WO2005077677A1 - Physical vapor deposition components, and methods of treating components - Google Patents

Abstract

The invention includes methods for removing embedded beab-blast media from physical vapor deposition components (14). The components comprise a material within which the bead-blast media is embedded. The components are subjected to an etch which removes some of the material, and thus loosens the embedded bead-blast media. The components (14) are subsequently exposed to a treatment which sweeps the loosened bead-blast media from the components (14). The invention also encompasses utilization of electroplated materials (170) as particle traps on PVD components (14). The electroplated materials (170) are plated under sufficiently high current density to form the electroplated materials (170) to have roughened outer surfaces.

Description

PHYSICAL VAPOR DEPOSITION COMPONENTS, AND METHODS OF TREATING COMPONENTS

RELATED PATENT DATA [0001] This application claims priority to U.S. Provisional Application Serial No.

60/543,355, which was filed February 9, 2004.

TECHNICAL FIELD [0002] The invention pertains to methods of treating deposition components, such as physical vapor deposition (PVD) process components; and pertains to the components themselves.

BACKGROUND OF THE INVENTION [0003] PVD methods are utilized for forming films of material across substrate surfaces. PVD methods can be utilized in, for example, semiconductor fabrication processes to form layers ultimately utilized in fabrication of integrated circuitry structures and devices. [0004] A PVD operation is described with reference to a sputtering apparatus

110 in Fig. 1. - Apparatus 1 10 is an example of an ion metal plasma (IMP) apparatus, and comprises a chamber 112 having sidewalls 1 14. Chamber 112 is typically a high vacuum chamber. A target 10 is provided in an upper region of the chamber, and a substrate 1 18 is provided in a lower region of the chamber. Substrate 118 is retained on a holder 120, which typically comprises an electrostatic chuck. Target 10 would be retained with suitable supporting members (not shown), which can include a power source. An upper shield (not shown) can be provided to shield edges of the target 10. Target 10 can comprise, for example, one or more of cobalt, indium, tin, nickel, tantalum, titanium, copper, aluminum, silver, gold, niobium, platinum, palladium, tungsten and ruthenium, including one or more alloys of the various metals. The target can be a monolithic target, or can be part of a target/backing plate assembly. [0005] Substrate 118 can comprise, for example, a semiconductor wafer, such as, for example, a single crystal silicon wafer. [0006] Material is sputtered from a surface of target 10 (specifically, is sputtered from a so-called sputtering face of the target), and is directed toward substrate 118. The sputtered material is represented by arrows 122.

[0007] Generally, the sputtered material will leave the target surface in a number of different directions. This can be problematic, and it is preferred that the sputtered material be directed relatively orthogonally to an upper surface of substrate 118. Accordingly, a focusing coil 126 is provided within chamber 112. The focusing coil can improve the orientation of sputtered materials 122, and is shown directing the sputtering materials relatively orthogonally to the upper surface of substrate 118. [0008] Coil 126 is retained within chamber 112 by pins 128 which are shown extending through sidewalls of the coil and also through sidewalls 114 of chamber 112. Pins 128 are retained with retaining screws in the shown configuration. The schematic illustration of Fig. 1 shows heads 132 of the pins along an interior surface of coil 126, and shows heads 130 of the retaining screws along the exterior surface of chamber sidewalls 114. [0009] Spacers 140 (which are frequently referred to as cups) extend around pins 128, and are utilized to space coil 126 from sidewalls 1 14. [0010] Problems can occur in deposition processes if particles are formed, in that the particles can fall into a deposited film and disrupt desired properties of the film. Accordingly, it is desired to develop traps which can alleviate problems associated with particles falling into a desired material during deposition processes. [001 1] Some efforts have been made to modify PVD targets to alleviate particle formation. For instance, bead blasting has been utilized to form a textured surface along sidewalls of a target with the expectation that the textured surface will trap particles formed along the surface. Also, knurling and machine scrolling have been utilized to form textures on target surfaces in an effort to create appropriate textures that will trap particles. [0012] Although some of the textured surfaces have been found to reduce particle formation, problems exist with various of the textured surfaces. For instance, bead-blasting typically utilizes media blasted at the target with high energy to texture a surface of the target. Some of the media from the blasting can be embedded in the target material during the blasting process, and remain within the target material as it is inserted in a PVD chamber. The surface of the media can have relatively poor adhesion for re-deposited material entering a particle trapping region, and can thus degrade performance of the particle-trapping region.

[0013] It would be desirable to develop new methodologies to reduce, and preferably eliminate, embedded bead-blasted media from particle trapping regions. It would be desirable for the new methodologies to be applicable for utilization with particle trapping regions associated with non-sputtered surfaces of numerous components within a chamber that may be exposed to sputtered material, including, but not limited to, surfaces of one or more of internal sidewalls of a chamber, coils, cover rings, clamps, shields, pins, cups, etc.; in addition to, or alternatively to, the utilization of the new methodologies on particle trapping regions formed on non-sputtered surfaces of PVD targets.

