U.S. patent application number 13/426857 was filed with the patent office on 2013-09-26 for method for manufacturing fine-pitch bumps and structure thereof.
This patent application is currently assigned to CHIPBOND TECHNOLOGY CORPORATION. The applicant listed for this patent is Hua-An Dai, Yung-Wei Hsieh, Cheng-Fan Lin, Shu-Chen Lin, Cheng-Hung Shih. Invention is credited to Hua-An Dai, Yung-Wei Hsieh, Cheng-Fan Lin, Shu-Chen Lin, Cheng-Hung Shih.
Application Number | 20130249081 13/426857 |
Document ID | / |
Family ID | 49084087 |
Filed Date | 2013-09-26 |
United States Patent
Application |
20130249081 |
Kind Code |
A1 |
Shih; Cheng-Hung ; et
al. |
September 26, 2013 |
METHOD FOR MANUFACTURING FINE-PITCH BUMPS AND STRUCTURE THEREOF
Abstract
A method for manufacturing fine-pitch bumps comprises providing
a silicon substrate; forming a titanium-containing metal layer
having a plurality of first zones and a plurality of second zones
on the silicon substrate; forming a photoresist layer on the
titanium-containing metal layer; patterning the photoresist layer;
forming a plurality of copper bumps having a plurality of first top
surfaces and a plurality of first ring surfaces; heating the
photoresist layer to form a plurality of body portions and
removable portions; etching the photoresist layer; forming a
plurality of bump protection layers on the titanium-containing
metal layer, the first top surface and the first ring surface, each
of the bump protection layers comprises a bump coverage portion;
plating a plurality of gold layers at the bump coverage portion;
eventually, removing the second zones to enable each of the first
zones to form an under bump metallurgy layer.
Inventors: |
Shih; Cheng-Hung; (Changhua
County, TW) ; Hsieh; Yung-Wei; (Hsinchu City, TW)
; Lin; Shu-Chen; (Pingtung County, TW) ; Lin;
Cheng-Fan; (Hsinchu County, TW) ; Dai; Hua-An;
(Kaohsiung City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shih; Cheng-Hung
Hsieh; Yung-Wei
Lin; Shu-Chen
Lin; Cheng-Fan
Dai; Hua-An |
Changhua County
Hsinchu City
Pingtung County
Hsinchu County
Kaohsiung City |
|
TW
TW
TW
TW
TW |
|
|
Assignee: |
CHIPBOND TECHNOLOGY
CORPORATION
Hsinchu
TW
|
Family ID: |
49084087 |
Appl. No.: |
13/426857 |
Filed: |
March 22, 2012 |
Current U.S.
Class: |
257/737 ;
257/E21.589; 257/E23.021; 438/614 |
Current CPC
Class: |
H01L 24/03 20130101;
H01L 24/11 20130101; H01L 2224/05099 20130101; H01L 2224/034
20130101; H01L 2224/05666 20130101; H01L 2224/13147 20130101; H01L
2224/11906 20130101; H01L 2224/13564 20130101; H01L 2924/00013
20130101; H01L 2224/11472 20130101; H01L 2224/1147 20130101; H01L
2224/13644 20130101; H01L 24/05 20130101; H01L 2224/13655 20130101;
H01L 2224/13562 20130101; H01L 2924/00013 20130101; H01L 2224/13655
20130101; H01L 2224/05099 20130101; H01L 2224/13147 20130101; H01L
23/58 20130101; H01L 23/49811 20130101; H01L 2924/00014 20130101;
H01L 2224/13644 20130101; H01L 2924/00014 20130101; H01L 2924/00014
20130101; H01L 2224/13099 20130101; H01L 2224/05599 20130101; H01L
2224/05099 20130101; H01L 2924/00014 20130101; H01L 2924/00014
20130101; H01L 2924/00014 20130101; H01L 2924/00014 20130101; H01L
2924/00014 20130101; H01L 2924/00014 20130101; H01L 2224/05552
20130101; H01L 2224/05022 20130101; H01L 2224/13583 20130101; H01L
24/13 20130101; H01L 2224/0401 20130101; H01L 2224/05572 20130101;
H01L 2224/05666 20130101; H01L 2924/00014 20130101; H01L 2224/13664
20130101; H01L 2224/034 20130101; H01L 2924/00013 20130101; H01L
2224/03912 20130101; H01L 2224/13582 20130101; H01L 2224/13082
20130101; H01L 2224/05572 20130101; H01L 2224/13664 20130101; H01L
2924/00013 20130101 |
Class at
Publication: |
257/737 ;
438/614; 257/E23.021; 257/E21.589 |
International
Class: |
H01L 23/485 20060101
H01L023/485; H01L 21/768 20060101 H01L021/768 |
Claims
1. A method for manufacturing fine-pitch bumps at least comprising:
providing a silicon substrate having a surface, a plurality of bond
pads disposed at the surface and a protective layer disposed at the
surface, wherein the protective layer comprises a plurality of
openings, and the bond pads are revealed by the openings; forming a
titanium-containing metal layer on the protective layer and the
bond pads, the titanium-containing metal layer comprises a
plurality of first zones and a plurality of second zones located
outside the first zones; forming a photoresist layer on the
titanium-containing metal layer; patterning the photoresist layer
to form a plurality of opening slots corresponded to the first
zones of the titanium-containing metal layer; forming a plurality
of copper bumps at the first zones of the titanium-containing metal
layer, each of the copper bumps comprises a first top surface and a
first ring surface; heating the photoresist layer to ream the
opening slots of the photoresist layer, and the heat process
enables the photoresist layer to form a plurality of body portions
and a plurality of removable portions; etching the photoresist
layer to remove the removable portions and reveal the
titanium-containing metal layer, each of the body portions
comprises an inner lateral surface; forming a plurality of bump
protection layers on the titanium-containing metal layer, the first
top surface and the first ring surface of each of the copper bumps,
wherein each of the bump protection layers comprises a metallic
coverage portion and a bump coverage portion, the bump coverage
portion comprises a second top surface and a second ring surface,
the first top surface and the first ring surface of each of the
copper bumps are covered with each of the bump coverage portions,
and the second ring surface and the inner lateral surface of each
of the body portions are spaced apart from each other to define a
gap; plating a plurality of gold layers at each of the gaps, the
second top surface and the second ring surface of each of the bump
coverage portions, and each of the gold layers comprises a third
top surface; removing the body portions of the photoresist layer;
and removing the second zones of the titanium-containing metal
layer to enable each of the first zones of the titanium-containing
metal layer to form an under bump metallurgy layer located under
each of the copper bumps, each of the under bump metallurgy layers
comprises a bearing portion located under each of the copper bumps
and an extending portion protruded to the first ring surface of
each of the copper bumps, and the extending portion of each of the
under bump metallurgy layers is covered with the metallic coverage
portion of each of the bump protection layers.
2. The method for manufacturing fine-pitch bumps in accordance with
claim 1, wherein the method for etching the photoresist layer can
be a method of plasma dry etching.
3. The method for manufacturing fine-pitch bumps in accordance with
claim 1 further comprises a step of forming a plurality of wettable
layers on the third top surfaces of the gold layers prior to the
step of removing the body portions of the photoresist layer.
4. The method for manufacturing fine-pitch bumps in accordance with
claim 1, wherein each of the metallic coverage portions is
protruded to the second ring surface of the bump coverage portion
and comprises a first outer lateral surface.
5. The method for manufacturing fine-pitch bumps in accordance with
claim 4, wherein each of the gold layers further comprises a second
outer lateral surface coplanar with the first outer lateral surface
of each of the metallic coverage portions.
6. The method for manufacturing fine-pitch bumps in accordance with
claim 4, wherein the extending portion of each of the under bump
metallurgy layers comprises a third outer lateral surface coplanar
with the first outer lateral surface of each of the metallic
coverage portions.
