A three-dimensional magnetron sputtering cathode and a three-dimensional magnetron sputtering system

Abstract

This invention provides a three-dimensional magnetron sputtering cathode and a three-dimensional magnetron sputtering system, relating to the field of magnetron sputtering technology, to solve the technical problem of low target utilization caused by the formation of periodic sputtering pits on the target surface in existing magnetron sputtering cathodes; a three-dimensional magnetron sputtering cathode has a water-cooled jacket with a first through hole along the axial direction, and several annular sputtering targets are sequentially disposed along the axial direction on the inner wall of the first through hole, with the inner ring of the several annular sputtering targets forming a sputtering space; several magnet assembly units are sequentially slidably disposed along the axial direction on the water-cooled jacket, each magnet assembly unit including an annular magnetic yoke and several magnets, all magnets in the same magnet assembly unit having the same magnetic pole facing the sputtering space, and the magnetic poles of the magnets in adjacent magnet assembly units being opposite; a driving mechanism drives all magnet assembly units to reciprocate axially to adjust the axial relative position of the magnet assembly units and the annular sputtering targets, thereby obtaining a sputtering deposition process with high target utilization and high deposition rate.

Description

Technical Field

[0001] This invention relates to the field of magnetron sputtering technology, specifically to a three-dimensional magnetron sputtering cathode and a three-dimensional magnetron sputtering system. Background Technology

[0002] Magnetron sputtering is a widely used physical vapor deposition technique. Its basic principle is to use a magnetic field to confine electrons, increasing the probability of collisions between electrons and process gases, generating high-density plasma, which bombards the target surface, causing target atoms to deposit on the workpiece surface to form a thin film. The magnetron sputtering cathode is the core component of the entire coating system, and its structural design directly determines key process indicators such as target utilization, deposition rate, and film uniformity.

[0003] In traditional magnetron sputtering cathodes, the magnetic field is generated by a stationary magnetic strip assembly, forming a single closed magnetic field loop on the target surface. During actual sputtering, electrons are confined to a specific magnetic field region, resulting in periodic sputtering channels on the target surface that follow the distribution of the magnetic field. A significant amount of target material remains unutilized outside these channels. Therefore, the target utilization rate of traditional magnetron sputtering cathodes is generally low, leading to wasted target material costs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the first objective of this invention is to provide a three-dimensional magnetron sputtering cathode to solve the technical problem of low target utilization caused by the formation of periodic sputtering pits on the target surface in existing magnetron sputtering cathodes.

[0005] To address the aforementioned technical problems, this invention provides a three-dimensional magnetron sputtering cathode, comprising: The water-cooled jacket has a first through hole along the axial direction; Several annular sputtering targets are sequentially disposed along the axial direction on the inner wall of the first through hole, and the inner ring of the several annular sputtering targets forms a sputtering space; Several magnet assembly units are slidably disposed on the water-cooling jacket along the axial direction. Each magnet assembly unit includes an annular magnetic yoke and several magnets. Several magnets are disposed circumferentially on the inner wall of the annular magnetic yoke and form an annular closed magnetic ring. All magnets in the same magnet assembly unit have the same magnetic pole facing the sputtering space, and the magnetic poles of the magnets in adjacent magnet assembly units are opposite. The drive mechanism connects to the water-cooled jacket and drives all magnet assembly units to reciprocate axially to adjust the axial relative position of the magnet assembly units and the annular sputtering target.

[0006] With the above structure, the three-dimensional magnetron sputtering cathode of the present invention has the following advantages: By cooperating with the water-cooled jacket, several annular sputtering targets, several magnet component units and the driving mechanism, the opposite magnetic poles of adjacent magnet component units are used to constrain the movement of electrons on the target surface. The hollow cathode effect is used to increase the plasma density, and the effective sputtering area per unit area is greatly increased, thereby obtaining a deposition rate higher than that of traditional cathodes. At the same time, the driving mechanism drives all magnet component units to move back and forth along the axial direction, causing the spatial position of the magnetic field to change synchronously. This makes the ion bombardment position, which was originally concentrated in a fixed annular region under a static magnetic field, continuously move along the target axis, thereby uniformly distributing the sputtering energy over a wider target area, avoiding local over-etching, and ultimately achieving a significant improvement in target utilization, which is especially suitable for thick film preparation.

