CN107205203B - MEMS structure and manufacturing method thereof - Google Patents
MEMS structure and manufacturing method thereof Download PDFInfo
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- CN107205203B CN107205203B CN201610158466.3A CN201610158466A CN107205203B CN 107205203 B CN107205203 B CN 107205203B CN 201610158466 A CN201610158466 A CN 201610158466A CN 107205203 B CN107205203 B CN 107205203B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/005—Electrostatic transducers using semiconductor materials
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2231/00—Details of apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor covered by H04R31/00, not provided for in its subgroups
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Abstract
MEMS structures and methods of fabricating the same are disclosed. The MEMS structure includes: a substrate; a movable member located over the substrate; a fixed member that is located on the movable member and is opposed to the movable member to form a capacitance plate; a second pad on the fixing member; an interconnecting member connecting the movable member levels; and a first pad on the interconnect feature, the interconnect feature having a height difference between the first pad and the second pad of less than 10 microns. The MEMS structure utilizes the interconnection part to set a constraint point on the diaphragm, thereby improving the vibration mode of the diaphragm.
Description
Technical Field
The present invention relates to a method of manufacturing a MEMS (micro electro mechanical system) structure, and more particularly, to a method of manufacturing a MEMS structure including a diaphragm.
Background
MEMS devices are electromechanical devices that are developed based on microelectronics and are fabricated using micromachining processes, and have been widely used as sensors and actuators. For example, the MEMS device may be a silicon condenser microphone. A silicon condenser microphone generally includes a substrate, a back plate, and a diaphragm, wherein the diaphragm is a core component of the silicon condenser microphone, and the diaphragm sensitively responds to a sound pressure signal and converts it into an electrical signal. In a silicon condenser microphone, a substrate and a back plate are fixed members, and a diaphragm is a movable member. One end of the vibrating diaphragm is fixed on the substrate, and the other end can freely vibrate. Like silicon condenser microphones, MEMS sensors based on capacitive characteristics and most MEMS actuators comprise a fixed part and a movable part.
In a typical structure, the MEMS structure includes first and second pads that lead from the movable and fixed components, respectively. Since the movable member and the fixed member are located at different levels, the first pad and the second pad are generally provided at different levels corresponding to the movable member and the fixed member. Fig. 1a and 1b show a top view and a cross-sectional view of a MEMS structure according to the prior art. The MEMS structure is, for example, a silicon condenser microphone, and includes a substrate 110, a diaphragm layer 130 on the substrate 110, a support layer 140 on a peripheral region of the diaphragm layer 130, and a back plate 150 on the support layer 140. The MEMS structure further includes a first pad 111 contacting the diaphragm layer 130 and a second pad 112 contacting the back plate 150. The diaphragm layer 130 has a first surface opposite to the back plate 150 and a second surface exposed to an acoustic cavity formed in the substrate 110.
In the above-described MEMS structure, the pads located at different levels cause the MEMS structure to be difficult to wire in a use state and cause an excessive volume. As an improved scheme, the first bonding pad and the second bonding pad are arranged on the same layer. To this end, the second pad is located on the same level as the first pad, and the internal interconnect structure extends from the movable part to the desired level. The first bonding pad and the second bonding pad are arranged on the same layer, so that the wire leading is more convenient, and the size of a chip can be reduced. However, the above-described interconnection structure is mainly used to achieve mechanical and electrical connection functions, and may have adverse effects on the acoustic characteristics of the diaphragm.
Therefore, it is desirable to further improve the existing MEMS structure and the manufacturing method thereof to obtain a planar pad structure and improve the acoustic characteristics.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a MEMS structure and a method of manufacturing the same, in which a constraint point is provided on a diaphragm using an interconnection member, thereby improving the mode shape of the diaphragm.
According to an aspect of the invention, there is provided a MEMS structure comprising: a substrate;
a movable member located over the substrate;
a fixed member that is located on the movable member and is opposed to the movable member to form a capacitance plate;
a second pad on the fixing member;
an interconnecting member connecting the movable member levels; and
a first pad on the interconnect feature, the interconnect feature having a height difference between the first pad and the second pad of less than 10 microns.
Preferably, the MEMS structure is an MEMS microphone, the movable part and the fixed part are a diaphragm layer and a back plate of the MEMS microphone, respectively, the diaphragm layer communicates with the outside to receive a sound signal,
wherein a connection position of the interconnection member and the diaphragm layer is set according to a vibration characteristic of the diaphragm layer.
Preferably, at least part of the structure of the interconnecting part is connected with the diaphragm layer in a surface contact manner.
