US0078l1421B2
`
`(12) United States Patent
`Chistyakov
`
`(10) Patent No.:
`
`(45) Date of Patent:
`
`US 7,811,421 B2
`*Oct.12, 2010
`
`(54) HIGH DEPOSITION RATE SPUTTERING
`
`(75)
`
`Inventor: Roman Chistyakov, Andover. MA (US)
`
`(73) Assignee: Zond, Inc., Mansfield, MA (US)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 896 days.
`
`This patent is subject to a terminal dis—
`claimer.
`
`(21) Appl.No.: 11/183,463
`
`(22)
`
`Filed:
`
`Jul. 18, 2005
`
`(65)
`
`Prior Publication Data
`US 2005/0252763 A1
`Nov. 17, 2005
`
`Related U.S. Application Data
`
`(63) Continuation of application No. 11/091,814. filed on
`Mar. 28, 2005, now abandoned.
`
`(51)
`
`Int. Cl.
`(2006.01)
`C23C 14/35
`(52) U.S. Cl.
`......................... .. 204/192.12: 204/298.08’.
`204/298.06
`
`(58) Field of Classification Search .......... .. 204/192.12.
`204/298.06. 298.08
`
`See application file for complete search history.
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4,588,490 A
`5.015.493 A
`5,083,061 A
`5,286,360 A
`5.576.939 A
`5.718.813 A
`5,728,278 A
`
`5/1986 Cuomo et al.
`5/1991 Gnten
`1/1992 Koshiishi et :11.
`2/1994 Szczyrbowski et al.
`l 1/1996 Drummond
`Z/1998 Dmmmond et .11.
`3/I998 Okamura ct al.
`
`5.733.418 A
`6.024.844 A
`6.057.244 A
`6.083.361 A
`6,086,730 A
`6.217.717 B1
`
`3/1998 l'le1'shcovitch et al.
`2/"2000 Drummend et al.
`5/2000 I-Iausmann et al.
`7/2000 Kobayashi et 211.
`7/2000 l.iu ct :11.
`4/2001 Dnnmnond et al.
`
`(Continued)
`FOREIGN PATENT DOCUMENTS
`
`DE
`
`3210351 Al
`
`9/1983
`
`(Continued)
`OTHER PUBLICATIONS
`
`Booth, et 211.. The Transition From Symmetric To Asymmetric Dis»
`charges In Pulsed 13.56 Ml-17. (‘apacitively Coupled Plasmas. .1. Appl.
`Phys. Jul. 15. 1997. pp. 552-560. vol. t<?(2).A1nerictm Institute of
`Physics.
`
`(Continued)
`
`Primary l?.mmiz1er—Rodney G McDonald
`(74)
`/1/Ior/ray. Age/71, or Firm Kurt Rauschenbach:
`Rauschenbztch Patent Law Group. 1.1.1’
`
`(57)
`
`ABSTRACT
`
`Methods and apparatus for high-deposition sputtering are
`described. A sputtering source includes an anode and a cath-
`ode assembly that is positioned adjacent to the anode. The
`cathode assembly includes a sputtering target. An ionization
`source generates a weakly-ionized plasma proximate to the
`anode and the cathode assembly. A power supply produces an
`electric field between the anode and the cathode assembly
`that creates a strongly—ionized plasma from the weakly—ion-
`ized plasma. The strongly—ionized plasma includes a first
`plurality of ions that impact the sputtering target to generate
`sufficient thermal energy in the sputtering target to cause a
`sputtering yield 01' the sputtering target to be non—linez-trly
`related to a temperature ofthe sputtering target.
`
`48 Claims. 13 Drawing Sheets
`
`fE'fi'A‘rcHi
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`EX 1201
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`

`
`US 7,811,421 B2
`Page 2
`
`U.S. PATENT l)OCUMEN'l‘S
`
`204/298.19
`
`5/2001 Kahnetal.
`6.238.537 Bl
`6/2001 Fu et al.
`6,251,242 B1 ""
`10/2001 Kouznetsov
`6.296.742 Bl
`12/2001
`Petr‘
`6,327,163 B1
`3/2002 Kobayashi et al.
`6,361,667 B1
`7/2002 Wang et al.
`6.413.382 Bl
`7/2002 Chiang et al.
`6,413,383 B1
`8/2002 Gopalraja et al.
`6,436.251 B2
`2/2003 Driimmond ct al.
`6,521,099 B1
`10/2004 Christie
`6.808,607 B2
`5/2005 Chistyakov .......... .. 204/192.12
`6,896,773 B2 *
`8/2006 Chistyakov .......... .. 315/111.21
`7,095,179 B2 *
`7,147,759 B2* 12/2006 Chistyakov .......... .. 204/192.12
`2002/0033480 A1
`3/ 2002 Kawamata et al.