[0007] As an improvement, the water-cooled jacket includes an upper flange, a lower flange, an inner sleeve, and an outer sleeve. The inner sleeve and the outer sleeve are connected between the upper flange and the lower flange and are arranged in an inward and outward manner. A water-cooled cavity is formed between the inner sleeve and the outer sleeve. A first through hole is provided on the inner sleeve. Several magnet assembly units are slidably disposed in the water-cooled cavity along the axial direction. With this structure, the water-cooled cavity is formed by the upper flange, the lower flange, the inner sleeve, and the outer sleeve, and the magnet assembly units are slidably disposed in the water-cooled cavity. On the one hand, the circulating cooling water is used to efficiently dissipate heat from the magnet assembly units, preventing overheating caused by long-term sputtering. On the other hand, the overall structure is compact, with only one inner sleeve separating the magnet assembly units from the target material, resulting in minimal magnetic field attenuation and ensuring sputtering efficiency.

[0008] As an improvement, adjacent magnet component units are connected by a positioning mechanism. This structure ensures the relative positional accuracy of all magnet component units in the circumferential direction, while also ensuring that all magnet component units can move synchronously and smoothly under the drive mechanism, avoiding misalignment of adjacent magnetic poles caused by the displacement of a single unit.

[0009] As an improvement, the positioning mechanism includes several positioning pins and several second through holes. Several second through holes are provided on each annular magnetic yoke along the circumference. The several second through holes on all annular magnetic yokes are coaxially arranged. The positioning pins are inserted into the second through holes, and each positioning pin is inserted into the second through holes of at least two adjacent annular magnetic yokes. With this structure, the rapid alignment and firm connection between each magnet component unit are realized. The assembly is convenient and there is no extra movement gap, ensuring the overall rigidity after the multi-unit stack is completed.

[0010] As an improvement, the drive mechanism includes a drive cylinder, a drive shaft, and a support base. The drive cylinder is connected to the bottom end of the water-cooled jacket, and the drive shaft is slidably connected to the bottom end of the water-cooled jacket along the vertical direction. A support base is provided at the upper end of the drive shaft, and the support base is connected to the bottom end of the magnet assembly unit. The drive cylinder drives the drive shaft to move vertically. With this structure, the entire magnet assembly unit can be moved axially and reciprocally by extending and retracting the cylinder. The structure is simple, the response is fast, and the control is convenient. It can achieve stable periodic motion, which is beneficial for adjusting the relative position of the magnetic field and the target material in real time during the sputtering process.

[0011] As an improvement, a groove is provided on the upper surface of the support base, and the bottom end of the annular magnetic yoke of the lowest magnet component unit is engaged in the groove. This structure achieves a stable mechanical connection between the support base and the magnet component unit, preventing radial swaying or detachment during high-speed reciprocating movement, and ensuring transmission accuracy and reliability.

[0012] As an improvement, the water-cooling jacket is provided with a guide hole, and the drive mechanism also includes a shaft seal. The drive shaft is slidably connected in the guide hole through the shaft seal. With this structure, the shaft seal not only plays a sealing role, but also provides precise linear guidance for the drive shaft, reducing motion friction and eccentric wear, and extending the service life of the drive mechanism.

[0013] As an improvement, the inner wall of the annular magnetic yoke is provided with an annular mounting groove along the circumference, and several magnets are connected in the annular mounting groove. With this structure, the mounting groove limits the magnets axially and radially, ensuring that all magnets are evenly distributed along the circumference and form a complete annular closed magnetic ring, which simplifies the assembly process and avoids the magnets from falling off or shifting during movement.

[0014] As an improvement, the driving mechanism drives all magnet component units to reciprocate vertically by a distance equal to half the magnet spacing between adjacent magnet component units. With this structure, this specific distance ensures that the deepest point of the sputtering pit corresponding to a magnet component unit overlaps with the original shallowest point after the movement, thereby making the average etching depth of each point along the axis more consistent, smoothing out the periodic sputtering pits, achieving the best uniform etching effect for the target material, and further increasing the target material utilization rate to the theoretical maximum value.

[0015] A second objective of the present invention is to provide a three-dimensional magnetron sputtering system, including the aforementioned three-dimensional magnetron sputtering cathode.

[0016] With the above structure, the three-dimensional magnetron sputtering system of the present invention has the following advantages: By cooperating with the water-cooled jacket, several annular sputtering targets, several magnet component units and the driving mechanism, the opposite magnetic poles of adjacent magnet component units are used to constrain the movement of electrons on the target surface, significantly improving the ionization efficiency of the process gas, resulting in a significant increase in plasma density in the sputtering space, thereby obtaining a deposition rate higher than that of traditional cathodes; at the same time, the driving mechanism drives all magnet component units to reciprocate along the axial direction, causing the spatial position of the magnetic field to change synchronously, so that the ion bombardment position, which was originally concentrated in a fixed annular region under a static magnetic field, continues to move along the target axis, thereby uniformly distributing sputtering energy over a wider target area, avoiding local over-etching, and ultimately achieving a significant increase in target utilization, which is especially suitable for thick film preparation. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the three-dimensional magnetron sputtering cathode in this invention.

