U.S. patent application number 16/016658 was filed with the patent office on 2019-12-26 for three-dimensional integrated circuit structures.
This patent application is currently assigned to Taiwan Semiconductor Manufacturing Co., Ltd.. The applicant listed for this patent is Taiwan Semiconductor Manufacturing Co., Ltd.. Invention is credited to Hsien-Wei Chen, Jie Chen, Ying-Ju Chen.
Application Number | 20190393159 16/016658 |
Document ID | / |
Family ID | 68766251 |
Filed Date | 2019-12-26 |
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United States Patent
Application |
20190393159 |
Kind Code |
A1 |
Chen; Jie ; et al. |
December 26, 2019 |
THREE-DIMENSIONAL INTEGRATED CIRCUIT STRUCTURES
Abstract
Three-dimensional integrated circuit (3DIC) structures are
disclosed. A 3DIC structure includes a first die and a second die
bonded to the first die. The first die includes a first integrated
circuit region and a first seal ring region around the first
integrated circuit region, and has a first alignment mark within
the first integrated circuit region. The second die includes a
second integrated circuit region and a second seal ring region
around the second integrated circuit region, and has a second
alignment mark within the second seal ring region and corresponding
to the first alignment mark.
Inventors: |
Chen; Jie; (New Taipei City,
TW) ; Chen; Hsien-Wei; (Hsinchu City, TW) ;
Chen; Ying-Ju; (Yunlin County, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Taiwan Semiconductor Manufacturing Co., Ltd. |
Hsinchu |
|
TW |
|
|
Assignee: |
Taiwan Semiconductor Manufacturing
Co., Ltd.
Hsinchu
TW
|
Family ID: |
68766251 |
Appl. No.: |
16/016658 |
Filed: |
June 25, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 23/544 20130101;
H01L 24/08 20130101; H01L 2224/05009 20130101; H01L 23/5226
20130101; H01L 2224/80132 20130101; H01L 2224/80905 20130101; H01L
2224/08146 20130101; H01L 2224/03462 20130101; H01L 2224/05546
20130101; H01L 2224/80896 20130101; H01L 2224/04 20130101; H01L
2224/05006 20130101; H01L 2224/80895 20130101; H01L 2224/0557
20130101; H01L 2224/08145 20130101; H01L 2224/8013 20130101; H01L
2224/03901 20130101; H01L 2225/06544 20130101; H01L 2224/034
20130101; H01L 2224/9202 20130101; H01L 2224/73201 20130101; H01L
23/585 20130101; H01L 23/528 20130101; H01L 2223/54426 20130101;
H01L 25/0657 20130101; H01L 24/05 20130101; H01L 2224/03616
20130101; H01L 2225/1041 20130101; H01L 2225/06524 20130101; H01L
24/73 20130101; H01L 24/80 20130101; H01L 2224/04105 20130101; H01L
24/20 20130101; H01L 24/03 20130101; H01L 2224/80905 20130101; H01L
2224/80895 20130101; H01L 2224/80896 20130101; H01L 2224/73201
20130101; H01L 2224/08 20130101; H01L 2224/20 20130101; H01L
2224/03462 20130101; H01L 2924/00014 20130101; H01L 2224/034
20130101; H01L 2924/00014 20130101; H01L 2224/03616 20130101; H01L
2924/00014 20130101; H01L 2224/03901 20130101; H01L 2224/03616
20130101; H01L 2224/03901 20130101; H01L 2224/034 20130101; H01L
2224/03901 20130101; H01L 2224/034 20130101; H01L 2224/03616
20130101; H01L 2224/04 20130101; H01L 2224/08 20130101 |
International
Class: |
H01L 23/544 20060101
H01L023/544; H01L 23/522 20060101 H01L023/522; H01L 25/065 20060101
H01L025/065; H01L 23/528 20060101 H01L023/528 |
Claims
1. A three-dimensional integrated circuit structure, comprising: a
first die comprising a first integrated circuit region, a first
seal ring region around the first integrated circuit region, and a
first alignment mark within the first integrated circuit region;
and a second die bonded to the first die, comprising a second
integrated circuit region, a second seal ring region around the
second integrated circuit region, and a second alignment mark
within the second seal ring region and corresponding to the first
alignment mark.
2. The three-dimensional integrated circuit structure of claim 1,
wherein the first alignment mark is within the second seal ring
region from a top view.
3. The three-dimensional integrated circuit structure of claim 1,
wherein the first die further comprises a plurality of first seal
ring patterns within the first seal ring region and outside of the
second seal ring region from a top view.
4. The three-dimensional integrated circuit structure of claim 1,
wherein the second die further comprises a plurality of second seal
ring patterns within the second seal ring region and surrounding
the second alignment mark.
5. The three-dimensional integrated circuit structure of claim 1,
wherein the first die further has a first interconnect structure,
and a first top metal feature of the first interconnect structure
is at a level substantially the same as that of the first alignment
mark.
6. The three-dimensional integrated circuit structure of claim 1,
wherein the second die further has a second interconnect structure,
and a second top metal feature of the second interconnect structure
is at a level substantially the same as that of the second
alignment mark.
7. The three-dimensional integrated circuit structure of claim 1,
wherein each of the first alignment mark and the second alignment
mark is square, rectangular, polygonal, round, elliptical,
strip-shaped, T-shaped, L-shaped, box-shaped or cross-shaped.
8. The three-dimensional integrated circuit structure of claim 1,
wherein the second die is bonded to the first die through a hybrid
bonding comprising a metal-to-metal bonding and a
dielectric-to-dielectric bonding.
9. (canceled)
10. (canceled)
11. (canceled)
12. (canceled)
13. (canceled)
14. (canceled)
15. (canceled)
16. (canceled)
17. (canceled)
18. (canceled)
19. (canceled)
20. (canceled)
21. The three-dimensional integrated circuit structure of claim 3,
wherein the first alignment mark and the first seal ring patterns
are at substantially the same level.
22. The three-dimensional integrated circuit structure of claim 4,
wherein the second alignment mark and the second seal ring patterns
are at substantially the same level.
