JP2023033718A - Film deposition method and film deposition apparatus - Google Patents

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

The present invention relates to a film forming method and a film forming apparatus.

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

JP 2007-317384 A JP-A-2002-343555

However, when the electrode layer is formed on the underlying layer by the sputtering method, the underlying layer may be damaged. In particular, the underlying layer is composed of an organic material, and if damage enters the underlying layer, the characteristics of the electronic device may deteriorate.

In view of the circumstances as described above, an object of the present invention is to provide a film forming method and a film forming apparatus that suppresses damage to an underlying layer when an electrode layer is formed on the underlying layer by a sputtering method. .

In order to achieve the above object, a film formation method according to one aspect of the present invention uses a plurality of rotary targets each having a central axis and a target surface and having a magnet inside that is rotatable about the central axis. This is a film forming method for forming a film by sputtering on a substrate.
In the film forming method, the plurality of 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, the side where the line radially extending from the central axis intersects the substrate is defined as the substrate side of the target surface, and the side opposite to the substrate side is defined as the counter-substrate side of the target surface. case,
Discharge power is applied to the plurality of rotary targets by positioning the magnet so as to face the opposite side of the substrate from the inside,
rotating the magnets of the plurality of rotary targets about the central axis while supplying the discharge power to the plurality of rotary targets so that the magnets move from the inside to face the substrate;
Sputtering film formation is performed on the substrate while avoiding the reference position where the magnet is closest to the substrate.

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

In the above-described film formation method, when the rotation angle of the magnet when the magnet is positioned at the reference position is 0 degrees, and the rotation of the magnet in the counterclockwise direction is defined as the 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 the sputtering deposition may be performed on the substrate.

In the above film forming method, 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 may be cut off.

In the above film forming method, when the magnet is opposed to the opposite side of the substrate from the inside and the discharge power is supplied to the plurality of rotary targets, the rotation angle is within the range of 100 degrees to 260 degrees. may be set.

In the above-described film formation method, the discharge power when the magnet is opposed to the opposite side of the substrate from the inside may be set smaller than the discharge power when the sputtering film is formed on the substrate.

In the above-described film formation method, when sputtering film formation is performed on the substrate, the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets may be oriented in the same direction.

In the above-described film formation method, when sputtering film formation is performed on the substrate, the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets may be directed in opposite directions.

In the above film forming method, sputtering film formation is performed on the substrate at least once in the range of the rotation angle of 30 degrees to 90 degrees and at least once in the range of -30 degrees to -90 degrees. good too.

In the film forming method, the magnet is oscillated at least once in the range of the rotation angle of 30 degrees to 90 degrees, and the magnet is oscillated in the range of -30 degrees to -90 degrees. The substrate may be sputter deposited at least once.

In order to achieve the above object, a film forming apparatus according to one aspect of the present invention includes:
a substrate holder that supports the substrate;
a plurality of rotary targets as described above;
a power supply that supplies discharge power to each of the plurality of rotary targets;
A controller for controlling the rotation of the magnet and discharge power to be applied to each of the plurality of rotary targets is provided.
The control device is
In each of the plurality of rotary targets, the side where the line radially extending from the central axis intersects the substrate is defined as the substrate side of the target surface, and the side opposite to the substrate side is defined as the counter-substrate side of the target surface. case,
Discharge power is applied to the plurality of rotary targets by positioning the magnet so as to face the opposite side of the substrate from the inside,
rotating the magnets of the plurality of rotary targets about the central axis while supplying the discharge power to the plurality of rotary targets so that the magnets face the substrate side from the inside;
Control is performed to deposit a sputtering film on the substrate while avoiding the reference position where the magnet is closest to the substrate.

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

In the film forming apparatus, when the rotation angle of the magnet when the magnet is positioned at the reference position is 0 degrees, and the rotation of the magnet in the counterclockwise direction is the 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 may be performed on the substrate.

In the film forming apparatus, when the absolute value of the rotation angle is less than 30 degrees, application of the discharge power to the plurality of rotary targets may be cut off.

In the film forming apparatus, the magnet is opposed to the side opposite to the substrate from the inside, and the rotation angle is set in the range of 100 degrees to 260 degrees when discharging power is supplied to the plurality of rotary targets. may be

In the film forming apparatus, the discharge power when the magnet faces the opposite side of the substrate from the inside may be set to be smaller than the discharge power when sputtering the film on the substrate.

In the film forming apparatus, when sputtering film formation is performed on the substrate, the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets may be oriented in the same direction.

