A method of controlling the motion of a magnetron

Abstract

This invention discloses a method for controlling the motion of a magnetron, applied to a magnetron sputtering source. The magnetron sputtering source includes a magnetron and a driving device. The driving device controls the magnetron's rotation and revolution around the center of the target material to periodically scan the entire target area. The method also modifies the magnetron's revolution and rotation angular velocities to ensure that the magnetron's trajectory does not overlap within one motion cycle. This invention can achieve efficient utilization of the target material and uniform film thickness by optimizing the magnetron's trajectory and magnetic field distribution.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a method for controlling the movement of a magnetron. Background Technology

[0002] Magnetron sputtering is a vacuum deposition technique based on bombarding a target surface with charged ions. This technique uses charged ions (high-speed particle beams accelerated in a vacuum) to continuously bombard the target surface, causing the target atoms to gain sufficient reactive energy to detach from the surface and deposit onto the substrate, forming the desired thin film layer. This technology has been widely used in many high-tech fields such as integrated circuits, flat panel displays, photovoltaics, and LEDs.

[0003] However, magnetron sputtering technology also faces a series of challenges in its application, the most prominent of which is the low target utilization rate. During sputtering, a ring-shaped magnetic field is formed on the target surface, and the ion beam etches the target in specific areas, resulting in faster target consumption in those areas. In areas with weaker magnetic field distribution, the target is etched to a relatively smaller degree, which often leads to low overall target utilization when the expected lifetime is reached.

[0004] Improving the uniformity of thin film (e.g., metal ion) deposition on the substrate surface and the utilization rate of the target material are urgent problems to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling the motion of a magnetron, which optimizes the magnetic field distribution and the running trajectory of the magnetron to achieve efficient utilization of the target material and uniform deposition of the thin film.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] A method for controlling the motion of a magnetron is applied to a magnetron sputtering source, the magnetron sputtering source including a magnetron and a driving device, the driving device being used to control the rotation of the magnetron and its revolution around the center of the target material to periodically scan the entire target material area; the method also involves changing the revolution angular velocity and rotation angular velocity of the magnetron to ensure that the trajectory of the magnetron does not overlap within one motion cycle.

[0008] Optionally, the ratio of the revolution angular velocity to the rotation angular velocity is controlled to be a fixed constant within one motion cycle, so that the running trajectories of the magnetron do not overlap.

[0009] Optionally, the absolute value of the linear velocity of the magnetron on its operating trajectory remains consistent.

[0010] Optionally, the ratio of the orbital angular velocity to the rotational angular velocity of the magnetron is the same in different motion cycles.

[0011] Optionally, when the ratio between the orbital radius and the rotational radius of the magnetron is 2n1, where n1 is a positive integer, the ratio of the orbital angular velocity to the rotational angular velocity is controlled to satisfy the following condition:

[0012]

[0013] In the formula, ω2 represents the orbital angular velocity of the magnetron, ω1 represents the rotational angular velocity of the magnetron, and C represents a constant; Where n2 is any positive integer from 1 to 8n1.

[0014] Optionally, a constant C is chosen such that At this point, the magnetron's operating path within one motion cycle is the longest.

[0015] Optionally, the orbital angular velocity ω2 of the magnetron is calculated using the following formula:

[0016]

[0017] In the formula, L0 represents the initial distance between the magnetron and the center of the target; L represents the current distance between the magnetron and the center of the target; ω2 i This represents the angular velocity of the magnetron's revolution at the starting point;

[0018] The rotational angular velocity ω1 of the magnetron is calculated using the following formula:

[0019]

[0020] Optionally, the initial distance between the magnetron and the center of the target is calculated using the following formula:

[0021]

[0022] In the formula, (X0,Y0) represents the initial coordinates of the magnetron;

[0023] The distance between the magnetron and the center of the target at the current moment is calculated using the following formula:

[0024]

[0025] In the formula, (X, Y) represents the position coordinates of the magnetron at the current moment.

