Sputtering apparatus and method for manufacturing electronic device

Abstract

To improve the quality of a deposition film by more effectively eliminating gas molecules from the inside of a chamber, especially the vicinity of a target, by using a getter material in a film deposition apparatus performing sputtering.SOLUTION: A sputtering apparatus includes a chamber accommodating a substrate, a target that is arranged facing a surface to be deposited of the substrate inside the chamber, and a non-evaporation getter pump arranged inside the chamber, the non-evaporation getter pump being arranged in a direction other than a direction where a material composing the target is discharged from the target in sputtering.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sputtering apparatus for forming a film on a substrate by sputtering, and a method for manufacturing an electronic device. [Background technology]

[0002] Sputtering is a method for forming thin films of metals, metal oxides, etc. on a substrate, a laminate formed on a substrate, or other target. In a sputtering device for forming films by sputtering, a sputtering gas is introduced into a vacuum chamber, and a negative voltage is applied to the target to generate a glow discharge, ionizing the sputtering gas and causing it to collide with the target surface at high speed. This causes the material that makes up the target to be ejected from the target surface as sputtered particles, which then adhere to and deposit on the target, forming a thin film. By introducing an inert gas such as Ar or a reactive gas such as O2 or N2 in addition to the inert gas as the sputtering gas, metal thin films and compound thin films such as oxides and nitrides can be formed.

[0003] One type of vacuum pump that can achieve a high vacuum in a vacuum chamber uses a non-evaporable getter (NEG) material. NEGs are made of Ti, Zr, V, Hf, Nb, Ta, or alloys of these materials. When activated by heating in a vacuum, they produce a highly reactive clean surface without evaporation, and exhibit pumping properties by adsorbing gas molecules such as H2, H2O, and O2.

[0004] Patent Document 1 discloses a sputtering apparatus in which an NEG pump is arranged in a vacuum chamber near a substrate, which is an object to be film-formed, and separated from the substrate and target by a shielding plate. Patent Document 2 discloses a sputtering apparatus in which an NEG pump is arranged in a vacuum chamber near a substrate, which is an object to be film-formed, on the opposite side of the substrate from the target. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-81952 [Patent Document 2] Japanese Patent Application Publication No. 8-203830 Summary of the Invention [Problem to be solved by the invention]

[0006] In a film deposition apparatus that performs sputtering, it is desired to use a getter material to more efficiently remove gas molecules from the inside of the chamber, particularly from the vicinity of the target, thereby improving the quality of the film deposition.

[0007] Furthermore, when fabricating devices such as organic light-emitting diodes (OLEDs) by forming metal electrodes by sputtering, good device characteristics may not be obtained, particularly when the substrate size is large. This is because, with conventional technology, it has been difficult to efficiently remove gas molecules from near the target in large sputtering devices that perform sputtering on large substrates. An object of the present invention is to provide a sputtering device that can efficiently remove gas molecules from near the target and obtain devices with good characteristics. [Means for solving the problem]

[0008] The present invention includes a chamber in which a substrate is accommodated; a target disposed inside the chamber so as to face a film-forming surface of the substrate; a non-evaporable getter pump provided inside the chamber; In a sputtering apparatus comprising: The non-evaporable getter pump is configured to pump a gas from the target in a direction other than the direction in which the material constituting the target is released from the target during sputtering. and within 30 cm of the target. The sputtering apparatus is characterized in that the The present invention also provides a substrate processing apparatus comprising: a chamber for accommodating a substrate; a target disposed inside the chamber so as to face a film-forming surface of the substrate; a non-evaporable getter pump provided inside the chamber; In a sputtering apparatus comprising: the non-evaporable getter pump is a sputtering apparatus that is disposed relative to the target in a direction other than a direction in which a material constituting the target is released from the target during sputtering, A plurality of the targets are provided, The sputtering apparatus is characterized in that the non-evaporable getter pump is disposed between a plurality of the targets.

[0009] The present invention also provides a substrate processing apparatus comprising: a chamber for accommodating a substrate; a cylindrical target disposed inside the chamber so as to face the film-forming surface of the substrate; a non-evaporable getter pump provided inside the chamber; a rotation means for rotating the target, In a virtual plane perpendicular to the rotation axis of the target, a virtual line segment connecting the rotation center of the target and the position of the non-evaporable getter pump is in polar coordinates with the rotation center of the target as the origin, and is an angle defined as a positive direction toward the film formation surface with respect to the position of a virtual plane that includes the rotation axis of the target and is parallel to the film formation surface of the substrate, and is included in the range of 45 degrees to 135 degrees. figure, The non-evaporable getter pump is located within 30 cm of the target. The sputtering apparatus is characterized by the above. The present invention also provides a substrate processing apparatus comprising: a chamber for accommodating a substrate; a cylindrical target disposed inside the chamber so as to face the film-forming surface of the substrate; a non-evaporable getter pump provided inside the chamber; a rotation means for rotating the target, a sputtering apparatus in which an imaginary line segment connecting the rotation center of the target and the position of the non-evaporable getter pump in an imaginary plane perpendicular to the rotation axis of the target is an angle defined as a polar coordinate with the rotation center of the target as the origin, the angle being positive in a direction toward the film formation surface with respect to the position of an imaginary plane that includes the rotation axis of the target and is parallel to the film formation surface of the substrate, and the angle is not within a range of 45 degrees to 135 degrees; A plurality of the targets are provided, The sputtering apparatus is characterized in that the non-evaporable getter pump is disposed between a plurality of the targets. [Effects of the Invention]

[0010] According to the present invention, in a film formation apparatus that performs sputtering, it is possible to more efficiently remove gas molecules from the vicinity of a target inside a chamber using a getter material. Also, by forming an electrode film using the sputtering apparatus of the present invention, it is possible to obtain an organic light-emitting diode with good characteristics. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a sputtering apparatus according to a first embodiment. [Figure 2] A diagram showing the general structure of an OLED. [Figure 3] FIG. 1 is a diagram illustrating the installation position of a NEG pump. [Figure 4] 10A to 10C are diagrams illustrating the effects of the first embodiment. [Figure 5] FIG. 5 is a schematic diagram showing the configuration of a sputtering apparatus according to a second embodiment. [Figure 6] FIG. 10 is a schematic diagram showing the configuration of a sputtering apparatus according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] The following describes in detail embodiments of the present invention. However, the following embodiments 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, processing 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 these alone. Although the embodiments describe multiple features, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numbers are used to designate identical or similar configurations, and redundant description will be omitted.

