U.S. patent application number 15/007762 was filed with the patent office on 2017-07-27 for mems device and multi-layered structure.
The applicant listed for this patent is TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.. Invention is credited to CHUN-WEN CHENG, JIOU-KANG LEE.
Application Number | 20170210614 15/007762 |
Document ID | / |
Family ID | 59358883 |
Filed Date | 2017-07-27 |
United States Patent
Application |
20170210614 |
Kind Code |
A1 |
CHENG; CHUN-WEN ; et
al. |
July 27, 2017 |
MEMS DEVICE AND MULTI-LAYERED STRUCTURE
Abstract
A device includes a substrate, a first structure, a second
structure, a third structure and a bumper. The first structure is
over the substrate. The second structure is over the substrate,
wherein the second structure has a first end coupled to the first
structure. The third structure is over the substrate, wherein the
third structure is coupled to a second end of the second structure.
The bumper is between the substrate and the third structure,
wherein the bumper is a multi-layered bumper including a first
conductive feature, a dielectric feature and a second conductive
feature. The dielectric feature is over the first conductive
feature. The second conductive feature is over the dielectric
feature and electrically connected to the first conductive
feature.
Inventors: |
CHENG; CHUN-WEN; (HSINCHU
COUNTY, TW) ; LEE; JIOU-KANG; (HSINCHU, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. |
HSINCHU |
|
TW |
|
|
Family ID: |
59358883 |
Appl. No.: |
15/007762 |
Filed: |
January 27, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B81B 3/0008 20130101;
B81C 1/00825 20130101; B81B 2201/0235 20130101; B81B 2201/0242
20130101; B81B 3/001 20130101 |
International
Class: |
B81B 3/00 20060101
B81B003/00 |
Claims
1. A device, comprising: a substrate; a first structure over the
substrate; a second structure over the substrate, wherein the
second structure has a first end coupled to the first structure; a
third structure over the substrate, wherein the third structure is
coupled to a second end of the second structure; and a bumper
between the substrate and the third structure, wherein the bumper
is a multi-layered bumper comprising: a first conductive feature; a
dielectric feature over the first conductive feature; and a second
conductive feature over the dielectric feature and electrically
connected to the first conductive feature.
2. The device of claim 1, wherein the first conductive feature has
a recess, the dielectric feature is disposed on the first
conductive feature, a portion of the dielectric feature is in the
recess, and the second conductive feature covers a portion of the
dielectric feature.
3. The device of claim 2, wherein the dielectric feature has a top
surface and a slanted sidewall, and the second conductive feature
covers the slanted sidewall and a portion of the top surface of the
dielectric feature.
4. The device of claim 1, wherein the second structure and the
third structure are conductive.
5. The device of claim 4, further comprising a connection feature
electrically connected to the third structure and the bumper.
6. The device of claim 5, wherein the connection feature comprises:
a first connection structure over the substrate; a first conductive
via electrically connected to the first conductive feature and the
first connection structure; a second connection structure over the
substrate; a second conductive via electrically connected to the
first connection structure and the second connection structure; and
a third conductive via electrically connected to the second
connection structure and the first structure.
7. The device of claim 6, wherein the second connection structure
of the connection feature and the first conductive feature of the
bumper are formed of a same conductive layer.
8. The device of claim 1, wherein a material of the first
conductive feature comprises metal.
9. The device of claim 1, wherein a material of the second
conductive feature comprises metal.
10. The device of claim 1, wherein the first structure is a
stationary structure, the second structure is a resilient
structure, the third structure is a proof mass coupled to the
resilient structure, and the resilient structure is configured to
allow the proof mass to move toward or away from the substrate in a
direction.
11. A MEMS device, comprising: a substrate; a stationary structure
over the substrate, wherein the stationary structure exposes a
portion of the substrate; a proof mass over the substrate; a spring
anchoring the proof mass to the stationary structure; and a bumper
between the substrate and the proof mass, wherein the bumper and
the proof mass are electrically connected to each other.
12. The MEMS device of claim 11, wherein the bumper is a
multi-layered bumper comprising: a dielectric feature over the
substrate; and a top conductive film covering the dielectric
feature.
