Film forming method and film forming apparatus

Abstract

To suppress damage to a film deposition ground layer.SOLUTION: A film deposition method for sputtering and depositing a film on a substrate using a plurality of rotary targets including a magnet rotatable around a central axis in the inside comprises: arranging the plurality of rotary targets so that central axes parallel to each other are parallel to the substrate; positioning the plurality of rotary targets so as to face the magnets on the opposite side of the substrate from the inside when using a side on witch a line radially extending from the central axis intersects the substrate as the substrate side of a target surface and using the side opposite to the substrate side as the side opposite to the substrate side of the target surface; rotating the respective magnets of the plurality of rotary targets around the central axis while inputting electrical discharge power into the plurality of rotary targets to move the magnets so as to face the substrate side from the inside; and sputtering and depositing a film on the substrate in the state where the magnets avoid a reference position closest to the substrate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a film forming method and a film forming apparatus. [Background technology]

[0002] In electronic devices such as organic light-emitting elements, electrons are injected from a cathode electrode into a light-emitting layer, and holes are injected from an anode electrode, and the electrons and holes are recombined in the light-emitting layer to generate light. Here, there is a technique for forming an extremely thin, light-transmitting metal layer by a sputtering method as the electrode layer (cathode layer) of an organic light-emitting element in order to increase the light transmittance of the light emitted in the light-emitting layer (see, for example, Patent Document 1). Alternatively, there is a technique for using a transparent conductive oxide layer with excellent light transmittance as the material for the electrode layer (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-317384 A [Patent Document 2] JP 2002-343555 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when an electrode layer is formed on an underlayer by sputtering, the underlayer may be damaged. In particular, since the underlayer is made of an organic material, if the underlayer is damaged, the characteristics of the electronic device may be deteriorated.

[0005] In view of the above circumstances, an object of the present invention is to provide a film formation method and a film formation apparatus that suppresses damage to an underlying layer when an electrode layer is formed on the underlying layer by a sputtering method. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one embodiment of the present invention provides a film formation method for performing sputtering film formation on a substrate using a plurality of rotary targets each having a central axis and a target surface, and each having a magnet inside that can rotate around the central axis. In the film forming method, the multiple rotary targets are arranged such that the central axes are parallel to each other and parallel to the substrate. In each of the plurality of rotary targets, when a side where a line extending radially from the central axis intersects with the substrate is defined as a substrate side of the target surface, and a side opposite to the substrate side is defined as an anti-substrate side of the target surface, The magnet is positioned so as to face the opposite side of the substrate from the inside, and discharge power is applied to the rotary targets; While supplying the discharge power to the rotary targets, the magnets of the rotary targets are rotated about the central axis, so that the magnets move from the inside to face the substrate side; Sputtering deposition is performed on the substrate while avoiding the reference position where the magnet is closest to the substrate.

[0007] According to such a film formation method, when the electrode layer is formed on the underlayer by a sputtering method, damage to the underlayer is suppressed. Furthermore, in order to more appropriately suppress damage to the underlayer, the following film formation method may be applied.

[0008] In the above film formation method, if the rotation angle of the magnet when the magnet is located at the reference position is defined as 0 degrees, and rotating the magnet in a counterclockwise direction is defined as a positive rotation angle, the rotation angle of the magnet from the reference position may be set in the range of 30 degrees to 90 degrees, or in the range of -30 degrees to -90 degrees, and sputtering film formation may be performed on the substrate.

[0009] In the film formation method, the supply of the discharge power to the rotary targets may be cut off when the absolute value of the rotation angle is less than 30 degrees.

[0010] In the above film formation method, when the magnet is opposed to the opposite side of the substrate from the inside and discharge power is supplied to the multiple rotary targets, the rotation angle may be set in the range of 100 degrees to 260 degrees.

[0011] In the above-mentioned film formation method, a discharge power when the magnet is caused to face the opposite side of the substrate from the inside may be set to be smaller than a discharge power when sputtering film formation is performed on the substrate.

[0012] In the above-mentioned film formation method, when sputtering film formation is performed on the substrate, among the plurality of rotary targets, the magnets of adjacent rotary targets may be rotated in the same direction.

[0013] In the above-mentioned film formation method, when sputtering film formation is performed on the substrate, among the plurality of rotary targets, the magnets of adjacent rotary targets may be rotated in opposite directions.

[0014] In the above film formation method, sputtering film formation may be performed on the substrate at least once when the rotation angle is in the range of 30 degrees to 90 degrees and at least once when the rotation angle is in the range of -30 degrees to -90 degrees.

[0015] In the above film formation method, sputtering film formation may be performed on the substrate at least once by oscillating the magnet through a rotation angle range of 30 degrees to 90 degrees, and at least once by oscillating the magnet through a rotation angle range of -30 degrees to -90 degrees.

[0016] In order to achieve the above object, a film forming apparatus according to one aspect of the present invention comprises: A substrate holder for supporting a substrate; A plurality of rotary targets as described above; a power source that supplies discharge power to each of the plurality of rotary targets; The rotary target is provided with a control device that controls the discharge power input to each of the rotary targets and the rotation of the magnet. The control device includes: In each of the plurality of rotary targets, when a side where a line extending radially from the central axis intersects with the substrate is defined as a substrate side of the target surface, and a side opposite to the substrate side is defined as an anti-substrate side of the target surface, The magnet is positioned so as to face the opposite side of the substrate from the inside, and discharge power is applied to the rotary targets; While supplying the discharge power to the rotary targets, the magnets of the rotary targets are rotated about the central axis to move the magnets from the inside to face the substrate side; The magnet is controlled to perform sputtering deposition on the substrate while avoiding the reference position where the magnet is closest to the substrate.