[0013] Example 1 The basic configuration of a sputtering apparatus 1 of Example 1 will be described with reference to Figure 1. Figure 1(A) is a diagram showing a schematic view of the internal configuration of the sputtering apparatus 1 as viewed from a direction parallel to the rotation axis of a cylindrical target 2 provided in the sputtering apparatus 1 (Y direction). Figure 1(B) is a diagram showing a schematic view of the internal configuration of the sputtering apparatus 1 as viewed from a direction parallel to the transport direction S of a substrate 6 transported within the sputtering apparatus 1 (X direction). The vertical direction is defined as the Z direction. Figure 1( 1C) is a diagram schematically showing the configuration of the magnet unit 3 provided inside the target 2. FIG.

[0014] The sputtering apparatus 1 according to the present embodiment is used to deposit and form a thin film on a substrate (including a substrate having a laminate formed thereon) in the manufacture of various electronic devices such as semiconductor devices, magnetic devices, and electronic components, as well as optical components. More specifically, the sputtering apparatus 1 is preferably used in the manufacture of electronic devices such as light-emitting elements, photoelectric conversion elements, and touch panels. In particular, the sputtering apparatus 1 according to the present embodiment is particularly preferably applicable to the manufacture of organic light-emitting elements such as OLEDs and organic photoelectric conversion elements such as organic thin-film solar cells. Note that the electronic device according to the present invention also includes a display device (e.g., an organic EL (Electro-Luminescence) display device) or 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. The present invention also includes a method for manufacturing an electronic device, which includes a step of forming a thin film on a substrate using the sputtering apparatus 1 according to the present embodiment or a sputtering apparatus obtained by modifying the sputtering apparatus 1 according to the present embodiment within the scope of the present invention.

[0015] FIG. 2 shows a typical layer structure of an OLED. OLEDs generally have a structure in which an anode, a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, an electron injection layer, and a cathode (upper electrode) are stacked on a substrate. The sputtering apparatus 1 according to this embodiment is suitable for use in forming a film of metal, metal oxide, or the like used for the electron injection layer or upper electrode on an organic film by sputtering. Furthermore, the sputtering apparatus 1 is not limited to forming a film on an organic film, and can form a film on a variety of surfaces as long as it is a combination of materials that can be formed into a film by sputtering, such as metal materials and oxide materials.

[0016] As shown in FIG. 1(A), the sputtering apparatus 1 has a chamber 10 in which a substrate 6, which is a film formation 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 deposition-up with the film formation surface of the substrate 6 facing vertically downward. However, the present invention is not limited to this, and a configuration in which the target 2 is placed vertically above the substrate 6, and film formation is performed by deposition-down with the film formation surface of the substrate 6 facing vertically upward, may also be used. Alternatively, a configuration in which the substrate 6 is set up vertically, and film formation is performed with the film formation surface of the substrate 6 parallel to the vertical direction may also be used.

[0017] The rotating cathode unit 8 has a cylindrical target 2 and a magnet unit 3 as a magnetic field generating unit that is disposed in the hollow portion inside the target 2 and generates a magnetic field on the outer periphery of the target 2. A backing tube 2a is provided inside the target 2.

[0018] The target 2 is composed 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, we will explain an example in which a cathode (top electrode) made of Ag or an Ag alloy (e.g., an Ag-Mg alloy) is formed by sputtering on a substrate on which an OLED anode and an organic light-emitting layer have already been formed. Therefore, the film-forming material constituting the target 2 contains Ag or an Ag alloy. The sputtering apparatus of the present invention is not limited to the formation of an upper electrode made of Ag or an Ag alloy, and the film-forming material of the target 2 may be a metal such as Cu, Al, Ti, Mo, Cr, Ag, Au, or Ni, or an alloy or compound containing these metal elements, depending on the purpose. Transparent conductive oxides such as ITO, IZO, IWO, AZO, GZO, and IGZO may also be used as the film-forming material of the target 2.

[0019] Inside the layer of the target 2 where the film forming material is formed, a layer of a backing tube 2a made of a different material is formed. A power supply 13 is connected to the backing tube 2a, and it functions as a cathode to which a negative voltage is applied from the power supply 13. Note that the voltage may be applied directly to the target 2, in which case the backing tube 2a may not be provided. The power supply 13 may be a DC power supply, an AC power supply, or a high frequency power supply depending on the material of the target 2. The chamber 10 is grounded. The target 2 is a cylindrical target, but the term "cylindrical" as used here does not mean only a mathematically strict cylindrical shape, but also includes targets whose generatrix is ​​a curved line rather than a straight 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 any cylindrical target that can be rotated around a central axis.

[0020] The magnet unit 3 generates a magnetic field on the surface of the target 2 facing the substrate 6. As shown in FIG. 1(C), the magnet unit 3 includes a central magnet 31 extending parallel to the rotation axis of the target 2, a peripheral magnet 32 ​​surrounding the central magnet 31 and having 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 linear portions 32a and 32b extending parallel to the central magnet 31 and turning portions 32c and 32d connecting both ends of the linear portions 32a and 32b. The magnetic field generated by the magnet unit 3 has magnetic field lines that loop back from the magnetic pole of the central magnet 31 to the linear 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, concentrating plasma near the surface of the target 2 and improving sputtering efficiency. The magnetic field of this magnet unit 3 generates high density plasma, and the region where sputtered particles are generated intensively is defined as a sputtering region A.

