Method for improving utilization rate of magnetron sputtering target material
By using the method of changing the magnetic flux by magnetically enhanced sputtering equipment and backplate in magnetron sputtering technology, the problem of low utilization rate of sputtering targets is solved, and the effect of improving target utilization rate and stability is achieved.
Patent Information
- Application Number
- CN202510116278.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-04-25
AI Technical Summary
In the existing magnetron sputtering technology, the utilization rate of sputtering targets is low, especially the utilization rate of precious metal-containing targets, resulting in high costs and increased equipment downtime required for frequent target replacement.
Using a magnetically enhanced sputtering device, the first surface of the sputtering target is sputtered and the second surface is electrically in contact with the cathode of the device. When the erosion trajectory on the first surface reaches a predetermined depth, the sputtering target is flipped, so that the second surface becomes a sputtering surface, and the magnetic flux is changed through the back plate to form a transversely offset second erosion trajectory.
It effectively improves the utilization rate of sputtering targets, reduces the need for frequent target replacement, reduces the cost, and improves the target stability during sputtering.
Smart Images
Figure CN119876877A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of magnetron sputtering, and in particular to a method for improving the utilization rate of magnetron sputtering target materials. Background Art
[0002] Magnetic and MO recording media are widely used, especially in the computer industry. Magnetic media in the form of disks used in computer-related applications typically include a non-magnetic metal substrate, an aluminum (Al)-based alloy such as aluminum-magnesium (Al-Mg), having at least one major surface on which a stack of layers comprising a plurality of thin film layers constituting the media is sequentially deposited. Such layers may include, in order from the substrate surface, electroplated layers, which typically include: an electroplated layer of amorphous nickel phosphorus (NiP), a polycrystalline underlayer, an electroplated layer of chromium (Cr) or a Cr-based alloy, a magnetic layer, an electroplated layer of a cobalt (Co)-based alloy, and a protective overcoat, typically carbon (C) or carbon doped with at least one of hydrogen (H), nitrogen (N), and fluorine (F).
[0003] According to conventional manufacturing methods, most layers are deposited by cathode sputtering. A similar situation exists in the manufacture of magneto-optical (MO) media, where a layer stack comprising multiple thin film layers, such as alloy layers with reflective or thermomagnetic properties (e.g., TbFeCo, etc.) for use as write, write assist and read layers, is sequentially sputter-deposited on a suitable substrate surface.
[0004] Before sputtering deposition, the substrate, i.e., the surface of the sputtering target, needs to be eroded to form an erosion track. The traditional method generally etches a single side of the sputtering target. When double-sided etching is performed, the sputtering target may be penetrated due to overlapping erosion tracks, causing the sputtering target to fail. In order to improve the utilization rate of the sputtering target, especially the utilization rate of the target containing precious metals, it is necessary to improve the utilization rate of magnetron sputtering target materials. Summary of the invention
[0005] The purpose of the present invention is to solve the shortcomings in the prior art and to propose a method for improving the utilization rate of magnetron sputtering target materials.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions:
[0007] A method for improving the utilization rate of magnetron sputtering target material comprises the following steps:
[0008] Step 1: sputtering a first surface of a sputtering target using a magnetically enhanced sputtering device, and electrically contacting a second surface of the sputtering target with a cathode of the magnetically enhanced sputtering device;
[0009] Step 2, when the first erosion track on the first surface of the sputtering target reaches a predetermined depth, taking out the sputtering target from the magnetic enhanced sputtering device;
[0010] Step 3, flipping the sputtering target and installing it in the magnetic enhanced sputtering device, so that the second surface is the sputtering surface, the first surface is the opposite surface, the first surface is in electrical contact with the cathode of the magnetic enhanced sputtering device through the back plate, the magnetic flux is changed through the back plate through the channel of the sputtering target, and a second erosion track is sputtered in a specified area of the second surface;
[0011] Step 4: Form a second erosion track with a transverse offset on the second surface of the sputtering target by means of a magnetically enhanced sputtering device and reach a predetermined depth.
[0012] Preferably, the backing plate is composed of at least one material capable of forming a second erosion track laterally offset from the first erosion track of the sputtering target during sputtering on the second surface of the sputtering target, and an annular protrusion in contact with the end of the first erosion track is provided on the backing plate, through which the magnetic field is guided to the second erosion track.
