the sputtering device according to the fifth embodiment, which does not form part of the invention, differs from the fourth embodiment in that both ends of the rotary targets <NUM>, <NUM> are chamfered (the chamfer angle is, for example, <NUM> degrees with respect to the central axis of the rotary targets <NUM>, <NUM>), and both ends of the short-side portions <NUM>, <NUM> are also correspondingly chamfered at an angle. The other aspects are the same as those of the fourth embodiment.

The film forming method using this sputtering device is the same as that of the fourth embodiment.

Advantages similar to those of the fourth embodiment can be obtained with the fifth embodiment.

<FIG> and <FIG> are a longitudinal sectional view and a plan view showing a sputtering device according to a sixth embodiment, which does not form part of the invention, and show the configuration in the vicinity of a sputtering cathode provided inside a vacuum vessel of the sputtering device. <FIG> is a cross-sectional view along the line V-V in <FIG>.

As shown in <FIG> and <FIG>, in this sputtering device, two of the sputtering targets <NUM> of the sputtering device according to the fourth embodiment are united, with one rotary target being shared, such that the sputtering targets are configured to have three rotary targets <NUM>, <NUM>, <NUM>. The rotational directions of these rotary targets <NUM>, <NUM>, <NUM> may be the same as, or opposite to, each other, and are selected as necessary. The other aspects are the same as those of the fourth embodiment. Note that four rotary targets may be united, or five or more rotary targets may be united.

According to the sixth embodiment, in addition to the advantages similar to those of the fourth embodiment, advantages are possible in that film formation can be performed efficiently on a substrate S having a large area, and static film formation can also easily be performed. This sixth embodiment is particularly suitable for use in forming an electrode film adjacent to a silicon power generation layer or an organic power generation layer in the manufacture of a device such as a heterojunction silicon solar cell or an organic EL display.

<FIG> is a longitudinal sectional view showing a sputtering device according to a seventh embodiment, which is an embodiment of the invention, and shows the configuration in the vicinity of a sputtering cathode provided inside a vacuum vessel of the sputtering device. Furthermore, <FIG> is a perspective view showing the sputtering target <NUM>.

As shown in <FIG> and <FIG>, the sputtering device has the sputtering target <NUM> having a rectangular tubular shape having a rectangular cross-sectional shape (or angular ring shape), and having erosion surfaces facing inward. A permanent magnet assembly <NUM> is provided on the outside of the sputtering target <NUM>, and a yoke <NUM> is provided on the outside of the permanent magnet assembly <NUM>. The sputtering target <NUM>, the permanent magnet assembly <NUM>, and the yoke <NUM> form a sputtering cathode. A pair of mutually facing long-side portions <NUM> a and <NUM> b of the sputtering target <NUM> are formed as mutually parallel flat plates. In contrast, a pair of mutually facing short-side portions <NUM> c and <NUM> d of the sputtering target <NUM> have shapes which are curved, with respect to a plane or curve including the pair of long-side portions <NUM> a and <NUM> b, forming a curved surface in which the erosion surface is twisted, from one side of the long-side portions <NUM> a, <NUM> b, resulting in a shape in central portions C <NUM> and C <NUM> of the short sides <NUM> c, <NUM> d which is perpendicular to the long-side portions <NUM> a and <NUM> b, in other words, which lies in a horizontal plane, and further extending to the other side of the long-side portions <NUM> a, <NUM> b, forming a curved surface in which the erosion surface is twisted. Other aspects are the same as those of the sputtering cathode in the first embodiment.

According to the seventh embodiment, in addition to advantages similar to those of the first embodiment, since the sputtering target <NUM> is formed in the shape described above, advantages are possible in that, when film formation is performed with the short-side portions <NUM> c, <NUM> d arranged in the horizontal direction, foreign matter generated during film formation can be prevented from being deposited on the short-side portions <NUM> c, <NUM> d.

In the eighth embodiment, which is an embodiment of the invention, a pulse power source is used as a power source for applying a voltage required for sputtering between the sputtering cathode and the anode, in the sputtering devices according to the first to seventh embodiments. The voltage pulse waveform of this pulse power supply is shown in <FIG>. As shown in <FIG>, in this pulse power supply, a voltage pulse of <NUM> V, or a negative voltage V<NUM>-, the absolute value of which is about <NUM> V or less, is applied at a high level, and a negative voltage VL-, the absolute value of which is about <NUM> V or more, is applied at a low level, so that a positive voltage is not applied. By using a pulse waveform for the voltage applied to the sputtering cathode, some or all of the glow discharge during sputtering can be prevented from becoming an arc discharge.

According to the eighth embodiment, by using a pulse power supply that generates a voltage pulse having the waveform described above, the following advantages are possible. That is to say, according to the findings of the present inventor, if the high level of the voltage pulse is a positive voltage, damage is likely to occur to the substrate S and the thin film F formed on the substrate S, during film formation, as a result of bombarding the substrate S with Ar+ generated from the Ar gas that is used as a sputtering gas, but by not applying a positive voltage, with a high level voltage pulse of <NUM> V, or a negative voltage V<NUM>-, the absolute value of which is about <NUM> V or less, and a low level voltage pulse of a negative voltage VL-, the absolute value of which is about <NUM> V or more, such problems can be eliminated, and a high quality thin film F can be formed without damage. The eighth embodiment is particularly suitable for use in forming an electrode film adjacent to an organic film in the manufacture of an organic device such as an organic solar cell or an organic EL display.

Embodiments and examples of this invention have been specifically described above, but this invention is not limited to the aforementioned embodiments and examples, and various modifications are possible based on the technical ideas of this invention.

For example, the numerical values, materials, structures, shapes, and the like given in the aforementioned embodiments and examples are merely examples, and numerical values, materials, structures, shapes, and the like different from these may be used as necessary.

Claim 1:
A sputtering cathode (<NUM>, <NUM>) having a sputtering target (<NUM>), wherein the sputtering target has a rectangular tubular shape, wherein the sputtering target has a rectangular or angular-ring cross-sectional shape, wherein the sputtering target has a pair of mutually facing long-side portions and a pair of mutually facing short-side portions, and has an erosion surface facing inward, a magnetic circuit being provided along the sputtering target (<NUM>), wherein:
the pair of long-side portions are formed as mutually parallel flat plates;
the pair of short-side portions are formed as plates continuous with the pair of long-side portions; and
at least one of the short-side portions in the pair of short-side portions is curved, forming a curved surface in which the erosion surface is twisted from the one long-side portion side of the pair of long-side portions, resulting in a shape in the central portion of the one short-side portion which is perpendicular to the pair of long-side portions, and is further curved, forming a curved surface in which the erosion surface is twisted, having a shape extending to the other long-side portion of the pair of long-side portions.