SUMMARY OF THE INVENTION [0014] In one aspect, the invention encompasses a cleaning process to remove embedded bead-blasted media from a target surface. The cleaning process utilizes an etchant selective for the target material to loosen the bead-blasted media from the target material. After utilization of the etchant, a stream of cleaning material, such as, for example, carbon dioxide, can be used to sweep the bead-blasted media from the target surface. [0015] In one aspect, the invention encompasses utilization of an electrically deposited film additionally to, or alternatively to, bead-blasting to form a particle trap. Material is electroplated onto surfaces of sputtering components where particle traps are desired, and the electroplating is conducted at sufficiently high current densities to form a rough surface of electroplated material. In particular aspects, the electroplated material can comprise, consist essentially of, or consist of copper.

BRIEF DESCRIPTION OF THE DRAWINGS [0016] Preferred embodiments of the invention are described below with reference to the following accompanying drawings. [0017] Fig. 1 is a diagrammatic, cross-sectional view of a prior art physical vapor deposition apparatus shown during a physical vapor deposition (e.g., sputtering) process. [0018] Fig. 2 is a diagrammatic, top view of an exemplary target construction suitable for utilization in methodology of the present invention.

[0019] Fig. 3 is a diagrammatic, cross-sectional view along the line 3-3 of Fig. 2.

[0020] Fig. 4 is a view of an expanded region of the Fig. 3 target construction

(the region labeled 4 in Fig. 3).

[0021] Fig. 5 is a view of the Fig. 4 expanded region shown at a processing stage subsequent to that of Fig. 4 in accordance with a first embodiment aspect of the present invention.

[0022] Fig. 6 is a view of an expanded region of the Fig. 5 target construction

(the region labeled 6 in Fig. 5), and shown at the processing stage of Fig. 5. [0023] Fig. 7 is a view of the Fig. 6 expanded region shown at a processing stage subsequent to that of Fig. 6 in accordance with the first embodiment aspect of the invention. [0024] Fig. 8 is a view of the Fig. 6 expanded region shown at a processing stage subsequent to that of Fig. 7 in accordance with the first embodiment aspect of the invention. [0025] Fig. 9 is a view of the Fig. 4 expanded region shown at a processing stage subsequent to that of Fig. 4 in accordance with a second embodiment aspect of the invention. [0026] Fig. 10 is a view of the Fig. 4 expanded region shown at a processing stage subsequent to that of Fig. 4 in accordance with a third embodiment aspect of the invention. [0027] Fig. 11 is a view of the Fig. 4 expanded region shown at a processing stage subsequent to that of Fig. 10 in accordance with the third embodiment aspect of the invention. [0028] Fig. 12 is an expanded view of a portion of the Fig. 11 structure. [0029] Fig. 13 is a view of the Fig. 4 expanded region shown at a processing stage subsequent to that of Fig. 11 in accordance with the third embodiment aspect of the invention. [0030] Fig. 14 is an expanded view of a portion of the Fig. 13 structure. [0031] Fig. 15 is a view of the Fig. 4 expanded region shown at a processing stage subsequent to that of Fig. 11 in accordance with a fourth embodiment aspect of the invention. [0032] Fig. 16 is a diagrammatic, top view of an exemplary target/backing plate construction suitable for utilization in methodology of the present invention.

[0033] Fig. 17 is a diagrammatic, cross-sectional view along the line 17-17 of

Fig. 16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0034] The invention encompasses methods of texturing surfaces of PVD components. The textures can be utilized for trapping materials which deposit on the components during deposition processes. In some aspects, machine tool treatments (e.g., sawing, knurling, etc.) are utilized to form projections (such as, for example, a bent scroll pattern) on one or more surfaces of a PVD component to form particle trapping areas. If the treated component is a sputtering target, the treated surfaces can include any non-sputtered surfaces, such as, for example, side all surfaces, flange surfaces and/or non-sputtered surfaces along a sputtering face. The projections formed on the component can have roughened surfaces formed thereon by one or both of bead- blasting and electroplating to improve trapping properties of the projections. The projections can be considered to form a macroscale roughness of a trapping area (i.e., to form macrostructures) and the roughened surfaces of the projections can be considered to form a microscale roughness of the trapping area (i.e., to form microstructures). Thus, the invention can include patterns which have one or both of macroscale and microscale roughness, and which are utilized in trapping areas.

[0035] The utilization of both macroscale and microscale patterns can be advantageous. The combined macroscale pattern and microscale pattern can significantly reduce material fall-off from a treated surface of a component during a deposition process. Also, the formation of a microscale roughened surface on the macroscale pattern can effectively reduce problems that may otherwise be associated with cyclic thermal stresses occurring during cyclic deposition processes. Specifically, a macroscale pattern alone (such as, for example, a long machined scroll) can trap redeposited materials to form a long film within a trapping region. Cyclic thermal stresses (such as stress associated with, for example, a different thermal expansion coefficient of the redeposited film versus the base material of the treated component), can lead to peeling of the film or to peeling of clusters of redeposited film from the treated component. As film or clusters peel from the component, they can fall onto a substrate and create undesired defects.

