A magnetron system for large area thin film production

Abstract

This invention belongs to the technical field of magnetron sputtering thin film deposition and discloses a magnetron sputtering system for large-area thin film preparation. The magnetron sputtering system includes a deposition substrate and a moving target, with the substrate and target positioned opposite each other. The moving target includes a target material, a gas supply ring, and a dynamic magnet. The target material is connected to an electric field cathode, making it the cathode target for magnetron sputtering. The gas supply ring provides reactive gas to the area around the target material. The dynamic magnet, located within the moving target, provides an adjustable magnetic field around the target material. When the center of the moving target is on the same horizontal line as the center of the deposition substrate, the magnetic field range is minimized, resulting in the smallest deposition spot area on the substrate. As the moving target moves away from the center of the deposition substrate along its radius, the magnetic field range gradually increases, and the deposition spot area on the substrate gradually increases. This invention solves the problem of difficulty in controlling the deposition uniformity in large-area thin film preparation in existing technologies.

Description

Technical Field

[0001] This invention belongs to the technical field of magnetron sputtering thin film deposition, and more specifically, relates to a magnetron system for large-area thin film preparation. Background Technology

[0002] Magnetron sputtering is a metal and compound thin film deposition technique. The films prepared using this technique exhibit high uniformity and density, making it widely applicable in integrated circuits, wear-resistant and corrosion-resistant coatings, optical coatings, large-area coatings for architectural glass, and photovoltaic solar cells, enabling low-cost, large-scale industrial production. The magnetron sputtering process is performed in a high-vacuum environment. The cathode target is bombarded by high-energy argon ions generated in a glow discharge plasma, sputtering out a large number of target particles. Ultimately, the target metal is deposited on the substrate surface, forming a film. Compared to other thin film deposition techniques such as chemical vapor deposition and multi-arc ion plating, magnetron sputtering offers advantages such as high speed, low temperature, and low damage.

[0003] With the development of industries such as semiconductors, the fabrication of large-area, high-quality thin films has become fundamental to the development of next-generation electronic and optoelectronic devices. Magnetron sputtering technology for depositing large-area uniform thin films has become a key technological advancement. Large-area thin films are typically composed of multiple elements and, depending on requirements, can be prepared into materials with properties such as high-temperature resistance, corrosion resistance, oxidation resistance, and high hardness. These materials can be applied to high-quality organic semiconductor thin films, thermal protection coatings for high-speed aircraft, and light-absorbing layers for solar cells. Maintaining uniformity over a large area is crucial for large-area film fabrication. However, traditional magnetron sputtering methods have limited substrate and target stage dimensions. Existing improvements include simultaneously increasing the size of the substrate and target stages, or increasing and moving the substrate stage. These methods suffer from problems such as bulky equipment, low production efficiency, and difficulty in ensuring film uniformity. The complexity of the system and the low quality of the film limit their industrial applications. Therefore, designing a magnetron sputtering system and method capable of achieving uniform fabrication of large-area thin films is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides a magnetron sputtering system for large-area thin film preparation, which solves the problem of difficulty in controlling the deposition uniformity of large-area thin film preparation in the prior art.

[0005] To achieve the above objectives, according to the present invention, a magnetron sputtering system for large-area thin film fabrication is provided, the magnetron sputtering system comprising a deposition substrate and a moving target, wherein,

[0006] The deposition substrate is disposed opposite to the moving target and can rotate around its own center. The moving target includes a target material, a gas supply ring, and a dynamic magnet. The target material is disposed at the top of the moving target and is connected to the electric field cathode so that the target material serves as the cathode target for magnetron sputtering. The gas supply ring is used to provide reactive gas to the area around the target material. The dynamic magnet is disposed in the moving target and is used to provide an adjustable magnetic field around the target material.

[0007] When the center of the moving target is on the same horizontal line as the center of the deposition substrate, the magnetic field range is the smallest and the deposition spot area formed on the deposition substrate is the smallest. When the moving target moves away from the center of the deposition substrate along the radial direction of the deposition substrate, the magnetic field range gradually increases and the deposition spot area formed on the deposition substrate gradually increases.