`2002/0114897 A1
`8/2002 Sumiya et al.
`5/2005 Kouznetsov
`2005/0092596 A1
`2005/0103620 A1
`5/200 5 Chistyakov
`5/2005 Ehiasarian et al.
`2005/0109607 A1
`2005/0184669 A1
`8/2005 Chistyakov
`2009/0263966 A1
`10/2009 Weichan et al.
`
`FOREIGN PATENT DOCUMENTS
`
`EP
`GB
`GB
`JP
`JP
`JP
`JP
`JP
`.11’
`RU
`RU
`RU
`W0
`W0
`W0
`
`0788139 Al
`1339910
`2401116 A
`57194254
`62-216637
`08-067981
`08—293470
`2004-01097‘)
`2004 010979 A
`2 029 411 C1
`2 058 429 ('1
`2058429
`WO 98/40532
`W001/98553 A1
`W0 02/103078
`
`*
`
`8/1997
`12/1973
`3/2004
`11/1982
`9/1987
`3/ 1996
`11/1996
`1/"2004
`l/2004
`5/1995
`411996
`4/"1996
`9/1998
`12/2001
`* 12/2002
`
`OTHER PUBLICATIONS
`
`Bunshah, et al.. Deposition Technologies For Films And Coatings,
`Materials Science Series, pp. 176-183, Noyes Publications. Park
`Ridge, New Jersey.
`Daugherty. et al.. Attachment—Dominated Electron-Beam-Ionized
`Discharges, Applied Science I_.ctters. May 15, 1976. vol. 28, No. 10,
`American Institute of Physics.
`Goto. et al.. Dual Excitation Reactive Ion Etcher For Low Energy
`Plasma Processing, J. Vac. Sci. Technol. A.. Sep./Oct. 1992. pp.
`3048-3054. vol. 10, No. 5, American Vacuum Society.
`Kouznetsov, et al., A Novel Pulsed Magnetron Sputter Technique
`Utilizing Very High Target Power Densities, Surface & Coatings
`Technology, pp. 290-293. Elsevier Sciences S. A.
`Iindquist. ct al., High Selectivity Plasma Ftching OfSilicon Dioxide
`With A Dual Frequency 27/2 MHZ Capacitive RF Discharge.
`Macak. Reactive Sputter Deposition Process Ot‘A1203 And Charac-
`terization Of/\ Novel High Plasma Density Pulsed Magnetron Dis-
`charge, Linkoping Studies In ScienceAndTechnology. 1999. pp. 1-2:
`Sweden.
`Macak. et al., Ionized Sputter Deposition Using An Extremely High
`Plasma Density Pulsed Magnetron Discharge. J. Vac. Sci. Technol. A.
`Jul./Aug. 2000, pp. 1533-1537. vol. 18,
`,\lo. 4. American Vacuum
`Society.
`Mozgrin. et al., High—Current Low—Pi'essure Quasi-Stationary 1)is-
`charge In A Magnetic Field: Experimental Research. Plasma Physics
`Reports, 1995. pp. 400-409. vol. 21. No. 5. Mozgrin lieitsov
`Khodachenko.
`In Circulzu Planar
`Induced Drift Currents
`Rossnagel,
`et al..
`Magnetrons. .1. Vac. Sci. Technol. A.. Jan./Feb. 1987. pp. 88-91, vol.
`5. No. 1. American Vacuum Society.
`
`5
`
`l\'o. 10/949.427, Apr. 21. 2006. 6
`
`1 1/091.814. Jul. 14. 2008. 19
`
`.1a.n.
`
`I5, 2004. 12
`
`11
`
`S.
`
`Appl. No 10/065.739. licb. 18. 2004. 14
`
`Appl. No. 10/065739. May 20. 2004. 14
`
`Sheridan. ct al.. Electron Velocity Distribution Functioiis In A Sput-
`tering Magnetron l)ischa.rge For The EXB l)irection, .1. Vac. Sci.
`Technol. A...1ul./Aug. l998.pp. 2173-2176, vol. 16, No. 4. American
`Vactiiiin Society.
`Streinbruchel. A Simple Formula For I..ow-Energy Sputtering Yields.
`Applied Physics A.. 1985. pp. 37-42, vol. 36. Springer-Vcrlag
`Chistyakov, Iligh-Power Pulsed Magnetron Sputtering. US. Appl.
`No. 10/065.277. tiled Sep. 30. 2002.
`C'histyako\/. High-Power Pulsed Magnetically Enhanced Plasma Pi o-
`cessing. U.S. Appl. No. 10/061,551. ti1ed(")ct. 29. 2002..
`(‘histyakov. Methods And Apparatus lor Generating 1-1igh~l)ensity
`Plasma, ITS. Appl. No. 10/065629. tiled Nov 4, 2002.