[0021] The rotating cathode unit 8 is fixed to the chamber 10. The target 2 is supported so as to be rotatable around the central axis of the cylinder. Specifically, 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 a driving force from a target driver 11, which is a rotational driver, to the target 2. The target driver 11 has a drive source such as a motor, and drives the target 2 to rotate via the power transmission mechanism. The magnet unit 3 inside is supported in a state where it does not rotate. In other words, the target driver 11 of the sputtering apparatus 1 has a drive mechanism that rotates the target 2 while keeping the magnet unit 3 stationary.

[0022] The substrate 6 is loaded through one gate valve 17 provided on a side wall of the chamber 10. A film is formed on the substrate 6 by sputtering while the substrate 6 is transported horizontally (in the direction indicated by the arrow S) within the chamber 10 by a transport member 120. After a film is formed on the entire film-forming 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.

[0023] Chamber 10 is connected to gas introduction means 16 and exhaust means 15, and is configured so that 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. Furthermore, the interior of chamber 10 is exhausted by exhaust means 15, such as a vacuum pump, through exhaust port 5. In this way, the pressure inside chamber 10 is adjusted to a predetermined level.

[0024] 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 to the inlet 41, and various vacuum valves, mass flow controllers, etc. provided in the piping system. 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 ceiling wall. Alternatively, the piping may extend into the chamber 10, and the inlet may open into the chamber 10. Alternatively, multiple inlets 41 may be provided and arranged along the direction of the rotation axis of the target 2.

[0025] The exhaust means 15 includes a vacuum pump and a piping system connecting the vacuum pump to the exhaust port 54. 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. 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 ceiling wall. Alternatively, the piping may extend into the chamber 10, and the exhaust port 5 may open into the chamber 10.

[0026] A non-evaporable getter pump 7 (hereinafter referred to as the NEG pump) is provided near the rotating cathode unit 8. The NEG pump 7 is composed of a stainless steel structure containing a sintered NEG material capable of adsorbing chemically active species such as H2, HO, O2, N2, CO, and CO2, and has a built-in electric resistance heater for activating the NEG material. The NEG pump 7 is arranged along the rotation axis direction (Y direction) of the target 2. The length of the NEG pump 7 in the Y direction is approximately the same as the length of the target 2 in the Y direction, as shown in Figure 1(B). The NEG material (non-evaporable getter material) is Ti, Zr, V, Al, Ta, W, Mo, Hf, Nb, Fe, or an alloy containing these as its main components. It is activated by heating it to approximately 500°C using a heater and removes gas molecules in the chamber 10 by chemical adsorption. The NEG pump 7 has virtually no effect on chemically inactive species such as Ar and Xe used as sputtering gases. In light of the above, unless otherwise specified, the term "gas molecules" in this specification refers to chemically active molecules such as H2, HO, O2, N2, CO, and CO2, excluding inactive species such as Ar. The control unit 14 controls the activation state of the NEG pump 7 by controlling the power supply to the heater of the NEG pump 7, and controls the exhaust by the NEG pump 7. Note that the configuration, heating method, and heating temperature of the NEG pump 7 are merely examples and are not limited to the above examples. For example, the NEG material may be in the form of a powder or compressed into a pill, and the length of the NEG pump 7 in the Y direction may be shorter or longer than the length of the target 2 in the Y direction. Furthermore, the NEG pump may be divided and arranged at multiple positions.

[0027] FIG. 3 is a conceptual diagram illustrating the positional relationship between the NEG pump 7 and the target 2. FIG. 3(A) shows the positional relationship between the NEG pump 7 and the target 2 when a cylindrical target 2 is used to perform sputtering deposition on the vertically lower surface of a substrate 6 placed above the target 2 in a deposition-up manner. The NEG pump 7 is placed near the target 2, facing in a direction other than the direction in which ejected material (sputtered particles) is emitted from the target 2 during sputtering. As shown in FIG. 3(A), sputtering gas ions (e.g., Ar + When the target 2 collides with the surface of the target 2, atoms and molecules of the film-forming material that constitutes the target 2 are released from the target 2 as sputtered particles.

[0028] The location and direction of these emissions (sputtered particles) from the surface of the target 2 during sputtering can be determined by the magnetic field generated near the surface of the target 2 by the magnet unit 3. Figure 3(C) shows a perspective view of a cylindrical target and the location where sputtered particles are emitted due to the generation of high-density plasma. As shown in Figure 3(C), a high-density plasma region is formed on the cylindrical surface in a track-like shape along the angles α and β. The angles α and β are defined in polar coordinates with the rotation center of the target 2 as the origin, with the positive angle defined as the direction toward the film-forming surface of the substrate 6, relative to the position of an imaginary plane that includes the rotation axis of the target 2 and is parallel to the film-forming surface of the substrate 6. In Figure 3(A), the angles α and β are approximately defined by the positions of line segments D2 and D3 that pass through the rotation center O of the target 2 and the position between the central magnet 31 and the peripheral magnet 32. Many sputtered particles are emitted from the outer periphery of the target 2 along the angles α and β. Many sputtered particles are also emitted along the angles α and β. In this specification, the range defined by the angles α and β is called the sputtering region.