[0008] During magnetron sputtering deposition, the rotation of the deposition substrate and the movement of the moving target enable the deposition spot to completely scan the surface of the deposition substrate. The rotation speed and moving speed are adjusted to control the position of the deposition spot and the deposition time, thereby achieving uniform deposition of large-area thin films.

[0009] More preferably, the dynamic magnet includes an inner magnet and an outer magnet. The inner magnet is fixed at the center of the moving target, and the outer magnet gradually moves away from the inner magnet as the moving target moves away from the center of the deposition substrate along the radial direction of the deposition substrate, thereby gradually increasing the magnetic field range.

[0010] More preferably, the magnetic poles of the inner magnet and the outer magnet are opposite in direction. When the magnetic field range shrinks, the distance between the inner magnet and the outer magnet decreases; when the magnetic field range expands, the distance between the inner magnet and the outer magnet increases.

[0011] More preferably, the dynamic magnet includes multiple parallel bar magnets. When the magnetic field range shrinks, the outer magnet moves parallel to the inner magnet. When the magnetic field range expands, the outer magnet moves parallel to the inner magnet.

[0012] More preferably, the outer magnets are arranged in a ring, and the inner magnet is located at the center of the outer magnets. When the magnetic field range shrinks, the outer magnets move towards the inner magnets along the radius of the rings. When the magnetic field range expands, the outer magnets move away from the inner magnets along the radius of the rings.

[0013] More preferably, the gas supply ring is fitted outside the moving target, and the reactive gas flows out from the gas supply ring.

[0014] More preferably, the air supply ring and the moving target are coaxial.

[0015] More preferably, the reaction gas is one or more of argon or the gas required for magnetron sputtering reaction.

[0016] More preferably, the diameter of the deposition substrate is larger than the diameter of the moving target.

[0017] More preferably, the deposition substrate and the moving target are disposed in a vacuum chamber.

[0018] In summary, the technical solutions conceived by this invention have the following beneficial effects compared with the prior art:

[0019] 1. This invention achieves magnetic field range adjustment by shrinking or expanding the magnet. Since the plasma generated by sputtering on the target surface is confined by the magnetic field, the plasma distribution range can be controlled, thereby changing the size of the deposition spot of target material atoms on the substrate.

[0020] 2. The present invention provides a gas supply ring that surrounds the target material to supply the argon gas required for sputtering. Compared with the traditional gas inlet set on the cavity wall, this arrangement increases the argon atom concentration near the target surface, which is conducive to the sputtering reaction. It overcomes the problems of uneven argon gas distribution in the cavity and low argon atom concentration near the target surface in traditional large-area thin film deposition, which makes it impossible to stably maintain glow discharge.

[0021] 3. This invention can control the film thickness at different positions on a large-area substrate by adjusting the sputtering time of each region by combining the moving speed and rotation speed, based on the periodic rotation characteristics of the substrate and the linear reciprocating motion of the moving target, thereby preparing highly uniform films and films with varying thicknesses. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a magnetron system structure for large-area thin film preparation constructed according to a preferred embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram illustrating the coordination between the linear motion of the moving target and the contraction and expansion states of the dynamic magnet, constructed according to a preferred embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of deposition spots formed on a substrate in the contraction and expansion states of a dynamic magnet constructed according to a preferred embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the structure of a dynamic magnet constructed according to a preferred embodiment of the present invention. In all the figures, the same reference numerals are used to denote the same elements or structures, wherein:

[0026] 10-Deposition substrate, 20-Small deposition spot, 21-Large deposition spot, 100-Moving target, 110-Gas supply ring, 120-Outer magnet, 130-Inner magnet, 140-Target material. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Please see Figure 1 The present invention proposes a magnetron sputtering system for large-area thin film preparation. The system includes a deposition substrate 10 and a moving target 100. The deposition substrate 10 rotates around a central axis with an adjustable speed. The moving target 100 consists of a gas supply ring 110, a target material 140, and a dynamic magnet. The moving target 100 moves linearly along the radial direction of the substrate with an adjustable speed. The gas supply ring 110 is coaxial with the moving target 100 and is supplied with argon gas or reactive gas required for sputtering. The dynamic magnet includes an outer magnet 120 and an inner magnet 130. The outer magnet 120 can continuously contract or expand.

