WO2024142858A1 - Film forming device, film forming method, and method for manufacturing electronic device - Google Patents

Abstract

Provided is a film forming device that is able to form a film on a film forming object by sputtering using a rotary target composed of an alloy of two or more components. This film forming device includes: a cylindrical target composed of an alloy of two or more components; and a magnetic field generating means that is provided inside the target such that the angle about a rotational axis parallel to the center axis of the cylindrical shape is variable, and generates a stray magnetic field that strays from the outer circumferential surface of the target, wherein an alloy thin-film is formed by sputtering onto the film forming object disposed facing the target while the target is rotating. The film forming device is characterized in that the angle of the magnetic field generating means is controlled on the basis of information about the composition ratio of the alloy thin-film.

Description

Film forming apparatus, film forming method, and electronic device manufacturing method

The present invention relates to a film formation apparatus, a film formation method, and a method for manufacturing electronic devices that form a film on a substrate by sputtering.

As a deposition device for depositing a thin film of metal or metal oxide on a deposition target such as a substrate, there is a sputtering device that places a cylindrical target (hereafter referred to as a rotary target) facing the substrate and performs sputtering while rotating the rotary target. Compared to a planar-type sputtering device that uses a flat target, a sputtering device that uses a rotary target has the advantage that the surface of the target can be sputtered more uniformly. There is also a magnetron sputtering type sputtering device that places a magnet inside the rotary target and forms a magnetic field that leaks out of the rotary target, thereby increasing the plasma density near the surface of the rotary target (Patent Document 1).

An example of a thin film that can be formed by a sputtering device is a cathode metal film formed on the organic layer of an organic EL (electroluminescent) element. From the viewpoint of electron injection into the organic layer, alkali metals, alkaline earth metals, or alloys of these metals with low work functions such as Mg are preferable as components of the cathode metal film, but from the viewpoint of oxidation resistance, metals with high work functions such as Au, Ag, and Al are preferable. In order to achieve both electron injection and oxidation resistance, there is a cathode metal film formed of an alloy mainly composed of Mg and Ag (Patent Document 2). In Patent Document 2, two targets, a flat target made of Mg and a flat target made of Ag, are placed in a chamber, and a voltage is applied to both targets simultaneously to perform sputtering, forming a layer made of Mg-Ag alloy on the organic layer, and then a voltage is applied only to the Ag target to perform sputtering, forming a layer made of Ag on the Mg-Ag alloy layer, thereby forming a cathode metal film consisting of a multilayer film with a difference in the composition ratio of Mg and Ag in the thickness direction.

Patent document 3 describes a method for manufacturing a rotary target made of an Mg-Ag alloy.

JP 2020-200520 A JP 2004-200047 A JP 2013-204052 A

The sputtering device in Patent Document 2 uses multiple independent flat targets made of each component of the alloy, and there is no mention of a sputtering device using a rotary target made of an alloy. Patent Document 3 describes a rotary target made of a two-component alloy, but does not describe a sputtering device using it.

The present invention aims to provide a film formation device capable of forming a film on an object by sputtering using a rotary target made of an alloy of two or more components.

The present invention includes a cylindrical target made of an alloy of two or more components;
a magnetic field generating means provided inside the target such that an angle around a rotation axis parallel to the central axis of the cylindrical shape can be changed, the magnetic field generating means generating a leakage magnetic field leaking from an outer peripheral surface of the target;
having
A film formation apparatus for forming an alloy thin film by sputtering on a film formation target disposed opposite the target while rotating the target,
The film forming apparatus is characterized in that the angle of the magnetic field generating means is controlled based on information on the composition ratio of the alloy thin film.

The present invention includes a cylindrical target made of an alloy of two or more components;
a magnetic field generating means provided inside the target such that an angle around a rotation axis parallel to the central axis of the cylindrical shape can be changed, the magnetic field generating means generating a leakage magnetic field leaking from an outer peripheral surface of the target;
A film forming method using a film forming apparatus having the following features:
forming an alloy thin film by sputtering on a film-forming object disposed opposite the target while rotating the target;
controlling an angle of the magnetic field generating means based on information on the composition ratio of the alloy thin film;
The film forming method is characterized by having the following features.

The present invention makes it possible to provide a film formation device capable of forming a film on an object by sputtering using a rotary target made of an alloy of two or more components.

FIG. 2 is a diagram showing the configuration of an organic EL element according to an embodiment of the present invention. FIG. 2 is a diagram showing an in-line type film forming apparatus according to an embodiment. FIG. 2 is a diagram showing a cluster type film forming apparatus according to an embodiment. FIG. 2 is a schematic diagram showing the configuration of a substrate transport type sputtering apparatus according to an embodiment. FIG. 2 is a schematic diagram showing the configuration of a substrate transport type sputtering apparatus according to an embodiment. FIG. 2 is a schematic diagram showing the configuration of a magnet unit of the sputtering apparatus of the embodiment. FIG. 4 is a diagram for explaining the angle of a magnet unit of the sputtering apparatus of the embodiment. FIG. 2 is a schematic diagram showing the configuration of a rotating cathode unit moving type sputtering apparatus according to an embodiment. FIG. 2 is a schematic diagram showing the configuration of a twin cathode type sputtering apparatus according to the embodiment. FIG. 2 is a schematic diagram showing the configuration of a twin cathode type sputtering apparatus according to the embodiment. FIG. 4 is a diagram showing the angle of a magnet unit of a twin cathode type sputtering apparatus according to an embodiment. FIG. 4 is a diagram showing the angle of a magnet unit of a twin cathode type sputtering apparatus according to an embodiment. 5A to 5C are diagrams showing the swinging operation of the magnet unit of the sputtering apparatus of the embodiment. FIG. 4 is a diagram showing the relationship between the angle of the magnet unit of the sputtering device of the embodiment and the Mg composition ratio. FIG. 4 is a diagram showing the difference in deposition amount depending on the alloy components in the sputtering apparatus of the embodiment. FIG. 11 is a graph showing the relationship between the sputtering deposition time and the Mg composition ratio in Example 2. FIG. 13 is a graph showing the relationship between the sputtering deposition time and the Mg composition ratio in Example 3. FIG. 13 is a diagram showing a device region and an inspection region in a substrate according to a fourth embodiment.

Below, examples of the present invention are described in detail. However, the following examples merely exemplify preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. Furthermore, unless otherwise specified, the hardware and software configurations, process flows, manufacturing conditions, dimensions, materials, shapes, etc. of the device in the following description are not intended to limit the scope of the present invention to only those. Although multiple features are described in the examples, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined in any desired manner. Furthermore, in the accompanying drawings, the same reference numbers are used for identical or similar configurations, and duplicate explanations are omitted.

The film forming apparatus according to the present invention is used to deposit and form a thin film on a substrate (including a substrate on which a laminate is formed) in the manufacture of various electronic devices such as semiconductor devices, magnetic devices, and electronic components, and optical components. More specifically, the film forming apparatus according to the present invention is preferably used in the manufacture of electronic devices such as light-emitting elements, photoelectric conversion elements, and touch panels. In particular, it is particularly preferably applicable in the manufacture of organic light-emitting elements such as OLEDs (organic light-emitting diodes) and organic photoelectric conversion elements such as organic thin-film solar cells. The electronic device in the present invention also includes a display device (e.g., an organic EL (Electro-Luminescence) display device) and a lighting device (e.g., an organic EL lighting device) equipped with a light-emitting element, and a sensor (e.g., an organic CMOS image sensor) equipped with a photoelectric conversion element. In addition, the present invention also includes a manufacturing method for an electronic device having a process of forming a thin film on a substrate using a film forming apparatus according to each of the following embodiments or a film forming apparatus obtained by modifying the film forming apparatus of each embodiment within the scope of the present invention.