[0029] The position at which the NEG pump 7 is disposed is a position within an imaginary plane perpendicular to the rotation axis of the target 2 such that an imaginary line segment (for example, line segments L1, L2, and L3 in FIG. 3A) connecting the rotation center O of the target 2 and the position of the NEG pump 7 does not intersect with an arc C corresponding to the range of angles α to β. For example, when arc C faces the substrate 6 as in this embodiment, the NEG pump 7 can be disposed on the opposite side of arc C (the back side of the target 2). Such an arrangement of the NEG pump 7 makes use of the characteristics of a rotary cathode, in that the shape of the target 2 is cylindrical and is supported at its end, and is a preferred arrangement from the viewpoint of being able to be installed in close proximity.

[0030] Arc C corresponds to a predetermined area on the surface of target 2 facing the film formation target surface of substrate 6, within an imaginary plane perpendicular to the rotation axis of target 2. The predetermined area corresponding to arc C can be set, for example, as a range up to angles α and β determined based on the magnetic flux distribution of the magnetic field formed by magnet unit 3. Alternatively, it can be an area on the surface of target 2 where the magnetic field strength is equal to or greater than a certain value. Alternatively, it may be determined based on the arrangement and structure of the magnets of magnet unit 3, the position where sputtered particles are generated intensively, or phenomena generally, statistically, empirically, or experimentally observed as the direction of emission from the surface of target 2 during sputtering.

[0031] For example, depending on the design of the magnet unit, α can be set in the range of 45 degrees to 80 degrees (β is set in the range of 100 degrees to 135 degrees). In this embodiment 1, α is set to 60 degrees and β is set to 120 degrees. Alternatively, α may be set to 45 degrees and β to 135 degrees. In this case, the imaginary line segment connecting the rotation center of the target 2 and the position of the NEG pump 7 in an imaginary plane perpendicular to the rotation axis of the target 2 is not included in the range of angles from 45 degrees to 135 degrees in the polar coordinates defined above. Furthermore, the position of the NEG pump 7 is set to, for example, the position of the center of gravity of the NEG pump 7, but is not limited to this.

[0032] Here, the α and β directions are configured to be symmetrical with respect to the vertical direction, but they do not necessarily have to be symmetrical. That is, the sputtering region A and the arc C may be arranged in a direction tilted from the vertically upward direction. For example, an example in which the sputtering region faces the horizontal direction is when α is 330 degrees and β is 30 degrees. An example in which the sputtering region faces an oblique direction is when α is 15 degrees and β is 75 degrees.

[0033] In FIGS. 1(A) and 1(B), the NEG pump 7 is depicted as being disposed on the bottom surface of the chamber 10, but it may be disposed at any position that satisfies the above-described positional relationship. If necessary, a support for supporting the NEG pump 7 may be provided on the bottom surface of the chamber 10, and the NEG pump 7 may be disposed on the support. The distance between the NEG pump 7 and the target 2 is determined appropriately within a range that satisfies the above-described positional relationship, but it is preferable to dispose the NEG pump 7 within 30 cm from the surface of the target 2. Disposing the NEG pump close to the target allows gas molecules released from the target to be adsorbed efficiently in a short time, thereby reducing the molecular weight adsorbed on the target surface. Furthermore, disposing the NEG pump 7 within 20 cm from the surface of the target 2 is preferable because it allows the device to be made more compact.

[0034] FIG. 3(B) shows the positional relationship between the NEG pump 7 and the target 2 when a cylindrical target 2 is used to perform sputtering deposition on the vertically upper surface of a substrate 6 placed below the target 2 in a deposition-down manner. In the deposition-down manner, angles α and β can be determined using the same concept as in the deposition-up manner described above. In the deposition-down manner, the positive direction of the polar coordinate angle is opposite to that in the deposition-up manner shown in FIG. 3(A), as shown in FIG. 3(B). As in the deposition-up manner, the ranges of angles α and β can be set such that α is in the range of 45 to 80 degrees and β is in the range of 100 to 135 degrees. For example, α can be set to 60 degrees and β can be set to 120 degrees. It can be set to 0 degrees.

[0035] Although Example 1 illustrates an example in which the present invention is applied to a sputtering apparatus that performs sputtering using a cylindrical target 2, the present invention can also be applied to a sputtering apparatus that performs sputtering using a flat target. Figure 3(D) shows the positional relationship between the NEG pump 7 and the target 2X when a flat target 2X is used to perform sputtering film formation by deposition-up on the surface vertically below a substrate 6 placed above the target 2X. In this case, too, the NEG pump 7 is positioned relative to the target 2X in a direction other than the direction in which materials emitted from the target 2X are released during sputtering. For example, the NEG pump 7 is positioned so that the surface of the NEG pump 7 closest to the substrate 6 is located on the opposite side of the substrate 6 from the imaginary plane P that includes the surface of the target 2X facing the substrate 6.

[0036] When forming a film by sputtering in the sputtering apparatus 1 of Example 1, the control unit 14 controls the target driver 11 to drive and rotate the target 2 in the direction of arrow R, and also controls the power supply 13 to apply a negative voltage to the target 2. The magnet unit 3 does not rotate, and a leakage magnetic field is always generated on the surface of the target 2 facing the substrate 6. 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. Positive inert gas ions in the plasma collide with the surface of the target 2, and 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 deposit on the surface of the substrate 6 on which the film is to be formed.

[0037] At this time, impurities such as oxygen and hydrogen contained in the target and gas molecules adsorbed on the target surface are also released from the surface of the target 2. That is, in addition to the material constituting the target being released as sputtered particles, a considerable amount of gas molecules are also released. In this embodiment, these gas molecules are efficiently exhausted (adsorbed) by the NEG pump arranged near the target.

[0038] In this embodiment, the rotating cathode unit 8 is fixed relative to the chamber 10, and therefore the sputtering region A does not move relative to the chamber 10. Furthermore, the magnet unit 3 does not rotate together with the target 2 and does not move relative to the chamber 10, and therefore the opposing angle between the sputtering region A and the film-forming surface of the substrate 6 is constant during the film formation process. Here, the opposing angle between the sputtering region 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 an arc corresponding to the sputtering region A on the cylindrical surface of the target 2 and a virtual plane that includes the film-forming surface of the substrate 6, within a virtual plane perpendicular to the rotation axis of the target 2.