In the film forming apparatus, when sputtering film formation is performed on the substrate, the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets may be directed in opposite directions.

In the film deposition apparatus, sputtering film formation is performed on the substrate at least once in the range of the rotation angle of 30 degrees to 90 degrees and at least once in the range of -30 degrees to -90 degrees. good.

In the film forming apparatus, the magnet is oscillated at least once in the rotation angle range of 30 degrees to 90 degrees, and the magnet is oscillated in the rotation angle range of −30 degrees to −90 degrees at least once. The substrate may be sputter deposited once.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, there is provided a film forming method and a film forming apparatus capable of suppressing damage to an underlying layer when an electrode layer is formed on the underlying layer by a sputtering method.

1 is a schematic cross-sectional view showing an organic light-emitting device of this embodiment; FIG. 1 is a schematic cross-sectional view showing an example of a film forming apparatus according to an embodiment; FIG. FIG. 4 is a diagram for explaining the definition of the angle of a magnet that rotates around the central axis of a rotary target; 1 is a schematic plan view showing an example of a film forming apparatus of this embodiment; FIG. It is a typical sectional view showing the film-forming method of this embodiment. It is a typical sectional view showing the film-forming method of this embodiment. It is a typical sectional view showing the film-forming method of this embodiment. FIG. (a) shows that, in adjacent rotary targets, sputtering film formation occurs on the substrate once when the rotation angle θ of the magnet is in the range of 30 degrees to 90 degrees and once in the range of −30 degrees to −90 degrees. It is a typical cross section showing a state when it is performed. FIG. (b) shows the substrate after sputtering film formation was performed once in the range of the rotation angle θ of the magnet from 30 degrees to 90 degrees and once in the range of −30 degrees to −90 degrees. 2 is a conceptual graph showing the film thickness distribution of a cathode layer formed on the . It is a schematic cross-sectional view showing Modification 1 of the film forming method of the present embodiment. It is a schematic cross-sectional view showing Modification 1 of the film forming method of the present embodiment. FIG. (a) is a graph showing the emission intensity with respect to the rotation angle θ of the magnet. FIG. (b) is a graph showing the film formation rate (nm/min) with respect to the rotation angle θ of the magnet.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. XYZ axis coordinates may be introduced in each drawing. Also, the same reference numerals may be given to the same members or members having the same function, and the description may be omitted as appropriate after the description of the members. Also, the numerical values shown below are examples, and the present invention is not limited to these examples.

FIG. 1 is a schematic cross-sectional view showing the organic light-emitting device of this embodiment. FIG. 1 shows a main part of a top-emission type organic light emitting device 5 as an example.

The organic light emitting device 5 includes a light emitting layer (EML) 510, an electron transport layer (ETL) 521, a hole transport layer (HTL) 522, an electron injection layer (EIL) 531, and a hole injection layer (HIL) 532. , a cathode layer 541 and an anode layer 542 . In the organic light emitting device 5, the hole injection layer 532, the hole transport layer 522, the light emitting 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. .

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 . A 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 .

In the organic light-emitting device 5 , light emitted from the light-emitting layer 510 is extracted from the cathode layer 541 . On the opposite side of the cathode layer 541, that is, under the anode layer 542, a support substrate (not shown) that supports the organic light emitting device 5 is arranged. Thin film transistors, circuits such as wiring, interlayer insulating layers, and the like are arranged on the substrate (none of which is shown). The support substrate may be a flexible substrate or an inflexible plate-like substrate.

The cathode layer 541 is composed of a conductive layer with excellent light transmittance and low resistance. The cathode layer 541 is a sputtering layer (also referred to as a sputtering film) formed under a reduced pressure atmosphere, and has a thickness greater than 10 nm and less than or equal to 20 nm, preferably greater than or equal to 15 nm and less than or equal to 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.

Further, when the cathode layer 541 is composed only of the metal layer described above, the thickness thereof is 20 nm or less, which limits the resistance and mechanical strength of the cathode layer 541 . To compensate for this, a transparent conductive layer made of a transparent conductive oxide may be deposited on the metal layer by sputtering. If it is a transparent conductive oxide, it is excellent in translucency and also in electrical conductivity. 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 in which the metal layer/the transparent conductive oxide layer are arranged in this order from the base.

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 lanthanide. For example, the electron injection layer 531 contains 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 increase light transmission, and is, for example, 5 nm or more and 10 nm or less.