FIG. 1 shows a typical layer structure of an organic EL element that can be manufactured using the film forming apparatus of the following embodiment. An OLED generally has a structure in which an anode 61, an organic light-emitting layer 62, and a cathode 65 are laminated on a substrate 6. The film forming apparatus of the present invention is preferably used when forming a cathode 65 on the organic light-emitting layer 62. The cathode 65 is an alloy thin film made of two-component metal materials. The first component of the alloy constituting the cathode 65 is an alkali metal or alkaline earth metal with a low work function such as Mg, or an alloy thereof, from the viewpoint of electron injection into the organic light-emitting layer 62, and the second component is a metal with a high work function such as Au, Ag, or Al, from the viewpoint of oxidation resistance. In the following embodiment, the first component is Mg, and the second component is Ag.

The cathode 65 is preferably made of a multilayer film consisting of a first layer 63 and a second layer 64 formed on the first layer 63. This is because it is preferable to increase the Mg composition ratio on the side closer to the organic light-emitting layer 62 to increase electron injection properties, while it is preferable to increase the Ag composition ratio on the side closer to the external environment to increase oxidation resistance. By making the cathode 65 a multilayer film with different composition ratios, it is possible to achieve both electron injection properties and oxidation resistance. Thus, while the first layer 63 and the second layer 64 are both Mg-Ag alloys, the first layer 63 has a higher Mg composition ratio than the second layer 64, and the second layer 64 has a higher Ag composition ratio than the first layer 63. In other words, the cathode 65 is made of a multilayer film with different alloy composition ratios (having a gradient in the composition ratio) in the film thickness direction.

The alloy constituting the cathode 65 is not limited to this example, and may be another alloy mainly composed of a first component with excellent electron injection properties and a second component with excellent oxidation resistance. Examples of the first component include Li, Na, Mg, K, Ca, Cs, Yb, etc. Examples of the second component include Ag, Al, etc.

Furthermore, the film forming apparatus of the present invention is not limited to the formation of OLED cathodes or multilayer films in which the alloy composition ratio varies in the thickness direction, but can be generally applied to the formation of films made of alloys of two or more components. In particular, the present invention is not limited to the formation of cathodes made of multilayer films, but can also be applied to the formation of cathodes made of single-layer alloy thin films. Furthermore, the film forming apparatus of the present invention is not limited to the formation of films on organic films, but can form films on a variety of surfaces as long as the combination of materials that can be formed by sputtering, such as metal materials and oxide materials, is used.

The present invention can be applied to both an in-line type deposition apparatus as shown in FIG. 2 and a cluster type deposition apparatus as shown in FIG. 3.

2 is a schematic diagram showing a part of an in-line type film forming apparatus 100 in which multiple film forming chambers are connected. This film forming apparatus 100 has film forming chambers 101, 102, 103, and 104, and has an inspection chamber 105 downstream of the film forming chamber 104. In each film forming chamber, an anode 61, an organic light emitting layer 62, a first layer 63 of a cathode 65, and a second layer 64 of a cathode 65 are formed. The substrate 6 on which the film is formed in the film forming chamber 104 is carried into the downstream inspection chamber 105. The inspection chamber 105 is equipped with an inspection device (e.g., EPMA (electron probe microanalyzer)) capable of measuring the Mg composition ratio of the alloy thin film, and a composition analysis can be performed on the substrate 6 on which the Mg-Ag alloy thin film is formed in the film forming chamber 104. Note that both the first layer 63 and the second layer 64 constituting the cathode 65 may be formed in one film forming chamber.

FIG. 3 is a schematic diagram showing a part of a cluster-type film formation apparatus 111 in which multiple vacuum chambers are connected. In this film formation apparatus 111, a first cluster C1, a second cluster C2, and a third cluster C3 are connected in series. In addition to the film formation chambers 101 to 104, each cluster has known chambers such as a mask stocker as appropriate, but their description will be omitted here. An inspection chamber 105 is provided between the second cluster C2 and the third cluster C3. A composition analysis is performed in the inspection chamber 105 on the alloy thin film formed in the second cluster C2.

Each deposition chamber is equipped with a device that deposits films by sputtering or vapor deposition. Below, we will explain an example in which a sputtering device is installed.

(Substrate transport type sputtering device)
An example of a sputtering apparatus to which the present invention can be applied will be described with reference to Fig. 4. In the following description, the direction parallel to the transport direction S of the substrate 6 transported within the sputtering apparatus 1 is defined as the X direction, the direction parallel to the rotation axis of the cylindrical target 2 provided in the sputtering apparatus 1 is defined as the Y direction, and the vertical upward direction is defined as the Z direction. Fig. 4 is a diagram showing a schematic internal configuration of the sputtering apparatus 1 as viewed from the Y direction.

The sputtering apparatus 1 shown in FIG. 4 has a chamber 10 in which a substrate 6, which is a film-forming target, and a target 2 are placed. In the sputtering apparatus 1, the target 2 is placed vertically below the substrate 6, and film formation is performed by deposit-up with the film-forming surface of the substrate 6 facing vertically downward. Note that the present invention is not limited to this, and the target 2 may be placed vertically above the substrate 6, and film formation may be performed by deposit-down with the film-forming surface of the substrate 6 facing vertically upward. Alternatively, the substrate 6 may be set up vertically, and film formation may be performed with the film-forming surface of the substrate 6 parallel to the vertical direction.

The rotating cathode unit 8 has the target 2, which is a cylindrical rotary target, and a magnet unit 3, which is disposed in the hollow inside the target 2 and serves as a magnetic field generating means for generating a magnetic field around the outer periphery of the target 2. A backing tube 2a is provided inside the target 2. The rotating cathode unit 8 is fixed to the chamber 10, and the target 2 is supported by the chamber 10 so that it can rotate around the central axis of the cylinder. The target 2 rotates in the direction of arrow R as the driving force of the target drive device 11 is transmitted by a drive transmission means such as a gear. Arrow R is the clockwise direction in a cross section perpendicular to the Y direction shown in Figure 4.

The target 2 is made of a film-forming material for forming a film on the substrate 6 by sputtering, and functions as a supply source of the film-forming material. Here, an example will be described in which a cathode 65 (upper electrode) made of an Mg-Ag alloy is formed by sputtering on the substrate 6 on which the anode 61 and organic light-emitting layer 62 of the OLED shown in FIG. 1 have already been formed. Therefore, the material that constitutes the target 2 is a two-component alloy of Ag and Mg.

A layer of the film-forming material for the target 2 is formed on the outside of the backing tube 2a. The backing tube 2a is connected to a power source 13 and functions as a cathode to which a negative voltage is applied from the power source 13. The voltage may be applied directly to the target 2, in which case the backing tube 2a may not be provided. The power source 13 may be a DC power source, an AC power source, or a high-frequency power source depending on the material of the target 2. The chamber 10 is grounded. The target 2 is a cylindrical target, but the term "cylindrical" does not only mean a mathematically strict cylindrical target, but also includes targets whose generatrix is not a straight line but a curved line, and targets whose cross section perpendicular to the central axis is not a mathematically strict "circle". In other words, the target 2 in the present invention may be a cylindrical target that can rotate around the central axis.

The magnet unit 3 creates a magnetic field on a portion of the surface side of the target 2. The magnet unit 3 is provided inside the target 2 with a variable angle around a central axis parallel to the central axis of the cylindrical shape of the target 2. The magnet unit 3 is supported so that it can rotate about the central axis. The driving force of the magnet drive device 110 is transmitted by a drive transmission means such as a gear, and the magnet unit 3 rotates in a clockwise and counterclockwise direction in a cross section perpendicular to the Y direction shown in FIG. 4, as indicated by the arrow M. The magnet unit 3 can be stationary at any angle. The rotation of the target 2 by the target drive device 11 and the rotation of the magnet unit 3 by the magnet drive device 110 are controlled independently.

