Magnet assembly for magnetron sputtering device

Abstract

According to one embodiment, a magnet assembly of a magnetron sputtering device includes: a yoke; an electromagnet, which is arranged on the yoke and has different magnetic poles in a direction perpendicular to the yoke; and a permanent magnet, which is arranged on the yoke in a manner separated from the electromagnet and surrounds at least a portion of the electromagnet.

Description

Technical Field

[0001] The invention relates to a magnet assembly of a magnetron sputtering device. Background Art

[0002] A sputtering device is a device used to deposit a thin film on a substrate when producing semiconductors, FPDs (LCD, OLED, etc.) or solar cells. In addition, the sputtering device can also be used in a roll-to-roll device. As one of them, the technology used by the magnetron sputtering device is to inject gas into a chamber in a vacuum state and generate plasma, and after the ionized gas particles collide with the target material to be deposited, the particles sputtered by the impact are deposited on the substrate. At this time, in order to form magnetic flux lines on the target material, the magnet unit is arranged behind the target material so that it is opposite to the substrate. That is, the substrate is arranged in front of the target material, and the magnet unit is arranged behind the target material.

[0003] The magnetron sputtering device is widely used because it has the following advantages: it can manufacture thin films in a relatively low temperature environment, particles accelerated by an electric field can be densely deposited on a substrate, and the deposition speed is fast.

[0004] On the one hand, a continuous inline system or a cluster type system is used to deposit a thin film on a large-area substrate. The continuous inline system and the cluster type system provide a plurality of processing chambers between a loading chamber and an unloaded chamber, and the substrate loaded through the loading chamber passes through the plurality of processing chambers for a continuous process. In such a continuous inline system and the cluster type system, a sputtering device is provided in at least one processing chamber, and a magnet unit is arranged at a certain interval.

[0005] However, due to the fixed magnetic field generated by the magnet unit, the plasma density according to the electric field and the magnetic field can determine the erosion of the target surface. In particular, at the edge of the magnet unit, that is, at least one end in the length direction, a ground potential is applied, and the plasma density at the edge of the substrate is greater than that in other areas. Therefore, the sputtering speed at the edge of the target is faster than that in other areas. As a result, the thickness of the thin film deposited on the substrate is unevenly distributed, resulting in a problem of decreased film quality distribution, and due to the difference in plasma density, a specific part of the target is over-eroded, resulting in a problem of reduced target efficiency.

[0006] To solve the above problem, a target material whose edge thickness is greater than that of the central part can be used. To produce the above target material, the central part of the planar target material must be ground to make it thinner, and the planar target material needs to be processed additionally. As a result, there is a problem of material loss during the processing of the planar target material, and the cost is increased due to the additional process. In addition, during the processing of the target material, problems such as target material damage may occur.

[0007] Other methods to solve the above problems include: using a shunt to adjust the magnetic field strength on the target surface; using a pad to adjust the distance at the edge of the magnet; or adding a Z-axis motor at the edge of the magnet. However, the above methods will increase the manufacturing cost, and the magnetic field strength needs to be adjusted manually. In addition, since it is impossible to adjust the magnetic field strength locally, it needs to be repeated several times, which takes a long time. Summary of the invention

[0008] Technical problems to be solved

[0009] The purpose of one embodiment is to provide a magnet assembly for a magnetron sputtering device, in which the vertical magnetic field on the target is zero (hereinafter, B⊥0), that is, the local horizontal magnetic field is maximum, and the plasma density is greater than that in other areas. Therefore, not only can the position where the target consumption (erosion) is concentrated be moved in the left and right direction (X axis), but also can be moved in the up and down direction (Y axis).

[0010] Furthermore, an object of an embodiment is to provide a magnet assembly of a magnetron sputtering device that moves B⊥0 by a simple control method.

[0011] Technical solutions to its technical problems

[0012] According to one embodiment, a magnet assembly of a magnetron sputtering device includes: a yoke; an electromagnet, which is arranged on the yoke and has different magnetic poles in a direction perpendicular to the yoke; and a permanent magnet, which is arranged on the yoke in a manner separated from the electromagnet and surrounds at least a portion of the electromagnet.