[0036] Although it can be advantageous to impart both macroscale and microscale roughness to a surface, there can also be aspects in which microscale roughness alone is desired for trapping. Accordingly, the invention also includes aspects in which microscale roughness is formed on one or more surfaces of a sputtering component without macroscale roughness. Alternatively, it may be desirable to have macroscale roughness alone, and accordingly the invention also includes aspects in which macroscale roughness is formed on one or more surfaces of a sputtering component without microscale roughness.

[0037] An exemplary first aspect of the invention is described with reference to

Figs. 2-8 for treating a component of PVD process (specifically for treating non- sputtered surfaces of a sputtering target).

[0038] Referring to Figs. 2 and 3, an exemplary sputtering target construction 10 is illustrated in top view (Fig. 2) and cross-sectional side view (Fig. 3). Construction 10 is shown as a monolithic physical vapor deposition target in the exemplary aspect of the invention, but it is to be understood that construction 10 can alternatively be a target/backing plate construction (exemplary target/backing plate constructions are shown in Figs. 16 and 17). Target construction 10 comprises a sputtering face 12 and sidewalls 14 proximate the sputtering face. Construction 1 0 also comprises a flange 16 extending around a lower region of the target construction. Construction 10 is shown as a VECTRA-IMP™-type target, such as is available from Honeywell International Inc., but it is to be understood that other target constructions can be utilized in various aspects of the present invention. [0039] Sputtering face 12 can have both a region from which materials are sputtered in a PVD operation and a region from which materials are not sputtered in the PVD operation. The non-sputtering region can encompass, for example, a region proximate sidewall 14 corresponding to a laterally peripheral region of face 12. [0040] As discuss above, a problem with utilizing target construction 10, or other target configurations, in sputtering operations is that some materials sputtered from face 12 can redeposit on other surfaces of the target construction (such as non-sputtered regions including the sidewalls 14, flange 16 and non-sputtered regions of face 12). The redeposited material can ultimately fall from the target construction as particles during a PVD operation. The particles can deposit within a layer sputter-deposited during the PVD operation to detrimentally affect properties of the layer, and/or can fall onto an electrostatic chuck provided to support a substrate. It is therefore desired to develop methods for treating the sidewalls, flanges and/or other non-sputtered surfaces of the target to avoid particle contamination of a sputter-deposited layer. [0041] In accordance with an aspect of the present invention, surfaces of face

12 (the non-sputtered surfaces), sidewall 14 and/or flange 16 are treated by new methodologies to alleviate particle formation. The treated regions can, for example, extend partially or entirely across the regions indicated by brackets 18 in Fig. 3. It can be particularly preferred to utilize methodology of the present invention to treat all non- sputtered surfaces of a target (whether on the face 12, sidewall 14 or flange 16) that are exposed to a vacuum within a PVD reaction chamber. [0042] Fig. 4 shows an expanded region 20 of sidewall 14 at a preliminary processing stage for exemplary methods of the present invention. The sidewall has a relatively planar surface 21.

[0043] Fig. 5 illustrates expanded region 20 at a processing stage subsequent to that of Fig. 4 in accordance with an exemplary first embodiment aspect of the present invention. Surface 21 has been treated with particle-blasting methodology (typically referred to as bead-blasting methodology) to roughen the surface. The particles utilized during the bead-blasting can be particles of any suitable composition, including, for example, particles comprising, consisting essentially of, or consisting of silicon carbide, aluminum oxide, or garnet, and accordingly can comprise various ceramic materials. (Garnet is typically understood to be a material having the composition X₃Y₂Si₃O₁₂, where X is selected from the group consisting of Fe²⁺, Mg, Mn and Ca; and where Y is selected from the group consisting of Al, Fe³⁺ and Cr.) Generally, the surface 21 will comprise a first composition, and the particles will comprise a second composition which is different from the first composition. [0044] As discussed above in the "Background" section of this disclosure, a problem with bead-blasting methodologies is that some of the beads can become embedded in a treated surface. Fig. 6 shows an expanded view of a portion of surface 21 at the processing stage of Fig. 5, and shows beads 100 embedded into the roughened surface of target material 14. [0045] Conventional methodologies utilize various cleaning procedures to attempt to remove the beads from surface 21. The procedures can include, for example, flowing streams of gas and/or liquid against surface 21 in an effort to dislodge the beads 100 from the surface. However, the embedded beads can be too tightly retained within material 14 to be dislodged by conventional methodologies. The beads will thus remain embedded within the surface after the conventional cleaning. The beads can subsequently adversely affect the performance of a particle trapping region, in that the surfaces of the beads will poorly retain materials re-deposited in the particle trapping region. This problem can manifest itself in any sputtering process, but can be particularly problematic during titanium and titanium nitride deposition processes. [0046] As device geometries associated with semiconductor structures shrink to

0.25 microns and below, the specification limits for particles per wafer become increasingly more stringent. The loss of yield due to release of "ball type" particles (which can include particles released from non-sputtered regions of PVD components) is measurable, and unacceptable. The level of loss becomes particularly problematic as device geometries shrink to the domain of from about 0.18 microns to about 0.15 microns, and below.