The substrate 6 is loaded through one of the gate valves 17 provided on the side wall of the chamber 10. The substrate 6 is transported horizontally (in the direction indicated by the arrow S) within the chamber 10 by the transport member 120 while a film is formed by sputtering. After a film is formed on the entire film-forming surface of the substrate 6, the substrate 6 is loaded through the gate valve 18 provided on the other side wall of the chamber 10.

Gas introduction means 16 and exhaust means 15 are connected to chamber 10, and the pressure inside can be adjusted to a predetermined level. A sputtering gas (an inert gas such as argon or a reactive gas such as oxygen or nitrogen) is introduced into chamber 10 by gas introduction means 16 through an inlet 41 provided in chamber 10. Air is exhausted from the inside of chamber 10 through exhaust port 5 by exhaust means 15, such as a vacuum pump. This allows the pressure inside chamber 10 to be adjusted to a predetermined level.

The gas introduction means 16 has an inlet 41 and is composed of a supply source such as a gas cylinder (not shown), a piping system connecting the supply source and the inlet 41, and various vacuum valves, mass flow controllers, etc. provided in the piping system, and the supply amount can be adjusted by a flow control valve of the mass flow controller. The flow control valve has an electrically controllable configuration such as an electromagnetic valve. The inlet 41 is disposed on a vertical side wall of the chamber 10. Note that the installation position of the inlet 41 is not limited to the side wall, and it may be disposed on the bottom wall or the ceiling wall. Also, the piping may extend into the chamber 10, and the inlet may open into the chamber 10. Also, a configuration in which multiple inlets 41 are provided and arranged along the rotation axis direction of the target 2 may be used.

The exhaust means 15 has a vacuum pump and a piping system that connects the vacuum pump and the exhaust port 5. The piping system is provided with an electrically controllable flow control valve such as a conductance valve, and the exhaust volume can be adjusted by the control valve. The exhaust port 5 is provided in the bottom wall of the chamber 10. Note that the installation position of the exhaust port 5 is not limited to the bottom wall, and it may be provided in a vertical side wall or in the ceiling wall. Also, the piping may extend into the chamber 10, and the exhaust port 5 may open into the chamber 10.

The control unit 14 controls the target driving device 11 to drive and rotate the target 2 in the direction of the arrow R while keeping the angle of the magnet unit 3 fixed, and controls the power supply 13 to apply a negative voltage to the target 2. When a voltage is applied to the target 2, the region where the magnetic field generated by the magnet unit 3 exists becomes the sputtering region A where plasma is concentrated and sputtered particles are generated. During the film formation process, the magnet unit 3 is stationary relative to the chamber 10, so the opposing angle between the sputtering region A and the film formation target surface of the substrate 6 is constant during the film formation process. The positive ionized inert gas ions in the plasma collide with the surface of the target 2, and the atoms and molecules of the material that constitutes the target 2 are ejected from the target 2. The particles of the film formation material ejected from the target 2 adhere to and accumulate on the film formation target surface of the substrate 6.

Here, the opposing angle between the sputtering area A and the film-forming surface of the substrate 6 is defined as, for example, the angle between a line segment that bisects the central angle of the arc corresponding to the sputtering area A on the cylindrical surface of the target 2, within a virtual plane perpendicular to the rotation axis of the target 2, and a virtual plane that includes the film-forming surface of the substrate 6.

As the substrate 6 moves horizontally (indicated by arrow S) by the transport member 120, the film formation target area on the substrate 6 facing the sputtering area A moves horizontally. As a result, a film is formed on the film formation target surface of the substrate 6 sequentially from the downstream end to the upstream end in the transport direction S. As a result, sputtering film formation is performed uniformly over the entire surface of the substrate 6.

The area on the surface of the target 2 from which the sputtered particles are emitted moves in the circumferential direction as the target 2 rotates. Therefore, when focusing on a localized area on the surface of the target 2, sputtering occurs intermittently at a period determined by the rotation speed of the target 2.

FIG. 5 is a schematic diagram showing the internal configuration of the sputtering apparatus 1 as viewed from the X direction. The Y direction ends of the target 2 are rotatably supported by a support block 210 and an end block 220. The support block 210 and the end block 220 are provided with a power transmission mechanism that transmits the driving force from the target drive device 11, which is a rotation drive device, to the target 2. The target drive device 11 has a drive source such as a motor, and drives the target 2 to rotate via the power transmission mechanism.

Figure 6 is a schematic diagram showing the configuration of the magnet unit 3 provided inside the target 2. The magnet unit 3 includes a central magnet 31 extending parallel to the rotation axis of the target 2, a peripheral magnet 32 that surrounds the central magnet 31 and has a polarity opposite to that of the central magnet 31, and a yoke plate 33. The peripheral magnet 32 is composed of a pair of straight portions 32a and 32b extending parallel to the central magnet 31, and turning portions 32c and 32d that connect both ends of the straight portions 32a and 32b. The magnetic field formed by the magnet unit 3 has magnetic field lines that loop back from the magnetic pole of the central magnet 31 to the straight portions 32a and 32b of the peripheral magnet 32. As a result, a toroidal magnetic field tunnel extending in the direction of the rotation axis of the target 2 is formed near the surface of the target 2. This magnetic field captures electrons and concentrates plasma near the surface of the target 2, thereby increasing the efficiency of sputtering. The magnetic field of this magnet unit 3 creates a high-density plasma, and the area where sputtered particles are concentrated is called sputtering area A.

The magnet unit 3 is fixed on a base 34, and a rotation shaft 35 is fixed to the base 34. The rotation shaft 35 extends parallel to the central axis of the cylindrical target 2, rotatably supports the base 34 relative to the chamber 10, and rotates by the driving force of the magnet drive device 110. As a result, the magnet unit 3 is supported rotatably relative to the central axis, and the angle around the rotation shaft 35 parallel to the cylindrical central axis of the target 2 is set to be variable. The rotational movement of the magnet unit 3 is performed by the driving force of the magnet drive device 110. The magnet drive device 110 is configured to rotate the magnet unit 3 to any angle and to stop it at that angle. This makes it possible to perform operations such as performing sputtering with the magnet unit 3 stationary during the film formation process, oscillating the magnet unit 3 during the film formation process as described below, and changing the angle of the magnet unit 3 to control the composition ratio when the film formation process is not being performed. In the sputtering device 1, an example has been described in which the central axis of the rotation shaft 35 coincides with the central axis of the target 2, but the central axis of the rotation shaft 35 may be parallel to the central axis of the target 2. The driving force of the magnet driving device 110 is transmitted to the rotation shaft 35 via a power transmission mechanism (not shown). The magnet driving device 110 has a driving source such as a motor.

Figure 7 shows the relative positions of the substrate 6, target 2, and magnet unit 3 when a cylindrical target 2 is used to perform sputtering film deposition on the vertically lower surface of a substrate 6 placed above the target 2 using a deposition-up method.

When sputtering gas ions (e.g., Ar ⁺ ) generated by applying a negative voltage to the target 2 collide with the surface of the target 2, atoms and molecules of the film-forming material that constitutes the target 2 are emitted as sputtered particles from the target 2. The location and direction in which these emitted materials (sputtered particles) are emitted from the surface of the target 2 during sputtering can be set by the magnetic field formed in the vicinity of the surface of the target 2 by the magnet unit 3.

In FIG. 7, the center of rotation O of the target 2 and the center of rotation of the rotation axis 35 of the magnet unit 3 coincide with each other. Sputtered particles are generated in a concentrated manner in the sputtering region A, which is defined by the positions of the line segments D2 and D3 passing through the center of rotation of the rotation axis 35 of the magnet unit 3 and the position between the central magnet 31 and the peripheral magnet 32. The sputtering region A may be an area determined based on the magnetic flux distribution of the magnetic field formed by the magnet unit 3. It may also be an area on the surface of the target 2 where the magnetic field strength has a certain value or higher. It may also be determined based on the arrangement and structure of the magnets of the magnet unit 3, the position where the sputtered particles are generated in a concentrated manner, and phenomena generally, statistically, empirically, or experimentally observed as the direction in which the material is emitted from the surface of the target 2 during sputtering.

