Modular sputtering target with precious metal insert and skirt - Patents.com

Abstract

A sputtering target comprising a target insert including a target metal compound and a skirt structure including a primary skirt and a secondary skirt, the primary skirt being disposed adjacent at least a portion of the secondary skirt and including a first metal compound, the secondary skirt including a second metal compound different from the first metal compound.

Description

[Technical field]

[0001]

[0001] Claim of priority This application claims priority to U.S. Provisional Patent Application No. 63 / 214,411, filed June 24, 2021, which is incorporated herein by reference.

[0002]

[0002] This disclosure relates to sputtering targets for deposition of precious metals, and more particularly, to sputtering targets having a target insert and a skirt structure. [Background technology]

[0003]

[0003] Sputtering deposition is a physical vapor deposition (PVD) method of thin film deposition. The sputtering process very roughly involves ejecting material from a sputtering target (the source of material) onto a substrate. The availability of many process and material parameters makes it a complex process. Beneficially, it also offers great control over the growth and microstructure of the films thus formed.

[0004]

[0004] One type of sputtering is ion beam impact sputtering, in which a high energy source of ions is directed at a target source (target insert). The impact force of the ions imparts sufficient energy to the atoms of the target source to cause energetic atoms to be ejected (sputtered) from the target source, forming a particle flux and depositing a thin film on a substrate. Advantages of using ion beam sputter deposition include isolation of the substrate from energetic electron bombardment and independent control over the ion energy and current density impinging on the target. The basic technology of ion beam sputter deposition is well known.

[0005]

[0005] In general, any target source material that can be physically placed in a vacuum chamber can be sputtered by ion beam deposition. This includes materials composed of single chemical elements, alloys, composites, and compounds. When the target source is relied upon as the primary source of deposition material in depositing a thin film of a given chemical composition, the target source can be prepared by vacuum, inert, or open atmosphere melting. The material is melted by induction, resistance, electric arc, or similar melting methods. The material is then formed into the appropriate shape by known material processing methods. Alternatively, the material can be formed by several powder consolidation methods, such as pressing and sintering, hot isostatic pressing, uniaxial hot pressing, or similar well-known techniques. These methods can be designed to produce materials of high purity and structural integrity. The deposition target is typically attached to a backing holder or plate by a bonding layer for precise placement in the vacuum chamber. The bonding layer usually comprises solder.

[0006]

[0006] When the ion beam reaches the target insert and begins sputtering, in some cases due to process inconsistencies, the beam may contact areas other than the target itself. Often, an outer skirt is utilized to hold the target insert in place. As an example, U.S. Pat. No. 6,755,944 discloses an ion beam deposition target source consisting of a removable centrally located inner insert surrounded by an outer region. The insert can be removed and replaced when worn, while the outer region of the target source, which is not worn by the ion beam, remains attached in place to the backing plate. The inner insert and the outer region are connected to each other by a connection that includes an engaging lip or groove structure located on the opposing mating surfaces of the inner insert and the outer region, thereby forming a deposition target source when these components are integrated together. The deposition target source can be attached to a backing plate that is installed in an ion beam deposition machine by a bonding layer.

[0007] The outer skirt can detrimentally come into contact with the ion beam, with the result that the skirt itself becomes a target material that can undesirably release contaminating particles that have a detrimental effect on the desired film composition and properties.

[0008]

[0008] To remedy this problem, the skirt material can be constructed of the same high purity (and high cost) precious metal / alloy as the target insert. Unfortunately, the utilization of significantly greater amounts of precious metal in a sputtering target increases costs, especially at a time when precious metal prices are historically high. Summary of the Invention [Problem to be solved by the invention]

[0009]

[0009] Therefore, in view of the known technology, there is a need for a sputtering target having an outer skirt that effectively secures the target insert while minimizing or eliminating film contamination, reducing precious metal content and overall cost. [Means for solving the problem]

[0010]

