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`US 20010047838Al
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`(19)United States
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`(12)Patent Application Publication
`US 2001/0047838 Al
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`(10)Pub. No.:
`(43) Pub. Date: Dec. 6, 2001
`
`Segal et al.
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`(54)METHODS OF FORMING
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`ALUMINUM-COMPRISING PHYSIC AL
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`VAPOR DEPOSITION TARGETS;
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`SPUTTERED FILMS; AND TARGET
`CONSTRUCTIONS
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`(52)U.S. Cl. ............................ 148/437; 72/256; 148/438;
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`148/439; 148/440
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`(57)
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`ABSTRACT
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`Correspondence Address:
`
`Shannon Morris
`
`
`Honeywell International Inc.
`Box 2245
`101 Columbia Road
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`Morristown, NJ 07962 (US)
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`(21)Appl. No.:
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`09/783,377
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`(22)Filed:
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`Feb. 13,2001
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`(76)Inventors: Vladimir M. Segal, Veradale, WA
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`The invention includes a method of forming an aluminum
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`comprising physical vapor deposition target. An aluminum
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`(US); Jianxing Li, Spokane, WA (US);
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`comprising mass is deformed by equal channel angular
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`Frank Alford, Veradale, WA (US);
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`extrusion. The mass is at least 99.99% aluminum and further
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`Stephane Ferrasse, Veradale, WA (US)
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`comprises less than or equal to about 1,000 ppm of one or
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`more dopant materials comprising elements selected from
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`the group consisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd,
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`Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir,
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`La, Lu, Mg, Mn, Mo, N, Nb, Nd, Ni, 0, Os, P, Pb, Pd, Pm,
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`Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr,
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`Ta, Tb, Te, Ti, Tl, Tm, V, W, Y, Yb, Zn and Zr. After the
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`aluminum comprising mass is deformed, the mass is shaped
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`into at least a portion of a sputtering target. The invention
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`also encompasses a physical vapor deposition target con
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`sisting essentially of aluminum and less than or equal to
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`1,000 ppm of one or more dopant materials comprising
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`elements selected from the group consisting of Ac, Ag, As,
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`B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga,
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`(63)Non provisional of provisional application No.
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`Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb, Nd, Ni,
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`60/193,354, filed on Mar. 28, 2000.
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`0, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb,
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`Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Ti, Tm, V, W, Y, Yb,
`Zn and Zr. Additionally, the invention encompasses thin
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`(51)Int. CI.7 ........................... C22C 21/00; B21C 23/00
`films.
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`Related U.S. Application Data
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`Publication Classification
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`CAST INGOT
`(1)
`t
`(2)PRELIMINARY
`THERMOMECHANICAL
`PROCESSING
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`t
`DEFORM MASS
`(3)
`BY £CA£
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`t
`{ 4) SHAPE MASS INTO
`AT LEAST A PORTION OF
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`A SPUTTERING TARGET
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`t
`(5)MOUNT THE
`SHAPED MASS TO
`A BACKING PLATE
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`Samsung Electronics Co., Ltd. v. Demaray LLC
`Samsung Electronic's Exhibit 1069
`Exhibit 1069, Page 1
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`Patent Application Publication
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`Dec. 6, 2001 Sheet 1 of 9
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`US 2001/0047838 Al
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`FF ayo
`FuURGITR FOIRT
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`Ex. 1069, Page 2
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`Patent Application Publication
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`Dec. 6, 2001 Sheet 2 of 9
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`US 2001/0047838 A1
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`Ez my AD
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`FPiRITHR FORT
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`300
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`GRAIN SIZE
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`(microns)
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`100
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`80 9095
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`99
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`ROLLING REDUCTION (%)
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`HE a oF aff
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`FURGIT Fit 7
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`Ex. 1069, Page 3
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`Patent Application Publication
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`Dec. 6,2001 Sheet 3 of 9
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`GRAIN SIZE
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`60
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`80 9095
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`ROLLING REDUCTION (%)
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`Ear ry a
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`100
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`FRILIPR FIR T
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`FrRGIMF FLIRT