[0026] Optionally, the real-time position coordinates of the magnetron are calculated using the following formula:

[0027] X=a×cos(ω2×t+θ2)+b×cos(ω1×t+θ1)

[0028] Y=a×sin(ω2×t+θ2)+b×sin(ω1×t+θ1)

[0029] In the formula, a represents the orbital radius of the magnetron, b represents the rotational radius of the magnetron, θ2 and θ1 are the initial phases of the magnetron's orbit and rotation, respectively; t represents time.

[0030] On the other hand, the present invention also provides an electronic device including a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, it implements the method described above.

[0031] In other respects, the present invention also provides a readable storage medium storing a computer program that, when executed by a processor, implements the method described above.

[0032] This invention has at least one of the following technical effects:

[0033] This invention controls the orbital and rotational angular velocities of the magnetron to ensure that its trajectory does not overlap within one motion cycle. This improves the uniformity of the magnetic field strength distribution along the trajectory, effectively controls the uniformity of plasma distribution within the cavity of the magnetron sputtering equipment, thereby enhancing the uniformity of trench depth across the target material, the uniformity of thin film deposition, and ultimately improving the overall utilization rate of the target material.

[0034] This invention controls the ratio of the orbital angular velocity to the rotational angular velocity of the magnetron to be the same in different motion cycles. That is, during the physical vapor deposition (PVD) process, the magnetron's trajectory on the target surface is kept constant and does not overlap, which can maintain good uniformity of the etching depth (groove depth at various points on the target surface).

[0035] This invention dynamically adjusts the revolution angular velocity and rotation angular velocity of the magnetron within one motion cycle, keeping the ratio of the two constant, thus enabling the magnetron to move at a uniform speed along its trajectory. This ensures that the residence time of the magnetron along its trajectory is equal at all points, thereby further improving the uniformity of the trench depth throughout the target material. It can effectively control the uniformity of plasma distribution inside the cavity of the magnetron sputtering equipment and the uniformity of thin film deposition.

[0036] This invention optimizes the target material utilization rate by selecting a constant that maximizes the operating path of the magnetron within one motion cycle. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the existing magnetron sputtering source on the target surface on which the present invention is based;

[0038] Figure 2 A comparative schematic diagram of various non-overlapping operating trajectories of a magnetron provided in an embodiment of the present invention;

[0039] Figure 3 A schematic diagram of the operating trajectory of a magnetron provided in an embodiment of the present invention;

[0040] Figure 4 A comparative schematic diagram of multiple overlapping operating trajectories of a magnetron provided in an embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram comparing the effects of uniform and non-uniform target etching according to an embodiment of the present invention. Detailed Implementation

[0042] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the magnetron motion control method proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, intended only to facilitate and clearly illustrate the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0043] As described in the background section, magnetron sputtering technology suffers from low target utilization and uneven deposition of thin films (e.g., metal ions) on the substrate surface.

[0044] Specifically, during sputtering, a ring-shaped magnetic field forms on the target surface, causing the ion beam to concentrate its etching within a specific area. Target surfaces located in areas with weaker or no magnetic field coverage experience relatively less etching. This uneven etching phenomenon often results in low overall target utilization when the expected lifetime is reached, especially for planar targets such as ITO (indium tin oxide), where utilization typically does not exceed 40%. This not only increases production costs but also limits the further development and application of magnetron sputtering technology.

[0045] Studies have found that the uniformity of plasma distribution inside the cavity of a magnetron sputtering device has a significant impact on the utilization rate of the target material and the quality of thin film deposition, and it is closely related to the distribution of the magnetic field and the operating trajectory of the magnetron. Therefore, by effectively controlling the magnetic field distribution on the target surface, it is expected to improve the deposition uniformity of metal ions on the substrate surface (the uniformity of thin film deposition) and increase the overall utilization rate of the target material.

