CN1681960A - Copper sputtering targets and methods of forming copper sputtering targets - Google Patents

Abstract

The invention includes a copper-comprising sputtering target. The target is monolithic or bonded and contains at least 99.99% copper by weight and has an average grain size of from 1 micron to 50 microns. The copper-comprising target has a yield strength of greater than or equal to about 15 ksi and a Brinell hardness (HB) of greater than about 40. The invention includes copper alloy monolithic and bonded sputtering targets consisting essentially of less than or equal to about 99.99% copper by weight and a total amount of alloying element(s) of at least 100 ppm and less than 10% by weight. The targets have an average grain size of from less than 1 micron to 50 microns and have a grain size non-uniformity of less than about 15% standard deviation (1-sigma) throughout the target. The invention additionally includes methods of producing bonded and monolithic copper and copper alloy targets.

Description

Copper sputtering target and method of forming copper sputtering target

technical field

The present invention relates to copper-containing monolithic sputtering targets and copper-containing bonded sputtering targets. The invention also relates to methods of forming copper-containing monoliths and connecting sputter targets.

Background of the invention

Currently, high purity copper sputtering targets and copper alloy sputtering targets are used in many applications including, for example, integrated circuit fabrication. The quality of copper-containing structures such as interconnects and films depends on the sputtering performance of the target. Many factors of the sputtering target can affect the sputtering performance of the target, these factors include: the average particle size and uniformity of the particle size of the target; the crystallographic orientation/texture of the target; the uniformity of the structure and composition in the target and The strength of the target. Typically, a smaller average particle size correlates with high strength of the material. Additionally, the amount of alloying can affect the strength and hardness of the target, typically increased alloying results in increased target strength.

Due to the low strength of high purity copper (greater than 99.99% copper by weight), conventional high purity copper sputtering targets are typically made as connection targets. A bonded copper sputtering target has a high purity copper target bonded to a support plate comprising a relatively high strength material such as aluminum. However, the high temperatures used in the process of attaching the copper target to the support plate often lead to abnormal grain growth, which results in microstructural inhomogeneity and an increase in the overall average grain size. Typically, conventional high purity copper targets have an average particle size greater than 50 microns, which results in a relatively low yield strength. The resulting grain size and structural inhomogeneities in conventionally formed high-purity copper sputter targets can adversely affect the quality of sputter-deposited high-purity copper films and interconnects.

In addition to the large grain size and abnormal grain growth that can occur during the bonding process, problems such as burn-through and short target life often plague diffusion-bonded copper targets. In addition, the connection process is complicated and time-consuming.

One method of increasing the particle size uniformity and strength of copper materials for sputtering targets is to alloy the copper with one or more "alloying" elements. However, since the presence of alloying elements affects the resistivity of copper, it is desirable to limit the total amount of alloying elements within the target to no greater than 10% by weight. For certain applications such as copper thin films and interconnects, where a resistivity comparable to that of high purity copper is required, the amount of alloying should be limited to less than or equal to 3% by weight. Another disadvantage of alloying is potential defects such as the formation of second phase precipitates or segregation.

While it is possible in some cases to treat conventional materials to reduce or remove precipitates or segregation defects, typically such treatments involve high temperatures that result in extremely large particle sizes (greater than 150 microns). Alternatively, application of conventional rolling and/or forging methods may in some cases achieve partial reduction of second phase precipitates or segregation defects present in conventional materials. However, remaining defects can still affect the quality of sputtered films. Currently, conventional processes to form copper alloys with less than or equal to 3 wt. % alloying elements result in targets typically having an average grain size greater than 30 microns, often greater than 50 microns, with secondary phase precipitates therein.

It would be desirable to develop methods of manufacturing copper sputtering targets and copper alloy sputtering targets with enhanced sputtering properties.

Summary of the invention

In one aspect, the invention includes a copper-containing sputtering target. The target contains at least 99.99% by weight copper and has an average particle size of 1-50 microns. The copper-containing target has a yield strength of greater than or equal to about 15 ksi and a Brinell hardness (HB) of greater than about 40.

In one aspect, the present invention includes a copper alloy sputtering target consisting essentially of less than or equal to about 99.99% by weight copper and at least one alloying element selected from the group consisting of: Cd, Ca, Au, Ag , Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W, Cr, O, Sb, Ir, P, As, Co, Te, Fe, S , Ti, Zr, Sc, Si, Mo, Pt, Nb, Re and Hf. The total amount of target alloying elements is at least 100 ppm, but less than 10% by weight. The target also has an average particle size of 1-50 microns and a particle size uniformity with a 1-σ standard deviation of less than about 15% throughout the target.

In one aspect, the invention includes a method of forming a monolithic sputtering target. A copper slab consisting essentially of copper and one or more alloying elements totaling less than or equal to 10% by weight is heated to a temperature of at least about 900°F and maintained at that temperature for at least about 45 minutes. The copper billet is hot forged to a reduction of at least about 50% in height to form a forged block, and the block is cold rolled to a reduction of at least about 60% to form a slab. The slab is heated to induce recrystallization and form a fine grain distribution with an average particle size of less than about 100 microns. The slab is then formed into a monolithic target shape.

In one aspect, the invention includes a method of forming a copper-containing sputtering target from a copper billet having a copper purity of at least 99.99%. The billet is hot forged at a temperature above 300° C. to reduce the height by at least 40%, thereby forming a forged block. The ingot was water quenched and subjected to an extrusion process comprising passing the ingot at least 4 passes through equal channel angular extrusion (ECAE). Solution treatment may optionally be performed after forging, followed by water quenching and ECAE. An intermediate anneal is performed between at least some of the ECAE passes and the block is cold rolled to a reduction of less than 90% after the ECAE treatment is complete to form a slab. The slab can be heat treated and then formed into a sputtering target.

Brief description of the drawings

Preferred embodiments of the present invention are described below with reference to the following drawings.

Fig. 1 is a flowchart describing an overview of a processing method according to an aspect of the present invention.

Figure 2 illustrates a billet during an initial processing step according to the invention.

Figure 3 is a schematic cross-sectional view of material being processed by an equal channel angular extrusion device.

Figure 4 illustrates the yield and ultimate tensile strengths of various copper and copper alloys processed by ECA with respect to standard 6N copper with a particle size of 40 microns and with respect to various back-up plates.

Figure 5 is an imaged EBSD/SEM image of the particle size distribution and texture of a 99.9999% copper material (6N) after equal channel angular extrusion followed by annealing at 250°C for 5 hours according to an aspect of the present invention.

FIG. 6 illustrates the grain area distribution of the material imaged in FIG. 5 . The material has an average particle size of approximately 6 microns.

Figure 7 illustrates the resulting average particle size in relation to the annealing treatment when measured by EBSD and optical microscopy. Copper material containing copper alloyed with 0.53 wt% Mg that had been subjected to 6 passes of ECA through Channel D was annealed.

Figure 8 illustrates the EBSD/SEM image of the Cu-0.53 wt% MgECAE material in Figure 7 after annealing at 300°C for 2 hours.

Figure 9 is an EBSD/SEM image of the grain structure of the Cu-0.53wt%Mg material in Figure 7 after annealing at 450°C for 1.5 hours.

Figure 10 illustrates an image of the material of Figure 9 obtained using optical microscopy.

Figure 11 is a graph depicting sampling for particle size and texture measurements of a target according to one aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention includes monolithic high purity copper sputtering targets, joined high purity copper sputtering targets, monolithic copper alloy sputtering targets, joined copper alloy sputtering targets and methods of making these targets. For the purposes of this specification, high-purity copper refers to copper or a copper material having at least 99.99% copper by weight. The present invention includes high purity targets having at least 99.99% to 99.99995% copper by weight. Additionally, the term "monolithic" is used to refer to a target that is used for sputtering without being attached to a support plate.

Linked or monolithic high purity targets according to the present invention have an average particle size of less than 1 micron to less than or equal to about 100 microns, preferably less than 50 microns. In some cases, the methods of the invention can be used to produce monolithic or linked targets having an average particle size of 1 to about 30 microns. In certain instances, monolithic and bonded targets of high purity copper according to the invention preferably have an average particle size of 1 to about 20 microns, such as from about 5 to about 10 microns.