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`Ex. 1069, Page 4
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`Patent Application Publication
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`Dec. 6, 2001 Sheet 4 of 9
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`US 2001/0047838 A1
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`LE iz. ay
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`FURGIR FORT
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`(1) CAST INGOT
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`(2) PRELIMINARY
`THERMOMECHANICAL
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`PROCESSING
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`(3) DEFORM MASS
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`BY ECAE
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`(4) SHAPE MASS INTO
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`AT LEAST A PORTION OF
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`A SPUTTERING TARGET
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`(5) MOUNT THE
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`SHAPED MASS TO
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`A BACKING PLATE
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`LE az ay
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`Ex. 1069, Page 5
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`Ex. 1069, Page 5
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`Patent Application Publication
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`Dec. 6,2001 Sheet 5 of 9
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`Ex. 1069, Page 6
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`Ex. 1069, Page 6
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`300
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`ECAE (passes)
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`EE a wy Ul
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`6
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`100
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`ECAE (passes)
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`Enz wy Aa
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`Ex. 1069, Page 7
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`Patent Application Publication
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`US 2001/0047838 Al
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`Ex. 1069, Page 8
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`Patent Application Publication
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`Dec. 6, 2001 Sheet 8 of 9
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`Patent Application Publication
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`Dec. 6,2001 Sheet 9 of 9
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`eo 190
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`Ex. 1069, Page 10
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`Ex. 1069, Page 10
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`US 2001/0047838 Al
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`Dec.6, 2001
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`
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`METHODS OF FORMING
`
`
`ALUMINUM-COMPRISING PHYSICAL VAPOR
`
`
`
`
`
`
`
`DEPOSITION TARGETS; SPUTTERED FILMS;
`AND TARGET CONSTRUCTIONS
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`
`
`
`RELATED APPLICATION DATA
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`[0001] This application claimspriority to U.S. provisional
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`application Ser. No. 60/193,354, which was filed Mar. 28,
`2000.
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`TECHNICAL FIELD
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`[0002] The invention pertains to methods of forming alu-
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`minum-comprising physical vapor deposition targets, and to
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`target constructions. In particular applications, the invention
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`pertains to methodsofutilizing equal channel angular extru-
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`sion (ECAE) to deform an aluminum-comprising mass in
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`forming a physical vapor deposition (PVD)target for use in
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`the manufacture of flat panel displays (FPDs), such as, for
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`example, liquid crystal displays (LCDs).
`BACKGROUND OF THE INVENTION
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`[0003] PVD is a technology by which thin metallic and/or
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`ceramic layers can be sputter-deposited onto a substrate.
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`Sputtered materials come from a target, which serves gen-
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`erally as a cathode in a standard radio-frequency (RF) and/or
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`direct current (DC) sputtering apparatus. For example, PVD
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`is widely used in the semiconductor industry to produce
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`integrated circuits.
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`[0004] A relatively new application for sputtering tech-
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`nologiesis fabrication of FPDs, such as, for example, LCDs.
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`The LCD market has experienced rapid growth. This trend
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`may accelerate in the next few years due to the diversified
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`applications of LCDsin, for example the markets of laptop
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`personal computers (PCs), PC monitors, mobile devices,
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`cellular phones and LCDtelevisions.
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`[0005] Aluminum can be a particularly useful metal in
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`forming LCDs, and it accordingly can be desired to form
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`aluminum-comprising physical vapor deposition targets.
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`The targets can contain a small content (less than or equalto
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`about 100 parts per million (ppm)) of doping elements. The
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`aluminum, with or without small additions of dopants, is
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`generally desired to be deposited to form a layer of about
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`300 nm which constitutes the reflecting electrode of LCD
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`devices. Several factors are important in sputter deposition
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`of a uniform layer of aluminum having desired properties for
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`LCD devices. Such factors including: sputtering rate; thin
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`film uniformity; and microstructure.