[0046] In view of this, this embodiment provides a method for controlling the motion of a magnetron, applied to a magnetron sputtering source. The magnetron sputtering source includes a magnetron and a driving device. The driving device is used to control the magnetron to rotate on its own axis while also revolving around the center of the target material to scan the entire target material area. The method includes: adjusting the angular velocity of the magnetron's revolution and rotation to ensure that the magnetron's trajectory does not overlap within one motion cycle.

[0047] This embodiment controls the orbital and rotational angular velocities of the magnetron to ensure that its trajectory does not overlap within one motion cycle. Because the magnetic field binds electrons, the plasma concentration is higher in the trajectory region, resulting in more pronounced etching of the target material by cations in this region, thus shortening the target lifespan in the corresponding area. If overlapping trajectories exist, the etching of the target material by cations in the overlapping region increases compared to non-overlapping regions, reducing the target lifespan in this region. This embodiment ensures that the magnetron's trajectory does not overlap within one motion cycle, thereby improving the uniformity of the magnetic field strength distribution along the trajectory. This effectively controls the uniformity of plasma distribution within the magnetron sputtering chamber, improving the uniformity of trench depth across the target material and the uniformity of thin film deposition, ultimately increasing the overall utilization rate of the target material.

[0048] Specifically, in this embodiment, the ratio of the revolution angular velocity to the rotation angular velocity can be controlled to be a fixed constant within one motion cycle, so that the running trajectories of the magnetron do not overlap.

[0049] It is understandable that the operating trajectory of the magnetron can be designed in advance.

[0050] In this embodiment or other embodiments, the ratio of the orbital angular velocity to the rotational angular velocity of the magnetron is the same in different motion cycles.

[0051] In the physical vapor deposition (PVD) process, by controlling the ratio of the revolution angular velocity to the rotation angular velocity to be constant, the trajectory of the magnetron on the target surface is fixed and non-overlapping. The plasma etching effect on the target is always at the same location, thus achieving good uniformity in etching depth at various positions along the trajectory (see details...). Figure 5 (As shown).

[0052] In this embodiment, as Figure 1 As shown, it presents a simplified structural diagram of a magnetron sputtering source.

[0053] The magnetron sputtering source includes: a main shaft O1 located at the center of the target 10, and a main shaft rotating arm 20 disposed at one end of the main shaft O1; a first counterweight 30 is provided on one side of the main shaft rotating arm 20, and a rotation axis structure is provided on the other side. The rotation axis structure includes a rotation axis O2 disposed on the main shaft rotating arm 20, and a rotation arm 21 disposed on the rotation axis O2. A second counterweight 31 and a magnetron 40 are respectively disposed at both ends of the rotation arm 21, wherein the main shaft O1 is the origin of the coordinate system. The main shaft rotating arm 20 rotates around the main shaft O1, and the rotation arm 21 rotates around the rotation axis O2. During the rotation of the main shaft rotating arm 20, it can drive the rotation axis structure to revolve, thereby driving the magnetron 40 to revolve. During the rotation of the rotating arm 21, the magnetron 40 is driven to rotate. It can be understood that the magnetron 40 is also revolving around the rotation axis O2 at this time. However, for ease of distinction, this process is considered to be the rotation process of the magnetron, and the resulting angular velocity is also called the rotation angular velocity. That is, the motion of the magnetron can be a planetary motion.

[0054] Therefore, the real-time position coordinates of the magnetron in this magnetron sputtering source can be calculated using the following formula:

[0055] X=a×cos(ω2×t+θ2)+b×cos(ω1×t+θ1) (1)

[0056] Y=a×sin(ω2×t+θ2)+b×sin(ω1×t+θ1) (2)

[0057] In the formula, a represents the orbital radius of the magnetron, b represents the rotational radius of the magnetron, θ2 and θ1 are the initial phases of the magnetron's orbit and rotation, respectively; t represents time.