[0017] According to such a film forming apparatus, when an electrode layer is formed on a base layer by a sputtering method, damage to the base layer is suppressed. Furthermore, in order to more appropriately suppress damage to the base layer, the following film forming apparatus may be applied.

[0018] In the film formation apparatus, if the rotation angle of the magnet when the magnet is located at the reference position is defined as 0 degrees, and rotating the magnet in a counterclockwise direction is defined as a positive rotation angle, the rotation angle of the magnet from the reference position may be set in the range of 30 degrees to 90 degrees, or in the range of -30 degrees to -90 degrees, and sputtering film formation may be performed on the substrate.

[0019] In the film formation apparatus, the supply of the discharge power to the rotary targets may be cut off when the absolute value of the rotation angle is less than 30 degrees.

[0020] In the film formation apparatus, the magnet may be opposed to the opposite side of the substrate from the inside, and the rotation angle may be set in the range of 100 degrees to 260 degrees when discharge power is supplied to the multiple rotary targets.

[0021] In the film formation apparatus, a discharge power when the magnet is caused to face the opposite side of the substrate from the inside may be set to be smaller than a discharge power when sputtering film formation is performed on the substrate.

[0022] In the film formation apparatus, when sputtering film formation is performed on the substrate, the magnets of adjacent rotary targets among the plurality of rotary targets may be rotated in the same direction.

[0023] In the film formation apparatus, when sputtering film formation is performed on the substrate, the magnets of adjacent rotary targets among the plurality of rotary targets may be rotated in opposite directions.

[0024] In the film formation apparatus, sputtering film formation may be performed on the substrate at least once when the rotation angle is in the range of 30 degrees to 90 degrees and at least once when the rotation angle is in the range of -30 degrees to -90 degrees.

[0025] In the film formation apparatus, sputtering film formation may be performed on the substrate at least once by oscillating the magnet through a rotation angle range of 30 degrees to 90 degrees, and at least once by oscillating the magnet through a rotation angle range of -30 degrees to -90 degrees. Effect of the Invention

[0026] As described above, according to the present invention, when an electrode layer is formed on an underlying layer by sputtering, a film formation method and a film formation apparatus are provided that suppress damage to the underlying layer. [Brief description of the drawings]

[0027] [Figure 1] 1 is a schematic cross-sectional view showing an organic light-emitting element of the present embodiment. [Diagram 2] FIG. 1 is a schematic cross-sectional view showing an example of a film forming apparatus according to an embodiment of the present invention. [Diagram 3] 10 is a diagram for explaining the definition of the angle of a magnet that rotates around the central axis of a rotary target. FIG. [Figure 4] FIG. 2 is a schematic plan view showing an example of a film forming apparatus according to the present embodiment. [Diagram 5] 1A to 1C are schematic cross-sectional views showing a film forming method according to an embodiment of the present invention. [Figure 6] 1A to 1C are schematic cross-sectional views showing a film forming method according to an embodiment of the present invention. [Figure 7] 1A to 1C are schematic cross-sectional views showing a film forming method according to an embodiment of the present invention. [Figure 8] Figure (a) is a schematic cross-sectional view showing a state when sputtering is performed on a substrate once when the magnet rotation angle θ is in the range of 30 degrees to 90 degrees and once when it is in the range of -30 degrees to -90 degrees, using adjacent rotary targets. Figure (b) is a conceptual graph showing the film thickness distribution of the cathode layer formed on a substrate when sputtering is performed on a substrate once when the magnet rotation angle θ is in the range of 30 degrees to 90 degrees and once when it is in the range of -30 degrees to -90 degrees. [Figure 9] 1 is a schematic cross-sectional view showing a first modified example of the film forming method of the present embodiment. [Figure 10] 1 is a schematic cross-sectional view showing a first modified example of the film forming method of the present embodiment. [Figure 11] Figure (a) is a graph showing the emission intensity versus the magnet rotation angle θ, and Figure (b) is a graph showing the deposition rate (nm / min) versus the magnet rotation angle θ. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, XYZ axis coordinates may be introduced. In addition, the same reference numerals may be given to the same components or components having the same functions, and after the components are described, the description may be omitted as appropriate. In addition, the numerical values ​​shown below are examples and are not limited to these examples.

[0029] Fig. 1 is a schematic cross-sectional view showing an organic light-emitting element according to the present embodiment, in which a main part of a top-emission type organic light-emitting element 5 is shown as an example.

[0030] The organic light-emitting element 5 includes an emission layer (EML) 510, an electron transport layer (ETL) 521, a hole transport layer (HTL) 522, an electron injection layer (EIL) 531, a hole injection layer (HIL) 532, a cathode layer 541, and an anode layer 542. In the organic light-emitting element 5, the hole injection layer 532, the hole transport layer 522, the emission layer 510, the electron transport layer 521, and the electron injection layer 531 are laminated in this order from the anode layer 542 toward the cathode layer 541.

[0031] The light-emitting layer 510 is provided between the cathode layer 541 and the anode layer 542. The electron injection layer 531 is provided between the cathode layer 541 and the light-emitting layer 510. The hole injection layer 532 is provided between the anode layer 542 and the light-emitting layer 510. The electron transport layer 521 is provided between the electron injection layer 531 and the light-emitting layer 510. The hole transport layer 522 is provided between the hole injection layer 532 and the light-emitting layer 510.

[0032] In the organic light-emitting element 5, light emitted in the light-emitting layer 510 is extracted from the cathode layer 541. A support substrate (not shown) that supports the organic light-emitting element 5 is disposed on the opposite side of the cathode layer 541, i.e., below the anode layer 542. Thin film transistors, circuits such as wiring, an interlayer insulating layer, and the like are disposed on the substrate (none of which are shown). The support substrate may be a flexible substrate or a non-flexible plate-like substrate.

