JP2007517133A - Method of processing a deposition process component to form a particle trap and a deposition process component having a particle trap on a surface - Google Patents

Abstract

The present invention encompasses a method of forming a particle trap along the surface of a PVD (physical vapor deposition) component, including the PVD component having a particle trap on its surface. The present invention can include the use of highly soluble media for bead blasting and / or the use of metallic materials as bead blasting media. The present invention may also include forming an insert along the region of the backplate that is the desired location for the particle trap. The composition of this insert has better particle capture properties than the backing.

Description

  [0001] This application claims priority from US Provisional Patent Application No. 60 / 502,689 filed on September 11, 2003, and also filed US Patent Provisional Application No. 60 / 502,689 filed February 9, 2004. The priority of 60/543457 is asserted in the same way. [0002] The present invention relates to a method for forming a particle trap along a region of a physical vapor deposition (PVD) process component, such as a sputter target.

  [0003] PVD methods are used to form a thin film of material across the entire surface of a substrate. PVD methods can be used, for example, in semiconductor manufacturing methods to form layers that are ultimately used in the manufacture of integrated circuit structures and devices. [0004] The PVD operation will be described with reference to the sputtering apparatus 110 of FIG. Apparatus 110 is an example of an ion metal plasma (IMP) apparatus and includes a chamber 112 having a side wall 114. The chamber 112 is generally a high vacuum chamber. A target 10 is provided in the upper region of the chamber and a substrate 118 is provided in the lower region of the chamber. The substrate 118 is held on a holder 120 that typically includes an electrostatic chuck.

  The target 10 will be held by a suitable support member (not shown) that may include a power source. An upper shield (not shown) may be provided to shield the edge of the target 10. Targets 10 include, for example, indium, tin, nickel, tantalum, titanium, copper, aluminum, silver, gold, niobium, platinum, palladium, tungsten, and ruthenium, including one or more various types of metal alloys. One or more metals may be included. This target may be a monolithic target or may be part of a target / backplate assembly.

  [0005] The substrate 118 may include, for example, a semiconductor wafer (eg, a single crystal silicon wafer). [0006] Material is sputtered from the surface of the target 10 and directed toward the substrate 118. The sputtered material is represented by arrow 122. [0007] Generally, the sputtered material exits the target surface in several different directions. Although this can be a problem, it is preferred that the sputtered material be oriented relatively orthogonal to the upper surface of the substrate 118. Therefore, the focusing coil 126 is provided inside the small chamber 112. The focusing coil can correct the orientation of the sputtered material 122 and is shown with the sputtered material oriented relatively orthogonal to the upper surface of the substrate 118.

  [0008] The coil 126 is held inside the chamber 112 by a pin 128 that is shown passing through the side wall of the coil and also through the side wall 114 of the chamber 112. The pin 128 is held by a holding screw 132 in the illustrated configuration. The schematic diagram of FIG. 1 shows a pin head 130 along the inner surface of the coil 126 and another set of multiple heads 132 of retaining screws along the outer surface of the chamber sidewall 114. A spacer 140 (sometimes called a cup) extends around the pin 128 and is used to separate the coil 126 from the sidewall 114.

  [0010] The formation of particles can cause problems in the deposition process in that these particles can fall into the deposited thin film and interfere with the desired properties of the thin film. Therefore, it is desirable to develop traps that can ameliorate the problems associated with these particles falling into the desired material during the deposition process. [0011] Many efforts have been devoted to improving PVD targets to reduce particle formation. For example, bead blasting is used to form a textured surface along the target sidewall that is formed along the surface by the textured surface. Is expected to be captured. Also, knurling and machining swirl have been used to create a texture on the target surface in an attempt to create a suitable texture to capture the particles.

  [0012] Although some of these textured surfaces have been found to reduce particle formation, problems exist with various textured surfaces. For example, bead blasting typically uses particles that are strongly sprayed onto the target. Some of the particles from the blast can be embedded in the target material during the blasting process and remain in the target material when the target is inserted into the PVD chamber. The surface of the bead can be relatively poorly adhered to the redeposition material entering the particle trapping region, which can reduce the function of the particle trapping region.

  [0013] It is desirable to develop new methods to reduce, and preferably eliminate, the problems associated with bead blast particles embedded in the particle capture region. In addition to or as an alternative to utilizing such novel methods to form particle capture regions on the non-sputtered surface of the PVD target, such novel methods include, but are not limited to: Numerous configurations that can come into contact with the material sputtered in the chamber, including one or more surfaces of the chamber walls, coils, guard rings, fasteners, shields, pins, cups, etc. It would be desirable to be applicable for use in the particle trapping region associated with the non-sputtered surface of the element.

  [0014] In one aspect, the invention includes solubilizing the media to remove the bead blast media after the bead blasting process. This medium is initially provided in the form of particles and is used for bead blasting to roughen the surface. The bead blast medium is highly soluble in the solvent, and then the bead blast surface is exposed to the solvent to dissolve the bead blast medium that may be associated with the roughened surface. Typical media may include ammonium chloride and various halide salts containing elements from groups IA and IIA of the periodic table. In certain embodiments, the medium can include one or more alkaline halide salts, such as, for example, sodium chloride or potassium chloride, but in such applications, it is used to remove the medium. The solvent can be an aqueous solution. Other exemplary media can include organic materials (eg, organometallic materials, etc.), but the solvent can include an organic solvent suitable for dissolving the organic material.

  [0015] In one aspect, the invention relates to the use of metal in bead blasting. Bead blasting is used to roughen the surface of PVD components. Such surfaces can include metals (in the form of elemental metals or in the form of alloys), but the metals used for bead blasting have a higher hardness than the metal on the surface of the PVD component. possible. In a particular embodiment, the metal used for bead blasting is in a relatively pure form, in particular having a metal content of 99% or more (by weight).