When a voltage is applied between the anode layer 542 and the cathode layer 541 , holes are injected from the hole injection layer 532 into the hole transport layer 522 and electrons are injected from the electron injection layer 531 into the electron transport layer 521 . Subsequently, the holes that have moved through the hole-transporting layer 522 and the electrons that have moved through the electron-transporting layer 521 recombine in the light-emitting layer 510 to generate light in the light-emitting layer 510 . Light generated in the light-emitting layer 510 is emitted from the light-emitting layer 510 to each side of the anode layer 542 and the cathode layer 541 .

The organic light emitting device 5 is of 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 have a light transmittance of emitted light. is highly configured. Also, the anode layer 542 is configured to reflect emitted light. As a result, the light emitted from the light-emitting layer 510 directly directed to the cathode layer 541 and the light reflected by the anode layer 542 are synthesized, and the light emitted from the organic light-emitting device 5 passes through the cathode layer 541, and the organic light-emitting device 5 is released to the outside.

Here, when the cathode layer 541 is formed on the electron injection layer 531, 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 below the cathode layer 541 It is preferable that the organic material layer is not damaged. If these organic material layers are damaged, the emission characteristics of the organic light-emitting element 5 may deteriorate, or the electrical characteristics may deteriorate.

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 in which the organic material layer below the cathode layer 541 is less likely to be damaged. Furthermore, a film forming method and a film forming apparatus exhibiting excellent characteristics in film thickness distribution of the cathode layer 541 are provided.

2A and 2B are schematic cross-sectional views showing an example of the film forming apparatus of this embodiment. FIG. 2(a) shows a schematic cross section showing the positional relationship between the plurality of rotary targets and the substrate in the film forming apparatus 1, and FIG. 2(b) shows a schematic plan view showing the positional relationship. It is shown.

A magnetron sputtering apparatus is exemplified as the film forming apparatus 1 of the present embodiment. In the film forming apparatus 1 , at least two 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 to 210 are illustrated in FIGS. 2(a) and 2(b). The number of multiple rotary targets is not limited to this number, and can be changed as appropriate according to the size of the substrate 10, for example. Assume that the substrate 10 is provided with a base layer (organic material layer) under the cathode layer 541 .

Each of the multiple rotary targets 201 to 210 has a central axis 20 and a target surface (sputtering surface) 21 . Each of the plurality of rotary targets 201 to 210 has a magnet inside that can rotate around the central axis 20 . For example, in the examples of FIGS. 2A and 2B, magnets 301-310 are arranged in order of a plurality of rotary targets 201-210. Magnets 301-310 are a so-called magnet assembly. Magnets 301-310 have permanent magnets and magnetic yokes. The film forming apparatus 1 is provided with a rotating mechanism (not shown) for rotating the rotary targets 201 to 210 and the magnets 301 to 310 .

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

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

2A and 2B, the direction in which the plurality of rotary targets 201 to 210 are arranged corresponds to the Y-axis direction, and the direction from the substrate 10 toward the plurality of rotary targets 201 to 210 corresponds to the Z-axis. , and the direction in which each of the plurality of rotary targets 201 to 210 extends corresponds to the X axis.

When the plurality of rotary targets 201 to 210 and the substrate 10 are viewed in the Z-axis direction, the pair of rotary targets 201 and 210 arranged at both ends are arranged so as to protrude from the substrate 10 in the Y-axis direction. For example, the plurality of rotary targets 201 to 210 and the substrate 10 are arranged such that at least part of each of the pair of rotary targets 201 and 210 and the substrate 10 overlap.

In the examples of FIGS. 2A and 2B, the central axis 20 of the rotary target 201 and the end portion 12a of the substrate 10 in the Y-axis direction overlap in the Z-axis direction. Also, the central axis 20 of the rotary target 210 and the end portion 12b of the substrate 10 in the Y-axis direction overlap.

The pitches of the plurality of rotary targets 201 to 210 are set substantially equal in the Y-axis direction. Also, the relative distances between the plurality of rotary targets 201 to 210 and the substrate 10 during sputtering film formation are fixed.

The material of the multiple rotary targets 201 to 210 is, for example, the material forming the cathode layer 541 . The substrate 10 is, for example, an organic resin sheet including an organic material layer under the cathode layer 541, or a glass plate including the organic material layer.

In the present embodiment, discharge power is applied to each of the plurality of rotary targets 201 to 210, and the magnets of each of the plurality of rotary targets 201 to 210 rotate around the central axis 20, thereby sputtering film formation on the substrate 10. done.

