Orthogonal electromagnetic field rotating magnetron sputtering device

Abstract

This application discloses an orthogonal electromagnetic field rotating magnetron sputtering device, including a working cavity, a target, a first magnetic group, and a second magnetic group. Both the first and second magnetic groups include multiple permanent magnets. The first and second magnetic groups are arranged opposite to each other about the center of the working cavity, and the magnetic poles of the permanent magnets are opposite, so that the magnetic lines of force are coupled below the target to form an orthogonal magnetic field parallel to the surface of the target. The orthogonal magnetic field can more effectively apply the Lorentz force to the electrons and prolong the movement path of the electrons, thereby solving the problem of low ionization rate of the reactive gas caused by the rapid bombardment or loss of electrons on the substrate, so as to improve the ionization efficiency. It also includes a first rotating drive mechanism for driving the two magnetic groups to rotate around the center of the working cavity, thereby eliminating the circumferential distribution difference of the magnetic field through the time averaging effect, solving the problem of uneven target sputtering and large film thickness deviation caused by fixed magnetic groups, and improving the target utilization rate and film deposition uniformity.

Description

Technical Field

[0001] This application relates to the field of wafer manufacturing equipment technology, and in particular to an orthogonal electromagnetic field rotating magnetron sputtering device. Background Technology

[0002] Magnetron sputtering is an important technique in physical vapor deposition (PVD). Its working principle is as follows: Inside a vacuum chamber, the target (cathode) and substrate (anode) are respectively positioned on the upper and lower sides of the chamber. Electrons move under the influence of an electric field and collide with argon atoms, ionizing to produce Ar. + And new electronics; Ar + The target material is accelerated and bombarded by an electric field, causing the target atoms to sputter and deposit into a film.

[0003] Magnetic fields are crucial for improving sputtering efficiency, as they can increase gas ionization by confining electron movement.

[0004] Traditional magnetron sputtering apparatus places the magnetron on the back of the target. However, due to limitations in the magnetic pole arrangement and structure, the magnetic field lines in most areas are not parallel to the target surface. This results in insufficient Lorentz force on the electrons, limiting the effect of the plasma and making it difficult to increase the sputtering rate. Furthermore, due to the uneven distribution of the magnetic field on the target surface, even with the use of a rotating magnetron to improve circumferential uniformity, "etching raceways" are still prone to appear in the radial direction of the target, reducing target utilization and increasing process costs. In addition, when the silicon wafer and the target are close together, uneven sputtering of the target can also lead to uneven film deposition.

[0005] Optimizing the magnetron structure to achieve uniform magnetic field on the target surface and improve sputtering rate and target utilization has become an urgent problem to be solved. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of the prior art and provide an orthogonal electromagnetic field rotating magnetron sputtering device.

[0007] This application provides an orthogonal electromagnetic field rotating magnetron sputtering apparatus, including a working chamber and a target material disposed within the working chamber, and further comprising: a first magnetic group disposed on one side of the working chamber, the first magnetic group comprising a plurality of permanent magnets distributed circumferentially around the working chamber; a second magnetic group disposed on the other side of the working chamber, the second magnetic group also comprising a plurality of permanent magnets distributed circumferentially around the working chamber, the first magnetic group and the second magnetic group being arranged opposite to each other about the center of the working chamber, the permanent magnets in the first magnetic group having opposite magnetic poles; and a first rotating drive mechanism for driving the first magnetic group and the second magnetic group to rotate about the center of the working chamber; wherein, the magnetic field lines of the first magnetic group and the second magnetic group are coupled below the target material to form an orthogonal magnetic field parallel to the surface of the target material, the orthogonal magnetic field enabling electrons in the magnetron sputtering process to be more effectively subjected to the Lorentz force, thereby extending the electron movement path and increasing the ionization rate of the reactant gas.

[0008] Furthermore, the permanent magnet is a neodymium iron boron permanent magnet or a samarium cobalt permanent magnet; and / or, a magnetic yoke made of a high-permeability material is provided on the side of the permanent magnet away from the center of the working cavity. The magnetic yoke can form a low magnetic resistance path, reduce magnetic circuit leakage, and guide and concentrate more magnetic lines of force to the working area below the target, thereby effectively enhancing the magnetic field strength of the working area and optimizing its distribution pattern; and / or, the orthogonal electromagnetic field rotating magnetron sputtering device also includes an electromagnetic enhancement coil, which is wound outside the working cavity. The magnetic field generated by the electromagnetic enhancement coil is in the same direction as the orthogonal magnetic field, which can enhance the magnetic field as a whole; and / or, a gap is provided between the first magnetic group and the second magnetic group. The gap is configured to prevent magnetic short circuit between the first magnetic group and the second magnetic group, thereby forcing the magnetic force to cross the working cavity and form an orthogonal magnetic field; and / or, a magnetic isolation block is provided between the first magnetic group and the second magnetic group. The magnetic permeability of the magnetic isolation block is much lower than that of the permanent magnet.

[0009] Furthermore, both the first and second magnetic groups include arc-shaped supports, with the working cavity located between the two arc-shaped supports. The arc-shaped supports can rotate around the center of the working cavity under the drive of the first rotary drive mechanism. The arc-shaped supports are provided with multiple mounting holes, each of which is used to mount a permanent magnet. The arc-shaped supports are made of non-magnetic materials. Cooling channels are provided inside the arc-shaped supports, and the cooling channels pass through all the mounting holes, allowing circulating cooling water to be introduced into the cooling channels, which can actively dissipate heat from the permanent magnets.

[0010] Furthermore, there is an angle between the central axis of the permanent magnet and the radial direction of the working cavity. The angle is configured to maximize the component of the magnetic field generated by the permanent magnet that is parallel to the target surface. The magnitude of the angle can be determined through electromagnetic simulation experiments.

[0011] Furthermore, the orthogonal electromagnetic field rotating magnetron sputtering device also includes a current-carrying conductor, which is arranged parallel to the surface of the target material and facing the central region of the target material; the current-carrying conductor is used to generate an additional magnetic field to enhance the weak region of the orthogonal magnetic field.

[0012] Furthermore, the current-carrying conductor is rotatably disposed above the target material, with its axis of rotation perpendicular to the surface of the target material; this rotation of the current-carrying conductor can homogenize the compensation effect it generates in space, thereby achieving global uniformity of the magnetic field.

[0013] Furthermore, the orthogonal electromagnetic field rotating magnetron sputtering device also includes a second rotating drive mechanism, which is used to drive the current-carrying conductor to rotate around the center of the working cavity; the rotation speed of the first magnetic group and the second magnetic group is different from the rotation speed of the current-carrying conductor, and the ratio of their speeds is not an integer; the rotation direction of the first magnetic group and the second magnetic group is opposite to the rotation direction of the current-carrying conductor.

[0014] Furthermore, the effective length of the current-carrying conductor is adjustable to adapt to different processes and achieve more comprehensive uniformity control; the effective length can be adaptively adjusted based on the current process or the consumption status of the target material.

[0015] Furthermore, the orthogonal electromagnetic field rotating magnetron sputtering device includes multiple current-carrying conductors of different lengths, which are arranged at the same point in a radially centrally symmetrical structure; in use, at least one of the current-carrying conductors can be selectively energized as needed.

[0016] Furthermore, the working chamber is equipped with a magnetic window on its cover, which is made of soft magnetic material; a current-carrying conductor is placed on the magnetic window; the magnetic window can efficiently attract and guide the external magnetic field through the cover and act on the working chamber.