[0013] The permanent magnet has a horseshoe shape that is open in a direction parallel to the yoke, and the electromagnet is arranged inside the permanent magnet.

[0014] The permanent magnet is Character shape.

[0015] As the power applied to the electromagnet changes, the position where the vertical magnetic field on the target of the magnetron sputtering device is zero moves.

[0016] The electromagnet includes: a magnetic core fixed on the magnetic yoke and arranged inside the permanent magnet; and a coil wound around the magnetic core.

[0017] The magnet assembly of the magnetron sputtering device further includes a control unit for changing the power applied to the coil.

[0018] The distance from the electromagnet to the center of the permanent magnet is the same as the distance from the electromagnet to the side of the permanent magnet, or the distance from the electromagnet to the center of the permanent magnet is greater than the distance from the electromagnet to the side of the permanent magnet.

[0019] Effects of the Invention

[0020] According to an embodiment, B⊥0 formed on the target can be moved not only in the left-right direction but also in the up-down direction, thereby preventing local excessive erosion of the target.

[0021] Furthermore, B⊥0 formed on the target can be easily moved by controlling the strength of the electromagnet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a side view schematically showing the structure of a sputtering device according to one embodiment.

[0023] Figure 2 FIG. 4 is a top view of a magnet assembly according to an embodiment.

[0024] Figure 3 FIG. 1 is a plan view of a magnet assembly showing a position where a perpendicular magnetic field is zero (hereinafter, B⊥0) according to an embodiment.

[0025] Figure 4 A side view of a magnet assembly schematically showing the state of B⊥0 changing as the strength of the electromagnet increases according to one embodiment.

[0026] Figure 5 for Figure 4 A plan view of a magnet assembly.

[0027] Figure 6 FIG. 1 is a side view schematically showing the state of B⊥0 changing as the strength of the electromagnet decreases according to one embodiment.

[0028] Figure 7 for Figure 6 A plan view of a magnet assembly.

[0029] Figure 8 FIG. 4 is a top view of a magnet assembly according to an embodiment.

[0030] Fig. 9FIG. 4 is a top view of a target showing B⊥0 on the target according to an embodiment.

[0031] Fig.10 FIG. 1 is a top view of a target showing the morphology of B⊥0 as the strength of an electromagnet changes according to an embodiment.

[0032] Fig.11 For along Fig.10 Cross-sectional view of the target material of line II. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The same figure numbers in the various drawings represent the same components. Various modifications may be made to the embodiments described below. In addition, in the process of describing the present invention, when it is determined that the specific description of the known technology unnecessarily obscures the key points of the embodiments, the detailed description thereof will be omitted.

[0034] Furthermore, when describing the constituent elements of the embodiments, terms such as first, second, A, B, (a), (b), etc. may be used. However, the above terms are used only to distinguish the constituent element from other constituent elements, and are not used to limit the nature, arrangement or order of the corresponding constituent elements. When describing that a constituent element is "connected" or "combined" with other constituent elements, the constituent element may be directly connected or combined with the other constituent elements, and each constituent element may also be "connected" or "combined with" other constituent elements.

[0035] The components having the same functions as the components in any one embodiment are described in other embodiments using the same names. Unless a counterexample is mentioned, the description recorded in any one embodiment can be applied to other embodiments, and thus, the specific description is omitted within the scope of repetition.

[0036] Figure 1 A side view schematically showing the structure of a sputtering device according to an embodiment. Figure 2 is a top view of a magnet assembly according to an embodiment, Figure 3 FIG. 1 is a plan view of a magnet assembly showing a position where a perpendicular magnetic field is zero (hereinafter, B⊥0) according to an embodiment.

[0037] Reference Figure 1 and Figure 2 According to an embodiment, a sputtering device 1 may include a magnet assembly 10 , a substrate 20 , a substrate fixing unit 30 , a target 40 , a backing plate 50 , and a control unit 60 .