7. The method for manufacturing fine-pitch bumps in accordance with
claim 1, wherein a glass transition temperature in the heat process
ranges from 70 to 140 degrees.
8-12. (canceled)
Description
FIELD OF THE INVENTION
[0001] The present invention is generally related to a method for
manufacturing fine-pitch bumps, which particularly relates to the
method for manufacturing fine-pitch bumps that prevents the copper
ions from dissociation.
BACKGROUND OF THE INVENTION
[0002] In structure of fine-pitch bumps, a short phenomenon is
easily occurred by a relatively short spacing between two adjacent
copper bumps owing to the copper ion dissociated from the copper
bump.
SUMMARY
[0003] The primary object of the present invention is to provide a
method for manufacturing fine-pitch bumps comprising the following
steps of providing a silicon substrate having a surface, a
plurality of bond pads disposed at the surface and a protective
layer disposed at the surface, wherein the protective layer
comprises a plurality of openings, and the bond pads are revealed
by the openings; forming a titanium-containing metal layer on the
protective layer and the bond pads, the titanium-containing metal
layer comprises a plurality of first zones and a plurality of
second zones located outside the first zones; forming a photoresist
layer on the titanium-containing metal layer; patterning the
photoresist layer to form a plurality of opening slots corresponded
to the first zones of the titanium-containing metal layer; forming
a plurality of copper bumps at the first zones of the
titanium-containing metal layer, each of the copper bumps comprises
a first top surface and a first ring surface; heating the
photoresist layer to ream the opening slots of the photoresist
layer, and the heat process enables the photoresist layer to form a
plurality of body portions and a plurality of removable portions;
etching the photoresist layer to remove the removable portions and
to reveal the titanium-containing metal layer, and each of the body
portions comprises an inner lateral surface; forming a plurality of
bump protection layers on the titanium-containing metal layer, the
first top surface and the first ring surface of each of the copper
bumps, wherein each of the bump protection layers comprises a
metallic coverage portion and a bump coverage portion, the bump
coverage portion comprises a second top surface and a second ring
surface, the first top surface and the first ring surface of each
of the copper bumps are covered with the bump coverage portion, the
inner lateral surface of each of the body portions and the second
ring surface are spaced apart from each other to define a gap;
plating a plurality of gold layers at each of the gaps, the second
top surface and the second ring surface of each of the bump
coverage portions, and each of the gold layers comprises a third
top surface; eventually, removing the body portions of the
photoresist layer; removing the second zones of the
titanium-containing metal layer to enable each of the first zones
of the titanium-containing metal layer to form an under bump
metallurgy layer located under each of the copper bumps, each of
the under bump metallurgy layers comprises a bearing portion
located under each of the copper bumps and an extending portion
protruded to the first ring surface of each of the copper bumps,
and the extending portion of each of the under bump metallurgy
layers is covered with the metallic coverage portion of each of the
bump protection layers. The bump protection layers and the gold
layers being formed on the titanium-containing metal layer, the
first top surface and the first ring surface of each of the copper
bumps may prevent the copper ions within the copper bumps from
dissociation to avoid a short phenomenon, which improves
reliability of the fine-pitch bump structure effectively.
DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a flow illustrating a method for manufacturing
fine-pitch bumps in accordance with a preferred embodiment of the
present invention.