  [0016] In one aspect, the present invention provides a target / backing plate having a non-sputtering region that extends along a peripheral side of the target and along a ridge proximate to the target. Include. This structure includes an insert provided inside the ridge and includes a material suitable for use in forming the particle trap. In an exemplary embodiment, the target can include tantalum, the backplate can include copper, and the insert can include one or more of aluminum, titanium, and tantalum. is there.

  [0031] The present invention includes a particle trapping region that can be formed on one or more surfaces of a PVD component and a method of forming the particle trapping region. The particle trapping region can be used to trap the material that deposits on these components during the deposition process. [0032] The particle trapping region is formed by treating one or more surfaces of the PVD component with bead blasting and, in some embodiments, machining. If the component thus treated is a sputtering target, the treated surface includes any non-sputtering surface, for example, a sidewall surface, a ridge surface, and / or a non-sputtering surface along the sputtering surface. obtain.

  [0033] The protrusions formed by machining are considered to correspond to macro-scale roughness, and the rough surface formation realized by bead blasting is considered to correspond to micro-scale roughness. Thus, the present invention can include patterns that have one or both of macroscale and microscale roughness and are used in the capture area.

  [0034] It may be advantageous to use both macroscale and microscale patterns. Combining macroscale and microscale patterns can significantly reduce material flaking from the treated surface of the component during the deposition process. In addition, when a microscale rough surface is formed on a macroscale pattern, the problem of peeling off from the deposited thin film can be effectively reduced by reducing the planar or linear deposited thin film. Planar or straight films can be particularly vulnerable to periodic thermal stresses that occur during periodic deposition processes.

  In particular, only macroscale patterns (eg, long machined spirals) can capture redeposited material and form a long thin film within the capture region. Periodic thermal stresses (e.g., stresses associated with different thermal expansion coefficients of the redeposited thin film relative to the base material of the processing component) can lead to delamination of the thin film or redeposited thin film mass from the processing component. When a thin film or lump delaminates from a component, it can fall onto the substrate in close proximity to the component and undesirably form particles inside the layer deposited on the substrate during the deposition process, which Production capacity or output can be reduced.

  [0035] While it may be advantageous to impart both macroscale and microscale roughness to a surface, in some cases only microscale roughness is the preferred mode for capture. Accordingly, the present invention also encompasses embodiments in which microscale roughness is formed on one or more surfaces of a sputtering component that does not have macroscale roughness. Alternatively, the present invention may include embodiments in which macroscale roughness is formed on one or more surfaces of a sputtering component that does not have microscale roughness.

  [0036] Exemplary aspects of the present invention for treating components of a PVD process (particularly for treating a non-sputtered surface of a sputtering target) are described below with reference to FIGS. [0037] Referring to FIGS. 2 and 3, a typical sputtering target structure 10 is illustrated in a top view (FIG. 2) and a cross-sectional view (FIG. 3). Although structure 10 is shown as a monolithic physical vapor deposition target in an exemplary embodiment of the present invention, alternatively, structure 10 is a target / backplate structure (an exemplary target / backplate structure is illustrated in FIGS. It should be understood that this may be as shown in FIG.

  The target structure 10 includes a sputtering surface 12 and a sidewall 14 proximate to the sputtering surface. The structure 10 also includes a ridge 16 that extends around the lower region of the target structure. Although structure 10 is shown as a VECTRA-IMP ™ type target commercially available from Honeywell International Inc., other target structures may be used in various embodiments of the invention. It should be understood that this is possible. [0038] Sputtering surface 12 generally has both a region where material is sputtered in a PVD operation and a region where material is not sputtered in a PVD operation. Such a non-sputtering region may include, for example, a region adjacent to the sidewall 14 and corresponding to a lateral peripheral region of the surface 12.

  [0039] As discussed above, problems associated with the use of the target structure 10 or other target structures in a sputtering operation are that some material scattered from the surface 12 may be exposed to other surfaces of the target structure (side walls 14, ridges). 16, and non-sputtering regions including the non-sputtering region of surface 12). These redeposited materials can eventually fall as particles from the target structure during PVD operations. These particles can accumulate within the sputter deposited layer during PVD operations, adversely affecting the layer properties and / or fall on an electrostatic chuck provided to support the substrate. There is. Accordingly, it is desirable to develop a method for treating sidewalls and / or edges and / or other non-sputtering surfaces of a target in order to avoid particle contamination in the sputter deposited layer.

  [0040] According to one aspect of the present invention, the surface 12 surface (non-sputtering surface), sidewalls 14, and / or ridges 16 are treated by a novel method to reduce particle formation. Such a processing region may span, for example, part or all of the region indicated by bracket 18 in FIG. Using the method of the present invention, treat all of the target non-sputtering surface (whether on surface 12, sidewall 14, or ridge 16) that is exposed to vacuum inside the PVD reaction chamber. It may be particularly recommended to do.

  FIG. 4 shows an enlarged region 20 of the sidewall 14. This side wall has a relatively planar surface 21. [0042] FIG. 5 illustrates the enlarged region 20 after the side wall 14 has been processed to form a pattern of protrusions 22 that extends across the surface of the side wall. The protrusions 22 can be formed using a computer numerical control (CNC) tool, a knurling device, or other suitable machine tool, and can correspond to a spiral pattern. For example, a CNC tool can be used to cut the sidewall 14 to leave the illustrated pattern and / or a knurling device can be pressed into the sidewall 14 to create such a pattern. It is possible to leave. Such a pattern is a repetitive pattern unlike an irregular pattern formed by bead blasting, for example. The pattern of the protrusions 22 may be referred to as a macro pattern to distinguish this pattern from the subsequently formed micropatterns (discussed below).