[0033] The cathode layer 541 is composed of a conductive layer having excellent light transparency and low resistance. The cathode layer 541 is a sputtering layer (also called a sputtering film) formed under a reduced pressure atmosphere, and has a thickness of more than 10 nm and not more than 20 nm, preferably 15 nm or more and not more than 20 nm. The material of the cathode layer 541 contains at least one of Ag and Al. The material of the cathode layer 541 may contain a first component containing at least one of Ag and Al, and a second component containing at least one of Mg, Li, and Ca.

[0034] Furthermore, if the cathode layer 541 is composed only of the above-mentioned metal layer, the thickness is 20 nm or less, which limits the resistance reduction and mechanical strength of the cathode layer 541. To compensate for this, a transparent conductive layer composed of a transparent conductive oxide may be formed by sputtering on the metal layer. Transparent conductive oxides have excellent light transmittance and conductivity. Examples of transparent conductive oxides include ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide). In this case, the cathode layer 541 has a two-layer structure composed of a metal layer / transparent conductive oxide layer in this order from the base.

[0035] The electron injection layer 531 includes at least one of an alkali metal, an alkaline earth metal, an alkali metal fluoride, an alkaline earth metal fluoride, and a lanthanoid. For example, the electron injection layer 531 includes at least one of LiF, CsF, NaF, Ca, Ba, and Yb. The thickness of the electron injection layer 531 is configured to be extremely thin in order to enhance light transmission, and is, for example, 5 nm or more and 10 nm or less.

[0036] When a voltage is applied between the anode layer 542 and the cathode layer 541, holes are injected from the hole injection layer 532 to the hole transport layer 522, and electrons are injected from the electron injection layer 531 to the electron transport layer 521. Then, the holes that have moved through the hole transport layer 522 and the electrons that have moved through the electron transport layer 521 recombine in the light emitting layer 510, and light is generated in the light emitting layer 510. The light generated in the light emitting layer 510 is emitted from the light emitting layer 510 to each of the anode layer 542 and cathode layer 541 sides.

[0037] The organic light-emitting element 5 is a top-emission type, and the hole injection layer 532, the hole transport layer 522, the light-emitting layer 510, the electron transport layer 521, the electron injection layer 531, and the cathode layer 541 are configured to have high light transmittance for emitted light. In addition, the anode layer 542 is configured to reflect the emitted light. As a result, the emitted light that travels directly from the light-emitting layer 510 toward the cathode layer 541 and the emitted light that is reflected by the anode layer 542 are combined, and the emitted light in the organic light-emitting element 5 passes through the cathode layer 541 and is emitted to the outside of the organic light-emitting element 5.

[0038] Here, when the cathode layer 541 is formed on the electron injection layer 531, it is preferable that no damage is caused to the organic material layers below the cathode layer 541, that is, the electron injection layer 531, the electron transport layer 521, the light-emitting layer 510, the hole transport layer 522, and the hole injection layer 532. If these organic material layers are damaged, the light-emitting characteristics or electrical characteristics of the organic light-emitting element 5 may deteriorate.

[0039] In this embodiment, a magnetron sputtering method is introduced as a method for forming the cathode layer 541, and a film forming method and a film forming apparatus are provided that are less likely to cause damage from the cathode layer 541 to an underlying organic material layer. Furthermore, a film forming method and a film forming apparatus that exhibit excellent characteristics in the film thickness distribution of the cathode layer 541 are provided.

[0040] 2(a) and (b) are schematic cross-sectional views showing an example of a film forming apparatus according to the present embodiment. Fig. 2(a) shows a schematic cross-sectional view showing the arrangement of a plurality of rotary targets and a substrate in the film forming apparatus 1, and Fig. 2(b) shows a schematic plan view showing the arrangement.

[0041] A magnetron sputtering apparatus is exemplified as the film forming apparatus 1 of this embodiment. In the film forming apparatus 1, at least two or more of a plurality of rotatable cylindrical rotary targets are used to perform sputtering film formation (magnetron sputtering) on ​​the substrate 10. For example, ten rotary targets 201-210 are illustrated in Figs. 2(a) and (b). The number of the plurality of rotary targets is not limited to this number and may be appropriately changed according to, for example, the size of the substrate 10. It is assumed that the substrate 10 is provided with an underlayer (organic material layer) below the cathode layer 541.

[0042] Each of the rotary targets 201-210 has a central axis 20 and a target surface (sputtering surface) 21. Each of the rotary targets 201-210 has a magnet therein that can rotate around the central axis 20. For example, in the example of FIGS. 2(a) and 2(b), magnets 301-310 are arranged in the order of the rotary targets 201-210. The magnets 301-310 are so-called magnet assemblies. The magnets 301-310 have permanent magnets and magnetic yokes. The film forming apparatus 1 is provided with a rotation mechanism (not shown) that rotates the rotary targets 201-210 and the magnets 301-310.

[0043] The multiple rotary targets 201-210 are arranged such that their central axes 20 are parallel to each other and to the substrate 10. For example, the multiple rotary targets 201-210 are arranged side by side at equal intervals such that their target surfaces 21 face each other in a direction intersecting the central axis 20. The direction in which the multiple rotary targets 201-210 are arranged side by side corresponds to the longitudinal direction of the substrate 10. Note that the direction in which the multiple rotary targets 201-210 are arranged side by side may be the lateral direction of the substrate 10, if necessary.

[0044] The substrate 10 is supported by a substrate holder (not shown). The potential of the substrate holder is, for example, a floating potential, a ground potential, or the like. The multiple rotary targets 201-210 are arranged such that the direction in which the multiple rotary targets 201-210 are arranged is parallel to the longitudinal direction of the substrate 10. The target surface 21 of each of the multiple rotary targets 201-210 faces the film formation surface 11 of the substrate 10.