`llncyclopedia()fl..ow'1‘cmperati.irc Plasma. p.
`1 19. vol. 3.
`Lncyclopedia Of Low Teinperature Plasma. p. 123. vol. 3.
`Turenko. et al., Magnetron Discharge In The Vapor 01‘ The Cathode
`Material. Soviet Technical Physics Letters. Jul. 1989. pp. 519-520.
`vol. 15. No. 7. NewYork. US.
`“Notification OfTransmit'tal Of The International Search Repon Or
`The Declaration” For PCT/US03/34226, Jun. 23. 2004. 6 pages. The
`International Searching, Authority/EPO. Rijswijk. The Netherlands.
`Notice Of Reasons For Rejection. Japanese Patent Office. Aug. 24.
`2009. 27 Pages. Japan.
`.S. Appl. No. 10/065,277.
`"O1“ficc Action” for
`pages, The L SPTO, 1. S.
`“(.)t‘fice Action” for L .S. Appl. No. 10/065.277. Aug. 30, 2004. 14
`pages. The USPTO,
`IS.
`"Ollice Action” for
`.S. Appl. No. 10/065277. May 27. 2005. 13
`pages. The I SPTO, I. S.
`“()Fficc Action” for
`.S_ Appl. No. 10/065277, Ja.n. 11. 2006. 15
`pages. The USP’ T). I S.
`“()ffice Action” for US Appl. No. 10/065277. Jul. 18. 2006. 6
`pages. Thel SPTO,
`“Otlicc Action” for US. Appl. No. 10/065.629. Oct. 7. 1,003.
`pages. The USP'"(‘>. JS.
`“(.')ffice Action” for
`pages, Tliel Sl"l().
`“O1Tice Action” for
`pages. The USP’ '0. US.
`“Ottice Action” for US. Appl. No. 10/249.202. Feb. 11. 2004. 6
`pages. Thel SPTO.
`IS.
`"()11icc Action” [or Ii.S. Appl No. 1()‘249.595. Apr. 272, 2004.
`pages. The USP"O. I S.
`“Ollice Action" for US. Appl. No. 10/249,774, Aug. 27. 2004. 6
`pages. The USP’ 0,
`IS.
`“01T'icc Action” for US. Appl. No. 10/249.844, Apr. 23. 2004, 5
`pages, The USPTO. .
`“Office Action” for L .S. Appl. No. 10/553393. Mar. 7. 2008. 6 pages.
`The USPTO. US.
`.S. Appl. No. 10/708,281. May 18. 2005. 15
`.
`“Office Action” for
`pages, The USPTO. _,S.
`“Olfice Action” for L.S. Appl. No. 10/708281, Dec. 20. 2005. 14
`pages, The USPTO. US.
`“01’fice Action” for US Appl. No. 10/710,946. Nov. 16. 200'/, 7
`pages, The USPTO, LS.
`“Ottice Action” for . .S. Appl. No. 101710.946. Feb. 21. 2008. 18
`pages, The USPTO.
`S.
`“Office Action” for
`.S. Appl. No. 10/710,946. Apr. 10, 2009. 18
`pages. The USPTO. L
`"Office Action” for US. Appl. No. 10/897,257. i\1ar. 27. 2008, 13
`pages. The USP" 0, JS.
`“Office Action” for U.S. Appl. No. 10/897,257. Jan. 14. 2009. 7
`pages. The USPTO,
`IS.
`"Ot1”1ce Action” for US. Appl.
`pages. The USP’ 0. US.
`“Office Action” for US. Appl. No.
`pages. The USP'‘(),
`.18.
`“Ottice Action” for US. Appl. No. 11/130.315. Jul. 3. 2008. 10
`pages. The USP’ '0. JS.
`"(.)tIice Action” for U.S. Appl. No. 11/162824, Apr. 28. 2008. 8
`pages. The USPTO. JS.
`"Ollice Action” for US Appl. No. 11 162,824. Jan. 23. 2009. 10
`pages. The US1”"(). US.
`
`

`
`US 7,811,421 B2
`Page 3
`
`“0ffice Action” for U8. Appl. No. 11/162824. May 18. 2009. 9
`pages. The USPTO. US.
`"Office Action” for U.S. Appl. No. 11/376.036. Jul. 25. 2007. 7
`pages. The USPTO, US.
`“Office Action” for 1.1.8. Appl. No. 11/608833. Mzu: 11. 200‘). 8
`pages. The L'SI”1'O. US.
`“Office Action” for U.S. Appl. No. 12 245.193, Apr. 2. 2009. 4 pages.
`The USPTO. US.