[0029] like Figure 2 As shown, when the outer magnet 120 is in a contracted state, the target surface discharge range is small, forming a small deposition spot 20 on the deposition substrate 10. When the moving target 100 moves upward, the outer magnet 120 moves outward away from the inner magnet, expanding the target surface discharge range and forming a large deposition spot 21 on the deposition substrate 10. The rotation of the deposition substrate 10 and the linear motion of the moving target 100 allow the deposition spot to completely scan the surface of the deposition substrate. Adjusting the rotation speed and moving speed controls the position of the deposition spot and the deposition time, thereby achieving uniform deposition of a large-area thin film. Figure 3 As shown in the figure, when the moving target moves along the radial direction from the position opposite the center of the substrate, the outer magnet gradually expands outward and the deposition spot gradually increases in size. The further away from the center, the larger the area to be deposited on the substrate. The gradually increasing deposition spot of the present invention just meets this requirement. This deposition method makes the deposition spot coverage area of ​​the outer edge of the substrate larger in a single linear motion, thereby improving the uniformity of multiple depositions.

[0030] The deposition substrate 10 can be moved along the central axis to adjust the substrate-target spacing, and the rotation speed of the deposition substrate 10 is adjustable within one rotation cycle.

[0031] The linear reciprocating motion of the moving target 100 includes uniform speed, uniform speed change, variable acceleration, and variable deceleration.

[0032] The gas supply ring 110 is distributed around the target 140, and the gas introduced includes argon and the gas required for reactive sputtering.

[0033] The external magnet 120 can continuously contract or expand to control the area of ​​the target sputtering region, thereby continuously adjusting the size of the deposition spot.

[0034] like Figure 4 As shown, in one embodiment of the present invention, the outer magnet 120 is arranged in a ring, and the inner magnet 130 is disposed at the center of the outer magnet. When the magnetic field range shrinks, the outer magnet 120 moves towards the inner magnet 130 along the radius of the ring. When the magnetic field range expands, the outer magnet 120 moves away from the inner magnet 130 along the radius of the ring.

[0035] Large-area thin films are prepared based on the above-mentioned magnetocontrol system for large-area thin film preparation; wherein, the deposition position is controlled by adjusting the periodic rotation characteristics of the substrate 10 rotation process and the linear reciprocating motion of the moving target 100, and its rotation speed and moving speed determine the deposition thickness of different regions.

[0036] The specific implementation steps of the magnetic control system of the present invention are as follows:

[0037] S1, fix the deposition substrate, set the deposition temperature, and build the high vacuum environment required for magnetron sputtering.

[0038] S2 sets the periodic rotation characteristics of the deposition substrate.

[0039] S3: Set the initial position of the moving target and preset its linear reciprocating motion mode.

[0040] S4, adjust the initial position of the dynamic magnet so that the moving target and the magnet work together to construct the desired deposition area.

[0041] S5, turn on the target power supply, and after the predetermined sputtering time, a large-area thin film is prepared.

[0042] The moving target 100 and the outer magnet 120 are coordinated as follows: when the moving target 100 moves toward the center of the substrate, the outer magnet 120 contracts and expands outward, which allows the deposition area to change continuously with the substrate radius, thus achieving uniform deposition of large-area thin films.

[0043] This invention adjusts the position of the discharge region by rotating the substrate and moving the target linearly, so that the deposition spot can cover a large area of ​​the substrate, enabling the fabrication of large-area thin films with a small magnetron sputtering target. The dynamic magnet contracts and expands outward with the position of the moving target. When the moving target is coaxial with the substrate, the outer magnet contracts and gradually expands outward as it moves along the radial direction of the substrate, thereby increasing the area of ​​the deposition spot towards the edge of the substrate. This adapts to the deposition of thin films on circular substrates and can significantly improve the uniformity of large-area coatings.