[0010] In one embodiment, the present disclosure relates to a sputtering target comprising a target insert and a skirt structure. The target insert comprises a target metal compound, preferably comprising rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, tungsten, or silver, or a combination or alloy thereof. The skirt structure comprises a primary skirt and a secondary skirt, the primary skirt being disposed adjacent to at least a portion of the secondary skirt. The primary skirt comprises a first metal compound, such as rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, or silver, or a combination thereof. The secondary skirt comprises a second metal compound, such as copper, nickel, aluminum, or a combination or alloy thereof. In one embodiment, the second metal compound is different from the first metal compound. The first metal compound optionally comprises the same metal as the target insert. The primary skirt may have a thickness in the range of 10 microns to 6350 microns, and the secondary skirt may have a thickness in the range of 100 microns to 25000 microns, preferably 100 microns to 6350 microns, and / or the ratio of the thickness of the primary skirt to the thickness of the secondary skirt may be less than 5:1. The CTE of the first metal compound may be in the range of 5.5 to 11.5, and the CTE of the second metal compound may be in the range of 11.5 to 21.5, and / or the variance between the CTE of the first metal compound and the CTE of the second metal compound may be less than 200%. The conductivity of the first metal compound may be in the range of 100 to 200, and the conductivity of the second metal compound may be in the range of 315 to 515, and / or the variance between the conductivity of the first metal compound and the conductivity of the second metal compound may be less than 200%. The primary skirt may be bonded to the secondary skirt, for example, by soldering or diffusion bonding. In some cases, the bonding is not achieved by coating or plating. The target may further include a backing plate disposed beneath the target insert and beneath the skirt, and / or a bonding layer disposed between the primary and secondary skirts.In use with a substrate, the target may exhibit a deposition rate that varies by less than 25% across the substrate and / or a film uniformity that varies by less than 25% across the substrate.

[0011] In one embodiment, the present disclosure relates to a sputtering target comprising a target insert including a target metal compound and a skirt structure including a primary skirt and a secondary skirt, the primary skirt being bonded to the secondary skirt, the primary skirt including a first metal compound and the secondary skirt including a second metal compound different from the first metal. The primary skirt may be bonded to the secondary skirt, for example, by soldering or diffusion bonding. In some cases, the bonding is not achieved by coating or plating. The target insert includes a target metal compound, preferably the target metal compound includes rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, tungsten, or silver, or a combination or alloy thereof. The skirt structure includes a primary skirt and a secondary skirt, the primary skirt being disposed adjacent to at least a portion of the secondary skirt. The primary skirt includes a first metal compound, for example, rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, or silver, or a combination thereof. The secondary skirt comprises a second metal compound, for example, copper, nickel, aluminum, or a combination or alloy thereof. In an embodiment, the second metal compound is different from the first metal compound. The first metal compound optionally comprises the same metal as the target insert. The primary skirt may have a thickness in the range of 10 microns to 6350 microns, and the secondary skirt may have a thickness in the range of 100 microns to 25000 microns, preferably 100 microns to 6350 microns, and / or the ratio of the thickness of the primary skirt to the thickness of the secondary skirt may be less than 5:1. The CTE of the first metal compound may be in the range of 5.5 to 11.5, and the CTE of the second metal compound may be in the range of 11.5 to 21.5, and / or the variance between the CTE of the first metal compound and the CTE of the second metal compound may be less than 200%.The conductivity of the first metal compound may be in the range of 100-200, the conductivity of the second metal compound may be in the range of 315-515, and / or the variance between the conductivity of the first metal compound and the conductivity of the second metal compound may be less than 200%. The target may further comprise a backing plate disposed under the target insert and under the skirt, and / or a bonding layer disposed between the primary skirt and the secondary skirt. In use with a substrate, the target may exhibit a deposition rate that varies by less than 25% across the substrate and / or a film uniformity that varies by less than 25% across the substrate.

[0012] In one embodiment, the present disclosure relates to a sputtering target comprising a target insert including a target metal compound and a skirt structure including a primary skirt and a secondary skirt, the ratio of the thickness of the primary skirt to the thickness of the secondary skirt being less than 5:1, the primary skirt including a first metal compound and the secondary skirt including a second metal compound different from the first metal. The target insert includes a target metal compound, preferably the target metal compound includes rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, tungsten, or silver, or a combination or alloy thereof. The skirt structure includes a primary skirt and a secondary skirt, the primary skirt being disposed adjacent to at least a portion of the secondary skirt. The primary skirt includes a first metal compound, such as rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, or silver, or a combination or alloy thereof. The secondary skirt includes a second metal compound, such as copper, nickel, aluminum, or a combination or alloy thereof. In one embodiment, the second metal compound is different from the first metal compound. The first metal compound optionally comprises the same metal as the target insert. The primary skirt may have a thickness in the range of 10 microns to 6350 microns and the secondary skirt may have a thickness in the range of 100 microns to 25000 microns, preferably 100 microns to 6350 microns. The CTE of the first metal compound may be in the range of 5.5 to 11.5, the CTE of the second metal compound may be in the range of 11.5 to 21.5, and / or the variance between the CTE of the first metal compound and the CTE of the second metal compound may be less than 200%. The conductivity of the first metal compound may be in the range of 100 to 200, the conductivity of the second metal compound may be in the range of 315 to 515, and / or the variance between the conductivity of the first metal compound and the conductivity of the second metal compound may be less than 200%. The primary skirt may be bonded to the secondary skirt, for example by soldering or diffusion bonding. In some cases, bonding is not achieved by coating or plating.The target may further comprise a backing plate disposed beneath the target insert and beneath the skirt, and / or a bonding layer disposed between the primary and secondary skirts. In use with a substrate, the target may exhibit a deposition rate that varies by less than 25% across the substrate and / or a film uniformity that varies by less than 25% across the substrate. [Brief description of the drawings]