[0017] This application provides an orthogonal electromagnetic field rotating magnetron sputtering apparatus, including a working chamber, a target, a first magnetic group, and a second magnetic group. Both the first and second magnetic groups include multiple permanent magnets. The first and second magnetic groups are arranged opposite to each other about the center of the working chamber, and the magnetic poles of the permanent magnets are opposite, so that the magnetic lines of force are coupled below the target to form an orthogonal magnetic field parallel to the target surface. The orthogonal magnetic field can more effectively apply the Lorentz force to the electrons and prolong the electron movement path, thereby solving the problem of low ionization rate of the reactive gas caused by the rapid bombardment or loss of electrons on the substrate, so as to improve the ionization efficiency. It also includes a first rotating drive mechanism for driving the two magnetic groups to rotate around the center of the working chamber, thereby eliminating the circumferential distribution difference of the magnetic field through the time averaging effect, solving the problem of uneven target sputtering and large film thickness deviation caused by fixed magnetic groups, and improving the target utilization rate and film deposition uniformity. Attached Figure Description

[0018] Figure 1 A schematic diagram of an orthogonal electromagnetic field rotating magnetron sputtering device provided in this application;

[0019] Figure 2 for Figure 1 A bottom view of the structure of the orthogonal electromagnetic field rotating magnetron sputtering device shown;

[0020] Figure 3 for Figure 1 A cross-sectional view of the orthogonal electromagnetic field rotating magnetron sputtering device shown;

[0021] Figure 4 for Figure 3 Enlarged view of the structure within the center circle;

[0022] Figure 5 This is a schematic diagram of a permanent magnet and a current-carrying conductor provided for this application. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] This application provides an orthogonal electromagnetic field rotating magnetron sputtering apparatus, including a working chamber 1 and a target 2 disposed within the working chamber 1, and further including: a first magnetic group 10 disposed on one side of the working chamber 1, the first magnetic group 10 including a plurality of permanent magnets distributed circumferentially along the working chamber 1; a second magnetic group 20 disposed on the other side of the working chamber 1, the second magnetic group 20 also including a plurality of permanent magnets distributed circumferentially along the working chamber 1, the first magnetic group 10 and the second magnetic group 20 being arranged opposite to each other about the center of the working chamber 1, the permanent magnets in the first magnetic group 10 having opposite magnetic poles; and a first rotating drive mechanism for driving the first magnetic group 10 and the second magnetic group 20 to rotate about the center of the working chamber 1; wherein, the magnetic lines of force of the first magnetic group 10 and the second magnetic group 20 are coupled below the target 2 to form an orthogonal magnetic field parallel to the surface of the target 2, the orthogonal magnetic field enabling electrons in the magnetron sputtering process to be more effectively subjected to the Lorentz force, thereby extending the electron movement path and increasing the ionization rate of the reactant gas.

[0025] For details, please refer to Figures 1 to 4 In the illustrated embodiment, the working chamber 1 is generally cylindrical. In actual equipment, the working chamber 1 is a closed cavity, and a stage is provided inside the working chamber 1 to support the substrate to be processed. The target material 2 is located inside the working chamber 1, at the top of the working chamber 1, with the target surface of the target material 2 facing downwards and directly opposite the stage. During magnetron sputtering, the reactive gas introduced into the working chamber 1 is ionized, and the generated plasma bombards the target material 2, causing the sputtered target atoms to deposit onto the substrate surface to achieve coating.

[0026] Continue to refer to Figure 1 and Figure 2 The first magnetic group 10 and the second magnetic group 20 are respectively located on both sides of the working cavity 1. The first magnetic group 10 includes a plurality of permanent magnets spaced apart along the arc direction, and the second magnetic group 20 also includes a plurality of permanent magnets spaced apart along the arc direction. The permanent magnets of the two groups cooperate to surround the working cavity 1.

[0027] Continue to refer to Figure 1 and Figure 3 The first magnetic group 10 and the second magnetic group 20 are located below the target material 2 and are kept at a small distance of several millimeters to 2 centimeters from the target surface to ensure that the magnetic field can effectively act on the electrons near the target surface, while reserving space for the electrons to accelerate.

[0028] Combined with reference Figure 2 and Figure 5 In each magnetic group, the permanent magnets are arranged with their magnetic poles pointing towards the center of the working cavity 1, but the magnetic poles of the permanent magnets in the two magnetic groups face opposite directions. For example, when the N pole of the permanent magnet in the first magnetic group 10 points towards the center of the working cavity 1, the S pole of the permanent magnet in the second magnetic group 20 also points towards the center of the working cavity 1; or, when the S pole of the permanent magnet in the first magnetic group 10 points towards the center of the working cavity 1, the N pole of the permanent magnet in the second magnetic group 20 also points towards the center of the working cavity 1. In this way, the magnetic field lines of the two magnetic groups can couple with each other below the target material 2, ultimately forming an orthogonal magnetic field parallel to the target surface.

[0029] It needs to be explained that, since the permanent magnets in both magnetic groups are distributed circumferentially along the working cavity 1, and when the permanent magnet poles of the first magnetic group 10 point to the working cavity 1, the permanent magnet poles of the second magnetic group 20 point in the opposite direction to the working cavity 1, the magnetic lines of force of the two magnetic groups will couple below the target material 2 (attracted by the magnetic poles of the other magnetic group and passing through the working cavity 1 to form magnetic lines of force), forming a magnetic field with the direction of the magnetic field parallel to the target surface. The magnetic lines of force generated by the permanent magnets of the first magnetic group 10 and the magnetic lines of force generated by the permanent magnets of the second magnetic group 20 intersect and superimpose in the working area below the target material 2. Since the spatial positions of the two magnetic groups are symmetrical and the magnetic poles are opposite, the superimposed magnetic lines of force form mutually perpendicular components in a plane parallel to the surface of the target material 2, namely radial components and tangential components. These two perpendicular components together constitute an orthogonal magnetic field parallel to the target surface.

[0030] The orthogonal magnetic field is perpendicular to the initial motion direction of the electron (perpendicular to the target surface) and the electric field direction (perpendicular to the target surface, with the target material being the cathode and the substrate being the anode) at 90°, satisfying the orthogonal condition for maximizing the Lorentz force (Lorentz force F=qvBsinθ, sinθ=1 when θ=90°, F is the maximum).

[0031] Specifically, the initial direction of electron motion is perpendicular to the target surface (accelerated by the electric field), while the magnetic field formed by the orthogonal magnetic field is parallel to the target surface, with an angle of 90° between them. At this point, the Lorentz force on the electron is at its maximum, which can force the electron to deviate from its straight trajectory and move along a cycloidal path. The increased length of the electron's motion path increases the probability of collisions between the electron and the reactive gas (such as argon), and the efficiency of ionization of gas atoms and generation of positive ions also increases exponentially, so as to form a high-density plasma region (i.e., the working area) below the target material 2, laying the foundation for efficient sputtering.

[0032] The first rotary drive mechanism can be any drive component capable of driving the first magnetic group 10 and the second magnetic group 20 to rotate, such as a rotary cylinder or a motor.

[0033] To ensure the stability of the orthogonal magnetic field itself, the first magnetic group 10 and the second magnetic group 20 need to rotate synchronously. Therefore, two sets of first rotation drive mechanisms can be set so that the first magnetic group 10 and the second magnetic group 20 can rotate independently and in coordination. Alternatively, only one set of first rotation drive mechanisms can be set to drive the first magnetic group 10 and the second magnetic group 20 to rotate synchronously, thereby ensuring that the orthogonal magnetic field formed by coupling can circumferentially cover the working area below the target material 2.

[0034] In one embodiment, the first rotary drive mechanism adopts a synchronous belt drive. The drive motor of the first rotary drive mechanism is connected to the driving pulley, and the driven pulley (fixedly connected to the magnetic group) is provided on the outside of the working chamber 1. The driving pulley drives the driven pulley to rotate through the synchronous belt, thereby realizing the synchronous rotation of the dual magnetic groups under single drive.

[0035] In another embodiment, the first rotary drive mechanism adopts a torque motor. The output shaft of the motor is directly connected to the common bracket of the first magnetic group 10 and the second magnetic group 20 (the common bracket is used to install the two magnetic groups and can extend to the straight line where the central axis / rotation axis is located so as to connect with the motor and realize the rotation of the magnetic group around the cavity). The drive shaft of the motor is collinear with the central axis of the working cavity 1, and the motor can directly drive the two magnetic groups to rotate around the center.

[0036] In another embodiment, the first rotary drive mechanism includes a drive motor 31, a drive gear 32, and a driven gear 33. The drive motor 31 is used to rotate the drive gear 32, and the drive gear 32 meshes with the driven gear 33. The driven gear 33 is arranged in a ring shape and rotatably surrounds the working cavity 1. The first magnetic group 10 and the second magnetic group 20 are fixedly arranged on the driven gear 33.

[0037] For details, please refer to Figure 1 and Figure 3 In the illustrated embodiment, the top of the working chamber 1 is provided with a chamber cover 1a, which has a large planar dimension and an exposed skirt. The drive motor 31 is fixed to the bottom surface of the exposed skirt of the chamber cover 1a, and a drive gear 32 is provided on the output shaft. The driven gear 33 is arranged in a ring shape and is sleeved on the outside of the working chamber 1, with the axis of the driven gear 33 coinciding with the axis of the working chamber 1; the first magnetic group 10 and the second magnetic group 20 are provided on the bottom surface of the driven gear 33.

[0038] Combined with reference Figure 4 The exposed bottom surface of the skirt of the cavity cover 1a is also provided with an annular guide groove, the cross-section of which is T-shaped. The top surface of the driven gear 33 is provided with a T-shaped slider, which is slidably positioned in the annular guide groove (rollers, balls, or other structures can be added to the annular guide groove to reduce friction and enhance sliding performance). The driven gear 33 is suspended below the skirt and can rotate around the center of the working cavity 1 along the annular guide groove.