[0047] A typical particle size for release from surfaces of non-sputtered regions of a PVD component (such as the region 18 of the target of Fig. 3) can be about 0.2 microns, and yield loss due to these particles can be as high as 15%. It is believed that particles of the size of about 0.2 microns result from flakes of titanium and titanium nitride that are deposited on non-sputtered regions of PVD components (such as the target flange area and surfaces of shielding) during a PVD process, with such flakes subsequently being released as particles. [0048] The roughening process of Fig. 5 can produce a roughened surface area which improves adhesion of titanium and titanium nitride re-deposited layers. The adhesion of the re-deposited layers can retain the layers, and can thus avoid release of particles corresponding to the re-deposited layers. However, the entrapped bead-blast media (such as, for example, particles 100 of Fig. 6) can degrade the adhesion capability of the re-deposited titanium and titanium nitride layers on a treated surface. Particles of titanium and titanium nitride deposited on the media particles 1O0 can fall off of the particle trapping region, and thus the effectiveness of the particle trapping region is degraded due to the embedded particles 100. [0049] An aspect of the present invention encompasses methodology which improves removal of embedded bead-blast material. Initially, media size, nozzle pressure, media stream angle, turntable rotation speed, and other parameters associated with a bead-blasting process can be controlled to reduce, and preferably minimize, the amount of trapped media associated with a roughened surface. Subsequently, surface 21 is treated with a chemical etch which removes some of component material 14 to loosen the embedded particles 100 from material 14. Such etch can be referred to as being selective for the component material 14 relative to the particle material. The term "selective" indicates that the etch removes component material 14 at a faster rate than material of particles 100, which includes, but is not limited to, etches which remove only material 14, (i.e., etches 100% selective for material 14 relative to the material of the particles). [0050] Fig. 7 shows the expanded region of Fig. 6 after treatment with a chemical etchant. The treatment has removed some of the material 14 associated with surface 21 , and has thus formed cavities 102 around the embedded particles 100. The etchant utilized for removing material 14 can be any suitable etchant known to remove the composition of material 14. For instance, if material 14 comprises titanium, various etchants are known in the art which can remove some of the titanium-containing material, including, for example, utilization of a solution comprising 20-25% nitric acid; 3- 5% hydrofluoric acid and the balance water of a time of about 5-10 seconds, with agitation. An identical solution can be utilized for etching metallic aluminum, with the time being increased to 20-30 seconds. [0051 ] After the etchant has formed cavities 102, surface 21 is treated by exposure to appropriate conditions to remove the particles 100 from the surface. Such conditions can comprise, for example, exposing surface 21 to a stream of liquid and/or gas, with an exemplary stream being a high pressure stream of carbon dioxide gas. [0052] Fig. 8 shows the expanded region of Fig. 7 after treatment with the appropriate conditions to remove the beads 100 (Fig. 7). [0053] Referring next to Fig. 9, such shows the expanded region 20 of Fig. 4 at a processing stage subsequent to Fig. 4 in accordance with an exemplary second aspect of the invention. A material 160 is formed over surface 21 , with material 160 having a roughened surface 161. Material 160 is electroplated onto surface 21. Current density, current modulation and deposition thickness are regulated to form the desired surface roughness of roughened surface 161. Material 160 can, in particular aspects, comprise, consist essentially of, or consist of copper. The composition of material 160 can approximately match that of material 14. Accordingly, it can be advantageous to utilize relatively pure copper for material 160 in applications in which material 14 is a high purity copper material. Alternatively, material 160 can differ from material 1 4, provided that the material 160 is compatible with material 14 for a particular sputter deposition process. The electrodeposition aspects of the invention can be utilized with any suitable target, and in particular aspects will be utilized with targets comprising, consisting essentially of, or consisting of one or more of cobalt, silver, nickel, copper, indium, tin, gold and platinum. [0054] The electroplated material 160 can be considered a roughened coating formed over the surface 21 , and in particular aspects such coating can have a thickness of from about 25 microns to about 200 microns, with an exemplary thickness being from about 75 microns to about 150 microns.

[0055] The current density, current modulation and deposition thickness utilized to form material 160 can vary depending upon the roughness and texture desired, and the composition of material 160. The plating of material 160 can, in some aspects, be considered to provide a random pattern that can be superimposed on larger macro- features. However, while electrochemical plating is primarily a micro-feature enhancement, it can also be utilized under appropriate conditions to yield roughness values in the lower range of macro-features.