The angle θ of the line segment D1 passing through the center of rotation of the rotation axis 35 of the magnet unit 3 and the center of the sputtering area A is defined as the angle of the magnet unit 3. The angle θ of the magnet unit 3 is an angle based on the position where the line segment D1 is perpendicular to the film formation target surface of the substrate 6 (when the magnet unit 3 is located at the position shown by the dashed line in Figure 7), and the clockwise direction in Figure 7 is defined as positive.

(Moving cathode sputtering device)
Another example of a sputtering apparatus to which the present invention can be applied will be described with reference to Fig. 8. Elements common to the above-mentioned substrate conveying type sputtering apparatus will be designated by common names and symbols and detailed description thereof will be omitted.

The sputtering apparatus 1X shown in FIG. 8 is a sputtering apparatus in which a substrate 6 is fixed to a chamber 10 and a rotating cathode unit 8X can move back and forth within the chamber 10. FIG. 8 is a schematic diagram showing the internal configuration of the sputtering apparatus 1X as viewed from a direction parallel to the rotation axis of a cylindrical target 2 provided in the sputtering apparatus 1X (Y direction).

In the sputtering apparatus 1 of FIG. 4, the rotating cathode unit 8 does not move relative to the chamber 10, and the substrate 6 moves relative to the chamber 10, so that a film is formed on the target surface of the substrate 6, starting from the downstream end in the transport direction of the substrate 6. In the sputtering apparatus 1X of FIG. 8, the rotating cathode unit 8X moves relative to the chamber 10, and the substrate 6 does not move relative to the chamber 10, so that a film is formed on the target surface of the substrate 6, starting from the upstream end in the movement direction of the rotating cathode unit 8X.

The rotating cathode unit 8X has a movable stage 230, and the movable stage 230 is provided with a partition member 260 arranged around the target 2. The partition member 260 opens in the direction in which the substrate 6 is arranged (vertically upward).

The movable stage 230 is supported so as to be freely movable in the horizontal direction (indicated by the arrow T) along a pair of guide rails 250 via a transport guide such as a linear bearing. The guide rails 250 are provided parallel to the X direction. The movable stage 230 is linearly driven in the X direction by the linear drive device 12. The linear drive device 12 can be any of a variety of known linear motion mechanisms, such as a screw feed mechanism using a ball screw or the like that converts the rotational motion of a rotary motor into linear motion, or a linear motor. Therefore, the rotating cathode unit 8X moves in the X direction within the XY plane, and the target 2 moves in the X direction within the XY plane while rotating around a rotation axis parallel to the Y direction.

When the substrate 6 is loaded into the chamber 10, it is held by the holder 6a vertically above the rotating cathode unit 8X. During the film formation process, the substrate 6 does not move relative to the chamber 10, and the film is formed by sputtering while the rotating cathode unit 8X moves horizontally (in the direction indicated by the arrow T). After the film is formed on the entire film formation target surface of the substrate 6, the substrate 6 is unloaded through a gate valve 18 provided on the other side wall of the chamber 10.

When forming a film by sputtering in the sputtering device 1X, the control unit 14 controls the target driving device 11 to rotate the target 2 in the direction of the arrow R, and controls the power supply 13 to apply a negative voltage to the target 2.

The rotating cathode unit 8X is moved in the direction of arrow T relative to the chamber 10 by the linear drive device 12, so the sputtering area A moves in the direction of arrow T relative to the chamber 10. In addition, the magnet unit 3 does not rotate together with the target 2 during the film formation process, so the opposing angle between the sputtering area A and the film formation target surface of the substrate 6 remains constant during the film formation process. During the film formation process, the substrate 6 is held by the holder 6a and does not move relative to the chamber 10.

As the rotating cathode unit 8X moves horizontally by the linear drive device 12, the sputtering area A of the target 2 moves relative to the chamber 10 along the film-forming surface of the substrate 6 in conjunction with the movement of the rotating cathode unit 8X. As a result, a film is sequentially formed on the film-forming surface of the substrate 6 from the upstream end to the downstream end of the moving direction T of the rotating cathode unit 8X as the rotating cathode unit 8X moves.

(Twin cathode type sputtering device)
Another example of a sputtering apparatus to which the present invention can be applied will be described with reference to Figures 9 and 10. Elements common to the above-mentioned single cathode type sputtering apparatuses 1 and 1X will be given common names and symbols and detailed descriptions thereof will be omitted.

Figure 9 is a schematic diagram showing the internal configuration of sputtering apparatus 1Y as viewed from a direction parallel to the rotation axis of cylindrical second target 2R provided in sputtering apparatus 1Y (Y direction). Figure 10 is a schematic diagram showing the internal configuration of sputtering apparatus 1Y as viewed from a direction parallel to the movement direction T of rotating cathode unit 8Y moving within sputtering apparatus 1Y (X direction).

In the sputtering apparatus 1Y of FIG. 9, similar to the sputtering apparatus 1X of FIG. 8, the rotating cathode unit 8Y moves relative to the chamber 10, the substrate 6 does not move relative to the chamber 10, and a film is formed on the target surface of the substrate 6, starting from the upstream end in the direction of movement of the rotating cathode unit 8Y.

The rotating cathode unit 8 of the sputtering apparatus 1 in Figure 4 was composed of a cylindrical target 2 and a magnet unit 3, while the rotating cathode unit 8Y of the sputtering apparatus 1Y in Figure 9 is composed of a cylindrical first target 2L, a first magnet unit 3L which is a first magnetic field generating means that is arranged inside the first target 2L at a variable angle about a rotation axis parallel to the central axis of the cylinder and generates a leakage magnetic field leaking from the outer peripheral surface of the first target 2L, a cylindrical second target 2R, and a second magnet unit 3R which is a second magnetic field generating means that is arranged inside the second target 2R at a variable angle about a rotation axis parallel to the central axis of the cylinder and generates a leakage magnetic field leaking from the outer peripheral surface of the second target 2R. The configurations of the first target 2L and the first magnet unit 3L, and the configurations of the second target 2R and the second magnet unit 3R are similar to the configurations of the target 2 and the magnet unit 3 of the sputtering device 1 in FIG. 4, but the rotation directions of the first target 2L and the second target 2R by the target driving device 11Y are opposite to each other. The first target 2L rotates in the direction of arrow L, and the second target 2R rotates in the direction of arrow R, which is opposite to the direction of arrow L. The first magnet unit 3L and the second magnet unit 3R rotate as shown by the arrows ML and MR by the driving force of the magnet driving device 110Y.

The configuration in which the rotating cathode unit 8Y can move within the chamber 10 is the same as that of the sputtering apparatus 1X in FIG. 8. The rotating cathode unit 8Y has a moving stage 230, and a support block 210 and an end block 220 that rotatably support the first target 2L and the second target 2R. On the moving stage 230, the first target 2L and the second target 2R are arranged side by side in the moving direction T (parallel to the X direction) of the rotating cathode unit 8Y. The moving stage 230 is provided with a partition member 260 arranged to surround the first target 2L and the second target 2R. Note that in FIG. 10, the partition member 260 is omitted to avoid complexity. The partition member 260 is open in the direction in which the substrate 6 is arranged (vertically upward).

When forming a film by sputtering in the sputtering device 1Y, the control unit 14 controls the target driving device 11Y to rotate the first target 2L and the second target 2R in the directions of the arrows L and R, respectively, and controls the power supply 13 to apply a negative voltage to the first target 2L and the second target 2R. The manner in which a film is formed by sputtering is the same as in the sputtering device 1X of FIG. 8.