`Biberman. L. M.. et al.. Kinetics ofNonequi1ibriiim Low-Tempera-
`ture Plasmas. I987.
`Biigaev. S. P.. et al.. Investigation Of A High-Current Pulsed
`Magnetron Discharge Initiated In The I_ow—Pi’essure Diffuse Arc
`Plasma. XVIIth International Symposium On Discharges and Elec-
`tiical Insulation In Vacuum. 1996. pp. 1074-1076.
`Bugaev. S. P.. el al.. Ion-Assisted Pulsed \/lagnetron Sputtering
`Deposition OfTa-C Films. Thin Solid Films. 2001. pp. 16-26. vol.
`389, Elsevier Science B.V.. Feb. 2001.
`D’Couto. G. C. et 211.. In Situ Physical Vapor Deposition oflonized Ti
`and TiI\ Thin Films Using Ilollow ("athode Magnetron Plasma
`Source. J. Vac. Sci. Tcchnol. I3. .lari./Feb. 2001. pp. Z44-.149.\rol. 19.
`No. 1. American Vacuum Society.
`Ehiasarian. A. P.. et a1.. High Power Pulsed Magnetron Spuiiered
`CrVx Films. Dunnschicht-/Plasmalcchnik. 2003. pp. 1480-1487.
`Jun. 2003.
`I:'hiasarian. A. P.. et al.. Influence Of High Power Densities On The
`Composition OfPu1sed Magnetron Plasmas, Vacuum. 2002. pp. 147-
`154. vol. 65, Elsevier Science Ltd.
`Gudinundsson. J. T. et al.. Spatial and Temporal Behavior Of The
`Plasma Parameters In A Pulsed Magnetron Discharge. Surface and
`Coatings Technology. 2002. pp. 249-256. Vol. 161. Elsevier Science
`B.V.. Jul. 2002.
`Gudinundsson. J. T. et a1.. Evolution Of The Electron Energy Distri-
`bution And Plasma Parameters In A Pulsed Magnetron Discharge.
`Applied Physics Letters. May 28. 2001. pp. 3427-3429. vol. 78. No.
`22. American Institute Of Physics.
`Hopwood. J.. Ionized Physical Vapor Deposition Of Integrated Cir-
`cuit Intercoruiects. Physics Of Plasmas. May 1993. pp. 1624-1631.
`vol. 5. No. 5. American Institute Of Physics.
`Keivalishvii. N. A.. et a1.. Low-Pressure Discharge in Crossed Fields
`(El-I) In A Magnetron And Penning Cell. Sov. Phys. Tech. Phys..
`l976.pp. 1591-1596. V01. 20. No. 12. American lnstirutcOfPhysics
`Korneev, V.V.. Electric Fields In A Noneqiiilibrium Inhomogeneous
`Weakly Ionized Plasma. Sov. J. Plasma Phys.. Nov.-Dec. 1978. pp.
`784-785. vol. 4. No. 6. American Institute of Physics.
`Lebedev. S. Ya.. et a1.. Cathode Sputtering Under The Action Of
`Cesium Ions. Soviet Physics Technical Physics. Dec. 1964. pp.
`854-856. vol. 9. No. 6.
`Mesyats. G. A.. et al.. Pulsed Electrical Discharge In Vacuum.
`Springer—Verlag.
`(_)1<s.E. M.. et a1.. Plasma Emission Properties OfA Superdense Glow
`Discharge Excited In Crossed Electric And Magnetic Fields. Sov.
`Phys. Tech. Phys.. Jun. 1991. pp. 712-714. vol. 36. \1o. 6. American
`Institute of Physics.
`Rasmussen, C. E-.. et al.. Ionization And (Juirent Growth In An I3 X B
`Discharge. Plasma Physics. 1969. pp. 183-195. \ol.
`1 1. Pergamon
`Press. .\lorl.hern Ireland.
`Redhead. P. A.. Instabilities In Cross—Fie1d Discharges At Low Pres-
`sures. Vacuum.
`l988. pp. 901-906. vol. 38. No. 8-10. Pergamon
`Press. Great Britain.
`Steinbmchel. Ch.. A Simple Formula For Low-Energy Sputtering
`Yields. Appl. Phys. A.. 1985, pp. 37-42. vol. 36. Springer-Verlag.
`Westwood, W. D., The Current-Voltage Characteristic OfMagneLron
`Sputtering Systems, J. Appl. Phys.. Dec. 1983. pp. 6841-6846. vol.
`54. No. 12, American Institute Of Physics.
`“Notification Concerning Transmittal OfCopy Of International Pre-
`liminary Report On Patentability (Chapter I Of The Patent Coopera-
`tion Treaty)” For PCT/US2008/004644. Nov. 5. 2009. 10 pgs.. The
`International Bureau Of W IPO. Geneva. Switzerland.