The same electric power is applied to each of the plurality of rotary targets 201 to 210 in order to make the consumption of each rotary target substantially uniform. The applied power may be DC power or AC power in the RF band, VHF band, or the like. Also, each of the plurality of rotary targets 201-210 can rotate clockwise or counterclockwise. Each of the multiple rotary targets 201 to 210 rotates clockwise or counterclockwise during film formation.

FIG. 3 is a diagram for explaining the definition of the angle of the magnet rotating around the central axis of the rotary target. In FIG. 3, as an example, the rotary target 202 is illustrated among the plurality of rotary targets 201-210. Regarding the definitions of the magnet angle, the positive angle, the negative angle, and the reference position A (described later), the rotary targets 201, 203 to 210 other than the rotary target 202, that is, the plurality of rotary targets 201, 203 to 210 are also defined. , are defined similarly to the rotary target 202 . In addition, an anti-adhesion plate 411 not shown in FIG. 2A is arranged on the opposite side of the substrate 10 with the rotary target 202 interposed therebetween.

Regarding the rotation angle θ of the magnet 302, the angle of the magnet 302 when the distance between the center of the magnet 302 and the substrate 10 is the shortest is 0 degree. For example, when a perpendicular line is drawn from the central axis 20 to the deposition surface 11 of the substrate 10, the position where the perpendicular line and the center 30 of the magnet 302 coincide corresponds to the angle of the magnet 302 of 0 degrees. As the magnet 302 rotates about the central axis 20, its center 30 traces an arc-shaped orbit. When the angle is 0 degree, the magnet 310 is closest to the substrate 10, and the position on the arc at this time is defined as the reference position A. FIG.

In other words, at reference position A, magnet 302 is closest to substrate 10 . When the magnet 302 is positioned at the reference position A, the rotation angle θ of the magnet 302 is 0 degrees. Regarding the positive/negative of the angle of the magnet 302, the direction when the magnet 302 is rotated counterclockwise from 0 degrees is a positive rotation angle (+θ), and the direction when the magnet 302 is rotated clockwise is negative. is the rotation angle (-θ). It is assumed that the position of the magnet 302 is the angular position of the center 30 at a certain angle.

In the present embodiment, in each of the plurality of rotary targets 201 to 210, the side where the line 25 radially extending from the central axis 20 intersects the substrate 10 is defined as the substrate side 211 of the target surface 21. The opposite side is the non-substrate side 212 of the target surface 21 .

By rotating the magnet 302 around the central axis 20 of the rotary target 202, the plasma can be concentrated near the target surface 21 facing the magnet 302 during magnetron discharge. Sputtered particles can be preferentially emitted from the target surface 21 facing the magnet 302 . 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 . In addition, in the magnet 302 , the S pole and the N pole surrounding the S pole face the rotary target 202 from the inside of the rotary target 202 .

FIG. 4 is a schematic plan view showing an example of the film forming apparatus of this embodiment. FIG. 4 schematically shows a plan view of the film forming apparatus 1 viewed from above. At least two or more rotary targets are arranged in the film forming apparatus 1 .

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, and an exhaust system 408. , a control device 410 and an anti-adhesion plate 411 . The substrate 10 is supported by the substrate holder 404 .

The vacuum vessel 401 maintains a reduced pressure atmosphere by an exhaust system 408 . A vacuum vessel 401 accommodates a plurality of rotary targets 201 to 210, a substrate holder 404, a substrate 10, and the like. 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 (for example, Ar or oxygen) is attached to the vacuum vessel 401 . A gas flow meter 407 adjusts the flow rate of the gas supplied into the vacuum container 401 .

A plurality of rotary targets 201 to 210 are film formation sources of the film formation apparatus 1 . For example, when the plurality of rotary targets 201 - 210 are sputtered by the plasma formed within the vacuum vessel 401 , sputtered particles are emitted from the plurality of rotary targets 201 - 210 toward the substrate 10 .

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

The control device 410 controls the discharge power and the rotation of the magnets applied to each of the plurality of rotary targets 201-210. A control device 410 controls the rotational movement of the magnets 301-310 and power supply to each of the plurality of rotary targets 201-210. Furthermore, the control device 410 controls the opening degree of the gas flow meter 407 and the like. The pressure measured by pressure gauge 405 is sent to control device 410 . As a result, the magnets of the plurality of rotary targets 201 to 210 rotate around the central axis 20, and sputtering film formation is performed on the substrate 10. FIG.