[0045] In Figures 2(a) and (b), the direction in which the multiple rotary targets 201-210 are arranged side by side corresponds to the Y-axis direction, the direction from the substrate 10 toward the multiple rotary targets 201-210 corresponds to the Z-axis, and the direction in which each of the multiple rotary targets 201-210 extends corresponds to the X-axis.

[0046] Furthermore, when the multiple rotary targets 201-210 and the substrate 10 are viewed in the Z-axis direction, the pair of rotary targets 201, 210 arranged at both ends in the Y-axis direction are arranged so as to protrude from the substrate 10. For example, the multiple rotary targets 201-210 and the substrate 10 are arranged so that at least a portion of each of the pair of rotary targets 201, 210 overlaps with the substrate 10.

[0047] 2(a) and (b), the central axis 20 of the rotary target 201 overlaps with the end 12a of the substrate 10 in the Y-axis direction in the Z-axis direction. Also, the central axis 20 of the rotary target 210 overlaps with the end 12b of the substrate 10 in the Y-axis direction.

[0048] The rotary targets 201 to 210 are arranged at approximately equal pitches in the Y-axis direction. The relative distance between the rotary targets 201 to 210 and the substrate 10 during sputtering deposition is fixed.

[0049] The material of the rotary targets 201-210 is, for example, the material that constitutes the cathode layer 541. The substrate 10 is, for example, an organic resin sheet including an organic material layer below the cathode layer 541, or a glass plate including the organic material layer.

[0050] In this embodiment, discharge power is applied to each of the multiple rotary targets 201-210, and the magnets of each of the multiple rotary targets 201-210 rotate around the central axis 20 to form a film on the substrate 10 by sputtering.

[0051] The same power is applied to each of the multiple rotary targets 201-210 to ensure that each rotary target is consumed approximately evenly. The applied power may be DC power or AC power in the RF band, VHF band, or the like. Each of the multiple rotary targets 201-210 can rotate clockwise or counterclockwise. Each of the multiple rotary targets 201-210 rotates clockwise or counterclockwise during film formation.

[0052] 3 is a diagram for explaining the definition of the angle of the magnet that rotates around the central axis of the rotary target. In FIG. 3, the rotary target 202 is illustrated as an example among the multiple rotary targets 201 to 210. The magnet angle, positive angle, negative angle, and reference position A (described later) are defined in the same manner as for the rotary target 202 for the rotary targets 201, 203 to 210 other than the rotary target 202, that is, for each of the multiple rotary targets 201, 203 to 210. Note that an adhesion prevention plate 411, not shown in FIG. 2(a), is disposed on the opposite side of the substrate 10 with the rotary target 202 in between.

[0053] Regarding the rotation angle θ of magnet 302, the angle of magnet 302 when the distance between the center of magnet 302 and substrate 10 is shortest is defined as 0 degrees. For example, if a perpendicular line is drawn from central axis 20 to film formation surface 11 of substrate 10, the position where this perpendicular line coincides with center 30 of magnet 302 corresponds to an angle of 0 degrees of magnet 302. When magnet 302 rotates about central axis 20, center 30 describes an arc orbit. When the angle is 0 degrees, magnet 310 is closest to substrate 10, and the position on the arc at this time is defined as reference position A.

[0054] In other words, at reference position A, magnet 302 is closest to substrate 10. When magnet 302 is located at reference position A, the rotation angle θ of magnet 302 is 0 degrees. Regarding the positive and negative angles of magnet 302, a direction in which magnet 302 rotates counterclockwise from 0 degrees is defined as a positive rotation angle (+θ), and a direction in which magnet 302 rotates clockwise is defined as a negative rotation angle (-θ). The position of magnet 302 is defined as the angular position of center 30 at a certain angle.

[0055] In addition, in this embodiment, for each of the multiple rotary targets 201-210, the side where a line 25 radiating from the central axis 20 intersects with the substrate 10 is the substrate side 211 of the target surface 21, and the side opposite the substrate side 211 is the anti-substrate side 212 of the target surface 21.

[0056] By rotating the magnet 302 around the central axis 20 of the rotary target 202, plasma can be concentrated near the target surface 21 that the magnet 302 faces during magnetron discharge. Sputtering particles can be preferentially emitted from the target surface 21 that the magnet 302 faces. This makes it possible to control the direction in which the sputtering particles are emitted from the target surface 21 according to the angle of the magnet 302. Note that in the magnet 302, the south pole and the north pole surrounding the south pole face the rotary target 202 from inside the rotary target 202.

[0057] Fig. 4 is a schematic plan view showing an example of a film forming apparatus according to the present embodiment. Fig. 4 is a schematic plan view of the film forming apparatus 1 as viewed from above. At least two rotary targets are disposed in the film forming apparatus 1.

[0058] The film forming apparatus 1 includes a vacuum vessel 401, a plurality of rotary targets 201 to 210, a power source 403, a substrate holder 404, a pressure gauge 405, a gas supply system 406, a gas flow meter 407, an exhaust system 408, a control device 410, and an adhesion prevention plate 411. The substrate holder 404 supports a substrate 10.

[0059] The vacuum vessel 401 maintains a reduced pressure atmosphere by an exhaust system 408. The vacuum vessel 401 accommodates a plurality of rotary targets 201-210, a substrate holder 404, a substrate 10, etc. A pressure gauge 405 for measuring the pressure inside the vacuum vessel 401 is attached to the vacuum vessel 401. A gas supply system 406 for supplying a discharge gas (e.g., Ar, oxygen) is also attached to the vacuum vessel 401. The flow rate of the gas supplied into the vacuum vessel 401 is adjusted by a gas flow meter 407.

