Chemistry: electrical and wave energy – Apparatus – Coating – forming or etching by sputtering
Reexamination Certificate
2001-07-09
2002-09-17
McDonald, Rodney G. (Department: 1753)
Chemistry: electrical and wave energy
Apparatus
Coating, forming or etching by sputtering
C204S298130, C228S193000, C228S231000, C148S415000, C148S535000, C148S536000, C148S527000, C428S651000, C428S657000, C428S655000, C428S660000, C428S661000, C428S665000, C428S674000
Reexamination Certificate
active
06451185
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a sputtering target assembly having a precipitation hardened backing plate diffusion bonded to a sputtering target.
There has been growing interest in sputtering target assemblies with increasingly thin sputtering targets to reduce costs and, in some cases, accommodate the sputtering target assembly in certain sputtering chambers. In such applications, sputtering target assemblies of less than about one inch total thickness may be required. However, with such sputtering target assemblies, the strength of the backing plate may be exceeded under the conditions encountered in the sputtering chamber, which may include high water pressure on one side for cooling and high vacuum on the other side during the sputtering process. Thermal cycling and pressure resulting from circulating coolant exerted upon the backside of the target assembly with simultaneous vacuum conditions on the front face of the target can result in elastic and plastic deformation of the target backing plate assembly.
Although sputtering target assemblies may be made by solder bonding backing plates of various materials to a target, solder bonding has the disadvantage of not being able to withstand high power sputtering applications. Thus, diffusion bonded sputtering target assemblies are preferred.
The present invention provides a method of making a sputtering target assembly with a high strength backing plate diffusion bonded to a sputtering target that can withstand the stresses and strains typically encountered in sputtering chambers.
SUMMARY OF THE INVENTION
According to the invention there is provided a method of making a heat treated sputtering target assembly that comprises providing a sputtering target and a heat treatable, precipitation hardenable backing plate diffusion bonded to the sputtering target wherein the diffusion bonded sputtering target assembly is heat treated to precipitation harden the backing plate without delaminating or degrading the diffusion bond between target and backing plate. The method comprises precipitation hardening the backing plate by heat treatment that includes quenching the diffusion bonded sputtering target assembly by the process includes heating, working, and quenching and the quenching is performed after diffusion bonding by immersing the sputtering target assembly in a quenchant to immerse the backing plate without submerging the sputtering target. The sputtering target assembly may be subjected to a plurality of precipitation hardening treatments that include heating and partial-immersion quenching, as described, to provide a desired temper in the backing plate. In a preferred embodiment, the backing plate comprises a heat treatable aluminum alloy of the 2000, 6000 or 7000 series and the sputtering target comprises aluminum, titanium, or nickel, titanium-tungsten, tungsten, cobalt and tantalum and alloys thereof. The sputtering target assembly of the invention comprises a precipitation hardened backing plate diffusion bonded to a sputtering target.
REFERENCES:
patent: 4194672 (1980-03-01), Uto et al.
patent: 4468313 (1984-08-01), Okumura et al.
patent: 4610774 (1986-09-01), Sakata et al.
patent: 4732312 (1988-03-01), Kennedy et al.
patent: 4752335 (1988-06-01), Korb
patent: 4820397 (1989-04-01), Fielder et al.
patent: 4826584 (1989-05-01), dos Santos Pereiro Ribeiro
patent: 4838935 (1989-06-01), Dunlop et al.
patent: 4889772 (1989-12-01), Bergmann et al.
patent: 4961831 (1990-10-01), Bergmann et al.
patent: 4961832 (1990-10-01), Shagun et al.
patent: 4963239 (1990-10-01), Shimamura et al.
patent: 4963240 (1990-10-01), Fukasawa et al.
patent: 4964962 (1990-10-01), Nobutani et al.
patent: 4964968 (1990-10-01), Arita
patent: 4964969 (1990-10-01), Kusakabe et al.
patent: 4966676 (1990-10-01), Fukasawa et al.
patent: 4966677 (1990-10-01), Aichert et al.
patent: 4971674 (1990-11-01), Hata
patent: 5032468 (1991-07-01), Dumont et al.
patent: 5066381 (1991-11-01), Ohta et al.
patent: 5230459 (1993-07-01), Mueller et al.
patent: 5342496 (1994-08-01), Stellrecht
patent: 5397050 (1995-03-01), Mueller
patent: 5487822 (1996-01-01), Demaray et al.
patent: 5693203 (1997-12-01), Ohhashi et al.
patent: 6274015 (2001-08-01), Beier et al.
patent: 0370211 (1990-05-01), None
patent: 0590904 (1994-04-01), None
patent: 63-20154 (1988-01-01), None
patent: 63-157102 (1988-06-01), None
patent: 63-270459 (1988-08-01), None
patent: 01-47863 (1989-02-01), None
patent: 1283367 (1989-11-01), None
patent: 1301855 (1989-12-01), None
patent: 6158296 (1994-06-01), None
patent: 7278804 (1995-02-01), None
patent: 98-26107 (1998-06-01), None
John Dunlop et al., “Effects of Ti-W Target Processing Methods on Defect Generation During VLSI Device Fabrication”, American Vacuum Society 37thAnnual Symposium and Topical Conferences, Toronto, Canada, Oct. 8-12, 1990, 17 pgs.
ASM Handbook, vol. 2, Properties and Selection, pp. 15-27, 223, 234, 235, ASM International, 1990.
Advanced Materials and Processes, vol. 156, No. 6, Dec. 1999, p. 100.
Beier Anthony F.
Kardokus Janine K.
Strothers Susan D.
McDonald Rodney G.
Wells St. John P. S.
LandOfFree
Diffusion bonded sputtering target assembly with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Diffusion bonded sputtering target assembly with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diffusion bonded sputtering target assembly with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2910764