The film forming method of this embodiment controlled by the controller 410 will be described below using the rotary target 202 as an example. Note that the following operation is applied not only to the rotary target 202 but also to each of the plurality of rotary targets 201 to 210 including the rotary target 202. FIG.

5A to 7C are schematic cross-sectional views showing the film forming method of this embodiment.

At the moment 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 the discharge is started near the target surface 21 with the magnet 302 facing the substrate 10, the underlying layer (organic material layer) provided on the substrate 10 is exposed to the high-density plasma 22. As a result, any of sputtered particles, ions, radicals, and electrons (hereinafter collectively referred to as sputtered particles and the like) contained in the plasma 22 may damage the underlying layer (organic material layer).

Therefore, in this embodiment, the magnet 302 is positioned from inside the rotary target 202 so as to face the opposite side 212 of the rotary target 202 so that the substrate 10 is not exposed to the plasma at the start of discharge. Discharge power is supplied to start discharge. This state is shown in FIG. The rotation angle θ of the magnet 302 at the start of discharge is set within the range of 100 degrees or more and 260 degrees or less. In FIG. 5A, as an example, the rotation angle θ is 180 degrees.

According to such arrangement of the magnets 302 , the plasma 22 formed near the target surface 21 is formed between the rotary target 202 and the anti-adhesion plate 411 at the start of discharge. As a result, the sputtered particles and the like contained in the plasma 22 go toward the anti-adhesion plate 411 instead of the substrate 10 at the start of discharge. Therefore, the underlying layer provided on the substrate 10 is less likely to be damaged by sputtered particles or the like. In addition, by setting the anti-adhesion plate 411 on the opposite side 212 to the substrate, the anti-adhesion plate 411 reliably captures sputtered particles that fly from the rotary target 202 at the start of discharge and do not contribute to film formation.

Next, as shown in FIG. 5(b) and then in FIG. 5(c), the magnet 302 of the rotary target 202 is rotated clockwise around the central axis 20. Then, as shown in FIG. While the magnet 302 is rotating, the discharge power is kept applied to the rotary target 202 . This causes the plasma 22 to move clockwise along the target surface 21 together with the magnet 320 .

Next, as shown in FIG. 6A, 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 film formation is performed on the underlying layer provided on the substrate 10 .

The sputtering film formation of this embodiment is performed in a state where the magnet 302 avoids the reference position A. FIG. 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 so that the rotation angle θ is in the range of 30 degrees to 90 degrees. FIG. 6A shows, as an example, an example in which a film is formed by sputtering at a rotation angle θ of 30 degrees.

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

Next, as shown in FIG. 7C, the magnet 302 is moved from inside the rotary target 202 so as to face the substrate side 211 of the rotary target 202, and sputtering is performed on the underlying layer provided on the substrate 10. As shown in FIG. Film formation is performed. Even in this case, sputtering film formation is performed on the substrate 10 while the magnet 302 avoids the reference position A. FIG.

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 (range of 270 degrees to 330 degrees), and sputtering film formation is performed on the substrate 10 . At this time, the magnet 302 is fixed so that the rotation angle θ is in the range of -30 degrees to -90 degrees. FIG. 7(c) shows, as an example, an example in which the film is formed by sputtering at a rotation angle θ of −30 degrees.

Here, the sputtering film formation may be terminated, or after this, the magnet 302 may be rotated clockwise again and the operations shown in FIGS. 5(a) to 7(c) may be repeated. That is, sputtering film formation is performed on the substrate 10 at least once within the range of the rotation angle θ from 30 degrees to 90 degrees and at least once within the range of −30 degrees to −90 degrees. Alternatively, the sputtering film formation may be performed only once in the range of the rotation angle θ from 30 degrees to 90 degrees, or only once in the range of -30 degrees to -90 degrees.

In FIG. 8(a), in the adjacent rotary targets, the sputtering film was formed on the substrate once when the rotation angle θ of the magnet was in the range of 30 degrees to 90 degrees and once in the range of −30 degrees to −90 degrees. shows how it was done. In addition, in FIG. 8B, sputtering film formation was performed on the substrate once when the rotation angle θ of the magnet was in the range of 30 degrees to 90 degrees and once in the range of −30 degrees to −90 degrees. 4 shows the film thickness distribution of the cathode layer formed on the substrate in the case of FIG.