FIG. 11 is a diagram showing the positional relationship of the first magnet unit 3L, the second magnet unit 3R, the first target 2L, the second target 2R, and the substrate 6 of the sputtering device 1Y in FIG. 9. In FIG. 11, the rotation center O of the first target 2L and the rotation center of the rotation axis 35L of the first magnet unit 3L coincide. Sputter particles are generated intensively in the sputtering area AL defined by the positions of the line segments D2L and D3L passing through the rotation center of the rotation axis 35L of the first magnet unit 3L and the position between the central magnet 31L and the peripheral magnet 32L. In addition, the rotation center O of the second target 2R and the rotation center of the rotation axis 35R of the second magnet unit 3R coincide. Sputter particles are generated intensively in the sputtering area AR defined by the positions of the line segments D2R and D3R passing through the rotation center of the rotation axis 35R of the second magnet unit 3R and the position between the central magnet 31R and the peripheral magnet 32R.

The angle θL of the line segment D1L passing through the center of rotation of the rotation shaft 35L of the first magnet unit 3L and the center of the sputtering area AL is defined as the angle of the first magnet unit 3L. The angle θR of the line segment D1R passing through the center of rotation of the rotation shaft 35R of the second magnet unit 3R and the center of the sputtering area AR is defined as the angle of the second magnet unit 3R. The angles θL and θR of the first magnet unit 3L and the second magnet unit 3R are angles based on the position where the line segments D1L and D1R are perpendicular to the film formation target surface of the substrate 6 (when the first magnet unit 3L and the second magnet unit 3R are at the position shown by the dashed line in Figure 11), and the clockwise direction in Figure 11 is defined as positive.

The first target 2L and the second target 2R are made of an Mg-Ag alloy of the same composition, and the angles θL and θR of the first magnet unit 3L and the second magnet unit 3R are equal. In other words, the line segment D1L of the first magnet unit 3L and the line segment D1R of the second magnet unit 3R face in the same direction.

As shown in FIG. 12, the angles θL and θR of the first magnet unit 3L and the second magnet unit 3R may be set to have the same absolute value but opposite signs. In this case, the line segment D1L of the first magnet unit 3L and the line segment D1R of the second magnet unit 3R are oriented symmetrically in the movement direction T (X direction) of the rotating cathode unit 8Y.

The outer diameter of the first target 2L and the second target 2R was 140 mm, and the distance between the centers of the first target 2L and the second target 2R was 300 mm.

Note that the twin cathode sputtering apparatus 1Y in FIG. 9 is a rotating cathode unit moving type sputtering apparatus equipped with two cathodes, but the present invention can also be applied to a twin cathode sputtering apparatus equipped with two cathodes in a substrate transport type sputtering apparatus such as the sputtering apparatus 1 in FIG. 4.

(Swinging magnet unit type sputtering device)
Another example of a sputtering apparatus to which the present invention can be applied will be described with reference to Fig. 13. Elements common to the above-mentioned single cathode type sputtering apparatus 1 will be given the same names and reference numerals and detailed description will be omitted.

In the sputtering apparatus 1 of FIG. 4, an example is shown in which the angle θ of the magnet unit 3 is adjusted before the start of film formation, and the magnet unit 3 is stationary at the adjusted angle θ during the film formation process. In contrast, the magnet unit 3 may be oscillated within a small angle range forward and backward around the adjusted angle θ during the film formation process.

FIG. 13 is a diagram showing the operation when the magnet unit 3 is oscillated. In FIG. 13, the magnet unit 3 shown by the solid line is at a position of angle θ determined before the start of film formation, as shown by line segment D1. As shown by the dashed line, during the film formation process, the magnet unit 3 continues to move so as to oscillate (swing) between a first position shown by line segment D11 and a second position shown by line segment D12 within a range of angle δ centered on the position of angle θ. In other words, during the film formation process, line segment D1 of the magnet unit 3 oscillates in the range of θ-δ/2 degrees to θ+δ/2 degrees. This makes it possible to uniformize deposition unevenness caused by the shape and arrangement of the magnets such as the central magnet 31 and peripheral magnets 32 that make up the magnet unit 3.

As described below, the angle θ of the magnet unit 3 affects the composition ratio of the alloy thin film that is formed, so it is preferable that the angle δ of the oscillation range is small. For example, the oscillation range is set to within ±5 degrees around the initial angle θ. In this case, during the film formation process, the magnet unit 3 oscillates in the range of θ-5 degrees to θ+5 degrees.

(Relationship between Mg composition ratio and angle of magnet unit)
Next, control of the Mg composition ratio by adjusting the angle of the magnet unit, which is a feature of the present invention, will be described.

In this embodiment, a cylindrical sputtering target made of an alloy material of Ag and Mg was used as target 2. The Mg composition ratio of the Mg-Ag alloy target was approximately 10 vol. %.

The manufacturing method of target 2 will be explained. After melting and alloying Ag with a purity of 99.9% or more and Mg with a purity of 99.9% or more, the molten metal was dropped from the bottom of the crucible and an inert gas such as argon was sprayed onto it to produce atomized Mg-Ag alloy powder. The particle size of the atomized powder was set to 1 μm or more and 1000 μm or less. The atomized powder was sprayed onto a backing tube 2a together with a high-velocity inert gas to produce a cylindrical target 2 made of Mg-Ag alloy. Stainless steel (SUS304, SUS630, etc.) or titanium can be used for the backing tube 2a.

In this embodiment, an Mg-Ag alloy target is used, but alloys or compounds containing Cu, Al, Ti, Mo, Cr, Ag, Au, Ni, etc. may be used depending on the purpose. When used as an OLED cathode, examples of the first component include Li, Na, Mg, K, Ca, Cs, Yb, etc. Examples of the second component include Ag and Al. The manufacturing method of the Mg-Ag alloy target is not limited to spraying atomized powder, and it can be manufactured by any method such as casting, thermal spraying, sintering, etc.

The cylindrical target 2 made of the prepared Mg-Ag alloy was placed in the sputtering device 1, and a film was formed on the substrate 6. A magnet unit 3 was placed inside the target 2 (inside the backing tube 2a in the sputtering device 1 in Figure 4), and the orientation of this magnet unit 3 could be changed to any angle. Before starting the film formation, the magnet unit 3 was adjusted to a specified angle θ, and sputtering film formation was performed with the target 2 rotating at 10 rpm while keeping the angle fixed.

The Ar gas pressure during sputtering deposition was 0.6 Pa, and the temperature of the substrate 6 was room temperature. Film deposition was performed by transporting the substrate 6 above the target 2 at a predetermined speed in the direction indicated by the arrow S (see Figure 7).

The composition of the deposited alloy thin film was analyzed by X-ray fluorescence. Here, the composition was analyzed by X-ray fluorescence, but other methods for analyzing the composition of alloy thin films can be used, such as XRF (X-ray fluorescence), EDS (energy dispersive X-ray spectroscopy), EPMA (electron probe microanalyzer), XPS (X-ray photoelectron spectroscopy), SIMS (secondary ion mass spectrometry), GDMS (glow discharge mass spectrometry), and ICP (inductively coupled plasma mass spectrometry). Other methods that can be used include transmission spectrometry, reflection spectrometry, emission spectrometry, and spectroscopic ellipsometry.

In the course of intensive research, the inventors found that when the angle θ of the magnet unit 3 in the backing tube 2a was changed to various angles to form a film, the Mg composition ratio of the formed alloy thin film changed depending on the angle θ. For example, when the angle θ of the magnet unit 3 was set to 0 degrees to form a film, the Mg composition ratio was 7.9 vol. %. On the other hand, when the angle θ of the magnet unit 3 was tilted to 20 degrees and 40 degrees to form a film, the Mg composition ratio was 8.4 vol. % and 9.4 vol. %, respectively. The results are shown in FIG. 14. In FIG. 14, the horizontal axis represents the angle θ of the magnet unit 3, and the vertical axis represents the Mg composition ratio of the formed alloy thin film. As shown in the results, the larger the angle θ of the magnet unit 3, the larger the Mg composition ratio of the Mg-Ag alloy thin film was obtained. That is, the magnet unit 3 of this embodiment is configured so that the larger the angle from the reference position (θ = 0 degrees) is, the larger the Mg composition ratio of the alloy thin film becomes. The fact that the Mg composition ratio of the Mg-Ag alloy thin film shows this tendency is a new finding obtained by the inventors through extensive research. Based on this finding, this embodiment is characterized by controlling the Mg composition ratio of the Mg-Ag alloy thin film by adjusting the angle θ of the magnet unit 3.

