(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2006/0238209 A1
`Oct. 26, 2006
`(43) Pub. Date:
`Chen et al.
`
`US 20060238209A1
`
`(54)
`
`(75)
`
`(73)
`(21)
`(22)
`
`(63)
`
`VERTICAL MICROPROBES FOR
`CONTACTING ELECTRONIC
`COMPONENTS AND METHOD FOR
`MAKING SUCH PROBES
`
`Inventors: Richard T. Chen, Burbank, CA (US);
`Ezekiel J.J. Kruglick, San Diego, CA
`(US); Christopher A. Bang, San
`Diego, CA (US); Vacit Arat, La
`Canada Flintridge, CA (US); Adam L.
`Cohen, Van Nuys, CA (US); Kieun
`Kim, Pasadena, CA (US); Gang
`Zhang, Monterey Park, CA (US);
`Dennis R. Smalley, Newhall, CA (US)
`Correspondence Address:
`MCROFABRICA INC.
`ATT DENNIS R. SMALLEY
`7911 HASKELLAVENUE
`VAN NUYS, CA 91406 (US)
`Assignee: Microfabrica Inc.
`Appl. No.:
`11/325,404
`
`Filed:
`
`Jan. 3, 2006
`
`Related U.S. Application Data
`Continuation-in-part of application No. 10/949,738,
`filed on Sep. 24, 2004.
`Continuation-in-part of application No. 11/029, 180,
`filed on Jan. 3, 2005.
`Continuation-in-part of application No. 10/677.556,
`filed on Oct. 1, 2003.
`Continuation-in-part of application No. 11/173,241,
`filed on Jun. 30, 2005.
`Said application No. 10/949,738 is a continuation-in
`part of application No. 10/772,943, filed on Feb. 4,
`2004, now abandoned, and which is a continuation
`in-part of application No. 10/949,738, filed on Sep.
`24, 2004.
`Said application No. 11/173,241 is a continuation-in
`part of application No. 11/028,958, filed on Jan. 3,
`
`
`
`2005, and which is a continuation-in-part of applica
`tion No. 10/434,943, filed on May 8, 2003, and which
`is a continuation-in-part of application No. 11/029,
`217, filed on Jan. 3, 2005, and which is a continua
`tion-in-part of application No. 11/028,945, filed on
`Jan. 3, 2005, and which is a continuation-in-part of
`application No. 11/029,221, filed on Jan. 3, 2005, and
`which is a continuation-in-part of application No.
`11/028,960, filed on Jan. 3, 2005, and which is a
`continuation-in-part of application No. 10/772,943,
`filed on Feb. 4, 2004, now abandoned, and which is
`a continuation-in-part of application No. 10/949,738,
`filed on Sep. 24, 2004, and which is a continuation
`in-part of application No. 10/434,493, filed on May 7,
`2003, and which is a continuation-in-part of applica
`tion No. 10/949,738, filed on Sep. 24, 2004, and
`which is a continuation-in-part of application No.
`10/949,738, filed on Sep. 24, 2004, and which is a
`continuation-in-part of application No. 10/949,738,
`filed on Sep. 24, 2004.
`Provisional application No. 60/641,341, filed on Jan.
`3, 2005. Provisional application No. 60/445,186, filed
`on Feb. 4, 2003. Provisional application No. 60/506,
`015, filed on Sep. 24, 2003. Provisional application
`No. 60/533,933, filed on Dec. 31, 2003. Provisional
`application No. 60/536,865, filed on Jan. 15, 2004.
`(Continued)
`Publication Classification
`
`(60)
`
`(51)
`
`(52)
`
`Int. C.
`(2006.01)
`GOIR 3L/02
`U.S. Cl. .............................................................. 324/754
`
`(57)
`ABSTRACT
`Multilayer probe structures for testing or otherwise making
`electrical contact with semiconductor die or other electronic
`components are electrochemically fabricated via depositions
`of one or more materials in a plurality of overlaying and
`adhered layers. In some embodiments the structures may
`include configurations intended to enhance functionality,
`buildability, or both.
`
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`US 2006/0238209 A1
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`
`Related U.S. Application Data
`Provisional application No. 60/506,015, filed on Sep.
`24, 2003. Provisional application No. 60/533,933,
`filed on Dec. 31, 2003. Provisional application No.