`‘Notification Concerning Transmittal OfCopy Of International Pre-
`liminary Report On Patentability ("Chapter 1 Of The Patent Coopera-
`
`tion Treaty)” 1-'or PCT/US2008/004605. Oct. 29. 2009. 9 pgs.. The
`International Bureau OfWIPO. Geneva. Swit’/erland.
`“Office Action” For European Patent Application No 03-781-508.1 —
`1226. Apia 1. 2008. 5 pages. the European Patent Otticc.
`“Response to Ofiice Action" for Iziiropean Patent Application No
`0,4-1'81-5081-1226. Oct. 13. 2008. 13 pages.
`“Supplement to Response to Office Action” For European Patent
`Application No. 03-781 -508.1-1226. Oct. 23. 2008. 4 pages.
`“Office Action" For Furopean Patent Application No. 03-781-508. 1 -
`1226. Apr. 7. 20l(). 3 pages. the European Patent Office.
`“Officc Action” For European Patent Application No. ()3-779—”tS7.4-
`1215. Oct. 10. 2007. 4 pages. the European Patent Office
`“Response to Office Action” }"or liuropeaii Patent Application l\o.
`03-779-387.4-1215. Apr. 21. 2008. 15 pages.
`“Summons to Oral Proceedings” For European Patent Application
`No 03-779-387.4-1215. l)ec. 15. 2009. 6pages. the Eiiropean Patent
`Office.
`"Otticc Action” For 1".llI‘0p€£ln Patent App iciition No. 03-7 76-584 9-
`1226. Sep.
`lb’. 2008. 6 pages. the l'.Iiiropc2in Patent Ollicc
`"Response to Otlice Action" 1-or ljuropcan Patent Application i\'o
`()3-776-5849-1226. Jul. 23. 200‘). 12 pages
`"Oflicc Action“ 1'-‘or 1‘.l|1'0pCII1'1 Patent App icalioii No 04-749-844.9
`2208. Jan. 28. 2009. 7. pages. the F.uropean Patent Ollicc.
`“Ofiice Action” For 13uropean Patent Application No. 04-750-79’/.€.
`2208. Oct. 16. 2008, 5 pages. the lzuropean Patent ()1'Iice
`“Office Action" For European Patent App ication No. 04-7 16-928.‘)-
`2208. Dec. 15. 2006. 5 pages. the European Patent Office.
`“Response to Office Action” I-‘or European Patent Application No.
`04-716-928.9-2208..l1il. 24. 2007. 20 pages.
`"Office Action" For European Patent App ication No. 04-810-268.5.
`2208. Apr. 23. 2009. 3 pages. the Izuropean Patent Otfice.
`"Response to Office Action” For European Patent Application l\o.
`04-810-26852208. May 29. 2009. 2 pages.
`“Office Action" For European Patent App ication No. 05-723—194.6-
`1226. Nov. 5. 2009. 6 pages. the European Patent Officc.
`"Office Action” For European Patent Application No 05-800—880.6-
`1226. Jan. 25. 2010. 3 pages. the European Patent Otlice.
`“Office Action" For Japanese Patent Application No. 2004651595.
`Aug. 24. 2009. 2 pages. the Japanese Patent Office.
`“Response to Office Action” For Japanese Patent Application No.
`2004-551595. Feb 18. 2.010. 3 pages.
`“Notifice ofA11owance" For US Paten No. 7.147. 759. Oct. 11.2006.
`12 Pages. USP'1‘().
`“NotificeofAllowance” For USPa1en No 6.f<53.142.lV1aJ'.29.2004.
`20 Pages. USPTO.
`"Notifice 0fAllowance" For US Paten No. 7.604.716. Jun.
`16 Pages. USPTO.
`“Notifice of Allowance” For I?S Patent No. 6.896.773. Jan. 7. 7005.
`12 Pages. USPTO.
`“Notifice ofA1lowance” For US Paten .\lo. 6.896.775. Jan. 18. 2005.
`20 Pages. USPTO.
`“Notifice ofA11owance" For US Patent No. 6.806.651. Jul. 12. 2004.
`9 Pages. USPTO.
`"Notifice ofA11owance” I'or US Paton No. 7.446.479. Jul. 15. 2008.
`16 Pages. l.1SP'1'(,).
`"Notifice ofAllowarice” For US Paten No. 6.806.652. Jul. 2.. 2004. 9
`Pages. USPTO.
`"Notifice ofAllo\/Vance” For US Patent No. 6.90351 1. Nov. 2. 2005.
`9 Pages. USPTO.
`"Notifice ofAl1owance” for US Patent No. 6.805.779. Jun. 29. 2004
`14 Pages. USPTO.
`"Notifice ofAl1owance” for US Patent No. 7.095.179. May 2. 2006.