[0005] FIGS. 2A to 2L are sectional schematic diagrams illustrating
a method for manufacturing fine-pitch bumps in accordance with a
preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0006] With reference to FIGS. 1 and 2A to 2L, a method for
manufacturing fine-pitch bumps in accordance with a preferred
embodiment of the present invention comprises the following steps
of: first, with reference to step 11 of FIG. 1 and FIG. 2A,
providing a silicon substrate 110 having a surface 111, a plurality
of bond pads 112 disposed at the surface 111 and a protective layer
113 disposed at the surface 111, wherein the protective layer 113
comprises a plurality of openings 113a, and the bond pads 112 are
revealed by the openings 113a; next, referring to step 12 of FIG. 1
and FIG. 2B, forming a titanium-containing metal layer 200 on the
protective layer 113 and the bond pads 112, the titanium-containing
metal layer 200 comprises a plurality of first zones 210 and a
plurality of second zones 220 located outside the first zones 210;
thereafter, referring to step 13 of FIG. 1 and FIG. 2C, forming a
photoresist layer 300 on the titanium-containing metal layer 200;
afterwards, referring to step 14 of FIG. 1 and FIG. 2D, patterning
the photoresist layer 300 to form a plurality of opening slots 310
corresponded to the first zones 210 of the titanium-containing
metal layer 200; then, referring to step 15 of FIG. 1 and FIG. 2E,
forming a plurality of copper bumps 120 at the first zones 210 of
the titanium-containing metal layer 200, each of the copper bumps
120 comprises a first top surface 121 and a first ring surface 122;
next, referring to step 16 of FIG. 1 and FIG. 2F, heating the
photoresist layer 300 to ream the opening slots 310 of the
photoresist layer 300, and the heat process enables the photoresist
layer 300 to form a plurality of body portions 320 and a plurality
of removable portions 330, in this embodiment, the glass transition
temperature in the heat process ranges from 70 to 140 degrees.
[0007] Next, referring to step 17 of FIG. 1 and FIG. 2G, etching
the photoresist layer 300 to remove the removable portions 330 and
reveal the titanium-containing metal layer 200, and each of the
body portions 320 comprises an inner lateral surface 321, in this
embodiment, the method for etching the photoresist layer 300 can be
a method of plasma dry etching; thereafter, with reference to step
18 of FIG. 1 and FIG. 2H, forming a plurality of bump protection
layers 130 on the titanium-containing metal layer 200, the first
top surface 121 and the first ring surface 122 of each of the
copper bumps 120, wherein each of the bump protection layers 130
comprises a metallic coverage portion 132 and a bump coverage
portion 131, the bump coverage portion 131 comprises a second top
surface 131a and a second ring surface 131b, the first top surface
121 and the first ring surface 122 of each of the copper bumps 120
are covered with the bump coverage portion 131, in this embodiment,
the material of the bump protection layers 130 can be chosen from
one of nickel, palladium or gold, the metallic coverage portion 132
is protruded to the second ring surface 131b of the bump coverage
portion 131 and comprises a first outer lateral surface 132a,
wherein the inner lateral surface 321 of each of the body portions
320 and the second ring surface 131b are spaced apart from each
other to define a gap S; next, with reference to step 19 of FIG. 1
and FIG. 2I, plating a plurality of gold layers 140 at each of the
gaps S, the second top surface 131a and the second ring surface
131b of each of the bump coverage portions 131, wherein each of the
gold layers 140 comprises a third top surface 141 and a second
outer lateral surface 142; afterward, referring to step 20 of FIG.
1 and FIG. 2J, forming a plurality of wettable layers 150 on the
third top surfaces 141 of the gold layers 140.