[0060] The multiple rotary targets 201-210 are film formation sources of the film formation apparatus 1. For example, when the multiple rotary targets 201-210 are sputtered by plasma formed in the vacuum chamber 401, sputtered particles are emitted from the multiple rotary targets 201-210 toward the substrate 10.

[0061] The power supply 403 supplies discharge power to each of the multiple rotary targets 201-210. The power supply 403 may be a DC power supply or a high-frequency power supply such as RF or VHF. When the discharge power is supplied from the power supply 403 to the multiple rotary targets 201-210, plasma is generated in the vicinity of the target surfaces 21 of the multiple rotary targets 201-210.

[0062] The control device 410 controls the discharge power input to each of the multiple rotary targets 201-210 and the rotation of the magnets. The control device 410 controls the rotational movement of the magnets 301-310 and the power supply to each of the multiple rotary targets 201-210. Furthermore, the control device 410 controls the aperture of the gas flow meter 407, etc. The pressure measured by the pressure meter 405 is sent to the control device 410. As a result, the magnets of each of the multiple rotary targets 201-210 rotate around the central axis 20, and a film is formed on the substrate 10 by sputtering.

[0063] Hereinafter, the film forming method of this embodiment controlled by the control device 410 will be described using the rotary target 202 as an example. Note that the following operation is not limited to the rotary target 202, but is also applied to each of the multiple rotary targets 201 to 210 including the rotary target 202.

[0064] 5(a) to 7(c) are schematic cross-sectional views showing the film forming method of the present embodiment.

[0065] At the moment when the discharge gas is ignited (ionized), the plasma density generally tends to be higher than when the plasma is in a steady state. Therefore, when discharge is initiated near the target surface 21 with the magnet 302 facing the substrate 10, the underlayer (organic material layer) provided on the substrate 10 is exposed to high-density plasma 22. As a result, the underlayer (organic material layer) may be damaged by any of sputtering particles, ions, radicals, and electrons (hereinafter collectively referred to as sputtering particles, etc.) contained in the plasma 22.

[0066] Therefore, in this embodiment, the magnet 302 is positioned from inside the rotary target 202 so as to face the anti-substrate side 212 of the rotary target 202 so that the plasma at the start of the discharge is not exposed to the substrate 10, and discharge power is applied to the rotary target 202 to start the discharge. This state is shown in Fig. 5(a). The rotation angle θ of the magnet 302 at the start of the discharge is set in the range of 100 degrees or more and 260 degrees or less. Fig. 5(a) shows an example of the rotation angle θ of 180 degrees as an example.

[0067] According to such an arrangement of magnets 302, at the start of discharge, plasma 22 formed near target surface 21 is formed between rotary target 202 and protection plate 411. As a result, sputtering particles and the like contained in plasma 22 are directed toward protection plate 411, not toward substrate 10, at the start of discharge. Therefore, the underlayer provided on substrate 10 is less likely to be damaged by sputtering particles and the like. Furthermore, by providing protection plate 411 on opposite side 212 to substrate 10, sputtering particles that fly from rotary target 202 at the start of discharge and do not contribute to film formation are reliably captured by protection plate 411.

[0068] Next, as shown in Fig. 5(b) and then Fig. 5(c), the magnet 302 of the rotary target 202 is rotated clockwise around the central axis 20. While the magnet 302 is rotating, the input of discharge power to the rotary target 202 is maintained. As a result, the plasma 22 moves clockwise along the target surface 21 together with the magnet 320.

[0069] 6(a), the magnet 302 is moved from inside the rotary target 202 so as to face the substrate side 211 of the rotary target 202. In this state, sputtering deposition is performed on the underlayer provided on the substrate 10.

[0070] The sputtering film formation in this embodiment is performed with the magnet 302 avoiding the reference position A. For example, the rotation angle θ of the magnet 302 from the reference position A is set in the range of 30 degrees to 90 degrees, and sputtering film formation is performed on the substrate 10. At this time, the magnet 302 is fixed at a rotation angle θ in the range of 30 degrees to 90 degrees. FIG. 6(a) shows, as an example, an example in which sputtering film formation is performed with the rotation angle θ of 30 degrees.

[0071] Next, as shown in the order of Figures 6(b), 6(c), 7(a), and 7(b), the magnet 302 of the rotary target 202 is rotated counterclockwise around the central axis 20 while supplying discharge power to the rotary target 202. This causes the plasma 22 to move counterclockwise along the target surface 21 together with the magnet 320.

[0072] 7(c), the magnet 302 is moved from inside the rotary target 202 to face the substrate side 211 of the rotary target 202, and a film is formed by sputtering on the underlayer provided on the substrate 10. Even in this case, the film is formed by sputtering on the substrate 10 with the magnet 302 avoiding the reference position A.

[0073] For example, the rotation angle θ of the magnet 302 from the reference position A is set in the range of −30 degrees to −90 degrees (270 degrees to 330 degrees), and sputtering film formation is performed on the substrate 10. At this time, the magnet 302 is fixed at a rotation angle θ in the range of −30 degrees to −90 degrees. Fig. 7(c) shows, as an example, an example in which sputtering film formation is performed with the rotation angle θ at −30 degrees.

[0074] Here, the sputtering deposition may be ended, or the magnet 302 may be rotated clockwise again thereafter, and the operations shown in Fig. 5(a) to Fig. 7(c) may be repeated. That is, sputtering deposition is performed on the substrate 10 at least once when the rotation angle θ is in the range of 30 degrees to 90 degrees, and at least once when the rotation angle θ is in the range of -30 degrees to -90 degrees. Alternatively, sputtering deposition may be performed only once when the rotation angle θ is in the range of 30 degrees to 90 degrees, or only once when the rotation angle θ is in the range of -30 degrees to -90 degrees.