13. The MEMS device of claim 12, wherein the dielectric feature has
a top surface and a sidewall with a taper profile, and the top
conductive film covers the sidewall and at least a portion of the
top surface of the dielectric feature.
14. The MEMS device of claim 13, wherein the bumper further
comprises a bottom conductive feature between the dielectric
feature and the substrate.
15. The MEMS device of claim 14, wherein the bottom conductive
feature is electrically coupled to the proof mass.
16. The MEMS device of claim 11, further comprising a plate over
the substrate, wherein the proof mass and the plate form a
capacitor.
17. The MEMS device of claim 11, wherein the bumper is disposed
corresponding to an end of the proof mass distal to the spring.
18-20. (canceled)
18. A device comprising: a substrate; a first structure over the
substrate; a second structure over the substrate, wherein the
second structure has a first end coupled to the first structure; a
third structure over the substrate, wherein the third structure is
coupled to a second end of the second structure; and a bumper
between the substrate and the third structure, wherein the bumper
is a multi-layered bumper comprising: a bottom conductive feature
over the substrate, wherein the bottom conductive feature has a
recess exposing the substrate; a dielectric feature on the bottom
conductive feature, wherein a portion of the dielectric feature is
in the recess; and a top conductive film at least covering a
portion of the dielectric feature, and electrically connected to
the bottom conductive feature.
19. The device of claim 18, wherein the dielectric feature has a
top surface and a slanted sidewall, and the top conductive film
covers the slanted sidewall and a portion of the top surface of the
dielectric feature.
20. The device of Claim 18, wherein the second structure and the
third structure are conductive.
Description
BACKGROUND
[0001] Microelectromechanical Systems (MEMS) device is micro-sized
device, normally in a range from less than 1 micron to several
millimeters in size. The MEMS device includes mechanical elements
(stationary element and/or movable element) to sense a physical
condition such as force, acceleration, pressure, temperature or
vibration, and electronic elements to process electrical signals.
The MEMs devices are widely used in applications such as automotive
system, inertial guidance systems, household appliances, protection
systems for a variety of devices, and many other industrial,
scientific, and engineering systems. Moreover, MEMS applications
are extended to optical applications, such as movable mirrors, and
radio frequency (RF) applications, such as RF switches.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] Aspects of the present disclosure are best understood from
the following detailed description when read with the accompanying
figures. It is noted that, in accordance with the standard practice
in the industry, various features are not drawn to scale. In fact,
the dimensions of the various features may be arbitrarily increased
or reduced for clarity of discussion.
[0003] FIG. 1 is a schematic top view of some embodiments of a
device.
[0004] FIG. 1A is a schematic cross-sectional view taken along line
A-A' of FIG. 1.
[0005] FIG. 1B is an enlarged cross-sectional view of some
embodiments of a device corresponding to FIG. 1A.
[0006] FIG. 2 is a schematic diagram of some embodiments of a
device undergone a first force within the maximum force
tolerance.
[0007] FIG. 3 is a schematic diagram of some embodiments of a
device undergone a second force beyond the maximum force
tolerance.
[0008] FIG. 4 is a schematic cross-sectional view of some
embodiments of a device.
[0009] FIG. 5 is a schematic cross-sectional view of some
embodiments of a device.
DETAILED DESCRIPTION
[0010] The following disclosure provides many different
embodiments, or examples, for implementing different features of
the provided subject matter. Specific examples of elements and
arrangements are described below to simplify the present
disclosure. These are, of course, merely examples and are not
intended to be limiting. For example, the formation of a first
feature over or on a second feature in the description that follows
may include embodiments in which the first and second features are
formed in direct contact, and may also include embodiments in which
additional features may be formed between the first and second
features, such that the first and second features may not be in
direct contact. In addition, the present disclosure may repeat
reference numerals and/or letters in the various examples. This
repetition is for the purpose of simplicity and clarity and does
not in itself dictate a relationship between the various
embodiments and/or configurations discussed.
[0011] Further, spatially relative terms, such as "beneath,"
"below," "lower," "above," "upper", "on" and the like, may be used
herein for ease of description to describe 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.
[0012] In the present disclosure, a device including a suspended
movable structure, a resilient structure and a bumper is provided.
