Patent Application
20080041720
Prior Art
Prior Art
Prior Art
Prior Art
Prior Art
Prior Art
Prior Art
A PVD target assembly has been produced that a) eliminates pits and cracks at the interface of the sputtering material and supporting member, b) provides for flexibility in the location of the bond line to maximize the mechanical integrity of the assembly, and c) is manufactured efficiently with the minimum number of processing steps to produce the final product. For the purposes of interpreting this disclosure and the claims that follow, a target is considered to have an extended sidewall if the ratio of the vertical dimension “y” to the horizontal dimension “x” is at least about 0.125. In some embodiments, the ratio of the vertical dimension to the horizontal division is at least about 0.200. In other embodiments, the ratio of the vertical dimension to the horizontal division is at least about 0.225. In yet other embodiments, the ratio of the vertical dimension to the horizontal division is at least about 0.275.
In accomplishing the manufacturing advances described herein, the E-beam welding processes have been replaced by at least one of the following solid state bonding and forming processes: a) uni-axial contact die forging (
Methods for producing PVD sputtering targets include: a) bonding a surface material to a core material to produce a rough part; b) forming the rough part; and optionally in some embodiments, c) utilizing at least one machining step to form the target. In addition, methods for producing PVD sputtering targets include: a) concurrently bonding a surface material to a core material to produce a rough part and forming the rough part; and optionally, in some embodiments, b) utilizing at least one machining step to form the target
In one contemplated method to produce these PVD targets, a solid state/diffusion bonded rough part is manufactured, the part is then formed utilizing a forming method, such as spin-forming or press forming, and then at least one machining step is conducted on the spin formed or press formed part (for example, the rough blank). In some embodiments, these methods and processes can be combined or conducted concurrently to produce a more efficient and economical method. For example, as shown in
Diffusion bonding the part comprises bonding the sputtering material to the backing plate by any suitable solid state bonding method—such as uni-axial contact die forging, explosion bonding, friction bonding, or hot isostatic pressing (HIP). The rough blank is then spin-formed or press formed instead of rough machining to shape and form the backside (backing plate) of the target. Finally, at least one machining step is performed on the rough target to produce the final target. The resulting target comprises fewer defects (such as weld pits) than those made by conventional E-beam welding and also is made using fewer processing steps.
The methods and apparatus described herein are especially useful in producing unconventional, uniquely-sized targets, such as the 300 mm ULVAC Entron EX PVD target and new targets being produced to utilize in the production of large LCD and plasma displays.
Sputtering targets and sputtering target assemblies contemplated and produced herein comprise any suitable shape and size depending on the application and instrumentation used in the PVD process. Sputtering targets contemplated and produced herein comprise a surface material and a core material (which includes the backing plate). The surface material and core material may generally comprise the same elemental makeup or chemical composition/component, or the elemental makeup and chemical composition of the surface material may be altered or modified to be different than that of the core material. However, in embodiments where it may be important to detect when the target's useful life has ended or where it is important to deposit a mixed layer of materials, the surface material and the core material may be tailored to comprise a different elemental makeup or chemical composition.
The surface material is that portion of the target that is intended to produce atoms and/or molecules that are deposited via PVD to form the surface coating/thin film.
Sputtering targets contemplated herein may generally comprise any material that can be a) reliably formed into a sputtering target; b) sputtered from the target when bombarded by an energy source; and c) suitable for forming a final or precursor layer on a wafer or surface. Materials that are contemplated to make suitable sputtering targets are metals, metal alloys, conductive polymers, conductive composite materials, dielectric materials, hardmask materials and any other suitable sputtering material. As used herein, the term “metal” means those elements that are in the d-block and f-block of the Periodic Chart of the Elements, along with those elements that have metal-like properties, such as silicon and germanium. As used herein, the phrase “d-block” means those elements that have electrons filling the 3d, 4d, 5d, and 6d orbitals surrounding the nucleus of the element. As used herein, the phrase “f-block” means those elements that have electrons filling the 4f and 5f orbitals surrounding the nucleus of the element, including the lanthanides and the actinides. Preferred metals include titanium, silicon, cobalt, copper, nickel, iron, zinc, vanadium, zirconium, aluminum and aluminum-based materials, tantalum, niobium, tin, chromium, platinum, palladium, gold, silver, tungsten, molybdenum, cerium, promethium, thorium, ruthenium or a combination thereof. More preferred metals include copper, aluminum, tungsten, titanium, cobalt, tantalum, magnesium, lithium, silicon, manganese, iron or a combination thereof. Most preferred metals include copper, aluminum and aluminum-based materials, tungsten, titanium, zirconium, cobalt, tantalum, niobium, ruthenium or a combination thereof. Examples of contemplated and preferred materials, include aluminum and copper for superfine grained aluminum and copper sputtering targets; aluminum, copper, cobalt, tantalum, zirconium, and titanium for use in 200 mm and 300 mm sputtering targets, along with other mm-sized targets; and aluminum for use in aluminum sputtering targets that deposit a thin, high conformal “seed” layer or “blanket” layer of aluminum surface layers. It should be understood that the phrase “and combinations thereof” is herein used to mean that there may be metal impurities in some of the sputtering targets, such as a copper sputtering target with chromium and aluminum impurities, or there may be an intentional combination of metals and other materials that make up the sputtering target, such as those targets comprising alloys, borides, carbides, fluorides, nitrides, silicides, oxides and others.