[0018] Figure 2 for Figure 1 A magnified view of part A in the middle.

[0019] Figure 3 for Figure 1 A magnified view of part B in the middle.

[0020] Figure 4 This is a schematic diagram of the three-dimensional magnetron sputtering cathode structure in this invention.

[0021] Figure 5 This is a three-dimensional structural diagram of the magnet component unit in this invention.

[0022] Figure 6 This is a schematic diagram comparing the target material sputtered by the three-dimensional magnetron sputtering cathode of the present invention with the target material sputtered by the three-dimensional magnetron sputtering cathode of the prior art.

[0023] Reference numerals in the attached drawings: 1. First through hole; 2. Annular sputtering target; 3. Annular magnetic yoke; 4. Magnet; 5. Upper flange; 6. Lower flange; 7. Inner sleeve; 8. Outer sleeve; 9. Water-cooled cavity; 10. Positioning pin; 11. Second through hole; 12. Drive cylinder; 13. Drive shaft; 14. Support base; 15. Groove; 16. Guide hole; 17. Shaft seal; 18. Annular mounting groove. Detailed Implementation

[0024] The following detailed description of a three-dimensional magnetron sputtering cathode and a three-dimensional magnetron sputtering system according to the present invention is provided in conjunction with the accompanying drawings.

[0025] like Figures 1 to 6As shown, a three-dimensional magnetron sputtering cathode includes a water-cooled jacket, several annular sputtering targets 2, several magnet assembly units, and a driving mechanism. The water-cooled jacket is cylindrical in shape and has a first through hole 1 along its axial direction. Several annular sputtering targets 2 are sequentially installed on the inner wall of the first through hole 1 along the axial direction and are attached vertically to each other. The inner rings of these annular sputtering targets 2 together form a sputtering space, in which the workpiece to be coated is placed.

[0026] Specifically, such as Figure 1 As shown, the water-cooled jacket includes an upper flange 5, a lower flange 6, an inner sleeve 7, and an outer sleeve 8. The inner sleeve 7 and the outer sleeve 8 are connected between the upper flange 5 and the lower flange 6 and are arranged in an inner-outer configuration. Both the inner sleeve 7 and the outer sleeve 8 are cylindrical and concentrically arranged. Their upper and lower ends are welded and fixed to the upper flange 5 and the lower flange 6, respectively, thus forming a sealed water-cooled cavity 9 between the inner sleeve 7 and the outer sleeve 8. The first through hole 1 is the inner hole of the inner sleeve 7. Cooling water is introduced into the water-cooled cavity 9 from an external water source and circulates to remove the heat generated during the sputtering process.

[0027] Several magnet assembly units are slidably mounted sequentially along the axial direction on the water-cooling jacket. Specifically, these magnet assembly units are housed within the water-cooling cavity 9, with adjacent magnet assembly units touching vertically. The water-cooling cavity 9 has a certain radial thickness, sufficient to allow the magnet assembly units to slide axially within it, while ensuring that the magnet 4 and the annular sputtering target 2 are separated only by an inner sleeve 7, thereby minimizing magnetic field attenuation and ensuring sputtering efficiency.

[0028] like Figure 5 As shown, each magnet assembly unit includes an annular yoke 3 and several magnets 4. An annular mounting groove 18 is formed circumferentially on the inner wall of the annular yoke 3. Several arc-shaped magnets 4 (e.g., neodymium iron boron magnets) are sequentially embedded in the annular mounting groove 18, joined end-to-end to form a complete annular closed magnetic ring. The annular mounting groove 18 provides axial and radial restraint for the magnets 4, ensuring that all magnets 4 are evenly distributed along the circumference and do not fall off or shift during the reciprocating movement of the magnet assembly unit. Within the same magnet assembly unit, all magnets 4 have the same magnetic pole facing the sputtering space, for example, all N poles or all S poles. However, adjacent magnet assembly units stacked axially have magnets 4 with opposite magnetic pole arrangements; that is, if the magnets 4 of the previous unit face the sputtering space with N poles, then the magnets 4 of the next unit face the sputtering space with S poles, and so on.