The movable structure is suspended from e.g., a substrate with a
space such as an air space. The resilient structure is a
flexible/elastic structure, which allows extending, compressing,
deforming or swinging to a certain degree. One of the ends of the
resilient structure is fixed to an object e.g., a substrate or a
stationary structure, while another one of the ends is structurally
connected to the suspended movable structure in such a manner that
the suspended movable structure is able to move, swing or rotate
when the device experiences a force, an acceleration, a
deceleration, a vibration, an impact or the like. The bumper is
disposed adjacent to the movable structure to prevent the movable
structure from being broken and/or adhered to the substrate or any
structures overlying the substrate.
[0013] In the present disclosure, a MEMS device including a spring,
a proof mass and a bumper is provided. A portion of the proof mass
and the bumper are spaced away, and the proof mass and the bumper
are electrically connected to each other. When the proof mass
contacts the bumper, electrical charges are equalized.
[0014] In the present disclosure, the device includes, but is not
limited to, a MEMS device, such as a motion sensor device, an
accelerometer device, or a gyroscope device. The suspended movable
structure may include a proof mass, a diaphragm, or any other
movable structures. The resilient structure may include a spring,
or any other resilient structures with resilience.
[0015] As used herein, a "substrate" refers to a base material on
which various layers and structures are formed. In some
embodiments, the substrate includes a semiconductor substrate, such
as a bulk semiconductor substrate. By way of example, the bulk
semiconductor substrate includes an elementary semiconductor, such
as silicon or germanium; a compound semiconductor, such as silicon
germanium, silicon carbide, gallium arsenic, gallium phosphide,
indium phosphide, or indium arsenide; or combinations thereof. In
some embodiments, the substrate includes a multilayered substrate,
such as a silicon-on-insulator (SOI) substrate, which includes a
bottom semiconductor layer, a buried oxide layer (BOX) and a top
semiconductor layer. In still some embodiments, the substrate
includes an insulative substrate, such as a glass substrate, a
conductive substrate, or any other suitable substrate. In some
embodiments, the substrate is a doped semiconductor substrate.
[0016] As used herein, "couple to" refers to a structure directly
or indirectly contacting another structure.
[0017] As used herein, "suspended" refers to a structure disposed
above and spaced away from another structure, thereby allowing the
structure is able to move in at least one direction with respective
to another structure.
[0018] As used herein, a "movable structure" refers to a structure
that is formed over the substrate or part of the substrate, where
some part of the movable structure is directly or indirectly
coupled to the a resilient structure, and some part of the movable
structure is suspended over the substrate or some part of the
substrate with a space therebetween. Accordingly, the movable
structure is able to move or swing when experiencing a force, an
acceleration, a deceleration, a vibration, an impact or the like.
In some embodiments, the movable structure is conductive. For
example, the movable structure includes a semiconductor material
e.g., silicon doped with p type or n type dopants. In some
embodiments, the movable structure includes a dielectric material
and a conductive material enclosing the dielectric material. For
example, the dielectric material is silicon or silicon compound
,e.g., silicon oxide, and the conductive material is metal. In some
embodiments, the movable structure is not conductive.
[0019] As used herein, a "resilient structure" refers to a
structure that is formed over the substrate or a part of the
substrate, where some part of the resilient structure is fixed on
the substrate or other fixed structure, and some part of the
resilient structure is coupled to the movable structure. The
resilient structure is a flexible/elastic structure, which allows
extending, compressing, or deforming to a certain degree. In some
embodiments, the resilient structure has a winding pattern that
allows the resilient structure to extend or compress. In some
embodiments, the movable structure has a mass greater than that of
the resilient structure, and thus the movable structure is able to
move or swing due to inertial effect when experiencing a force, an
acceleration, a deceleration, a vibration, an impact or the like.
In some embodiments, the resilient structure is conductive. For
example, the resilient structure includes a semiconductor material
e.g., silicon doped with p type or n type dopants. In some
embodiments, the resilient structure includes a dielectric material
and a conductive material enclosing the dielectric material. For
example, the dielectric material is silicon or silicon compound
e.g., silicon oxide, and the conductive material is metal. In some
embodiments, the resilient structure is not conductive.