The high-purity targets of the present invention have a particle size uniformity along the sputtered surface of the target and/or throughout the target that is less than or equal to about 15% standard deviation (1-σ) (also referred to as less than 15% non-uniformity). In certain cases, uniformity can be manifested as a standard deviation (1-σ) of less than or equal to 10%.

The high-purity copper sputtering targets of the present invention have a yield strength that is at least about 10% higher than that of a target having an average particle size of 50 microns and having substantially the same elemental composition, and in some cases, a target having an average particle size of 30 microns and having substantially the same elemental composition. The target height of the composition is at least about 10%. For purposes of this specification, the phrase "substantially the same elemental composition" refers to materials that have no detectable differences in composition. Typically, the yield strength imparted to the target by the method described below is greater than or equal to about 15 ksi.

The high-purity copper sputtering targets of the present invention have an ultimate tensile strength that is at least about 15% greater than a target having an average particle size of 50 microns and having substantially the same elemental composition, and in some cases, the ultimate tensile strength is greater than an average particle size of A 30 micron target with substantially the same elemental composition is at least about 15% larger. Additionally, the high purity copper target is at least 15% harder than a target having an average particle size of 30 microns and having substantially the same elemental composition. In certain instances, the high purity targets of the present invention have a Brinell hardness of greater than about 40 HB, and in certain instances, greater than about 60 HB.

In particular aspects, the high purity copper sputtering targets of the present invention have a purity of 99.99% (4N) or greater. For purposes of this specification, all percentages and included amounts are by weight unless specifically stated otherwise. In some aspects, the high purity target may preferably comprise 99.999% (5N) copper, may preferably comprise 99.9999% (6N) copper or may preferably comprise 99.99995% (6N5) copper.

The bonded high-purity copper target of the present invention comprises a high-purity copper target diffusely bonded to a support plate. In particular instances, the bonded target has a diffusion bonded yield strength of greater than 10 ksi, preferably greater than or equal to about 15 ksi, and in particular instances, a diffusion bonded yield strength of greater than or equal to about 30 ksi. Alternatively, another joining method may be used to join the target to the support plate, including, for example, one or more of isostatic pressing, roll cladding, welding, explosive joining, and frictionless forging. Preferably, another joining method may join the high purity copper target to the support plate to produce a joint with a yield strength greater than or equal to about 10 ksi.

The support plate used in the connection target of the present invention is preferably an aluminum or CuCr support plate. Other support plate materials may also be used as appropriate, as will be appreciated by those of ordinary skill in the art.

The present invention includes copper alloy sputtering targets containing less than or equal to about 99.99% by weight copper. Preferably, the copper alloy sputtering targets of the present invention consist essentially of less than or equal to about 99.99% by weight copper and at least one alloying element selected from the group consisting of: Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W, Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc, Si, Pt, Nb, Re, Mo and Hf. In particular cases, the at least one alloying element is preferably selected from Ag, Al, In, Zn, B, Ga, Mg, Sn, Ge, Ti and Zr. The total amount of the at least one alloying element present in the target is preferably at least about 100 ppm by weight to less than about 10% by weight. In some cases, the at least one alloying element is preferably present in an amount of at least 1000 ppm by weight to less than about 3 weight percent, more preferably less than about 2 weight percent.

In particular aspects, copper alloy sputtering targets according to the present invention have an average particle size of less than 1 micron. Alternatively, the copper alloy sputtering target has an average particle size of 1 to about 100 microns, preferably less than 50 microns. In some aspects, the copper alloy target preferably has a particle size of 1-30 microns. In some cases, applying the methods of the present invention can result in targets having an average particle size of less than or equal to 20 microns, and in particular aspects, from about 5 to about 10 microns. Additionally, the copper alloy targets of the present invention have particle size uniformity throughout the target and/or along the sputtered surface of the target. In particular aspects, the average particle size across the target has a particle size heterogeneity of less than 15% (less than or equal to about 15% of the particle size relative to the standard deviation (1-σ), in certain instances , having a standard deviation (1-σ) of less than or equal to about 10% (less than or equal to 10% non-uniformity).

The copper alloy sputtering targets of the present invention have a Brinell hardness of at least about 40 HB. In some cases, the targets of the present invention have a hardness of greater than or equal to about 60 HB. In addition, the copper alloy target has hardness uniformity along the sputtering surface and/or throughout the target. For example, in certain instances, the hardness throughout the copper alloy target has a standard deviation (1-σ) of less than about 5% (in other words, the target has less than 5% non-uniformity). In certain instances, the hardness uniformity has a standard deviation (1-σ) of less than about 3.5%.

The copper alloy targets of the present invention may be monolithic or, in another embodiment, may be joined. The bonded copper alloy target of the present invention may be bonded to the support plate by diffusion bonding or by applying one or more of isostatic pressing, roll cladding, welding, explosive bonding, frictionless forging, and other suitable bonding methods . In the case of joining copper alloy targets, the joint has a joint yield strength of greater than about 10 ksi, preferably greater than about 15 ksi.

Copper materials treated according to the method of the present invention can produce copper targets with textures ranging from extremely weak (close to random) to extremely strong, depending on the process route used (discussed below). For purposes of this specification, the term "copper" (as used in the terms "copper target", "copper material", "copper billet", etc.) generally refers to high purity copper or copper alloys. Exemplary weakly textured copper targets of the present invention have a grain orientation distribution function (ODF) of less than or equal to about 15 times of disorder. In certain instances, the target has an extremely weak texture, characterized by an ODF of less than about 5 orders of disorder.

The copper target may include a predominant grain orientation, where the term "predominant" refers to the presence of more grain orientations in the target than any single other grain orientation. It is to be noted that the term "predominantly" does not necessarily mean that the majority of the particles are present in this orientation. In contrast, the term "predominantly" means that there is no more of another single orientation within the target. In particular aspects, targets having a major grain orientation other than (220) can be fabricated using the methods of the invention.

Another process according to the invention makes it possible to produce copper targets with less random texture. The present invention includes treatments that can induce strong texture in fabricated copper articles, where the term "strongly textured" refers to materials with an ODF greater than about 15 times random. In addition, the targets of the present invention can have extremely strong textures, characterized by an ODF in excess of 20 times random. In certain cases, the targets of the present invention preferably have a major grain orientation other than (220).

The size of the copper target produced by the method of the present invention is not limited to a specific value. Additionally, targets can be made in many shapes, such as circular or rectangular. Due to the increased strength of the material produced by the method relative to the material produced by the conventional method, it is possible to produce a copper target having a larger size than a copper target produced by the conventional method. As mentioned above, a conventional copper target is attached to a support plate to provide sufficient strength. The high strength of the material of the present invention is particularly beneficial because the increased strength can reduce or prevent distortion of the target during the fabrication and/or sputtering process. This approach allows the use of monolithic (non-joined) copper targets and the use of larger target sizes for both joined and monolithic targets. The bonded or monolithic targets of the present invention can be fabricated for many sputtering applications including, but not limited to, 200 mm wafer processing and 300 mm wafer processing.

Although the targets and methods of the present invention are described with specific reference to copper and copper alloys, it is to be understood that the present invention encompasses other materials, including high purity metal and alloy materials. It is particularly beneficial to apply the method to exemplary other materials including aluminum, aluminum alloys, titanium, titanium alloys, tantalum, tantalum alloys, nickel, nickel alloys, molybdenum, molybdenum alloys, gold, gold alloys, Silver, silver alloys, platinum and platinum alloys. The recited alloys preferably contain less than or equal to 10% by weight of alloying elements. As will be appreciated by those of ordinary skill in the art, the temperatures and other values of the methods described below with respect to the copper material may be adjusted based on the particular composition for which the method will be used.

The method of the present invention is generally described with reference to FIG. 1 . In one exemplary processing scheme 10, a material to be processed to form a sputter target is provided in an initial processing step 100. The starting material may be provided in the form of a blank such as the exemplary blank 12 depicted in FIG. 2 . Referring to FIG. 2 , blank 12 includes a bottom surface 14 , a top surface 16 , and includes a thickness of material between bottom surface 14 and top surface 16 , designated T ₁ . Blank 12 may be square or rectangular in shape as shown in FIG. 2, or may include a cylindrical or other shape (not shown). The billet 12 preferably comprises a cast material, although other billet materials are possible. In embodiments where a high purity target is desired, it is particularly preferred that the billet 12 is a cast material, since the cast material can be provided in a very pure form. Typically the composition of the target produced by the method of the present invention is substantially the same as that of the billet; where substantially identical means that the material has no detectable compositional difference.