[0013] Preferably, the sputtering target is composed of a material for forming a thin film layer of a magnetic or magneto-optical recording medium, and the material is selected from one of a non-magnetic metal element, a non-magnetic alloy, a magnetic metal element, a magnetic alloy, a dielectric, a thermomagnetic alloy, carbon, and a carbon compound.
[0014] Preferably, the backing plate is composed of a material that alters the passage of magnetic flux through the sputtering target.
[0015] Preferably, the back plate is composed of Cr or CoCr alloy.
[0016] Preferably, the thickness of the back plate is 0.3 cm-3.5 cm.
[0017] Preferably, a first shielding layer is provided on the vertical end surface of the raised portion opposite to the curved surface.
[0018] Preferably, a second shielding layer is provided on the upper end surface of the back plate, and the second shielding layer is connected to the first shielding layer.
[0019] Preferably, when the second erosion track is located inside the protrusion, the second shielding layer is located outside the protrusion.
[0020] Preferably, when the second erosion track is located outside the protrusion, the second shielding layer is located inside the protrusion.
[0021] The beneficial effects of the present invention are:
[0022] 1. Compared with the traditional sputtering method, the sputtering method proposed in the present invention flips the sputtering target after the first surface of the sputtering target is sputtered, changes the magnetic flux, and then sputters the second surface of the sputtering target. Compared with the traditional single-sided sputtering, the utilization rate of the sputtering target is effectively improved.
[0023] 2. The raised portion on the back plate cooperates with the first shielding layer and the second shielding layer to pass the magnetic flux through the channel of the sputtering target, thereby forming a second erosion track in the designated area of the sputtering target. On the other hand, the raised portion can reduce the displacement of the sputtering target and improve the stability of the sputtering target during the sputtering process.
[0024] 3. The present invention advantageously provides a methodology and apparatus for obtaining significantly increased utilization and life of sputtering targets used in magnetically assisted sputtering, thereby achieving significant cost reductions and reduced equipment downtime required for frequent target replacement. The method and apparatus of the present invention are particularly applicable when the sputtering target is composed of expensive materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 A schematic diagram of the cross-sectional structure of a magnetically enhanced sputtering device in a method for improving the utilization rate of magnetron sputtering targets proposed by the present invention Figure 1 ;
[0026] Figure 2 A schematic diagram of the cross-sectional structure of a magnetically enhanced sputtering device in a method for improving the utilization rate of magnetron sputtering targets proposed by the present invention Figure 2 ;
[0027] Figure 3 A schematic diagram of the cross-sectional structure of a back plate in a method for improving the utilization rate of magnetron sputtering targets proposed by the present invention Figure 1 ;
[0028] Figure 4 A schematic diagram of the cross-sectional structure of a back plate in a method for improving the utilization rate of magnetron sputtering targets proposed by the present invention Figure 2 .
[0029] In the figure: 1 sputtering target, 2 first surface of sputtering target, 3 second surface of sputtering target, 4 magnetic sheet, 5 magnetic shunt, 6 cathode, 7 power supply, 8 first erosion track, 9 back plate, 10 second erosion track, 91 raised portion, 92 first shielding layer, 93 second shielding layer. DETAILED DESCRIPTION
[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.
[0031] Reference Figure 1-4 , a method for improving the utilization rate of magnetron sputtering target material, comprising the following steps:
[0032] Step 1: sputtering the first surface 2 of the sputtering target using a magnetically enhanced sputtering device, and electrically contacting the second surface 3 of the sputtering target with the cathode 6 of the magnetically enhanced sputtering device;
[0033] Step 2, when the first erosion track 8 on the first surface 2 of the sputtering target reaches a predetermined depth, taking out the sputtering target 1 from the magnetic enhanced sputtering equipment;
[0034] Step 3, the sputtering target 1 is turned over and installed in the magnetic enhanced sputtering device, so that the second surface 3 is the sputtering surface, the first surface 1 is the opposite surface, the first surface 1 is electrically in contact with the cathode 6 of the magnetic enhanced sputtering device through the back plate 9, the back plate 9 changes the channel of the magnetic flux passing through the sputtering target, and sputtering is performed in a specified area of the second surface 3 to form a second erosion track 10;
[0035] Step 4: forming a second erosion track 10 with a laterally offset shape on the second surface 3 of the sputtering target by means of a magnetically enhanced sputtering device and reaching a predetermined depth.