`60/536,865, filed on Jan. 15, 2004. Provisional appli
`cation No. 60/533,933, filed on Dec. 31, 2003. Pro
`visional application No. 60/536,865, filed on Jan. 15,
`2004. Provisional application No. 60/540.511, filed
`on Jan. 29, 2004. Provisional application No. 60/582,
`726, filed on Jun. 23, 2004. Provisional application
`No. 60/540,510, filed on Jan. 29, 2004. Provisional
`application No. 60/533,897, filed on Dec. 31, 2003.
`Provisional application No. 60/415,374, filed on Oct.
`1, 2002. Provisional application No. 60/533,947, filed
`on Dec. 31, 2003. Provisional application No. 60/533,
`933, filed on Dec. 31, 2003. Provisional application
`No. 60/536,865, filed on Jan. 15, 2004. Provisional
`application No. 60/540.511, filed on Jan. 29, 2004.
`Provisional application No. 60/379,177, filed on May
`7, 2002. Provisional application No. 60/442,656, filed
`on Jan. 23, 2003. Provisional application No. 60/533,
`975, filed on Dec. 31, 2003. Provisional application
`No. 60/540,510, filed on Jan. 29, 2004. Provisional
`
`application No. 60/533,933, filed on Dec. 31, 2003.
`Provisional application No. 60/536,865, filed on Jan.
`15, 2004. Provisional application No. 60/540.511,
`filed on Jan. 29, 2004. Provisional application No.
`60/533,948, filed on Dec. 31, 2003. Provisional appli
`cation No. 60/574,737, filed on May 26, 2004. Pro
`visional application No. 60/533,897, filed on Dec. 31,
`2003. Provisional application No. 60/533,975, filed
`on Dec. 31, 2003. Provisional application No. 60/533,
`947, filed on Dec. 31, 2003. Provisional application
`No. 60/533,948, filed on Dec. 31, 2003. Provisional
`application No. 60/540,510, filed on Jan. 29, 2004.
`Provisional application No. 60/582,689, filed on Jun.
`23, 2004. Provisional application No. 60/582,690,
`filed on Jun. 23, 2004. Provisional application No.
`60/609,719, filed on Sep. 13, 2004. Provisional appli
`cation No. 60/611,789, filed on Sep. 20, 2004. Pro
`visional application No. 60/540.511, filed on Jan. 29.
`2004. Provisional application No. 60/533,933, filed
`on Dec. 31, 2003. Provisional application No. 60/536,
`865, filed on Jan. 15, 2004. Provisional application
`No. 60/533,947, filed on Dec. 31, 2003.
`
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`

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`Patent Application Publication Oct. 26, 2006 Sheet 1 of 24
`
`US 2006/0238209 A1
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`12
`
`10N252N2. 5 f
`
`
`
`if
`
`FIG 1A
`
`6
`
`
`
`
`
`
`
`2 2
`
`
`
`
`
`%
`2
`Y
`FIG 1F
`6
`
`FIG 1G
`
`6
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`

`

`16
`
`15
`
`1
`
`6
`
`12
`
`w a
`
`\
`
`
`
`
`
`
`
`4
`
`2
`
`4
`
`
`
`2
`
`s.
`
`
`
`2° C:
`
`‘ £17 _
`:
`20
`
`
`%////////////////¢»
`
`FIG 2F
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`Patent Application Publication Oct. 26, 2006 Sheet 3 of 24
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`US 2006/0238209 A1
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`
`
`32
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`Page 5 of 39
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`

`

`s
`
`FIG 4C
`
`FIG 4D
`
`
`
`
`
`
`
`
`
`
`
`FIG 4E
`
`4 96 94 94 96
`
`S.S.
`SSSSSSSS
`S.S.S.
`ISSSSSSSSSSS:
`
`
`
`FIG 4G
`
`FIG 4H
`
`
`
`S. S.