The texture of the blank 12 material can affect the texture of an article made in accordance with the present invention and/or the difficulty of obtaining the desired final texture of the article. Accordingly, a blank 12 can be provided having an initial texture that facilitates the manufacture of the desired texture in the copper target. Where strong texture is desired in the final article, it is beneficial to provide the blank 12 with a strong texture. However, it should be pointed out that a weak or very weak texture can be produced from a strongly textured billet using an alternative method of the present invention. In addition, blanks with weak texture can be treated according to the method of the present invention to produce targets with strong or extremely strong texture. Blanks with a particular major or major grain orientation can be processed to produce targets with the same or different major or major grain orientations, or without a single major grain orientation.

In a particular aspect, billet 12 comprises a high purity copper material having at least 99.99% copper by weight. In particular applications, blank 12 consists essentially of copper that is 99.99% pure (4N), 99.999% pure (5N), 99.9999% pure (6N) or greater than 6N, eg, 99.99995% by weight copper. The present invention also includes methods wherein the billet 12 contains another high purity metal such as aluminum, gold, silver, titanium, tantalum, nickel, platinum or molybdenum.

Alternatively, billet 12 contains less than 99.99% copper or less than 99.99% other metals as described above. For ease of description, billet 12 will hereafter be referred to as a copper billet, although it should be understood that other metals and their alloys are encompassed by the present invention. In some aspects of the invention, copper blank 12 preferably consists essentially of less than 99.99% by weight copper and at least one alloying element selected from the group consisting of: Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W, Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc, Si, Pt, Nb, Re, Mo and Hf. The total amount of alloying elements in the copper billet is preferably at least 100 ppm by weight - less than or equal to about 10% by weight. In particular aspects, the copper billet preferably contains at least 1000 ppm to less than or equal to about 3 weight percent alloying elements, more preferably less than or equal to about 2 weight percent alloying elements. In particular embodiments, the alloying elements preferably include one or more of Ag, Al, In, Zn, B, Ga, Mg, Sn, Ge, Ti, and Zr.

Referring again to FIG. 1 , the copper blank provided in step 100 is subjected to pretreatment 200 . Pretreatment 200 includes at least one of homogenization, solutionization and hot forging. Suitable temperatures for solutionizing, homogenizing, or hot forging depend on the particular composition of the billet 12, as will be understood by those of ordinary skill in the art. In certain aspects, the invention preferably includes hot forging during pretreatment 200 to form a forged block. Hot forging of copper blank 12 is performed at a temperature of at least about 300°C, preferably at a temperature of at least about 500°C. Preferably, hot forging reduces the initial thickness (T ₁ in FIG. 2 ) of blank 12 by at least about 40%, and in certain instances, preferably at least about 50%.

During pretreatment, hot forging is optionally followed or preceded by additional heat treatment including solutionizing and/or homogenizing the copper material. The heat treatment is carried out at a temperature sufficient to cause solutionization and/or homogenization to occur in the particular composition being treated. This solution/homogenization temperature is preferably maintained for a time sufficient to maximize solution/homogenization of the composition. It should be noted that temperatures sufficient for solutionization or homogenization will result in grain growth resulting in grain sizes beyond the desired range of less than about 100 microns. Therefore, conventional methods of attempting to obtain smaller particle sizes tend to minimize solutionization or homogenization treatments. However, the method of the present invention can reduce the particle size after homogenization/solutionization, thereby obtaining the benefits of solution/homogenization treatment and small particle size at the same time. It is beneficial to solutionize and/or homogenize during the pretreatment step 200 to dissolve any precipitates and/or particles present in the copper billet. Homogenization also reduces or eliminates chemical segregation within billet 12 .

The pretreatment process of the present invention is not limited to a specific sequence of homogenization, solutionization and/or hot forging. In a particular aspect, pretreatment 200 includes homogenizing the copper billet, followed by hot forging, followed by solutionizing. In other cases hot forging is performed after solutionizing. Exemplary preferred pretreatments are set forth below by way of exemplary preferred embodiments of the invention.

In some cases where hot forging is performed during pretreatment 200, the pretreatment additionally includes a quench following, preferably immediately following, the hot forging. Water quenching is preferred, although other quenching methods can be used.

In certain embodiments, hot forging may include an initial heating, and one or more subsequent instances of reheating may be performed. The height drop produced in each forging instance between the initial heating and each subsequent reheat will vary, depending on factors such as the particular composition and forging temperature used. Preferably, ongoing quenching occurs only after final reheating. Exemplary reheating includes reheating the forging block to 1400°F for at least about 10 minutes one or more times after the initial hot forging.

In addition to the processes described above, pretreatment 200 optionally includes an aging treatment. Where the pretreatment includes aging, the billet 12 is preferably machined into a forging block prior to aging. More preferably, aging is carried out as a final process in a pre-treatment stage. In certain cases, aging is used to induce the formation of fine precipitates in the copper. Such induced precipitates have an average diameter of less than about 0.5 microns. In certain applications, it is beneficial to induce precipitates by aging, since such precipitates can promote the development of fine and uniform grains during subsequent processing and can stabilize the grain structure so produced.

Subsequently, the hot forged and/or solutionized block formed in pretreatment 200 is subjected to another processing as shown in FIG. 1 . In one aspect, the processed block is subjected to an equal channel angular extrusion (ECAE) process 310 to form a target blank. Referring to FIG. 3 , an exemplary ECAE device 20 is illustrated. Apparatus 20 includes a mold assembly 22 defining a pair of intersecting channels 24 and 26 . The cross-sections of the intersecting channels 24 and 26 are identical or at least substantially identical, the term "substantially identical" meaning that the channels are identical within tolerances acceptable to the ECAE device. In operation, billet 28 (which may be a forging block as described above) is extruded through passages 24 and 26 . This extrusion causes plastic deformation of the billet layer by layer by pure shear in the thin regions located at the channel cross-section. While it is preferred that channels 24 and 26 intersect at an angle of approximately 90°, it is understood that another tool angle (not shown) may be used. A tool angle (channel intersection angle) of about 90° is preferred because the best deformation (true shear strain) is obtained.

ECAE introduces severe plastic deformation into the forging block material while keeping the block dimensions constant. ECAE is the preferred method for inducing severe strains in metallic materials because it can be used at low loads and pressures to introduce very consistent and uniform strains. In addition, each pass of ECAE can obtain high deformation (true strain ε = 1.17); multiple passes through ECAE equipment can obtain high cumulative strain (N = 4 passes, ε = 4.64); and by applying different deformation paths ( That is, by changing the orientation of the forge between passes through the ECAE apparatus) can be used to create various textures/microstructures within the material.

In an exemplary method of the invention, the strain is sufficient to obtain the desired microstructure (e.g., weak texture and small grain size) within the copper billet or forging block and to produce a uniform stress-strain state throughout the billet. ECAE was performed at the rate and processing temperature. The copper material is passed through the ECAE apparatus several times in various routes and at temperatures equivalent to cold or hot working of the material. The preferred route using more than 20 passes through the ECAE apparatus is "Route D", which corresponds to a constant rotation of the blank 90° before each subsequent pass. Because ECAE routes can affect the structural orientation produced during dynamic recrystallization, one or more specific routes are selected for the deformation pass to induce the desired orientation in the processed material.

In certain applications, the forged block processed in step 200 undergoes at least 4 passes of ECAE in process 310 . Typically, the ECAE process 310 includes 4-8 passes, preferably 4-6 passes. Since dynamic recrystallization is induced mechanically, this exemplary number of passes is generally found to be sufficient to induce grain refinement to submicron size (where submicron refers to an average particle size of less than 1 micron).