[0039] Continue to refer to Figure 1 and Figure 3 The driving gear 32 meshes with the driven gear 33. During operation, the drive motor 31 drives the driving gear 32 to rotate, and the driving gear 32 meshes with and drives the driven gear 33 to rotate around the working cavity 1. The driven gear 33 is radially offset by the annular guide groove, which drives the double magnetic group to rotate around the working cavity 1.

[0040] Through gear transmission, it can be ensured that the first magnetic group 10 and the second magnetic group 20 rotate in the same direction and at the same speed, without relative motion deviation, thus avoiding the disturbance of the orthogonal magnetic field caused by the different rotation speeds of the two magnetic groups and ensuring the stability of the magnetic field distribution below the target material 2.

[0041] When the dual magnetic groups are stationary, there may be local magnetic field strength differences in the orthogonal magnetic fields (the etching degree is high near the magnetic pole and low far from the magnetic pole). This causes the dual magnetic groups to rotate with the passive gear 33, which can average the instantaneous non-uniformity of the magnetic field on the time axis, and finally form a uniform etching ring on the surface of the target material 2. This avoids the annular etching track caused by the traditional fixed magnetic group and effectively improves the utilization rate of the target material.

[0042] In one specific embodiment, Ti thin films are prepared by Ti target sputtering, and the specific workflow is as follows:

[0043] Target material 2 is a Ti target (thickness 8mm, diameter 300mm).

[0044] A silicon substrate (anode) is placed at the bottom of the working chamber 1, and the target material 2 is connected to a DC negative high voltage (cathode) to form an electric field perpendicular to the target surface (the direction of the electric field is from the substrate to the target material).

[0045] Vacuuming of working chamber 1 (10 -4 ~10 -5 After Pa), argon gas (reaction gas) is introduced to the working pressure (0.5~2 Pa).

[0046] The N pole of the first magnetic group 10 faces the center of the working cavity 1, and the S pole of the second magnetic group 20 faces the center of the working cavity 1. The dual magnetic groups are located 1 cm below the target material 2.

[0047] The first rotary drive mechanism drives the double magnetic group to rotate around the center of the working chamber 1 at a speed of 100 rpm.

[0048] After being powered on, an electric field is formed between the target 2 and the substrate. Electrons are emitted from the surface of the target 2 and accelerated by the electric field. They move in an initial direction perpendicular to the target surface (pointing into the working cavity 1). They first pass through the weak magnetic field region between the target 2 and the magnetic group to complete the acceleration (run-up).

[0049] After an electron enters the orthogonal magnetic field parallel to the target surface formed by the coupling of two magnetic groups, it experiences the maximum Lorentz force because the direction of electron motion is perpendicular to the direction of the magnetic field, and its trajectory becomes a cycloidal spiral path.

[0050] The extended electron path increases the collision ionization rate between electrons and argon atoms, resulting in a high-density Ar atom formation below target 2. + Plasma region;

[0051] Ar + The surface of the target 2 is sputtered and detached from the target 2 by the accelerated bombardment of the electric field, and then deposited downwards onto the surface of the silicon substrate.

[0052] The dual magnetic array rotates continuously, ensuring that all areas of the target material 2 surface are bombarded evenly, thus avoiding excessive local sputtering.

[0053] The orthogonal electromagnetic field rotating magnetron sputtering device provided in this application sets up a first magnetic group 10 and a second magnetic group 20, with the two magnetic groups being relatively distributed about the center of the working cavity 1 and the permanent magnets having opposite magnetic poles. This couples the magnetic lines of force below the target material 2 to form an orthogonal magnetic field parallel to the target surface. The orthogonal magnetic field can more effectively apply the Lorentz force to the electrons, extending the electron movement path, thereby solving the problem of low ionization rate of the reactive gas caused by the rapid bombardment or loss of electrons on the substrate, so as to improve the ionization efficiency. Combined with the first rotating drive mechanism driving the two magnetic groups to rotate around the center of the working cavity 1, the time averaging effect can eliminate the circumferential distribution difference of the magnetic field, solving the problem of uneven target sputtering and large film thickness deviation caused by the fixed magnetic group, so as to improve the target utilization rate and film deposition uniformity.

[0054] Optionally, the permanent magnet is a neodymium iron boron permanent magnet or a samarium cobalt permanent magnet.

[0055] Neodymium iron boron permanent magnets and samarium cobalt permanent magnets are both high energy product permanent magnet materials. They can provide a sufficiently strong magnetic field (magnetic induction intensity can reach 0.3-0.8T) within an optimal distance of several millimeters to 2 centimeters below the target material 2, which meets the magnetic field strength requirements for electron cyclotron acceleration and high-density plasma formation, and avoids the decrease in ionization efficiency due to an insufficiently weak magnetic field.

[0056] In addition, neodymium iron boron permanent magnets have a coercivity of 800-2000 kA / m, and samarium cobalt permanent magnets have a coercivity of 600-1500 kA / m. Both can maintain stable magnetic properties under rotational vibration, avoiding magnetic field attenuation that leads to a deterioration in the orthogonal magnetic field coupling effect, and ensuring long-term process consistency.

[0057] Optionally, a magnetic yoke made of a high-permeability material is provided on the side of the permanent magnet away from the center of the working cavity 1. The magnetic yoke can form a low magnetic resistance path, reduce magnetic circuit leakage, and guide and concentrate more magnetic lines of force to the working area below the target material 2, thereby effectively enhancing the magnetic field strength of the working area and optimizing its distribution.

[0058] The magnetic yoke is a magnetically conductive structure made of a high-permeability material, located on the side of the permanent magnet away from the center of the working cavity 1. Its essence is a low-resistivity magnetic field line guiding carrier.

[0059] Under normal conditions, some magnetic field lines of the permanent magnet will diffuse outwards away from the center of the working cavity 1 (i.e., magnetic circuit leakage), which will lead to a decrease in the magnetic field line density in the working area below the target material 2. Since the magnetic field lines of the permanent magnet have the characteristic of closing along a low magnetic reluctance path, the magnetic yoke can provide a shortcut for the magnetic field lines on the outside of the permanent magnet through its excellent magnetic permeability. This allows the magnetic field lines that might otherwise leak to be conducted along the magnetic yoke instead of diffusing into the air, thereby changing the natural distribution trajectory of the magnetic field lines, preventing the magnetic field lines from diffusing into the non-working area, and ensuring that more magnetic field lines participate in the coupling of the orthogonal magnetic field.

[0060] The magnetic yoke is made of high-permeability materials, such as industrial pure iron (e.g., DT4 electrical pure iron), silicon steel sheets, or permalloy. These materials can achieve a permeability of up to 10⁻⁶. 4 -10 5 With a magnetic permeability of H / m, which is much higher than that of air, magnetic circuit resistance can be minimized and magnetic line losses can be reduced.

[0061] The magnetic yoke can be set into any form, such as a plate or sheet, to conveniently fit the permanent magnet away from the center of the working cavity 1.

[0062] In one embodiment, the first magnetic group 10 and the second magnetic group 20 further include an arc-shaped bracket, and the permanent magnet is embedded in the mounting hole of the arc-shaped bracket; the magnetic yoke is set in the form of an arc-shaped thin plate, the shape of which is adapted to the back side of the arc-shaped bracket away from the center of the working cavity 1; the magnetic yoke is also provided with a groove that matches the end of the permanent magnet; after the permanent magnet is installed in place, the magnetic yoke is fixed on the arc-shaped bracket, and it is ensured that the end of each permanent magnet away from the center of the working cavity 1 can be in close contact with the magnetic yoke, so as to realize the efficient transmission of magnetic lines of force.

[0063] The magnetic yoke is attached to the outer side of the permanent magnet, and through magnetic guidance, it guides the magnetic field lines of the permanent magnet from their natural divergence state to the orthogonal magnetic field coupling region below the target material 2, thereby increasing the magnetic field line density in the working area and enhancing the magnetic induction intensity of the orthogonal magnetic field. Furthermore, through its overall magnetic guidance, the magnetic yoke allows the magnetic field lines of adjacent permanent magnets to "connect" within the yoke and then be uniformly guided to the working area, thus eliminating weak magnetic field areas and making the orthogonal magnetic field distribution more uniform along the circumference below the target material 2, further improving target utilization and thin film deposition uniformity.

[0064] Optionally, the orthogonal electromagnetic field rotating magnetron sputtering device also includes an electromagnetic enhancement coil, which is wound around the outside of the working cavity 1. The direction of the magnetic field generated by the electromagnetic enhancement coil is consistent with the direction of the orthogonal magnetic field, which can enhance the magnetic field as a whole.