[0013] [Figure 1]

[0013] FIG. 1 is a cross-sectional view of a sputtering target according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014]

[0014] Introduction As mentioned above, conventional sputtering targets may include a target insert and a skirt to hold the insert in place. Typically, the skirt material is constructed of the same high purity (and high cost) precious metal / alloy as the target insert, which results in a sputtering target that is not cost-effective, at least in part due to the high cost of typical target precious metals, such as rhodium, gold, or platinum. In the past, the cost of precious metals was not so high, and the art was not valued for addressing the composition of the skirt material, especially in light of the complexities and process steps involved with such two-part or two-layer structures. In other words, a two-layer skirt configuration has not been discussed or addressed in the literature before.

[0015]

[0015] The inventors have now discovered that the utilization of a skirt comprising two components, a primary skirt comprising a first target precious metal compound, and a secondary skirt comprising a second (less costly) metal compound, simultaneously and advantageously reduces the overall precious metal content of the sputtering target while effectively reducing or eliminating film contamination. When configured as described herein, the primary skirt has been discovered to sputter high purity deposition particles with minimal impurities upon contact with the ion beam. In some cases, the ion beam does not reach (or only marginally contacts) the secondary skirt. When the primary and secondary skirts are configured in this manner (and particularly with the thicknesses and thickness ratios described herein), few, if any, undesirable deposition particles are expelled from the overall skirt structure. Thus, the synergistic combination of the primary and secondary skirts achieves the beneficial goal of effectively securing the target insert while minimizing or eliminating film contamination and reducing precious metal content and overall cost.

[0016] In contrast, conventional skirt configurations are constructed entirely of expensive precious metals or entirely of lower cost metals, which result in film contamination when contacted by the ion beam. These conventional skirt configurations have presented the process / cost problems discussed herein.

[0017]

[0017] Sputtering target In one embodiment, the present disclosure relates to a sputtering target comprising a target insert containing a target metal and a skirt structure for holding the target insert in place.

[0018]

[0018] The skirt structure advantageously includes both a primary skirt and a secondary skirt (as opposed to a conventional skirt configuration). The primary skirt is disposed adjacent to at least a portion of the secondary skirt, e.g., the primary skirt may be disposed in a layered manner over the secondary skirt. The primary skirt includes a first metal compound and the secondary skirt includes a second metal compound. Importantly, the first metal compound may be different from the second metal compound, e.g., the first metal compound includes a noble target metal while the second metal compound includes a less expensive "filler" metal. The use of such first and second metal compounds provides the benefits discussed above.

[0019] In some cases, the primary skirt and the secondary skirt (and optional other skirt components in the skirt structure) are configured as layers. For example, the primary may be a layer positioned over at least a portion of the secondary skirt, and the secondary skirt may also be a layer positioned over, for example, a backing plate. In some cases, the primary skirt is positioned so as to be substantially flush with the target insert, for example, flush with the target insert.

[0020]

[0020] As mentioned above, the inserts can be advantageously removed and replaced when worn out. The skirt structure that is not worn out by the ion beam can be kept in place (attached to the backing plate) or can be reused with a new central insert when the target source is removed for more efficient recycling. The advantages of the skirt configurations mentioned above can also be applied to the use of replacement target inserts. For example, when the target insert is replaced, the same skirt structure may be used, thus allowing the replacement target insert to be fixed while minimizing or eliminating film contamination and reducing precious metal content and overall cost.