Typically, 1-3 passes of ECAE each successively form defects (microstrips; shear bands, dislocation arrays, etc.). During these initial passes, thermodynamic rearrangements can occur to generate cells and subgrains and induce grain boundary misorientation. Prior to ECAE, the texture strength of the material affects the strength generated during the first 3 passes, typically strong initial textures become randomized after more passes relative to materials with weak initial textures. Subsequent passes (the fourth pass and any further passes) create dynamically recrystallized submicron particle sizes by inducing an increase in the number of high-angle boundaries. During dynamic recrystallization, the newly formed grains gradually acquire a weaker texture and become more equiaxed.

In some applications, the mold of the heated ECAE apparatus may be used to heat the blank 28 during the ECAE pass. Preferably, the mold is heated to a temperature lower than the minimum static recrystallization temperature (or, referred to as the minimum recrystallization temperature) of the processed copper material, more preferably to about 125 to about 350°C.

During ECAE processing 310, intermediate anneals are optionally performed between some or all of the ECAE passes. The intermediate annealing can be performed below the static recrystallization onset temperature, at or near the static recrystallization onset temperature (defined as the lowest temperature at which recrystallization of the material being processed begins to be induced), or within a temperature range that constitutes complete static recrystallization. The temperature at which the intermediate anneal is performed affects the size and orientation of the grains and thus can be used to promote the desired texture in a given situation.

Intermediate annealing at a temperature that produces complete static recrystallization results in increased weakening of the texture during subsequent ECAE passes. Annealing at temperatures below the onset of static recrystallization produces recovery (stress relief), which can also lead to changes in texture strength and orientation. The reorientation effect is maximized when the subcrystallization temperature anneal is performed between one or more of the first 4 passes, and becomes less pronounced when performed between passes after the fourth. Intermediate annealing at the onset temperature of static recrystallization results in changes in both texture (strength and/or orientation) and some recrystallization. Repeating the intermediate annealing between successive passes has an enhanced effect over the described single annealing case effect.

In certain applications of the invention, it is preferred to perform any intermediate annealing at a temperature and time below that which would result in static recrystallization of the material being processed. It is beneficial to perform the intermediate anneal at a temperature below that which would induce static recrystallization to minimize surface cracking and increased microstructural uniformity. In the case of ingots subjected to ECAE containing high purity copper, it is preferred to perform the intermediate annealing at a temperature of from about 125°C to about 225°C for more than about 1 hour. This enables ECAE processing 310 to produce a high purity copper material with an extremely uniform and small particle size, eg, from submicron particle size to about 20 microns on average.

In aspects of the invention, in the case of copper-containing alloys of the wrought material, the subcrystallization temperature intermediate annealing performed during ECAE processing 310 preferably includes a temperature of about 150°C to about 325°C, preferably maintained at this temperature for at least 1 hour. This sub-recrystallization temperature annealing process produces a copper alloy material with an average grain size below 1 micron.

High purity copper and copper alloy materials produced by the ECAE method described above have increased hardness relative to materials produced by conventional processing methods. Table 1 shows the resulting hardness of 6N copper and various copper alloys processed according to the method of the invention relative to the corresponding material prior to ECAE. Figure 4 compares the yield strength and ultimate tensile strength of high purity copper and various copper alloys processed according to the method of the present invention relative to 6N copper having a grain size of 40 microns and various back plate materials.

Table 1: Effect of ECAE treatment on material particle size and hardness Pre-ECAE material (particle size 30-50 microns) Hardness (Vickers) Average particle size after ECAE Hardness after ECAE (Vickers) increased hardness 6N copper 48.44HV 5 microns 72.2HV 49% 6N Cu+0.8%Ag 73.02HV 4 microns 89.88HV twenty three% 6N Cu+0.8%Ag 73.02HV 0.35 microns 172.4HV 136% 6N Cu+0.5%Sn 75HV 4 microns 104.56HV 39.4% 6N Cu+0.5%Sn 75HV 0.35 microns 182HV 142%

As shown in FIG. 1 , after pretreatment 200 , the copper material is subjected to another process route including a rolling process to manufacture a target semi-finished product. The rolling treatment 330 preferably includes cold rolling the ingot produced by the pretreatment 220 to a total reduction of at least 60%, preferably 60-85%. Cold rolling includes more than 4 passes, preferably more than 8 passes, more preferably 8-16 passes. Preferably, each of the initial 4 passes is used to reduce the thickness of the block by about 5% to about 6% throughout the rolling process. In addition, it is preferred that the final 4 passes each provide a thickness reduction of about 10 to about 20%. The relatively small reduction during the initial 4 passes can mitigate or prevent cracking during the rolling process. Rolling can produce small grain sizes in the resulting cold rolled high purity copper or copper alloy material.

As shown in FIG. 1 , instead of the above process route, process route 320 may be performed. Route 320 applies a combination of cold rolling and equal channel angular extrusion techniques. Where another processing route 320 is used, it is preferred to perform ECAE and subsequent cold rolling treatment on the hot forged ingot produced by pretreatment 200 . However, it is to be understood that the invention contemplates cold rolling prior to ECAE or both before and after ECAE.

The ECAE portion of process 320 includes the ECAE processing methods described above. Subsequently, the ECAE extruded material is cold rolled to a reduction of less than about 90% to form a semi-finished product. In certain instances, the cold rolling portion of route 320 preferably produces a reduction of at least about 60%. The cold rolling process of the ECAE extruded material includes the rolling process described above with respect to the rolling process 330 . In a particular aspect, route 320 combines rolling and forging to produce a total drop of at least 60% but less than 90%. Alternatively, a forging process can be used without rolling to produce the required 60-90% drop.

It is beneficial to combine ECAE with a subsequent rolling and/or forging process, as this treatment can induce the desired grain orientation in the copper material. The induced orientation includes or includes a major grain orientation. Rolling and/or forging are used to form strong or extremely strong textures in the copper articles of the present invention. In some aspects, the strong texture formed by post-ECAE rolling/forging will not be a (220) texture.

As shown in FIG. 1 , the resulting semi-finished product containing copper or copper alloy material is subjected to a final target formation process 500 and optionally to an additional heat treatment 400 prior to final target formation 500 . Optional thermal treatment process 400 includes annealing at a temperature and time below that which induces the onset of static recrystallization. Low temperature annealing is performed below the minimum temperature of static recrystallization, also known as recovery annealing. Recovery annealing, or optionally no annealing, is beneficial for maintaining an extremely small particle size. Such low temperature annealing or no annealing produces a semifinished product with an average particle size of less than about 1 micron.

Alternatively, the semi-finished product is subjected to a temperature at or above the minimum temperature to induce recrystallization for a period of time sufficient to develop the final particle size distribution within the semi-finished product. Although static recrystallization increases particle size, this increase can be minimized by performing annealing close to the minimum temperature of recrystallization for a minimum time to produce the desired amount of recrystallization (partial or complete recrystallization). For copper alloys, it is preferred to perform the recrystallization anneal at about 350 to about 500°C for about 1 to about 8 hours. For high purity copper, it is preferred to perform the recrystallization anneal at about 225 to about 300°C for about 1 to about 4 hours.

Figures 5 and 6 illustrate the particle size and distribution of 6N copper with an average particle size of about 6 microns produced using ECAE followed by annealing at 250°C for 5 hours according to the method of the present invention. Figure 7 illustrates the grain size evolution in relation to the annealing treatment for a copper alloy with 0.53% Mg that has been subjected to 6 passes of ECAE via route D prior to annealing. Figure 8 illustrates the particle size and distribution of the Cu/0.53%Mg alloy of Figure 7 after annealing at 300°C for 2 hours. Figures 9 and 10 illustrate the particle size and distribution of the Cu/0.53%Mg alloy in Figure 7 after annealing at 450°C for 1.5 hours, analyzed using EBSD/SEM (Figure 9) and optical microscopy (Figure 10).

It is to be noted that the semifinished product produced in optional steps 310 , 320 or 330 is subjected to an aging treatment (not shown) without or after heat treatment stage 400 . Where aging is used, aging is preferably performed at a temperature below about 500°C. As noted above, it is beneficial to perform the aging step to increase the strength of the copper or copper alloy blank by inducing fine precipitates with an average precipitate size of less than about 0.5 microns.

The high-purity copper or copper alloy semi-finished products produced by the method of the present invention are subjected to final target forming 500 to produce monolithic targets or to produce bonded targets (wherein "bonded target" refers to a sputtering target connected to a support such as a support plate ).