[0056] Although the electroplating aspect of Fig. 9 can be utilized in conjunction with numerous sputtering components having various compositions, and numerous compositions for layer 160, the methodology can be particularly advantageous for utilization in plating high-purity copper materials over copper-containing sputtering target constructions. The sputtering target constructions can be monolithic copper-containing targets, or can be target/backing plate constructions in which the target comprises high purity copper, and the backing plate comprises a copper-containing composition, (including, for example, CuCrNiSi or CuCrZn, with the compositions being shown in terms of the elements contained therein, rather than in terms of any particular stoichiometry of the elements). [0057] An advantage of utilizing roughened copper layers for particle traps can be that the copper can provide superior adhesion to retain particles relative to other compositions. [0058] Exemplary roughnesses that can be achieved for copper-containing materials utilizing electrodeposition methodologies are roughnesses in excess of 150 micro-inches, or even in excess of 250 micro-inches. The texture of the deposit may be regulated via the manipulation of different plating parameters, including, for example, plating cycle, solution temperature and deposit thickness. For instance, it is found that plating temperatures in excess of 100°F can increase roughness when plating Cu onto Ti (with the Cu coming from a Cu sulfate solution), and that temperatures of at least about 120°F can be preferred. As another example, it is found that roughness generally increases with increasing the thickness of a plated deposit. [0059] Exemplary processing conditions can include: cycle times of 40-90 minutes; plating solution temperatures of about 120°F or above (in some aspects, 128°F and above); current of a forward cycle of at least about 16 amps (in some aspects, of at least about 30 amps); current of a reverse cycle of from about 4 amps to about 8 amps; voltage of at least about 2.5 volts (in some aspects of at least about 5 volts); forward cycles of 0.01 seconds to 0.05 seconds; and reverse cycles of 0.01 seconds to 0.05 seconds. [0060] It is noted that gasses can provide problems during electroplating, and accordingly that relatively aggressive solution mixing can be desired during the plating operations.

[0061] Fig. 10 illustrates expanded region 20 in accordance with an exemplary third aspect of the invention, and after sidewall 14 has been treated to form a pattern of projections 22 extending across a surface of the sidewall. Projections 22 can be formed utilizing a computer numerically controlled (CNC) tool, knurling device or other suitable machine tool, and can correspond to a scroll pattern. For example, a CNC tool can be utilized to cut into sidewall 14 and leave the shown pattern and/or a knurling device can be utilized to press into sidewall 14 and leave the pattern. The pattern is a repeating pattern, as opposed to a random pattern that would be formed by, for example, bead- blasting. The pattern of projections 22 can be referred to as a macropattern, to distinguish the pattern from a micropattern that can be subsequently formed (discussed below). The projections 22 can be formed to a density of from about 28 per inch to about 80 per inch, with about 40 per inch being typical. In particular applications the projections can be formed with a tool having from about 28 teeth per inch (TPI) to about 80 TPI, with about 40 TPI being typical. The teeth of the tool can be in a one-to-one correspondence with the projections 22. The projections 22 can be formed across a surface of flange 16 (Fig. 3) and/or non-sputtered regions of face 12 alternatively, or additionally, to formation of the projections along the sidewall surface 14. [0062] Fig. 11 shows expanded region 20 after the projections 22 have been subjected to a mechanical force which bends the projections over. The mechanical force can be provided by any suitable tool, including, for example, a ball or roller. The bent projections can also be formed utilizing suitable directional machining with a CNC tool. The bent projections define cavities 23 between the projections, and such cavities can function as traps for redeposited material and/or other sources of particles. [0063] Referring again to Fig. 3, sidewall 14 can be considered to be proximate sputtering face 12, and to form a lateral periphery of target construction 10 around the sputtering face. The bent projections 22 (which can also be referred to as curved projections) of Fig. 11 can thus be understood to form cavities 23 which open laterally along the sidewall. The cavities 23 can alternatively be considered a repeating pattern of receptacles formed by the bent, or curved, projections 22. The receptacles 23 can ultimately be utilized for retaining redeposited materials, or other materials that could be one of the sources of particles during a PVD process. The receptacles 23 have inner surfaces 27 around an interior periphery of the receptacles. [0064] If the sputtering surface 12 (Fig. 3) is defined as an upper surface of target construction 10 (i.e., if the target construction is considered in the orientation of Fig. 3), the shown cavities open downwardly. In other aspects of the invention (not shown) the curved projections can form cavities which open upwardly in the orientation of Fig. 3, or sidewardly. Accordingly, the invention encompasses aspects in which a sputtering face is defined as an upper surface of a target construction, and in which curved projections are formed along a sidewall of the target construction to form cavities which open laterally along the sidewall in one or more of a downward, upward and sideward orientation relative to the defined upper surface of the sputtering face. It is noted that the sputtering face is defined as an upper surface for purposes of explaining a relative orientation of the cavities formed by the curved projections, rather than as indicating any particular orientation of the target construction relative to an outside frame of reference. Accordingly, the sputtering surface 12 (Fig. 3) may appear as an upward surface of the target construction, downward surface of the target construction, or side surface of the target construction to a viewer external to the target construction; but for purposes of interpreting this disclosure, the surface can be considered a defined upper surface to understand the relationship of the sputtering surface to the directionality of the openings of the cavities 23 formed by curved projections 22. [0065] It can be advantageous that the cavities 23 open upwardly in the orientation in which target construction 10 is ultimately to be utilized in a sputtering chamber (such as, for example, the chamber 112 of Fig. 1 ). Accordingly, it can be advantageous that the cavities open in the shown downward configuration relative to a sputtering surface 12 defined as an upper surface of the target construction. [0066] Fig. 12 illustrates an expanded region 30 of the Fig. 11 structure, and specifically illustrates a single projection 22. [0067] The curved projections 22 of Figs. 11 and 12 can have a height "H" above surface 14 of, for example, from about 0.0001 inch to about 0.1 inch (typically about 0.01 inch), and a repeat distance ("R") of from about 0.001 inch to about 1 inch (typically about 0.027 inch). The distance "R" can be considered to be a periodic repeat distance of the curved projections 22. [0068] In particular aspects, curved projections 22 can be considered to have bases 25 where the curved projections join to sidewall 14, and sidewall 14 can be considered to have a surface 15 extending between the bases of the curved projections. The curved projections will typically have a maximum height above the sidewall surface 15 of from about 0.0001 inches to about 0.01 inches.