FIG. 8(a) illustrates adjacent rotary targets 202 and 203 among a plurality of rotary targets 201-210. The magnets 302 and 303 drawn by solid lines are in the state when sputtering film formation is performed with the rotation angle θ in the range of 30 degrees to 90 degrees (for example, 30 degrees) (first film formation). The magnets 302 and 303 drawn by dashed lines are in the state (next film formation) when the sputtering film formation is performed with the rotation angle θ in the range of −30 degrees to −90 degrees (for example, −30 degrees). is. In FIG. 8A, two film forming operations are superimposed.

As described above, when sputtering film formation is performed on the substrate 10, the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets 201 to 210 are oriented in the same direction.

Next, the solid line shown in FIG. 8B shows the film thickness distribution in the length direction L when sputtering film formation is performed with the rotation angle θ positioned in the range of 30 degrees to 90 degrees (first film formation). is conceptually shown. Further, the dashed line shown in FIG. 8B indicates the film thickness in the length direction L when sputtering film formation is performed with the rotation angle θ positioned in the range of −30 degrees to −90 degrees (next film formation). It shows the distribution conceptually.

It can be seen that both the solid line and the dashed line show that the film thickness is relatively high in the region where the plasma 22 is dense. However, it can be seen that the film thickness distribution becomes uniform by adding these film thickness distributions.

As described above, sputtering film formation is performed 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 penetration depth of sputtered particles or the like into the underlying layer becomes apparently longer. As a result, the underlying layer provided on the substrate 10 is not damaged by the plasma 22, and a high-quality sputtering film (cathode layer 541) is formed on the underlying layer. When the absolute value of the rotation angle θ is less than 30 degrees (−30°<θ<30°), the discharge power to the rotary target 202 is cut off.

Further, by performing sputtering film formation with the rotation angle θ positioned in the range of 30 degrees to 90 degrees and sputtering film formation with the rotation angle θ positioned in the range of −30 degrees to −90 degrees , the film thickness distribution of the sputtered film on the substrate 10 is improved.

For example, when the film thickness distribution in the substrate surface is 10.6% when sputtering film formation is performed twice using six rotary targets with a rotation angle θ of 0 degrees, Each rotation angle θ was set to 60 degrees or −60 degrees, and sputtering film formation was performed once at a rotation angle θ of 60 degrees, and then once at a rotation angle θ of −60 degrees. In this case, the film thickness distribution within the substrate plane is improved to 3.9%. Furthermore, each rotation angle θ was set to 30 degrees or -30 degrees, and sputtering film formation was performed once at a rotation angle θ of 30 degrees, and then sputtering film formation was performed once at a rotation angle θ of -30 degrees. The film thickness distribution within the substrate plane is improved to 2.1% when this is carried out. Here, the film thickness distribution is a formula of ((maximum film thickness) - (minimum film thickness)) / ((maximum film thickness) + (minimum film thickness)) x 100 (%) calculated from

The discharge power when the magnet 302 is opposed to the opposite side 212 of the rotary target 202 from inside the rotary target 202 may be set smaller than the discharge power when sputtering film formation is performed on the substrate 10 . Such control suppresses film deposition between adjacent rotary targets that may occur when the magnet 302 is positioned on the opposite side 212 of the substrate.

(Modification 1)

9 and 10 are schematic cross-sectional views showing Modification 1 of the film forming method of this embodiment. 9 and 10 illustrate 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 them.

When sputtering film formation is performed on the substrate 10, in the plurality of rotary targets 201 to 210, the rotation directions of magnets of adjacent rotary targets may be directed in opposite directions. 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 -30 degrees. set. 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.

Magnets 311 and 312 are arranged on both sides of the group of rotary targets 201-210. The magnets 311 and 312 are also provided with a rotation mechanism (not shown) to adjust the rotation angle θ in the same manner as the magnets 301-310. For example, in the state of FIG. 9, magnet 311 is tilted at the same rotation angle as magnet 309 and magnet 312 is tilted at the same rotation angle as magnet 302 . 10, the magnet 311 is tilted at the same angle of rotation as the magnet 302, and the magnet 312 is tilted at the same angle of rotation as the magnet 309. FIG. When the rotation angle θ of each of the magnets 301 to 312 is 0 degree, 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 regular intervals. ing.

Even with such an arrangement of magnets, sputtering film formation is performed at a rotation angle θ of the magnets in the range of 30 degrees to 90 degrees or in the range of −30 degrees to −90 degrees. A high-quality sputtering film is formed on the underlying layer without being damaged by the plasma 22 .

Furthermore, by performing sputtering film formation at least once in the state shown in FIG. 9 and at least once sputtering film formation in the state shown in FIG. As a result, the film thickness distribution of the sputtered film on the substrate 10 is improved.