The inventors verified the above-mentioned relationship between the angle θ of the magnet unit 3 and the Mg composition ratio of the Mg-Ag alloy thin film from the following viewpoints. The angle θ of the magnet unit 3 was set to 0 degrees, and the substrate 6 was placed stationary directly above the cylindrical target 2 to perform sputtering, and the deposition amount distribution of Ag and Mg on the substrate 6 was examined. The results are shown in Figure 15. In Figure 15, the horizontal axis represents the distance from the position where the deposition amount (film thickness) is the largest on the substrate 6 (hereinafter referred to as the maximum film thickness position). In this embodiment, the maximum film thickness position is the intersection position of the line segment D1 and the substrate 6 when θ = 0 in Figure 7, and is the position closest to the rotation center O of the target 2. The vertical axis represents the film thickness normalized by the film thickness at the maximum film thickness position. As shown in Figure 15, the film thickness of both Mg and Ag became smaller as it moved away from the maximum film thickness position. In addition, the change (decrease) in film thickness due to the distance from the maximum film thickness position was more gradual for Mg than for Ag. That is, the deposition amount distribution of Mg has a mountain-like shape with a wider width and a lower peak compared to the deposition amount distribution of Ag. This indicates that the composition ratio of Mg is relatively higher at the wide-angle position (position farther away from the maximum film thickness position) than at the maximum film thickness position, which is consistent with the result that the Mg composition ratio increases when the angle θ of the magnet unit 3 is increased during transport and deposition as described above.

In this way, in magnetron rotary sputtering deposition using an Mg-Ag alloy target, the Mg composition ratio of the deposited alloy thin film can be controlled by changing the angle θ of the magnet unit 3. Based on this knowledge, by controlling the sputtering device 1 and the sputtering deposition process, it is possible to stably form an Mg-Ag alloy thin film with the desired Mg composition ratio.

Note that changing the angle θ of the magnet unit 3 changes not only the composition ratio but also the film thickness (film formation rate), but the desired film thickness can be obtained by adjusting the voltage applied to the target 2 and the height of the magnet.

The above findings are not limited to Mg-Ag alloy targets, but can also be applied to magnetron rotary sputtering devices using alloy targets composed mainly of two types of materials that have different tendencies in the change in film thickness depending on the distance from the maximum film thickness position when magnetron rotary sputtering is performed, as shown in FIG. 15. That is, the target 2 is made of an alloy of two or more components, and when a film is formed on a film-forming object using the target 2, the combination of the two components is sufficient so that the deposition amount distribution of the first component has a mountain-shaped shape that is wider and has a lower peak than the deposition amount distribution of the second component. If the magnet unit 3 is configured so that the composition ratio of the first component of the alloy thin film increases as the angle from the reference position (the position of θ=0 degrees) increases, the control unit 14 increases the angle θ of the magnet unit 3 when the composition ratio of the first component is increased, and decreases the angle θ of the magnet unit 3 when the composition ratio of the first component is decreased, based on the composition ratio information of the alloy thin film.

In addition, as in this embodiment, when the magnet unit 3 is configured and the angle θ is defined such that the composition ratio of Mg (first component) increases as the absolute value of the angle from the reference position increases, the control unit 14 increases the absolute value of the angle θ of the magnet unit 3 when the composition ratio of Mg (first component) is to be increased based on the composition ratio information of the alloy thin film, and decreases the absolute value of the angle θ of the magnet unit 3 when the composition ratio of Mg (first component) is to be decreased.

Depending on various conditions such as the shape, arrangement, and magnetic properties of each magnet constituting the magnet unit 3, the arrangement of the magnet unit 3 within the target 2, the components and composition ratio of the alloy constituting the target 2, the definition of the angle θ of the magnet unit 3, and the positional relationship between the target 2 and the substrate 6, it is possible that the relationship between the angle θ of the magnet unit 3 and the Mg composition ratio will not necessarily be the same as the relationship illustrated in FIG. 14. Even in such cases, the idea disclosed in this invention makes it possible to control the Mg composition ratio with high precision by using the relationship between the angle θ of the magnet unit 3 and the Mg composition ratio in the actual sputtering apparatus 1 and adjusting the angle θ of the magnet unit 3 based on the composition ratio information of the alloy thin film to be formed.

<Specific control examples>
When forming a film by sputtering in the sputtering apparatus 1, the control unit 14 acquires information on the composition ratio of the alloy thin film to be formed on the substrate 6 from the composition ratio acquisition unit 130. Examples of information acquired by the composition ratio acquisition unit 130 include information on the target composition ratio of the alloy thin film to be formed on the substrate 6, information on the composition ratio of the alloy material constituting the target 2, information on the composition ratio measured by an inspection device installed outside the sputtering apparatus 1 for alloy thin films previously formed in the sputtering apparatus 1, information on the relationship between the angle of the magnet unit 3 and the composition ratio, information on the change in the composition ratio due to the passage of time or the number of films formed when continuous film formation is performed for a long period of time, etc. Examples of methods by which the composition ratio acquisition unit 130 acquires information on these composition ratios include input of information by a user, acquisition of information via a wired or wireless communication path from an external measuring device or experimental device, acquisition of information via a recording medium, acquisition of information by reading an optical identification pattern, etc.

The control unit 14 adjusts the angle of the magnet unit 3 before starting film formation based on information about such composition ratio. Below, we will explain several examples of the method of controlling the composition ratio by adjusting the angle of the magnet unit 3, which is characteristic of the present invention.

Example 1
As an example of angle control of the magnet unit 3 based on the composition ratio information, a control for adjusting the angle θ of the magnet unit 3 according to the target Mg composition ratio for film formation and the Mg composition ratio of the target 2 can be considered. The relationship between the angle θ of the magnet unit 3 and the Mg composition ratio can be a result measured in advance by an experiment or the like as shown in Fig. 14. The control unit 14 determines the angle θ of the magnet unit 3 during actual film formation based on the target Mg composition ratio, the Mg composition ratio of the target 2, and the previously obtained relationship between the angle θ of the magnet unit 3 and the Mg composition ratio.

For example, consider the case where the Mg-Ag alloy thin film of the first layer 63 of the cathode 65 is deposited by magnetron rotary sputtering. The Mg composition ratio of the target 2 is set to 10 vol. %, and the target value of the Mg composition ratio of the first layer 63 is set to 9 vol. %. In this case, from the graph in Figure 14, it is possible to form the first layer 63 with the target Mg composition ratio by depositing the film with the angle θ of the magnet unit 3 set to about 30 degrees.

In addition, the Mg composition ratio of the first layer 63 that has actually been deposited can be analyzed and measured, and the angle θ of the magnet unit 3 can be fine-tuned based on the results to adjust the Mg composition ratio closer to the target value. For example, the angle θ of the magnet unit 3 can be adjusted so that the difference between the Mg composition ratio and the target value is 0.5% or less.

Example 2
A possible method for controlling the angle of the magnet unit 3 based on the composition ratio information is to feed back information on the Mg composition ratio of the thin film formed on the preceding substrate 6. In this control, when performing continuous film formation on a plurality of substrates 6, the angle θ of the magnet unit 3 is periodically adjusted to maintain the Mg composition ratio at a target value for a long period of time.