[0008] Next, referring to step 21 of FIG. 1 and FIG. 2K, removing
the body portions 320 of the photoresist layer 300 to reveal the
second zones 220 of the titanium-containing metal layer 200, the
second outer lateral surfaces 142 of the gold layers 140, the
wettable layers 150 and the first outer lateral surfaces 132a of
the metallic coverage portions 132, in this invention, the second
outer lateral surface 142 of each of the gold layers 140 is
coplanar with the first outer lateral surface 132a of each of the
metallic coverage portions 132; eventually, referring to step 22 of
FIG. 1 and FIG. 2L, removing the second zones 220 of the
titanium-containing metal layer 200 to enable each of the first
zones 210 of the titanium-containing metal layer 200 to form an
under bump metallurgy layer 160 located under each of the copper
bumps 120, wherein each of the under bump metallurgy layers 160
comprises a bearing portion 161 located under each of the copper
bumps 120 and an extending portion 162 protruded to the first ring
surface 122 of each of the copper bumps 120, and the under bump
metallurgy layers 160 are made of a material selected from one of
titanium/tungsten/gold, titanium/copper and
titanium/tungsten/copper. The extending portion 162 of each of the
under bump metallurgy layers 160 is covered with the metallic
coverage portion 132 of each of the bump protection layer 130, and
the extending portion 162 of each of the under bump metallurgy
layers 160 comprises a third outer lateral surface 162a coplanar
with the first outer lateral surface 132a of each of the metallic
coverage portions 132. The bump protection layers 130 and the gold
layers 140 being formed on the titanium-containing metal layer 200,
the first top surface 121 and the first ring surface 122 of each of
the copper bumps 120 may prevent the copper ions within the copper
bumps 120 from dissociation to avoid a short phenomenon, which
improves reliability for the fine-pitch bump structure.
[0009] With reference to FIG. 2L again, a fine-pitch bump structure
100 in accordance with a preferred embodiment of the present
invention at least comprises a silicon substrate 110, a plurality
of under bump metallurgy layers 160, a plurality of copper bumps
120, a plurality of bump protection layers 130, a plurality of gold
layers 140, and a plurality of wettable layers 150, wherein the
silicon substrate 110 comprises a surface 111, a plurality of bond
pads 112 disposed at the surface 111 and a protective layer 113
disposed at the surface 111. The protective layer 113 comprises a
plurality of openings 113a, and the bond pads 112 are revealed by
the openings 113a. The under bump metallurgy layers 160 are formed
on the bond pads 112, each of the under bump metallurgy layers 160
comprises a bearing portion 161 and an extending portion 162, and
the under bump metallurgy layers 160 are made of a material
selected from one of titanium/tungsten/gold, titanium/copper and
titanium/tungsten/copper. The copper bumps 120 are formed on the
under bump metallurgy layers 160, and each of the copper bumps 120
comprises a first top surface 121 and a first ring surface 122. The
bearing portion 161 of each of the under bump metallurgy layers 160
is located under each of the copper bumps 120, and the extending
portion 162 of each of the under bump metallurgy layers 160 is
protruded to the first ring surface 122 of each of the copper bumps
120. The bump protection layers 130 are formed on the extending
portions 162 of the under bump metallurgy layers 160, the first top
surface 121 and the first ring surface 122 of each of the copper
bumps 120. Each of the bump protection layers 130 comprises a bump
coverage portion 131 and a metallic coverage portion 132, wherein
the bump coverage portion 131 comprises a second top surface 131a
and a second ring surface 131b, and each of the metallic coverage
portions 132 is protruded to the second ring surface 131b of the
bump coverage portion 131 and comprises a first outer lateral
surface 132a. The first top surface 121 and the first ring surface
122 of each of the copper bumps 120 are covered with each of the
bump coverage portions 131, each of the extending portions 162 is
covered with each of the metallic coverage portions 132, and the
material of the bump protection layers 130 can be chosen from one
of nickel, palladium or gold. The gold layers 140 are formed on
each of the metallic coverage portions 132, the second top surface
131a and the second ring surface 131b of each of the bump coverage
portions 131, wherein each of the gold layers 140 comprises a third
top surface 141 and a second outer lateral surface 142 coplanar
with the first outer lateral surface 132a of each of the metallic
coverage portions 132. The wettable layers 150 are formed on the
third top surfaces 141 of the gold layers 140. In this embodiment,
the extending portion 162 of each of the under bump metallurgy
layers 160 comprises a third outer lateral surface 162a coplanar
with the first outer lateral surface 132a of each of the metallic
coverage portions 132.
[0010] While this invention has been particularly illustrated and
described in detail with respect to the preferred embodiments
thereof, it will be clearly understood by those skilled in the art
that it is not limited to the specific features and describes and
various modifications and changes in form and details may be made
without departing from the spirit and scope of this invention.
* * * * *