`Improvements are
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`desired in the metallurgy of LCD aluminum targets to
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`improve the above-discussed factors.
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`LCDtargets are quite large in size, a typical size
`[0006]
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`being 860x910x19 mm%, and are expected to becomebigger
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`in the future. Such massive dimensionspresent challenges to
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`the developmentof tooling and processing for fabrication of
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`suitable aluminum-comprising targets.
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`[0007] Various works demonstrate that three fundamental
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`factors of a target can influence sputtering performance. The
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`first factor is the grain size of the material, i.e. the smallest
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`constitutive part of a polycrystalline metal possessing a
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`continuouscrystal lattice. Grain size ranges are usually from
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`several millimeters to a few tenths of microns; depending on
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`metal nature, composition, and processing history.
`is
`It
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`finer and more homogeneous grain sizes
`believed that
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`improvethin film uniformity, sputtering yield and deposition
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`rate, while reducing arcing. The second factor is target
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`texture. The continuous crystal
`lattice of each grain is
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`oriented in a specific way relative to the plane of target
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`surface. The sum of all the particular grain orientations
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`defines the overall target orientation. When no particular
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`target orientation dominates, the texture is considered to be
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`a randomstructure. Like grain size, crystallographic texture
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`can strongly depend on the preliminary thermomechanical
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`treatment, as well as on the nature and composition of a
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`given metal. Crystallographic textures can influence thin
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`film uniformity and sputtering rate. The third factor is the
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`size and distribution of structural components, such as
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`second phase precipitates and particles, and casting defects
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`(such as, for example, voids or pores). These structural
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`components are usually not desired and can be sources for
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`arcing as well as contamination of thin films.
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`[0008]
`In order to improve the manufacture of LCD tar-
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`gets it would be desirable to accomplish one or more of the
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`followingrelative to aluminum-based target materials: (1) to
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`achieve predominate and uniform grain sizes within the
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`target materials of less than 100 ym; (2) to have the target
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`materials consist of (or consist essentially of) high purity
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`aluminum (i.e. aluminum ofat least 99.99% (4N)purity, and
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`preferably at least 99.999% (5N) purity, with the percent-
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`ages being atomic percentages); (3) to keep oxygen content
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`within the target materials low; and (4) to achieve large
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`target sizes utilizing the target materials.
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`[0009] The thermomechanical processes (TMP) used tra-
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`ditionally to fabricate LCD targets can generally only
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`achieve grain sizes larger than 200 wm for 5N Al with or
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`without dopants. Such TMPprocesses involve the different
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`steps of casting, heat
`treatment,
`forming by rolling or
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`forging, annealing and final fabrication of the LCDtarget.
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`Because forging and rolling operations change the shape of
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`billets by reducing their thickness, practically attainable
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`strains in today’s TMP processes are restricted. Further,
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`rolling and forging operations generally produce non-uni-
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`form straining throughout a billet.
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`[0010] The optimal method for refining the structure of
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`high purity aluminum alloys
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`for example,
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`99.9995% aluminum) would be intensive plastic deforma-
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`tion sufficient to initiate and complete self-recrystallization
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`at room temperature immediately after cold working.