  [0042] The protrusions 22 may be from about 28 per inch to about 80 per inch, typically about 40 per about 2.54 cm (1 inch). Can be formed to a density. In certain applications, these protrusions can be formed by a tool having from about 28 teeth (TPI) to about 80 TPI, typically about 40 TPI per inch. The tool teeth may have a one-to-one correspondence with the protrusions 22. The protrusions 22 can be formed over the entire surface of the non-sputtering region of the protrusion 16 (FIG. 3) and / or the surface 12 as an alternative or in addition to the formation of protrusions along the sidewall 14.

  [0043] FIG. 6 shows the enlarged region 20 after the protrusion 22 has been subjected to a mechanical force that folds the protrusion. This mechanical force can be supplied by any suitable tool including, for example, a ball or a roller. These bent projections can also be formed using appropriate directional machining with a CNC tool. The bent protrusions define holes 23 between the protrusions, and such holes can function as traps for redeposited materials and / or traps for other particle sources.

  [0044] Referring again to FIG. 3, it is contemplated that the side wall 14 is a proximity sputtering surface 12 and a lateral periphery of the target structure 10 is formed around the sputtering surface. 6 can be understood to form a hole 23 that opens laterally along the side wall. The holes 23 are also considered to be a repeating pattern of the receptacle formed by the bent or curved projections 22. These receptacles 23 can be used to hold vapor deposition materials or other materials that can eventually become one of the particle sources during PVD processing. The receptacles 23 are shown in FIG. 6 to have an inner surface 27 around the inner periphery of these receptacles.

  [0045] When the sputtering surface 12 (FIG. 3) is defined as the upper surface of the target structure 10 (ie, when the target structure is considered to be in the orientation of FIG. 3), the illustrated hole faces downward. Open to. In another aspect of the invention (not shown), the curved protrusion may form a hole that opens upward or sideways in the orientation of FIG. Thus, the present invention provides a sputtering surface defined as the upper surface of the target structure, and a curved protrusion is formed along the sidewall of the target structure to face downward and upward relative to the defined upper surface of the sputtering surface. And an aspect of forming a laterally opening hole along the side wall in one or more lateral orientations.

  For the purpose of explaining the relative orientation of the holes formed by the curved projections, not as indicating any particular orientation of the target structure relative to the external reference frame, the sputtering surface is defined as the top surface. It is noted that Thus, the sputtering surface 12 (FIG. 3) may appear to the outside of the target structure as an upward surface of the target structure, a downward surface of the target structure, or a lateral surface of the target structure. However, for purposes of describing the present disclosure, this surface is considered to be defined as the upper surface in order to understand the relationship of the sputtering surface to the directionality of the opening of the hole 23 formed by the curved protrusion 22. .

  [0046] The hole 23 may advantageously open upward in the orientation in which the target structure 10 is to eventually be used in a sputtering chamber (eg, the chamber 112 of FIG. 1). Thus, it may be advantageous to open the hole in the illustrated downward configuration relative to the sputtering surface 12 defined as the upper surface of the target structure. FIG. 7 illustrates an enlarged region 30 of the structure of FIG. 6, and in particular illustrates a single protrusion 22. [0048] The curved protrusions 22 of FIGS. 6 and 7 are, for example, from about 0.0001 inches to about 0.1 inches from the surface 21 (typically about 0.0254 cm). (About 0.01 inches) and a height "H" of about 0.001 inches to about 1 inch (typically about 0.0686 cm). 027 inches)) repeat distance ("R"). The distance “R” is considered to be the periodic repetition distance of the curved protrusion 22.

  [0049] In certain aspects, the curved protrusions 22 are considered to have bases 25 where these curved protrusions join to the sidewalls 14, and the sidewalls 14 have a surface 15 extending between the bases of the curved protrusions. it is conceivable that. The curved protrusion typically has a maximum height (“H”) of about 0.0001 inches to about 0.01 inches from the sidewall surface 15.

  [0050] FIGS. 8 and 9 show the protrusion 22 after it has been processed to form a microstructure 32 that extends as a hole or depression along the protrusion 22. Such treatment preferably extends into the receptacle 23 (as shown) to roughen the inner surface 27. Both of these microstructures define the roughness of the microstructure.

  [0051] For example, one or both of a chemical etching solution and a mechanical rough surface formation can be used for the treatment of the protrusions 22. Typical mechanical roughening procedures include exposure to a squeezed stream of particles (eg, bead blasting) or contact with stiff bristles (such as wire bristles). Typical chemical etchants include solutions that chemically puncture the material of protrusions 22 and include strong basic solutions, weak basic solutions, strong acidic solutions, weak acidic solutions, and neutral solutions. Can be.

[0052] When the microstructure 32 is formed using bead blasting, the particles used to form the microstructure are, for example, olivine, silicon carbide, aluminum oxide, solid H ₂ O ( Ice), solid carbon dioxide, and a salt (eg, a salt of a bicarbonate such as sodium bicarbonate). Additionally or alternatively, the particles may include one or more metallic materials that are at least as hard as the material into which the microstructure is to be made.

[0053] If the particles used for bead blasting include non-volatile materials, a cleaning step can be introduced after formation of the recess 32 to remove these particles. For example, if the particles include silicon carbide or aluminum oxide, a cleaning step can be used, where the protrusions 22 are exposed to a bath or stream of cleaning material and / or a suitable brushing tool (wire brush). Etc.). A suitable stream may be a stream comprising solid H ₂ O or solid carbon dioxide particles. If the particles initially used to form the depressions 32 consist essentially of or consist of volatile particles (such as solid ice or solid CO ₂ ), the cleaning step described above Can be omitted.