[0021]

[0021] Sputtering target sources can be made in a variety of shapes and sizes and can include a variety of materials, including, but not limited to, metals and metal alloys, composites, ceramic compounds, and other chemical compositions (see discussion below). In some cases, the sputtering target is a circular shape having a diameter of about 25 cm to about 40 cm, an oval shape having dimensions of about 22 cm x 30 cm, and a rectangular shape having dimensions of about 25 cm x 36 cm. These dimensions are merely exemplary and are not intended to limit the scope of the present disclosure.

[0022] Target insert and skirt structure Target inserts are generally quite well known. Also, the configuration of the target insert may vary widely. In some cases, the insert is centrally located. A skirt structure may be disposed (at least partially) adjacent to the target insert and may hold the insert in place. In some cases, the skirt may (completely) surround the insert and hold it in place. For example, the insert and skirt may be configured or coupled in close proximity to one another. In some embodiments, a mating connection may be used to establish a connection between the insert and the skirt structure to prevent contamination, e.g., non-precious metal atoms, from forming in the particle flux.

[0023]

[0023] The target insert includes (is made of) a target metal compound. The target metal provides the material that is sputtered to form a film on the substrate. Target metal compounds are well known and can vary widely, and are generally high-cost metals or alloys. The target metal compound may be one or more precious metals. Exemplary target metals / alloys include, but are not limited to, rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, tungsten, or silver, or combinations or alloys thereof. The target metal may also include combinations and alloys of the above-mentioned metals. In some cases, the target metal is rhodium. Broadly speaking, the target metal compound may be any material or compound that can be effectively sputtered onto a substrate.

[0024]

[0024] As mentioned above, the skirt structure comprises a primary skirt and a secondary skirt. In some cases, the primary skirt and the secondary skirt are bonded together. In one example, the bonding can be achieved by soldering or diffusion bonding. In some embodiments, the bonding is not achieved by a coating process or plating. The inventors have found that in some cases, coating and plating should be avoided due to problems resulting from the additional extra processing steps required. Also, it has been found that supply chain issues are significant with coating and plating. In contrast, the use of other methods, such as the methods described above, provides improved interlayer adhesion along with bonding efficiency, e.g., consistency of coefficient of thermal expansion (CTE) across the skirt structure, and processing efficiency, which is particularly important under sputtering operating conditions, e.g., higher temperatures. Processing efficiency includes, for example, elimination of process steps, process conditions, and logistics issues. By using methods such as soldering or diffusion bonding, fewer processing steps and / or logistics are required.

[0025]

[0025] The primary skirt is a part that may (inadvertently) come into contact with the ion beam. For at least this reason, the primary skirt may be constructed of a high purity metal / alloy similar, if not the same, as the target metal / alloy. The primary skirt includes a first metal compound, which may include the metals mentioned above with respect to the target metal. In some cases, the first metal compound includes the same metal as the target metal compound. In some embodiments, the first metal compound and / or the target metal compound are high purity metals, e.g., pure metals with little or no contamination, e.g., less than 10 wt% other metals, e.g., less than 5 wt%, less than 3 wt%, less than 1 wt%, less than 0.5 wt%, or less than 0.1 wt% other metals.

[0026]

[0026] In some embodiments, both the first metal compound and the target metal compound are alloys, and some of the alloying metals are present in both the first metal compound and the target metal compound, for example, there may be some overlap of metals in the first metal compound and the target metal compound.

[0027]

[0027] The secondary skirt serves the purpose of interlocking with the primary skirt to secure the target insert to the sputtering target. It has been discovered that when a primary skirt is used, the metallurgy (composition of the second metal compound) of the secondary skirt may advantageously be of a lower cost metal. One tenet of the present invention is the ability to effectively replace a portion of the skirt, which is typically made of a more expensive material, with at least some portion of the less expensive material (the secondary skirt).

[0028]

[0028] The second metal compound is a commonly known, lower cost metal or alloy. Exemplary second metals / alloys include, but are not limited to, copper, nickel, aluminum, or (optionally) cobalt, or combinations or alloys thereof. In some cases, cobalt may be included in the second metal compound and the first metal compound, but in significantly different, e.g., higher, amounts. The second metal compound may also include combinations and alloys of the above metals. In some cases, the second metal is copper. In some cases, the second metal compound (or the first metal compound in some cases) may not be metallic in nature. The second metal (or the first metal compound in some cases) may include materials including single chemical elements, alloys, composites, polymers, oxides, ceramics, fillers, and other compounds. Generally, these materials or compounds are high cost. Other known filler materials are contemplated.