`SSSSSSSSSS
`SS SS
`S
`SS
`
`SS SS
`S
`SS
`SS
`SS
`
`FIG 4
`
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`

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`Patent Application Publication Oct. 26, 2006 Sheet 5 of 24
`
`US 2006/0238209 A1
`
`106
`
`
`
`109
`
`108
`
`1 O2
`
`108
`
`108
`
`104
`
`FIG 5A
`
`FIG 5C
`
`FIG 5D
`
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`Patent Application Publication Oct. 26, 2006 Sheet 6 of 24
`
`US 2006/0238209 A1
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`
`
`147
`
`147
`
`FIG 5E
`
`
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`Patent Application Publication Oct. 26, 2006 Sheet 7 of 24
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`US 2006/0238209 A1
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`
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`Patent Application Publication Oct. 26, 2006 Sheet 8 of 24
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`US 2006/0238209 A1
`
`FIG 8
`
`
`
`FIG 9
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`Patent Application Publication Oct. 26, 2006 Sheet 9 of 24
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`US 2006/0238209 A1
`
`
`
`
`
`FIG 11
`
`FIG 12
`
`FIG 13
`
`FIG 14
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`Patent Application Publication Oct. 26, 2006 Sheet 10 of 24
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`US 2006/0238209 A1
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`
`
`FIG 15A
`
`FIG 15B
`
`FIG 16A
`
`FG 16B
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`Patent Application Publication Oct. 26, 2006 Sheet 11 of 24
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`US 2006/0238209 A1
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`FIG 17
`
`
`
`FIG 18A
`
`
`
`FG 18B
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`Patent Application Publication Oct. 26, 2006 Sheet 12 of 24
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`US 2006/0238209 A1
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`
`
`204
`
`|
`
`204
`
`FIG 19B
`
`204
`
`FG 20A
`204
`
`8
`
`|
`
`??
`
`FIG 19A
`
`204
`
`FIG 20B 202
`
`FIG 20O
`
`FG 200
`
`FIG 20E
`
`O4.
`
`FIG 20F
`
`FIG 20G
`
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`Patent Application Publication Oct. 26, 2006 Sheet 13 of 24
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`US 2006/0238209 A1
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`FIG 21
`
`FIG 22
`
`
`
`FIG 23
`
`FIG 24
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`Patent Application Publication Oct. 26, 2006 Sheet 14 of 24
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`US 2006/0238209 A1
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`302
`
`
`
`FIG 26
`
`FIG 27
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`Patent Application Publication Oct. 26, 2006 Sheet 15 of 24
`
`US 2006/0238209 A1
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`FIG 28A
`
`FIG 28B
`
`
`
`FIG 29
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`Patent Application Publication Oct. 26, 2006 Sheet 16 of 24
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`US 2006/0238209 A1
`
`
`
`FIG 31
`
`FIG 32A
`
`
`
`Š
`
`FIG 32B
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`Patent Application Publication Oct. 26, 2006 Sheet 17 of 24
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`US 2006/0238209 A1
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`458
`
`454
`
`456
`
`454
`
`454
`
`458"
`
`454
`
`FIG 34A
`
`FIG 34B
`
`FIG 34C
`
`
`
`FIG 35A
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`Patent Application Publication Oct. 26, 2006 Sheet 18 of 24
`
`US 2006/0238209 A1
`
`Figure 35B
`
`
`
`FIG 36A
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`Patent Application Publication Oct. 26, 2006 Sheet 19 of 24
`
`US 2006/0238209 A1
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`FIG 36B
`
`
`
`FIG 37
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`Patent Application Publication Oct. 26, 2006 Sheet 20 of 24
`
`US 2006/0238209 A1
`
`
`
`agn bet WDF
`SE 275 astf
`
`Spot Magh Det WO Hin 20 in
`KW 4.0 802 SE 276 last
`
`FIG 39A
`
`FIG 39B
`
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`Patent Application Publication Oct. 26, 2006 Sheet 21 of 24
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`US 2006/0238209 A1
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`
`
`
`
`Spot agree if
`xi W.
`y
`604r s 24 as
`
`Barn
`
`Spot figh de W - - - -
`C.W.
`kW
`82.8 s 24 as
`
`3
`
`- -- 2:r
`
`FIG 39C
`
`
`
`FIG 39D
`
`FIG 39E
`
`
`
`
`
`spxt Magh Det W -- "r
`Rice.w
`kW
`its 328 st.tif
`
`k
`
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`
`as a 8
`8
`
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`
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`a:
`
`* 3:... . . .
`
`lawspatianisatis
`to kW
`802x SE 277 lastef
`
`r
`
`FIG 39F
`
`FIG 39GD
`
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`Patent Application Publication Oct. 26, 2006 Sheet 22 of 24
`
`US 2006/0238209 A1
`
`accwmississincewic
`EEEssass
`
`C.W.
`k
`
`Spot Magne. WR -
`c 82 SE 27
`ast
`
`20 m
`
`FIG 39H
`
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`
`Spot wagi dei wo
`cc.w
`o,
`kW 3, 4x Se 2.5 last.f
`
`FIG 39J
`
`FIG 39K
`
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`Patent Application Publication Oct. 26, 2006 Sheet 23 of 24
`
`US 2006/0238209 A1
`
`FIG 39.