[0054] In some embodiments, the bead blast media may be 24 grit Al ₂ O ₃ media, for example, about 0.025 to about 100 μm (about 1 to about 4000 microinches). Performable with RA, preferably about 1.25 to about 50 μm (about 50 to about 2000 microinches) RA, typically about 2.5 to about 7.5 μm (about 100 to about 300 microinches) RA It is.

  [0055] In some embodiments, the bead blasting medium can include a material that is highly soluble in a suitable solvent. In that case, the solvent can be used to remove the bead blast media from the treated surface. In particular, the bead blasting medium can include salts or other mixtures that are readily soluble in a suitable solvent (such as an aqueous solvent, alcohol solvent, non-polar organic solvent, etc.). Thus, the bead blast medium can be essentially completely removed from the surface by a suitable solvent.

  [0056] In a typical application using a bead blast medium soluble in a suitable solvent, groups IA and IIA of the periodic table (for groups IA and IIA are lithium, sodium, potassium, rubidium, cesium, francium, Bead blasting media containing one or more halide salts containing elements from (including beryllium, magnesium, calcium, strontium, barium, and radium) can be used, and from an treated surface using an aqueous solvent The bead blasting medium can be washed. As will be appreciated by those skilled in the art, halide salts include elements from groups IA and IIA of the periodic table and group VIIA (group VIIA includes fluorine, chlorine, bromine, iodine, and astatine). Combinations with elements can be included. Another exemplary salt that is water soluble and can be used as a bead blasting medium in various aspects of the present invention is ammonium chloride.

[0057] Halogen compounds are just one example of salts that are highly soluble in aqueous solvents. In addition to halogen compounds, many other salts are known to have high solubility in aqueous solvents, and such other salts can also be used in various embodiments of the present invention. Non-halide salts that are soluble in aqueous solvents include, for example, various carbonates (such as calcium carbonate) and various hydroxides (including, for example, metal hydrides). A typical carbonate is sodium bicarbonate (Na ₃ (CO ₃ ) (HCO ₃ )) · 2 (H ₂ O).

  [0058] The aqueous solvent described above is just one of many types of solvents that can be used in various embodiments of the present invention, and various bead blast media can be removed using solvents other than water. Should be understood. For example, various organic particles can be used as the bead blasting media, which can subsequently be dissolved in a suitable organic solvent. The organic particles can include organometallic materials in some embodiments of the present invention.

  [0059] The use of a soluble bead blasting medium can simplify the cleaning of the bead blasted surface. In particular, removing the media with a suitable solvent can eliminate the prior art problems associated with embedded bead blast particles (typical prior art problems are discussed above in the background section of this disclosure. Argued). In certain aspects, the use of highly soluble bead blasting media can prevent the risk of arcing that may be associated with embedded beads and on particle traps formed in accordance with aspects of the present invention. It can help promote redeposited thin film deposits.

  [0060] Highly soluble beads and methods of using suitable solvents to remove the beads can allow micro-scale surface formation that is almost none even if embedded beads are present (Figure 8 and 9). A microscale rough surface substantially free of beads can minimize periodic thermal stresses by avoiding bead contamination. Also, microscale rough surfaces that are substantially free of beads are unlike small redeposition materials, unlike sputter traps that have some associated beads (eg, silicon carbide or aluminum oxide beads). Can have.

  [0061] The soluble media discussed above can be used to avoid problems associated with this media by improving the removal of the embedded bead blast media. In another aspect of the invention, the problems associated with embedded bead blast media are mitigated by using media that are compatible with the desired use of sputtering components being processed by such media. Thus, some of the media can remain embedded in the processed components without adversely affecting the use of such components in sputtering applications.

  [0062] Typical compatible media used for bead blasting of PVD components can include, consist essentially of, or consist of metals in the form of elements or alloys. In general, metal materials are considered too soft, so that conventional methods of treating PVD components do not use metal materials for bead blasting. However, in one aspect of the invention, it will be appreciated that a metal material of suitable hardness can be used in a bead blasting medium. Metal particles are generally softer than normal bead blast particles, but if these metal particles are at least as hard as the surface to be roughened, these particles can provide adequate roughening. it can. The hardness can be ascertained by any suitable scale including, for example, the Brinell scale, the Vickers scale, the Knoop scale, and the Morse scale.

  [0063] Metal particles are considered compatible with a target surface if these particles contain the same composition as the target surface or do not impart undesirable properties during the sputtering operation. For example, if the sputtering target includes tantalum and is to be used to form a barrier layer, the bead blast particles used to roughen the non-sputtering region of the target are titanium, molybdenum, tantalum. , Tungsten, and cobalt (all of which can be used to form a barrier material similar to the target tantalum), or can consist essentially of, or they It can consist of Other materials that may be considered compatible with the treated surface are those that can be easily removed from the treated surface so that the particles are not associated with the surface in the sputtering operation. However, it is generally difficult to remove metal particles from the surface of a sputtering component, so that metal particles that are compatible with a particular sputtering process are similar in materials and semiconductor devices that are sputter deposited during that process. In general, the particles are formed from one or more substances having a function.

  [0064] Roughening of tantalum-containing PVD components or titanium-containing PVD components can be particularly commercially important. Sputter deposition of tantalum or titanium, especially deposition of tantalum or titanium in the presence of nitrogen, presents more problems than other processes with regard to redeposition and deposition along non-sputtered regions and with respect to subsequent undesirable particle formation. Can have. Tantalum or titanium is often sputter deposited in the presence of nitrogen to form a barrier material comprising tantalum nitride or titanium nitride. Thus, the sputtering trap formation method of the present invention may be particularly advantageous for treating tantalum or titanium sputtering targets used in the formation of barrier materials.