23. The three-dimensional integrated circuit structure of claim 1,
wherein the first die further comprises a first semiconductor
substrate, a first interconnect structure over the first
semiconductor substrate, and the first alignment mark is over the
first semiconductor substrate and aside the first interconnect
structure.
24. The three-dimensional integrated circuit structure of claim 23,
wherein the first die further comprises a first bonding structure
over the first interconnect structure, and the first bonding
structure comprises a plurality of first bonding features embedded
by at least one first bonding dielectric layer.
25. The three-dimensional integrated circuit structure of claim 1,
wherein the second die further comprises a second semiconductor
substrate, a second interconnect structure over the second
semiconductor substrate, and the second alignment mark is over the
second semiconductor substrate and aside the second interconnect
structure.
26. The three-dimensional integrated circuit structure of claim 25,
wherein the second die further comprises a second bonding structure
over the second interconnect structure, and the second bonding
structure comprises a plurality of second bonding features embedded
by at least one second bonding dielectric layer.
27. The three-dimensional integrated circuit structure of claim 1,
wherein the first alignment mark and the second alignment mark are
within a corner of the second seal ring region of the second die
from a top view.
28. The three-dimensional integrated circuit structure of claim 1,
further comprising a plurality of through dielectric vias over the
first die and surrounding the second die.
29. The three-dimensional integrated circuit structure of claim 28,
further comprising a redistribution layer structure over the second
die and electrically connected to the plurality of through
dielectric vias.
30. The three-dimensional integrated circuit structure of claim 1,
wherein from a top view, the first alignment mark comprises a shape
complementary of a shape of the second alignment mark.
31. A three-dimensional integrated circuit structure, comprising: a
first die comprising a first integrated circuit region, a first
seal ring region around the first integrated circuit region, and a
first alignment mark within the first integrated circuit region;
and a second die bonded to the first die, comprising a second
integrated circuit region, a second seal ring region around the
second integrated circuit region, and a second alignment mark
within the second seal ring region and corresponding to the first
alignment mark, wherein the first alignment mark is between metal
features of a first interconnect structure of the first die, and
the second alignment mark is outside of metal features of a second
interconnect structure of the second die.
32. A three-dimensional integrated circuit structure, comprising: a
first die comprising a first integrated circuit region, a first
seal ring region around the first integrated circuit region, and a
first alignment mark within the first integrated circuit region; a
second die bonded to the first die, comprising a second integrated
circuit region, a second seal ring region around the second
integrated circuit region, and a second alignment mark within the
second seal ring region and corresponding to the first alignment
mark; and a plurality of through dielectric vias over the first die
and surrounding the second die, wherein the first die further
comprises a plurality of first seal ring patterns at an outer side
of the through dielectric vias.
Description
BACKGROUND
[0001] In recent years, the semiconductor industry has experienced
rapid growth due to continuous improvement in integration density
of various electronic components, e.g., transistors, diodes,
resistors, capacitors, etc. For the most part, this improvement in
integration density has come from successive reductions in minimum
feature size, which allows more components to be integrated into a
given area.
[0002] These smaller electronic components also require smaller
packages that occupy less area than previous packages. Examples of
the type of packages for semiconductors include quad flat pack
(QFP), pin grid array (PGA), ball grid array (BGA), flip chips
(FC), three-dimensional integrated circuits (3DICs), wafer level
packages (WLPs), and package on package (PoP) devices. Some 3DICs
are prepared by placing chips over chips on a semiconductor wafer
level. The 3DICs provide improved integration density and other
advantages, such as faster speeds and higher bandwidth, because of
the decreased length of interconnects between the stacked chips.
However, there are many challenges related to 3DICs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a cross-sectional view of a 3DIC structure in
accordance with some embodiments.
[0004] FIG. 2 is a simplified top view of a 3DIC structure in
accordance with some embodiments.
[0005] FIG. 3 is an enlarged top view of the part A of FIG. 2.
[0006] FIG. 4 is a simplified top view of a 3DIC structure in
accordance with some embodiments.
[0007] FIG. 5 to FIG. 16 are top views of alignment marks of 3DIC
structures in accordance with some embodiments.
[0008] FIG. 17 is a cross-sectional view of a 3DIC structure in
accordance with alternative embodiments.
[0009] FIG. 18 is a simplified top view of a 3DIC structure in
accordance with alternative embodiments.
[0010] FIG. 19 is an enlarged top view of the part A of FIG.
18.
[0011] FIG. 20 is a simplified top view of a 3DIC structure in
accordance with alternative embodiments.
[0012] FIG. 21 to FIG. 22 are simplified top views of 3DIC
structures in accordance with yet alternative embodiments.
DETAILED DESCRIPTION
[0013] The following disclosure provides many different
embodiments, or examples, for implementing different features of
the provided subject matter. Specific examples of components and
arrangements are described below for the purposes of conveying the
present disclosure in a simplified manner. These are, of course,
merely examples and are not intended to be limiting. For example,
the formation of a second feature over or on a first feature in the
description that follows may include embodiments in which the
second and first features are formed in direct contact, and may
also include embodiments in which additional features may be formed
between the second and first features, such that the second and
first features may not be in direct contact. In addition, the same
reference numerals and/or letters may be used to refer to the same
or similar parts in the various examples the present disclosure.
The repeated use of the reference numerals is for the purpose of
simplicity and clarity and does not in itself dictate a
relationship between the various embodiments and/or configurations
discussed.
[0014] Further, spatially relative terms, such as "beneath",
"below", "lower", "on", "over", "overlying", "above", "upper" and
the like, may be used herein to facilitate the description of one
element or feature's relationship to another element(s) or
feature(s) as illustrated in the figures. The spatially relative
terms are intended to encompass different orientations of the
device in use or operation in addition to the orientation depicted
in the figures. The apparatus may be otherwise oriented (rotated 90
degrees or at other orientations) and the spatially relative
descriptors used herein may likewise be interpreted
accordingly.
[0015] FIG. 1 is a cross-sectional view of a 3DIC structure in
accordance with some embodiments. FIG. 2 is a simplified top view
of a 3DIC structure in accordance with some embodiments.