Where the final target formed in process 500 is a monolithic target, final target shaping includes, for example, machining the semi-finished product to form the desired target shape. In case the targets produced by the method of the present invention are to be used in semiconductor wafer processing, the final shaping step 500 comprises producing targets with dimensions suitable for processing 200 mm wafers or suitable for processing 300 mm wafers. For example, an exemplary monolithic copper or copper or copper alloy target of the present invention for processing a 200 mm semiconductor wafer has a sputtering surface diameter of 13.7 inches, an opposing surface (back) diameter of 16.6 inches, and a thickness of about 0.89 inches. A corresponding target for processing a 300 mm wafer has a sputtering face diameter of 17.5 inches, a backside diameter of 20.7 inches, and a thickness of about 1.0 inches. The monolithic targets formed by the method of the present invention are preferably planar targets, although other target shapes and other dimensions are also contemplated.

To maximize target strength, monolithic targets produced according to the methods of the present invention preferably have a particle size of less than or equal to about 50 microns. A monolithic target of the present invention having a submicron particle size has yield strength, ultimate tensile strength (UTS) and hardness at least about 50% greater than a target of substantially the same composition having an average particle size of 30 microns. Monolithic copper targets having an average particle size of 1 to less than about 20 microns made in accordance with the present invention have at least 10% increased strength over conventional copper targets. For extremely large monolithic targets or in applications where maximum target strength is required, it is preferable to fabricate the monolithic target without the heat treatment step 400 . Therefore, the resulting monolithic target can maintain the small particle size produced in the previous process. For example, where rolling and/or ECAE are applied to produce submicron particle sizes, the submicron particle size can be maintained in the final monolithic target, thereby maximizing target strength. In another aspect, the thermal treatment step 400 is used during processing to produce a monolithic target that can produce a final particle size distribution in the resulting monolithic target such that the average particle size ranges from about 1 to about 20 microns .

Where the target fabricated in step 500 is a joined target, target formation includes a joining step in addition to any machining to form the desired target shape. The joining process involves joining the semi-finished product formed by the above-mentioned processing method with a support such as a support plate. For example, exemplary support plates include aluminum and/or copper. Exemplary backing plate materials are CuCr, Al 2024 and Al 6061 T4. Joining processes include one or more of isostatic pressing (hipping), rolling, cladding, welding, explosive joining, frictionless forging, diffusion bonding, or other methods known to those of ordinary skill in the art. The connection produces a connection with a yield strength of at least about 10 ksi. In certain instances, the connection yields a joint strength of greater than or equal to about 15 ksi, and in certain applications, a joint strength of equal to or greater than 30 ksi.

Copper articles with extremely uniform and small grain sizes can be produced using the various processing methods described above. Often, the particle size produced averages from submicron grains to the vicinity. This small particle size enables very high bonding strengths because high temperature bonding methods can be used. In the case of making bonded targets, heating (thermal treatment 400) may be combined with bonding in the target formation process.

The joining of high purity copper targets according to the method of the present invention is preferably performed at a temperature of less than or equal to about 325° C. for a period of less than or equal to about 4 hours to minimize grain growth in the target. Although some grain growth occurs during high temperature bonding, the initial extremely fine grain size allows some grain growth to occur without resulting in the larger grain sizes observed in targets formed using conventional processing methods. The resulting particle size of 1 to about 20 microns in the final bonded target of the present invention results in an increase in strength of at least 10% over conventional copper targets.

Formation of the bonded copper alloy target is preferably performed at a temperature and time below that which produces complete static recrystallization. Such attachment preferably involves performing attachment at a temperature below about 400°C for 4 hours, more preferably below 350°C for 1-4 hours. Copper alloy targets with an average grain size of less than 1 micron can be formed using these joining conditions.

Alternatively, the connection includes temperatures that can cause the copper alloy to recrystallize. During a joining that involves temperatures above the minimum static recrystallization temperature of the particular alloy, it is desirable to minimize the temperature and time of joining to minimize grain growth. The recrystallization that occurs during the joining process is preferably such that an average particle size of 1 to about 20 microns is produced in the copper alloy. Such heat treatment for complete recrystallization is preferably carried out at a temperature of about 200°C for at least about 1 hour, preferably 350-500°C for a time greater than 1 hour.

As an alternative to combining the heating and joining process, heat treatment is performed either before the joining step (ie, heat treatment 400 ) or after the joining step. It is beneficial to combine joining and heat treatment to increase joint strength and recrystallize the copper or copper alloy material.

Bonded copper and bonded copper alloy targets formed according to the method of the present invention have improved bond strength relative to bonded targets formed using conventional methods. In some aspects of the invention, diffusion bonding is preferred for bonding the target to the support plate. In the case of target blanks with sub-micron grain sizes, very high-strength diffusion connections can be produced due to the increased diffusion capacity of the ultrafine grains. The resulting diffusion bond has a yield strength of 15 ksi or greater, and in some cases the yield strength can equal or exceed 30 ksi. Additional advantages of joining the copper and copper alloy targets of the present invention include increased resistance to twisting and reduced buckling of the targets relative to conventional targets. Use of the targets of the present invention for sputtering applications can provide improved quality films in which there are fewer bound particles, and can provide better uniformity of film thickness and thus improved uniformity of electrical resistance. In addition, the use of targets formed according to the method of the present invention for semiconductor processing provides wafer-to-wafer improved uniformity of film thickness and resistance.

Monolithic high purity copper and copper alloy targets formed according to the method of the present invention have a lifetime that is at least 30% longer, and typically 40% longer, relative to conventionally bonded copper and copper alloy targets formed by other methods. The availability of a monolithic copper target makes it possible to avoid delamination (separation from the support plate) which occurs with conventionally bonded targets. In addition, monolithic targets according to the invention have increased resistance to target twisting, reduced bowing, reduced particle generation in thin films sputtered with such targets, improved uniformity of film thickness and resistivity. In addition, monolithic targets according to the present invention have improved uniformity of film thickness and resistivity from wafer to wafer.

The examples provided below are exemplary preferred embodiments of the invention. It is to be understood that the invention includes additional embodiments and is not limited to the specific examples provided.

Embodiment 1: Manufacture high-purity copper monolithic sputtering target

A cast copper billet measuring 6 inches in diameter, 11 inches in length, and 6N pure was heated in an air furnace to a temperature of about 990°F and held for about 60 minutes. The billet is then hot forged to a final height reduction of 55-75%, immediately water quenched, using silica or graphite foil during the forging process. The ingot was then cold rolled for 16 passes, quenched after the initial 8 passes, for a total reduction of about 60 to about 80%. Cracking during cold rolling is prevented by performing the first 4 cold rolling passes with a reduction of about 5 to about 6% per pass. 13-16 passes were performed to produce a reduction of about 10 to about 11% per pass to obtain a small particle size. After cold rolling, the blank is recrystallized by heating to about 480°F for about 120 minutes. The semi-finished product is machined to make the final target. The resulting high purity copper monolithic target has an average particle size of less than 50 microns while having a uniform particle distribution throughout the target.

Figure 11 illustrates the sampling locations of the resulting monolithic target for analysis. The thickness of the target is 0.89 inches. The particle sizes measured at the points indicated on the sputtered surface and their average values are given in Table 2.

Table 2: Particle size measurement data at the target surface Location 1 2 3 4 5 6 7 8 9 average particle size 38 45 45 38 38 53 38 38 53 43

Table 3 presents the measured particle sizes at the indicated points of the depth plane in FIG. 11 , as well as the average of these measurements. Table 4 illustrates the texture determined by the indicated target points of the targets identified in FIG. 11 .