[0029]

[0029] In some cases, one or more of these components in the recitation in this section may be explicitly excluded, for example, by claim language. This is contemplated herein. For example, the disclosed compositions may exclude cobalt as a first metal compound, or may exclude aluminum as a second metal compound. This option of exclusion is not limited to a particular example, but rather may apply to all other components or steps in the recitation herein. This supports the explicit exclusion of one or more of these components in the claim language.

[0030]

[0030] The inventors have further found that the thickness of the components of the skirt structure is important. In particular, the thickness of the primary skirt must be sufficient for the ion beam to contact without reaching the secondary skirt and thus sputtering undesired contaminant particles. In some embodiments, the primary skirt has a thickness of more than 10 microns, such as more than 20 microns, more than 50 microns, more than 100 microns, more than 300 microns, more than 500 microns, more than 800 microns, more than 1000 microns, more than 2000 microns, more than 3000 microns, more than 4000 microns, more than 5000 microns, or more than 6000 microns. In terms of ranges, the primary skirt may have a thickness in the range of 10 microns to 15000 microns, such as 100 microns to 10000 microns, 10 microns to 7000 microns, 10 microns to 6350 microns, 50 microns to 5000 microns, 100 microns to 4000 microns, 500 microns to 3500 microns, 500 microns to 3000 microns, or 1000 microns to 2500 microns. In terms of upper limits, the primary skirt may have a thickness less than 15000 microns, such as less than 12000 microns, less than 10000 microns, less than 7000 microns, less than 6000 microns, less than 5000 microns, less than 4000 microns, less than 3500 microns, less than 3000 microns, less than 2500 microns, less than 2000 microns, or less than 1500 microns.

[0031] In some cases, the secondary skirt has a thickness of more than 100 microns, such as more than 500 microns, more than 800 microns, more than 1000 microns, more than 2000 microns, more than 3000 microns, more than 4000 microns, more than 5000 microns, or more than 6000 microns. In terms of range, the secondary skirt may have a thickness in the range of 100 microns to 25000 microns, such as 100 microns to 6350 microns, 500 microns to 20000 microns, 500 microns to 15000 microns, 500 microns to 10000 microns, 500 microns to 7000 microns, 1000 microns to 6000 microns, 2000 microns to 6000 microns, or 3000 microns to 5000 microns. In terms of upper limits, the secondary skirt may have a thickness of less than 25000 microns, such as less than 20000 microns, less than 15000 microns, less than 10000 microns, less than 7000 microns, such as less than 6000 microns, less than 5000 microns, less than 4000 microns, less than 3500 microns, less than 3000 microns, less than 2500 microns, less than 2000 microns, or less than 1500 microns.

[0032]

[0032] As used herein, the limits "greater than" and "less than" may also include their associated numerical values. In other words, "greater than" and "less than" may be interpreted as "greater than or equal to" and "less than or equal to." It is contemplated that this language may be later amended in the claims to include "or equal to." For example, "greater than 4.0" may be interpreted as "greater than or equal to 4.0" and may also be later amended in the claims.

[0033] Importantly, in some cases, the ratio of the thickness of the primary skirt to the thickness of the secondary skirt is less than 5:1, such as less than 2:1, less than 1:1, less than 0.7:1, less than 0.5:1, less than 0.3:1, less than 0.2:1, or less than 0.1:1. In some cases, the primary skirt is thinner than the secondary skirt. In some embodiments, the primary skirt must still be robust enough to prevent the ion beam from reaching the secondary skirt. For example, the ratio of the thickness of the primary skirt to the thickness of the secondary skirt may be greater than 0.1:1, such as greater than 0.2:1, greater than 0.3:1, greater than 0.4:1, greater than 0.5:1, greater than 0.6:1, greater than 0.7:1, greater than 0.8:1, greater than 0.9:1, or greater than 1:1.

[0034]

[0034] The first metal compound and the second metal compound must also interact well enough with each other: the properties of the metal compounds should in some cases not differ too much.