`18 Pages. USPTO.
`1
`“Notifice ofAllowance” For US Patent No. 7.34€.429. Nov. 30. 2007.
`8 Pages. USPTO
`“Notificc ofAl1owancc” For US Patent No. 7.663.319. Oct. 8. 2009.
`50 Pages. USPTO.
`US 5.863.392, 01/1999. l)i'ummond et al. (withdrawn)
`
`1 1.2009.
`
`"‘ cited by examiner
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`U.S. Patent
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`Oct. 12, 2010
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`Oct. 12, 2010
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`
`U.S. Patent
`
`Oct. 12, 2010
`
`Sheet 11 M13
`
`US 7,811,421 B2
`
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`
`U.S. Patent
`
`Oct. 12, 2010
`
`Sheet 12 0f13
`
`US 7,811,421 B2
`
`650
`
`PUMP DOWN CHAMBER
`
`/ 504
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`PASS FEED GAS INTO CHAMBER
`PROXIMATE TO A CATHODE (TARGET) ASSEMBLY
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`PRESSURE
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`FIELD PROXIMATE TO FEED GAS
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`FIG. 11A
`
`FIG. 113
`
`FIG. 11
`
`IONIZE FEED GAS TO GENERATE
`WEAKLY-IONIZED PLASMA
`
`
`
`FIG. 11A
`
`

`
`U.S. Patent
`
`Oct. 12, 2010
`
`Sheet 13 0f13
`
`Us 7,811,421 B2
`
`0
`
`622
`
`GENERATE STRONGLY-IONIZED
`PLASMA FROM WEAKLY-IONIZED PLASMA
`
`
`
`EXCHANGE STRONGI.Y—IONIZED
`PLASMA WITH FEED GAS
`
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`STRONGLY-
`IONIZE D?
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`MONITOR SPUTTER YIELD
`
`628
`
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`SPUTTER
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`YIELD
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`
`END
`
`FIG. 11B
`
`

`
`US 7,811,421 B2
`
`1
`HIGH DEPOSITION RATE SPUTTERING
`
`R ELATED APPLICATION SECTION
`
`This application claims priority to U.S. patent application
`Ser. No. ll/091.814, filed Mar. 28, 2005, and entitled “High
`Deposition Rate Sputtering”. which is a continuation ol'U.S.
`patent application. Ser. No. 10/065,739. filed Nov. 14, 2002.
`and etititled “High Deposition Rate Sputtering". which is now
`US. Pat. No. 6.896.773. the entire application and patent of
`which are incorporated herein by reference.
`
`BACKGROUND OF INVENTION
`
`Sputtering is a well-known technique for depositing films
`on substrates. Sputtering is the physical ejection of atoms
`from a target surface and is sometimes referred to as physical
`vapor deposition (PVD). Ions, such as argon ions. are gener-
`ated and then directed to a target surface where the ions
`physically sputter target material atoms. The target material
`atoms ballistically flow to a substrate where they deposit as a
`film of target material.
`Diode sputtering systems include a target and an anode.
`Sputtering is achieved in a diode sputtering system by estab-
`lishing an electncal discharge in a gas between two parallel-
`plate electrodes inside a chamber. A potential of several kilo-
`volts is typically applied between planar electrodes in an inert
`gas atmosphere (e.g., argon) at pressures that are between
`about 10” and 10-2 Torr. A plasma discharge is then formed.
`The plasma discharge is separated from each electrode by
`what is referred to as the dark space.
`The plasma discharge has a relatively constant positive
`potential with respect to the target. Ions are drawn out of the
`plasma. and are accelerated across the cathode dark space.
`The target has a lower potential than the region in which the
`plasma is formed. Therefore. the target attracts positive ions.
`Positive ions move towards the target with a high velocity.
`Positive ions then impact the target and cause atoms to physi-
`cally dislodge or sputter from the target. The sputtered atoms
`then propagate to a substrate where they deposit a film of
`sputtered target material. The plasma is replenished by elec-
`tron-ion pairs formed by the collision of neutral molecules
`with secondary electrons generated at the target surface.
`Magnetron sputtering systems Lise magnetic fields that are
`shaped to trap and to concentrate secondary electrons, which
`are produced by ion bombardment of the target surface. The
`plasma discharge generated by a magnetron sputtering sys-
`tem is located proximate to the surface of the target and has a
`high density ofelectrons. The hi gh density ofelectrons causes
`ionization of the sputtering gas in a region that is close to the
`target surface.
`One type of magnetron sputtering system is a planar mag-
`netron sputtering system. Planar magnetron sputtering sys-
`tems are similar in configuration to diode sputtering systems.