[0039] As the substrate 6 is moved horizontally by the transport member 120, the region of the film formation target surface of the substrate 6 that faces the sputtering region 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, a film is formed uniformly by sputtering over the entire surface of the substrate.

[0040] The area on the surface of the target 2 from which sputter particles are emitted moves in the circumferential direction as the target 2 rotates. Therefore, when focusing on a local area on the surface of the target 2, it is intermittently sputtered at a period determined by the rotation speed of the target 2. In a sputtering device in which the surface of the target 2 is intermittently sputtered in this way, arranging the NEG pump 7 near the target 2 is effective in reducing gas molecules near the target 2. During the time period when sputtering is not occurring (the NN period in FIG. 4), the NEG pump 7 can adsorb (exhaust) the gas molecules emitted during sputtering (the SP period in FIG. 4), thereby reducing the gas molecules near the surface of the target 2. This method will be explained with reference to FIG. 4, taking the case where a rotary cathode is used as an example.

[0041] FIG. 4(A) is a conceptual diagram showing the change over time in the amount of sputtered particles emitted from a local region on the surface of the target 2 when a film is formed by sputtering in the sputtering apparatus 1 of Example 1. The local region on the surface of the target 2 is a partial region corresponding to a specific angular direction on the outer circumferential surface of the cylindrical target 2. The target 2 rotates in the direction of arrow R during sputtering. However, since the position of the sputtering region A does not change, the local region on the surface of the target 2 is intermittently sputtered at time intervals determined by the rotation period, as shown in FIG. 4(A). The sputtering period is indicated by SP, and the non-sputtering period is indicated by NN. When the surface of the target 2 is sputtered, not only are sputtered particles emitted, but also impurities such as oxygen and hydrogen contained in the target 2 and gas molecules adsorbed on the surface of the target 2. That is, in addition to the material constituting the target 2 being emitted as sputtered particles, a considerable amount of gas molecules are also emitted. These gas molecules and their radicals and ions remain near the surface of the sputtered target 2.

[0042] FIG. 4(B) is a conceptual diagram showing the temporal change in the partial pressure of gases such as oxygen and water near a localized region on the surface of the target 2. Graph G1 shows the change in gas partial pressure in the sputtering apparatus 1 of Example 1, and graph G2 shows the change in gas partial pressure without the NEG pump. In graph G2, because the gas molecules near the localized region generated by sputtering cannot be exhausted in a short time, a considerable amount of gas partial pressure is maintained near the target surface during time period NN, resulting in adsorption of oxygen and water molecules to the target surface. Next, when the localized region is sputtered (time period SP), these adsorbed molecules are released, causing an increase in the gas partial pressure. As a result, the gas molecules are incorporated into the film being formed as impurities. Furthermore, during time period NN, the target surface is oxidized by the gas molecules, reducing the cleanliness of the target surface. As a result, oxygen on the target surface is released as negative ions, which irradiate the substrate and damage the organic film underlying the substrate. Due to these phenomena, when applied to the formation of the upper electrode of an organic EL device, good device characteristics may not be obtained.

[0043] On the other hand, when a film is formed by sputtering using the sputtering apparatus 1 of Example 1, the NEG pump 7 disposed near the target 2 adsorbs gas molecules near the target 2, thereby reducing the gas partial pressure near the localized region, as shown in graph G1. In particular, the gas molecules released near the target 2 during time period SP are quickly adsorbed by the NEG pump 7, thereby reducing the amount of molecules adsorbed on the surface of the target 2 during time period NN when sputtering is not occurring. Next, when the localized region is sputtered (time period SP), the amount of gas molecules released from the surface of the target 2 is significantly reduced. As a result, the gas partial pressure near the target 2 during sputtering can be maintained low. Reducing the gas molecules near the target 2 reduces the amount of impurities mixed into the film being formed. Furthermore, oxidation of the surface of the target 2 can be suppressed, thereby maintaining cleanliness. Suppressing oxidation of the surface of the target 2 can suppress damage to substrate underlayers, such as organic films, caused by the generation of negative oxygen ions. As a result, when applied to the formation of upper electrodes for organic EL devices, devices with excellent characteristics can be achieved.

[0044] The NEG pump 7 is arranged in a direction other than the direction in which substances emitted from the target 2 are emitted during sputtering. Since the NEG pump 7 is not covered with the film-forming material that is knocked out from the surface of the target 2 by sputtering, the NEG pump 7 can be used for a long period of time. In addition, since the NEG pump 7 is arranged in a direction other than the sputtering region of the target 2 and in the vicinity of the target 2, gas molecules near the surface of the target 2 can be reliably pumped. In particular, by arranging the NEG pump 7 on the side of the rotary cathode opposite the sputtering region facing the substrate 6 (the back side of the cylinder), it is possible to achieve both the requirement of preventing adhesion of emitted materials (sputtered particles) and the requirement of being located near the cathode. Furthermore, taking into account the characteristic that the surface of the target 2 is intermittently sputtered as the rotary cathode rotates, arranging the NEG pump 7 in an appropriate position can reduce the amount of gas molecules adsorbed to the target 2 during the NN period. This reduces the release of gas molecules during the SP period and realizes a reduction in the partial pressure of gases such as oxygen and water on the surface of the target 2 and its vicinity during sputtering. Furthermore, since the sputtering apparatus 1 does not have a member between the target 2 and the NEG pump 7 that shields the NEG pump 7 from the target 2, gas molecules can be more reliably adsorbed. Furthermore, because the NEG pump 7 does not adsorb inert gas molecules such as Ar, the installation of the NEG pump 7 does not affect sputtering.