[0058] In this embodiment, the orbital angular velocity ω2 of the magnetron is calculated using the following formula:

[0059]

[0060] In the formula, L0 represents the initial distance between the magnetron and the center of the target; L represents the current distance between the magnetron and the center of the target; ω2 i This represents the angular velocity of the magnetron's revolution at the starting point;

[0061] The rotational angular velocity ω1 of the magnetron is calculated using the following formula:

[0062]

[0063] In the formula, C represents a constant.

[0064] The initial distance between the magnetron and the center of the target is calculated using the following formula:

[0065]

[0066] In the formula, (X0,Y0) represents the initial coordinates of the magnetron;

[0067] The distance between the magnetron and the center of the target at the current moment is calculated using the following formula:

[0068]

[0069] In the formula, (X, Y) represents the position coordinates of the magnetron at the current moment.

[0070] In this embodiment or other embodiments, when the ratio between the orbital radius *a* and the rotational radius *b* of the magnetron is 2n1, where *n1* is a positive integer, the ratio of the orbital angular velocity to the rotational angular velocity is controlled to satisfy the following condition:

[0071]

[0072] In the formula, Where n2 is any positive integer from 1 to 8n1.

[0073] In this embodiment or other embodiments, a constant C can be selected such that... At this point, the magnetron has the longest running path within one motion cycle, thereby further improving the utilization rate of the target material.

[0074] In this embodiment or other embodiments, within one motion cycle, the revolution angular velocity and rotation angular velocity of the magnetron are dynamically adjusted so that the ratio of the two remains a fixed constant, thereby enabling the magnetron to move at a constant speed on its trajectory.

[0075] This ensures that the residence time of the magnetron along its trajectory is equal at all points, thereby further improving the uniformity of the groove depth at all points on the target material. This effectively controls the uniformity of plasma distribution inside the cavity of the magnetron sputtering equipment and the uniformity of thin film deposition.

[0076] It is understandable that when adjusting the revolution angular velocity and rotation angular velocity of the magnetron, the angular acceleration satisfies α2=dω2 / dt, α1=dω1 / dt, and α2 / α1 is equal to ω2 / ω1 and is C.

[0077] For example, such as Figure 2As shown, when a / b=2, ω2 / ω1=1 / n (n=1,2,3…8), the magnetrons do not overlap within one operating cycle.

[0078] Specifically, such as Figure 2 Figure (a) shows the trajectory of the magnetron when its revolution angular velocity ω2 = 2π / s, its spin angular velocity ω1 = 16π / s, and ω2 / ω1 = 1 / 8.

[0079] from Figure 2 As can be seen in Figure (a), the distribution of the running trajectory on the target surface is relatively dispersed. At the same time, because the magnetron passes through the central region of the target multiple times in one running cycle, the film thickness deposited in the central region of the substrate is relatively high. Meanwhile, according to the above formulas (3) and (4), by calculating and adjusting the orbital and rotational angular velocities of the magnetron and keeping the ratio of ω2 / ω1 constant, its scanning trajectory on the target surface will not change, but the dwell time in the corresponding region will be shorter. This characteristic can be used to adjust the orbital and rotational angular velocities of the magnetron to improve the uneven etching phenomenon on the target surface and improve the target life and utilization rate.

[0080] like Figure 2 Figure (b) shows the trajectory of the magnetron when its revolution angular velocity ω2 = 2π / s, its spin angular velocity ω1 = 8π / s, and ω2 / ω1 = 1 / 4.

[0081] like Figure 2 Figure (c) shows the trajectory of the magnetron when its revolution angular velocity ω2 = π / s, its spin angular velocity ω1 = 2π / s, and ω2 / ω1 = 1 / 2.

[0082] like Figure 2 As shown in Figure (d), it shows the trajectory of the magnetron when the magnetron's revolution angular velocity ω2 = 2π / s, the magnetron's spin angular velocity ω1 = 2π / s, and ω2 / ω1 = 1.