Table 3: Particle size measurement data at the marked points in the target depth 2 4 5 7 average 0.250” 53 38 45 45 45.3 0.460" 45 38 45 45 43.3 0.700” 45 45 45 45 45

Table 4: Texture of target microstructure at indicated points depth Location (111) (200) (220) (113) 0.00" 2 24.0% 20.9% 25.0% 30.1% 4 23.9% 22.3% 23.7% 30.1% 5 21.5% 20.6% 26.2% 31.7% 7 23.5% 20.5% 24.2% 31.7% 0.250” 2 22.5% 16.9% 30.8% 29.7% 4 24.6% 16.7% 28.7% 30.2% 5 18.0% 15.2% 39.4% 27.5% 7 24.5% 15.2% 31.2% 28.0% 0.460” 2 21.5% 17.6% 35.1% 25.8% 4 19.0% 17.6% 42.4% 21.0% 5 16.8% 15.9% 41.2% 26.2% 7 20.5% 17.2% 33.1% 29.3% 0.700" 2 21.9% 20.5% 26.0% 31.6% 4 23.0% 20.8% 25.8% 30.4% 5 22.2% 20.8% 27.2% 29.8% 7 22.4% 22.4% 21.1% 34.0%

Another embodiment of forming a high purity target as described in the previous examples, except that ECAE is introduced into the process. ECAE is performed before cold rolling to reduce the particle size present in the cast slab. The resulting targets were analyzed as indicated above for the above examples. The target has an average particle size throughout the target of less than 15 microns.

Embodiment 2: Manufacture copper alloy monolithic sputtering target

A billet of copper alloy having less than 10% Ag, Sn, Al or Ti is heated and maintained at a temperature of about 900 to about 1500°F for about 45 minutes. The billet is then hot forged to produce a final reduction of at least about 50%. Reheat some forging billets (depending on the alloy) for at least 10 minutes during forging. Immediately after final forging, the forged billet is water quenched. The ingot is cold rolled to a reduction of at least about 60% to form a semi-finished product which is recrystallized by heating to a temperature of from about 750 to about 1200°F for 120 minutes. The recrystallized blank is machined to form a monolithic target. Each target has an average particle size of about 15 to about 50 microns.

A specific target of a copper alloy with 0.3 atomic % Al was formed from a billet with a diameter of 6 inches and a length of 11 inches. Initially, the billet was heated at 1400°F for 1 hour and initially forged to a height of 6 inches. After the initial forging, the billet was reheated at 1400°F for 15 minutes, and then the billet was forged to a height of 3 inches. Immediately after the final forging, the forged block is water quenched. Then, cold rolling consisting of 17 passes was performed according to the rolling schedule shown in Table 5, thereby forming a rolled semi-finished product.

The blank is annealed at about 825°F for about 120 minutes after rolling and forms the final monolithic target. Analysis of the target surface (according to the surface points shown in Figure 11) revealed a uniform composition and an average particle size of 37 microns. The particle size non-uniformity was 8.6% (1-σ).

Table 5: Rolling schedule for Cu-0.3 at% Al road Direction (degrees) ΔHeight (inches) height (inches) % reduction 1 0 0.1 2.9 3.3 2 135 0.1 2.8 3.4 3 270 0.1 2.7 2.6 4 45 0.1 2.6 3.7 5 180 0.1 2.5 3.8 6 315 0.1 2.4 4.0 7 90 0.1 2.3 4.2 8 225 0.1 2.2 4.3 9 0 0.13 2.07 5.9 10 135 0.13 1.94 6.2 11 270 0.13 1.81 6.7 12 45 0.13 1.68 7.1 13 180 0.13 1.55 7.7 14 315 0.13 1.42 8.3 15 90 0.13 1.29 9.1 16 225 0.13 1.16 10.0 17 Freedom Road (One free pass)

Example 3: Manufacture of Copper Alloy Diffusion Bonded Sputtering Target

A copper alloy billet was provided and processed as described in Example 2, except that it was cold rolled to a reduction of at least about 50%. The cold-rolled semi-finished product was joined to the CuCr support plate at a joining temperature of about 450° C. for about 120 minutes. Recrystallization of the alloy occurs during the joining process. The attached target has a particle size of less than about 30 microns and an attachment strength of up to about 30 ksi.

Embodiment 4: Using ECAE to manufacture high-purity copper sputtering target

Provide cast copper billets with a purity of at least 99.9999%. The high purity copper billet is hot forged at a minimum temperature of about 500° C. while decreasing in height by at least about 40%, thereby forming a forged block. The ingot is solutionized by heating the ingot to at least about 500°C and maintaining this temperature for at least about 1 hour. Immediately after heat treatment the solutionized block was water quenched and extruded using 4-6 passes of equal channel angular extrusion (ECAE) according to route D (90 degree block rotation between successive passes) to produce submicron Microstructure. An intermediate anneal at a temperature of about 125°C to about 225°C is performed for at least about 1 hour between some or all of the ECAE passes. The extruded high-purity copper block is cold-rolled to a reduction of at least 60% to form a target blank which is formed into a monolithic or joined target.

A monolithic target blank is machined to produce the final target. Direct machining of the semi-finished product produces targets with sub-micron particle sizes. Recrystallization is performed to produce monolithic targets having an average particle size of 1 to about 20 microns.

The semi-finished product for connecting the target is diffusion bonded to the carrier plate. Diffusion bonding is performed at a temperature below 350° C. for less than 4 hours. The joint yield strength is greater than about 15 ksi. The attachment target has a particle size from submicron to about 20 microns. The submicron target has about a 50% increase in strength relative to conventional targets. Bonded targets having a particle size of 1 to about 20 microns have at least a 10% increase in strength relative to conventional copper targets. After diffusion bonding at 250° C. for 2 hours, the particle sizes at different locations throughout the 6N copper target (see FIG. 11 for sampling information) are shown in Table 6. The average particle size was 11.37 microns with a standard deviation of 6.97% (1-σ).

Table 6: Particle Size (microns) of 6N Diffusion Bonded Targets Location top surface middle face bottom surface 1 13 11 11 2 11 13 11 3 11 11 11 4 13 11 11 5 11 11 11 6 11 11 13 7 11 11 13 8 11 11 11 9 11 11 11

Table 7 presents the three-point hardness measurements obtained from the top and bottom surfaces of the targets in Table 6. The average hardness was 53.3HB with a standard deviation of 2.18% (1-σ).

Table 7: Hardness (HB) of 6N diffusion bonded targets Location top surface bottom surface 1 53.4/55.1/53.4 51.8/51.8/50.3 2 50.3/51.8/51.8 53.4/53.4/51.8 3 53.4/55.1/51.8 53.4/53.4/53.4 4 53.4/55.1/53.4 50.3/51.8/51.8 5 55.1/55.1/53.4 51.8/51.8/51.8 6 53.4/55.1/53.4 51.8/53.4/50.3 7 55.1/55.1/53.4 53.4/53.4/51.8 8 53.4/53.4/51.8 51.8/53.4/51.8 9 53.4/53.4/51.8 53.4/53.4/51.8

Embodiment 5: Adopt ECAE to manufacture copper alloy sputtering target

A copper billet of a copper-containing alloy alloyed with 1000 ppm to less than or equal to about 10% Ag, Al, In, Zn, B, Ga, Mg, Sn, Ge, Ti, or Zr is provided. The billet is hot forged at a temperature of at least about 500° C. while decreasing in height by at least about 40%, thereby forming a forged block. The forged block is solutionized by heating the block to at least about 500° C. and maintaining that temperature for at least about 1 hour to form a solutionized block. The solutionized mass was water quenched immediately after solutionization.

The solutionized mass was extruded by performing 4-6 passes of ECAE. According to Route D, the solutionized block was rotated 90 degrees between each pass. Between some ECAE passes, an intermediate anneal is performed at a temperature of about 150°C to about 325°C for at least 1 hour. The ECAE extruded block was cold rolled to a reduction of at least about 60% to form a copper alloy semi-finished product.

A first monolithic copper alloy target was fabricated by machining a copper alloy blank manufactured as described to form a monolithic target. The average particle size of the first monolithic target is less than 1 micron. Additionally, the first monolithic copper alloy target has a yield strength, ultimate tensile strength (UTS), and hardness that are at least about 50% greater than a target having substantially the same elemental composition and having an average grain size of 30 microns.

A second monolithic copper alloy target was produced by heat treating the copper alloy blank produced as described above. Heat treatment was performed at a temperature of 350° C. for about 1 hour. The second target has an average particle size of 1 to about 20 microns, is substantially free of precipitates (substantially free of precipitates means no detectable precipitates), has no detectable segregation, and has a maximum void size of less than 1 micron.

A first bonded copper alloy target was produced by diffusion bonding a copper alloy semi-finished product produced as described to a support plate. Diffusion bonding is performed at a temperature below 350° C. for 1-4 hours. The average grain size of the first bonded alloy target is less than 1 micron.