First, the first film is formed with the magnet unit 3 in the cylindrical target 2 facing vertically upward (angle θ = 10 degrees). The Mg-Ag alloy thin film formed in this first film is subjected to composition analysis using X-ray fluorescence to measure the first Mg composition ratio. The angle θ of the magnet unit 3 is changed based on the difference information between the first Mg composition ratio and the target Mg composition ratio. After changing the angle θ of the magnet unit 3, the second film is formed. By appropriately changing the angle θ of the magnet unit 3, the Mg composition ratio of the Mg-Ag alloy thin film obtained in the second film formation can be made closer to the target Mg composition ratio.

For example, if the target value of the Mg composition ratio is 9 vol. %, and the Mg composition ratio of the alloy thin film obtained by the first film formation is 8.4 vol. %, the angle θ of the magnet unit 3 is changed, for example, in a direction to increase by 10 degrees based on the information on the difference between this measurement evaluation value and the target value, and the second film formation is performed. The amount of change in the angle θ of the magnet unit 3 can be determined based on the relationship between the angle θ of the magnet unit 3 and the Mg composition ratio as shown in FIG. 14, which has been evaluated in advance by experiments, etc. The relationship between the angle θ of the magnet unit 3 and the Mg composition ratio is stored in the memory of the control unit 14 as a function or table. The amount of change in the angle θ of the magnet unit 3 can be calculated based on the relationship read from the memory and the difference between the target value obtained by measurement and the measurement evaluation value. In this way, the Mg composition ratio of the alloy thin film obtained by the second film formation performed after changing the angle θ of the magnet unit 3 approaches the target value (for example, 8.9 vol. %).

In this way, by repeating film formation, composition analysis, and adjustment of the angle θ of the magnet unit 3 (i.e., by feedback-controlling the angle θ of the magnet unit 3 based on composition evaluation information), it is possible to obtain an Mg-Ag alloy thin film with the target Mg composition ratio. In a continuous manufacturing process lasting for a long period of time (several hundred hours), the Mg composition ratio may vary over time, but even in such cases, by periodically adjusting the angle θ of the magnet unit 3 as described above, it is possible to stably form an alloy thin film with an Mg composition ratio close to the target over a long period of time.

Figure 16 shows the change over time in the Mg composition ratio of an alloy thin film obtained in a long-term continuous manufacturing process. The solid line graph A shows the case where feedback control of the angle θ of the magnet unit 3 is performed, and the dashed line graph B shows the case where the angle θ of the magnet unit 3 is fixed. As shown in Figure 16, when the angle θ of the magnet unit 3 is feedback controlled, the Mg composition ratio can be maintained stably for a long period of time during film formation.

The interval for adjusting the angle θ of the magnet unit 3 may be adjusted for each substrate on which a film is formed, or the angle θ of the magnet unit 3 may be feedback-controlled every time a film is formed on a predetermined number of substrates (e.g., every 100 substrates). The angle θ of the magnet unit 3 may also be feedback-controlled every time a film is formed for a predetermined period of time (e.g., every 50 hours). When the angle θ of the magnet unit 3 is changed, the film formation time or input power may be adjusted at the same time. By adjusting the film formation time or input power, not only the Mg composition ratio but also the film thickness can be maintained constant when forming a thin film.

Example 3
As an example of controlling the angle of the magnet unit 3 based on the composition ratio information, a control that feeds forward information on the change in the composition ratio obtained from a film formation test before the start of film formation may be used.

In this control, a continuous film formation test is performed for a predetermined time (e.g., 500 hours) with the magnet unit 3 in the cylindrical target 2 at a predetermined angle (e.g., tilted 5 degrees from the vertical (angle θ=5 degrees)). In this continuous film formation test, the Mg composition ratio of the formed alloy thin film is periodically analyzed. A technique such as X-ray fluorescence analysis can be used for the composition analysis. This makes it possible to know in advance how the Mg composition ratio changes over time in continuous film formation using an Mg-Ag alloy target.
Then, based on the results of this preliminary test, the change in the Mg composition ratio over time can be predicted in the actual continuous film formation, and the angle θ of the magnet unit 3 can be adjusted according to the predicted Mg composition ratio. For example, if the Mg composition ratio measured after 50 hours has elapsed in a preliminary test that started with an angle θ = 5 degrees and a target Mg composition ratio of 8.0 vol%, then in the actual continuous film formation, the angle θ of the magnet unit 3 can be adjusted to θ = 10 degrees after 50 hours have elapsed. This makes it possible to form a thin film with a constant Mg composition ratio in long-term continuous film formation.

Figure 17 shows the change over time in the Mg composition ratio of a thin film obtained in a long-term continuous manufacturing process. Graph A, which shows the solid line, shows the case where the angle θ of the magnet unit 3 is feedforward controlled based on the Mg composition ratio predicted from the results of a preliminary test, while graph B, which shows the dashed line, shows the case where the angle θ of the magnet unit 3 is fixed. As shown in Figure 17, when the angle θ of the magnet unit 3 is feedforward controlled, the Mg composition ratio can be maintained stably over a long period of time while the film is formed.

In the above example, a preliminary test was conducted to investigate the relationship between the elapsed time of continuous sputter deposition and the Mg composition ratio, and the relationship was then fed forward to the angle control of the magnet unit 3 during actual deposition. However, the relationship investigated in the preliminary test is not limited to this. For example, the relationship between the cumulative number of substrates on which films are deposited by continuous sputter deposition and the Mg composition ratio may be investigated, and the angle of the magnet unit 3 may be adjusted according to the number of substrates deposited during actual deposition.

Example 4
As an example of controlling the angle of the magnet unit 3 based on the composition ratio information, a control that feeds back the composition ratio information obtained from a measuring means installed in the film forming apparatus can be considered. The measuring means is provided in the inspection chamber 105 of the in-line type film forming apparatus 100 shown in FIG.

As shown in FIG. 18, the substrate 6 is provided with an inspection area 330 where a film is formed to evaluate the composition, in an area separate from the device area 340 where the cathode 65 is formed. The inspection device in the inspection chamber 105 measures the composition of the alloy thin film formed in the inspection area 330 of the substrate 6. This makes it possible to evaluate the Mg composition ratio of the alloy thin film formed in the film formation chamber 104 without affecting the thin film formed in the device area 340.

The alloy thin film deposited in the deposition chamber 104 undergoes composition analysis in the inspection chamber 105 located midway through the integrated vacuum production line, and the angle θ of the magnet unit 3 in the sputtering device 1 in the deposition chamber 104 is adjusted based on the composition analysis results. In this way, in the continuous thin film production process, the composition of the deposited alloy thin film can be monitored and the angle θ of the magnet unit 3 can be adjusted based on this information, allowing feedback control of the composition. This control reduces the time lag between deposition and adjustment of the angle θ of the magnet unit 3, and allows deposition to be performed with a constant composition ratio over long production periods.

Example 4 can also be applied to a cluster-type film formation apparatus 111 as shown in FIG. 3. In this case, the measurement result of the Mg composition ratio in the inspection chamber 105 is fed back to adjust the angle θ of the magnet unit 3 of the sputtering apparatus 1 in the film formation chamber 104 of the second cluster C2. If sputtering apparatuses with the same settings as the sputtering apparatus 1 are provided in other clusters, the measurement result of the Mg composition ratio in the inspection chamber 105 may also be fed back to control those sputtering apparatuses.

Example 5
A case will be described in which the angle control of the magnet unit 3 based on the composition ratio information is applied to a twin cathode sputtering apparatus 1Y shown in Fig. 9. Before a film formation process, the angles θL and θR of the first magnet unit 3L and the second magnet unit 3R shown in Fig. 11 or 12 are calculated based on the composition ratio information, and the first magnet unit 3L and the second magnet unit 3R are rotated. After adjusting the angles θL and θR of the first magnet unit 3L and the second magnet unit 3R, sputtering film formation is performed with the first magnet unit 3L and the second magnet unit 3R stationary at the adjusted angles.