[0038] The magnet assembly 10 can include a plurality of electromagnets 11, 91, a permanent magnet 12, and a yoke 13. The magnet assembly 10 can form a fixed magnetic field with a certain strength on the target 40 by using the electromagnets 11 and the permanent magnets 12. Plasma can be formed on the surface of the target 40 by the fixed magnetic field and the electric field applied from the outside. The plasma density is determined by the fixed magnetic field and the applied electric field. The plasma is sputtered on the surface of the target 40 to deposit a thin film on the substrate 20.

[0039] The fixed magnetic field formed by the magnet assembly 10 on the target 40 can include a vertical magnetic field and / or a horizontal magnetic field. For the surface of the target 40, at a position where the vertical magnetic field (the magnetic flux line component perpendicular to the target surface) is zero (hereinafter referred to as B⊥0), the horizontal magnetic field (the magnetic flux line component parallel to the target surface) becomes the maximum locally, and since the plasma density in the corresponding area is greater than that in other areas, the sputtering speed is faster. Figure 3 B⊥0 indicated by a dotted line in FIG. 1 is a conceptual diagram of B⊥0 formed on the surface of the substrate 40 . B⊥0 can be formed between the electromagnet 11 and the permanent magnet 12 . The position of B⊥0 can be different depending on the distance between the target 40 and the magnet assembly 10 .

[0040] When a thin film is deposited on a large-area substrate 20 larger than the magnet assembly 10, two or more magnet assemblies 10 may be provided. In this case, at least two or more magnet assemblies 10 are arranged with the same size and structure and at the same interval.

[0041] The yoke 13 is plate-shaped and can support the plurality of electromagnets 11 and 91 and the permanent magnets 12. For example, the yoke 13 can have an image extending in the longitudinal direction.

[0042] The electromagnets 11 disposed at both ends of the yoke 13 among the plurality of electromagnets 11, 91 can be surrounded by the permanent magnet 12. The electromagnet 11 can be disposed on the yoke 13 in a manner separated from the permanent magnet 12. A control unit (not shown) disposed outside can control the strength of the electromagnet 11. For example, the electromagnet 11 can include a coil 111 and a magnetic core 112. The coil 111 is wound along the outer surface of the magnetic core 112 in a clockwise or counterclockwise direction. The coil 111 can generate a magnetic field. The magnetic core 112 can amplify the magnetic field formed by the coil 111. The magnetic core 112 is fixed on the yoke 13 and disposed on the inner side of the permanent magnet 12. For example, the magnetic core 112 can be an iron core or a permanent magnet.

[0043] The electromagnet 91 disposed in the center of the yoke 13 among the plurality of electromagnets 11 and 91 is disposed between the permanent magnets 12 located at both ends of the yoke 13. The electromagnet 91 may include a plurality of rows, for example, three rows.

[0044] The permanent magnet 12 can be disposed at both ends of the yoke 13. The permanent magnet 12 is disposed at a distance from the electromagnet 11 on the yoke 13 and surrounds at least a portion of the electromagnet 11. The permanent magnet 12 interacts with the electromagnet 11 to generate a magnetic field.

[0045] The permanent magnet 12 may include a central portion 12a and two side portions 12b and 12c formed to protrude in the same direction from both ends of the central portion 12a. The electromagnet 11 may be disposed between the two side portions 12b and 12c of the permanent magnet 12.

[0046] The plurality of electromagnets 11, 91 and the permanent magnet 12 can form a closed curve B⊥0 on the target 40. For example, the upper part of the permanent magnet 12 is an N pole and the lower part is an S pole. The upper part of the electromagnet 11 can be an S pole. Figure 2 As a reference, the electromagnets 91 are formed into three rows, the upper part of the electromagnets 91 arranged in the middle row can be the same S pole as the electromagnets 11, and the upper part of the electromagnets 91 arranged in the left and right rows can be the same N pole as the permanent magnets 12. At this time, the plurality of electromagnets 11, 91 and the permanent magnets 12 can form a substantially elliptical B⊥0 on the target 40. Here, the "upper part" refers to the part away from the yoke 13, that is, Figure 2 On the other hand, the "lower part" is the part in contact with the yoke 13, that is, Figure 2 The obscured part.