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

As a result, even if the state shown in FIG. 9 and the state shown in FIG. 10 are alternately switched, the magnets 310 to 310 are adjacent to each other such that one rotation angle θ is 30 degrees and the other rotation angle θ is -30 degrees. A pair can be formed, and the plasma discharge continues stably in the states shown in both FIGS.

(Modification 2)

When sputtering film formation is performed on the substrate 10, the rotation angle θ of the magnets 301 to 310 may be oscillated. For example, the rotation angle θ of each of the magnets 301 to 310 is oscillated in the range of 30 degrees to 90 degrees to perform sputtering deposition at least once, and the rotation angle θ is oscillated in the range of −30 degrees to −90 degrees to perform sputtering. Deposition may be performed at least once. The film thickness distribution of the sputtered film on the substrate 10 is improved by controlling the oscillation of the magnet in this manner.

(Modification 3)

Among the rotary targets 201-210, the polarities of the magnets arranged inside the adjacent rotary targets may be made different, including the magnets arranged at both ends of the group of the rotary targets 201-210. For example, in FIGS. 9 and 10, taking the magnet 311 and the rotary targets 201 and 202 as an example, the polarities of the magnet 301 toward the surface of the rotary target 201 are the S pole in the center and the N pole surrounding the S pole. The magnets 311 and 302 have an N pole at the center and an S pole surrounding the N pole. By adopting such a configuration, the magnetic field formed between adjacent rotary targets efficiently converges electrons and charged particles. As a result, it is possible to suppress damage to the underlying layer.

(evaluation)

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

FIG. 11(a) is a graph showing the emission intensity (a.u.: arbitrary unit) with respect to the rotation angle θ of the magnet. As shown in FIG. 11(a), when the rotation angle .theta. If the rotation angle θ is less than 30 degrees, it is presumed that the Alq3 film will be damaged by sputtered particles or the like, and its function will deteriorate. On the other hand, when the rotation angle .theta.

FIG. 11(b) is a graph showing the film formation rate (nm/min) with respect to the rotation angle θ of the magnet. As shown in FIG. 11(b), it can be seen that the deposition rate decreases as the rotation angle θ increases. It can be seen that when the rotation angle .theta. is 100 degrees or more, the deposition rate becomes approximately 0 (nm/min). As a result, when the rotation angle θ is 30 degrees or more and 90 degrees or less, the deposition rate decreases as the rotation angle θ increases. I found out. In other words, when the rotation angle θ is 100 degrees or more and 260 degrees or less, the sputtered particles do not face the substrate 10. Therefore, the rotation angle θ of 100 degrees or more and 260 degrees or less can be applied to the rotation angle for starting discharge.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments and can be modified in various ways. Each embodiment is not limited to an independent form, and can be combined as much as technically possible.

DESCRIPTION OF SYMBOLS 1... Film-forming apparatus 5... Organic light-emitting element 10... Substrate 11... Film-forming surface 12a, 12b... Edge part 20... Central axis 21... Target surface 22... Plasma 201 to 210... Rotary target 211... Substrate side 212... Anti-substrate side DESCRIPTION OF SYMBOLS 301-310... Magnet 401... Vacuum vessel 403... Power supply 404... Substrate holder 405... Pressure gauge 406... Gas supply system 407... Gas flow meter 408... Exhaust system 410... Control device 411... Anti-adhesion plate 510... Light 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 (18)