[0020] As used herein, a "stationary structure" or a "fixed
structure" refers to a structure that is immobile with respect to
the movable structure and the resilient structure when experiencing
a force, an acceleration, a deceleration, a vibration, an impact or
the like. The stationary structure or the fixed structure may be
formed directly or indirectly on the substrate, or is a part of the
substrate. In some embodiments, the stationary structure is
conductive. For example, the stationary structure includes a
semiconductor material e.g., silicon doped with p type or n type
dopants. In some embodiments, the stationary structure includes a
dielectric material and a conductive material enclosing the
dielectric material. For example, the dielectric material is
silicon, or silicon compound e.g., silicon oxide, and the
conductive material is metal. In some embodiments, the stationary
structure is not conductive.
[0021] As used herein, "monolithically formed" refers to two or
more structures are formed of the same material(s) and
simultaneously. By way of example, two or more structures are
formed by the same lithography.
[0022] As used herein, a "bumper" is a structure configured as a
buffer to reduce damage in a collision and to avoid undesired
adhesion. The bumper is disposed adjacent to the movable structure
and in a path where the movable structure may reach.
[0023] FIG. 1 is a schematic top view of some embodiments of a
device. FIG. 1A is a schematic cross-sectional view taken along
line A-A' of FIG. 1. FIG. 1B is an enlarged cross-sectional view of
some embodiments of a device corresponding to FIG. 1A. In some
embodiments, the device 100 is a MEMS device. By way of example,
the MEMS device includes a motion sensor device able to sense
motion, an accelerometer device able to sense acceleration or
deceleration, a gyroscope device able to sense angular velocity, or
any other devices with movable structure. In some embodiments, the
device is a single-axis MEMS device able to sense motion,
acceleration or angular velocity in one single direction (e.g., Z
direction). In some other embodiments, the device is a double-axis
MEMS device able to sense motion, acceleration or angular velocity
in two directions (e.g., X, Z directions). In still other
embodiments, the device is a triple-axis MEMS device able to sense
motion, acceleration or angular velocity in three directions (e.g.,
X, Y, Z directions).
[0024] The device 100 includes a substrate 10, a first structure
12, a second structure 14, a third structure 16, and a bumper 20.
The first structure 12 is disposed over the substrate 10. In some
embodiments, the first structure 12 is a stationary structure fixed
on the substrate 10. In some embodiments, the first structure 12 is
a semiconductor layer, a stack of semiconductor layer, a dielectric
layer, a stack of dielectric layers, or combinations thereof. By
way of example, the material of the first structure 12 includes
silicon such as polycrystalline silicon. In some other embodiments,
the material of the first structure 12 includes silicon oxide,
silicon nitride, silicon oxynitride, or the any other suitable
materials. The first structure 12 exposes a portion of the
substrate 10, or exposes overlying layer(s) of a portion of the
substrate 10.
[0025] The second structure 14 is disposed over the substrate 10.
Specifically, the second structure 14 is suspended over the
substrate 10, and spaced away from the substrate 10 with a space
e.g., an air space. In some embodiments, the second structure 14 is
a resilient structure. The resilient structure is a flexible
structure or an elastic structure, which allows extending,
compressing or deforming to a certain degree. By way of example,
the second structure 14 is a spring. The second structure 14 has a
first end (fixed end) 141 which is directly or indirectly coupled
to the first structure 12. The second structure 14 has a second end
(movable end) which is directly or indirectly coupled to the third
structure 16. Specifically, the second structure 14 anchors the
third structure 16 to the first structure 12. In some embodiments,
a plurality of second structure 14 are coupled to different sides
of the first structure 12, or coupled to different first structures
12. In some embodiments, the first structure 12 and the second
structure 14 are formed of the same material e.g. polycrystalline
silicon or the like, and formed monolithically.
[0026] The third structure 16 is over the substrate 10. The third
structure 16 is suspended over the substrate 10, and spaced away
from the substrate 10 with a gap e.g., an air gap. In some
embodiments, the third structure 16 is an inertial structure which
has a mass relatively greater than that of the second structure 14.