Specifically, FIG. 1 is a cross-sectional view taken along the line
I-I of FIG. 2. For simplicity and clarity of illustration, only few
elements such as first and second dies and first and second
alignment marks are shown in the simplified top view of FIG. 2, and
these elements are not necessarily in the same plane. FIG. 3 is an
enlarged top view of the part A of FIG. 2.
[0016] Referring to FIG. 1, a first die 100 is provided. The first
die 100 may be an application-specific integrated circuit (ASIC)
chip, an analog chip, a sensor chip, a wireless and radio frequency
chip, a voltage regulator chip or a memory chip, for example. In
some embodiments, the first die 100 may be an active component or a
passive component. In some embodiments, the first die 100 includes
a first semiconductor substrate 102, a first interconnect structure
104, a plurality of first seal ring patterns SP1, a first alignment
mark AM1 and a first bonding structure BS1.
[0017] In some embodiments, the first semiconductor substrate 102
includes an elementary semiconductor such as silicon or germanium
and/or a compound semiconductor such as silicon germanium, silicon
carbide, gallium arsenic, indium arsenide, gallium nitride or
indium phosphide. In some embodiments, the first semiconductor
substrate 102 is a semiconductor-on-insulator (SOI) substrate. In
various embodiments, the first semiconductor substrate 102 may take
the form of a planar substrate, a substrate with multiple fins,
nanowires, or other forms known to people having ordinary skill in
the art. Depending on the requirements of design, the first
semiconductor substrate 102 may be a P-type substrate or an N-type
substrate and may have doped regions therein. The doped regions may
be configured for an N-type device or a P-type device.
[0018] In some embodiments, the first semiconductor substrate 102
includes a first integrated circuit region 10 and a first seal ring
region 12 around or surrounding the first integrated circuit region
10. The first integrated circuit region 10 and the first seal ring
region 12 constitute a first die region or chip region of the first
die 100.
[0019] In some embodiments, the first semiconductor substrate 102
includes isolation structures defining at least one active area,
and a first device layer is disposed on/in the active area. The
first device layer includes a variety of devices. In some
embodiments, the devices include active components, passive
components, or a combination thereof. In some embodiments, the
devices may include integrated circuits devices. The devices are,
for example, transistors, capacitors, resistors, diodes,
photodiodes, fuse devices, or other similar devices. In some
embodiments, the first device layer includes a gate structure,
source/drain regions, spacers, and the like.
[0020] The first interconnect structure 104 is disposed over a
first side (e.g., front side) of the first semiconductor substrate
102. Specifically, the first interconnect structure 104 is disposed
over and electrically connected to the first device layer within
the first integrated circuit region 10. In some embodiments, the
first interconnect structure 104 includes at least one first
insulating layer 106 and a plurality of first metal features 108.
The first metal features 108 are disposed in the first insulating
layer 106 and electrically connected with each other. A portion of
the first metal features 108, such as first top metal features 108a
and 108b, are exposed by the first insulating layer 106. In some
embodiments, the first insulating layer 106 includes an inter-layer
dielectric (ILD) layer on the first semiconductor substrate 102,
and at least one inter-metal dielectric (IMD) layer over the
inter-layer dielectric layer. In some embodiments, the first
insulating layer 106 includes silicon oxide, silicon oxynitride,
silicon nitride, a low dielectric constant (low-k) material or a
combination thereof. The first insulating layer 106 may be a single
layer or a multiple-layer structure. In some embodiments, the first
metal features 108 include plugs and metal lines. The plugs may
include contacts formed in the inter-layer dielectric layer, and
vias formed in the inter-metal dielectric layer. The contacts are
formed between and in contact with a bottom metal line and the
underlying first device layer. The vias are formed between and in
contact with two metal lines. The first metal features 108 may
include tungsten (W), copper (Cu), a copper alloy, aluminum (Al),
an aluminum alloy or a combination thereof. In some embodiments, a
barrier layer may be disposed between the first metal features 108
and the first insulating layer 106 to prevent the material of the
first metal features 108 from migrating to the underlying first
device layer. The barrier layer includes Ta, TaN, Ti, TiN, CoW or a
combination thereof, for example. In some embodiments, the first
interconnect structure 104 is formed by a dual damascene process.
In alternative embodiments, the first interconnect structure 104 is
formed by multiple single damascene processes. In yet alternative
embodiments, the first interconnect structure 104 is formed by an
electroplating process.
[0021] The first seal ring patterns SP1 are disposed over the first
side (e.g., front side) of the first semiconductor substrate 102.
Specifically, the first seal ring patterns SP1 are disposed over
and electrically insulated from the first device layer, and located
aside the first interconnect structure 104 within the first seal
ring region 12. In some embodiments, the first seal ring patterns
SP1 have a grid-like shape, a strip shaped, a ring shape or any
suitable shape. In some embodiments, the first interconnect
structure 104 is arranged to form the first seal ring patterns SP1.
That is, the first seal ring patterns SP1 are formed during the
formation of the first interconnect structure 104.
[0022] Herein, when elements are described as "at substantially the
same level", the elements are formed at substantially the same
height in the same layer, or having the same positions embedded by
the same layer. In some embodiments, the elements at substantially
the same level are formed from the same material(s) with the same
process step(s). In some embodiments, the tops of the elements at
substantially the same level are substantially coplanar. For
example, as shown in FIG. 1, the first seal ring patterns SP1 are
at substantially the same level with the first interconnect
structure 104. Specifically, the top surfaces of the first seal
ring patterns SP1 are substantially coplanar with the top surfaces
of the first top metal features 108a and 108b of the first
interconnect structure 104.
[0023] The first alignment mark AM1 is disposed over the first side
(e.g., front side) of the first semiconductor substrate 102.
Specifically, the first alignment mark AM1 is disposed over and
electrically insulated from the first device layer, and located
between the first top metal features 108a and 108b of the first
interconnect structure 104 within the first integrated circuit
region 10. In some embodiments, the first alignment mark AM1 is at
a floating potential. In some embodiments, the first interconnect
structure 104 is arranged to form the first alignment mark AM1.