`
`FIG 39M
`
`
`
`
`
`FIG 390
`
`FIG 40A
`
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`Page 25 of 39
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`Patent Application Publication Oct. 26, 2006 Sheet 24 of 24
`
`US 2006/0238209 A1
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`
`
`
`
`
`
`
`
`FIG 4OB
`
`FIG 41A
`
`NS
`
`Y
`
`N
`
`RNASW
`
`506
`
`FIG 42
`
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`

`US 2006/0238209 A1
`
`Oct. 26, 2006
`
`VERTICAL MICROPROBES FOR CONTACTING
`ELECTRONIC COMPONENTS AND METHOD FOR
`MAKING SUCH PROBES
`
`RELATED APPLICATIONS
`0001. This application claims benefit of U.S. App. No.
`60/641,341, filed Jan. 3, 2005, and is a continuation-in-part
`of U.S. application Ser. No. 10/949,738, filed Sep. 24, 2004;
`Ser. No. 11/029, 180, filed Jan. 3, 2005: Ser. No. 10/677,556,
`filed Oct. 1, 2003; and Ser. No. 11/173,241, filed Jun. 30,
`2005. The 738 application is a continuation-in-part of U.S.
`Non-Provisional patent application Ser. No. 10/772,943 filed
`on Feb. 4, 2004, which in turn claims benefit of U.S.
`Provisional Patent Application Nos. 60/445,186; 60/506,
`015; 60/533,933, and 60/536,865 filed on Feb. 4, 2003; Sep.
`24, 2003: Dec. 31, 2003; and Jan. 15, 2004 respectively:
`furthermore the 738 application claims benefit of U.S.
`Provisional Patent Application Nos. 60/506,015; 60/533,
`933; and 60/536,865 filed on Sep. 24, 2003: Dec. 31, 2003:
`and Jan. 15, 2004, respectively. The 180 application claims
`benefit of U.S. App. Nos. 60/533,933, 60/536,865, 60/540,
`511, 60/582,726, 60/540,510, and 60/533,897 and is a con
`tinuation-in-part of U.S. application Ser. No. 10/949,738.
`The 556 application in turn claims benefit of U.S. App. No.
`60/415,374, filed Oct. 1, 2002. The 556 application is a
`continuation-in-part of U.S. application Ser. No. 11/028,958,
`filed Jan. 3, 2005: Ser. No. 10/434,943, filed May 7, 2003:
`Ser. No. 11/029,217, filed Jan. 3, 2005: Ser. No. 11/028,945,
`filed Jan. 3, 2005: Ser. No. 11/029,221, filed Jan. 3, 2005;
`and Ser. No. 11/028,960, filed Jan. 3, 2005. The 958
`application in turn claims benefit of U.S. App. Nos. 60/533,
`947, filed Dec. 31, 2003; 60/533,933, filed Dec. 31, 2003:
`60/536,865, filed Jan. 15, 2004; and 60/540,511, filed Jan.
`29, 2004 and is a continuation in part of U.S. application Ser.
`No. 10/772,943, filed Feb. 4, 2004; Ser. No. 10/949,738,
`filed Sep. 24, 2004; and Ser. No. 10/434,493, filed May 7,
`2003. The 493 application claims benefit of U.S. App. No.
`60/379,177, filed May 7, 2002, and 60/442,656, filed Jan.
`23, 2003. The 217 application claims benefit of U.S. App.
`Nos. 60/533,975, filed Dec. 31, 2003; 60/540,510, filed Jan.
`29, 2004; 60/533,933, filed Dec. 31, 2003; 60/536,865, filed
`Jan. 15, 2004; and 60/540,511, filed Jan. 29, 2004, and is a
`continuation in part of U.S. application Ser. No. 10/949,738,
`filed Sep. 24, 2004. The 945 application claims benefit of
`U.S. Provisional Patent Application Nos. 60/533,948, filed
`Dec. 31, 2003; and 60/574,737, filed May 26, 2003. The
`221 application claims benefit to U.S. App. Nos. 60/533,
`897, filed Dec. 31, 2003; 60/533,975, 60/533,947, filed Dec.