[0083] When ω2 / ω1 = 1 / 4, the magnetron's trajectory is centrally symmetrical, and the path length within one cycle is longer than when ω2 / ω1 = 1. However, when the magnetron moves to a position close to the target center, its dwell time is long, resulting in a higher film thickness in the central region of the substrate. To improve this, the magnetron's revolution and rotation angular velocities can be adjusted simultaneously while maintaining a constant ω2 / ω1 ratio, thus shortening the dwell time in this region without changing the scanning trajectory. When ω2 / ω1 = 1 / 2, the magnetron's trajectory is an axisymmetric pattern, but its plasma uniformity is not as good as other centrally symmetrical patterns. When ω2 / ω1 = 1, the scanning trajectory is a circular pattern with excellent symmetry, but the target utilization rate is low.

[0084] Therefore, the smaller the value of ω2 / ω1, the longer the trajectory within one operating cycle. Thus, the optimal choice is to select the magnetron's operating trajectory when ω2 / ω1 = 1 / 8, which maximizes the utilization rate of the target material.

[0085] Preferably, such as Figure 3 As shown, the magnetron's trajectory is when ω2=2π / sω1=16π / s and ω2 / ω1=1 / 8. This trajectory will not have obvious overlap. By calculating and adjusting the magnetron's revolution and rotation angular velocities in real time according to the above formulas (3) and (4) and always keeping ω2 / ω1=1 / 8, the magnetron's trajectory can be kept relatively uniform from the outer circle to the inner circle, thereby ensuring the etching uniformity of the target material and improving the target material utilization rate.

[0086] like Figure 4 As shown, if ω2 / ω1 ≠ 1 / n (i.e., ω1 is not divisible by ω2, or ω2 / ω1 is less than 1 / 8), the following will occur: Figure 4 As shown in Figure (a), ω2 = 2π / s, ω1 = 19π / s, ω2 / ω1 = 2 / 19, and for example... Figure 4 As shown in Figure (b), the orbital trajectory with ω2 = 2π / s, ω1 = 18π / s, and ω2 / ω1 = 1 / 9 results in a large overlap area, leading to uneven etching of the target material and reduced target utilization. Therefore, a smaller ω2 / ω1 ratio results in a longer total path distance within one cycle, higher target utilization, but also more overlapping areas and more frequent uneven etching on the target surface. Thus, the optimal ratio range in this embodiment is greater than or equal to 1 / 8.

[0087] Figure 5 Images (a) and (b) illustrate the surface morphology of the target 10 with different etching degrees.

[0088] (a) illustrates the morphology of the target material with uneven etching, and (b) illustrates the morphology of the target material with uniform etching. The bottom of the etched trenches 11 at different depths has different magnetic field strengths due to the influence of the magnetron above. Since the magnetic field strength on the surface of the target trenches 11 is greatly affected by its etching depth, controlling the uniformity of the surface etched trenches 11 depth effectively controls the plasma uniformity inside the cavity and the uniformity of thin film deposition.

[0089] On the other hand, the present invention also provides an electronic device including a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, it implements the method described above.

[0090] In other respects, the present invention also provides a readable storage medium storing a computer program that, when executed by a processor, implements the method described above.

[0091] In summary, this invention can effectively control the residence time of the magnetron in a specific area on the target surface while keeping the magnetron's trajectory on the target surface constant, thereby effectively improving the target life, overall utilization rate, and plasma uniformity during the process.

