Sputtering trap with multimodal particle size distribution

Abstract

The invention relates to a sputter well with a multimodal particle size distribution. Sputtering wells formed on at least a portion of a sputtering chamber component having a plurality of particles and a particle size distribution profile with at least two different distributions are disclosed. Methods of forming a sputter well having a particle size distribution profile with at least two different distributions are also provided.

Description

[0001] This application is a divisional application of the invention patent application with application date of December 4, 2017, application number 201780074169.3, and name “Sputtering trap with multi-peak particle size distribution”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Patent Application No. 15 / 824,802, filed on November 28, 2017, and also claims priority to Provisional Application No. 62 / 434,673, filed on December 15, 2016, both of which are incorporated herein by reference in their entirety. Technical Field

[0004] The present disclosure relates to sputtering traps or particle traps for use on sputtering chamber components and methods of making the same. More particularly, the present disclosure relates to sputtering traps having a multimodal particle distribution. Background Art

[0005] Physical vapor deposition ("PVD") processes can be used to form a film or layer of material on a substrate surface. PVD processes can be used, for example, in semiconductor manufacturing processes to form metallization layers during the manufacture of integrated circuit structures and devices. Sputtering deposition is a PVD process in which a glow plasma discharge bombards a sputtering target, which releases atoms that are subsequently deposited onto a substrate.

[0006] Figure 1 , a schematic diagram of a portion of an exemplary sputtering deposition apparatus 8 is shown. In one configuration, a sputtering target assembly 10 includes a backing plate 12 having a target 14 bonded thereto. A substrate 18, such as a semiconductor material wafer, is within the sputtering deposition apparatus 8 and is disposed spaced from the target 14. As shown, the target 14 is disposed on the substrate 18 and is positioned such that the sputtering surface 16 faces the substrate 18.

[0007] In operation, sputtered material 22 is displaced from surface 16 of target 14 and forms thin film 20 on substrate 18. In some embodiments, suitable substrates 18 include wafers used in semiconductor manufacturing. For example, target 14 is bombarded with energy until atoms from surface 16 are released into the surrounding atmosphere and subsequently deposited on substrate 18. In some embodiments, plasma sputtering is used to deposit thin metal films onto chips or wafers for use in electronic devices.

[0008] If particles are formed, problems may arise during the deposition process because these particles may fall into or onto the deposited film and destroy the desired properties of the film. A sputtering trap or particle trap may be included on the sputtering target to capture particles formed during the deposition process. In addition, there is still a risk that the captured particles may peel off the sputtering target and destroy the film. For example, loosely held particles may peel off from the sputtering trap during cyclic thermal stress. Therefore, it is desirable to develop a sputtering trap or particle trap that can be applied to sputtering components such as sputtering targets, which captures and holds particles formed during the deposition process. Capturing and holding such particles reduces the likelihood of particles falling onto the deposited film during the deposition process. Summary of the invention

[0009] In some embodiments, a sputtering target assembly includes a front surface, a rear surface opposite the front surface, a sputtering surface on at least a portion of the front surface, a flange extending radially from the sputtering surface, and a sputtering well formed on at least a portion of the front surface of the flange. The sputtering well includes a plurality of particles and has a particle size distribution curve with at least two different distributions.

[0010] In some embodiments, a method of forming a sputtering well on a sputtering target assembly includes attaching particles to at least a portion of the sputtering target assembly by a cold spray technique or a thermal spray technique. The particle size distribution curve of the attached particles has at least two different distributions.

[0011] In some embodiments, a sputtering well is formed on at least a portion of a sputtering chamber component. The sputtering well includes a plurality of particles having a particle size distribution profile with at least two different distributions.

[0012] While multiple embodiments are disclosed, other embodiments of the present invention will be apparent to those skilled in the art from the following detailed description which shows and describes illustrative embodiments of the present invention.Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of a portion of a physical vapor deposition apparatus.

[0014] Figure 2 is a schematic top view of an exemplary sputtering target assembly.

[0015] Figure 3 It is along Figure 2 Schematic cross-sectional view along line 3-3.