The third structure 16 is a movable structure. By way of example,
the third structure 16 is a proof mass. In some embodiments, one
end of the third structure 16 is coupled to the second end (movable
end) 142 of the second structure 14. In some embodiments, two or
more ends of the third structure 16 are coupled to the movable ends
of respective second structures 14. The third structure 16 is
supported by the second structure 14. The second structure 14 is
configured to allow the third structure 16 to move or swing at
least in a Z direction (e.g., a direction substantially
perpendicular to the upper surface of the substrate 10) due to
inertial effect when the device 100 experiences a force, an
acceleration, a deceleration, a vibration, an impact or the like.
In some embodiments, the first structure 12, the second structure
14 and the third structure 16 are formed of the same material e.g.,
polycrystalline silicon or the like, and formed monolithically. In
some embodiments, the first structure 12, the second structure 14
and the third structure 16 are formed by patterning overlying
layer(s) over the substrate 10. In some embodiments, the first
structure 12, the second structure 14 and the third structure 16
are formed by patterning the substrate 10, i.e., the first
structure 12, the second structure 14 and the third structure 16
are a part of the substrate 10.
[0027] In some embodiments, the device 100 further includes a plate
30 of a capacitor over the substrate 10. The plate 30 is conductive
plate such as a metal plate. In some embodiments, the plate 30
overlaps a portion of the third structure 16 in the direction Z,
thereby forming a capacitor. In some embodiments, the plate 30
overlaps a portion of the second structure 14 in the direction Z.
Accordingly, motion, acceleration or angular velocity of the third
structure 16 can be sensed e.g., due to a capacitance variation
between the plate 30 and the third structure 16.
[0028] In some embodiments, the bumper 20 is disposed between the
substrate 10 and the third structure 16. The bumper 20 is
configured to prevent the third structure 16 from being broken when
hitting the substrate 10 or any structures overlying the substrate
10 and adhered to the substrate or any structures overlying the
substrate 10. Thus, the bumper 20 is also referred to as a stopper.
The bumper 20 is disposed adjacent to the third structure 16, and
is in the path where the third structure 16 may reach. In some
embodiments, the bumper 20 is disposed on the substrate 10. In some
other embodiments, the bumper 20 is disposed over the substrate 10
with intermediate layer(s) disposed therebetween. The bumper 20 is
a multi-layered bumper. In some embodiments, the bumper 20 includes
a first conductive feature (also referred to as a bottom conductive
feature) 21, a dielectric feature 22 and a second conductive
feature (also referred to as a top conductive film) 23 stacked to
one another. In some embodiments, the first conductive feature 21
is formed on the substrate 10. The dielectric feature 22 is formed
over the first conductive feature 21. The second conductive feature
23 is formed over the dielectric feature 22 and electrically
connected to the first conductive feature 21. The first conductive
feature 21 and the second conductive feature 23 are formed of
conductive material such as metal. The first conductive feature 21
and the second conductive feature 23 may be formed of the same
material or different materials. The dielectric feature 22 is
formed of insulative material such as silicon oxide, silicon
nitride, silicon oxynitride, or any other suitable inorganic or
organic materials. In some embodiments, the material of the second
conductive feature 23 is softer or flexible than that of the
dielectric feature 22. In some embodiments, the first conductive
feature 21 and/or the second conductive feature 23 can be formed
monolithically with the plate 30.
[0029] In some embodiments, the first conductive feature 21 has a
recess 21H. The dielectric feature 22 is disposed on the first
conductive feature 21, and a portion of the dielectric feature 22
is in the recess. In other words, the dielectric feature 22 is
engaged with the first conductive feature 21, thereby preventing
the dielectric feature 22 from sliding or shifting. The second
conductive feature 23 covers at least a portion of the dielectric
feature 22. In some embodiments, the dielectric feature 22 has a
top surface 221 and a slanted sidewall 222, and the second
conductive feature 22 covers the slanted sidewall 222 and a portion
of the top surface 221 of the dielectric feature 22. By way of
example, the dielectric feature 22 has a trapezoid cross-sectional
shape, in which the slanted sidewall 222 is slanted outwardly. The
slope of the slanted sidewall 222 may be modified based on
different consideration. In some embodiments, the second conductive
feature 23 is a conductive film, which surrounds the slanted
sidewall 222 and covers a portion of the top surface 221. In some
embodiments, the second conductive feature 23 is substantially
conformal to the slanted sidewall 222 and/or the top surface 221 of
the dielectric feature 22. With the slanted taper profile, the step
coverage of the second conductive feature 23 can be improved,
thereby increasing adhesion.