[0045] As a result, when an electrode film for an OLED element is formed using the sputtering apparatus 1 of Example 1, a device with good element characteristics can be realized. Although film formation apparatuses for large substrates are prone to being affected by degassing in the chamber, the method of this example can also be applied to film formation on large substrates of G4 (680 mm × 880 mm) or larger. When forming a film made of Ag or an Ag alloy such as MgAg as the upper electrode (cathode) of an OLED, the film may be affected by minute pressure fluctuations in the chamber, but the method of this example allows for stable film formation. Note that elements fabricated using the sputtering apparatus of the present invention are not limited to OLEDs. Furthermore, the film layer formed when fabricating an OLED is not limited to the upper electrode.

[0046] <Example 2> A sputtering apparatus 1X according to a second embodiment of the present invention will be described with reference to FIG. 5. Components common to those in the first embodiment are designated by common reference numerals, and detailed description thereof will be omitted. FIG. 5(A) is a diagram schematically 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 (referred to as the Y direction). FIG. 5(B) is a diagram schematically showing the internal configuration of the sputtering apparatus 1X as viewed from a direction parallel to the movement direction T of a rotating cathode unit 8X moving within the sputtering apparatus 1X (referred to as the X direction).

[0047] In the sputtering apparatus 1 of Example 1, the rotary cathode unit 8 does not move relative to the chamber 10, and the substrate 6 moves relative to the chamber 10, thereby forming a film on the film formation target surface of the substrate 6 sequentially from the end downstream in the transport direction of the substrate 6. In the sputtering apparatus 1X of Example 2, the rotary cathode unit 8X moves relative to the chamber 10, and the substrate 6 does not move relative to the chamber 10, and film formation is performed on the film formation target surface of the substrate 6 sequentially from the end upstream in the movement direction of the rotary cathode unit 8X. Furthermore, while the rotary cathode unit 8 of the sputtering apparatus 1 of Example 1 was composed of one set of cylindrical targets 2 and a magnet unit 3, the rotary cathode unit 8X of the sputtering apparatus 1X of Example 2 is composed of two sets of cylindrical targets 2L, 2R and magnet units 3L, 3R. The configuration of each set of targets and magnet units is the same as in Example 1, but the rotation directions caused by the target drive device 11 are opposite to each other. The target 2L rotates in the direction of the arrow L, and the target 2R rotates in the direction of the arrow R, which is opposite to the direction of the arrow L.

[0048] The rotating cathode unit 8X has a movable stage 230, and a support block 210 and end block 220 that rotatably support the targets 2L and 2R. On the movable stage 230, the targets 2L and 2R are arranged side by side in the moving direction T (parallel to the X direction) of the rotating cathode unit 8X. The NEG pump 7 is arranged between the targets 2L and 2R on the movable stage 230. Therefore, the NEG pump 7 moves together with the targets 2L and 2R. The movable stage 230 is provided with a partition member 260 that is arranged to surround the targets 2L and 2R. Note that in FIG. 5(B), the partition member 260 is omitted to avoid complication. Partition section The member 260 is open in the direction in which the substrate 6 is placed (vertically upward), so as not to prevent the sputtering areas AR and AL of the targets 2L and 2R from facing the surface of the substrate 6 on which a film is to be formed.

[0049] The movable stage 230 is supported via conveyance guides 240, such as linear bearings, so as to be freely movable in the horizontal direction along a pair of guide rails 250. The guide rails 250 are provided parallel to the X direction. The movable stage 230 is linearly driven in the X direction by a linear drive device 12. The linear drive device 12 may be any of a variety of known linear motion mechanisms, such as a linear motor or a screw feed mechanism using a ball screw or the like that converts the rotational motion of a rotary motor into linear motion. Therefore, the rotating cathode unit 8X moves in the X direction within the XY plane, and the targets 2L and 2R move in the X direction within the XY plane while rotating around a rotation axis parallel to the Y direction.

[0050] When the substrate 6 is loaded into the chamber 10, it is held by a 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 rotating cathode unit 8X moves horizontally (in the direction indicated by the arrow T) while the film is formed by sputtering. After the film is formed over 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.

[0051] When forming a film by sputtering in the sputtering apparatus 1X of Example 2, the control unit 14 controls the target drive device 11 to rotate the targets 2L and 2R in the directions of the arrows L and R, and also controls the power supply 13 to apply a negative voltage to the targets 2L and 2R. The magnet unit 3 does not rotate, and always generates a leakage magnetic field on the surface side of the targets 2L and 2R that faces the substrate 6. The manner of film formation by sputtering is the same as in Example 1.

[0052] The rotating cathode unit 8X is moved in the direction of arrow T relative to the chamber 10 by the linear drive device 12, and therefore the sputtering regions AR and AL move in the direction of arrow T relative to the chamber 10. Furthermore, since the magnet units 3R and 3L do not rotate together with the targets 2R and 2L, the opposing angle between the sputtering region 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.

[0053] As the rotating cathode unit 8X moves horizontally by the linear drive device, the sputtering areas AL and AR of the targets 2L and 2R move along the film-forming surface of the substrate 6 relative to the chamber 10 along with the movement of the rotating cathode unit 8X. As a result, film is formed on the film-forming surface of the substrate 6 sequentially from the upstream end to the downstream end in the movement direction T of the rotating cathode unit 8X as the rotating cathode unit 8X moves.

[0054] When a film is formed by sputtering in the sputtering apparatus 1X of Example 2, gas molecules near the targets 2L and 2R are adsorbed by the NEG pump 7 disposed between the targets 2L and 2R and in the vicinity of the targets 2L and 2R. Therefore, similar to Example 1, the gas molecules near the surfaces of the targets 2L and 2R are significantly reduced. Therefore, a high-purity film can be formed without causing significant damage to the underlying organic material on the film-forming surface of the substrate 6, and an OLED with good device characteristics can be fabricated.