[0016] Figure 4 is an exemplary particle size distribution graph of a sputtering well having a bimodal particle size distribution.

[0017] Figure 5 is an image witnessing the multi-peak sputtering trap of the sample.

[0018] Figure 6 is a scanning electron microscope micrograph of a sputtered well after bead blasting.

[0019] Figure 7 is a scanning electron microscope micrograph of a multimodal sputtering well.

[0020] Figure 8 It is the energy dispersive X-ray spectroscopy (EDS) curve of pure titanium powder. DETAILED DESCRIPTION

[0021] The present disclosure relates to sputtering traps or particle traps used on PVD equipment components and methods for making the same. In some embodiments, the PVD equipment component is a sputtering target used in a PVD sputtering chamber. However, those skilled in the art will recognize that the sputtering trap can be formed on any component of a physical vapor deposition equipment where particles become a problem.

[0022] Figure 2 is a top view of the sputtering target assembly 30, and Figure 3 It is along Figure 2 3-3 of the sputtering target assembly 30. The sputtering target assembly 30 includes a sputtering target 31 and a backing plate 34. In some embodiments, the sputtering target 31 and the backing plate 34 have a circular or substantially circular cross-sectional shape in the top view. In use, the backing plate 34 is connected to the sputtering deposition equipment, for example, by bolts or clamps.

[0023] The sputtering target 31 has a front surface or sputtering surface 32, a rear surface 29 opposite the sputtering surface 32, and a sidewall 35 extending between the sputtering surface 32 and the rear surface around the circumference of the sputtering target 31. In some embodiments, the sputtering surface 32 can be substantially flat or planar. For example, the sputtering surface 32 can be parallel to a horizontal first plane. In other embodiments, the sputtering surface 32 can have one or more convex or concave portions or features. In addition or alternatively, the rear surface of the sputtering target 31 can be substantially planar. Alternatively, the rear surface can have a protrusion or recess. For example, the rear surface can receive a portion of the backing plate 34 or be received within a portion of the backing plate 34, which is a design known as an embedded backing plate.

[0024] The sputtering target 31 may be formed of any metal suitable for a PVD deposition process. For example, the sputtering target 31 may include aluminum (Al), vanadium (V), niobium (Nb), copper (Cu), titanium (Ti), tantalum (Ta), tungsten (W), ruthenium (Ru), germanium (Ge), selenium (Se), zirconium (Zr), molybdenum (Mo), hafnium (Hf) and alloys thereof such as Al alloys, V alloys, Nb alloys, Cu alloys, Ti alloys, Ta alloys, W alloys, Ru alloys, Ge alloys, Se alloys, Zr alloys, Mo alloys, and Hf alloys. Suitable alloys include, but are not limited to, copper-manganese (CuMn) alloys, aluminum-copper (AlCu) alloys, titanium-tungsten (TiW) alloys, tantalum-aluminum (TaAl) alloys, and ruthenium (Ru) alloys.

[0025] The backing plate 34 has a front surface 37, a rear surface 39 opposite the front surface 37, and a sidewall 41 extending from the front surface 37 to the rear surface 39 around the outer circumference of the backing plate 34. The rear surface of the sputtering target 31 is adjacent to and bonded to the front surface 37 of the backing plate 34. The radius of the backing plate 34 is greater than the radius of the sputtering target 31, so that at least a portion of the backing plate 34 (referred to as a flange 44) extends radially outward from the outer diameter or radial edge of the sputtering target 31. In some embodiments, the backing plate 34 can be formed of the same material as the sputtering target 31. For example, the backing plate 34 and the sputtering target 31 can be part of a monolithic or monolithic sputtering target assembly 30. In other embodiments, the backing plate 34 and the sputtering target 31 can be separate pieces that are bonded together. In such embodiments, the backing plate 34 can be formed of the same or different material as the sputtering target 31.

[0026] The flange 44 extending radially outward from the sputtering target 31 can be substantially flat or planar. In some embodiments, the exposed portion of the front surface 37 can be parallel or substantially parallel to a horizontal plane. In other embodiments, the exposed portion of the front surface 37 can be in a plane that is at an angle to the first plane. The flange 44 can include one or more countersunk holes and / or through holes 45 for connecting or bolting the backing plate 34 to a sputtering deposition source or apparatus.