[0075] Fig. 8(a) shows the state when sputtering deposition is performed on a substrate once when the magnet rotation angle θ is in the range of 30 degrees to 90 degrees and once when it is in the range of -30 degrees to -90 degrees, using adjacent rotary targets. Fig. 8(b) shows the film thickness distribution of the cathode layer formed on a substrate when sputtering deposition is performed on a substrate once when the magnet rotation angle θ is in the range of 30 degrees to 90 degrees and once when it is in the range of -30 degrees to -90 degrees.

[0076] 8(a) illustrates adjacent rotary targets 202 and 203 among the multiple rotary targets 201 to 210. The magnets 302 and 303 depicted by solid lines are in a state where sputtering film formation is performed with the rotation angle θ positioned in a range of 30 degrees to 90 degrees (e.g., 30 degrees) (first film formation), and the magnets 302 and 303 depicted by dashed lines are in a state where sputtering film formation is performed with the rotation angle θ positioned in a range of -30 degrees to -90 degrees (e.g., -30 degrees) (next film formation). Two film formation operations are shown overlapping each other in FIG. 8(a).

[0077] In this manner, when sputtering deposition is performed on the substrate 10, the magnets of adjacent rotary targets among the plurality of rotary targets 201 to 210 are rotated in the same direction.

[0078] Next, the solid line in Fig. 8(b) conceptually shows the film thickness distribution in the length direction L when sputtering film formation is performed with the rotation angle θ in the range of 30 degrees to 90 degrees (first film formation). Also, the dashed line in Fig. 8(b) conceptually shows the film thickness distribution in the length direction L when sputtering film formation is performed with the rotation angle θ in the range of -30 degrees to -90 degrees (next film formation).

[0079] It can be seen that in both the solid line and the dashed line, the film thickness is relatively high in the region of high concentration of plasma 22. However, it can be seen that the film thickness distribution becomes uniform by adding up these film thickness distributions.

[0080] In this way, by performing sputtering deposition with the rotation angle θ in the range of 30 degrees to 90 degrees or in the range of -30 degrees to -90 degrees, the perpendicular component of the sputtering particles, etc. to the underlayer is reduced, and the penetration depth of the sputtering particles, etc. into the underlayer becomes longer in appearance. As a result, the underlayer provided on the substrate 10 is not damaged by the plasma 22, and a good quality sputtering film (cathode layer 541) is formed on the underlayer. When the absolute value of the rotation angle θ is less than 30 degrees (-30°<θ<30°), the supply of discharge power to the rotary target 202 is cut off.

[0081] In addition, by performing sputtering deposition with the rotation angle θ in the range of 30 degrees to 90 degrees and sputtering deposition with the rotation angle θ in the range of -30 degrees to -90 degrees, the film thickness distribution of the sputtered film on the substrate 10 is improved.

[0082] For example, when six rotary targets are used, each rotation angle θ is assumed to be 0 degrees, and sputtering film formation is performed twice, resulting in a film thickness distribution within the substrate surface of 10.6%. When each rotation angle θ is set to 60 degrees or -60 degrees, and sputtering film formation is performed once at a rotation angle θ of 60 degrees, followed by sputtering film formation once at a rotation angle θ of -60 degrees, the film thickness distribution within the substrate surface improves to 3.9%. Furthermore, when each rotation angle θ is set to 30 degrees or -30 degrees, and sputtering film formation is performed once at a rotation angle θ of 30 degrees, followed by sputtering film formation once at a rotation angle θ of -30 degrees, the film thickness distribution within the substrate surface improves to 2.1%. Here, the film thickness distribution is calculated from the formula ((maximum film thickness)-(minimum film thickness)) / ((maximum film thickness)+(minimum film thickness))×100(%).

[0083] The discharge power when the magnet 302 faces the anti-substrate side 212 from inside the rotary target 202 may be set to be smaller than the discharge power when sputtering deposition is performed on the substrate 10. By controlling in this way, deposition between adjacent rotary targets, which may occur when the magnet 302 is located on the anti-substrate side 212, is suppressed.

[0084] (Variation 1)

[0085] 9 and 10 are schematic cross-sectional views showing Modification 1 of the film forming method of the present embodiment. In Fig. 9 and Fig. 10, rotary targets 201 and 210 arranged on both sides of a plurality of rotary targets 201 to 210 and rotary targets 202 and 209 arranged inside the rotary targets 201 and 210 are illustrated.

[0086] When sputtering film formation is performed on the substrate 10, the rotation directions of the magnets of adjacent rotary targets 201-210 may be opposite to each other. For example, as shown in Fig. 9, when the rotation angle θ of the magnet 301 of the rotary target 201 is set to 30 degrees, the rotation angle θ of the magnet 302 of the rotary target 202 adjacent to the rotary target 201 is set to -30 degrees. Also, when the rotation angle θ of the magnet 309 of the rotary target 209 is set to -30 degrees, the rotation angle θ of the magnet 310 of the rotary target 210 adjacent to the rotary target 209 is set to 30 degrees.

[0087] Further, magnets 311 and 312 are arranged on both sides of the group of rotary targets 201 to 210. A rotation mechanism (not shown) is also provided for the magnets 311 and 312, and the rotation angle θ is adjusted in the same manner as for the magnets 301 to 310. For example, in the state of FIG. 9, the magnet 311 is inclined at the same rotation angle as the magnet 309, and the magnet 312 is inclined at the same rotation angle as the magnet 302. In addition, in the state of FIG. 10, the magnet 311 is inclined at the same rotation angle as the magnet 302, and the magnet 312 is inclined at the same rotation angle as the magnet 309. Note that when the rotation angle θ of each of the magnets 301 to 312 is 0 degrees, the distance between each of the magnets 301 to 312 and the substrate 10 is the same, and each of the magnets 301 to 312 is arranged at equal intervals.