[0055] In the apparatus of this embodiment, the NEG pump 7 is disposed between the two targets 2L and 2R so that the NEG pump can exert an adsorption effect on gas molecules emitted from both of the two targets 2L and 2R. Despite the small number of NEG pumps, this is an apparatus configuration that effectively exerts an exhaust effect on multiple targets.

[0056] The outer diameter of the cylindrical targets 2L and 2R is 140 mm. The distance between the centers of the targets 2L and 2R is 300 mm. The distance between the center of the targets 2L and 2R and the NEG pump 7 is 250 mm. By arranging them in this way, it is possible to arrange the NEG pump 7 close to the two targets 2L and 2R. Furthermore, the close arrangement makes it possible to make the device smaller and lighter.

[0057] In the apparatus of this embodiment, the targets 2L and 2R and the NEG pump 7 move together within the chamber. With this configuration, the NEG pump always functions to pump gas molecules near the targets, even as the targets move. This allows the partial pressure of gases such as oxygen near the target surface to be maintained low, even as the targets move within the chamber.

[0058] Example 3 A sputtering apparatus 1Y according to a third embodiment of the present invention will be described with reference to Fig. 6. Components common to those in the first and second embodiments are given the same reference numerals, and detailed descriptions thereof will be omitted. Fig. 6 is a diagram schematically illustrating the internal configuration of the sputtering apparatus 1Y as viewed from a direction parallel to the rotation axes of cylindrical targets 2L and 2R provided in the sputtering apparatus 1Y (referred to as the Y direction).

[0059] In the sputtering apparatus 1Y of Example 3, the rotating cathode unit 8Y does not move relative to the chamber 10, and the substrate 6 is held by a holder 6a and does not move relative to the chamber 10 during the film formation process. Similar to the rotating cathode unit 8X of the sputtering apparatus 1X of Example 2, the rotating cathode unit 8Y is composed of two sets of cylindrical targets 2L, 2R and magnet units 3L, 3R, and both are rotated by a target drive device 11.

[0060] In Examples 1 and 2, the magnet units 3, 3L, and 3R were supported without rotating and therefore without moving relative to the chamber 10. However, in Example 3, the magnet units 3L and 3R are supported so as to oscillate and therefore move relative to the chamber 10. Therefore, the sputtering region, where plasma is generated by the magnetic field generated by the magnet units 3L and 3R and sputtered particles are generated, oscillates between sputtering region A and sputtering region B in accordance with the oscillation of the magnet units 3L and 3R. In other words, the opposing angle between the sputtering region and the film formation target surface of the substrate 6 changes in accordance with the oscillation of the magnet units 3L and 3R during the film formation process. The angular range over which the magnet units 3L and 3R oscillate is determined between sputtering region A and sputtering region B so that a uniform film is formed over the range from the end on the +X direction side to the end on the −X direction side of the film formation target surface of the substrate 6, which is held stationary. Targets 2L and 2R are arranged side by side in the X direction, and NEG pumps 7L and 7R are provided separately near targets 2L and 2R, respectively. The NEG pumps are placed directly below the targets so that sputtered particles emitted between sputtering region A and sputtering region B do not adhere to the NEG pumps.

[0061] When the substrate 6 is carried into the chamber 10, it is held by a holder 6a vertically above the rotating cathode unit 8Y. During the film formation process, the substrate 6 does not move relative to the chamber 10, and film formation is performed by sputtering while the magnet units 3L and 3R of the rotating cathode unit 8Y oscillate as shown by arrow W and the target 2 rotates as shown by arrows R and L. After film formation has been performed on the entire film formation target surface of the substrate 6, the substrate 6 is carried out through a gate valve 18 provided on the other side wall of the chamber 10.

[0062] When forming a film by sputtering in the sputtering apparatus 1Y of Example 3, the control unit 14 controls the target drive device 11 to rotate the targets 2L and 2R, drives the magnet units 3L and 3R to oscillate, and controls the power supply 13 to apply a negative voltage to the targets 2L and 2R. The magnet unit 3 oscillates, generating a leakage magnetic field on the surface side of the targets 2L and 2R facing the substrate 6. The manner of film formation by sputtering is the same as in Example 1. It seems that

[0063] The rotating cathode unit 8Y and the substrate 6 do not move relative to the chamber 10 during the film formation process. Because the magnet units 3R and 3L oscillate, the opposing angle between the sputtering region and the film formation target surface of the substrate 6 changes during the film formation process. As a result, film formation is performed on the film formation target surface of the substrate 6 sequentially between the upstream end and downstream end in the X direction as the magnet units 3R and 3L oscillate.

[0064] When a film is formed by sputtering in the sputtering apparatus 1Y of Example 3, gas molecules near the targets 2L and 2R are adsorbed by the NEG pumps 7L and 7R disposed near the targets 2L and 2R, respectively. Therefore, similar to Examples 1 and 2, the gas molecules near the surfaces of the targets 2L and 2R are significantly reduced. Therefore, a high-purity film can be formed without causing significant damage to the underlying organic material on the film-forming surface of the substrate 6, and an OLED with good device characteristics can be fabricated.

[0065] In this example, the magnet unit of the rotary cathode is oscillated to oscillate the direction of sputter particle emission. However, by placing the NEG pump on the side of the rotary cathode that does not face the substrate (back side), the NEG pump can be placed in a position where sputter particles do not adhere, even though it is close to the cathode. This eliminates the need to transport the substrate or target during film formation, and allows for a compact device configuration while reducing gas molecules near the target.