[0069] Figs. 13 and 14 show the projections 22 after they have been treated to form microstructures 32 extending along the projections as cavities or divots. The treatment preferably extends into the receptacles 23 to roughen the inner surfaces 27 (as shown). The microstructures together define a microstructural roughness. [0070] The treatment of projections 22 can utilize, for example, one or both of a chemical etchant and mechanical roughening. Exemplary mechanical roughening procedures include exposure to a pressurized stream of particles (e.g., bead-blasting), or exposure to rigid bristles (such as wire bristles). Exemplary chemical etchants include solutions which chemically pit the material of projections 22, and can include strongly basic solutions, weakly basic solutions, strongly acidic solutions, weakly acidic solutions, and neutral solutions. [0071 ] If bead blasting is utilized to form microstructures 32, the particles used to form the microstructures can comprise, for example, one or more of garnet, silicon carbide, aluminum oxide, solid H₂O (ice), solid carbon dioxide, and salt (such as, for example, a salt of bicarbonate, such as sodium bicarbonate). Additionally or alternatively, the particles can comprise one or more materials at least as hard as the material in which the microstructures are to be formed. [0072] If the particles utilized for the bead-blasting comprise a non-volatile material, a cleaning step can be introduced after formation of divots 32 to remove the particles. For instance, if the particles comprise silicon carbide or aluminum oxide, a cleaning step can be utilized wherein projections 22 are exposed to a bath or stream of cleaning material and/or are brushed with an appropriate brushing tool (such as a wire brush). A suitable stream can be a stream comprising solid H₂O or solid carbon dioxide particles. Additionally, the processing of Figs. 5-8 can be utilized to etch material 14 so that embedded particles can be more readily dislodged from material 14. If the particles initially utilized to form divots 32 consist essentially of, or consist of, volatile particles (such as solid ice or solid CO₂), then the cleaning step described above can be omitted. [0073] In a particular aspect, the bead-blasting media can be 24 grit AI2O3 media, and the bead-blasting can be conducted to, for example, from about 1 to about 4000 micro-inch RA, preferably from about 50 to about 2000 micro-inch RA, and typically from about 100 to about 300 micro-inch RA. [0074] The sidewall 14 shown at the processing stage of Figs. 13 and 14 can be considered to have a surface comprising a trapping area with both macroscale and microscale structures therein. Specifically, projections 22 can have a length of 0.01 inches, and can be considered to be a macroscale feature formed on a substrate. The divots formed within the projections can be considered to be microscale structures formed along surfaces of projections 22. The combination of the microscale and macroscale structures can alleviate, and even prevent, the problems described previously in this disclosure regarding undesired incorporation of particles into sputter- deposited layers. The microscale structures formed across the macroscale structures can, in some aspects, also advantageously alleviate, and in some cases entirely prevent, arcing that could otherwise occur in a PVD process. [0075] Although the exemplary aspect of the invention described herein forms the microstructures on projections 22 after bending the projections, it is to be understood that the invention encompasses other aspects (not shown) in which the microstructures are formed prior to bending the projections. Specifically, projections 22 can be subjected to bead-blasting and/or chemical etching at the processing stage of Fig. 10, and subsequently bent, rather than being bent and subsequently subjected to bead-blasting and/or chemical etching.

[0076] The projections 22 of Figs. 10-14 can be formed along some or all of the region 18 of Fig. 3. Accordingly, the projections can extend at least partially along sidewall 14 and/or at least partially along flange 16 and/or along non-sputtered laterally peripheral regions of face 12. In particular aspects, the projections will extend entirely along sidewall surface 14, and/or will extend entirely along flange 16 and/or will extend entirely along non-sputtered laterally peripheral regions of face 12. [0077] Referring next to Fig. 15, such shows construction 20 at a processing stage subsequent to that of Fig. 1 1 in accordance with a fourth aspect of the invention. An electrodeposited material 1 0 is formed over projections 22, with such electrodeposited material having a roughened surface 171. Electrodeposited material 170 can comprise the same compositions as discussed above regarding electrodeposited material 160 of Fig. 9. Accordingly, the construction of Fig. 15 can be understood to be a combination of the aspect of Fig. 9 with that of Fig. 11. Although electrodeposited material 170 is shown formed after projections 22 are bent, it is to be understood that the electrodeposited material could alternatively be formed before the projections are bent (i.e., after the processing stage of Fig. 10 and before that of Fig. 11 ). The projections could then be bent after formation of the electrodeposited material, or can be left in unbent form in the final particle traps. Further, electrodeposition could occur in combination with bead-blasting; either the bead-blasting described with reference to Fig. 5, (i.e., without mechanical formation of projections on the surface), the bead-blasting of Fig. 13, or a bead-blasting step occurring on the non-bent projections of Fig. 10 in processing which is not shown.