[0047] As another example, the upper portion of the permanent magnet 12 can be an S pole, and the upper portion of the electromagnet 11 can be an N pole. Figure 2 The electromagnets 91 are formed in three rows, the upper portions of the electromagnets 91 arranged in the middle row have the same N pole as the electromagnets 11 , and the upper portions of the electromagnets 91 arranged in the left and right rows have the same S pole as the permanent magnets 12 .

[0048] The permanent magnet 12 can have a horseshoe shape that is open in a direction parallel to the yoke 13. For example, the permanent magnet 12 can have Character shape. The U-shaped permanent magnet 12 may include a portion whose width increases or decreases toward the opening. For example, the width of the permanent magnet 12 gradually increases or decreases toward the opening. The openings of the permanent magnets 12 disposed at both ends of the yoke 13 may face each other. The electromagnet 11 may be formed on the inner side of the permanent magnet 12. Since the electromagnet 11 is disposed on the inner side of the permanent magnet 12, the electromagnet 11 and the permanent magnet 12 may form a substantially U-shaped B⊥0. As the power applied to the electromagnet 11 changes, the position where the vertical magnetic field is zero on the target material 40, that is, B⊥0, may move. For example, the width of B⊥0 increases or decreases, and B⊥0 moves up or down. In other words, B⊥0 may be moved up, down, left, and right only by controlling the electromagnet 11. The specific content of the movement of B⊥0 will be described in detail. Figures 4 to 7 is described in.

[0049] The substrate 20 may be a substrate for manufacturing semiconductors, FPD (LCD, OLED, etc.), solar cells, etc., and may be a silicon wafer, glass, etc. Also, the substrate 20 may be a film-type substrate for roll-to-roll.

[0050] The substrate fixing part 30 is arranged opposite to the magnet assembly 10, that is, facing each other or being inclined at a certain angle and separated by a certain distance. At this time, the substrate fixing part 30 can be arranged on the upper side, the lower side, or the side in the device, and the magnet assembly 10 can be arranged to face it. For example, when the substrate fixing part 30 is arranged on the lower side, the magnet assembly 10 is arranged on the upper side; when the substrate fixing part 30 is arranged on the upper side, the magnet assembly 10 is arranged on the lower side. In addition, when the substrate fixing part 30 is arranged vertically on the side, the magnet assembly 10 is arranged on the other side facing it.

[0051] The substrate fixing part 30 fixes the substrate 20 so that the deposition material can be uniformly deposited on the substrate 20. When the substrate 20 is fixed to the substrate fixing part 30, the edge of the substrate 20 can be fixed by a fixing means or the like, or the substrate 20 can be fixed at the back of the substrate 20. The substrate fixing part 30 supports and fixes the entire back of the substrate 20, and is formed into a substantially quadrilateral or circular shape having the image of the substrate 20. In addition, the substrate fixing part 30 is to fix the edge portion of the substrate 20, and four rods are arranged at a certain interval in the upper, lower, left and right directions, and as the edges of the rods contact each other, the central part is formed into a four-sided frame shape of emptiness. On the one hand, the substrate fixing part 30 moves in one direction in a state where the substrate is fixed. For example, a thin film is deposited on the substrate 20 in one direction. Therefore, a moving means (not shown) for moving the substrate fixing part 30 is arranged on the side of the fixed substrate fixing part 30 where the substrate is not fixed. The moving means may include a roller that moves by contacting the substrate fixing part 30, and a magnetic moving means that moves by using a magnetic force and is separated from the substrate fixing part 30. In addition, a part of the substrate fixing part 30 may also function as the moving means. Furthermore, when the sputtering device is a stationary type, the fixing means may not be required. In this case, the substrate fixing part 30 may have a lifting pin for lifting the substrate 20.

