A process is presented for patterning vias into thick amorphous fluoropolymer layers for a novel In bump fabrication process, achieved using a hot embossing technique. The technique uses a patterned Si stamp that employs a two-step etching process to obtain pillars with a controlled positive sidewall angle. After embossing with the Si stamp, vias are formed in amorphous fluoropolymer layers. A postembossing blanket reactive ion etch step is then used to remove excess fluoropolymer from the bottoms of the vias, exposing a Ni film. Successful electroplating of In bumps into vias initiated at the Ni layer is demonstrated, confirming complete removal of excess fluoropolymer.

1.
A.
Rogalski
,
J.
Antoszewski
, and
L.
Faraone
,
J. Appl. Phys.
105
,
091101
(
2009
).
2.
A.
Hoffman
,
Laser Focus World
42
,
81
(
2006
).
3.
L.
Melkonian
,
J.
Bangs
,
L.
Elizondo
,
R.
Ramey
, and
E.
Guerrero
,
Proc. SPIE
7660
,
76602W
(
2010
).
4.
B.
Dang
 et al,
Elec. Comp. C.
58
,
1505
(
2008
).
5.
A. C.
Moore
and
D.
Tabor
,
Br. J. Appl. Phys.
3
,
299
(
1952
).
6.
T.
Umeda
,
D.
Kumaki
, and
S.
Tokito
,
Org. Electron.
9
,
545
(
2008
).
7.
A.
Datta
 et al,
IEEE Sens. J.
3
,
788
(
2003
).
8.
R.
Chow
,
G. E.
Loomis
, and
R. L.
Ward
,
J. Vac. Sci. Technol. A
14
,
63
(
1996
).
9.
R. W.
Jaszewski
,
H.
Schift
,
P.
Gröning
, and
G.
Margaritondo
,
Microelectron. Eng.
35
,
381
(
1997
).
10.
T. E. F. M.
Standaert
 et al,
J. Vac. Sci. Technol. A
19
,
435
(
2001
).
11.
T.
Ono
,
T.
Akagi
, and
T.
Ichiki
,
J. Appl. Phys.
105
,
013314
(
2009
).
12.
13.
B.
Schwartz
and
H.
Robbins
,
J. Electrochem. Soc.
123
,
1903
(
1976
).
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