[0027] The back plate 34 may be formed of any suitable metal. For example, the back plate 34 may include aluminum (Al), vanadium (V), niobium (Nb), copper (Cu), titanium (Ti), tantalum (Ta), tungsten (W), ruthenium (Ru), germanium (Ge), selenium (Se), zirconium (Zr), molybdenum (Mo), hafnium (Hf) and alloys and combinations thereof. For example, alloys include Al alloys, V alloys, Nb alloys, Cu alloys, Ti alloys, Ta alloys, W alloys, Ru alloys, Ge alloys, Se alloys, Zr alloys, Mo alloys and Hf alloys. Suitable alloys include, but are not limited to, copper-manganese (CuMn) alloys, aluminum-copper (AlCu) alloys, titanium-tungsten (TiW) alloys, tantalum-aluminum (TaAl) alloys and ruthenium (Ru) alloys. In some embodiments, the back plate 34 and the sputtering target 31 may be formed of the same material. In other embodiments, the back plate 34 and the sputtering target 31 may be formed of different materials.

[0028] The backing plate 34 also includes a sputtering well 46 formed on the front surface 37 of the flange 44. In some embodiments, the sputtering well 46 can extend from where the sidewall of the sputtering target 31 contacts the front surface 34 of the backing plate 37. For example, the sputtering well 46 can extend radially around the circumference of the sputtering target 31. In some embodiments, the back surface of the target 31 can have an outer radius r1, and the sputtering well 46 can have an inner radius r1 and an outer radius r2. For example, the sputtering well 46 can be formed proximate to where the target 31 is joined to the backing plate 34. In addition or alternatively, the sputtering well can be formed on the sidewall 35 of the sputtering target 31.

[0029] As discussed herein, particle formation during the sputtering process becomes a problem because such particles, if deposited on the substrate, will affect the uniformity of the formed film. Even if the particles are captured or captured in the sputtering trap, the particles are likely to peel off during sputtering deposition. The sputtering trap 46 is configured to capture particles formed during the sputtering deposition process and prevent them from being deposited on the formed film. In addition, the sputtering trap 46 is configured to retain the captured particles. As described herein, the sputtering trap 46 can be formed by spraying and adhering the particles to the backing plate 34 and / or spraying and adhering along the circumference of the sputtering target 31. Particles suitable for forming the sputtering trap 46 include metals and metal alloys, ceramics, carbides and metalloids. Suitable metal and metal alloy particles include titanium and titanium alloys.

[0030] For example, particles can be adhered to flange 44 by a thermal spray process or a cold spray process to form a sputtering trap 46. This process can form particles by a wire source or a powder source. For example, particles can be formed by a wire source by a twin-wire arc spray process, or particles can be formed by a powder using a plasma spray or cold spray process. The particles formed on flange 44 have a particle size distribution. A particle distribution graph is formed by plotting particle size against frequency (i.e., the percentage of particles). In a powder with a symmetrical distribution, the particle distribution graph has a single distribution in the shape of a downwardly open parabola. The particle distribution graph has a single vertex or a single peak, which is equal to the average particle size. For a symmetrical distribution, the mean, median, and mode are equal. The width or breadth of the distribution can be described by the standard deviation or coefficient of variation of the particles.

[0031] The particle size of spherical particles can be described by diameter. Non-spherical particles are often described by the equivalent spherical diameter. The equivalent spherical diameter is determined by measuring a physical property (such as scattered light) and determining the size of the sphere that would produce the measurement.