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`{0011] High purity aluminum is typically provided as a
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`cast ingot with coarse dendrite structures (FIG.1 illustrates
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`a typical structure of as-cast 99.9995% aluminum). Forging
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`and/or rolling operations are utilized to deform the cast
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`ingots into target blanks. Flat panel display target blanks are
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`optimally to be in the form of large thin plates. The total
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`strains which can be obtained for any combination of forging
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`and/or
`rolling operations can be expressed as e=(1-h/
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`H,)*100%; where H, is an ingot length, and h is a target
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`blank thickness. Calculations show that possible thickness
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`reductions for conventional processes range from about 85%
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`to about 92%, depending on target blank size to thickness
`ratio. The thickness reduction defines the strain induced in a
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`material. Higher thickness reductions indicate more strain,
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`and accordingly can indicate smaller grain sizes. The con-
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`ventional reductions of 85% to 92% can provide static
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`recrystallization of high purity aluminum (for instance,
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`Ex. 1069, Page 11
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`Ex. 1069, Page 11
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`US 2001/0047838 Al
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`Dec.6, 2001
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`aluminum having a purity of 99.9995% or greater) but they
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`are not sufficient
`to develop the fine and uniform grain
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`structure desired for flat panel display target materials. For
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`example, an average grain size after 95% rolling reduction
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`is about 150 microns(such is shown in FIG.2). Such grain
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`size is larger than that which would optimally be desired for
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`a flat panel display. Further,
`the structures achieved by
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`conventional processes are not stable. Specifically, if the
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`structures are heated to a temperature of 150° C. or greater
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`(which is a typical temperature for sputtering operations),
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`the average grain size of the structures can grow to 280
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`microns or more (see FIG. 3). Such behavior occurs even
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`after intensive forging or rolling.
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`{0012] FIG. 4 summarizes results obtained for a priorart
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`high purity aluminum material. Specifically, FIG. 4 shows
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`a curve 10 comprising a relationship between a percentage
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`of rolling reduction and grain size (in microns). A solid part
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`of curve 10 shows an effect of rolling reduction on a
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`99.9995% aluminum material which is self-recrystallized at
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`room temperature. As can be seen, even a high rolling
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`reduction of 95% results in an average grain size of about
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`160 microns (point 12), which is a relatively coarse and
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`non-uniform structure. Annealing at 150° C. for 1 hour
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`significantly increases the grain size to 270 microns (point
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`14). An increase of reduction to 99% can reduce the grain
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`size to 110 microns(point 16 of FIG.4), but heating to 150°
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`C. for 1 hour increases the average grain size to 170 microns
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`(point 18 of FIG. 4).
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`[0013] Attempts have been madeto stabilize recrystallized
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`high purity aluminum structures by adding low amounts of
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`different doping elements (such as silicon,
`titanium and
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`scandium) to the materials. A difficulty that occurs when the
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`doping elements are incorporated is that full self-recrystal-
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`lization can generally not be obtained for an entirety of the
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`material, and instead partial recrystallization is observed
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`along grain boundaries andtriple joints. For example, the
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`structure of a material comprising 99.9995% aluminum with
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`30 ppm Si doping is only partly recrystallized after rolling
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`with a high reduction of 95% (see FIG.6) in contrast to the
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`fully recrystallized structure formed after similar rolling of
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`a pure material (see FIG. 2). Accordingly, additional anneal-
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`ing of the rolled material at a temperature of 150° C. for
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`about 1 houris typically desired to obtain a fully recrystal-
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`lized doped structure. Such results in coarse and non-
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`uniform grains (see FIG.7).
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`[0014] FIG. 5 illustrates data obtained for 99.9995%
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`aluminum with a 30 ppm silicon dopant. The curve 20 of
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`FIG. 5 conforms to experimental data of 99.9995% alumi-
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`num with 30 ppm silicon after rolling with different reduc-
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`tions. A dashed part of the curve 20 correspondsto partial
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`self-recrystallization after rolling, while a solid part of the
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`curve corresponds to full self-recrystallization. The full
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`self-recrystallization is attained after intensive reductions of
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`more than 97%, which are practically not available in
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`commercial target fabrication processes. The point 22 shows
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`the average grain size achieved for the as-deformed material
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`as being about 250 microns, and the point 24 showsthat the
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`grain size reduces to about 180 micronsafter the material is
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`annealed at 150° C. for 1 hour. The points 22 and 24 of FIG.
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`5 correspond to the structures of FIGS. 6 and 7.