[0065] The coil can be wound between the permanent magnet and the working cavity 1, or it can be wound on the permanent magnet. The coil can rotate with the magnetic assembly, or it can remain stationary relative to the working cavity 1.

[0066] In one embodiment, the first magnetic group 10 and the second magnetic group 20 further include an arc-shaped bracket, and the permanent magnet is embedded in the mounting hole of the arc-shaped bracket. The coil is wound on the arc-shaped bracket.

[0067] When the coil is energized, it generates a magnetic field. This magnetic field, combined with the orthogonal magnetic field, increases the magnetic induction intensity in the working area below the target 2, further strengthening the Lorentz force's confinement effect on electrons and improving the ionization rate of the reactant gas. Furthermore, providing a constant compensation current to the coil can counteract inherent static magnetic field interference within the working cavity 1 (such as stray magnetic fields generated by the cavity wall metal structure), preventing static errors from affecting the stability of the orthogonal magnetic field and ensuring long-term process consistency.

[0068] In one specific embodiment, the first magnetic group 10 and the second magnetic group 20 further include an arc-shaped support and a magnetic yoke. The magnetic yoke is arranged in an arc-shaped thin sheet adapted to the back of the arc-shaped support. After the permanent magnet is installed in place, the magnetic yoke is attached to the end face of the permanent magnet away from the center of the working cavity 1. The electromagnetic enhancement coil is made of high-temperature resistant polyimide-coated copper wire and includes two independent arc-shaped multi-turn solenoid coil units. The first coil unit is wound around the first magnetic yoke (set on the first magnetic group 10), and the second coil unit is wound around the second magnetic yoke (set on the second magnetic group 20). The curvature of the coil unit is adapted to the arc distribution of the magnetic yoke. The electromagnetic enhancement coil is also equipped with a closed-loop control module, including a PLC control unit and a Hall effect magnetic field sensor. The magnetic field sensor is embedded in the inner wall of the working cavity 1 and faces the working area below the target material 2. It can collect magnetic field intensity distribution data in real time. The control unit is electrically connected to the two coil units and the magnetic field sensor respectively. The control unit has a preset model of uniform two-dimensional magnetic field distribution on the surface of the target material 2.

[0069] During operation, the first magnetic group 10 and the second magnetic group 20 are coupled below the target material 2 to form an orthogonal magnetic field parallel to the target surface; the control unit passes a clockwise current to the first coil unit and a counterclockwise current to the second coil unit, so that the magnetic fields generated by the two coil units converge below the target material 2 into a magnetic field in the same direction as the orthogonal magnetic field, thereby achieving superposition and enhancement of the magnetic field.

[0070] The magnetic field sensor collects magnetic field distribution data below the target material 2 every 10ms. If the magnetic field strength in the edge region of the target material 2 is detected to be lower than the preset model (e.g., preset 0.4T, actual only 0.35T), the control unit immediately increases the current of the corresponding coil unit until the magnetic field in that region meets the standard. If the stray magnetic field generated by the metal structure of the inner wall of the working cavity 1 causes the magnetic field in the center region of the target material to be too high, the control unit supplies a constant compensation current of -0.2A to the coil to cancel out static magnetic field interference.

[0071] The yoke and coil unit can continuously provide a directional enhanced magnetic field to the rotating first magnetic group 10 and the second magnetic group 20. At the same time, the control unit can combine the rotation speed signal of the rotation drive mechanism to fine-tune the coil current in advance, realize predictive magnetic field compensation, and avoid magnetic field fluctuations caused by the rotation of the magnetic group.

[0072] The strong magnetic field structure formed by the magnetic yoke and coil can effectively increase the magnetic induction intensity in the working area below the target 2, further enhancing the confinement effect of the Lorentz force on electrons and increasing the ionization rate of the reactant gas. It ensures that the magnetic field distribution on the surface of the target 2 conforms to the preset model of two-dimensional uniform distribution, and the magnetic field strength deviation is controlled within ±2%. It can also effectively solve the problem of magnetic field inhomogeneity caused by magnetic group rotation and static interference in traditional structures.

[0073] Optionally, a gap is provided between the first magnetic group 10 and the second magnetic group 20. The gap is configured to prevent a magnetic short circuit between the first magnetic group 10 and the second magnetic group 20, thereby forcing the magnetic force to cross the working cavity 1 and forming an orthogonal magnetic field.

[0074] Since the permanent magnets of the first magnetic group 10 and the second magnetic group 20 are configured with opposite polarities, if the two magnetic groups are directly close to each other without any gap, the magnetic field lines will follow the characteristic of closing along the path of least magnetic reluctance, preferentially connecting from the N pole of the first magnetic group directly to the S pole of the adjacent second magnetic group via a short path, forming a magnetic short circuit that is ineffective inside the working cavity 1. In this case, most of the magnetic flux will be consumed in the short circuit between the two magnetic groups and cannot be emitted into the working cavity 1, resulting in a decrease in the effective magnetic field strength below the target material 2 used to confine electrons and excite plasma.

[0075] Setting intervals can break this short-path magnetic circuit, forcing magnetic lines of force to take a longer route—after originating from the N pole of the first magnetic group, they must cross the space inside the working cavity 1 to reach the S pole of the second magnetic group, thereby forming a closed magnetic field loop that runs through the working cavity 1 and is roughly parallel to the surface of the target material 2.

[0076] The spacing needs to be determined by combining the magnet's own parameters with magnetic field simulation optimization. There are two basic reference dimensions: first, the spacing must be at least equivalent to the height of the magnet to ensure that short-path magnetic circuits are physically blocked; second, the spacing should be 1.5-2 times the width of the magnet's projection on the target material 2 surface to avoid the risk of localized magnetic short circuits due to an insufficient spacing. The final precise dimensions need to be determined through parametric scanning using electromagnetic field simulation software (such as COMSOL). After simulating key indicators such as magnetic field strength and uniformity under different spacing sizes below the target material 2, the spacing value that ensures the orthogonal magnetic field strength meets the standard (e.g., magnetic induction intensity ≥ 0.3T) and has the most uniform distribution is selected to ensure that the magnetic field can stably confine electrons and efficiently excite plasma.

[0077] Optionally, a magnetic isolation block is provided between the first magnetic group 10 and the second magnetic group 20, and the magnetic permeability of the magnetic isolation block is much lower than that of the permanent magnet.

[0078] Magnetic blocks can be made of aluminum alloy or austenitic stainless steel. The magnetic permeability of these materials is much lower than that of permanent magnets, and they belong to high magnetic resistance materials.

[0079] The grid of magnetic blocks serves two purposes. First, their high magnetoresistance characteristics can block magnetic short-circuit paths, thereby forcing more magnetic lines of force to cross the working cavity 1 (starting from the magnetic poles of the first magnetic group 10, passing through the working area below the target material 2, and then reaching the opposite magnetic poles of the second magnetic group 20), ensuring that the effective magnetic flux of the orthogonal magnetic field is concentrated in the working area. Second, it can regulate the magnetic circuit direction, reduce the interference of magnetic leakage on the magnetic field distribution, and keep the orthogonal magnetic field parallel to the target surface in a stable state below the target material 2, further ensuring the stability of electrons under the Lorentz force and improving plasma density and sputtering uniformity.

[0080] To facilitate the placement of permanent magnets, both the first magnetic group 10 and the second magnetic group 20 include arc-shaped supports. The working cavity 1 is located between the two arc-shaped supports. The arc-shaped supports can rotate around the center of the working cavity 1 under the drive of the first rotary drive mechanism. The arc-shaped supports are provided with multiple mounting holes, and any mounting hole is used to place a permanent magnet.

[0081] For details, please refer to Figure 1 or Figure 3 In the illustrated embodiment, the arc-shaped support extends arc-shaped along the outer wall of the working cavity 1, forming an overall arc-shaped plate structure that conforms to the contour of the working cavity 1. A gap exists between the arc-shaped support and the working cavity 1 to allow for rotation. Two arc-shaped supports are arranged radially opposite to each other along the working cavity 1, fitting together to encircle the working cavity 1 between them. The arc-shaped support is positioned below the target material 2, maintaining an optimal distance of several millimeters to 2 centimeters from the target surface.

[0082] Continue to refer to Figure 1 or Figure 3 The arc-shaped bracket has multiple mounting holes, which are evenly spaced along the extended square of the arc-shaped bracket. The diameter of the mounting holes is adapted to the outer diameter of the permanent magnet, ensuring that each permanent magnet can be firmly embedded in the mounting hole (direct interference fit, or positioning components such as baffles, or reinforcement with glue). The magnetic pole direction of the permanent magnet (pointing into the working cavity 1) can be accurately positioned by the orientation of the mounting holes.