[0078] To the extent that electrodeposition and bead-blasting are both utilized to form particle traps, it can be advantageous that the bead-blasting occur before the electrodeposition, in that bead-blasting is a relatively coarse procedure (i.e., forms bigger structures) as compared to the electrodeposition. Further, to the extent that tooled projections are formed in conjunction with bead-blasting, it can be advantageous that the tooled projections be formed prior to the bead-blasting, in that the machine tooling tends to produce relatively coarse features compared to structures formed by bead-blasting. To the extent that electrodeposition is utilized in conjunction with both bead-blasting and machine tooling for formation of projections, it can be advantageous if the machine tooling occurs first, the bead-blasting occurs second, and the electrodeposition occurs last. However, it is to be understood that the invention also encompasses aspects in which the processing occurs in other sequences besides the preferred sequences described above. [0079] The embodiments of Figs. 9 and 15 can be considered to correspond to targets having body regions (14) and roughened electroplated material (160 or 170) covering portions of the body regions. In some aspects, the body region and electroplated material will have about the same composition as one another, and in other aspects the body region and electroplated material will have different compositions from one another. In aspects in which the body region and electroplated material have different compositions, they can primarily comprise different elements, or primarily comprise the same element. For instance, the body region and electroplated material may both primarily comprise copper, but due to a difference in the purity of the copper in the body region relative to the electroplated region, the two regions have different compositions relative to one another. In a particular aspect of the invention, the body region will comprise, consist essentially of, or consist of titanium; and the electroplated material will comprise, consist essentially of, or consist of copper. [0080] Figs. 2 and 3 illustrate a monolithic target construction. Persons of ordinary skill in the art will recognize that sputtering target constructions can also comprise target/backing plate constructions. Specifically, a sputtering target can be bonded to a backing plate prior to provision of the target in a sputtering chamber (such as the chamber described with reference to Fig. 1). The target/backing plate construction can have any desired shape, including the shape of the monolithic target of Figs. 2 and 3. The backing plate can be formed of a material cheaper than the target, more easy to fabricate than the target, or having other desired properties not possessed by the target. The backing plate is utilized to retain the target in the sputtering chamber. The invention can be utilized to treat target/backing plate constructions in a manner analogous to that described in Figs. 2-9 for treating a monolithic target construction. [0081] Figs. 16 and 17 illustrate an exemplary target/backing plate construction

(or assembly) 200 which can be treated in accordance with methodology of the present invention. In referring to Figs. 16 and 17 similar number will be utilized as was used above in describing Figs. 2-4, where appropriate. [0082] Construction 200 comprises a target 202 bonded to a backing plate 204.

The target and backing plate join at an interface 206 in the shown assembly. The bond between target 202 and backing plate 204 can be any suitable bond, including, for example, a solder bond or a diffusion bond. Target 202 can comprise any desired material, including metals, ceramics, etc. In particular aspects, the target can comprise one of more of the materials described previously relative to the target 10 of Figs. 2 and 3. Backing plate 204 can comprise any appropriate material or combination of materials, and frequently will comprise one or more metals, such as, for example, one or more of Al, Cu and Ti. [0083] Construction 200 has a similar shape to the target construction 10 of Figs

2 and 3. Accordingly, construction 200 has a sputtering face 12, a sidewall 14 and a flange 16. Any of various non-sputtered surfaces of construction 200 can be treated with methodology of the present invention similarly to the treatment described above with reference to Figs. 2-15. Accordingly, all or part of a shown region 18 of construction 200 can be treated. [0084] A difference between construction 200 of Fig. 17 and construction 10 of

Fig. 3 is that sidewall 14 of the Fig. 17 construction includes both a sidewall of a backing plate (204) and a sidewall of a target (202), whereas the sidewall 14 of the Fig. 3 construction included only a target sidewall. The treated region 18 of the Fig. 17 construction can thus include particle traps formed along a sidewall of backing plate 204 and/or particle traps formed along a sidewall of target 202. Additionally or alternatively, the treated region can comprise particle traps formed along flange 16 and/or can include particle traps formed along a non-sputtered portion of face 12. The particle traps can be formed with methodology identical to that described with reference to one or more of the aspects of Figs. 4-15. [0085] The target 202 of construction 200 can be treated to form particle traps along sidewall regions and/or non-sputtered regions of the sputtering face before or after the target is bonded to the backing plate. Similarly, the backing plate 204 of the construction can be treated to form particle traps along sidewall regions and/or flange regions before or after the backing plate is bonded to the target. Typically, both the target and the backing plate will have one or more surfaces treated to form particle traps, and the treatment of the target and/or backing plate of construction 200 will occur after bonding the target to the backing plate so that the target and backing plate can be concurrently treated.