`31, 2003; and 60/533,948, filed Dec. 31, 2003; and to
`60/540,510, filed Jan. 29, 2004; and is a CIP of U.S. patent
`application Ser. No. 10/949,738, filed Sep. 24, 2004. The
`960 application claims benefit of U.S. App. Nos. 60/582,
`689, filed Jun. 23, 2004; 60/582,690, filed Jun. 23, 2004;
`60/609,719, filed Sep. 13, 2004; 60/611,789, filed Sep. 20,
`2004; 60/540,511, filed Jan. 29, 2004; 60/533,933, filed Dec.
`31, 2003; 60/536,865, filed Jan. 15, 2004 and 60/533,947,
`filed Dec. 31, 2003 and is a CIP of U.S. patent application
`Ser. No. 10/949,738, filed Sep. 24, 2004. Each of these
`applications, including any appendices attached thereto, is
`incorporated herein by reference as if set forth in full herein.
`
`FIELD OF THE INVENTION
`0002 Embodiments of the present invention relate to
`microprobes (e.g. for use in the wafer level testing of
`
`integrated circuits) and more particularly to microprobes
`that have a base end and a contact tip end which makes
`contact with an electronic component has it is compressed
`toward the base end. Other embodiments pertain to fabri
`cation of Such probes using electrochemical fabrication
`methods.
`
`BACKGROUND OF THE INVENTION
`0003) Electrochemical Fabrication:
`0004. A technique for forming three-dimensional struc
`tures (e.g. parts, components, devices, and the like) from a
`plurality of adhered layers was invented by Adam L. Cohen
`and is known as Electrochemical Fabrication. It is being
`commercially pursued by Microfabrica Inc. (formerly
`MEMGen R. Corporation) of Burbank, Calif. under the name
`EFABTM. This technique was described in U.S. Pat. No.
`6,027,630, issued on Feb. 22, 2000. This electrochemical
`deposition technique allows the selective deposition of a
`material using a unique masking technique that involves the
`use of a mask that includes patterned conformable material
`on a Support structure that is independent of the Substrate
`onto which plating will occur. When desiring to perform an
`electrodeposition using the mask, the conformable portion
`of the mask is brought into contact with a substrate while in
`the presence of a plating solution Such that the contact of the
`conformable portion of the mask to the substrate inhibits
`deposition at selected locations. For convenience, these
`masks might be generically called conformable contact
`masks; the masking technique may be generically called a
`conformable contact mask plating process. More specifi
`cally, in the terminology of Microfabrica Inc. (formerly
`MEMGen R. Corporation) of Burbank, Calif. Such masks
`have come to be known as INSTANT MASKSTM and the
`process known as INSTANT MASKINGTM or INSTANT
`MASKTM plating. Selective depositions using conformable
`contact mask plating may be used to form single layers of
`material or may be used to form multi-layer structures. The
`teachings of the 630 patent are hereby incorporated herein
`by reference as if set forth in full herein. Since the filing of
`the patent application that led to the above noted patent,
`various papers about conformable contact mask plating (i.e.
`INSTANT MASKING) and electrochemical fabrication
`have been published:
`0005 1. A. Cohen, G. Zhang, F.Tseng, F. Mansfeld, U.
`Frodis and P. Will, “EFAB: Batch production of func
`tional, fully-dense metal parts with micro-scale fea
`tures, Proc. 9th Solid Freeform Fabrication, The Uni
`versity of Texas at Austin, p 161, August 1998.
`0006 2. A. Cohen, G. Zhang, F.Tseng, F. Mansfeld, U.
`Frodis and P. Will, “EFAB: Rapid, Low-Cost Desktop
`Micromachining of High Aspect Ratio True 3-D
`MEMS, Proc. 12th IEEE Micro Electro Mechanical
`Systems Workshop, IEEE, p 244, January 1999.
`0007 3. A. Cohen, “3-D Micromachining by Electro
`chemical Fabrication, Micromachine Devices, March
`1999.
`0008 4. G. Zhang, A. Cohen, U. Frodis, F. Tseng, F.
`Mansfeld, and P. Will, “EFAB: Rapid Desktop Manu
`facturing of True 3-D Microstructures'. Proc. 2nd
`International Conference on Integrated MicroNano
`technology for Space Applications, The Aerospace Co.,
`April 1999.
`
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`Oct. 26, 2006
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`0009) 5. F. Tseng, U. Frodis, G. Zhang, A. Cohen, F.