[0052] The target 40 is fixed to the backing plate 50 and is composed of a substance to be deposited on the substrate 20. The target 40 can be a metal substance or an alloy including a metal substance. In addition, the target 40 can be a metal oxide, a metal nitride or a dielectric. For example, the target 40 can use a material whose main component is an element selected from Mg, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Pd, Pt, Cu, Ag, Au, Zn, Al, In, C, Si and Sn. On the one hand, the overall thickness of the backing plate 50 and the target 40 can be formed to be about 5 mm to 50 mm.

[0053] The backing plate 50 is disposed between the magnet assembly 10 and the substrate fixing portion 30. Furthermore, the target 40 is fixed to one side of the backing plate 50. That is, the target 40 is disposed on one side of the backing plate 50 facing the substrate 20. Alternatively, the target 40 may be disposed on the upper side of the magnet assembly 10 without disposing the backing plate 50.

[0054] The control unit 60 can change the power applied to the electromagnet 11. For example, the control unit 60 can change the magnitude of the voltage or current applied to the coil 111.

[0055] Figure 4 A side view of a magnet assembly schematically showing the state of B⊥0 changing as the strength of the electromagnet increases according to one embodiment, Figure 5 for Figure 4 A plan view of a magnet assembly. Figure 4 The position of the target 40 is indicated by a dotted line.

[0056] Reference Figure 4 and Figure 5 , the magnet assembly 10 can move B⊥0. When the control unit 60 changes the current and / or voltage applied to the electromagnet 11, it can change the magnetic field generated in the electromagnet 11 and the permanent magnet 12. Thus, B⊥0 formed on the target 40 can be moved.

[0057] Reference Figure 5 When the strength of the electromagnet 11 increases, for example, when 5A or 10A is applied to the electromagnet, B⊥0 expands outward compared to when 0A is applied, that is, when no power is applied to the electromagnet. In other words, B⊥0 moves from the electromagnet 11 to the permanent magnet 12. Figure 4 and Figure 5 , B⊥0 in the initial state is illustrated as B⊥0 0A; when the current flowing through the electromagnet 11 is 5A, B⊥0 is illustrated as B⊥05A; and when the current flowing through the electromagnet 11 is 10A, B⊥0 is illustrated as B⊥0 10A.

[0058] Figure 6 FIG. 1 is a side view schematically showing the state of B⊥0 changing as the strength of the electromagnet decreases according to one embodiment. Figure 7 for Figure 6 A plan view of a magnet assembly. Figure 4 The position of the target 40 is indicated by a dotted line.

[0059] Reference Figure 6 and Figure 7 , when the strength of the electromagnet 11 decreases, B⊥0 gathers inward. In other words, B⊥0 moves from the permanent magnet 12 toward the electromagnet 11. Figure 6 and Figure 7 , B⊥0 in the initial state is illustrated as B⊥0 0A; when the current flowing through the electromagnet 11 is -5A, B⊥0 is illustrated as B⊥0-5A; and when the current flowing through the electromagnet 11 is -10A, B⊥0 is illustrated as B⊥0-10A.

[0060] Figure 8 is a top view of a magnet assembly according to an embodiment, Fig. 9 FIG. 4 is a top view of a target showing B⊥0 on the target according to an embodiment.

[0061] Reference Figure 8 and Fig. 9, the distance L2 from the electromagnet 11 to the central portion 12a is the same as the distance from the electromagnet 11 to the side portions 12b and 12c of the permanent magnet 12, or the distance L2 from the electromagnet 11 to the central portion 12a is greater than the distance from the electromagnet 11 to the side portions 12b and 12c of the permanent magnet 12. During the intensity variation of the electromagnet 11, the vertical displacement D2 of B⊥0 is greater than the horizontal displacement D1.