[0032] The particle size of the particles of sputtering trap 46 can be determined using, for example, a scanning electron microscope (SEM), a laser diffraction particle analyzer, or energy dispersive X-ray spectroscopy (EDS). Sputtering trap 46 has a particle distribution curve graph having at least two different normal distributions, each having an average value. For example, the particle distribution curve graph of the particles of sputtering trap 46 can resemble two partially overlapping parabolas. An exemplary curve graph is shown in FIG. Figure 4 , which has a first mean M1 of the first distribution D1 and a second mean M2 of the second distribution D2. In some embodiments, the particle size distribution curve graph is obtained based on a representative sample area of ​​the sputtering well 46. For example, a particle size distribution curve graph can be created based on four samples of the same size taken at four locations spaced equally around the sputtering well 46.

[0033] The average surface roughness (Ra) of the sputtering well 46 may be at least 5 μm (200 microinches), at least 10 μm (400 microinches), at least 25 μm (1000 microinches), or greater than or equal to 38 μm (1500 microinches). In some embodiments, the Ra of the sputtering well 46 may be from about 15 μm (600 microinches) to about 50 μm (2000 microinches). A surface roughness tester may be used to determine the surface roughness. Suitable surface roughness testers include the Surftest SJ-410 series and the Surftest SJ-201P series, both of which are available from Mitutoyo of Aurora, Illinois.

[0034] The sputtering trap 46 can be formed by adhering particles, such as powder particles, to a textured surface. In some embodiments, the texture can be formed on the sputtering trap 46 before the particles are adhered. For example, the textured surface can be formed by a saw, a knurling device, a computer numerical control (CNC) device, a manual lathe, or other suitable machining tool to form a random or repeating pattern. In some embodiments, a saw can be used to cut into the surface and leave a pattern. Alternatively or in addition, a knurling device can be used to press into the surface of the material and leave a desired pattern.

[0035] In some embodiments, the textured surface can have a height difference of about 14 μm (550 micro inches) to about 30 μm (1150 micro inches), about 19 μm (750 micro inches) to about 29 μm (1125 micro inches), or about 23 μm (900 micro inches) to about 28 μm (1100 micro inches) as measured from maximum height to minimum height. For example, the textured surface can have a height difference of about 13 μm (500 micro inches) to about 18 μm (700 micro inches), about 13.5 μm (525 micro inches) to about 17 μm (675 micro inches), or about 14 μm (550 micro inches) to about 16.5 μm (650 micro inches). In other embodiments, the textured surface may have a height difference of about 24 μm (950 microinches) to about 29 μm (1150 microinches), about 25 μm (975 microinches) to about 28.5 μm (1125 microinches), or about 25.5 μm (1000 microinches) to about 28 μm (1100 microinches).

[0036] In addition or alternatively, a textured surface can be formed by bead blasting. When bead blasting is used, abrasive particles can be sprayed onto the surface, such as along the front surface of the backing plate 34 and / or along the circumference of the sputtering target 31. Abrasive particles suitable for texturing the sputtering well 46 include metal powders, ceramics, carbides, hardened alloys, glass beads, aluminum oxides, zirconium aluminum oxides, silicon carbide, steel sand, steel shot and ceramic beads. Generally speaking, the particles of the bead blasting technology impact the surface to produce textures and are removed from the surface. The particles do not bind or adhere to the surface. Similarly, the knurling process presses the pattern into the surface to produce textures, and machining cuts the pattern into the surface (i.e., removes material) to produce textures. Knurling and machining are not intended to bind or adhere particles to the surface of the sputtering well 46.

[0037] The sputtering well 46 may also be sandblasted before the particles are adhered to the surface of the sputtering well 46. For example, the sputtering well 46 having a textured surface may then be sandblasted before the particles are adhered to the surface of the sputtering well 46. Suitable media for sandblasting include, for example, metal powders, ceramics, carbides, hardened alloys, glass beads, aluminum oxides, zirconium oxides, aluminum oxides, silicon carbide, steel grit, steel shot, and ceramic beads. In some embodiments, the sputtering well 46 may be sandblasted to an Ra of about 2.5 μm (100 micro-inches) to about 15 μm (600 micro-inches). In some embodiments, the sandblasting process may increase the adhesion of particles applied in subsequent processes.