`Mansfeld, and P. Will, “EFAB: High Aspect Ratio,
`Arbitrary 3-D Metal Microstructures using a Low-Cost
`Automated Batch Process', 3rd International Work
`shop on High Aspect Ratio MicroStructure Technology
`(HARMST 99), June 1999.
`0010) 6. A. Cohen, U. Frodis, F. Tseng, G. Zhang, F.
`Mansfeld, and P. Will, “EFAB: Low-Cost, Automated
`Electrochemical Batch Fabrication of Arbitrary 3-D
`Microstructures’, Micromachining and Microfabrica
`tion Process Technology, SPIE 1999 Symposium on
`Micromachining and Microfabrication, September
`1999.
`0011 7. F. Tseng, G. Zhang, U. Frodis, A. Cohen, F.
`Mansfeld, and P. Will, “EFAB: High Aspect Ratio,
`Arbitrary 3-D Metal Microstructures using a Low-Cost
`Automated Batch Process, MEMS Symposium,
`ASME 1999 International Mechanical Engineering
`Congress and Exposition, November, 1999.
`0012 8. A. Cohen, “Electrochemical Fabrication
`(EFABTM), Chapter 19 of The MEMS Handbook,
`edited by Mohamed Gad-EI-Hak, CRC Press, 2002.
`0013 9. Microfabrication-Rapid Prototyping's Killer
`Application’, pages 1-5 of the Rapid Prototyping
`Report, CAD/CAM Publishing, Inc., June 1999.
`0014. The disclosures of these nine publications are
`hereby incorporated herein by reference as if set forth in full
`herein.
`0.015 The electrochemical deposition process may be
`carried out in a number of different ways as set forth in the
`above patent and publications. In one form, this process
`involves the execution of three separate operations during
`the formation of each layer of the structure that is to be
`formed:
`0016 1. Selectively depositing at least one material by
`electrodeposition upon one or more desired regions of
`a Substrate.
`0017 2. Then, blanket depositing at least one addi
`tional material by electrodeposition so that the addi
`tional deposit covers both the regions that were previ
`ously selectively deposited onto, and the regions of the
`Substrate that did not receive any previously applied
`Selective depositions.
`0018 3. Finally, planarizing the materials deposited
`during the first and second operations to produce a
`smoothed surface of a first layer of desired thickness
`having at least one region containing the at least one
`material and at least one region containing at least the
`one additional material.
`0019. After formation of the first layer, one or more
`additional layers may be formed adjacent to the immediately
`preceding layer and adhered to the Smoothed Surface of that
`preceding layer. These additional layers are formed by
`repeating the first through third operations one or more times
`wherein the formation of each subsequent layer treats the
`previously formed layers and the initial Substrate as a new
`and thickening Substrate.
`0020. Once the formation of all layers has been com
`pleted, at least a portion of at least one of the materials
`
`deposited is generally removed by an etching process to
`expose or release the three-dimensional structure that was
`intended to be formed.
`0021. The preferred method of performing the selective
`electrodeposition involved in the first operation is by con
`formable contact mask plating. In this type of plating, one or
`more conformable contact (CC) masks are first formed. The
`CC masks include a Support structure onto which a patterned
`conformable dielectric material is adhered or formed. The
`conformable material for each mask is shaped in accordance
`with a particular cross-section of material to be plated. At
`least one CC mask is needed for each unique cross-sectional
`pattern that is to be plated.
`0022. The support for a CC mask is typically a plate-like
`structure formed of a metal that is to be selectively electro
`plated and from which material to be plated will be dis
`Solved. In this typical approach, the Support will act as an
`anode in an electroplating process. In an alternative
`approach, the Support may instead be a porous or otherwise
`perforated material through which deposition material will
`pass during an electroplating operation on its way from a
`distal anode to a deposition Surface. In either approach, it is
`possible for CC masks to share a common Support, i.e. the
`patterns of conformable dielectric material for plating mul
`tiple layers of material may be located in different areas of
`a single Support structure. When a single Support structure
`contains multiple plating patterns, the entire structure is
`referred to as the CC mask while the individual plating
`masks may be referred to as “submasks”. In the present
`application Such a distinction will be made only when
`relevant to a specific point being made.