[0036] The backing plate 9 is composed of at least one material that can form a second erosion track 10 that is laterally offset from the first erosion track 8 of the sputtering target during sputtering on the second surface 3 of the sputtering target, and a protrusion 91 that contacts the end of the first erosion track 8 is provided on the backing plate, and the magnetic field is guided to the second erosion track 10 through the annular protrusion 91.
[0037] The sputtering target 2 is composed of a material for forming a thin film layer of a magnetic or magneto-optical recording medium, and the material is selected from a non-magnetic metal element, a non-magnetic alloy, a magnetic metal element, a magnetic alloy, a dielectric, a thermomagnetic alloy, carbon, and a carbon compound.
[0038] The back plate 9 is composed of a material that changes the passage of magnetic flux through the sputtering target; the back plate 9 is composed of Cr or CoCr alloy; the thickness of the back plate is 0.3 cm-3.5 cm.
[0039] A first shielding layer 92 is disposed on a vertical end surface of the protruding portion 91 opposite to the curved surface.
[0040] A second shielding layer 93 is disposed on the upper end surface of the back plate 9 , and the second shielding layer 93 is connected to the first shielding layer 92 .
[0041] When the second erosion track 10 is located inside the protrusion 91, the second shielding layer 93 is located outside the protrusion 91. Figure 3 shown.
[0042] When the second erosion track 10 is located outside the protrusion 92, that is, Figure 2 The positions of the first erosion track 8 and the second erosion track 10 are exchanged, and the second shielding layer 93 is located inside the protrusion 91, such as Figure 4 shown.
[0043] refer to Figure 1, which shows a cross-sectional view of a simplified magnetically enhanced sputtering device, showing the basic structural features and operating principles of a conventional magnetically enhanced sputtering device, wherein a first erosion track 8 is formed in a first surface 2 of a sputtering target. According to the illustrated embodiment, a sputtering target 1 is placed on the magnetically enhanced sputtering device, the sputtering target 1 having a relatively flat first surface 2 and a second surface 3, the first surface 2 of the sputtering target being oriented upward for sputtering therefrom, the second surface 3 of the sputtering target facing and electrically contacting a cathode 6 via a plurality of spaced apart magnetic sheets 4, and electrically connected to a power source 7 (the power source 7 may be a DC power source or an RF power source). The magnetically enhanced sputtering device also includes a magnetic shunt 5 for directing the magnetic flux provided by the magnetic sheets 4 along a desired path for achieving sputtering of the target surface 2 facing upward.
[0044] Magnetic flux lines from a magnetic sheet 4 of a first polarity located below the sputtering target 1 enter the sputtering target 1 and arch over the upward sputtering target first surface 2 before exiting the sputtering target 1 and then returning to a second magnetic sheet 4 of opposite polarity located below the target 1 to create a closed loop "racetrack" where the sputtering plasma is concentrated. Positions above the upward sputtering target first surface 2, where the magnetic flux lines running between the magnetic poles of opposite polarity are generally parallel thereto, correspond to positions in the sputtering target first surface 2 where maximum sputtering, and therefore maximum erosion, occurs, and substantially less erosion occurs at positions where the magnetic flux lines deviate from parallelism with the sputtering target first surface 2. The result is the formation of a first erosion track 8, a first erosion track 8, in the upward sputtering target first surface 2.
[0045] Reference Figure 2 According to the next step of the present invention, a backing plate 9 made of a selected erosion track displacement (or replacement) material is mounted on the sputtering target first surface 2 of the sputtering target 1 having a first erosion track 8 formed therein, and the sputtering target 1 is remounted in the magnetically enhanced sputtering apparatus so that its sputtering target second surface 3 is oriented upward for sputtering therefrom, and the sputtering target first surface 2 faces and is in electrical contact with the cathode electrode 6 via the backing plate 9 and the magnetic sheet 4.
[0046] The present invention advantageously promotes maximum utilization of both surfaces of the sputtering target 1 without creating the possibility of target failure, such as penetration due to overlapping erosion tracks. The advantages of increased target utilization provided by the present invention are particularly significant when the sputtering target 1 is composed of expensive materials, such as precious metals and rare earth metals.