[0083] The mounting holes spaced circumferentially allow for precise positioning and secure fixing of the permanent magnets, ensuring that the permanent magnets of the first magnetic group 10 and the second magnetic group 20 are reliably distributed circumferentially along the working cavity 1, and that the magnetic poles uniformly point towards the working cavity 1, providing a basic arrangement condition for the coupling of orthogonal magnetic fields.

[0084] Alternatively, the curved support can be made of a non-magnetic material.

[0085] Specifically, the arc-shaped support is made of non-magnetic materials with low magnetic permeability and high strength, such as aluminum alloy (preferably 6061 series or 7075 series aluminum alloy) and austenitic stainless steel (preferably 304 series or 316 series austenitic stainless steel).

[0086] As the carrier of the permanent magnet, the arc-shaped support must ensure that the magnetic flux emitted by the permanent magnet can efficiently enter the working cavity 1 to form a stable orthogonal magnetic field. The selected non-magnetic materials, such as aluminum alloy and austenitic stainless steel, will not shunt the magnetic lines of force of the permanent magnet, which is conducive to the lossless passage of magnetic lines of force through the arc-shaped support and direct guidance to the working area below the target material 2, avoiding magnetic flux leakage or attenuation due to the magnetic conduction of the arc-shaped support.

[0087] In addition, aluminum alloys and austenitic stainless steels have excellent mechanical strength, which can maintain structural rigidity during long-term rotation and prevent the permanent magnet from shifting due to the deformation of the arc support. At the same time, the low material density of aluminum alloys and austenitic stainless steels can also reduce the load and inertia of the rotary drive, making the start and stop of the rotary drive smoother and the speed adjustment more flexible.

[0088] Optionally, the arc-shaped bracket is provided with cooling channels, which pass through all the mounting holes and allow circulating cooling water to flow into the cooling channels, enabling active heat dissipation for the permanent magnet.

[0089] The permanent magnet is located near the working chamber 1 and will heat up due to the high temperature inside the chamber. If the temperature exceeds the maximum tolerance temperature of the permanent magnet (e.g., the tolerance temperature of neodymium iron boron permanent magnets is usually ≤150℃, and that of samarium cobalt permanent magnets is ≤300℃), it will cause irreversible decay of its magnetic properties, manifested as a decrease in magnetic induction intensity and disordered magnetic field distribution, ultimately affecting the sputtering efficiency and process stability of the device.

[0090] Cooling channels are installed inside the arc-shaped support, and circulating cooling water (temperature controlled at 20-30℃) is introduced into these channels. As the water flows through the channel walls, it exchanges heat with the permanent magnet, carrying away the heat absorbed by the magnet in real time, thus keeping the magnet's temperature stably controlled below its tolerance level. This effectively prevents irreversible decay of magnetic properties and maintains long-term stability in the magnetic field strength and distribution.

[0091] Specifically, the cooling channels are integrated inside the arc-shaped bracket, and the overall design is highly compatible with the bracket structure and the positions of the permanent magnet mounting holes. The cooling channels can adopt a serpentine, meandering structure, extending along the arc-shaped contour of the bracket, and the channels pass through all the mounting holes of the permanent magnets (starting from one end of the bracket, sequentially encircling the outer periphery of each mounting hole, and finally leading out from the other end of the bracket), ensuring that each permanent magnet is covered by the channels, with no blind spots in heat dissipation.

[0092] More specifically, an extended metal interface is provided at the water inlet and outlet of the arc-shaped bracket, and a closed cooling loop can be formed by connecting the interface with an external circulating cooling water system (including water pump, cooling tower, and thermostat) through a hose.

[0093] A stable magnetic field is fundamental for the effective confinement of electrons and the enhancement of plasma density by orthogonal magnetic fields. Cooling channels help maintain the magnetic properties of permanent magnets, ensuring that the strength of the orthogonal magnetic field beneath the target 2 always meets process requirements. This, in turn, guarantees the stability of electron movement paths and the ionization rate of reactive gases, avoiding problems such as sputtering rate variations and uneven film thickness caused by magnetic field fluctuations. Active heat dissipation also reduces aging losses of permanent magnets due to high temperatures, extending their replacement cycle. Simultaneously, cooling channels lower the temperature of the arc-shaped support, preventing deformation due to prolonged high temperatures.

[0094] Optionally, the arc-shaped support is provided with hollowed-out or weight-reducing grooves, and the cooling channels and weight-reducing structures are staggered.

[0095] By reducing the weight of the structure, the load and inertia of the first rotary drive mechanism can also be reduced, making the rotation of the arc-shaped support and the magnetic assembly easier, the start and stop smoother, and the speed adjustment more flexible.

[0096] In one embodiment, there is an angle between the central axis of the permanent magnet and the radial direction of the working cavity 1, and the angle is configured to maximize the component of the magnetic field generated by the permanent magnet that is parallel to the surface of the target material 2.

[0097] The magnetic field generated by the permanent magnet in its natural state is a spatial vector, which can be decomposed into a radial component (pointing towards / away from the center of the working cavity 1 and parallel to the target surface), an axial component (parallel to the axis of the working cavity 1 and perpendicular to the target surface), and a tangential component (along the circumferential tangent of the working cavity 1 and parallel to the target surface). The axial component is ineffective or even detrimental to electron confinement because it cannot form an angle with the initial direction of electron motion perpendicular to the target surface. This not only fails to enhance the Lorentz force but also interferes with the cycloidal trajectory of the electrons, causing them to prematurely leave the plasma region and reducing the ionization efficiency of the reactive gas. The radial and tangential components parallel to the target surface are the components required in this application to maximize the Lorentz force.

[0098] By designing the tilt angle, the component ratio of the magnetic field vector can be adjusted, weakening the harmful axial component while enhancing the beneficial parallel component (i.e., radial and tangential components), thus avoiding the magnetic field vector imbalance from affecting the constraint effect of the orthogonal magnetic field.

[0099] Specifically, the tilt angle design follows the principle of symmetrical reverse tilting. The core is to cancel the axial component and superimpose the parallel component through the reverse tilt angles of the first magnetic group 10 and the second magnetic group 20. The specific steps are as follows:

[0100] The N pole of the first magnetic group points towards the center of the cavity. It is necessary to press down its N pole and raise its S pole to form an "inner low and outer high" posture, so that the magnetic field deflects obliquely downward (↙) and generates a downward axial component.

[0101] The S pole of the second magnetic group points towards the center of the cavity. It is necessary to raise its S pole and lower its N pole to form an "inner high and outer low" posture, so that the magnetic field deflects obliquely upward (↗) and generates an upward axial component.

[0102] Through this symmetrical and reverse design, the axial components of the two sets of magnets are equal in magnitude and opposite in direction, thus completely canceling each other out.

[0103] By symmetrically tilting in opposite directions, the downward axial component of the first magnetic group 10 completely cancels out the upward axial component of the second magnetic group 20. The total axial magnetic field component below the target material is close to zero, effectively eliminating its interference with electron motion and ensuring that electrons are only constrained by the magnetic field parallel to the target surface. At the same time, the tilt angle adjustment allows the magnetic field vector of the permanent magnet to be distributed more radially and tangentially, making the angle between the electron and the magnetic field closer to 90°, which is beneficial for maximizing the Lorentz force.

[0104] The tilt angle can be determined through electromagnetic simulation experiments, and the specific steps are as follows:

[0105] Using professional electromagnetic simulation software, such as COMSOL Multiphysics and ANSYS HFSS, a model was constructed based on the actual dimensions and parameters of the device. The geometry of the working cavity 1, target material 2, first magnetic group 10, second magnetic group 20, and arc-shaped support was accurately drawn. The material properties of the permanent magnets (such as the remanence and coercivity parameters of neodymium iron boron permanent magnets) were set, and the relative positional relationships between the components were defined to ensure that the model closely matches the actual device.

[0106] Set electromagnetic parameters consistent with actual working conditions, including electric field strength and initial electron velocity. Establish appropriate boundary conditions based on the device's operating environment, such as setting the working cavity wall as an electrically insulating boundary and target 2 as a grounded boundary. Determine the incident direction and polarization of the plane wave source to simulate the motion of electrons and the interaction of the magnetic field during magnetron sputtering.

[0107] The tilt angle of the permanent magnet is set as a variable, and the scanning range is determined based on experience or preliminary estimation. Generally, multiple discrete values ​​can be selected between 0° and 30°, such as 5°, 10°, 15°, 20°, 25°, etc. The tilt angle variable is set separately for the permanent magnets of each magnetic group to ensure that the tilt angle changes of the first magnetic group 10 and the second magnetic group 20 conform to the principle of symmetrical reverse tilting, so as to counteract the harmful axial magnetic field component.