[0066] The above-described embodiments illustrate examples of the present invention, but the present invention is not limited to the configurations of the above-described embodiments and may be modified appropriately within the scope of the technical concept thereof. For example, Example 1 illustrates a configuration in which the substrate moves relative to a rotating cathode unit fixed in a chamber, Example 2 illustrates a configuration in which the rotating cathode unit moves relative to a substrate fixed in a chamber, and Example 3 illustrates a configuration in which the substrate and rotating cathode unit are fixed in a chamber and the sputtering region is oscillated to cover the entire film formation target region. However, the configuration of the sputtering apparatus is not limited to these. For example, a configuration in which the substrate and rotating cathode unit are fixed in a chamber and the number of targets constituting the rotating cathode unit is increased so that the sputtering region as a whole covers the entire film formation target region, a configuration in which the substrate oscillates in a horizontal plane relative to a 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 may also be used. While Examples 2 and 3 illustrate sputtering apparatuses equipped with a rotating cathode unit having two targets, the number of targets may be one or three or more. [Explanation of symbols]

[0067] 1: sputtering device, 2: target, 6: substrate, 7: non-evaporable getter pump, 10: chamber

Claims

1. a chamber in which the substrate is housed; a target disposed inside the chamber so as to face a film-forming surface of the substrate; a non-evaporable getter pump provided inside the chamber; In a sputtering apparatus comprising: A sputtering apparatus characterized in that the non-evaporable getter pump is arranged at a distance of 30 cm or less from the target in a direction other than the direction in which the material constituting the target is released from the target during sputtering.

2. a chamber in which the substrate is housed; a target disposed inside the chamber so as to face a film-forming surface of the substrate; a non-evaporable getter pump provided inside the chamber; In a sputtering apparatus comprising: the non-evaporable getter pump is a sputtering apparatus that is disposed relative to the target in a direction other than a direction in which a material constituting the target is released from the target during sputtering, A plurality of the targets are provided, A sputtering apparatus characterized in that the non-evaporable getter pump is disposed between a plurality of the targets.

3. the target is cylindrical; 3. The sputtering apparatus according to claim 1, further comprising a rotating means for rotating the target.

4. In a virtual plane perpendicular to the rotation axis of the target, a virtual line segment connecting the rotation center of the target and the position of the non-evaporable getter pump is formed on the target surface facing the film formation surface of the substrate.

4. The sputtering apparatus according to claim 3, wherein the arc does not intersect with an arc corresponding to an area on the surface of the nozzle where sputter particles are generated intensively during sputtering.

5. The sputtering apparatus of claim 3, wherein a virtual line segment connecting the rotation center of the target and the position of the non-evaporable getter pump in a virtual plane perpendicular to the rotation axis of the target is an angle defined in polar coordinates with the rotation center of the target as the origin, the angle being positive in the direction toward the film formation surface based on the position of a virtual plane that includes the rotation axis of the target and is parallel to the film formation surface of the substrate, and the angle is not within the range of 45 degrees to 135 degrees.

6. a magnetic field generating unit that is disposed in a hollow portion inside the target and generates a magnetic field around the outer periphery of the target; 5. The sputtering apparatus according to claim 4, wherein the arc is determined based on a position in the vicinity of the surface of the target where plasma is generated during sputtering by the magnetic field generated by the magnetic field generating unit.

7. A plurality of the targets are provided, 2. The sputtering apparatus according to claim 1, wherein the non-evaporable getter pump is disposed between a plurality of the targets.

8. a moving means for moving the target relative to the chamber; 3. The sputtering apparatus according to claim 1, wherein the non-evaporable getter pump moves together with the target.

9. 9. The sputtering apparatus according to claim 1, wherein the non-evaporable getter pump is disposed at a distance of 20 cm or less from the target.

10. 10. The sputtering apparatus according to claim 1, wherein the target contains Ag or an Ag alloy.

11. The sputtering apparatus according to any one of claims 1 to 10, wherein the sputtering apparatus is used to deposit an upper electrode of an organic light-emitting diode.

12. 12. The sputtering apparatus according to claim 1, wherein the sputtering apparatus does not have a member for shielding the non-evaporable getter pump from the target.

13. The sputtering apparatus according to any one of claims 1 to 12, wherein the non-evaporable getter material constituting the non-evaporable getter pump is Ti, Zr, V, Al, Ta, W, Mo, Hf, Nb, Fe, or an alloy containing these as a main component.

14. a chamber in which the substrate is housed; a cylindrical target disposed inside the chamber so as to face the film-forming surface of the substrate; a non-evaporable getter pump provided inside the chamber; a rotation means for rotating the target, a virtual line segment connecting the rotation center of the target and the position of the non-evaporable getter pump in a virtual plane perpendicular to the rotation axis of the target is an angle defined in polar coordinates with the rotation center of the target as the origin, the angle being positive in a direction toward the film formation surface with respect to the position of a virtual plane that includes the rotation axis of the target and is parallel to the film formation surface of the substrate, and the angle is not included in the range of 45 degrees to 135 degrees; The non-evaporable getter pump is disposed within 30 cm of the target. A sputtering device characterized by:

15. a chamber in which the substrate is housed; a cylindrical target disposed inside the chamber so as to face the film-forming surface of the substrate; a non-evaporable getter pump provided inside the chamber; a rotation means for rotating the target, a sputtering apparatus in which an imaginary line segment connecting the rotation center of the target and the position of the non-evaporable getter pump in an imaginary plane perpendicular to the rotation axis of the target is an angle defined as a polar coordinate with the rotation center of the target as the origin, the angle being positive in a direction toward the film formation target surface with respect to the position of an imaginary plane including the rotation axis of the target and parallel to the film formation target surface of the substrate, and the angle is not within a range of 45 degrees to 135 degrees; A plurality of the targets are provided, A sputtering apparatus characterized in that the non-evaporable getter pump is disposed between a plurality of the targets.

16. A method for manufacturing an electronic device, comprising the step of forming a thin film on a substrate using the sputtering apparatus according to any one of claims 1 to 15.

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