  [0065] A typical bead blasting material comprising a metallic medium can be a material containing about 5% to about 30% (by volume) of metal powder (such a metal is at least about 99% pure by weight). Is). The bead blast material can include, for example, about 20% metal powder, with the remainder being, for example, carbonate (sodium bicarbonate, potassium carbonate, sodium bicarbonate, etc.), halide salts (sodium chlorate, chlorine). Non-metallic particles, such as potassium acid) or any other suitable medium.

  The components of the media used in addition to the metal material are preferably highly soluble in a suitable solvent so that such components can be easily removed from the treated surface. In some embodiments, the bead blasting medium comprises a first set of particles consisting essentially of one or both of a metal alloy and an elemental metal, and a second set of a plurality of particles soluble in an aqueous or organic solvent. And particles. The volume-to-volume ratio (v / v) of the first set of particles to the second set of particles in the medium may be about 1: 3 or less, and in certain embodiments from 1:10 to 1 : 3 or less.

  [0066] In a particular embodiment of the invention, the tantalum target bonded to the aluminum backplate is formed on a tantalum sidewall surface, optionally an aluminum surface, similar to the process shown in FIGS. On top, it is machined to provide a groove. The macro-roughened tantalum is then micro-roughened using a mixture of tungsten powder (usually 200 grit at about 552 kPa (80 psi)) and baking soda (sodium bicarbonate) particles in a volume ratio of 1:10. To be. Tungsten provides a blasting medium that is hard enough to create a textured surface on tantalum, but tungsten adheres well to tantalum and has a foreign-mattering effect on the chambers used to form barrier materials. As a result, the use of tantalum bead blasting media does not introduce problematic foreign matter into the sputtering chamber.

  To remove any loosely embedded tungsten, the first blasting can be followed by a pure baking soda blasting. Therefore, any tungsten remaining in the particle trap will be firmly embedded in the target surface and will not fall in the chamber during the sputtering process. Micro-roughening can be performed on a portion of the aluminum back plate as well as on a portion of the tungsten so that the particle trapping region reaches on the aluminum back plate, or alternatively, It can be implemented only on the tantalum macro rough surface region. In some embodiments, macro roughening of the tantalum surface can be omitted, and a rougher surface can be created using a higher grit tungsten at a higher blast pressure. Such rough surfaces can be treated by further micro-roughening or the micro-roughening can be omitted.

  [0067] The tungsten powder of the above-discussed aspects of the invention can be used in combination with tantalum powder, or tantalum can be used as a substitute for tungsten powder. If the target is a titanium target, the titanium powder can be mixed with baking soda and used as an abrasive. Alternatively, baking soda can be replaced with any suitable carrier particles. The carrier particles are preferably easily removable, and therefore the carrier particles are preferably easily dissolved in the washing solvent used following bead blasting. Thus, the metal particles can be used with the highly soluble particles discussed earlier in this disclosure.

  [0068] It is contemplated that the sidewall 14 shown in the processing steps of FIGS. 8 and 9 has a surface that includes a capture zone having both macroscale and microscale structures therein. In particular, the protrusions 22 can have a length of about 0.01 inch and are considered to be a macroscale characteristic structure formed on a substrate. The depression formed inside the protrusion is considered to be a microscale structure formed along the surface of the protrusion 22. Combining microscale and macroscale structures can alleviate and even prevent the problems previously described in this disclosure with respect to unwanted incorporation of particles into the sputter deposited layer. The microscale structure formed throughout the macroscale structure can advantageously reduce arcing that could otherwise occur in PVD processes in some embodiments, and in some embodiments. It can be completely prevented.

  [0069] While the exemplary embodiments of the invention described herein form the microstructure on the protrusion after bending the protrusion 22, the present invention forms the microstructure before the protrusion is bent. It should be understood that other aspects (not shown) are encompassed. In particular, instead of bending and then bead blasting and / or chemical etching, the protrusion 22 can be subjected to bead blasting and / or chemical etching and then bent at the processing stage of FIG.

  [0070] The protrusions 22 of FIGS. 5-9 can be formed along part or all of the region 18 of FIG. Thus, the protrusions can extend along at least a portion of the sidewall 14 and / or along at least a portion of the ridge 16 and / or along a lateral peripheral region that is not sputtered by the surface 12. In certain embodiments, these protrusions extend along the entire sidewall 14 and / or extend along the entire protrusion 16 and / or extend along the entire lateral peripheral region that is not subject to sputtering of the face 12. It will be.

  [0071] FIGS. 2 and 3 illustrate a monolithic target structure. One skilled in the art will also recognize that the sputtering target structure may include a target / backplate structure. In particular, the sputtering target can be joined to the backplate prior to placing the target in a sputtering chamber (such as the chamber described with reference to FIG. 1). The target / backplate structure may have any desired shape, including the shape of the monolithic target of FIGS. The backplate can be made of a material that is less expensive than the target, easier to manufacture than the target, or has other desirable properties that are not available on the target. A back plate is used to hold the target in the sputtering chamber. The present invention can be used to process a target / backplate structure in a manner similar to that described in FIGS. 2-9 for processing a monolithic target structure.

  [0072] FIGS. 10 and 11 illustrate an exemplary target / backing structure (or assembly) 200 that can be processed according to the method of the present invention. When referring to FIGS. 10 and 11, like reference numerals used in the description of FIGS. 2-4 above are used where appropriate.

  [0073] The structure 200 includes a target 202 joined to a backplate 204. The target and backplate are joined at the interface 206 in the illustrated assembly. The bond between the target 202 and the back plate 204 may be any suitable bond including, for example, a soldered bond or a diffusion bond. Target 202 may include any desired material, including metals, ceramics, and the like. In certain aspects, the target may include one or more of the materials described above with respect to the target 10 of FIGS. Backplate 204 can include any suitable material or combination of materials, but will often include one or more metals, such as, for example, one or more metals of Al, Cu, and Ti. .