[0108] Electromagnetic simulation experiments were run for each tilt angle combination. During the simulation, the focus was on collecting relevant data on the magnetic field near the surface of target 2, including key parameters such as magnetic field strength, magnetic field direction (axial component, radial component, and tangential component), electron trajectory in the magnetic field, and ionization rate. These data were then extracted and processed using the software's post-processing function.

[0109] The collected data were analyzed with the goal of minimizing the axial magnetic field component, maximizing the parallel component, and achieving the highest electron ionization rate. Magnetic field component data at different tilt angles were compared to identify the combination where the axial component is close to zero and the parallel component is maximized. Simultaneously, electron ionization rate data was used to verify whether the sputtering effect under this tilt angle combination was optimal. If multiple similar optimized combinations emerged, factors such as device stability and manufacturing difficulty needed to be comprehensively considered to ultimately determine the optimal tilt angle.

[0110] In actual equipment, after determining the specific tilt angle, a special arc-shaped bracket can be configured to provide a tilted positioning surface that matches the tilt angle in the mounting hole of the arc-shaped bracket. The tilted positioning surface is used to enable the embedded permanent magnet to have and maintain the designed tilt angle.

[0111] Optionally, the orthogonal electromagnetic field rotating magnetron sputtering apparatus provided in this application further includes a current-carrying conductor 3, which is arranged parallel to the surface of the target material 2 and faces the central region of the target material 2; the current-carrying conductor 3 is used to generate an additional magnetic field to enhance the weak region of the orthogonal magnetic field.

[0112] The current-carrying conductor 3 is a metallic conductor that has electrical conductivity and can generate an additional magnetic field through current.

[0113] In one embodiment, the current-carrying conductor 3 is a single straight conductor made of a highly conductive metal material (such as pure copper, oxygen-free copper, or copper-silver alloy), and its length does not exceed 1 / 3 of the diameter of the target material 2 (such as a 40mm long conductor for a 300mm diameter target material), ensuring that the current-carrying conductor 3 can completely cover the central area of ​​the target material 2 and does not exceed the range of the target material 2.

[0114] In another embodiment, the current-carrying conductor 3 is made of high-purity copper material (purity ≥99.95% oxygen-free copper), and has an overall hollow tubular structure, through which circulating cooling water can flow.

[0115] Specifically, the hollow tube of the current-carrying conductor 3 has an outer diameter of 4mm, an inner diameter of 2mm, and a length of 35mm (suitable for a target material with a diameter of 300mm); the axis of the current-carrying conductor 3 is parallel to the surface of the target material 2, and the distance between the current-carrying conductor 3 and the target material 2 is kept at 8mm. This distance is determined by electromagnetic field simulation, which can make the axial additional magnetic field generated by the conductor accurately cover the central weak area of ​​the target material 2.

[0116] Furthermore, the two ends of the current-carrying conductor 3 are equipped with insulating ceramic joints. The two insulating ceramic joints are respectively integrated with copper water inlet and water outlet interfaces. The water inlet interface is connected to a micro circulating water pump through a high-pressure resistant hose, and the water outlet interface is connected to a cooling medium storage tank to form a closed cooling circuit. The cooling medium is deionized water to avoid affecting the magnetic field of the conductor due to the conductivity of the medium.

[0117] In use, the temperature of the deionized water in the cooling medium storage tank is first stabilized at 22℃ by the temperature control module. Then, the micro circulating water pump is started, allowing the deionized water to flow into the current-carrying conductor 3 from the inlet at a flow rate of 1.2L / min. After flowing through the entire current-carrying conductor 3, it flows back to the cooling medium storage tank from the outlet. Through heat exchange between the water flow and the tube wall of the current-carrying conductor 3, the heat generated by the current-carrying conductor 3 due to energization and plasma radiation is carried away. At the same time, a 2.5A DC current is introduced into the current-carrying conductor 3, which generates an axial additional magnetic field. This magnetic field vector is superimposed with the orthogonal magnetic field vectors formed by coupling with the first magnetic group 10 and the second magnetic group 20, which can enhance the magnetic field strength in the central region of the target material 2 and effectively reinforce the central weak area.

[0118] The cooling system, which consists of a closed cooling loop, can keep the operating temperature of the current-carrying conductor 3 stable below 45°C, avoiding the increase in resistance and instability of the magnetic field caused by high temperature. At the same time, the copper hollow structure takes into account both conductivity and cooling adaptability, which can ensure the long-term stability of the additional magnetic field.

[0119] To facilitate power connection, the current-carrying conductor 3 is horizontally suspended on the cavity cover 1a of the working cavity 1 and located directly above the center of the target material 2, ensuring that the axis of the current-carrying conductor 3 is parallel to the surface of the target material 2, and the distance between the current-carrying conductor 3 and the surface of the target material 2 is controlled at 5-15mm (the specific distance can be determined by electromagnetic field simulation to avoid the conductor being bombarded by plasma if the distance is too close, or the additional magnetic field being weakened if the distance is too far).

[0120] The conductor 3 is powered by an external DC power supply (such as an adjustable constant current power supply), and the current magnitude is adjusted according to the strength requirements of the weak region of the orthogonal magnetic field (usually 1-5A). Combining the Biot-Savart law, the direction of the additional magnetic field is controlled by changing the direction of the current; for example, when the radial component of the orthogonal magnetic field in the central region of the target 2 is weak, a clockwise current is applied (viewed from the top of the cavity cover 1a), so that the axial additional magnetic field generated by the conductor and the radial component of the orthogonal magnetic field form a vector superposition, thereby specifically enhancing the magnetic field in the central weak region.

[0121] The orthogonal magnetic field is formed by the coupling of the first magnetic group 10 and the second magnetic group 20. Due to the influence of the magnetic group arrangement, the central region of the target material 2 is prone to a weak magnetic field area (insufficient radial component). The axial additional magnetic field generated by the current-carrying conductor 3 can be vector-superimposed with the radial component of the orthogonal magnetic field. By controlling the direction and magnitude of the current, the total magnetic field strength in the central region of the target material 2 can be effectively improved, the uneven distribution of the magnetic field can be eliminated, and the problem of low central sputtering rate caused by weak central magnetic field can be avoided.

[0122] By adjusting the current in the conductor 3, the strength and coverage of the additional magnetic field can be flexibly adjusted to adapt to sputtering processes of different target materials (such as Ti target, Al target) and different substrate sizes (such as 200mm and 300mm substrates). For example, when sputtering a large-diameter target 2, the current is increased to expand the reinforcement range of the additional magnetic field, ensuring the overall magnetic field uniformity of the target 2 and avoiding the need to readjust the magnetic assembly structure due to process changes.

[0123] Optionally, the current-carrying conductor 3 is rotatably disposed above the target material 2, with its axis of rotation perpendicular to the surface of the target material 2; such that the rotation of the current-carrying conductor 3 can homogenize the compensation effect it generates in space, so as to achieve global uniformity of the magnetic field.

[0124] Specifically, an installation groove is made on the top surface of the cavity cover 1a at the position corresponding to the center of the target material 2. A ceramic insulated bearing is embedded in the groove (to prevent conductivity). One end of the insulated rotating shaft passes through the bearing and is rotatably connected to the cavity cover 1a, while the other end is connected to a rotary drive (such as a micro stepper motor or servo motor) located above the cavity cover 1a. The current-carrying conductor 3 is mounted on the insulated rotating shaft. In this way, the rotary drive can drive the current-carrying conductor 3 to rotate at the center position.

[0125] It should be explained that when the current-carrying conductor 3 is fixed, the additional magnetic field it generates only forms compensation in a local area directly opposite the center of the target material 2. Due to the fixed position of the current-carrying conductor 3, local compensation is easily excessive while peripheral compensation is insufficient, making it impossible to achieve global uniformity of the magnetic field on the target surface.

[0126] By rotating the current-carrying conductor 3, the axial additional magnetic field it generates changes with the position of the current-carrying conductor 3, and periodically sweeps across the 360° range of the central region of the target material 2. This transforms the local compensation during fixation into circumferential dynamic compensation, enabling each region in the central part of the target material 2 to obtain uniform magnetic field reinforcement during the process cycle. Ultimately, this eliminates the circumferential differences in the magnetic field distribution, achieves global magnetic field uniformity, and avoids sputtering rate differences or film thickness deviations in the central region of the target material 2 caused by local magnetic field inhomogeneity.

[0127] Optionally, the current-carrying conductor 3 rotates at a uniform speed, in one direction, or at a medium to low speed.

[0128] By keeping the rotation speed of the current-carrying conductor 3 constant (e.g., 80 rpm), the uneven time that the additional magnetic field sweeps across the target surface due to rotation speed fluctuations can be avoided, ensuring that the central area of ​​the target 2 obtains the same compensation time within the process cycle, thus forming a stable and predictable average compensation effect.