[0086] The methodology described above for treating non-sputtered regions of a sputtering target can be utilized for treating surfaces of numerous components suitable for utilization in numerous deposition processes, and can be utilized while maintaining desired roughness controls. For instance, the methodology can be utilized for treating surfaces of cups, pins, shields, coils, cover rings, clamps, chamber internal sidewalls, etc. for PVD processes.

Claims

CLAIMS The invention claimed is:

1. A particle-blasting method for roughening a surface of a component, comprising: providing a component that is ultimately to be utilized in a PVD chamber, the component comprising a first composition; roughening a surface of the component by blasting the surface with particles, the particles comprising a second composition which is different from the first composition, some of the particles becoming embedded in the surface during the roughening; utilizing an etchant selective for the first composition relative to the second composition to loosen the embedded particles from the surface; and removing the loosened particles from the surface.

2. The method of claim 1 wherein the removal of the loosened particles utilizes a stream of cleaning material to sweep the loosened particles from the surface.

3. The method of claim 1 wherein the particles comprise one or more of silicon carbide, aluminum oxide and garnet; and wherein the component comprises one or more of cobalt, indium, tin, nickel, tantalum, titanium, copper, aluminum, silver, gold, niobium, platinum, palladium, tungsten and ruthenium.

4. The method of claim 1 wherein the particles comprise one or more of silicon carbide, aluminum oxide and garnet; and wherein the component comprises titanium.

5. The method of claim 1 wherein the component is a sputtering target.

6. The method of claim 1 further comprising machine tooling a pattern of projections onto the surface prior to the roughening; and wherein: the machine tooling forms macrostructures and the roughening forms microstructures on the macrostructures; and the macrostructures and microstructures together form a trapping region for trapping materials during a sputtering process.

7. The method of claim 1 further comprising electroplating a roughened material onto the surface after the removal of the loosened particles.

8. The method of claim 7 wherein the particles comprise one or more of silicon carbide, aluminum oxide and garnet; wherein the component comprises titanium; and wherein the electroplated material comprises copper.

9. A method of forming a particle trap on a surface of a sputtering component, comprising: providing a sputtering component having a region where the particle trap is desired; and electroplating a material onto said region under conditions which form a rough surface of electroplated material, said rough surface having a surface roughness of at least about 150 micro-inches.

10. The method of claim 9 wherein the surface roughness is at least about 250 micro-inches.

11. The method of claim 9 further comprising: (1 ) machine tooling a pattern of projections onto the region, and (2) roughening the machine-tooled projections by particle-blasting; and wherein the electroplating of the material comprises electroplating the material onto the roughened projections.

12. The method of claim 11 further comprising bending the projections prior to the roughening.

13. The method of claim 11 wherein the sputtering component comprises a first composition, wherein the particle-blasting utilizes particles of a second composition different from the first composition; wherein some of the particles are embedded within the projections during the particle-blasting; and further comprising, prior to the electroplating: (1) utilizing an etch selective for the first composition relative to the second composition to loosen the embedded particles, and (2) removing the loosened particles.

14. The method of claim 9 wherein the component is a PVD target.

15. A PVD target comprising: a body formed of a first composition, the body having a sputtering surface and a sidewall laterally proximate the sputtering surface; and a coating along the sidewall and not along the sputtering surface, the coating being of a second composition different from the first composition, the coating having a surface roughness of at least about 150 micro-inches.

16. The target of claim 15 wherein the surface roughness is at least about 250 micro-inches.

17. The target of claim 15 wherein the first and second compositions comprise one or more of cobalt, indium, tin, nickel, tantalum, titanium, copper, aluminum, silver, gold, niobium, platinum, palladium, tungsten and ruthenium.

18. The target of claim 15 wherein the first composition comprises one or more of cobalt, indium, tin, nickel, tantalum, titanium, copper, aluminum, silver, gold, niobium, platinum, palladium, tungsten and ruthenium; and wherein the second composition comprises copper.

19. The target of claim 15 further comprising a plurality of curved projections along the sidewall, the projections forming cavities that open laterally along the sidewall; and wherein the coating extends along the projections and within the cavities, the coating within the cavities only partially filling the cavities.

20. A sputtering component, comprising: a body formed of a titanium-containing material; and a copper-containing coating on the body and having a surface roughness of at least about 150 micro-inches.

21. The component of claim 20 wherein the surface roughness is at least about 250 micro-inches.

22. The component of claim 20 being a sputtering target having a sputtering face and a sidewall laterally proximate the sputtering face, and wherein the copper- containing coating is along the sidewall and not along the sputtering face.

23. The component of claim 20 wherein the body consists essentially of titanium and the coating consists essentially of copper.

24. The target of claim 20 being a sputtering target having a sidewall, and comprising a plurality of curved projections along the sidewall, the projections forming cavities that open laterally along the sidewall; and wherein the coating extends along the projections and within the cavities, the coating within the cavities only partially filling the cavities.