Specifically, the first alignment mark AM1 is formed during the
formation of the first top metal features 108a and 108b of the
first interconnect structure 104. In some embodiments, the first
alignment mark AM1 includes metal, such as copper. In some
embodiments, the first alignment mark AM1 is at substantially the
same level with the first top metal features 108a and 108b of the
first interconnect structure 104. Specifically, as shown in FIG. 1,
the top surface of the first alignment mark AM1 is substantially
coplanar with the top surfaces of the first top metal features 108a
and 108b of the first interconnect structure 104.
[0024] In some embodiments, the first alignment mark AM1 is square,
rectangular, polygonal, round, elliptical, strip-shaped, T-shaped,
L-shaped, box-shaped, cross-shaped or any suitable shape. For
example, the first alignment mark AM1 is designed as a square box
or square pattern, as shown in FIG. 2 and FIG. 3.
[0025] In some embodiments, an alignment mark is detected using an
imaging device mounted on an exposing apparatus, before the
exposing process of a resist layer for defining patterns is carried
out. In some embodiments, the alignment mark can be referred to an
overlay mark. Specifically, when two layers, elements or dies are
bonded with one another, the alignment marks of the two layers,
elements or dies can be inspected for overlay accuracy based on
whether the upper alignment mark and the lower alignment mark are
accurately aligned with each other. Therefore, the alignment mark
can function as an overlay mark. In some embodiments, the first
alignment mark AM1 is referred to as a first overlay mark
throughout the specification.
[0026] In some embodiments, multiple first alignment marks AM1 are
disposed in the first integrated circuit region 10. In some
embodiments, two first alignment marks AM1 are disposed in the
diagonal corners of the first integrated circuit region 10, as
shown in FIG. 2. In alternative embodiments, four first alignment
marks AM1 are disposed in the four corners of the first integrated
circuit region 10, as shown in FIG. 4.
[0027] The first bonding structure BS1 is disposed over the first
side (e.g., front side) of the first interconnect structure 104.
Specifically, the first bonding structure BS1 is disposed over the
first interconnect structure 104 within the first integrated
circuit region 10. In some embodiments, the first bonding structure
BS1 includes at least one first bonding dielectric layer BDL1 and a
plurality of first bonding metal features. In some embodiments, the
first bonding dielectric layer BDL1 includes silicon oxide, silicon
nitride, a polymer or a combination thereof. The first bonding
metal features are disposed in the first bonding dielectric layer
BDL1 and electrically connected with each other. In some
embodiments, the first bonding metal features include first bonding
vias BV1 electrically connected to the first interconnect structure
104 and first bonding pads BP1 electrically connected to the first
bonding vias BV1. The first bonding metal features may include
tungsten (W), copper (Cu), a copper alloy, aluminum (Al), an
aluminum alloy or a combination thereof. In some embodiments, a
barrier layer may be disposed between the first bonding metal
features and the first bonding dielectric layer BDL1. The barrier
layer includes Ta, TaN, Ti, TiN, CoW or a combination thereof, for
example. In some embodiments, the first bonding structure BS1 is
formed by a dual damascene process. In alternative embodiments, the
first bonding structure BS1 is formed by multiple single damascene
processes. In yet alternative embodiments, the first bonding
structure BS1 is formed by an electroplating process.
[0028] Still referring to FIG. 1, a second die 200 is provided. The
second die 200 may be an application-specific integrated circuit
(ASIC) chip, an analog chip, a sensor chip, a wireless and radio
frequency chip, a voltage regulator chip or a memory chip, for
example. The second die 200 and the first die 100 may be the same
type of dies or different types of dies. In some embodiments, the
second die 200 may be an active component or a passive component.
In some embodiments, the second die 200 is smaller than the first
die 100.
[0029] In some embodiments, the second die 200 is similar to the
second die 100. Similarly, the second die 200 includes a second
semiconductor substrate 202, a second interconnect structure 204, a
plurality of second seal ring patterns SP2, a second alignment mark
AM2 and a second bonding structure BS2. Thus, the difference
between the second die 200 and the first die 100 is illustrated in
details below and the similarity between them is not iterated
herein.
[0030] The second semiconductor substrate 202 is similar to the
first semiconductor substrate 102. Similarly, the second
semiconductor substrate 202 includes a second integrated circuit
region 20 and a second seal ring region 22 around or surrounding
the second integrated circuit region 20. The second integrated
circuit region 20 and the second seal ring region 22 constitute a
first die region or chip region of the second die 200.
[0031] The second interconnect structure 204 is similar to the
first interconnect structure 104. Similarly, the second
interconnect structure 204 is disposed over a first side (e.g.,
front side) of the second semiconductor substrate 202.
Specifically, the second interconnect structure 204 is disposed
over and electrically connected to the second device layer within
the second integrated circuit region 20. In some embodiments, the
second interconnect structure 204 includes at least one second
insulating layer 206 and a plurality of second metal features 208.
The second metal features 208 are disposed in the second insulating
layer 206 and electrically connected with each other. A portion of
the second metal features 208, such as second top metal features
208a, are exposed by the second insulating layer 206.
[0032] The second bonding structure BS2 is similar to the first
bonding structure BS1. Similarly, the second bonding structure BS2
is disposed over the first side (e.g., front side) of the second
interconnect structure 204. Specifically, the second bonding
structure BS2 is disposed over the second interconnect structure
204 within the second integrated circuit region 20. In some
embodiments, the second bonding structure BS2 includes at least one
second bonding dielectric layer BDL2 and a plurality of second
bonding metal features. The second bonding metal features are
disposed in the second bonding dielectric layer BDL2 and
electrically connected with each other. In some embodiments, the
second bonding metal features include second bonding vias BV2
electrically connected to the second interconnect structure 204 and
second bonding pads BP2 electrically connected to the second
bonding vias BV2.