[0038] The sputtering well 46 is formed by adhering or coating particles (such as powder particles or particles from a wire) to a surface. As discussed herein, the sputtering well 46 may be textured and / or sandblasted before the particles are adhered or coated to the surface of the sputtering well 46. In some embodiments, the sputtering well 46 may be subjected to a thermal spraying technique, such as plasma spraying, high velocity oxygen fuel (HVOF) coating. Other methods suitable for adhering particles to the sputtering well 46 include flame spraying techniques or twin wire arc spraying techniques using wires. In some embodiments, the sputtering well 46 may be formed on a target assembly or backing plate by a cold spraying technique, in which a coating material (such as powder particles) is accelerated to a high velocity by a supersonic compressed gas at a temperature below the melting point of the coating material. The resulting coating is a sputtering well 46, which is formed by the accumulation of many sprayed particles.

[0039] The powder particles used to form the sputtering well 46 have a particle distribution curve with at least two peaks. For example, a powder mixture fed to a cold spray device can be formed by mixing two powder compositions having different mesh sizes. The mesh size is the mesh number (U.S. measurement standard) and its relationship to the size of the openings in the mesh and therefore the size of the particles that can pass through these openings. For example, a first powder having a mesh size of 20 μm (635 mesh), 25 μm (500 mesh), 37 μm (400 mesh), or 44 μm (325 mesh) can be combined with a second powder having a mesh size of 210 μm (70 mesh), 74 μm (200 mesh), 88 μm (170 mesh), or 105 μm (140 mesh) to form a powder mixture that is applied to a sputtering target assembly by a cold spray technique, wherein the mesh size of the first powder (corresponding to the smaller opening size) is greater than the mesh size of the second powder (corresponding to the larger opening size) and the mesh sizes of the first powder and the second powder are different. The powders can be combined in equal volume amounts. Alternatively, the powder mixture may contain a larger volume of a larger mesh size powder or a larger volume of a smaller mesh size powder. For example, a powder mixture may be formed by mixing 45 volume % of a first powder and 55 volume % of a second powder. The mesh size and volume of each powder may be selected to obtain the desired surface roughness of the sputtering trap. Suitable mesh sizes and volume contents of the first and second powders for the powder mixture are provided in Table 1.

[0040] Table 1

[0041]

[0042] The powders may be of the same material or of different materials. For example, the first powder and the second powder may be titanium powder. It is also conceivable that a powder mixture is formed by combining three or more powders corresponding to different mesh sizes in equal or unequal volume amounts. In some embodiments, the powder may be of the same type of material as the sputtering target 31. For example, the powder and the sputtering target 31 may be a nickel alloy material.

[0043] Alternatively, the particles can be applied to the backing plate using a thermal spraying technique such as ultra-high velocity (UHV) spraying, high velocity oxygen fuel (HVOF) spraying, plasma flame spraying, twin wire arc spraying, sintering spraying, and wire spraying. In the thermal spraying technique, the coating material is melted or heated and sprayed onto the surface. The coating material can be fed to the thermal spraying device in the form of a powder or a wire. The thermal spraying device heats the coating material to a molten or semi-molten state and accelerates the material toward the flange in the form of micron-sized particles. The resulting coating is a sputtering trap 46 formed by the accumulation of many spraying particles (such as powder particles or molten material).

[0044] In one embodiment, a sputtering well is formed by plasma spraying a powder mixture comprising 44 μm (325 mesh) and 210 μm (70 mesh) titanium powders onto a flange of a sputtering target assembly. In some embodiments, the mixture may comprise from about 50% to about 45% by volume of the 44 μm (325 mesh) titanium powder and from about 50% to about 55% by volume of the 210 μm (70 mesh) titanium powder.

[0045] When the coating material of the thermal spray process is a powder, the coating material can be formed by mixing two or more powder compositions having different mesh sizes as described herein for the cold spray technology. When the coating material of the thermal spray process is in the form of a wire, the thermal spray process is designed or controlled so that the material sprayed from the thermal spray device has a particle size distribution with at least two peaks.