`0023. In preparation for performing the selective depo
`sition of the first operation, the conformable portion of the
`CC mask is placed in registration with and pressed against
`a selected portion of the substrate (or onto a previously
`formed layer or onto a previously deposited portion of a
`layer) on which deposition is to occur. The pressing together
`of the CC mask and substrate occur in such a way that all
`openings, in the conformable portions of the CC mask
`contain plating Solution. The conformable material of the
`CC mask that contacts the Substrate acts as a barrier to
`electrodeposition while the openings in the CC mask that are
`filled with electroplating solution act as pathways for trans
`ferring material from an anode (e.g. the CC mask Support)
`to the non-contacted portions of the Substrate (which act as
`a cathode during the plating operation) when an appropriate
`potential and/or current are Supplied.
`0024. An example of a CC mask and CC mask plating are
`shown in FIGS. 1A-1C. F.G. 1A shows a side view of a CC
`mask 8 consisting of a conformable or deformable (e.g.
`elastomeric) insulator 10 patterned on an anode 12. The
`anode has two functions. One is as a Supporting material for
`the patterned insulator 10 to maintain its integrity and
`alignment since the pattern may be topologically complex
`(e.g., involving isolated “islands' of insulator material). The
`other function is as an anode for the electroplating operation.
`FIG. 1A also depicts a substrate 6 separated from mask 8.
`CC mask plating selectively deposits material 22 onto a
`Substrate 6 by simply pressing the insulator against the
`Substrate then electrodepositing material through apertures
`26a and 26b in the insulator as shown in FIG. 1B. After
`deposition, the CC mask is separated, preferably non-de
`
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`structively, from the substrate 6 as shown in FIG. 1C. The
`CC mask plating process is distinct from a “through-mask'
`plating process in that in a through-mask plating process the
`separation of the masking material from the Substrate would
`occur destructively. As with through-mask plating, CC mask
`plating deposits material selectively and simultaneously
`over the entire layer. The plated region may consist of one
`or more isolated plating regions where these isolated plating
`regions may belong to a single structure that is being formed
`or may belong to multiple structures that are being formed
`simultaneously. In CC mask plating, as individual masks are
`not intentionally destroyed in the removal process, they may
`be usable in multiple plating operations.
`0025. Another example of a CC mask and CC mask
`plating is shown in FIGS. 1D-1G. FIG. 1D shows an anode
`12' separated from a mask 8' that includes a patterned
`conformable material 10' and a support structure 20. FIG.
`1D also depicts substrate 6 separated from the mask 8. FIG.
`1E illustrates the mask 8' being brought into contact with the
`substrate 6. FIG. 1F illustrates the deposit 22 that results
`from conducting a current from the anode 12" to the substrate
`6. FIG. 1G illustrates the deposit 22 on substrate 6 after
`separation from mask 8. In this example, an appropriate
`electrolyte is located between the substrate 6 and the anode
`12' and a current of ions coming from one or both of the
`Solution and the anode are conducted through the opening in
`the mask to the substrate where material is deposited. This
`type of mask may be referred to as an anodeless INSTANT
`MASKTM (AIM) or as an anodeless conformable contact
`(ACC) mask.
`0026. Unlike through-mask plating, CC mask plating
`allows CC masks to be formed completely separate from the
`fabrication of the Substrate on which plating is to occur (e.g.
`separate from a three-dimensional (3D) structure that is
`being formed). CC masks may be formed in a variety of
`ways, for example, a photolithographic process may be
`used. All masks can be generated simultaneously prior to
`structure fabrication rather than during it. This separation
`makes possible a simple, low-cost, automated, self-con
`tained, and internally-clean "desktop factory” that can be
`installed almost anywhere to fabricate 3D structures, leaving
`any required clean room processes, such as photolithogra
`phy to be performed by service bureaus or the like.
`0027. An example of the electrochemical fabrication pro
`cess discussed above is illustrated in FIGS. 2A-2F. These
`figures show that the process involves deposition of a first
`material 2 which is a sacrificial material and a second
`material 4 which is a structural material. The CC mask 8, in
`this example, includes a patterned conformable material
`(e.g. an elastomeric dielectric material) 10 and a Support 12
`which is made from deposition material 2. The conformal
`portion of the CC mask is pressed against substrate 6 with
`a plating solution 14 located within the openings 16 in the
`conformable material 10. An electric current, from power
`Supply 18, is then passed through the plating solution 14 via
`(a) Support 12 which doubles as an anode and (b) Substrate
`6 which doubles as a cathode. FIG. 2A, illustrates that the
`passing of current causes material 2 within the plating
`solution and material 2 from the anode 12 to be selectively
`transferred to and plated on the substrate 6. After electro
`plating the first deposition material 2 onto the substrate 6
`using CC mask 8, the CC mask 8 is removed as shown in
`FIG. 2B. FIG. 2C depicts the second deposition material 4
`
`as having been blanket-deposited (i.e. non-selectively
`deposited) over the previously deposited first deposition
`material 2 as well as over the other portions of the substrate
`6. The blanket deposition occurs by electroplating from an
`anode (not shown), composed of the second material,
`through an appropriate plating solution (not shown), and to
`the cathode? substrate 6. The entire two-material layer is then
`planarized to achieve precise thickness and flatness as
`shown in FIG. 2D. After repetition of this process for all
`layers, the multi-layer structure 20 formed of the second
`material 4 (i.e. structural material) is embedded in first
`material 2 (i.e. sacrificial material) as shown in FIG. 2E.