[0047] The backing plate 9 is preferably constructed of a material that influences, ie, modifies, the passage of magnetic flux through the target 1, the composition and thickness of the backing plate being selected to obtain the desired laterally spaced second eroded tracks 10 on the second surface 2 of the sputtering target.
[0048] By way of illustration, but not limitation, back plate 9 may be composed of Cr or CoCr alloy, for example, wherein the Cr content ranges from 0 to about 100.
[0049] The sputtering target 1 is composed of a material for forming a thin film layer of a magnetic or magneto-optical (MO) recording medium, for example, a material selected from the group consisting of nonmagnetic metals or alloys, magnetic metals or alloys, dielectrics, thermomagnetic alloys, and carbon or carbon compounds.
[0050] Compared with the traditional sputtering method, the sputtering method proposed in the present invention flips the sputtering target 1 after the first surface 2 of the sputtering target 1 is sputtered, changes the magnetic flux, and then sputters the second surface 3 of the sputtering target. Compared with the traditional single-sided sputtering, the utilization rate of the sputtering target 1 is effectively improved.
[0051] The raised portion 91 on the back plate 9 cooperates with the first shielding layer 92 and the second shielding layer 93 to pass the magnetic flux through the channel of the sputtering target, thereby forming a second erosion track 10 in a designated area of the sputtering target. On the other hand, the raised portion 91 can reduce the displacement of the sputtering target 1 and improve the stability of the sputtering target 1 during the sputtering process.
[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A method for improving the utilization rate of magnetron sputtering target material, characterized in that: The following steps are involved: Step 1: sputtering a first surface of a sputtering target using a magnetically enhanced sputtering device, and electrically contacting a second surface of the sputtering target with a cathode of the magnetically enhanced sputtering device; Step 2, when the first erosion track on the first surface of the sputtering target reaches a predetermined depth, taking out the sputtering target from the magnetic enhanced sputtering device; Step 3, flipping the sputtering target and installing it in the magnetic enhanced sputtering device, so that the second surface is the sputtering surface, the first surface is the opposite surface, the first surface is in electrical contact with the cathode of the magnetic enhanced sputtering device through the back plate, the magnetic flux is changed through the back plate through the channel of the sputtering target, and a second erosion track is sputtered in a specified area of the second surface; Step 4: Form a second erosion track with a transverse offset on the second surface of the sputtering target by means of a magnetically enhanced sputtering device and reach a predetermined depth.
2. A method for improving the utilization rate of magnetron sputtering targets according to claim 1, characterized in that: The backing plate is composed of at least one material capable of forming a second erosion track laterally offset from the first erosion track of the sputtering target during sputtering on the second surface of the sputtering target, and an annular protrusion is provided on the backing plate to contact the end of the first erosion track, through which the magnetic field is guided to the second erosion track.
3. The method for improving the utilization rate of magnetron sputtering target according to claim 1, characterized in that: The sputtering target is composed of a material for forming a thin film layer of a magnetic or magneto-optical recording medium, and the material is selected from a non-magnetic metal element, a non-magnetic alloy, a magnetic metal element, a magnetic alloy, a dielectric, a thermomagnetic alloy, carbon, and a carbon compound.
4. The method for improving the utilization rate of magnetron sputtering target according to claim 1, characterized in that: The backing plate is composed of a material that alters the passage of magnetic flux through the sputtering target.
5. The method for improving the utilization rate of magnetron sputtering target according to claim 3, characterized in that: The back plate is composed of Cr or CoCr alloy.
6. The method for improving the utilization rate of magnetron sputtering target according to claim 3, characterized in that: The thickness of the back plate is 0.3cm-3.5cm.
7. A method for improving the utilization rate of magnetron sputtering targets according to any one of claims 1 to 6, characterized in that: A first shielding layer is arranged on the vertical end surface of the protruding portion opposite to the curved surface.
8. The method for improving the utilization rate of magnetron sputtering target according to claim 7, characterized in that: A second shielding layer is disposed on the upper end surface of the back plate, and the second shielding layer is connected to the first shielding layer.
9. The method for improving the utilization rate of magnetron sputtering target according to claim 8, characterized in that: When the second erosion track is located inside the protrusion, the second shielding layer is located outside the protrusion.
10. The method for improving the utilization rate of magnetron sputtering target according to claim 8, characterized in that: When the second erosion track is located outside the protrusion, the second shielding layer is located inside the protrusion.