[0088] Even with such an arrangement of magnets, sputtering deposition is performed with the magnet rotation angle θ in the range of 30 degrees to 90 degrees or in the range of -30 degrees to -90 degrees, so that the base layer provided on the substrate 10 is not damaged by the plasma 22, and a high-quality sputtering film is formed on the base layer.

[0089] Furthermore, by performing sputtering deposition in the state shown in FIG. 9 at least once and sputtering deposition in the state shown in FIG. 10 at least once, the film thickness distributions in both sputtering depositions are superimposed, resulting in a good film thickness distribution of the sputtered film on the substrate 10.

[0090] Here, even if the rotation angle θ of magnet 301 becomes −30 degrees as in the state of FIG. 10, magnet 301 is adjacent to magnet 311, whose rotation angle θ is set to 30 degrees. Therefore, the magnetic field lines formed by magnet 301 and magnet 311 are substantially the same as the magnetic field lines formed by magnet 301 and magnet 302 shown in FIG. 9. Similarly, even if the rotation angle θ of magnet 310 becomes 30 degrees, magnet 312, whose rotation angle θ is set to −30 degrees, is adjacent to magnet 310. Therefore, the magnetic field lines formed by magnet 310 and magnet 312 are substantially the same as the magnetic field lines formed by magnet 309 and magnet 310 shown in FIG. 9.

[0091] As a result, even when the state shown in Figure 9 and the state shown in Figure 10 are alternately switched between, the magnets 310-310 can form pairs of adjacent magnets in which one has a rotation angle θ of 30 degrees and the other has a rotation angle θ of -30 degrees, and stable plasma discharge continues in both the states shown in Figures 9 and 10.

[0092] (Variation 2)

[0093] When sputtering film formation on the substrate 10, the rotation angle θ of the magnets 301-310 may be swung. For example, the rotation angle θ of each of the magnets 301-310 may be swung in the range of 30 degrees to 90 degrees to perform sputtering film formation at least once, and the rotation angle θ may be swung in the range of -30 degrees to -90 degrees to perform sputtering film formation at least once. By controlling the swing of the magnets in this way, the film thickness distribution of the sputtered film on the substrate 10 becomes more favorable.

[0094] (Variation 3)

[0095] Among the rotary targets 201-210, the polarity of magnets arranged inside adjacent rotary targets may be different, including magnets arranged at both ends of the group of rotary targets 201-210. For example, in FIG. 9 and FIG. 10, taking the magnet 311 and the rotary targets 201 and 202 as an example, the polarity of the magnet 301 facing the surface of the rotary target 201 is configured with an S pole in the center and an N pole surrounding the S pole, and the magnets 311 and 302 are configured with an N pole in the center and an S pole surrounding the N pole. By adopting such a configuration, the magnetic field formed between the adjacent rotary targets efficiently converges electrons and charged particles. As a result, it is possible to suppress damage to the underlayer.

[0096] (evaluation)

[0097] Two types of light-emitting device samples, samples A and B, were prepared. In samples A and B, a glass substrate was used as the substrate 10, and a 50 nm film of tris(8-quinolinolato)aluminum (commonly known as Alq3), which is a light-emitting material, was formed on the glass substrate. Furthermore, a 100 nm film of IZO (Indium-Zinc-Oxide) contained in the cathode layer 541 was formed on the Alq3 film by sputtering. Light of 390 nm was used as the excitation light. As the emission intensity of samples A and B, emission light of 533 nm, which is the peak wavelength of the emission spectrum, was detected.

[0098] Figure 11(a) is a graph showing the emission intensity (au: arbitrary unit) versus the rotation angle θ of the magnet. As shown in Figure 11(a), it can be seen that the emission intensity drops sharply when the rotation angle θ is less than 30 degrees. It is presumed that when the rotation angle θ is less than 30 degrees, the Alq3 film is damaged by sputtering particles, etc., and its functionality is reduced. On the other hand, it can be seen that when the rotation angle θ is between 30 degrees and 90 degrees, the emission intensity is higher than when the rotation angle θ is less than 30 degrees.

[0099] FIG. 11(b) is a graph showing the deposition rate (nm / min) versus the rotation angle θ of the magnet. As shown in FIG. 11(b), it can be seen that the deposition rate decreases with an increase in the rotation angle θ. And, when the rotation angle θ is 100 degrees or more, it can be seen that the deposition rate becomes approximately 0 (nm / min). From this, it was found that, although the deposition rate decreases with an increase in the rotation angle θ when the rotation angle θ is 30 degrees or more and 90 degrees or less, the cathode layer 541 can be formed on the substrate 10 when the rotation angle θ is 30 degrees or more and 90 degrees or less. In other words, when the rotation angle θ is 100 degrees or more and 260 degrees or less, the sputtering particles do not move toward the substrate 10, so the range of the rotation angle θ of 100 degrees or more and 260 degrees or less can be applied to the rotation angle for starting discharge.