[0035]

[0035] CTE (0 to 100°C (x10 -6 ℃ -1 )) may be in the range of 4 to 20, e.g., 5 to 19, 7 to 15, 5 to 11, 5.5 to 10.5, 6 to 10, 6.5 to 9.5, 7 to 9, or 7.5 to 8.5. In terms of upper limits, the CTE of the first metal may be less than 20, e.g., less than 19, less than 15, less than 12, less than 10.5, less than 10, less than 9.5, less than 9, or less than 8.5. In terms of lower limits, the CTE of the first metal may be greater than 4, e.g., greater than 5, greater than 5.5, greater than 6, greater than 6.5, greater than 7, greater than 7.5, greater than 8, or greater than 8.5.

[0036]

[0036] CTE (0 to 100°C (x10 -6 ℃ -1)) may be in the range of 4 to 20, e.g., 4 to 18, 5 to 15, 11.5 to 21.5, e.g., 13.5 to 19.5, 14.5 to 18.5, 15.5 to 17.5, or 16 to 17. In terms of upper limits, the CTE of the second metal may be less than 21.5, e.g., less than 20, less than 19.5, less than 18.5, less than 17.5, or less than 17. In terms of lower limits, the CTE of the second metal may be greater than 4, e.g., greater than 6, greater than 8, greater than 10, or 11.5, e.g., greater than 13.5, greater than 14.5, greater than 15.5, or greater than 16.

[0037]

[0037] Conductivity of the first metal compound (0-100°C (Wm -1 K -1 )) may be in the range of 50 to 350, for example 50 to 300, 100 to 300, 100 to 250, 120 to 180, 130 to 170, 140 to 160, or 145 to 155. In terms of the upper limit, the conductivity of the first metal compound may be less than 350, for example less than 300, less than 250, less than 200, less than 180, less than 170, less than 160, or less than 155. In terms of the lower limit, the conductivity of the first metal compound may be greater than 50, for example greater than 100, greater than 120, greater than 130, greater than 140, or greater than 145.

[0038]

[0038] Conductivity of the second metal compound (0-100°C (Wm -1 K -1 )) may be in the range of 200 to 515, for example 200 to 450, 250 to 400, 315 to 515, 365 to 465, 390 to 440, 400 to 430, or 410 to 420. In terms of the upper limit, the conductivity of the second metal compound may be less than 515, for example less than 465, less than 440, less than 430, or less than 420. In terms of the lower limit, the conductivity of the second metal compound may be greater than 200, for example greater than 250, greater than 300, greater than 315, greater than 365, greater than 390, greater than 400, or greater than 410.

[0039]

[0039] In some embodiments, the variance between the CTE of the first metal compound and the CTE of the second metal compound is less than 200%, for example less than 150%, less than 100%, less than 75%, less than 50%, less than 25%, or less than 10%.

[0040]

[0040] In some embodiments, the variance between the conductivity of the first metal compound and the conductivity of the second metal compound is less than 200%, for example less than 150%, less than 100%, less than 75%, less than 50%, less than 25%, or less than 10%.

[0041]

[0041] By controlling these properties, improved bonding between the primary skirt and the secondary skirt is surprisingly achieved. For example, uniform bonding and uniform target is achieved, e.g., high adhesion and hot spots are minimized or eliminated. As a result, when used with a substrate in a sputtering operation, the sputtering target exhibits a deposition rate (Angstroms / second) that varies by less than 25% across the substrate, e.g., less than 20%, less than 15%, less than 10%, less than 5%, or less than 1%. As another benefit, when used with a substrate in a sputtering operation, the sputtering target exhibits a film uniformity that varies by less than 25% across the substrate, e.g., less than 20%, less than 15%, less than 10%, less than 5%, or less than 1%.

[0042] Bonding Layer and Other Layers In addition to the above-mentioned components, the sputtering target may further comprise other layers. For example, the sputtering target may further comprise a bonding layer disposed between the primary skirt and the secondary skirt. The bonding layer may be the result of a bonding operation, such as a soldering, diffusion bonding, or plating operation. Multiple bonding layers are contemplated. The composition and treatment of the bonding layer may vary widely. Several bonding layer formation techniques are known. The bonding layer, in some cases, comprises solder.

[0043] In some cases, a backing plate is provided that is disposed beneath the target insert and beneath the skirt. The backing plate may vary widely, and many conventional backing plates are known in the art. In some cases, the target and / or skirt structure may be attached by a bonding layer to a backing plate that is located in the ion beam deposition (IBD) machine.