[0029] To maintain the precise relative positions of all magnet component units in the circumferential direction and ensure their synchronized movement as a whole, adjacent magnet component units are connected by a positioning mechanism. For example... Figure 5As shown, the positioning mechanism includes several positioning pins 10 and several second through holes 11. Multiple second through holes 11 (e.g., four, spaced at 90° intervals) are evenly distributed circumferentially on each annular magnetic yoke 3. When all the magnet component units are stacked in the order of alternating magnetic poles, the second through holes 11 on each annular magnetic yoke 3 are coaxially aligned, forming axially penetrating pin hole channels. The positioning pins 10 are inserted into the second through holes 11, with each positioning pin 10 inserted into at least two adjacent annular magnetic yokes 3's second through holes 11. In this way, the various magnet component units are firmly connected through the pin hole engagement, ensuring not only rapid alignment during assembly but also the overall rigidity of the stack.

[0030] The drive mechanism is used to drive all magnet component units as a whole to reciprocate axially, thereby dynamically adjusting the axial relative position of the magnet 4 and the annular sputtering target 2. In this embodiment, two sets of drive mechanisms are symmetrically arranged to ensure balanced force and smooth movement. The drive mechanism includes a drive cylinder 12, a drive shaft 13, a support base 14, and a shaft seal 17. The drive cylinder 12 is connected to the bottom end of the water-cooled jacket, and the drive shaft 13 is slidably connected to the bottom end of the water-cooled jacket. The water-cooled jacket is provided with a guide hole 16, and the drive shaft 13 is slidably connected to the guide hole 16 through the shaft seal 17. The upper end of the drive shaft 13 is provided with a support base 14, which is connected to the bottom end of the magnet component unit. The drive cylinder 12 drives the drive shaft 13 to move vertically.

[0031] Specifically, such as Figure 1 and Figure 3 As shown, a set of drive cylinders 12 are fixedly installed on the left and right sides of the bottom end face of the lower flange 6 of the water-cooled jacket. The piston rod of each set of drive cylinders 12 is connected to a drive shaft 13. Two guide holes 16 are correspondingly opened on the lower flange 6 of the water-cooled jacket. A shaft seal 17 (such as a lip seal or mechanical seal) is installed in each guide hole 16. The drive shaft 13 passes through the shaft seal 17 and the guide hole 16 and extends into the interior of the water-cooled jacket. The upper end face of the support base 14 is machined with a groove 15. The bottom end of the annular magnetic yoke 3 of the lowest magnet assembly unit is engaged in the groove 15 to achieve a reliable mechanical connection. The two sets of drive cylinders 12 extend and retract synchronously, driving the entire magnet assembly unit stack to reciprocate axially through the drive shaft 13 and the support base 14. The shaft seal 17 prevents the cooling water in the water-cooled cavity 9 from leaking along the drive shaft 13, and provides precise linear guidance for the drive shaft 13, reducing motion friction and eccentric wear.

[0032] The distance by which the aforementioned drive mechanism moves the magnet assembly unit reciprocally is set to half the distance between the magnets 4 of two adjacent magnet assembly units. The distance between adjacent magnets 4 refers to the distance between the geometric center lines of the respective magnets 4 in two axially adjacent magnet assembly units. In a stationary state, adjacent magnet assembly units with opposite magnetic poles form a closed magnetic loop (i.e., a sputtering raceway). Electrons are confined within this raceway, causing a significant increase in plasma density in this region, thus forming an annular sputtering channel at the corresponding position on the target material. The axial etching depth of this channel is non-uniform: in the region directly opposite the magnet 4 (i.e., where the magnetic pole faces the target surface), the ion bombardment is weaker and the etching is shallower because the magnetic field is parallel to the target surface; while near the midpoint of the line connecting two adjacent magnetic poles, the component of the magnetic field lines perpendicular to the target surface is larger, resulting in the strongest ion bombardment and the deepest etching. Therefore, the axial profile of a sputtering channel exhibits a periodic "shallow-deep-shallow" morphology, as shown in the reference section. Figure 6 As shown in section C. When the drive mechanism moves all magnet component units axially back and forth, and the moving distance is exactly equal to half the distance between adjacent magnets, the bombardment position that was originally at the deepest point will overlap with the original shallowest point after the movement, while the original shallowest point will move to the deepest point; through continuous reciprocating motion, the average bombardment dose at each position along the axial direction tends to be consistent, thereby gradually smoothing out the original periodic deep pits, so that the inner surface of the entire annular sputtering target 2 is uniformly etched, as shown in reference. Figure 6 As shown in D.