[0129] The rotation speed should be selected to match the process cycle, and is usually set to 50-200 rpm (e.g., 120 rpm) to ensure that the conductor can rotate 10-100 times within a typical process cycle (30 seconds to 5 minutes) - for example, 30 times within a 60-second process cycle. The superposition of the compensation effect of each rotation is sufficient to fully average the magnetic field distribution. There is no need for excessively high speed (excessive speed will increase the motor load and conductor vibration risk), it is only necessary to be significantly faster than the process time scale.

[0130] By choosing to rotate in either clockwise or counterclockwise in a single direction, the sweep path and compensation time of the additional magnetic field on the surface of the target material 2 are completely consistent, further ensuring the uniformity of the compensation effect.

[0131] Specifically, the orthogonal electromagnetic field rotating magnetron sputtering device provided in this application further includes a second rotating drive mechanism, which is used to drive the current-carrying conductor 3 to rotate around the center of the working cavity 1.

[0132] The second rotary drive mechanism can be any drive component capable of driving the current-carrying conductor 3, such as a rotary cylinder or a motor. By setting a uniform speed of 50-200 rpm through the controller, it can directly drive the current-carrying conductor 3 to rotate. It has a simple structure, high transmission efficiency, and is suitable for the lightweight requirements of the current-carrying conductor 3.

[0133] More specifically, the rotational speeds of the first magnetic group 10 and the second magnetic group 20 are different from the rotational speed of the current-carrying conductor 3, and the ratio of their speeds is not an integer; the rotational directions of the first magnetic group 10 and the second magnetic group 20 are opposite to the rotational direction of the current-carrying conductor 3.

[0134] The first magnetic group 10 and the second magnetic group 20 need to rotate unidirectionally at a constant low to medium speed to avoid the formation of fixed etching marks on the target surface due to the instantaneous non-uniformity of their own magnetic fields. The first rotation drive mechanism drives the two magnetic groups to rotate synchronously around the working cavity 1, which can eliminate the instantaneous difference in the circumferential direction of the magnetic field by using time averaging, ensuring that a uniform etching ring is formed on the target surface, laying the foundation for optimizing the magnetic field for subsequent cooperation with the current-carrying conductor 3.

[0135] This makes the magnetic group and the current-carrying conductor 3 rotate in opposite directions (e.g., the magnetic group rotates clockwise and the conductor rotates counterclockwise), which can further disrupt the spatial superposition of the magnetic fields of the two by using the reverse motion.

[0136] The rotational speed of the magnetic assembly must differ from that of the current-carrying conductor 3, and the speed ratio must be a non-integer (preferably prime or irrational) to avoid moiré fringes or beat frequency effects caused by integer ratios (such as 1:1 or 2:1), and to prevent the periodic superposition of the non-uniformity of the magnetic fields of the two.

[0137] By rotating in opposite directions and using non-integer ratio rotation speeds, the inhomogeneity of the basic orthogonal magnetic field of the magnetic assembly and the additional compensating magnetic field of the conductor is fully dispersed in time and space. Thus, the rotation of the magnetic assembly can average the circumferential difference of the basic magnetic field, while the reverse rotation of the current-carrying conductor 3 can average the compensation deviation of the additional magnetic field. Furthermore, the non-integer ratio rotation speed ensures that the relative phase of the two never repeats, and no fixed superposition trace is formed. Ultimately, the target surface magnetic field is highly uniform throughout, avoiding local sputtering rate differences, so as to improve the uniformity of thin film deposition and the utilization rate of the target material.

[0138] In one specific embodiment, the diameter of the target material is 300 mm;

[0139] The first rotary drive mechanism drives the first magnetic group 10 and the second magnetic group 20 to rotate clockwise. The rotation speed is set to 100 rpm to ensure that the two magnetic groups rotate synchronously and achieve circumferential uniformity of the orthogonal magnetic field.

[0140] The second rotary drive mechanism drives the current-carrying conductor 3 to rotate counterclockwise at a speed of 37 rpm (the speed ratio between the magnetic group and the conductor is 100:37, which is not an integer, and 100 and 37 are prime numbers). This ensures that the relative phase between the magnetic group and the conductor never repeats within the process cycle.

[0141] Optionally, the effective length of the current-carrying conductor 3 is adjustable to adapt to different processes and achieve more comprehensive uniformity control; the effective length can be adaptively adjusted based on the current process or the consumption status of the target material 2.

[0142] It is easy to understand that different sputtering processes (such as depositing thin films of different materials such as Al, Ti, and Cu, or using target materials of different sizes such as 200mm and 300mm) have different requirements for the coverage range of the additional magnetic field; for example, small-diameter target materials require short conductors to focus and compensate for the weak central area, while large-diameter target materials require long conductors to expand the compensation range.

[0143] This allows the length of the current-carrying conductor 3 to be adjusted, which improves the compatibility of the magnetron sputtering device.

[0144] The current-carrying conductor 3 can be configured in the form of bending, telescopic, or threaded connection so that workers can manually adjust its length; or the length of the current-carrying conductor 3 can be automatically adjusted by configuring an automated drive device, such as a cylinder or electric cylinder.

[0145] For example, the current-carrying conductor 3 includes an outer tube and an inner core. The outer tube is a hollow copper tube (50mm in length), and the inner core is a copper conductor (30mm in length). The inner wall of the outer tube is provided with internal threads, and the outer wall of the inner core is provided with external threads. The outer tube and the inner core are connected by internal and external threads. During adjustment, the outer shell and the inner core are rotated relative to each other by a motor, which makes the inner core move along the axial direction of the outer tube, thereby changing the effective length of the current-carrying conductor 3.

[0146] In one embodiment, the target 2 is gradually consumed during sputtering (the target surface becomes thinner, and etching raceways appear at the edges), causing a change in the relative position between the surface of the target 2 and the current-carrying conductor 3. At this time, the additional magnetic field generated by the original effective length of the current-carrying conductor 3 deviates from the weak region. By adjusting the length of the current-carrying conductor 3, the target 2 can be re-aligned with the current weak magnetic field region, ensuring that the compensation effect is effective.

[0147] In another embodiment, different processes have different requirements for film uniformity (e.g., substrate manufacturing requires a deviation within ±2%, and ordinary coating requires a deviation within ±5%). By changing the length of the current-carrying conductor 3, the magnetic field coverage and intensity of the current-carrying conductor 3 can be changed, thereby optimizing the local uniformity in a targeted manner and avoiding over-compensation or under-compensation.

[0148] In another embodiment, the remaining thickness of the target material 2 is monitored in real time by a target material thickness sensor (such as a laser displacement sensor), and the change in the effective sputtering area on the surface of the target material 2 is calculated by combining the initial thickness and the consumption rate; when the target material 2 is consumed to a preset threshold (such as the remaining thickness being 50% of the initial thickness), or when the magnetic field sensor detects that the central weak area shift exceeds a preset range (such as ±5%), the length adjustment of the energized conductor 3 is triggered.

[0149] Specifically, the target thickness sensor feeds back the consumption data and magnetic field data of the target 2 to the control unit. The control unit calculates the target length according to a preset algorithm (e.g., 1 mm of target material consumption corresponds to an increase of 0.5 mm in conductor length) and adjusts the conductor length accordingly. For example, an initial 300 mm Ti target corresponds to a conductor length of 40 mm. After 2 mm of target material consumption, the conductor length is automatically adjusted to 41 mm to ensure that the additional magnetic field always covers the central weak area of ​​the target 2.

[0150] In one specific embodiment, the orthogonal electromagnetic field rotating magnetron sputtering device provided in this application includes multiple current-carrying conductors 3 of different lengths, which are arranged at the same point in a radially centrally symmetrical structure; in use, at least one of the current-carrying conductors 3 can be selectively energized as needed.

[0151] For details, please refer to Figure 5In the illustrated embodiment, multiple current-carrying conductors 3 are radially distributed outwards from a common origin (common point) on the axis where the center of the target material 2 is located, and the whole structure satisfies the characteristics of central symmetry. Any current-carrying conductor 3 is arranged in a long straight line, with its midpoint as the center of rotation. The centers of all current-carrying conductors 3 intersect at the common origin. The conductors are mutually insulated, non-conductive, and independently energized; both ends of any current-carrying conductor 3 extend towards the edge of the target material 2. The effective lengths of each current-carrying conductor 3 are different (e.g., 20mm, 30mm, 40mm, and 50mm respectively).