[0033] The second seal ring patterns SP2 are similar to the first
seal ring patterns SP1. Similarly, the second seal ring patterns
SP2 are disposed over the first side (e.g., front side) of the
second semiconductor substrate 202. Specifically, the second seal
ring patterns SP2 are disposed over and electrically insulated from
the second device layer, and located aside the second interconnect
structure 204 within the second seal ring region 22. In some
embodiments, the second seal ring patterns SP2 have a grid-like
shape, a strip shaped, a ring shape or any suitable shape. In some
embodiments, the second interconnect structure 204 is arranged to
form the second seal ring patterns SP2. That is, the second seal
ring patterns SP2 are formed during the formation of the second
interconnect structure 204. As shown in FIG. 1, the second seal
ring patterns SP2 are at substantially the same level with the
second interconnect structure 204. Specifically, the top surfaces
of the second seal ring patterns SP2 are substantially coplanar
with the top surfaces of the second top metal features 208a of the
second interconnect structure 204.
[0034] The second alignment mark AM2 is disposed over the first
side (e.g., front side) of the second semiconductor substrate 202.
Specifically, the second alignment mark AM2 is disposed over and
electrically insulated from the second device layer, and located
between the second seal ring patterns SP2 within the second seal
ring region 22. In some embodiments, the second alignment mark AM2
is at a floating potential. In some embodiments, the second
interconnect structure 204 is arranged to form the second alignment
mark AM2. In some embodiments, the second alignment mark AM2
includes metal, such as copper. Specifically, the second alignment
mark AM2 is formed during the formation of the second top metal
features 208a of the second interconnect structure 204. In some
embodiments, the second alignment mark AM2 is at substantially the
same level with the second top metal features 208a of the second
interconnect structure 204. Specifically, as shown in FIG. 1, the
top surface of the second alignment mark AM2 is substantially
coplanar with the top surfaces of the second top metal features
208a of the second interconnect structure 204.
[0035] In some embodiments, the second alignment mark AM2 is
square, rectangular, polygonal, round, elliptical, strip-shaped,
T-shaped, L-shaped, box-shaped, cross-shaped or any suitable shape.
For example, the second alignment mark AM2 is designed as four
square islands or square patterns, as shown in FIG. 2 and FIG.
3.
[0036] In some embodiments, the second alignment marks AM2 is
referred to a second overlay mark through the specification. In
some embodiments, multiple second alignment marks AM2 are disposed
in the second seal ring region 22. In some embodiments, two second
alignment marks AM2 are disposed in the diagonal corners of the
second seal ring region 22, as shown in FIG. 2. In alternative
embodiments, four second alignment marks AM2 are disposed in the
four corners of the second seal ring region 22, as shown in FIG.
4.
[0037] One difference between the second die 200 and the first die
100 lies in the die size. In some embodiments, the size of the
second die 200 is different from (e.g., less than) the size of the
first die 100. Herein, the term "size" is referred to the length,
width and/or area. For example, as shown in the top views of FIG. 2
and FIG. 4, the size or area of the second die 200 is less than the
size or area of the first die 100.
[0038] Another difference between the second die 200 and the first
die 100 lies in the positions of alignment marks. Specifically, the
second alignment mark AM2 of the second die 200 is within the
second seal ring region 22, while the first alignment mark AM1 of
the first die 100 is within the first integrated circuit region
10.
[0039] With continuing reference to FIG. 1, the second die 200 is
turned upside down and mounted onto the first die 100. In some
embodiments, the second die 200 and the first die 100 are
face-to-face bonded together with the first bonding structure BS1
and the second bonding structure BS2. In some embodiments, before
the second die 200 is bonded to the first die 100, the second
bonding structure BS2 and the first bonding structure BS1 are
aligned, such that the second bonding pads BP2 are bonded to the
first bonding pads BP1 and the second bonding dielectric layer BDL2
is bonded to the second bonding dielectric layer BDL2. In some
embodiments, the alignment of the first bonding structure BS1 and
the second bonding structure BS2 may be achieved by using an
optical sensing method. After the alignment is achieved, the first
bonding structure BS1 and the second bonding structure BS2 are
bonded together by a hybrid bonding including a metal-to-metal
bonding and a dielectric-to-dielectric bonding.
[0040] After the second die 200 is bonded to the first die 100, the
second alignment mark AM2 corresponds to the first alignment mark
AM1 for inspecting the overlay accuracy between the first alignment
mark AM1 (or called first overlay mark) of the first die 100 and
the second alignment mark AM2 (or called second overlay mark) of
the second die 200. In some embodiments, overlay measurement
optically measure the relative positions of the overlay marks of
different dies. In some embodiments, the measurements of alignment
marks are measured by an optical tool, such as an optical
microscope.
[0041] It is noted that, from the top view of FIG. 2 and FIG. 3,
the first alignment mark AM1 and the second alignment mark AM2 are
both within a corner of the second seal ring region 22 of the
second die 200. Specifically, the second die 200 includes a second
integrated circuit region 20, a second seal ring region 22 around
the second integrated circuit region 20, and an alignment mark
region 21 within the second seal ring region 22. More specifically,
the first alignment mark AM1 and the second alignment mark AM2 are
both within alignment mark region 21 of the second die 200 in a top
view. In some embodiments, from the top view, the first alignment
mark AM1 of the first die 100 surrounds the second alignment mark
AM2 of the second die 200, and the second seal ring patterns SP2
surround the first alignment mark AM1. The second seal ring
patterns SP2 are separated from the first alignment mark AM1 by a
distance.
[0042] In some embodiments, the first alignment mark AM1 is
designed as a square box, and the second alignment mark AM2 is
designed as four square islands within the square box, as shown in
FIG. 2 to FIG. 5. In some embodiments, as shown in FIG. 5, the
dimension W of one square island of second alignment mark AM2 is
about 2.5 .mu.m or more, the first distance (e.g., vertical
distance) D1 between one square island of second alignment mark AM2
and the square box of the first alignment mark AM1 is about 2.5
.mu.m or more, and the second distance (e.g., horizontal distance)
D2 between one square island of second alignment mark AM2 and the
square box of the first alignment mark AM1 is about 2.5 .mu.m or
more.
[0043] In some embodiments, a dielectric encapsulation DE, a
plurality of through dielectric vias TDV, a redistribution layer
structure 302, a plurality of pads 308 and a passivation layer 310
are further included in the three-dimensional integrated circuit
structure of FIG. 1.