[0030] The bumper 20 is configured to prevent the third structure
16 from being adhered to the substrate 10 or an overlying layer on
the substrate 10 when the device 100 experiences a force, an
acceleration, a deceleration, a vibration, an impact or the like in
the direction Z. The multi-layered bumper 20 includes soft material
such as the second conductive feature 23 and/or the first
conductive feature 21, and hard material such as the dielectric
feature 22. The second conductive feature 23 and/or the first
conductive feature 21 provides a buffer effect when the third
structure 16 contacts the bumper 20 so as to avoid generation of
particles. The dielectric feature 22 provides a substantive
supporting effect when the third structure 16 contacts the bumper
20 so as to avoid stiction. The thickness and the position of the
bumper 20 can be modified based on different considerations. For
example, the thickness of the bumper 20 is greater than other
structure on the substrate e.g., the plate 30. The bumper 20 is
disposed at a location where the third structure 16 is expected to
contact the substrate 10 or an overlying layer when the third
structure 16 moves toward the substrate 10, or at a location where
the amplitude of the third structure 16 is maximum when the device
100 experiences a force, an acceleration, a deceleration, a
vibration, an impact or the like in the direction Z. In some
embodiments, the bumper 20 is disposed corresponding to an end of
the third structure 16 distal to the second structure 14. An
exemplary operation mechanism of the bumper 20 is explained in the
following descriptions.
[0031] FIG. 2 is a schematic diagram of some embodiments of a
device undergone a first force within the maximum force tolerance.
As depicted in FIG. 2, when the device 100 experiences a force F1
in direction Z due to a form of shock, both the second structure 14
and the third structure 16 coupled thereto will move or rotate
toward the plate 30 along the direction Z due to inertial effect.
Accordingly, the motion, acceleration or angular velocity of the
third structure 16 can be sensed by detecting a capacitance
variation between the third structure 16 and the plate 30. In case
the first force F1 does not exceed the maximum force tolerance, the
second structure 14 and third structure 16 will move or rotate
toward the first structure 12 without contacting the bumper 20, and
return to their initial positions.
[0032] In some embodiments, the third structure 16 may be attracted
by the bumper 20 due to electrical charge accumulation. The bumper
20 may be electrically coupled to a ground terminal or to the third
structure 16 to equalize the electrical charge accumulated in the
third structure 16 when they are contacted.
[0033] FIG. 3 is a schematic diagram of some embodiments of a
device undergone a second force beyond the maximum force tolerance.
As depicted in FIG. 3, when the device 100 experiences a second
force F2 greater than the maximum force tolerance in direction Z
due to another form of shock, both the second structure 14 and the
third structure 16 coupled thereto will move or rotate toward the
plate 30 along the direction Z due to inertial effect. When the
second force F2 is excessive, the third structure 16 will contact
the multi-layered bumper 20. In such a case, the second conductive
feature 23 and/or the first conductive feature 21 provides a buffer
effect when the third structure 16 contacts the bumper 20 so as to
avoid generation of particles. The dielectric feature 22 provides a
substantive supporting effect when the third structure 16 contacts
the bumper 20 so as to avoid stiction.
[0034] The device of the present disclosure is not limited to the
above-mentioned embodiments, and may have other different
embodiments. To simplify the description and for the convenience of
comparison between each of the embodiments of the present
disclosure, the identical components in each of the following
embodiments are marked with identical numerals. For making it
easier to compare the difference between the embodiments, the
following description will detail the dissimilarities among
different embodiments and the identical features will not be
redundantly described.
[0035] FIG. 4 is a schematic cross-sectional view of some
embodiments of a device. As depicted in FIG. 4, one difference
between the device 110 and the device 100 is that the first
conductive feature 21 of the bumper 20 is omitted. In some
embodiments, the bumper 20 of the device 110 includes the
dielectric feature 22 and the second conductive feature 23. The
second conductive feature 23 covers at least a portion of the
dielectric feature 22. In some embodiments, the second conductive
feature 22 covers the slanted sidewall 222 and a portion of the top
surface 221 of the dielectric feature 22.