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`[0015] For the reasons discussed above, conventional
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`metal-treatment procedures are incapable of developing the
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`fine grain size and stable microstructures desired in high
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`purity aluminum target materials for utilization in flat panel
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`display technologies. For instance, a difficulty exists in that
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`conventional deformation techniques are not generally
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`capable of forming thermally stable grain sizes of less than
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`150 microns for both doped and non-doped conditions of
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`high purity metals. Also, particular processing environments
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`can create further problems associated with conventional
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`metal-treatment processes. Specifically, there is a motivation
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`to use cold deformation as much as possible to refine
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`structure, which can remove advantagesof hot processing of
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`cast materials for healing pores and voids, and for eliminat-
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`ing other casting defects. Such defects are difficult, if not
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`impossible, to remove by cold deformation, and some of
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`them can even be enlarged during cold deformation. Accord-
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`ingly, it would be desirable to develop methodologies in
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`which casting defects can be removed, and yet which
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`achieve desired small grain sizes and stable microstructures.
`SUMMARYOF THE INVENTION
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`[0016]
`In one aspect, the invention includes a method of
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`forming an aluminum-comprising physical vapor deposition
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`target. An aluminum-comprising massis deformed by equal
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`channel angular extrusion, with the mass being at
`least
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`99.99% aluminum and further comprising less than or equal
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`to about 1,000 ppm of one or more dopant materials com-
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`prising elements selected from the group consisting of Ac,
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`Ag,As, B, Ba, Be, Bi, C, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu,
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`Fe, Ga, Gd, Ge, Hf, Ho, In, Ir, La, Lu, Mg, Mn, Mo, N, Nb,
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`Nd,Ni, 0, Os, P, Pb, Pd, Pm, Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru,
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`S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Te, Ti, Tl, Tm, V, W,
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`Y, Yb, Zn and Zr. After the aluminum-comprising mass is
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`deformed, the mass is shaped into at least a portion of a
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`sputtering target. The sputtering target can ultimately be
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`formedto be either a monolithic or mosaic sputtering target.
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`[0017]
`In another aspect,
`the invention encompasses a
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`method of forming an aluminum-comprising physical vapor
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`deposition target which is suitable for sputtering aluminum-
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`comprising material to form an LCD device. An aluminum-
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`comprising mass is deformed by equal channel angular
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`extrusion. After the mass is deformed, it is shaped into at
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`least a portion of a physical vapor deposition target. The
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`physical vapor deposition target has an average grain size of
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`less than or equal to 45 microns.
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`[0018]
`In yet another aspect, the invention encompasses a
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`physical vapor deposition target consisting essentially of
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`aluminum andless than or equal to 1,000 ppm of one or
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`more dopant materials comprising elements selected from
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`the group consisting of Ac, Ag, As, B, Ba, Be, Bi, C, Ca, Cd,
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`Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, In, Ir,
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`La, Lu, Mg, Mn, Mo, N,Nb, Nd, Ni, 0, Os, P, Pb, Pd, Pm,
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`Po, Pr, Pt, Pu, Ra, Rf, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr,
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`Ta, Tb, Te, Ti, Tl, Tm, V, W, Y, Yb, Zn and Zr. The physical
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`vapor deposition target has an average grain size of less than
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`or equal to 100 microns.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
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`the
`invention are
`[0019] Preferred embodiments of
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`described below with reference to the following accompa-
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`nying drawings.
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`[0020] FIG. 1 is an optical micrograph of a cast structure
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`of 99.9995% aluminum (magnified 50 times).
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`Ex. 1069, Page 12
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`Ex. 1069, Page 12
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`

`

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`US 2001/0047838 Al
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`Dec.6, 2001
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`[0021] FIG. 2 is an optical micrograph of 99.9995%
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`aluminum showinga self-recrystallized structure after 95%
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`cold rolling reduction (magnified 50 times).
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`[0022] FIG. 3 is an optical micrograph of 99.9995%
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`aluminum illustrating a structure achieved after 95% cold
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`rolling reduction and annealing at 150° C.