[0092] Traditional PVD machines use magnetrons that only control the angular velocity of their spindle to alter their trajectory. Adjusting different spindle angular velocities is equivalent to splicing together different ω2 / ω1 trajectories, often resulting in poor symmetry. Consequently, the magnetron's dwell time varies across different areas of the target surface, ultimately affecting the target's lifespan. This invention, however, maintains a constant ratio between the spindle's revolution angular velocity and the magnetron's spindle angular velocity, thus determining the magnetron's trajectory on the target surface. Furthermore, simultaneously increasing or decreasing the spindle angular velocity ω1 and the revolution angular velocity ω2 adjusts the magnetron's dwell time at specific locations. This allows the magnetron to maintain linear, uniform motion without altering its trajectory, ensuring consistent dwell time across all areas. This improves the uniformity of target etching and the uniformity of film deposition thickness on the substrate.

[0093] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0094] It should be noted that the apparatus and methods disclosed in the embodiments herein can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments herein.

[0095] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for controlling the motion of a magnetron, applied to a magnetron sputtering source, the magnetron sputtering source comprising a magnetron and a driving device, the driving device controlling the magnetron to rotate and revolve around the center of a target material, so as to periodically scan the entire target material area; characterized in that, The method includes: By changing the orbital angular velocity and rotational angular velocity of the magnetron, the orbital trajectories of the magnetron within one motion cycle do not overlap.

2. The method for controlling the motion of a magnetron as described in claim 1, characterized in that, The ratio of the revolution angular velocity to the rotation angular velocity is controlled to be a fixed constant within one motion cycle, so that the running trajectories of the magnetron do not overlap.

3. The method for controlling the movement of a magnetron as described in claim 2, characterized in that, The absolute value of the linear velocity of the magnetron on its running trajectory remains consistent.

4. The method for controlling the movement of a magnetron as described in claim 2, characterized in that, The ratio of the magnetron's revolution angular velocity to its rotation angular velocity remains the same throughout different motion cycles.

5. The method for controlling the motion of a magnetron as described in claim 2, characterized in that, When the ratio between the magnetron's orbital radius and its rotational radius is 2n1, where n1 is a positive integer, The ratio of the revolution angular velocity to the rotation angular velocity is controlled to satisfy the following condition: In the formula, ω2 represents the orbital angular velocity of the magnetron, ω1 represents the rotational angular velocity of the magnetron, and C represents a constant; Where n2 is any positive integer from 1 to 8n1.

6. The method for controlling the motion of a magnetron as described in claim 4, characterized in that, Choose a constant C such that At this point, the magnetron's operating path within one motion cycle is the longest.

7. The method for controlling the motion of a magnetron as described in claim 5, characterized in that, The orbital angular velocity ω2 of the magnetron is calculated using the following formula: In the formula, L0 represents the initial distance between the magnetron and the center of the target; L represents the current distance between the magnetron and the center of the target; ω2 i This represents the angular velocity of the magnetron's revolution at the starting point; The rotational angular velocity ω1 of the magnetron is calculated using the following formula:

8. The method for controlling the motion of a magnetron as described in claim 7, characterized in that, The initial distance between the magnetron and the center of the target is calculated using the following formula: In the formula, (X0,Y0) represents the initial coordinates of the magnetron; The distance between the magnetron and the target center at the current moment is calculated using the following formula: In the formula, (X, Y) represents the position coordinates of the magnetron at the current moment.

9. The method for controlling the motion of a magnetron as described in claim 8, characterized in that, The real-time position coordinates of the magnetron are calculated using the following formula: X=a×cos(ω2×t+θ2)+b×cos(ω1×t+θ1) Y=a×sin(ω2×t+θ2)+b×sin(ω1×t+θ1) In the formula, a represents the orbital radius of the magnetron, b represents the rotational radius of the magnetron, θ2 and θ1 are the initial phases of the magnetron's orbit and rotation, respectively; t represents time.

10. An electronic device, characterized in that, It includes a processor and a memory, wherein the memory stores a computer program, which, when executed by the processor, implements the method of any one of claims 1 to 9.

11. A readable storage medium, characterized in that, The readable storage medium stores a computer program, which, when executed by a processor, implements the method of any one of claims 1 to 9.

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