A method of forming a film by sputtering on a substrate using a plurality of rotary targets having a central axis and a target surface and having magnets inside that are rotatable about the central axis, the method comprising:
arranging the plurality of rotary targets so 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, the side where the line radially extending from the central axis intersects the substrate is defined as the substrate side of the target surface, and the side opposite to the substrate side is defined as the anti-substrate side of the target surface. case,
Discharge power is applied to the plurality of rotary targets by positioning the magnet so as to face the opposite side of the substrate from the inside,
rotating the magnets of the plurality of rotary targets about the central axis while supplying the discharge power to the plurality of rotary targets so that the magnets face the substrate side from the inside;
A method of forming a film by sputtering on the substrate while avoiding a reference position where the magnet is closest to the substrate. In the film forming method according to claim 1,
When the rotation angle of the magnet when the magnet is positioned at the reference position is 0 degrees, and the counterclockwise rotation of the magnet is a positive rotation angle,
A film forming method, wherein the rotation angle of the magnet from the reference position is set in the range of 30 degrees to 90 degrees, or in the range of -30 degrees to -90 degrees, and sputtering film formation is performed on the substrate. In the film forming method according to claim 2,
The film forming method, wherein the application of the discharge power to the plurality of rotary targets is interrupted when the absolute value of the rotation angle is less than 30 degrees. In the film forming method according to claim 2 or 3,
The film formation method, wherein the rotation angle is set in the range of 100 degrees to 260 degrees when the magnet is opposed to the side opposite to the substrate from the inside and discharge power is applied to the plurality of rotary targets. In the film forming method according to any one of claims 1 to 4,
The method of depositing a film, wherein the discharge power when the magnet is opposed from the inside to the side opposite to the substrate is set to be smaller than the discharge power when sputtering film is formed on the substrate. In the film forming method according to any one of claims 2 to 5,
The method of forming a film, wherein when sputtering film formation is performed on the substrate, the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets are oriented in the same direction. In the film forming method according to any one of claims 2 to 5,
The film forming method, wherein when sputtering film formation is performed on the substrate, the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets are directed in opposite directions. In the film forming method according to any one of claims 2 to 7,
A film forming method, wherein sputtering film formation is performed on the substrate at least once within the range of the rotation angle of 30 degrees to 90 degrees and at least once within the range of -30 degrees to -90 degrees. In the film forming method according to any one of claims 2 to 8,
Sputtering onto the substrate at least once by oscillating the magnet within the range of the rotation angle of 30 degrees to 90 degrees and at least once by oscillating the magnet within the range of −30 degrees to −90 degrees A deposition method in which deposition is performed. a substrate holder that supports the substrate;
A plurality of rotaries having a central axis and a target surface, having therein magnets rotatable around the central axis, and arranged such that the central axes are parallel to each other and the central axes are parallel to the substrate. target and
a power supply that supplies discharge power to each of the plurality of rotary targets;
a control device for controlling discharge power and rotation of the magnets to be applied to each of the plurality of rotary targets,
The control device is
In each of the plurality of rotary targets, the side where the line radially extending from the central axis intersects the substrate is defined as the substrate side of the target surface, and the side opposite to the substrate side is defined as the anti-substrate side of the target surface. case,
Discharge power is applied to the plurality of rotary targets by positioning the magnet so as to face the opposite side of the substrate from the inside,
rotating the magnets of the plurality of rotary targets about the central axis while supplying the discharge power to the plurality of rotary targets so that the magnets face the substrate side from the inside;
A film forming apparatus that controls sputtering film formation on the substrate while avoiding a reference position where the magnet is closest to the substrate. In the film forming apparatus according to claim 10,
When the rotation angle of the magnet when the magnet is positioned at the reference position is 0 degrees, and the counterclockwise rotation of the magnet is a positive rotation angle,
A film forming apparatus, wherein the rotation angle of the magnet from the reference position is set in the range of 30 degrees to 90 degrees, or in the range of -30 degrees to -90 degrees, and sputtering film formation is performed on the substrate. In the film forming apparatus according to claim 11,
A deposition apparatus in which the application of the discharge power to the plurality of rotary targets is cut off when the absolute value of the rotation angle is less than 30 degrees. In the film forming apparatus according to claim 11 or 12,
The film formation apparatus, wherein the rotation angle is set in the range of 100 degrees to 260 degrees when the magnet is opposed to the side opposite to the substrate from the inside and discharge power is applied to the plurality of rotary targets. In the film forming apparatus according to any one of claims 11 to 13,
Discharge power when the magnet faces the opposite side of the substrate from the inside is set to be smaller than discharge power when performing sputtering deposition on the substrate. In the film forming apparatus according to any one of claims 11 to 14,
The film deposition apparatus, wherein the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets are oriented in the same direction when sputtering deposition is performed on the substrate. In the film forming apparatus according to any one of claims 11 to 14,
The film deposition apparatus, wherein the rotation directions of the magnets of adjacent rotary targets among the plurality of rotary targets are directed in opposite directions when sputtering deposition is performed on the substrate. In the film forming apparatus according to any one of claims 11 to 16,
A film forming apparatus, wherein sputtering film formation is performed on the substrate at least once within the range of the rotation angle of 30 degrees to 90 degrees and at least once within the range of -30 degrees to -90 degrees. In the film forming apparatus according to any one of claims 11 to 17,
Sputtering onto the substrate at least once by oscillating the magnet within the range of the rotation angle of 30 degrees to 90 degrees and at least once by oscillating the magnet within the range of −30 degrees to −90 degrees Film deposition equipment where film deposition is performed.

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