`for 1 hour
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`(magnified 50 times).
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`[0023] FIG. 4 is a graph illustrating an effect of prior art
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`rolling reduction processes on grain size of 99.9995% alu-
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`minum whichis self-recrystallized at room temperature.
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`[0024] FIG. 5 is a graphillustrating the effect of prior art
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`rolling reduction on grain size of a material comprising
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`99.9995% aluminum with 30 ppm Si, with such material
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`being partly self-recrystallized at room temperature.
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`[0025] FIG. 6 is an optical micrograph of 99.9995%
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`aluminum plus 30 ppm Si after 90% cold rolling reduction
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`(magnified 50 times).
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`[0026] FIG. 7 is an optical micrograph of 99.9995%
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`aluminum plus 30 ppm Si after 90% cold rolling reduction
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`and annealing at 150° C. for 1 hour (magnified 50 times).
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`[0027] FIG. 8 shows a flow chart diagram of a method
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`encompassed by the present invention.
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`FIG.9 is an optical micrograph showingthe struc-
`[0028]
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`ture of 99.9995% aluminum after 2 passes through an equal
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`channel angular extrusion (ECAE) device (magnified 50
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`times).
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`[0029] FIG. 10 is an optical micrograph of 99.9995%
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`aluminum after 6 passes through an ECAE device (magni-
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`fied 50 times).
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`[0030] FIG. 11 is a graphillustrating the effect of ECAE
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`on grain size of 99.9995% aluminum whichis self-recrys-
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`tallized at room temperature.
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`[0031] FIG. 12 is a graphillustrating the effect of ECAE
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`passes on grain size of a material comprising 99.9995%
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`aluminum and 30 ppm Si. The graph illustrates the grain size
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`after self-recrystallization of the material at room tempera-
`ture.
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`[0032] FIG. 13 is an optical micrograph showing the
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`structure of a material comprising 99.9995% aluminum and
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`30 ppm Si after 6 passes through an ECAE device (magni-
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`fied 100 times).
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`[0033] FIG. 14 is an optical micrograph showing the
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`structure of a material comprising 99.9995% aluminum and
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`30 ppm Si after 6 passes through an ECAE device, 85% cold
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`rolling reduction, and annealing at 150° C. for 16 hours
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`(magnified 100 times).
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`[0034] FIGS. 15A and 15B showoptical micrographs of
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`a material comprising aluminum and 10 ppm Scafter 6
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`ECAE passes via route D (ie., a route corresponding to
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`billet rotation of 90° into a same direction after each pass
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`through an ECAE device). FIG. 15A shows the material in
`the as-deformed state and FIG. 15B shows material after
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`85% rolling reduction in thickness.
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`[0035] FIG. 16 is a diagrammatic top-view ofa tiled target
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`assembly composed of nine billets.
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`[0036] FIG. 17 is a diagrammatic cross-sectional side-
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`view of the target assembly of FIG. 16 shownalongthe line
`17-17.
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`DETAILED DESCRIPTION OF THE
`
`
`PREFERRED EMBODIMENTS
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`[0037] A deformation technique known as equal channel
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`angular extrusion (ECAE) is used with advantage for the
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`manufacture of physical vapor deposition targets, and in
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`particular aspects of the inventionis utilized for the first time
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`in the manufacture of FPD and LCD targets. The ECAE
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`technique was developed by V. M. Segal, and is described in
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`US. Pat. Nos. 5,400,633; 5,513,512; 5,600,989; and 5,590,
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`390. The disclosure of the aforementioned patents is
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`expressly incorporated herein by reference.
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`[0038] The general principle of ECAE is to utilize two
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`intersecting channels of approximately identical cross-sec-
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`tion and extrude a billet through the channels to induce
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`deformations within the billet. The intersecting channels are
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`preferably exactly identical in cross-section to the extent that
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`“exactly identical” can be measured and fabricated into an
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`ECAE apparatus. However, the term “approximately iden-
`tical” is utilized herein to indicate that the cross-sections
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`may beclose to exactly identical, instead of exactly identi-
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`cal, due to, for example, limitations in fabrication technol-
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`ogy utilized to form the intersecting channels.