Preferably, the interconnecting member comprises:
a first portion on which the first pad is located;
a second portion connected in surface contact with the diaphragm layer;
a third portion connecting the first portion and the second portion.
Preferably, the first portion is disposed at an angle to the third portion;
the second portion is disposed at an angle to the third portion.
Preferably, the method further comprises the following steps:
a support layer between the diaphragm layer and the back plate,
wherein a first portion of the interconnection component extends laterally at least partially over the support layer such that the diaphragm layer is suspended beneath a second portion of the interconnection component.
Preferably, a peripheral portion of the movable member is sandwiched between the substrate and the support layer.
Preferably, the periphery of the back plate has an opening corresponding to the interconnecting member, the interconnecting member contacting the support layer within the opening.
Preferably, the first partial surface of the interconnection member is provided with a groove or a projection, and the second pad is located on the groove or the projection.
Preferably, at least a part of the first portion of the interconnecting member comprises a resilient structure.
Preferably, a part of the structure of the first portion of the interconnection component is suspended, and the elastic structure is disposed on the suspended structure of the first portion.
Preferably, the elastic structure is a groove or a bent structure.
According to another aspect of the present invention, there is provided a method of fabricating a MEMS structure, comprising: forming a movable member on a substrate; forming a support layer on the movable member; forming a first opening in the support layer; forming a first conductor layer on the support layer, wherein the first conductor layer fills the first opening; patterning the first conductor layer into an interconnection part and a fixing part; and forming first and second pads on the interconnection part and the fixed part, respectively, wherein the interconnection part and the fixed part are mechanically and electrically disconnected from each other, and the interconnection part includes a first portion extending laterally on the support layer, a second portion connected in a surface contact manner with the movable part, and a third portion connecting the first and second portions.
According to the MEMS structure provided by the embodiment of the invention, the first bonding pad of the fixed component and the second bonding pad of the movable component are positioned on the same layer by arranging the interconnection component and arranging the second bonding pad on the interconnection component, so that the process difficulty and risk of a bonding pad manufacturing link are reduced. During mass production, the height parameter of the wire bonding equipment is adjusted for a few times or even is not adjusted, and the efficiency is improved. In addition, a well-shaped structure is avoided, short circuit risks caused by the height difference of the bonding pad are eliminated, the interconnection component is used for realizing the electric connection between the first bonding pad and the vibration film layer, and meanwhile, the mechanical connection position of the interconnection component and the vibration film layer is used for optimizing the vibration mode of the vibration film layer, so that the acoustic characteristic of the MEMS microphone is improved. Since a separate constraint beam is not required, the size of the MEMS microphone can be reduced.
In a preferred embodiment, the interconnection member includes a second portion connected to the diaphragm layer in a surface contact manner, which increases the contact area of the interconnection member with the diaphragm layer and ensures reliability of mechanical and electrical connection.
In a preferred embodiment, the periphery of the back plate has an opening corresponding to the interconnection member, and the interconnection member contacts the support layer within the opening, thereby facilitating an increase in the effective facing area between the plates of the capacitor, and hence an increase in the sensitivity of the MEMS microphone.
In a preferred embodiment the diaphragm layer is at least partially suspended below the second portion of the interconnection member, thus facilitating a better mode shape and hence improved sensitivity of the MEMS microphone.
In a preferred embodiment, the first portion of the interconnecting member comprises a resilient structure. When the structure is arranged, the elasticity of the interconnection part and the vibration characteristic on the whole vibrating film layer can be adjusted by using the elastic structure, and the change of mechanical characteristics caused by the influence of the concave-convex structure arranged on the lower vibrating film layer on the profile shape of the upper back plate is not considered. Therefore, decoupling is obtained between the structural parameters, and the structural scheme can be optimized by obtaining greater convenience when the structure is arranged.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:
fig. 1a and 1b show a top view and a cross-sectional view, respectively, of a MEMS structure according to the prior art.
Fig. 2a and 2b show a top view and a cross-sectional view, respectively, of a MEMS structure according to a first embodiment of the invention.
Fig. 3a and 3b show a top view and a cross-sectional view, respectively, of a MEMS structure according to a second embodiment of the invention.
Fig. 4a and 4b show a top view and a cross-sectional view, respectively, of a MEMS structure according to a third embodiment of the invention.
Fig. 5a to 5i show cross-sectional views of stages of a method of manufacturing a MEMS structure according to a fourth embodiment of the invention, respectively.
Detailed Description
The invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by like reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale. In addition, certain well known components may not be shown. For simplicity, the semiconductor structure obtained after several steps can be described in one figure.