The relationship between the angle θ of the magnet unit 3 described in FIG. 14 and the composition ratio of the formed alloy thin film does not depend on the sign of the angle θ in the sputtering apparatus 1 in FIG. 4, the sputtering apparatus 1X in FIG. 8, and the sputtering apparatus 1Y in FIG. 9, so the composition ratio of the alloy thin film does not change between the settings in FIG. 11 and FIG. 12.

As explained for sputtering apparatus 1, in the configuration of sputtering apparatus 1Y, the composition ratio of the alloy thin film can be controlled with high precision by adjusting the angles θL and θR of the first magnet unit 3L and second magnet unit 3R arranged within the first target 2L and second target 2R, which are cylindrical cathodes, based on the composition ratio information of the alloy thin film deposited on the substrate 6. In addition, by performing deposition multiple times with different angles θ of magnet unit 3, it is possible to deposit multi-layer films with different composition ratios.

According to the control of Examples 1 to 5 described above, in magnetron rotary sputtering deposition using an alloy target of two or more components, the angle θ of the magnet unit 3 arranged inside the target 2, which is a cylindrical cathode, is adjusted based on composition ratio information of the alloy thin film deposited on the substrate 6, so that the composition ratio of the alloy thin film can be controlled with high precision. As a result, even when performing sputtering deposition over a long period of time, an alloy thin film with little composition variation can be deposited, and the variation in device characteristics between substrates can be reduced. This increases production yields and enables devices to be manufactured stably over a long period of time.

In addition, in the magnetron rotary sputtering deposition using an alloy target of two or more components as described in Examples 1 to 5, the deposition method of adjusting the angle θ of the magnet unit 3 based on the composition ratio information of the alloy thin film deposited on the substrate 6, and the deposition method of depositing a multilayer film having different composition ratios (having a composition ratio gradient) in the thickness direction by magnetron sputtering using a rotary target made of an alloy material of two components by changing the angle θ of the magnet unit 3 of the rotating cathode unit 8 and performing deposition multiple times, can be applied to the in-line type deposition apparatus 100 shown in FIG. 2, the cluster type deposition apparatus 111 shown in FIG. 3, the substrate conveying type sputtering apparatus 1 shown in FIG. 4, the rotating cathode unit moving type sputtering apparatus 1X shown in FIG. 8, the twin cathode and rotating cathode unit moving type sputtering apparatus 1Y shown in FIG. 9, the twin cathode and substrate conveying type sputtering apparatus not shown, and the magnet unit swinging type sputtering apparatus shown in FIG. 13.

The above embodiment shows one example of the present invention, but the present invention is not limited to the configuration of the above embodiment, and may be modified appropriately within the scope of its technical concept. For example, it is not limited to a configuration in which the substrate moves relative to a rotating cathode unit fixed in a chamber, or a configuration in which the rotating cathode unit moves relative to a substrate fixed in a chamber, but may be, for example, a configuration in which the substrate and the rotating cathode unit are fixed in a chamber, and the number of targets constituting the rotating cathode unit is increased so that the sputtering area as a whole covers the entire area to be formed, a configuration in which the substrate oscillates in a horizontal plane relative to the rotating cathode unit fixed in a chamber, or a configuration in which the rotating cathode unit oscillates in a horizontal plane relative to a substrate fixed in a chamber. Although a twin cathode type sputtering device having two targets is illustrated in FIG. 9, the number of targets may be three or more.

1: sputtering device 2: target 3: magnet unit 6: substrate 35: rotating shaft 100: film forming device

Claims (20)

1. A cylindrical target made of an alloy of two or more components;
   a magnetic field generating means provided inside the target such that an angle around a rotation axis parallel to the central axis of the cylindrical shape can be changed, the magnetic field generating means generating a leakage magnetic field leaking from an outer peripheral surface of the target;
   having
   A film formation apparatus for forming an alloy thin film by sputtering on a film formation target disposed opposite the target while rotating the target,
   A film forming apparatus comprising: a control section for controlling an angle of said magnetic field generating means based on information on a composition ratio of said alloy thin film.
2. The film forming apparatus of claim 1, which controls the angle of the magnetic field generating means based on the composition ratio of the alloy constituting the target and the target value of the composition ratio of the alloy thin film to be formed on the film forming object.
3. The film forming apparatus according to claim 1, wherein when the film forming apparatus continuously forms films on a plurality of film forming objects, the angle of the magnetic field generating means is controlled based on information on the composition ratio of the alloy thin film of the film forming object on which a film has been formed in advance.
4. The film forming apparatus of claim 1 controls the angle of the magnetic field generating means based on information obtained experimentally in advance about the time change in the composition ratio of the alloy thin film formed when film formation is performed continuously on multiple film-forming objects.
5. a measuring means for measuring a composition ratio of the alloy thin film formed on the film-forming target,
   2. The film forming apparatus according to claim 1, wherein the angle of said magnetic field generating means is controlled based on information on the composition ratio measured by said measuring means.
6. The film forming apparatus according to any one of claims 1 to 5, which controls the angle of the magnetic field generating means based on a predetermined relationship between the angle of the magnetic field generating means and the composition ratio of the alloy thin film formed on the film forming target.
7. The film forming apparatus according to any one of claims 1 to 5, in which, when the film forming apparatus continuously forms films on a plurality of film forming objects, the angle of the magnetic field generating means is adjusted each time a film is formed on a predetermined number of the film forming objects.
8. The film forming apparatus according to any one of claims 1 to 5, in which, when the film forming apparatus continuously forms films on a plurality of film forming objects, the angle of the magnetic field generating means is adjusted every time a film is formed for a predetermined period of time.
9. The film forming apparatus according to any one of claims 1 to 5, in which the angle of the magnetic field generating means is controlled so that the difference between the composition ratio of the alloy thin film and the target composition ratio is 0.5% or less.
10. The deposition apparatus according to any one of claims 1 to 5, wherein the first component of the alloy constituting the target is Mg and the second component is Ag.
11. The deposition apparatus according to any one of claims 1 to 5, wherein the first component of the alloy constituting the target is Li, Na, Mg, K, Ca, Cs, or Yb, and the second component is Ag or Al.
12. The deposition apparatus according to any one of claims 1 to 5, wherein when a film is deposited on the deposition target using the target, the deposition amount distribution of the first component of the alloy constituting the target has a mountain-shaped shape that is wider and has a lower peak than the deposition amount distribution of the second component.
13. the magnetic field generating means is configured so that the composition ratio of the first component in the alloy thin film increases as the angle from a reference position increases,
    The film forming apparatus according to claim 10, wherein, based on the composition ratio of the alloy thin film, an angle of the magnetic field generating means is increased when the composition ratio of the first component is increased, and an angle of the magnetic field generating means is decreased when the composition ratio of the first component is decreased.
14. The deposition device according to any one of claims 1 to 5, wherein at least one of the voltage applied to the target and the deposition time is adjusted according to the angle of the magnetic field generating means.
15. The film forming apparatus according to any one of claims 1 to 5, which performs continuous film formation on a plurality of film forming objects.
16. The film forming apparatus according to any one of claims 1 to 5, wherein the alloy thin film constitutes the cathode of an organic electroluminescence element.
17. The deposition apparatus according to any one of claims 1 to 5, wherein the deposition apparatus is an in-line type deposition apparatus.
18. The deposition apparatus according to any one of claims 1 to 5, wherein the deposition apparatus is a cluster type deposition apparatus.
19. A cylindrical target made of an alloy of two or more components;
    a magnetic field generating means provided inside the target such that an angle around a rotation axis parallel to the central axis of the cylindrical shape can be changed, the magnetic field generating means generating a leakage magnetic field leaking from an outer peripheral surface of the target;
    A film forming method using a film forming apparatus having the following features:
    forming an alloy thin film by sputtering on a film-forming object disposed opposite the target while rotating the target;
    controlling an angle of the magnetic field generating means based on information on the composition ratio of the alloy thin film;
    A film forming method comprising the steps of:
20. A method for manufacturing an electronic device, comprising the steps of: Manufacturing an electronic device using the film forming method according to claim 19.

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