`However. the magnets (permanent or electromagnets) in pla-
`nar magnetron sputtering systems are placed behind the cath-
`ode. The magnetic field lines generated by the magnets enter
`and leave the target cathode substantially normal to the cath-
`ode surface. Electrons are trapped in the electric and ma gnctic
`fields. The trapped electrons enhance the efficiency of the
`discharge and reduce the energy dissipated by electrons arriv-
`ing at the substrate.
`Conventional magnetron sputtering systems deposit films
`that have relatively low uniformity. The film uniformity can
`be increased by mechanically moving the substrate and/or the
`magnetron. However, such systems are relatively complex
`and expensive to implement. Conventional magnetron spitt-
`
`'J\
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`
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`
`20
`
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`
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`
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`
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`tering systems also have relatively poor target utili7ation.'1"he
`term “target utilization” is defined herein to be a metric of
`how uniform the target material erodes during sputtering. l"or
`example. high target utili7.ation would indicate that the target
`material erodes in a highly uniform manner.
`In addition, conventional magnetron sputtering systems
`have a relatively low deposition rate. The term “deposition
`rate" is defined herein to mean the amount of material depos-
`ited on the substrate per unit oftime. In general. the deposi-
`tion rate is proportional
`to the sputtering yield. The term
`“sputtering yield" is defined herein to mean the number of
`target atoms ejected from the target per incident particle.
`Thus. increasing the sputtering yield will increase the depo-
`sition rate.
`
`BRIEF DESCRIPTION OF DRAWINGS
`
`This invention is described with particularity in the
`detailed description. The above and further advantages ofthis
`invention may be better understood by referring to the fol-
`lowing description in conjunction with the accompanying
`drawings. in which like numerals indicate like structural ele-
`ments and features in various figures. The drawings are not
`necessarily to scale. emphasis instead being placed upon
`illustrating the principles of the invention.
`FIG. 1 illustrates a cross-sectional view of a known mag-
`netron sputtering apparatus having a pulsed power source.
`FIG. 2 illustrates a cross—sectional view ofa prior art cath-
`ode assembly having a cathode cooling system.
`FIG. 3 illustrates a known process for sputtering material
`from a target.
`FIG. 4 illustrates a eross~sectional view ofan embodiment
`ofa magnetron sputtering apparatus according to the present
`invention.
`FIGS. 5./\. AB. AC. SI) illustrate cross—sectional views of
`the magnetron sputtering apparatus ofl“l(.i. 4.
`l"1(l. 6 illustrates graphical representations of the applied
`voltage. current. and power as a function olitime for periodic
`pulses applied to the plasma in the magnetron sputtering
`apparatus of FIG. 4.
`FIGS. 7A. 713. 7C‘, 7D illustrate various simulated mag-
`netic field distributions proximate to the cathode assembly for
`various electron 13x13 drift currents
`in a magnetically
`enhanced plasma sputtering apparatus according to the inven-
`tion.
`
`FIG. 8 illustrates a graphical representation of sputtering
`yield as a function of temperature of the sputtering target.
`FIG. 9 illustrates a process for sputtering material frotn a
`target according one embodiment of the present invention.
`FIG. 10 illustrates a cross-sectional view of a cathode
`assembly according to one embodiment ofthe invention.
`FIGS. ll. 11A. 1 113 is a flowchart ofan illustrative process
`ofenhancing a sputtering yield ofa sputtering target accord-
`ing to the present invention.
`
`DF,TAlI,F.D DF.S(‘Rll"l'lON
`
`60
`
`65
`
`The sputtering process can be quantified in terms of the
`sputtering yield. The term “sputtering yield” is defined herein
`to mean the number oftarget atoms ejected from the target per
`incident particle. The sputtering yield depends on several
`factors. such as the target species. bombarding species.
`energy ofthe bombarding ions. and the angle of incidence o 1'
`the bombarding ions. In typical known sputtering processes.
`the sputtering yield is generally insensitive to target tempera-
`ture.
`
`

`
`US 7,811,421 B2
`
`3
`The deposition rate of a sputtering process is generally
`proportional to the sputtering yield. Thus, increasing the sput-
`tering yield typically will increase the deposition rate. One
`way to increase the sputtering yield is to increase the ion
`density of the plasma so that a larger ion flux impacts the
`surface of the target. The density of the plasma is generally
`proportional
`to the number of ionizing collisions in the
`plasma.
`Magnetic fields can be used to confine electrons in the
`plasma to increase the number oliionizing collisions between
`electrons and neutral atoms in the plasma. The tnagnetic and
`electric fields in magnetron sputtering systems are concen-
`trated in narrow regions close to the surface of the target.
`These narrow regions are located between the poles of the
`magnets used for producing the magnetic field. Most of the
`ionization of the sputtering gas occurs in these localized
`regions. The location of the ionization regions causes non-
`uniform erosion or wear 01.1116 target that results in poor target
`utilization.