  [0074] The structure 200 has a shape similar to the target structure 10 of FIGS. Accordingly, the structure 200 has a sputtering surface 12, a sidewall 14, and a ridge 16. Any of the various non-sputtering surfaces of structure 200 can be treated by the method of the present invention in a manner similar to that described above with reference to FIGS. Thus, all or part of the illustrated region 18 of the structure 200 can be processed.

  [0075] The difference between the structure 200 of FIG. 11 and the structure 10 of FIG. 3 is that the side wall 14 of the structure of FIG. 11 includes the side wall of the back plate (204) and the side wall of the target (202). The side wall 14 of the 3 structure contained only the target side wall. Thus, the processing region 18 of the structure of FIG. 11 may include particle traps formed along the sidewalls of the backplate 204 and / or particle traps formed along the sidewalls of the target 202. Additionally or alternatively, such processing regions include particle traps formed along the ridge 16 and / or particle traps formed along the non-sputtered portion of the surface 12. Can be. These particle traps can be formed by the same method as described with reference to one or more embodiments of FIGS.

  [0076] Before or after the target 202 of the structure 200 is bonded to the backplate, the target can be processed to form particle traps along the sidewall regions and / or non-sputtered regions of the sputtering surface. Similarly, before or after the back plate 204 of this structure is joined to the target, the back plate can be processed to form particle traps along the sidewall region and / or the edge region. Typically, both the target and the backplate have one or more surfaces that are treated to form particle traps, and the treatment of the target and / or backplate of the structure 200 involves the target and backplate. It will be done after joining the target to the backplate so that it can be processed simultaneously.

  [0077] Other aspects of the invention are discussed with reference to FIGS. The problems that can arise with the processes described above for using compatible metal particles to form a particle capture region along a target structure are that even if the particles are properly attached to the target, the particles Adhesion of the back plate structure to the back plate can be inadequate. Thus, even if the particles are compatible with the target material, the particles may not be compatible with the backplate. The embodiments of FIGS. 12-14 can overcome such problems.

  [0078] FIG. 12 shows a target / backplate structure 300 that includes a backplate 302, a target 304, and an insert 306 between the target and the backplate. FIGS. 13 and 14 illustrate a target / backplate structure 320 that includes a backplate 322, a target 324, and an insert 326 between the target and the backplate. Each of the structures 300 and 320 includes a region 18 that is ultimately to be processed to form a particle trap, such as the surface of the target (304 or 324) and the surface of the insert (306 or 326). Are included, but the region of the back plate (302 or 322) is not included.

  [0079] The targets of FIGS. 12-14 can include, for example, high-purity tantalum (eg, tantalum having a purity of 99.9% by weight or more), and the back plate is copper or a copper alloy (copper). / In some embodiments, and in some embodiments, the backing plate can be copper or a copper alloy having a purity of 99% by weight or more), and the insert region has a purity of 99% by weight or more. Tantalum, titanium, or aluminum. Accordingly, the backplate may comprise, consist essentially of, or consist of a first composition, and the target may comprise, or consist essentially of, a second composition that is different from the first composition. Or the insert is considered to comprise, consist essentially of, or consist of a third composition different from the first and second compositions. . The target, back plate, and insert may be homogeneous in composition (as shown), or in other embodiments one or more of the target, back plate, and insert may have several compositions. (For example, a stack having different compositions) may be included.

  [0080] The various metals discussed above as being compatible with tantalum may be incompatible with copper, but generally are compatible with titanium or aluminum in addition to compatibility with tantalum. Thus, the insert (306 or 326) can be used with the target and backplate so that the particle capture area extends throughout the metal that is compatible with the metal particles that will ultimately be used to treat this area. Between. In some aspects, the present invention may have the particular problem that a Ta target bonded to a Cu alloy backplate will not cause the bounced Ta to adhere to the Cu backplate and thus easily peel off from the backplate. Including the recognition. The intermediate layer or ring material of the insert (306 or 326) can be selected to be more suitable for Ta deposition (chemical or metallurgical bonding) than Cu backing material. The insert (306 or 326) may be a homogeneous single composition (as shown) or may comprise a composite composition. Also, the illustrated insert can be replaced by a stack of several inserts in other aspects of the invention (not shown).

  [0081] Regions 18 of FIGS. 12-14 may include both macroscale and microscale roughening, or alternatively, processing only to form microscale roughening. As may be done, it may be processed using the methods discussed above with reference to FIGS. In embodiments where both microscale roughening and macroscale roughening are used, macroscale roughening can be performed before or after microscale roughening. However, since the macro-scale rough surface formation is rougher than the micro-scale rough surface formation, the macro-scale rough surface formation is preferably performed before the micro-scale rough surface formation.

  [0082] The difference of the embodiment of FIGS. 13 and 14 to the embodiment of FIG. 12 is that the insert 306 of FIG. 12 is a solid circle or other suitable shape when viewed from above, while The inserts 326 of 13 and 14 are annular when viewed from above, and in the illustrated embodiment are annular rings when viewed from above. In some aspects, the insert 306 in FIG. 12 is considered to represent a class of solid geometries, and the insert 326 is considered to represent a class of hollow geometries.

  [0083] The target of FIG. 12 is considered to have a mating surface along the entire insert, and the targets of FIGS. 13 and 14 are partially along the insert and partially along the backplate, It is considered to have a bonding surface. In other words, the structure of FIGS. 12-14 illustrates that the insert is between at least a portion of the target and the backplate, and the structure of FIG. FIG. 13 and 14 show that the insert is between the entire target and the back plate.