[0036] When the third structure 16 contacts the multi-layered
bumper 20, the second conductive feature 23 21 is able to provide a
buffer effect when the third structure 16 contacts the bumper 20,
thereby avoiding generation of particles. In addition, the
dielectric feature 22 is able to provide a substantive supporting
effect, thereby avoiding stiction.
[0037] FIG. 5 is a schematic cross-sectional view of some
embodiments of a device. As depicted in FIG. 5, one difference
between the device 200 and the device 100 is that the device 200
further includes a connection feature 40 electrically connected to
the third structure 16 and the bumper 20. In some embodiments, the
connection feature 40 a first connection structure 41, a first
conductive via 42, a second connection structure 43, a second
conductive via 44 and a third conductive via 45. The first
connection structure 41 is disposed over the substrate 10 and under
the first conductive feature 21. The material of the first
connection structure 41 includes conductive material e.g. metal,
but not limited thereto. In some embodiments, the first connection
structure and the first conductive feature 21 are electrically
connected to each other through the first conductive via 42. The
second connection structure 43 is disposed over the substrate 10.
In some embodiments, second connection structure 43 is covered by
the first structure 12. The material of the second connection
structure 43 includes conductive material e.g. metal. In some
embodiments, the second connection structure 43 is formed
monolithically with first conductive feature 21. The second
conductive via 44 is disposed between and electrically connected to
the first connection structure 41 and the second connection
structure 43. The third conductive via 45 is disposed be
electrically connected to the second connection structure 43 and
the first structure 12. The first, second and third conductive vias
42, 44 and 45 may be made of any suitable conductive material such
as copper.
[0038] By virtue of the connection feature 40, the third structure
16 is able to be electrically connected to the bumper 20. As a
result, when the third structure 16 contacts the bumper 20, the
electrical charge between the third structure 16 and the bumper 20
can be equalized.
[0039] In the present disclosure, the device includes a suspended
movable structure and a bumper is provided. The movable structure
is suspended and able to move, swing or rotate when the device
experiences a force. The bumper is a multi-layered bumper including
a dielectric feature and a conductive feature enclosing the
dielectric feature. The conductive feature provides a buffer effect
when the movable structure contacts the bumper so as to avoid
generation of particles. The dielectric feature provides a
supporting effect when the movable structure contacts the bumper so
as to avoid stiction.
[0040] In the present disclosure, a MEMS device including a spring,
a proof mass and a bumper is provided. A portion of the proof mass
and the bumper are spaced away, and the proof mass and the bumper
are electrically connected to each other. When the proof mass
contacts the bumper, electrical charges are equalized.
[0041] In one exemplary aspect, a device is provided. The device
includes a substrate, a first structure, a second structure, a
third structure and a bumper. The first structure is over the
substrate. The second structure is over the substrate, wherein the
second structure has a first end coupled to the first structure.
The third structure is over the substrate, wherein the third
structure is coupled to a second end of the second structure. The
bumper is between the substrate and the third structure, wherein
the bumper is a multi-layered bumper including a first conductive
feature, a dielectric feature and a second conductive feature. The
dielectric feature is over the first conductive feature. The second
conductive feature is over the dielectric feature and electrically
connected to the first conductive feature.
[0042] In another exemplary aspect, a MEMS device is provided. The
MEMS device includes a substrate, a stationary structure, a proof
mass, a spring and a bumper. The stationary structure is over the
substrate, wherein the stationary structure exposes a portion of
the substrate. The proof mass is over the substrate. The spring
anchors the proof mass to the stationary structure. The bumper is
between the substrate and the proof mass, wherein the bumper and
the proof mass are electrically connected to each other.
[0043] In yet another exemplary aspect, a multi-layered structure
formed over a substrate is provided. The multi-layered structure
includes a bottom conductive feature, a dielectric feature and a
top conductive film. The bottom conductive feature is over the
substrate, and the bottom conductive feature has a recess exposing
the substrate. The dielectric feature is on the bottom conductive
feature, wherein a portion of the dielectric feature is in the
recess. The top conductive film at least covers a portion of the
dielectric feature.
[0044] 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.
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