[0062] For example, the electromagnet 11 can be more affected by the N-pole of the permanent magnet 12, and thus, the vertical displacement D2 of B⊥0 is greater than the horizontal displacement D1. In the distribution of magnetic flux lines formed between the electromagnet 11 and the permanent magnet 12, the vertical displacement part (Y-axis direction) is more affected by the change in the strength of the electromagnet than the horizontal displacement part (X-axis direction) because the unit area of ​​the permanent magnet of the N-pole around the electromagnet is larger.

[0063] For example, the magnetron sputtering device can include a left and right driving magnet assembly 10 (see Figure 1 ) is provided with a driving unit (not shown). The magnetron sputtering device fully ensures the vertical displacement range of B⊥0 through the control unit, and fully ensures the horizontal displacement range of B⊥0 through the driving unit. Even without a driving unit, the vertical displacement range of B⊥0 can be ensured by adjusting the strength of the electromagnet 11.

[0064] Fig.10 The above diagram is a target material showing the shape of B⊥0 as the intensity of the electromagnet changes according to one embodiment. Fig.11 For along Fig.10 Cross-sectional view of the target material of line II.

[0065] Reference Fig.10 and Fig.11 , the initial state B⊥0a moves left and right and forms sputtering on the surface of the target 40, and the expanded B⊥0b and the reduced B⊥0c also move left and right and form sputtering on the surface of the target 40. The problem of local excessive erosion may occur in the overlapping area A. In this regard, the magnet assembly 10 (refer to Figure 1 ) The overlapping area A is expanded by moving the boundary of B⊥0, thereby reducing the erosion depth in the overlapping area A.

[0066] In summary, the description has been made with reference to limited drawings and embodiments. However, a person skilled in the art can make various modifications and changes based on the above description. For example, the described techniques are performed in a different order than the described methods, and / or the described constituent elements are combined or combined in a different form than the described methods, or replaced or substituted with other constituent elements or equivalents to achieve reasonable results. Therefore, other embodiments, other embodiments and equivalent substitutions within the scope of the claims are also included in the scope of the claims of the present invention.

Claims

1. A magnet assembly for a magnetron sputtering device, comprising: A yoke having a shape extending in a length direction; a plurality of electromagnets, arranged on the magnetic yoke, and having different magnetic poles in a direction perpendicular to the magnetic yoke; as well as A plurality of permanent magnets, each of which is disposed at both ends of the yoke and has a horseshoe shape that is open in a direction parallel to the yoke, and the openings of the permanent magnets disposed at both ends of the yoke face each other, Among the plurality of electromagnets, first electromagnets disposed at both ends of the yoke are disposed inside the permanent magnet in a manner separated from the permanent magnet and surrounded by the permanent magnet. Among the plurality of electromagnets, a second electromagnet disposed in a central portion of the yoke includes a plurality of columns and is disposed between the permanent magnets located at both ends of the yoke. The upper portion of the first electromagnet and the upper portion of the permanent magnet are of opposite polarity, Among the second electromagnets, the upper parts of the second electromagnets arranged in the middle row have the same pole as the upper part of the first electromagnet, and the upper parts of the second electromagnets arranged in the left and right rows have the same pole as the upper part of the permanent magnet. A variable electric power is applied to the first electromagnet, and as the electric power applied to the first electromagnet changes, a position where the vertical magnetic field on the target of the magnetron sputtering device is zero moves.

2. The magnet assembly of the magnetron sputtering device according to claim 1, wherein: The first electromagnet comprises: a magnetic core fixed to the magnetic yoke and arranged inside the permanent magnet; and A coil is wound around the magnetic core.

3. The magnet assembly of the magnetron sputtering device according to claim 2, wherein: A control unit for varying the power applied to the coil is also included.

4. The magnet assembly of the magnetron sputtering device according to claim 1, wherein: The permanent magnet includes a central portion and two side portions protruding from both ends of the central portion in the same direction. The first electromagnet is disposed between two side portions of the permanent magnet. The distance from the first electromagnet to the center of the permanent magnet is the same as the distance from the first electromagnet to the side of the permanent magnet, or the distance from the first electromagnet to the center of the permanent magnet is greater than the distance from the first electromagnet to the side of the permanent magnet.

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