  [0084] The structures of FIGS. 12 and 13 can be formed by any suitable method. For example, in a typical method, the insert is first bonded to the backplate by an appropriate bond (eg, including a soldered bond or diffusion bond), and then the target is properly bonded (eg, a soldered bond or diffusion). To the insert / backplate combination. Alternatively, the insert is first bonded to the target by a suitable bond (eg, including a soldered bond or diffusion bond) and then the target / insert combination is properly bonded (eg, a soldered bond or (Including diffusion bonding) to the back plate. As yet another example, the target, backplate, and insert can all be interconnected simultaneously.

  [0085] Regardless of how the target, backplate, and insert are joined together, the particle capture region can be formed throughout the region 18 after the target, backplate, and insert are joined together. Or at least a portion can be formed before one or more of the target, backplate, and insert are joined together. For example, a macro-scale roughening region of the type shown in FIG. 5 is formed along the surface of the target and / or insert before joining the target and / or insert into the target / backplate structure. Is possible. As another example, the bending of FIGS. 6 and 7 and / or the microscale roughening of FIGS. 8 and 9 may be performed before the target and / or insert is joined into the target / backplate configuration. It can be implemented along the surface of the insert. In yet another embodiment, all of the processing steps of FIGS. 5-9 can be performed after joining the target, back plate, and insert into the target / back plate structure.

  [0086] The methods described above for processing non-sputtering regions of a sputtering target are numerous suitable for use in a number of vapor deposition processes (including physical vapor deposition (PVD) equipment, chemical vapor deposition (CVD) equipment, etc.). It can be used for the surface treatment of these components, and it can be used while maintaining the desired roughness control. For example, the method can be used to treat surfaces of PVD device cups, pins, shields, coils, guard rings, fasteners, interior walls, and the like.

It is sectional drawing which shows the physical vapor deposition apparatus of a prior art typically, and the time of physical vapor deposition (for example, sputtering) process is shown. FIG. 3 is a top view schematically illustrating a typical target structure suitable for use in the method of the present invention. FIG. 3 is a cross-sectional view schematically shown along line 3-3 in FIG. 2. FIG. 4 shows an enlarged region of the target structure of FIG. 3 (the region labeled “4” in FIG. 3), showing that the exemplary method of the present invention is in a pre-processing stage. FIG. 5 is an enlarged view of the area of FIG. 4, showing the processing stage following the stage of FIG. 4. FIG. 6 is an enlarged view of the area of FIG. 4, showing the processing stage following the stage of FIG. 5. It is an enlarged view which shows a part of structure of FIG. FIG. 7 is an enlarged view of the area of FIG. 4, showing the processing stage following the stage of FIG. 6. It is an enlarged view which shows a part of structure of FIG. FIG. 3 is a top view schematically illustrating an exemplary target / backplate structure suitable for use in the method of the present invention. It is sectional drawing shown typically along the line 11-11 of FIG. 1 is a cross-sectional view schematically illustrating an exemplary target / backplate structure according to one embodiment of the present invention. FIG. 13 is a cross-sectional view schematically illustrating an exemplary target / backplate structure according to one embodiment of the present invention, similar to the structure of FIG. FIG. 14 is a top view schematically showing the target / backplate structure of FIG. 13 along line 14-14 of FIG. 13.

Claims (56)