A second bonded copper alloy target was fabricated by diffusion bonding the copper alloy blank manufactured as described above to the support plate at a bonding temperature of about 350 to about 500°C for at least 1 hour. The second bonded copper alloy target is substantially recrystallized, the target having an average particle size of about 1 to about 20 microns.

Claims (109)

1. A copper-containing sputtering target, comprising: At least 99.99% copper by weight; an average particle size of at least 1 micron to less than or equal to about 50 microns; and The target has a yield strength of greater than or equal to about 15 ksi. 2. The target of claim 1, wherein the target has a hardness of at least 40 HB. 3. The target of claim 1 having an ultimate tensile strength that is at least 15% greater than a target having an average particle size of 50 microns and having substantially the same elemental composition. 4. The sputtering target of claim 1 having a hardness at least 15% greater than a target having an average particle size of 50 microns and having substantially the same elemental composition. 5. The sputtering target of claim 1 having a yield strength at least 10% greater than a target having an average particle size of 50 microns and having substantially the same elemental composition. 6. The sputtering target of claim 1, wherein the target is monolithic and has a sputter lifetime at least 30% longer than another bonded target having an average particle size of 50 microns and having substantially the same elemental composition. 7. The target of claim 1, wherein the target contains at least 99.999% copper by weight. 8. The target of claim 1, wherein the target contains at least 99.9999% by weight copper. 9. The target of claim 1, wherein the target contains at least 99.99995% copper by weight. 10. The target of claim 1, wherein the target has a particle size uniformity having a nonuniformity of less than or equal to 20%. 11. The target of claim 10, wherein the non-uniformity is less than 15% (1-[sigma]). 12. The target of claim 1, wherein the target has a particle size uniformity with a standard deviation of less than or equal to 10% (1-[sigma]). 13. The target of claim 1, wherein the target is diffusion bonded to the support plate, the diffusion bond having a bond yield strength of greater than 10 ksi. 14. The target of claim 13, wherein the bond yield strength is greater than or equal to about 15 ksi. 15. The target of claim 1, wherein the average particle size is from about 5 to about 20 microns. 16. A copper alloy sputtering target consisting essentially of: less than or equal to about 99.99% by weight copper; At least one alloying element selected from the group consisting of: Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W , Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc, Si, Pt, Nb, Re, Mo and Hf, at least one alloying element present in the target The total amount is at least 100 ppm - less than 10% by weight; the target has a hardness of at least 40 HB. 17. The target of claim 16 having an average particle size of less than 1 micron. 18. The target of claim 17, having a standard deviation of particle size uniformity throughout the target of less than or equal to about 15% (1-σ). 19. The target of claim 17, having a standard deviation of particle size uniformity throughout the target of less than or equal to about 10% (1-σ). 20. The target of claim 16, having a standard deviation of hardness uniformity throughout the target of less than about 5% (1-σ). 21. The target of claim 20, wherein the hardness uniformity standard deviation is less than about 3.5% (1-sigma). 22. The target of claim 16, wherein the target is monolithic. 23. The target of claim 16 diffusion bonded to the support plate, the diffusion bond having a bond yield strength of greater than about 15 ksi. 24. The target of claim 16 having an orientation distribution function (ODF) of less than about 15 disorder. 25. The target of claim 16 having an orientation distribution function (ODF) of less than about 5 order disorder. 26. The target of claim 16 having a major grain orientation other than (220). 27. The target of claim 16, wherein the at least one alloying element is selected from the group consisting of Ag, Al, In, Zn, B, Ga, Mg, Sn, Ge, Ti, and Zr. 28. The target of claim 16, wherein the total amount of alloying elements is from about 1000 ppm to less than about 2%. 29. A copper alloy sputtering target consisting essentially of: less than or equal to about 99.99 wt% copper; At least one alloying element selected from the group consisting of: Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W , Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc, Mo, Si, Re, Pt, Nb and Hf, at least one alloying element present in the target The total amount is at least 100 ppm to less than 10% by weight; the target has an average particle size of 1 to about 20 microns, with a standard deviation of particle size uniformity throughout the target of less than about 15% (1-σ). 30. The target of claim 29, wherein the particle size uniformity standard deviation is less than about 10% (1-sigma). 31. The target of claim 29, wherein the target has a hardness of at least about 40 HB. 32. The target of claim 29 having a hardness uniformity comprising a 1-sigma hardness standard deviation of less than about 5% throughout the target. 33. The target of claim 29, wherein the target is monolithic. 34. The target of claim 29 diffusion bonded to the support plate, the diffusion bond having a bond yield strength of greater than about 15 ksi. 35. The target of claim 29 having an orientation distribution function (ODF) of less than about 15 disorder. 36. The target of claim 29 having an orientation distribution function (ODF) of less than about 5 order disorder. 37. The target of claim 29 having a major grain orientation other than (220). 38. The target of claim 29, wherein the at least one alloying element is selected from the group consisting of Ag, Al, In, Zn, B, Ga, Mg, Sn, Ge, Ti, and Zr. 39. The target of claim 29, wherein the total amount of alloying elements is from about 1000 ppm to less than about 2%. 40. A monolithic sputtering target consisting essentially of copper and alloying elements in a total amount of less than or equal to 10% by weight. 41. The monolithic target of claim 40, wherein the total amount of alloying elements comprises at least one element selected from the group consisting of: Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni , In, Zn, B, Ga, Mn, Sn, Ge, W, Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc, Mo, Si, Re, Pt , Nb and Hf. 42. The monolithic target of claim 41, wherein the at least one element is selected from the group consisting of Ag, Al, Sn and Ti. 43. The monolithic target of claim 40, wherein the total amount of alloying elements is less than or equal to about 2 weight percent. 44. The monolithic target of claim 40 comprising at least 99.99% by weight copper. 45. The monolithic target of claim 40, wherein the target comprises a circular shape having a thickness of about 1 inch. 46. The monolithic target of claim 40 having an average particle size of from about 15 to about 50 microns. 47. A bonded sputtering target consisting essentially of copper and alloying elements in a total amount of less than or equal to 10% by weight. 48. The connection target of claim 47, wherein the total amount of alloying elements comprises at least one element selected from the group consisting of: Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W, Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc, Mo, Si, Re, Pt, Nb and Hf. 49. The connection target of claim 48, wherein the at least one element is selected from the group consisting of Ag, Al, Sn and Ti. 50. The connection target of claim 47, wherein the total amount of alloying elements is less than or equal to about 2 weight percent. 51. The connection target of claim 47 comprising at least 99.99% copper by weight. 52. The connection target of claim 47, wherein the target comprises a circular shape. 53. The attachment target of claim 47 having an average particle size of less than about 100 microns. 54. The attachment target of claim 53, wherein the average particle size is from about 15 to about 50 microns. 55. The attachment target of claim 53, wherein the average particle size is less than about 30 microns. 56. The bonded target of claim 47, wherein the target is diffusion bonded to the support plate with a bond strength of at least about 15 ksi. 57. The attachment target of claim 56, wherein the attachment strength is at least about 30 ksi. 58. The connection target of claim 56, wherein the support plate is a CuCr support plate. 59. A method of forming a monolithic sputtering target comprising: providing a copper billet consisting essentially of copper and one or more alloying elements in a total amount of less than or equal to 10% by weight; heating the billet to at least about 900°F and maintaining that temperature for at least about 45 minutes; hot forging the billet to reduce the height by at least about 50%, thereby forming a forged block; cold rolling the ingot to a reduction of at least about 60%, thereby forming a semi-finished product; heating the intermediate product to induce recrystallization and form a final particle size distribution having an average particle size of less than about 100 microns; and The semi-finished product is formed into a monolithic target shape. 60. The method of claim 59, further comprising water quenching after hot forging. 61. The method of claim 59, wherein the one or more alloying elements comprise one or more elements selected from the group consisting of Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W, Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc, Mo, Si, Re, Pt, Nb and Hf. 62. The method of claim 61, wherein the one or more alloying elements are selected from the group consisting of Ag, Al, Sn and Ti. 63. A method of forming a monolithic sputtering target comprising: providing a copper billet comprising at least 99.99% copper by weight; heating the billet to a temperature of at least about 900°F and maintaining the temperature for at least about 45 minutes; hot forging the billet to reduce the height by at least about 50%, thereby forming a forged block; cold rolling the ingot to a reduction of at least about 60%, thereby forming a semi-finished product; heating the intermediate product to induce recrystallization and form a final particle size distribution having an average particle size of less than about 100 microns; and The semi-finished product is formed into a monolithic target shape. 