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`[0039] An ECAE apparatus inducesplastic deformation in
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`a material passed through the apparatus. Plastic deformation
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`is realized by simple shear, layer after layer, in a thin zone
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`at a crossing plane of the intersecting channels of the
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`apparatus. A useful feature of ECAE is that the billet shape
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`and dimensions remain substantially unchanged during pro-
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`cessing (with term “substantially unchanged”indicating that
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`the dimensions remain unchanged to the extent that the
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`intersecting channels have exactly identical cross-sections,
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`and further indicating that the channels may not have exactly
`
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`identical cross-sections).
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`[0040] The ECAE technique can have numerous advan-
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`tages. Such advantages can include: strictly uniform and
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`homogeneous straining; high deformation per pass; high
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`accumulated strains achieved with multiple passes; different
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`deformation routes, (i.e., changing of billet orientation at
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`each pass of multiple passes can enable creation of various
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`textures and microstructures); and low load and pressure.
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`[0041] ECAE can enable a decrease in the grain size of
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`high purity aluminum and aluminum alloys used for the
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`manufacture of LCDsbyatleast a factor of three compared
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`to conventional practices.
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`[0042] Various aspects of the present invention are sig-
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`nificantly different
`from previous ECAE applications.
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`Amongthe differences is that the present invention encom-
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`passes utilization of ECAE to deform high purity materials
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`(such as, for example, aluminum having a purity of greater
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`than 99.9995% as desired for FPD targets), in contrast to the
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`metals and alloys that have previously been treated by
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`ECAE. High purity metals are typically not heat treatable,
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`and ordinary processing steps like homogenizing, solution-
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`izing and aging can be difficult, if not impossible, to satis-
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`factorily apply with high purity metals. Further, the addition
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`of low concentrations of dopants (i.e., the addition of less
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`than 100 ppm of dopants) doesn’t eliminate the difficulties
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`Ex. 1069, Page 13
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`Ex. 1069, Page 13
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`

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`US 2001/0047838 Al
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`Dec.6, 2001
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`not toxic, refractory or precious metals, and further possess
`encountered in working with high purity metals. However,
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`relatively high melting temperatures. The second type of
`the present invention recognizes that a method for control-
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`materials include various elements selected from the Group
`ling structure of single-phase high purity materials is a
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`IIA elements;
`the Group IIIB elements;
`the Group IVB
`thermo-mechanical treatment by deformation, annealing and
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`elements;
`the Group VIB elements;
`the Group VIII ele-
`recrystallization. Also, as high purity metals are generally
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`ments; the Group IIIA elements; the Group VA elements; the
`not stable and cannotbe refined by dynamicrecrystallization
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`Group VIA elements, and the Rare Earth elements (i.e., the
`in the same manneras alloys, the present invention recog-
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`lanthanides).
`nizes that static recrystallization can be a more appropriate
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`methodology for annealing of high purity metals than
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`[0047] The dopant materials can be in the form of pre-
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`dynamic recrystallization. When utilizing static recrystalli-
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`cipitates or solid solutions within the aluminum-material
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`zation annealing of materials, it is preferred that the static
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`matrix. Preferably, the target is composed of aluminum with
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`recrystallization be conducted at
`the lowest
`temperature
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`purity greater than or equal to 99.99% (4N), and with one or
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`which will provide a fine grain size. If strain is increased to
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`more dopant materials comprising elements selected from
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`a high level within a material, such can reduceastatic
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`the group consisting of Si, Sc, Ti, and Hf.
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`recrystallization temperature, with high strains leading to
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`materials which can be statically recrystallized at room
`[0048] The present invention can provide a physical vapor
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`temperature. Thus,