`
`h:-creasing the power applied between the target and the
`anode can increase the production of ionized gas and. there-
`fore, increase the target utilization and the sputtering yield
`However, increasing the applied power can lead to undesir-
`able target heating and target damage. Furthermore. increas-
`ing the Voltage applied between the target and the anode
`increases the probability of establishing an undesirable elec-
`trical discharge (an electrical arc) in the process chamber. An
`undesirable electrical discharge can corrupt the sputtering
`process.
`Pulsing the power applied to the plasma can be advanta-
`geous since the average discharge power can remain low
`while relatively large power pulses are periodically applied.
`Additionally, the duration ofthese large voltage pulses can be
`preset so as to reduce the probability ofestablishing an elec-
`trical breakdown condition leading to an undesirable electri-
`cal discharge. Howevcr, very large power pulses can still
`result in undesirable electrical discharges and undesirable
`target heating regardless of their duration.
`FIG. 1 illustrates a eross—seet'ional view ofa known mag-
`netron sputtering apparatus l00 having a pulsed power source
`102. The known magnetron sputtering apparatus 100 includes
`a vacuum chamber 104 where the sputtering process is per-
`formed. The vacuum chamber 104 is positioned in fluid com-
`munication with a vacuum pump 106 via a conduit 108. '1 he
`vacuum pump 106 is adapted to evacuate the vacuum cham-
`ber 104 to high vacuum. The pressure inside the vactnun
`chamber 104 is generally less than 100 Pa during operation. A
`feed gas source 109. such as an argon gas source, is coupled
`to the vacuum chamber 104 by a gas inlet "110. A valve 112
`controls the gas flow from the feed gas source 109.
`The magnetron sputtering apparatus 100 also includes a
`cathode assembly 114 having a target 116. The cathode
`assembly 114 is generally in the shape ofa circular disk. The
`cathode assembly 114 is electrically connected to a first out-
`put 118 of the pulsed power supply 102 with an electrical
`transmission line 120. The cathode assembly 114 is typically
`coupled to the negative potential of the pulsed power supply
`102. In order to isolate the cathode assembly 114 from the
`vacuum chamber 104, an insulator 122 can be used to pass the
`electrical transmission line 120 through a wall of the vacuum
`chamber 104. A grounded shield 124 can be positioned
`behind the cathode assembly 114 to protect a magnet 126
`from bombarding ions. The magnet 126 shown in FIG. 1 is
`generally shaped in the form of a ring that has its south pole
`127 on the inside of the ring and its north pole 128 on the
`outside of the ring. Matty other magnet configurations can
`also be used.
`
`‘.11
`
`10
`
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`
`30
`
`40
`
`45
`
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`
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`
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`
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`
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`An anode 130 is positioned in the vacuum chamber 104
`proximate to the cathode assembly 114. Tlievanode 130 is
`typically coupled to ground. A second output 132 of the
`pulsed power supply 102 is also typically coupled to ground.
`A substrate 134 is positioned in the vacuum chamber 104 on
`a substrate support 135 to receive the sputtered target n:aterial
`lrom the target 116. The substrate 134 can be electrically
`connected to a bias voltage power supply 136 with a trans-
`mission line 138. In order to isolate the bias voltage power
`supply 136 from the vacutnn chamber 104. an insulator 140
`can be used to pass the electrical
`transmission line 138
`through a wall of the vacuum chamber 104.
`In operation. the pulsed power supply 102 applies a voltage
`pulse between the cathode assembly 114 and the anode 130
`that has a sulificient amplitude to ionize the argon teed gas 11]
`the vacuum chamber 104. The typical ionization process is
`referred to as direct ioni‘z.ation or atomic ioni/.ation by elec-
`tron impact and can be described as follows:
`Arte ->.~\t ‘ 4.39
`
`where Ar represents a neutral argon atom in the feed gas
`and e‘ represents an ionizing electron generated in response
`to the voltage pulse applied between the cathode assembly
`114 and the anode 130. The collision between the neutral
`argon atom and the ionizing electron results in an argon ion
`(AF) and two electrons.
`The negatively biased cathode assembly 114 attracts posi-
`tively charged ions with sut°ficient acceleration so that the ions
`sputter the target material from the target 1 16. A portion ofthe
`sputtered target material is deposited on the substrate 134.
`The electrons, which cause the ionization. are generally
`confined by the magnetic fields produced by the magnet 126.
`The magnetic conlinement
`is strongest
`in a continement
`region 142 where there is relatively low magnetic held inten-
`sity. The confinement region 142 is substantially in the shape
`of a ring that is located proximate to the target material.
`Generally, a higher concentration of positive