[0044] The dielectric encapsulation DE is disposed over the first
die 100 and aside the second die 200. Specifically, the dielectric
encapsulation DE surrounds the sidewall of the second die 200,
exposes the top of the second die 200 and overlays the first side
(e.g., front side) of the first die 100. In some embodiments, the
second side (e.g., back side) of the second die 200 is
substantially planar with the top surface of the dielectric
encapsulation DE. In some embodiments, the dielectric encapsulation
DE includes a molding compound. The molding compound may include a
resin and a filler. In alternative embodiments, the dielectric
encapsulation DE includes silicon oxide, silicon nitride or a
combination thereof. The dielectric encapsulation DE may be formed
by spin-coating, lamination, deposition or the like. In some
embodiments, multiple through-substrate vias (TSV) are formed
through the second semiconductor substrate 202 and are electrically
connected to the second interconnect structure 204.
[0045] The through dielectric vias TDV are disposed in the
dielectric encapsulation DE and electrically connected with the
first interconnect structure 104 and the to-be-formed
redistribution layer structure 302. In some embodiments, the
through dielectric vias TDV include conductive vias. The conductive
vias include copper, a copper alloy, aluminum, an aluminum alloy or
a combination thereof. In some embodiments, the through dielectric
vias TDV further include a diffusion barrier layer between the
conductive vias and the dielectric encapsulation DE. The diffusion
barrier layer includes Ta, TaN, Ti, TiN, CoW or a combination
thereof.
[0046] The redistribution layer structure 302 is disposed over the
second side (e.g., back side) of the second die 200 and over the
dielectric encapsulation DE. The redistribution layer structure 302
includes at least one dielectric layer 304 and at least one
conductive layer 306 stacked alternately. In some embodiments, a
portion of the redistribution layer structure 302 is electrically
connected to the through dielectric vias TDV. In some embodiments,
another portion of the redistribution layer structure 302 is
electrically connected to the through silicon vias. In some
embodiments, the dielectric layer 304 includes a photo-sensitive
material such as polybenzoxazole (PBO), polyimide (PI),
benzocyclobutene (BCB), a combination thereof or the like. In some
embodiments, the conductive layer 306 includes copper, nickel,
titanium, a combination thereof or the like.
[0047] The pads 308 are disposed over the redistribution layer
structure 302. In some embodiments, the pads 308 are under bump
metallization (UBM) pads for mounting conductive connectors, such
as metal pillars, .mu.-bumps or the like. The pads 308 include a
metal or a metal alloy. The pads 308 includes aluminum, copper,
nickel, or an alloy thereof.
[0048] The passivation layer 310 covers the dielectric layer 304
and edge portions of the pads 308, and exposes the center portions
of the pads 308. In some embodiments, the passivation layer 110
includes silicon oxide, silicon nitride, benzocyclobutene (BCB)
polymer, polyimide (PI), polybenzoxazole (PBO) or a combination
thereof.
[0049] The above embodiments in which the first alignment mark AM1
is designed to have a box-shaped pattern and the second alignment
mark AM2 is designed to have four square patterns are provided for
illustration purposes, and are not construed as limiting the
present disclosure. The pattern number, pattern size and shape of
each of the first alignment mark AM1 and the second alignment mark
AM2 can be designed as needed. In some embodiments, from a top
view, the first alignment mark AM1 includes a shape complementary
of a shape of the second alignment mark AM2.
[0050] In some embodiments, as shown in FIG. 6, the first alignment
mark AM1 is designed to have a box-shaped pattern, the second
alignment mark AM2 is designed to have three square patterns, and
the square patterns of the second alignment mark AM2 are within the
box-shaped pattern of the first alignment mark AM1.
[0051] In some embodiments, as shown in FIG. 7, the first alignment
mark AM1 is designed to have four round patterns, the second
alignment mark AM2 is designed to have a cross-shaped pattern, and
the round patterns of the first alignment mark AM1 are around the
cross-shaped pattern of the second alignment mark AM2 when the
first and second alignment marks are aligned.
[0052] In some embodiments, as shown in FIG. 8, the first alignment
mark AM1 is designed to have four square patterns, the second
alignment mark AM2 is designed to have a cross-shaped pattern, and
the square patterns of the first alignment mark AM1 are around the
cross-shaped pattern of the second alignment mark AM2 when the
first and second alignment marks are aligned.
[0053] In some embodiments, as shown in FIG. 9, the first alignment
mark AM1 is designed to have a box-shaped pattern, the second
alignment mark AM2 is designed to have a cross-shaped pattern, and
the cross-shaped pattern of the second alignment mark AM is within
the box-shaped pattern of the first alignment mark AM1 when the
first and second alignment marks are aligned.
[0054] In some embodiments, as shown in FIG. 10, the first
alignment mark AM1 is designed to have a box-shaped pattern, the
second alignment mark AM2 is designed to have another box-shaped
pattern, and the box-shaped pattern of the second alignment mark
AM2 is inside of the box-shaped pattern of the first alignment mark
AM1 when the first and second alignment marks are aligned.
[0055] The above embodiments in which the first alignment mark AM1
is designed for a lower element, device or die and the second
alignment mark AM2 is designed for an upper element, device or die
are provided for illustration purposes, and are not construed as
limiting the present disclosure.
[0056] The first and second alignment marks AM1 and AM2 of FIGS.
5-10 can be exchanged. Specifically, in some embodiments, the first
alignment mark AM1 can be designed for an upper element, device or
die, and the second alignment mark AM2 can be designed for a lower
element, device or die, as shown in FIGS. 11-16.
[0057] In some embodiments, as shown in FIG. 1, the 3DIC structure
1 includes a first die 100 and a second die 200 bonded to the first
die 100. The first die 100 includes a first integrated circuit
region 10 and a first seal ring region 12 around the first
integrated circuit region 10, and has a first alignment mark AM1
within the first integrated circuit region 10. The second die 200
includes a second integrated circuit region 20 and a second seal
ring region 22 around the second integrated circuit region 20, and
has a second alignment mark AM2 within the second seal ring region
22 and corresponding to the first alignment mark AM1.