64. The method of claim 63, wherein the average particle size is less than or equal to about 50 microns. 65. The method of claim 57, wherein the average particle size is less than or equal to about 15 microns. 66. The method of claim 57, further comprising equal channel angular pressing prior to cold rolling. 67. A method of forming a bonded sputtering target comprising: providing a copper billet comprising at least 99.99% copper by weight; heating the billet to at least about 900°F and maintaining that temperature for at least about 45 minutes; hot forging the billet to reduce the height by at least about 50%, thereby forming a forged block; cold rolling the ingot to a reduction of at least about 50%, thereby forming a semi-finished product; and Attach the semi-finished product to the support plate. 68. The method of claim 67, wherein the joining is performed at a temperature that induces recrystallization and results in a final particle size distribution having an average particle size of less than about 100 microns. 69. The method of claim 67, wherein the linking produces a link having a strength of at least 15 ksi. 70. The method of claim 67, wherein hot forging comprises: warm up; partial altitude drop; and At least one reheat and additional height reduction. 71. The method of claim 67, further comprising water quenching after hot forging. 72. A method of forming a bonded sputtering target comprising: providing a copper billet consisting essentially of copper and one or more alloying elements in a total amount of less than or equal to 10% by weight; heating the billet to a temperature of at least about 900°F and maintaining the temperature for at least about 45 minutes; hot forging the billet to reduce the height by at least about 50%, thereby forming a forged block; cold rolling the ingot to a reduction of at least about 50%, thereby forming a semi-finished product; and Attach the semi-finished product to the support plate. 73. The method of claim 72, wherein the joining is performed at a temperature that induces recrystallization and results in a final particle size distribution having an average particle size of less than about 100 microns. 74. The method of claim 72, wherein the one or more alloying elements comprise one or more elements selected from the group consisting of Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W, Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc, Mo, Si, Re, Pt, Nb and Hf. 75. The method of claim 74, wherein the one or more alloying elements are selected from Ag, Al, Sn, and Ti. 76. The method of claim 72, wherein the bonding comprises diffusion bonding resulting in a bond having a strength of at least 15 ksi. 77. The method of claim 72, wherein the hot forging comprises: warm up; partial height reduction; and At least one reheat and additional height reduction. 78. The method of claim 72, further comprising equal channel angular pressing prior to cold rolling. 79. A method of forming a copper-containing sputter target comprising: providing Cu billets with a purity of at least 99.99% copper; hot forging the copper billet at a temperature greater than 300°C to reduce the height by at least about 40%, thereby forming a forged block; water quenching the forging block; Carry out the extrusion process, including: Pass the forging block through equal channel angular extrusion (ECAE) at least 4 times; and heat treatment comprising one or two intermediate anneals between at least some of the at least 4 passes and heating the ECAE die to about 125 to about 225°C during the extrusion process; After the extrusion process, cold rolling to a reduction of less than 90% to form a semi-finished product; and This semi-finished product is shaped into a target. 80. The method of claim 79, further comprising solutionizing the forge prior to water quenching, solutionizing comprising heating the forge to at least about 500°C and maintaining the temperature for at least about 60 minutes. 81. The method of claim 79, wherein the extrusion process includes intermediate annealing at a temperature of about 125 to about 225°C for greater than about 1 hour. 82. The method of claim 79, further comprising heating the semi-finished product to recrystallize the copper and form a final particle size distribution within the semi-finished product, the final particle size distribution having an average particle diameter of about 1 to about 20 microns; wherein the semi-finished product is formed into Targeting includes forming a monolithic target. 83. The method of claim 79, wherein forming the intermediate product into a target comprises forming a link target. 84. The method of claim 83, wherein forming a bonded target comprises bonding the target to a support plate at a temperature of less than or equal to about 325° C. for less than about 4 hours, the bonding comprising isostatic pressing, roll cladding , at least one of welding and diffusion bonding. 85. The method of claim 84, wherein the joining comprises diffusion joining to form a joint having a yield strength of at least about 10 to about 15 ksi. 86. The method of claim 79, wherein the average particle size is from 1 to about 50 microns. 87. The method of claim 86, wherein the average particle size is from 5 to about 20 microns. 88. The method of claim 79, wherein there is a uniform particle size distribution throughout the bulk of the semi-finished product, the uniform particle size having a standard deviation of less than 15% (1-[sigma]). 89. The method of claim 88, wherein the particle size uniformity standard deviation is less than about 10% (1-σ). 90. The method of claim 79, wherein the copper billet has a purity of at least about 99.999% copper. 91. The method of claim 79, wherein the copper billet has a purity of at least about 99.9999% copper. 92. The method of claim 79, wherein the copper billet has a purity of at least about 99.99995% copper. 93. The method of claim 79, wherein the at least 4 passes consist of 4-6 passes. 94. A method of forming a copper alloy sputtering target comprising: Providing a Cu billet consisting essentially of less than 99.99% copper and at least one alloying element selected from the group consisting of: Cd, Ca, Au, Ag, Be, Li, Mg, Al, Pd, Hg, Ni, In, Zn, B, Ga, Mn, Sn, Ge, W, Cr, O, Sb, Ir, P, As, Co, Te, Fe, S, Ti, Zr, Sc and Hf, at least one of Cu blanks The total amount of alloying elements is at least 100 ppm to less than 10% by weight; hot forging the copper billet at a temperature greater than 300°C to reduce the height by at least about 40%, thereby forming a forged block; Carry out the extrusion process, including: passing the forging block at least 4 passes through equal channel angular extrusion (ECAE); and heat treatment comprising heating the ECAE die one or two times during the extrusion process and performing an intermediate anneal at about 120°C to about 325°C for a period of at least 1 hour between at least some of the at least 4 passes; After the extrusion process, cold rolling to a reduction of less than about 90% to form a semi-finished product; and This semi-finished product is shaped into a target. 95. The method of claim 94, wherein the extrusion process comprises heating the ECAE die to about 125 to about 325°C. 96. The method of claim 94, further comprising solutionizing the forge prior to the extrusion process by heating to at least about 500°C and maintaining the temperature for at least about 60 minutes. 97. The method of claim 94, wherein the at least 4 passes consist of 4-6 passes. 98. The method of claim 94, wherein the method employs only temperatures less than or equal to 350°C during and after the extrusion process, and wherein forming the blank into the target comprises forming a monolithic target. 99. The method of claim 94, wherein forming the semi-finished product into a target comprises forming a bonded target. 100. The method of claim 99, further comprising performing a complete static recrystallization treatment at a temperature of about 250 to about 500°C for about 1 to about 8 hours prior to forming the attachment target. 101. The method of claim 99, further comprising performing a complete static recrystallization treatment at a temperature of about 250 to about 500°C for about 1 to about 8 hours after forming the attachment target. 102. The method of claim 99, wherein forming a bonded target comprises bonding the target to a support plate at a temperature of less than or equal to about 500° C. for less than or equal to about 4 hours, the bonding comprising isostatic pressing, rolling At least one of cladding, welding, explosive bonding, frictionless forging and diffusion bonding. 103. The method of claim 99, wherein the joining comprises diffusion joining to form a joint having a yield strength of at least about 10 to about 15 ksi. 104. The method of claim 94, wherein the average particle size is from 1 to about 20 microns. 105. The method of claim 104, wherein the average particle size is from about 5 to about 10 microns. 106. The method of claim 94, wherein the average particle size is less than 1 micron. 107. The method of claim 94, wherein there is a uniform particle size distribution throughout the bulk of the intermediate product, the uniform particle size having a standard deviation of less than 15% (1-[sigma]). 108. The method of claim 107, wherein the particle size uniformity standard deviation is less than about 10% (1-σ). 109. The method of claim 94, further comprising, prior to the extrusion process, aging at a temperature of less than about 500°C to form precipitates having an average precipitate size of less than or equal to about 0.5 microns.

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