[0044] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A magnetron system for large-area thin film fabrication, characterized in that, The magnetron sputtering system includes a deposition substrate (10) and a moving target (100), wherein, The deposition substrate (10) is disposed opposite to the moving target (100). The deposition substrate (10) can rotate around its own center. The moving target (100) includes a target material (140), a gas supply ring (110), and a dynamic magnet. The target material (140) is disposed at the top of the moving target (100). The target material (140) is connected to the electric field cathode so that the target material (140) serves as the cathode target (140) for magnetron sputtering. The gas supply ring (110) is used to provide reactive gas to the area around the target material (140). The dynamic magnet is disposed in the moving target (100) and is used to provide an adjustable magnetic field around the target material (140). When the center of the moving target (100) is on the same horizontal line as the center of the deposition substrate (10), the magnetic field range is the smallest, and the deposition spot area formed on the deposition substrate (10) is the smallest. When the moving target (100) moves away from the center of the deposition substrate (10) along the radial direction of the deposition substrate (10), the magnetic field range gradually increases, and the deposition spot area formed on the deposition substrate (10) gradually increases. During the magnetron sputtering deposition process, the rotation of the deposition substrate (10) and the movement of the moving target (100) enable the deposition spot to completely scan the surface of the deposition substrate (10). The rotation speed and moving speed are adjusted to control the position of the deposition spot and the deposition time, thereby achieving uniform deposition of a large area thin film. By adjusting the position of the discharge region through substrate rotation and linear motion of the moving target, the deposition spot can cover a large area of ​​the substrate, enabling the fabrication of large-area thin films using a small magnetron sputtering target. The dynamic magnet contracts and expands outward with the position of the moving target. When the moving target is coaxial with the substrate, the outer magnet contracts, and when it moves along the radial direction of the substrate, it gradually expands outward, thereby increasing the area of ​​the deposition spot towards the edge of the substrate. This adapts to the deposition of thin films on circular substrates and can significantly improve the uniformity of large-area coatings. The dynamic magnet includes an inner magnet (130) and an outer magnet (120). The inner magnet (130) is fixed at the center of the moving target (100). The outer magnet (120) moves away from the inner magnet (130) as the moving target (100) moves away from the center of the deposition substrate (10) along the radial direction of the deposition substrate (10), thereby gradually increasing the magnetic field range. The inner magnet (130) and the outer magnet (120) have opposite magnetic pole directions. When the magnetic field range shrinks, the distance between the inner magnet (130) and the outer magnet (120) decreases. When the magnetic field range expands, the distance between the inner magnet (130) and the outer magnet (120) increases. The outer magnet (120) is arranged in a ring, and the inner magnet (130) is located at the center of the outer magnet (120). When the magnetic field range shrinks, the outer magnet (120) moves towards the inner magnet (130) along the radius of the ring. When the magnetic field range expands, the outer magnet (120) moves away from the inner magnet (130) along the radius of the ring.

2. The magnetron sputtering system for large-area thin film fabrication as described in claim 1, characterized in that, The dynamic magnet includes multiple parallel bar magnets. When the magnetic field range shrinks, the outer magnet (120) moves parallel towards the inner magnet (130). When the magnetic field range expands, the outer magnet (120) moves parallel away from the inner magnet (130).

3. A magnetron system for large-area thin film fabrication as described in claim 1 or 2, characterized in that, The gas supply ring (110) is fitted outside the moving target (100), and the reaction gas flows out from the gas supply ring (110).

4. The magnetron sputtering system for large-area thin film fabrication as described in claim 3, characterized in that, The gas supply ring (110) and the moving target (100) are coaxial.

5. A magnetron system for large-area thin film fabrication as described in claim 1 or 2, characterized in that, The reaction gas is one or more of argon or the gas required for magnetron sputtering reaction.

6. The magnetron sputtering system for large-area thin film fabrication as described in claim 1, characterized in that, The diameter of the deposition substrate (10) is larger than the diameter of the moving target (100).

7. The magnetron sputtering system for large-area thin film fabrication as described in claim 1, characterized in that, The deposition substrate (10) and the moving target (100) are arranged in a vacuum chamber.

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