[0058] In some embodiments, the first alignment mark AM1 is within
the second seal ring region 22 from a top view. In some
embodiments, the first die 100 further has a plurality of first
seal ring patterns SP1 within the first seal ring region 12 and
outside of the second seal ring region 22 from a top view. In some
embodiments, the second die 200 further has a plurality of second
seal ring patterns SP2 within the second seal ring region 22 and
surrounding the second alignment mark AM2. In some embodiments, the
second seal ring patterns SP2 of the second die 200 fall within the
first die 100 from a top view. In some embodiments, the first die
100 further has a first interconnect structure 104, and a first top
metal feature 108a/108b of the first interconnect structure 104 is
at a level substantially the same as that of the first alignment
mark AM1. In some embodiments, the second die 200 further has a
second interconnect structure 204, and a second top metal feature
208a of the second interconnect structure 204 is at a level
substantially the same as that of the second alignment mark AM2. In
some embodiments, each of the first alignment mark AM1 and the
second alignment mark AM2 is square, rectangular, polygonal, round,
elliptical, strip-shaped, T-shaped, L-shaped, box-shaped or
cross-shaped. In some embodiments, the second die 200 is bonded to
the first die 100 through a hybrid bonding including a
metal-to-metal bonding and a dielectric-to-dielectric bonding.
[0059] In some embodiments, as shown in FIG. 1, the 3DIC structure
1 includes a first die 100 and a second die 200. The first die 100
includes a first semiconductor substrate 102, a first interconnect
structure 104 over the first semiconductor substrate 102, a first
alignment mark AM1 over the first semiconductor substrate 102 and
aside the first interconnect structure 104, and a first bonding
structure BS1 over the first interconnect structure 104 and the
first alignment mark AM1. The second die 200 includes a second
semiconductor substrate 202, a second interconnect structure 204
over the second semiconductor substrate 202, a second alignment
mark AM2 over the second semiconductor substrate 202 and aside the
second interconnect structure 204, and a second bonding structure
BS2 over the second interconnect structure 204 and the second
alignment mark AM2. The first die 100 is bonded to the second die
200 with the first bonding structure BS1 and the second bonding
structure BS2. The second die 200 further includes second seal ring
patterns SP2 aside the second interconnect structure 204 and
surrounding the second alignment mark AM2.
[0060] In some embodiments, the first alignment mark AM1 and the
second alignment mark AM2 are within a corner of a second seal ring
region 22 of the second die 200 from a top view. In some
embodiments, the 3DIC structure 1 further includes a plurality of
through dielectric vias TDV over the first die 100 and surrounding
the second die 200. In some embodiments, the 3DIC structure 1
further includes a redistribution layer structure 302 over the
second die 200 and electrically connected to the plurality of
through dielectric vias TDV. In some embodiments, a first bonding
pad BP1 of the first bonding structure BS1 is bonded to a second
bonding pad BP2 of the second bonding structure BS2, and a first
bonding dielectric layer BDL1 of the first bonding structure BS1 is
bonded to a second bonding dielectric layer BDL2 of the second
bonding structure BS2.
[0061] In the above embodiments, two alignment marks (or called
overlay marks) are required for two elements, devices or dies for
inspecting the overlay accuracy between the two elements, devices
or dies. However, the present disclosure is not limited thereto. In
alternative embodiments, only one alignment mark (or called overlay
mark) is required for two elements, devices or dies for inspecting
the overlay accuracy between the two elements, devices or dies.
[0062] FIG. 17 is a cross-sectional view of a 3DIC structure in
accordance with alternative embodiments. FIG. 18 is a simplified
top view of a 3DIC structure in accordance with alternative
embodiments. Specifically, FIG. 17 is a cross-sectional view taken
along the line I-I of FIG. 18. For simplicity and clarity of
illustration, only few elements such as first and second dies and
first and second alignment marks are shown in the simplified top
view of FIG. 18, and these elements are not necessarily in the same
plane. FIG. 19 is an enlarged top view of the part A of FIG.
18.
[0063] The 3DIC structure 2 of FIG. 17 is similar to the 3DIC
structure 1 of FIG. 1. Thus, the difference between the 3DIC
structure 2 and the 3DIC structure 1 is illustrated in details
below and the similarity between them is not iterated herein.
[0064] Referring to FIG. 17, the 3DIC structure 2 includes a first
die 100 and a second die 200 bonded to the first die 200. In some
embodiments, the second die 200 is bonded to the first die 100
through a hybrid bonding including a metal-to-metal bonding and a
dielectric-to-dielectric bonding. The first die 100 includes a
first integrated circuit region 10 and a first seal ring region 12
surrounding the first integrated circuit region 10. The second die
200 includes a second integrated circuit region 20 and a second
seal ring region 22 surrounding the second integrated circuit
region 20.
[0065] In some embodiments, the first die 100 has a first alignment
pattern AM1 within the first integrated circuit region 10. The
first alignment mark AM1 is around a corner of the second seal ring
region 22 from a top view, as shown in FIG. 18 and FIG. 19. In some
embodiments, the first die 100 further has first seal ring patterns
SP1 within the first seal ring region 12 around the first alignment
mark AM1. In some embodiments, from the top view, part of the first
alignment mark AM1 is placed between the first seal ring patterns
SP1 and the second seal ring patterns SP2, as shown in FIG. 17.
[0066] One difference between the 3DIC structure 2 and the 3DIC
structure 1 lies in that, from the top view, the first alignment
pattern AM1 of the first die 100 in FIG. 17 is outside of the
second seal ring region 22, while the first alignment pattern AM1
of the first die 100 in FIG. 1 is within the second seal ring
region 22.
[0067] In some embodiments, no alignment mark is present within the
corner of the second seal ring region 22, as shown in FIG. 18 and
FIG. 19. Specifically, only second seal sing patterns SP2 are
configured in the corner of the second seal ring region 22 of the
second die 200.
[0068] Another difference between the 3DIC structure 2 and the 3DIC
structure 1 lies in that, the second alignment mark AM2 of the
second die 200 is configured for the 3DIC structure 1 in FIG. 1,
while no such element is configured for the 3DIC structure 2 in
FIG. 17. Instead, the seal ring border of the second seal ring
region 22 functions as the second alignment mark for the second die
200 of the 3DIC structure 2 in FIG. 17.