[0046] A sputtering trap formed with one powder will have a particle distribution graph with a single peak (i.e., a unimodal particle size distribution). The sputtering traps disclosed herein are formed with a mixture of two or more powders having different mesh sizes and have a particle distribution graph with two or more different or separate distributions, as shown by a particle distribution graph with two or more peaks (i.e., a multimodal particle size distribution). For example, a sputtering trap formed with a mixture of two powders having different mesh sizes has a particle distribution graph with two separate distributions and two peaks, and a sputtering trap formed with a mixture of three powders having different mesh sizes has a particle distribution graph with three distributions and three peaks.

[0047] A sputtering well with a multi-peak particle size distribution as described herein can reduce the possibility of peeling of a common planarized redeposited film along the sputtering well during a PVD sputtering process, which is a more stressed film according to the geometric effect or roughness effect, Ra of the sputtering well, compared to a non-planarized redeposited film. The multi-peak particle size distribution forms a clustered redeposited film along the sputtering well during the PVD process and helps to reduce the particles that fall from the cyclic thermal stress period. The multi-peak particle size distribution can also reduce the possibility of peeling of loosely held redeposited particles during the cyclic thermal stress period. That is, the multi-peak particle size distribution of the sputtering well can lead to a reduction in particles during the sputtering process.

[0048] The difference in mesh size of a multimodal powder can also form a surface with increased surface roughness compared to a surface formed from only one particle size. For example, a sputtering well formed from a mixture of 210 μm (70 mesh) powder and 44 μm (325 mesh) powder can have a greater surface roughness than a sputtering well formed from only 210 μm (70 mesh) powder or only 44 μm (325 mesh) powder.

[0049] Figure 5is an image of a witness sample sputtering well. The witness sample was sandblasted. After the sandblasting, the side B of the witness sample was plasma sprayed and the bimodal titanium powder particles adhered to the surface of the sputtering well. The titanium powder was formed by mixing titanium powder having a first mesh size and a second mesh size, and the titanium powder was plasma sprayed onto the sputtering well. Figure 5 Large and small particle sizes can be seen in Figure 1. In summary, side A of the witness sample was sandblasted. Side B of the witness sample was sandblasted and then plasma sprayed with bimodal titanium powder.

[0050] Figure 6 is a scanning electron microscope (SEM) micrograph of a sputtered well after bead blasting but before particle adhesion. Figure 7 is a SEM micrograph of a multimodal sputtering well after a plasma spray process in which a bimodal titanium powder adheres to the surface of the sputtering well. The bimodal titanium powder is formed by mixing titanium powders having a first mesh size and a second mesh size. Figure 8 Energy dispersive X-ray spectroscopy (EDS) is used to characterize Figure 7 Elemental analysis graph of high purity bimodal titanium powder.

[0051] Various modifications and additions may be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, although the above embodiments relate to specific features, the scope of the present invention also includes embodiments with different combinations of features and embodiments that do not include all of the above features.

[0052] This application may include the following technical solutions.

[0053] Solution 1. A sputtering target assembly, comprising:

[0054] front surface;

[0055] a rear surface, the rear surface being opposite to the front surface;

[0056] a sputtering surface located on at least a portion of the front surface;

[0057] a flange extending radially from the sputtering surface; and

[0058] A sputtering well is formed on at least a portion of the front surface of the flange, the sputtering well comprising a plurality of particles and having a particle size distribution profile with at least two different distributions.

[0059] Solution 2. A method for forming a sputtering well on a sputtering target assembly, the method comprising:

[0060] combining a first powder having a first mesh size and a second powder having a second mesh size to form a powder mixture comprising a plurality of particles, wherein the first mesh size and the second mesh size are different; and

[0061] The plurality of particles are adhered to at least a portion of the sputtering target assembly by a cold spray technique or a thermal spray technique, wherein a particle size distribution curve of the adhered particles has at least two different distributions.

[0062] Scheme 3. The sputtering target assembly according to Scheme 1 or the method according to Scheme 2, wherein

[0063] The plurality of particles are titanium particles or titanium alloy particles.

[0064] Scheme 4. The sputtering target assembly according to Scheme 1 or the method according to Scheme 2, wherein

[0065] The sputtering well has a surface roughness (Ra) of at least 38 μm.