[0152] In use, the required length of the current-carrying conductor 3 is selectively conducted according to the target size, sputtering material, and other process requirements. For example, for a small-diameter target 2 of 200mm, only current-carrying conductors 3 of 20mm and 30mm in length are conducted to focus and compensate for the weak central area of ​​the target 2; for a large-diameter target 2 of 300mm, additional current-carrying conductors 3 of 40mm and 50mm are conducted to expand the compensation range of the magnetic field and ensure that the magnetic field at the edge of the target 2 is uniform.

[0153] After long-term sputtering, the edges of target 2 are prone to etching raceways, which leads to a relative weakening of the magnetic field in the edge region. After detecting the deviation of the edge magnetic field by the magnetic field sensor, the system can switch from conducting only the short conductor to conducting the long conductor. The additional magnetic field with a larger coverage area of ​​the long conductor is used to reinforce the weak edge area of ​​target 2, thereby maintaining the overall magnetic field uniformity.

[0154] Each current-carrying conductor 3 is independently connected to a current control switch and adjustment module. In use, a current-carrying conductor 3 of a certain length can be turned on individually, or multiple current-carrying conductors 3 can be turned on in combination. Through the superposition of magnetic fields, the equivalent intermediate length compensation effect can also be achieved (such as the combination of 30mm + 40mm current-carrying conductors 3, which can be equivalent to the magnetic field coverage of a conductor of 35mm length).

[0155] The combination of different lengths of current-carrying conductors 3 allows the magnetron sputtering device to be adapted to targets 2 of different diameters and processes for different sputtering materials such as Al, Ti, and Cu without changing the current-carrying conductors 3, thus improving the compatibility of the equipment. By selectively conducting current-carrying conductors 3 of different lengths, it is also possible to specifically reinforce the weak magnetic field areas in different regions such as the center, middle ring, and edge of the target 2, avoiding the problems of over-compensation or under-compensation that exist with fixed-length current-carrying conductors 3.

[0156] Optionally, a magnetic window is provided on the cavity cover 1a of the working cavity 1. The magnetic window is made of soft magnetic material. A current-carrying conductor 3 is provided on the magnetic window. The magnetic window can efficiently attract and guide the external magnetic field through the cavity cover 1a and act on the working cavity 1.

[0157] In one embodiment, the magnetic window is disc-shaped and located in the center of the cavity cover 1a, directly opposite the target material 2. In this case, the magnetic window is set as part of the cavity cover 1a (the cavity cover 1a has an opening in the center, and the magnetic window is sealed in the opening), and the current-carrying conductor 3 is disposed on the magnetic window.

[0158] In another embodiment, the cavity cover 1a is made of a soft magnetic material, and the cavity cover 1a can be used as a magnetic window.

[0159] Soft magnetic materials, such as electrical pure iron (preferably DT4C grade electrical pure iron) and silicon steel sheets (such as 30Q130 low-loss silicon steel sheets), have the characteristics of high magnetic permeability and low coercivity, which can significantly reduce the magnetic resistance of the magnetic field passing through the cavity cover 1a, so that the additional magnetic field generated by the current-carrying conductor 3 can pass through the cavity cover 1a more efficiently and act on the working cavity 1, avoiding magnetic field attenuation caused by the non-magnetic nature of the cavity cover 1a.

[0160] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An orthogonal electromagnetic field rotating magnetron sputtering apparatus, comprising a working chamber (1) and a target material (2) disposed within the working chamber (1), characterized in that, Also includes: The first magnetic group (10) is disposed on one side of the working cavity (1). The first magnetic group (10) includes a plurality of permanent magnets, which are distributed circumferentially along the working cavity (1). The second magnetic group (20) is located on the other side of the working cavity (1). The second magnetic group (20) also includes a plurality of permanent magnets. The plurality of permanent magnets are also distributed circumferentially along the working cavity (1). The first magnetic group (10) and the second magnetic group (20) are arranged opposite to each other about the center of the working cavity (1). The permanent magnets in the first magnetic group (10) have opposite magnetic poles to the permanent magnets in the first magnetic group (10). A first rotary drive mechanism is used to drive the first magnetic group (10) and the second magnetic group (20) to rotate around the center of the working cavity (1); The magnetic lines of the first magnetic group (10) and the second magnetic group (20) are coupled below the target material (2) to form an orthogonal magnetic field parallel to the surface of the target material (2). The orthogonal magnetic field can make the electrons in the magnetron sputtering process more effectively subjected to the Lorentz force, thereby extending the movement path of the electrons and increasing the ionization rate of the reaction gas. The orthogonal electromagnetic field rotating magnetron sputtering device also includes a current-carrying conductor (3), which is arranged parallel to the surface of the target material (2) and faces the central region of the target material (2); The current-carrying conductor (3) is used to generate an additional magnetic field to enhance the weak regions of the orthogonal magnetic field.

2. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 1, characterized in that, The permanent magnet is a neodymium iron boron permanent magnet or a samarium cobalt permanent magnet; And / or, the permanent magnet is provided with a magnetic yoke made of a high magnetic permeability material on the side away from the center of the working cavity (1). The magnetic yoke can form a low magnetic resistance path, reduce magnetic circuit leakage, and guide and concentrate more magnetic lines of force to the working area below the target (2), thereby effectively enhancing the magnetic field strength of the working area and optimizing its distribution pattern. And / or, the orthogonal electromagnetic field rotating magnetron sputtering device further includes an electromagnetic enhancement coil, which is wound around the outside of the working cavity (1). The direction of the magnetic field generated by the electromagnetic enhancement coil is consistent with the direction of the orthogonal magnetic field, which can enhance the magnetic field as a whole. And / or, a gap is provided between the first magnetic group (10) and the second magnetic group (20), the gap being configured to prevent a magnetic short circuit between the first magnetic group (10) and the second magnetic group (20), thereby forcing magnetic force across the working cavity (1) to form the orthogonal magnetic field; And / or, a magnetic isolation block is provided between the first magnetic group (10) and the second magnetic group (20), and the magnetic permeability of the magnetic isolation block is much lower than the magnetic permeability of the permanent magnet.

3. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 1, characterized in that, The first magnetic group (10) and the second magnetic group (20) also include arc-shaped supports. The working cavity (1) is located between the two arc-shaped supports. The arc-shaped supports can rotate around the center of the working cavity (1) under the drive of the first rotary drive mechanism. The arc-shaped bracket is provided with multiple mounting holes, each of which is used to mount one of the permanent magnets; The arc-shaped support is made of non-magnetic material; The arc-shaped bracket is provided with a cooling channel, which passes through all the mounting holes and circulates cooling water into the cooling channel, thereby actively dissipating heat from the permanent magnet.

4. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 1, characterized in that, There is an angle between the central axis of the permanent magnet and the radial direction of the working cavity (1), and the angle is configured to maximize the component of the magnetic field generated by the permanent magnet that is parallel to the surface of the target material (2). The magnitude of the tilt angle can be determined through electromagnetic simulation experiments.

5. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 1, characterized in that, The current-carrying conductor (3) is rotatably disposed above the target material (2), and its axis of rotation is perpendicular to the surface of the target material (2); This causes the current-carrying conductor (3) to rotate, which can homogenize the compensation effect it produces in space, so as to achieve global uniformity of the magnetic field.

6. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 5, characterized in that, It also includes a second rotary drive mechanism, which is used to drive the current-carrying conductor (3) to rotate around the center of the working cavity (1); The rotational speeds of the first magnetic group (10) and the second magnetic group (20) are different from the rotational speed of the current-carrying conductor (3), and the ratio of their speeds is not an integer; The rotation directions of the first magnetic group (10) and the second magnetic group (20) are opposite to the rotation direction of the current-carrying conductor (3).

7. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 1, characterized in that, The effective length of the current-carrying conductor (3) is adjustable in order to adapt to different processes and achieve more comprehensive uniformity control; The effective length can be adaptively adjusted based on the current process or the consumption status of the target material (2).

8. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 7, characterized in that, It includes multiple current-carrying conductors (3) of different lengths, and the multiple current-carrying conductors (3) are arranged at the same point in a radially centrally symmetrical structure; When in use, at least one of the energized conductors (3) may be selectively energized as needed.

9. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 1, characterized in that, The working chamber (1) has a magnetic window on its cover (1a), which is made of soft magnetic material; The current-carrying conductor (3) is disposed on the magnetic window; The magnetic window can efficiently attract and guide the external magnetic field through the cavity cover (1a) and act on the working cavity (1).

10. The orthogonal electromagnetic field rotating magnetron sputtering apparatus according to claim 1, characterized in that, The current-carrying conductor (3) is made of oxygen-free copper with a purity of ≥99.95%, and has a hollow tubular structure. Circulating cooling water can flow through the tube. And / or, the distance between the current-carrying conductor (3) and the target material (2) is controlled to be 5-15 mm.

Images