[0033] Before sputtering begins, the workpiece to be coated is placed in the sputtering space. A process gas (usually argon) is introduced into the sputtering space. Because the magnetic poles of adjacent magnet assembly units are opposite, a closed magnetic loop is formed in the target surface region between every two adjacent units. N magnet assembly units together form N-1 annular sputtering tracks. Each magnetic loop confines secondary electrons near the target surface, causing them to move along the track. Electrons and argon atoms in the process gas continuously collide to generate argon ions. These argon ions bombard the target surface, forming the sputtering process. The hollow cathode effect increases the plasma density, significantly increasing the effective sputtering area per unit area. Simultaneously, the drive mechanism moves the magnet assembly units back and forth, resulting in a sputtering deposition process with high target utilization (≥70%) and a high deposition rate (0.5~1 μm / min), which is particularly suitable for thick film preparation.

[0034] The present invention also relates to a three-dimensional magnetron sputtering system, including the above-described three-dimensional magnetron sputtering cathode.

[0035] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiment. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

Claims

1. A three-dimensional magnetron sputtering cathode, characterized in that, include: The water-cooled jacket has a first through hole (1) along the axial direction. A plurality of annular sputtering targets (2) are sequentially disposed along the axial direction on the inner wall of the first through hole (1), and the inner rings of the plurality of annular sputtering targets (2) form a sputtering space; A number of magnet component units are slidably disposed on the water-cooling jacket along the axial direction. Each magnet component unit includes an annular magnetic yoke (3) and a number of magnets (4). The magnets (4) are disposed circumferentially on the inner wall of the annular magnetic yoke (3) to form an annular closed magnetic ring. All the magnets (4) of the same magnet component unit have the same magnetic pole facing the sputtering space, and the magnetic poles of the magnets (4) of adjacent magnet component units are opposite. The drive mechanism is connected to the water-cooled jacket and drives all the magnet assembly units to move axially back and forth to adjust the axial relative position of the magnet assembly units and the annular sputtering target (2).

2. The three-dimensional magnetron sputtering cathode according to claim 1, characterized in that, The water-cooled jacket includes an upper flange (5), a lower flange (6), an inner sleeve (7), and an outer sleeve (8). The inner sleeve (7) and the outer sleeve (8) are connected between the upper flange (5) and the lower flange (6) and are arranged in an inner-outer configuration. A water-cooled cavity (9) is formed between the inner sleeve (7) and the outer sleeve (8). The first through hole (1) is provided on the inner sleeve (7). A plurality of magnet assembly units are slidably disposed in the water-cooled cavity (9) along the axial direction.

3. The three-dimensional magnetron sputtering cathode according to claim 1, characterized in that, Adjacent magnet component units are connected by a positioning mechanism.

4. The three-dimensional magnetron sputtering cathode according to claim 3, characterized in that, The positioning mechanism includes a plurality of positioning pins (10) and a plurality of second through holes (11). Each of the annular magnetic yokes (3) is provided with a plurality of second through holes (11) along the circumferential direction. The plurality of second through holes (11) on all the annular magnetic yokes (3) are coaxially arranged. The positioning pins (10) are inserted into the second through holes (11) and each positioning pin (10) is inserted into at least two adjacent annular magnetic yokes (3) in the second through holes (11).

5. The three-dimensional magnetron sputtering cathode according to claim 1, characterized in that, The driving mechanism includes a driving cylinder (12), a driving shaft (13), and a support base (14). The driving cylinder (12) is connected to the bottom end of the water-cooling jacket. The driving shaft (13) is slidably connected to the bottom end of the water-cooling jacket in a vertical direction. The support base (14) is provided at the upper end of the driving shaft (13). The support base (14) is connected to the bottom end of the magnet assembly unit. The driving cylinder (12) drives the driving shaft (13) to move vertically.

6. The three-dimensional magnetron sputtering cathode according to claim 5, characterized in that, The upper surface of the support base (14) is provided with a groove (15), and the bottom end of the annular magnetic yoke (3) of the lowest magnet assembly unit is engaged in the groove (15).

7. The three-dimensional magnetron sputtering cathode according to claim 5, characterized in that, The water-cooled jacket is provided with a guide hole (16), and the drive mechanism also includes a shaft seal (17). The drive shaft (13) is slidably connected in the guide hole (16) through the shaft seal (17).

8. The three-dimensional magnetron sputtering cathode according to claim 1, characterized in that, The inner wall of the annular magnetic yoke (3) is provided with an annular mounting groove (18) along the circumferential direction, and a plurality of magnets (4) are connected in the annular mounting groove (18).

9. The three-dimensional magnetron sputtering cathode according to claim 1, characterized in that, The driving mechanism drives all the magnet component units to move vertically back and forth by a distance equal to half the distance between the magnets (4) of adjacent magnet component units.

10. A three-dimensional magnetron sputtering system, characterized in that, Includes the three-dimensional magnetron sputtering cathode as described in any one of claims 1 to 9.

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