[0100] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made. Each embodiment is not limited to an independent form, and can be combined as far as technically possible. [Explanation of symbols]

[0101] 1...Film deposition equipment 5...Organic light-emitting element 10...Substrate 11…Film forming surface 12a, 12b...ends 20…Central axis 21…Target surface 22...Plasma 201~210…Rotary target 211…Board side 212…opposite side of board 301~310…Magnet 401...Vacuum container 403…Power supply 404...Substrate holder 405…Pressure gauge 406…Gas supply system 407...Gas flow meter 408…Exhaust system 410...Control device 411…Adhesion prevention plate 510...Emitting layer 521...electron transport layer 522...Hole transport layer 531...Electron injection layer 532...Hole injection layer 541…Cathode layer 542...Anode layer

Claims

1. A film formation method for sputtering a substrate using a plurality of rotary targets each having a central axis and a target surface and including a magnet therein that can rotate around the central axis, comprising: The rotary targets are arranged such that the central axes are parallel to each other and the central axes are parallel to the substrate; In each of the plurality of rotary targets, when a side where a line extending radially from the central axis intersects with the substrate is defined as a substrate side of the target surface, and a side opposite to the substrate side is defined as an anti-substrate side of the target surface, The magnet is positioned so as to face the opposite side of the substrate from the inside, and discharge power is applied to the rotary targets; While supplying the discharge power to the rotary targets, the magnets of the rotary targets are rotated about the central axis to move the magnets from the inside to face the substrate side; performing sputtering deposition on the substrate while avoiding a reference position where the magnet is closest to the substrate; If the rotation angle of the magnet when the magnet is located at the reference position is defined as 0 degrees, and rotating the magnet in the counterclockwise direction is defined as a positive rotation angle, the rotation angle of the magnet from the reference position is set in a range of 30 degrees to 90 degrees or in a range of −30 degrees to −90 degrees, and sputtering is performed on the substrate; When the absolute value of the rotation angle is less than 30 degrees, the supply of the discharge power to the plurality of rotary targets is cut off. Film formation method.

2. 2. The film forming method according to claim 1, When the magnet is opposed to the opposite side of the substrate from the inside and discharge power is applied to the rotary targets, the rotation angle is set in the range of 100 degrees to 260 degrees. Film formation method.

3. The film forming method according to claim 1 or 2, The discharge power when the magnet is caused to face the opposite side of the substrate from the inside is set to be smaller than the discharge power when forming a film on the substrate by sputtering. Film formation method.

4. The film forming method according to any one of claims 1 to 3, When sputtering is performed on the substrate, the magnets of adjacent rotary targets among the plurality of rotary targets are rotated in the same direction. Film formation method.

5. The film forming method according to any one of claims 1 to 3, When sputtering is performed on the substrate, the magnets of adjacent rotary targets among the plurality of rotary targets are rotated in opposite directions. Film formation method.

6. The film forming method according to any one of claims 1 to 5, Sputtering deposition is performed on the substrate at least once when the rotation angle is in the range of 30 degrees to 90 degrees and at least once when the rotation angle is in the range of -30 degrees to -90 degrees. Film formation method.

7. The film forming method according to any one of claims 1 to 6, The magnet is oscillated at least once in a range of the rotation angle from 30 degrees to 90 degrees, and at least once in a range of from −30 degrees to −90 degrees, and sputtering film formation is performed on the substrate. Film formation method.

8. A substrate holder for supporting a substrate; a plurality of rotary targets each having a central axis and a target surface, each including a magnet rotatable about the central axis, the plurality of rotary targets being arranged such that the central axes are parallel to each other and parallel to the substrate; a power source that supplies discharge power to each of the plurality of rotary targets; a control device that controls the discharge power input to each of the plurality of rotary targets and the rotation of the magnet; Equipped with The control device includes: In each of the plurality of rotary targets, when a side where a line extending radially from the central axis intersects with the substrate is defined as a substrate side of the target surface, and a side opposite to the substrate side is defined as an anti-substrate side of the target surface, The magnet is positioned so as to face the opposite side of the substrate from the inside, and discharge power is applied to the rotary targets; While supplying the discharge power to the rotary targets, the magnets of the rotary targets are rotated about the central axis to move the magnets from the inside to face the substrate side; performing control to perform sputtering deposition on the substrate while avoiding a reference position where the magnet is closest to the substrate; If the rotation angle of the magnet when the magnet is located at the reference position is defined as 0 degrees, and rotating the magnet in the counterclockwise direction is defined as a positive rotation angle, the rotation angle of the magnet from the reference position is set in a range of 30 degrees to 90 degrees or in a range of −30 degrees to −90 degrees, and sputtering is performed on the substrate; When the absolute value of the rotation angle is less than 30 degrees, the supply of the discharge power to the plurality of rotary targets is cut off. Film deposition equipment.

9. 9. The film forming apparatus according to claim 8, When the magnet is opposed to the opposite side of the substrate from the inside and discharge power is applied to the rotary targets, the rotation angle is set in the range of 100 degrees to 260 degrees. Film deposition equipment.

10. 10. The film forming apparatus according to claim 8, The discharge power when the magnet is caused to face the opposite side of the substrate from the inside is set to be smaller than the discharge power when forming a film on the substrate by sputtering. Film deposition equipment.

11. The film forming apparatus according to any one of claims 8 to 10, When sputtering is performed on the substrate, the magnets of adjacent rotary targets among the plurality of rotary targets are rotated in the same direction. Film deposition equipment.

12. In the film forming apparatus according to any one of claims 8 to 10, When sputtering is performed on the substrate, the magnets of adjacent rotary targets among the plurality of rotary targets are rotated in opposite directions. Film deposition equipment.

13. The film forming apparatus according to any one of claims 8 to 12, Sputtering deposition is performed on the substrate at least once when the rotation angle is in the range of 30 degrees to 90 degrees and at least once when the rotation angle is in the range of -30 degrees to -90 degrees. Film deposition equipment.

14. The film forming apparatus according to any one of claims 8 to 13, The magnet is oscillated at least once in a range of the rotation angle from 30 degrees to 90 degrees, and at least once in a range of from −30 degrees to −90 degrees, and sputtering film formation is performed on the substrate. Film deposition equipment.

Images