[0044] The figure illustrates an exemplary sputtering target 100 comprising a target insert 102 and a skirt structure 104. In this particular case, the skirt structure 104 surrounds and receives the target insert 102. As shown in the figure, the skirt structure comprises a primary skirt 106 and a secondary skirt 108, which are constructed and arranged as described herein. The target insert 102 and the skirt structure 104 are disposed on a backing plate 110.

[0045]

[0045] In some cases, once the target becomes sufficiently worn that replacement is necessary, the backing plate can be heated to a temperature sufficient to melt the solder, thereby removing the worn insert, demonstrating the modularity of the disclosed sputtering targets.

[0046]

[0046] Embodiment The following embodiments are contemplated: All combinations of features and embodiments are contemplated.

[0047]

[0047] Embodiment 1: A sputtering target comprising: a target insert including a target metal compound; and a skirt structure including a primary skirt and a secondary skirt, the primary skirt being positioned adjacent to at least a portion of the secondary skirt, wherein the primary skirt includes a first metal compound and the secondary skirt includes a second metal compound different from the first metal compound.

[0048]

[0048] Embodiment 2: An embodiment of embodiment 1, wherein the first metal compound comprises the same metal as the target insert.

[0049]

[0049] Embodiment 3: The embodiment of embodiment 1 or 2, wherein the first metal compound comprises rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, or silver, or a combination thereof.

[0050]

[0050] Embodiment 4: The embodiment of embodiments 1 to 3, wherein the second metal compound comprises copper, nickel, aluminum, or a combination or alloy thereof.

[0051]

[0051] Embodiment 5: The embodiment of embodiments 1 through 4, wherein the target metal comprises rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, tungsten, or silver, or a combination or alloy thereof.

[0052]

[0052] Embodiment 6: An embodiment of any one of embodiments 1 to 5, wherein the primary skirt has a thickness in the range of 10 microns to 6350 microns.

[0053]

[0053] Embodiment 7: An embodiment of any one of embodiments 1 to 6, wherein the secondary skirt has a thickness in the range of 100 microns to 25000 microns, preferably 100 microns to 6350 microns.

[0054]

[0054] Embodiment 8: An embodiment of any one of embodiments 1 to 7, wherein the ratio of the primary skirt thickness to the secondary skirt thickness is less than 5:1.

[0055]

[0055] Embodiment 9: An embodiment of any one of embodiments 1 to 8, wherein the CTE of the first metal compound is in the range of 5.5 to 11.5, the CTE of the second metal compound is in the range of 11.5 to 21.5, and the variance between the CTE of the first metal compound and the CTE of the second metal compound is less than 200%.

[0056]

[0056] Embodiment 10: An embodiment of embodiments 1 to 9, wherein the conductivity of the first metal compound is in the range of 100 to 200, the conductivity of the second metal compound is in the range of 315 to 515, and the variance between the conductivity of the first metal compound and the conductivity of the second metal compound is less than 200%.

[0057]

[0057] Embodiment 11: The embodiment of embodiments 1 to 10, wherein the primary skirt is joined to the secondary skirt.

[0058]

[0058] Embodiment 12: An embodiment of any one of embodiments 1 to 11, wherein the bonding is achieved by soldering or diffusion bonding.

[0059]

[0059] Embodiment 13: The embodiment of embodiments 1 to 12, wherein the bonding is not achieved by coating or plating.

[0060]

[0060] Embodiment 14: The embodiment of embodiments 1 to 13, further comprising a backing plate disposed beneath the target insert and beneath the skirt.

[0061]

[0061] Embodiment 15: The embodiment of any one of embodiments 1 to 14, further comprising a bonding layer disposed between the primary skirt and the secondary skirt.

[0062]

[0062] Embodiment 16: Any of embodiments 1 to 15, wherein in use with a substrate, the target exhibits a deposition rate that varies by less than 25% across the substrate.

[0063]

[0063] Embodiment 17: Any of embodiments 1 to 16, wherein in use with a substrate, the target exhibits a film uniformity that varies by less than 25% across the substrate.

[0064]

[0064] Embodiment 18: A sputtering target comprising a target insert containing a target metal compound and a skirt structure including a primary skirt and a secondary skirt, the primary skirt being joined to the secondary skirt, wherein the primary skirt contains a first metal compound and the secondary skirt contains a second metal compound different from the first metal.

[0065]

[0065] Embodiment 19: The embodiment of embodiment 18, wherein the bonding is achieved by soldering or diffusion bonding, and preferably not by coating or plating.