The term “metal” also includes alloys, metal/metal composites, metal ceramic composites, metal polymer composites, as well as other metal composites. Alloys contemplated herein comprise gold, antimony, arsenic, boron, copper, germanium, nickel, indium, palladium, phosphorus, silicon, cobalt, vanadium, iron, hafnium, titanium, iridium, zirconium, tungsten, silver, platinum, ruthenium, tantalum, tin, zinc, lithium, manganese, rhenium, and/or rhodium. Specific alloys include gold antimony, gold arsenic, gold boron, gold copper, gold germanium, gold nickel, gold nickel indium, gold palladium, gold phosphorus, gold silicon, gold silver platinum, gold tantalum, gold tin, gold zinc, palladium lithium, palladium manganese, palladium nickel, platinum palladium, palladium rhenium, platinum rhodium, silver arsenic, silver copper, silver gallium, silver gold, silver palladium, silver titanium, titanium zirconium, aluminum copper, aluminum silicon, aluminum silicon copper, aluminum titanium, chromium copper, chromium manganese palladium, chromium manganese platinum, chromium molybdenum, chromium ruthenium, cobalt platinum, cobalt zirconium niobium, cobalt zirconium rhodium, cobalt zirconium tantalum, copper nickel, iron aluminum, iron rhodium, iron tantalum, chromium silicon oxide, chromium vanadium, cobalt chromium, cobalt chromium nickel, cobalt chromium platinum, cobalt chromium tantalum, cobalt chromium tantalum platinum, cobalt iron, cobalt iron boron, cobalt iron chromium, cobalt iron zirconium, cobalt nickel, cobalt nickel chromium, cobalt nickel iron, cobalt nickel hafnium, cobalt niobium hafnium, cobalt niobium iron, cobalt niobium titanium, iron tantalum chromium, manganese iridium, manganese palladium platinum, manganese platinum, manganese rhodium, manganese ruthenium, nickel chromium, nickel chromium silicon, nickel cobalt iron, nickel iron, nickel iron chromium, nickel iron rhodium, nickel iron zirconium, nickel manganese, nickel vanadium, tungsten titanium and/or combinations thereof.
As far as other materials that are contemplated herein for sputtering targets, the following combinations are considered examples of contemplated sputtering targets (although the list is not exhaustive): chromium boride, lanthanum boride, molybdenum boride, niobium boride, tantalum boride, titanium boride, tungsten boride, vanadium boride, zirconium boride, boron carbide, chromium carbide, molybdenum carbide, niobium carbide, silicon carbide, tantalum carbide, titanium carbide, tungsten carbide, vanadium carbide, zirconium carbide, aluminum fluoride, barium fluoride, calcium fluoride, cerium fluoride, cryolite, lithium fluoride, magnesium fluoride, potassium fluoride, rare earth fluorides, sodium fluoride, aluminum nitride, boron nitride, niobium nitride, silicon nitride, tantalum nitride, titanium nitride, vanadium nitride, zirconium nitride, chromium silicide, molybdenum silicide, niobium silicide, tantalum silicide, titanium silicide, tungsten silicide, vanadium silicide, zirconium silicide, aluminum oxide, antimony oxide, barium oxide, barium titanate, bismuth oxide, bismuth titanate, barium strontium titanate, chromium oxide, copper oxide, hafnium oxide, magnesium oxide, molybdenum oxide, niobium pentoxide, rare earth oxides, silicon dioxide, silicon monoxide, strontium oxide, strontium titanate, tantalum pentoxide, tin oxide, indium oxide, indium tin oxide, lanthanum aluminate, lanthanum oxide, lead titanate, lead zirconate, lead zirconate-titanate, titanium aluminide, lithium niobate, titanium oxide, tungsten oxide, yttrium oxide, zinc oxide, zirconium oxide, bismuth telluride, cadmium selenide, cadmium telluride, lead selenide, lead sulfide, lead telluride, molybdenum selenide, molybdenum sulfide, zinc selenide, zinc sulfide, zinc telluride and/or combinations thereof.
Thus, specific embodiments and applications of methods of manufacturing PVD targets and related apparatus have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the disclosure and claims herein. Moreover, in interpreting the disclosure and claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.