[0066] Scheme 5. The sputtering target assembly according to Scheme 1 or the method according to Scheme 2, wherein

[0067] The particle size distribution curve has at least three different distributions.

[0068] Option 6. The sputtering target assembly according to Option 1 or the method according to Option 2 further includes:

[0069] A sputtering target is mounted on a backing plate, wherein the backing plate includes the flange.

[0070] Option 7. The sputtering target assembly according to Option 1 or the method according to Option 2, wherein

[0071] The sputtering target assembly is a monolithic sputtering target assembly.

[0072] Scheme 8. The method according to any one of schemes 2 to 7, further comprising:

[0073] The sputtering target assembly is patterned or machined to form a textured surface on at least a portion of the sputtering target assembly, and wherein the particles adhere to at least a portion of the textured surface.

[0074] Scheme 9. The method according to any one of schemes 2 to 8, wherein the first mesh size is 44 μm (325 mesh) to 20 μm (635 mesh), and the second mesh size is 210 μm

[0075] (70 mesh) to 53μm (270 mesh).

[0076] Scheme 10. The method according to any one of schemes 2 to 9, wherein the first powder

[0077] The first powder is present in an amount of about 15% to about 95% by volume of the powder mixture, and the second powder is present in an amount of about 5% to about 85% by volume of the powder mixture.

Claims

1. A sputtering target assembly, comprising: front surface; a rear surface, the rear surface being opposite to the front surface; a sputtering surface located on at least a portion of the front surface, the sputtering surface being formed of a metal or a metal alloy; a flange extending radially from the sputtering surface; as well as A sputtering well is formed on at least a portion of the front surface of the flange, the sputtering well being configured to capture and retain particles sputtered from the sputtering surface during a sputtering process in a non-planarized redeposited film, the sputtering well having an average surface roughness (Ra) of at least 25 μm and being formed by a plurality of particles adhered to the surface of the sputtering well, the plurality of adhered particles having a particle size distribution curve with at least two different normal distributions.

2. A method for forming a sputtering well on a sputtering target assembly, the method comprising: combining a first powder having a first mesh size and a second powder having a second mesh size to form a powder mixture comprising a plurality of particles, wherein the first mesh size and the second mesh size are different; and forming a sputtering well on a sputtering target assembly by applying the plurality of particles onto a textured surface of the sputtering target assembly by a cold spraying technique or a thermal spraying technique, wherein a particle size distribution curve of the formed sputtering well has at least two different normal distributions; wherein the sputtering well has an average surface roughness (Ra) of at least 25 μm; wherein the sputtering target assembly comprises a sputtering target formed of a metal or a metal alloy; The sputtering trap is configured to capture and hold particles sputtered from a sputtering target during a sputtering process in a non-planarized redeposited film.

3. The sputtering target assembly of claim 1 or the method of claim 2, wherein the plurality of particles are titanium particles or titanium alloy particles.

4. The sputtering target assembly of claim 1 or the method of claim 2, wherein the sputtering well has a surface roughness (Ra) of at least 38 μm.

5. The sputtering target assembly of claim 1 or the method of claim 2, wherein the particle size distribution profile has at least three different distributions.

6. The sputtering target assembly of claim 1 or the method of claim 2, further comprising the sputtering target mounted on a backing plate, wherein the backing plate includes the flange.

7. The sputtering target assembly of claim 1 or the method of claim 2, wherein the sputtering target assembly is a monolithic sputtering target assembly.

8. The method of any one of claims 2 to 7, further comprising forming a textured surface on at least a portion of the sputtering target assembly by sandblasting, knurling, or machining, and wherein the particles adhere to at least a portion of the textured surface.

9. The method according to any one of claims 2 to 8, wherein the first mesh size is 44 μm (325 mesh) to 20 μm (635 mesh), and the second mesh size is 210 μm (70 mesh) to 53 μm (270 mesh).

10. The method of any one of claims 2 to 9, wherein the first powder is present in an amount of about 15% to about 95% by volume of the powder mixture, and the second powder is present in an amount of about 5% to about 85% by volume of the powder mixture.

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