[0066]

[0066] Embodiment 20: A sputtering target having a skirt structure including a target insert containing a target metal compound; a primary skirt and a secondary skirt, wherein the ratio of the thickness of the primary skirt to the thickness of the secondary skirt is less than 5:1, and the primary skirt contains a first metal compound and the secondary skirt contains a second metal compound different from the first metal.

[0067]

[0067] Embodiment 21: The embodiment of embodiment 20, wherein the first metal compound comprises the same metal as the target insert.

[0068]

[0068] Embodiment 22: The embodiment of embodiment 20 or 21, wherein the first metal compound comprises rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, or silver, or a combination thereof.

[0069]

[0069] Embodiment 23: The embodiment of any one of embodiments 20 to 22, wherein the second metal compound comprises copper, nickel, aluminum, or a combination or alloy thereof.

[0070]

[0070] Embodiment 24: The embodiment of any of embodiments 20 to 23, wherein the target metal comprises rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, tungsten, or silver, or a combination or alloy thereof.

[0071]

[0071] Embodiment 25: The embodiment of any one of embodiments 20 to 24, wherein the primary skirt has a thickness in the range of 10 microns to 6350 microns.

[0072]

[0072] Embodiment 26: An embodiment of any of embodiments 20 to 25, wherein the secondary skirt has a thickness in the range of 100 microns to 25000 microns, 100 microns to 6350 microns.

[0073]

[0073] Although the present invention has been described in detail, modifications within the spirit and scope of the present invention will be readily apparent to those skilled in the art. In view of the above discussion, the relevant knowledge in the art, and the references discussed above in conjunction with the background art and detailed description, the disclosures of which are all incorporated herein by reference. Furthermore, it should be understood that some of the aspects of the present invention recited below and / or in the appended claims, as well as the various embodiments and various features, may be combined or exchanged in whole or in part. In the above description of various embodiments, those embodiments that refer to other embodiments may be appropriately combined with other embodiments as understood by those skilled in the art. Furthermore, those skilled in the art will understand that the above description is for illustrative purposes only and is not intended to be limiting.

Claims

1. A sputtering target, comprising: a target insert containing a target metal compound; and a skirt structure including a primary skirt and a secondary skirt, wherein the primary skirt is disposed adjacent to at least a part of the secondary skirt. The sputtering target further comprises: wherein the primary skirt contains a first metal compound, and the secondary skirt contains a second metal compound different from the first metal.

2. The target according to claim 1, wherein the first metal compound contains the same metal as the target insert.

3. The target according to claim 1, wherein the first metal compound contains rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, or silver, or a combination thereof.

4. The target according to claim 1, wherein the second metal compound contains copper, nickel, aluminum, or a combination or alloy thereof.

5. The target according to claim 1, wherein the target metal contains rhodium, ruthenium, platinum, gold, iridium, cobalt, tantalum, tungsten, or silver, or a combination or alloy thereof.

6. The target according to claim 1, wherein the primary skirt has a thickness in the range of 10 microns to 6350 microns.

7. The target according to claim 1, wherein the secondary skirt has a thickness in the range of 100 microns to 6350 microns.

8. The target according to claim 1, wherein the ratio of the thickness of the primary skirt to the thickness of the secondary skirt is less than 5:

1.

9. The target according to claim 1, wherein the CTE of the first metal compound is in the range of 5.5 to 11.5, the CTE of the second metal compound is in the range of 11.5 to 21.5, and the dispersion between the CTE of the first metal compound and the CTE of the second metal compound is less than 200%.

10. The target according to claim 1, wherein the conductivity of the first metal compound is in the range of 100 to 200, the conductivity of the second metal compound is in the range of 315 to 515, and the dispersion between the conductivity of the first metal compound and the conductivity of the second metal compound is less than 200%.

11. The target according to claim 1, wherein the primary skirt is joined to the secondary skirt.

12. The target according to claim 11, wherein the joining is achieved by soldering or diffusion bonding, and preferably, the joining is not achieved by coating or plating.

13. The target according to claim 1, further comprising a backing plate disposed under the target insert and under the skirt.

14. The target according to claim 1, further comprising a joining layer disposed between the primary skirt and the secondary skirt.

15. The target according to claim 1, which, in use with a substrate, exhibits a deposition rate that varies by less than 25% across the substrate and / or exhibits a film uniformity that varies by less than 25% across the substrate.

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