`The embedded structure is etched to yield the desired device,
`i.e. structure 20, as shown in FIG. 2F.
`0028. Various components of an exemplary manual elec
`trochemical fabrication system 32 are shown in FIGS.
`3A-3C. The system 32 consists of several subsystems 34,
`36, 38, and 40. The substrate holding subsystem 34 is
`depicted in the upper portions of each of FIGS. 3A-3C and
`includes several components: (1) a carrier 48, (2) a metal
`substrate 6 onto which the layers are deposited, and (3) a
`linear slide 42 capable of moving the substrate 6 up and
`down relative to the carrier 48 in response to drive force
`from actuator 44. Subsystem 34 also includes an indicator 46
`for measuring differences in vertical position of the substrate
`which may be used in setting or determining layer thick
`nesses and/or deposition thicknesses. The Subsystem 34
`further includes feet 68 for carrier 48 which can be precisely
`mounted on subsystem 36.
`0029. The CC mask subsystem 36 shown in the lower
`portion of FIG. 3A includes several components: (1) a CC
`mask 8 that is actually made up of a number of CC masks
`(i.e. Submasks) that share a common Support/anode 12, (2)
`precision X-stage 54, (3) precision Y-stage 56, (4) frame 72
`on which the feet 68 of subsystem 34 can mount, and (5) a
`tank 58 for containing the electrolyte 16. Subsystems 34 and
`36 also include appropriate electrical connections (not
`shown) for connecting to an appropriate power source (not
`shown) for driving the CC masking process.
`0030 The blanket deposition subsystem 38 is shown in
`the lower portion of FIG. 3B and includes several compo
`nents: (1) an anode 62, (2) an electrolyte tank 64 for holding
`plating solution 66, and (3) frame 74 on which feet 68 of
`subsystem 34 may sit. Subsystem 38 also includes appro
`priate electrical connections (not shown) for connecting the
`anode to an appropriate power Supply (not shown) for
`driving the blanket deposition process.
`0031. The planarization subsystem 40 is shown in the
`lower portion of FIG. 3C and includes a lapping plate 52
`and associated motion and control systems (not shown) for
`planarizing the depositions.
`0032. In addition to teaching the use of CC masks for
`electrodeposition purposes, the 630 patent also teaches that
`the CC masks may be placed against a Substrate with the
`polarity of the voltage reversed and material may thereby be
`selectively removed from the substrate. It indicates that such
`removal processes can be used to selectively etch, engrave,
`and polish a substrate, e.g., a plaque.
`0033. Another method for forming microstructures from
`electroplated metals (i.e. using electrochemical fabrication
`techniques) is taught in U.S. Pat. No. 5,190,637 to Henry
`
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`
`Guckel, entitled “Formation of Microstructures by Multiple
`Level Deep X-ray Lithography with Sacrificial Metal lay
`ers’. This patent teaches the formation of metal structure
`utilizing mask exposures. A first layer of a primary metal is
`electroplated onto an exposed plating base to fill a void in a
`photoresist, the photoresist is then removed and a secondary
`metal is electroplated over the first layer and over the plating
`base. The exposed surface of the secondary metal is then
`machined down to a height which exposes the first metal to
`produce a flat uniform Surface extending across the both the
`primary and secondary metals. Formation of a second layer
`may then begin by applying a photoresist layer over the first
`layer and then repeating the process used to produce the first
`layer. The process is then repeated until the entire structure
`is formed and the secondary metal is removed by etching.
`The photoresist is formed over the plating base or previous
`layer by casting and the Voids in the photoresist are formed
`by exposure of the photoresist through a patterned mask via
`X-rays or UV radiation.
`0034 Electrochemical fabrication provides the ability to
`form prototypes and commerci