  A method of treating a component of a vapor deposition apparatus, wherein the component includes a composition having a first hardness, the method comprising a bead blast medium comprising particles having a second hardness equal to or greater than the first hardness. By exposing the surface of the component to bead blasting, wherein the particles consist essentially of one or both of metal alloys and elemental metals.   The method of claim 1, wherein the component surface consists essentially of tantalum and the particles include one or more metal components compatible with the tantalum.   The method of claim 1, wherein the component surface consists essentially of tantalum and the particles comprise one or more of titanium, molybdenum, tantalum, tungsten, and cobalt.   The method of claim 1, wherein the component is a sputtering target consisting essentially of tantalum and the particles consist essentially of one or more of titanium, molybdenum, tantalum, tungsten, and cobalt.   The component is a sputtering target consisting essentially of tantalum, the particles are a first set of particles contained by the bead blast media, and the bead blast media is a first set of a plurality of particles. Including a second set of particles different from the particles, wherein the first set of particles consists essentially of tungsten and the second set of particles consists essentially of sodium bicarbonate. The method of claim 1, wherein the volume ratio of the first set of particles to the second set of particles in the bead blasting medium is about 1:10. The method
Forming a pattern of protrusions along the surface of the component;
The method of claim 1, further comprising bending the protrusion.   The method of claim 6, wherein the component surface consists essentially of tantalum and the particles comprise one or more of titanium, molybdenum, tantalum, tungsten, and cobalt.   The method according to claim 6, wherein the bead blasting is performed before the step of forming the pattern of the protrusions.   The method of claim 6, wherein the bead blasting is performed after the step of forming the pattern of the protrusions and before the step of bending the protrusions.   The method of claim 6, wherein the bead blasting is performed after the step of bending the protrusion.   The particles are a first set of particles contained by the bead blast medium, the bead blast medium comprising a second set of particles different from the first set of particles; The method of claim 1, wherein the second set of particles is soluble in an aqueous solution.   The method of claim 11, wherein the volume-to-volume ratio of the first set of particles to the second set of particles within the bead blast medium is about 1: 3 or less.   12. The volume to volume ratio of the first set of particles to the second set of particles within the bead blast medium is about 1: 3 or less and 1:10 or more. The method described in 1.   12. The method of claim 11, wherein the second set of particles comprises one or more salts selected from the group consisting of alkaline halide salts and ammonium halide salts.   12. The method of claim 11, wherein the second set of particles comprises one or more salts selected from the group consisting of metal hydroxides.   12. The plurality of particles of the second set comprises one or more salts selected from the group consisting of halide salts containing elements selected from Groups IA and IIA of the Periodic Table. The method described.   The particles are a first set of particles contained by the bead blast medium, the bead blast medium comprising a second set of particles different from the first set of particles; The method of claim 1, wherein the second set of particles is soluble in an organic solution.   The method of claim 17, wherein the second set of particles comprises one or more organometallic materials. A method of forming a target / backplate structure, comprising:
Providing a back plate comprising a first composition;
Providing a target comprising a second composition different from the first composition;
Providing an insert having a third composition different from the first and second compositions;
Joining the target, back plate and insert in one configuration, wherein the insert is between at least a portion of the target and the back plate, the configuration comprising Joining, having a surface extending along a portion of the target and a portion of the insert;
Forming a particle trapping region along the surface, the particle trapping region including a pattern of curved protrusions extending along the portion of the insert and along the portion of the target. Forming a particle trapping region wherein the curved projections form a hole and at least some of the holes open laterally along the target / backplate structure. After the joining step, the step of forming the particle capture region is performed, and the step of forming comprises
Forming a pattern of protrusions along the surface;
Bending the protrusion;
20. The method of claim 19, comprising exposing the protrusion to bead blasting to form a microstructure on the protrusion.   20. The method of claim 19, wherein the bead blasting uses a medium comprising particles having a hardness equal to or greater than the hardness of the second composition, the particles consisting essentially of one or both of a metal alloy and elemental metal. .   The particles are a first set of particles contained by the bead blast medium, and the bead blast medium includes a second set of particles different from the first set of particles. 24. The method of claim 21, wherein the second set of particles is soluble in an aqueous or organic solution.   20. The method of claim 19, wherein at least a portion of the particle trapping region is formed prior to the joining step. The joining step includes
Embedding the insert in the back plate and joining the insert to the back plate;
20. The method of claim 19, comprising joining the target to the insert after the insert is joined to the backplate.   The method of claim 19, wherein the second composition comprises tantalum.   The method of claim 19, wherein the second composition consists essentially of tantalum.   The method of claim 19, wherein the second composition comprises tantalum.   20. The method of claim 19, wherein the first composition comprises copper, the second composition comprises tantalum, and the third composition comprises titanium.   20. The method of claim 19, wherein the first composition comprises copper, the second composition consists essentially of tantalum, and the third composition consists essentially of titanium.   The method of claim 19, wherein the first composition comprises copper, the second composition comprises tantalum, and the third composition comprises titanium.   20. The method of claim 19, wherein the second composition comprises tantalum and the third composition comprises one or more of aluminum, tantalum, and titanium.   The method of claim 19, wherein the target has a bonding surface proximate the backing plate, the entire bonding surface contacting the insert.   20. The method of claim 19, wherein the target has a bonding surface proximate to the back plate, and only a portion of the bonding surface is in contact with the insert.   20. The method of claim 19, wherein the insert is a solid geometry of the third composition.   20. The method of claim 19, wherein the insert is a hollow geometry of the third composition.   The method of claim 19, wherein the insert is a solid circle of the third composition.   20. The method of claim 19, wherein the insert is an annular ring of the third composition. A target / back plate structure,
A back plate comprising a first composition;
A target comprising a second composition different from the first composition;
An insert between at least a portion of the target and the backplate, the insert having a third composition different from the first and second compositions;
The target / backplate structure includes a particle capture region extending along a portion of the target and along a portion of the insert, the particle capture region being along the portion of the insert. And a pattern of curved protrusions extending along the portion of the target, the curved protrusions forming holes, at least some of the holes opening laterally along the target / backplate structure / Back plate structure.   40. The target / backplate structure of claim 38, wherein the second composition comprises tantalum.   40. The target / backing plate structure of claim 39, wherein the third composition comprises titanium.   40. The target / backing plate structure of claim 38, wherein the second composition consists essentially of tantalum.   42. The target / backplate structure of claim 41, wherein the third composition comprises titanium.   40. The target / backplate structure of claim 38, wherein the second composition comprises tantalum.   44. The target / backing plate structure of claim 43, wherein the third composition comprises titanium.   39. The target / backplate structure of claim 38, wherein the first composition comprises copper, the second composition comprises tantalum, and the third composition comprises titanium.   40. The target / backplate structure of claim 38, wherein the first composition comprises copper, the second composition consists essentially of tantalum, and the third composition consists essentially of titanium.   40. The target / backplate structure of claim 38, wherein the first composition comprises copper, the second composition comprises tantalum, and the third composition comprises titanium.   39. The target / backplate structure of claim 38, wherein the second composition comprises tantalum and the third composition comprises one or more of aluminum, tantalum, and titanium.   39. The target / backplate structure of claim 38, wherein the target has a bonding surface proximate to the backplate, wherein the entire bonding surface is in contact with the insert.   39. The target / backplate structure of claim 38, wherein the target has a bonding surface proximate to the backplate, and only a portion of the bonding surface is in contact with the insert.   39. The target / backplate structure of claim 38, wherein the insert is a solid geometry of the third composition.   39. The target / backing board structure of claim 38, wherein the insert is a hollow geometry of the third composition.   39. The target / backplate structure of claim 38, wherein the insert is a solid circle of the third composition.   39. The target / backplate structure of claim 38, wherein the insert is a solid circle of the third composition and embedded within the backplate.   39. The target / backplate structure of claim 38, wherein the insert is an annular ring of the third composition. 39. The target / backplate structure of claim 38, wherein the insert is an annular ring of the third composition and embedded within the backplate.

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