[0069] In some embodiments, the first alignment mark AM1 is square,
rectangular, polygonal, strip-shaped, T-shaped, L-shaped,
box-shaped, cross-shaped or any suitable shape. For example, the
first alignment mark AM1 is designed as a square box, as shown in
FIG. 17 and FIG. 18.
[0070] In some embodiments, multiple first alignment marks AM1 are
disposed in the first integrated circuit region 10. In some
embodiments, two first alignment marks AM1 are disposed around the
diagonal corners of the second seal ring region 22, as shown in
FIG. 18. In alternative embodiments, four first alignment marks AM1
are disposed around the four corners of the second seal ring region
22, as shown in FIG. 20.
[0071] In some embodiments, the first alignment mark AM1 includes a
first alignment pattern AP1 parallel to a first border SB1 of the
second seal ring region 22, and a second alignment pattern AP2
parallel to a second border SB2 of the second seal ring region 22,
as shown in FIG. 19. In some embodiments, the first distance (e.g.,
vertical distance) D1 between the first alignment pattern AP1 of
the first alignment mark AM1 and the first border SB1 of the second
seal ring region 22 is from about 2 .mu.m to about 10 .mu.m, and
the second distance (e.g., horizontal distance) D2 between the
second alignment pattern AP2 of the first alignment mark AM1 and
the second border SB2 of the second seal ring region 22 is from
about 2 .mu.m to about 10 .mu.m.
[0072] In some embodiments, the first alignment pattern AP1 and the
second alignment pattern AP2 of the first alignment mark AM1 are
connected to each other. In alternative embodiments, the first
alignment pattern AP1 and the second alignment pattern AP2 of the
first alignment mark AM1 can be separated from one another.
[0073] In some embodiments, the first alignment mark AM1 is
designed as a square box, and the first alignment mark AM1 of the
first die 100 is partially overlapped with the second seal ring
patterns SP2 of the second die 200 from a top view, as shown in
FIGS. 17-20.
[0074] In alternative embodiments, the first alignment mark AM1 is
designed to have an L-shape, and the first alignment mark AM1 of
the first die 100 is not overlapped with the second seal ring
patterns SP2 of the second die 200 from a top view, as shown in
FIGS. 21-22.
[0075] In the application, the alignment marks of a 3DIC structure
are configured in a space-saving manner. Specifically, in the
conventional die stack structure, two alignment marks are placed in
the integrated circuit regions of two bonded dies, so the available
chip areas are reduced. On the contrary, in the application, in
some embodiments, two alignment marks of two bonded dies are placed
in at least one corner of the seal ring region of one die, without
reducing the available chip areas. In alternative embodiments, only
one alignment mark is place around at least one corner of the seal
ring region of one die of the bonded structure, and thus, not only
the chip area is saved but also the layout design is
simplified.
[0076] In view of the above, an improved die-to-die alignment
technique as herein provided takes advantage of forming alignment
marks (or overlay marks) within or around a seal ring region of one
die. By providing alignment marks (or overlay marks) within or
around a seal ring region of one die, the die-to-die alignment can
be improved without reducing the available chip areas. Many
variations of the above examples are contemplated by the present
disclosure. It is understood that different embodiments may have
different advantages, and that no particular advantage is
necessarily required of all embodiments.
[0077] In accordance with some embodiments of the present
disclosure, a 3DIC structure includes a first die and a second die
bonded to the first die. The first die includes a first integrated
circuit region and a first seal ring region around the first
integrated circuit region, and has a first alignment mark within
the first integrated circuit region. The second die includes a
second integrated circuit region and a second seal ring region
around the second integrated circuit region, and has a second
alignment mark within the second seal ring region and corresponding
to the first alignment mark.
[0078] In accordance with alternative embodiments of the present
disclosure, a 3DIC structure includes a first die and a second die
bonded to the first die. The first die includes a first integrated
circuit region and a first seal ring region surrounding the first
integrated circuit region, and has a first alignment pattern within
the first integrated circuit region. The second die includes a
second integrated circuit region and a second seal ring region
surrounding the second integrated circuit region. The first
alignment mark is around a corner of the second seal ring region
from a top view.
[0079] In accordance with yet alternative embodiments of the
present disclosure, a 3DIC structure includes a first die and a
second die. The first die includes a first semiconductor substrate,
a first interconnect structure over the first semiconductor
substrate, a first alignment mark over the first semiconductor
substrate and aside the first interconnect structure, and a first
bonding structure over the first interconnect structure and the
first alignment mark. The second die includes a second
semiconductor substrate, a second interconnect structure over the
second semiconductor substrate, a second alignment mark over the
second semiconductor substrate and aside the second interconnect
structure, and a second bonding structure over the second
interconnect structure and the second alignment mark. The first die
is bonded to the second die with the first bonding structure and
the second bonding structure. The second die further includes seal
ring patterns aside the second interconnect structure and
surrounding the second alignment mark.
[0080] Other features and processes may also be included. For
example, testing structures may be included to aid in the
verification testing of the 3D packaging or 3DIC devices. The
testing structures may include, for example, test pads formed in a
redistribution layer or on a substrate that allows the testing of
the 3D packaging or 3DIC, the use of probes and/or probe cards, and
the like. The verification testing may be performed on intermediate
structures as well as the final structure. Additionally, the
structures and methods disclosed herein may be used in conjunction
with testing methodologies that incorporate intermediate
verification of known good dies to increase the yield and decrease
costs.
[0081] The foregoing outlines features of several embodiments so
that those skilled in the art may better understand the aspects of
the present disclosure. Those skilled in the art should appreciate
that they may readily use the present disclosure as a basis for
designing or modifying other processes and structures for carrying
out the same purposes and/or achieving the same advantages of the
embodiments introduced herein. Those skilled in the art should also
realize that such equivalent constructions do not depart from the
spirit and scope of the present disclosure, and that they may make
various changes, substitutions, and alterations herein without
departing from the spirit and scope of the present disclosure.
* * * * *