It will be understood that when a layer or region is referred to as being "on" or "over" another layer or region in describing the structure of the device, it can be directly on the other layer or region or intervening layers or regions may also be present. And, if the device is turned over, that layer, region, or regions would be "under" or "beneath" another layer, region, or regions.
If for the purpose of describing the situation directly above another layer, another region, the expression "a directly above B" or "a above and adjacent to B" will be used herein. In the present application, "a is directly in B" means that a is in B and a is directly adjacent to B.
In the present application, the term "MEMS structure" refers to the collective designation of the entire MEMS structure formed in the various steps of manufacturing a MEMS device, including all layers or regions that have been formed.
In the following description, numerous specific details of the invention, such as structure, materials, dimensions, processing techniques and techniques of the devices are described in order to provide a more thorough understanding of the invention. However, as will be understood by those skilled in the art, the present invention may be practiced without these specific details.
Hereinafter, a method of manufacturing the MEMS structure will be described by taking a silicon condenser microphone as an example. It will be appreciated that various types of MEMS sensors and actuators of similar construction to silicon condenser microphones can be fabricated using similar methods.
Fig. 2a and 2b show a top view and a cross-sectional view, respectively, of a MEMS structure according to a first embodiment of the invention, wherein line AA in fig. 2a shows the position of the cross-sectional view taken. The MEMS structure is, for example, a silicon condenser microphone, and includes a substrate 110, a diaphragm layer 130 located above the substrate 110, a support layer 140 located on a peripheral region of the diaphragm layer 130, and a back plate 150 located on the support layer 140.
The substrate 110 includes opposing first and second surfaces. The substrate 110 is, for example, a bulk silicon substrate, a silicon-On-insulator (SOI) substrate, a glass substrate in an sog (silicon On glass) process, etc., and in some embodiments, the substrate 110 further includes other structural layers On which functional layers of the MEMS microphone are formed.
The diaphragm layer 130 is composed of a conductive material (e.g., doped polysilicon, metal, or alloy). The diaphragm layer 130 is fixed to the substrate 110 at its peripheral portion, and the middle portion and the back plate 150 constitute the working capacitor of the MEMS microphone. The first surface of the diaphragm layer 130 is opposite to the second surface of the backplate 150, which is exposed to the acoustic cavity formed in the substrate 110. In a preferred embodiment, a sacrificial layer (not shown) is disposed between the diaphragm layer 130 and the substrate 110, and the sacrificial layer is used for reducing the stress influence of the substrate 110 on the diaphragm layer 130.
The support layer 140 is disposed between the diaphragm layer 130 and the back plate 150. The material of the support layer 140 is, for example, silicon oxide or silicon nitride. The support layer 140 is for example arranged at the periphery of the back plate 150,
the back plate 150 is comprised of a conductive material, such as doped polysilicon, a metal or an alloy. In the present embodiment, the diaphragm layer 130 and the back plate 150 are both circular. The back plate 150 has opposing first and second surfaces. A peripheral portion of the second surface of the back plate 150 is fixed to the support layer 140, and a middle portion of the second surface is opposite to a middle portion of the first surface of the diaphragm layer 130, and forms a space for accommodating a sound-transmitting medium such as air. In the silicon condenser microphone, the middle portion of the diaphragm layer 130 and the middle portion of the back plate 150 together constitute a pair of plates of a capacitor.
In operation, an external sound signal reaches the surface of the diaphragm layer 130 through the acoustic cavity, so that the diaphragm layer 130 vibrates with the sound signal, thereby changing the capacitance between the diaphragm layer 130 and the back plate 150, and converting the sound signal into an electrical signal.
Unlike the conventional MEMS structure shown in fig. 1a and 1b, the MEMS structure according to the first embodiment of the present invention further includes an interconnection member 160, the interconnection member 160 including a first portion 161 laterally extending on the surface of the support layer 140, a second portion 162 connected to the diaphragm layer 130 in a surface contact manner, and a third portion 163 connecting the first portion 161 and the second portion 162.
The first pad 111 and the second pad 112 are disposed on the interconnection member 160 and the back plate 150, respectively. The first pads 111 are electrically connected to the diaphragm layer 130 via the interconnection members 160, and the second pads 112 contact the back plate 150, thereby achieving electrical connection, respectively. Since the interconnection member 160 includes the first portion disposed on the surface of the support layer 140, the first pad 111 and the second pad 112 are both located at a level above the support layer 140, and the difference in height between the first pad 111 and the second pad 112 is guaranteed to be less than 10 micrometers, thereby obtaining a planar pad structure. In an alternative embodiment, the first portion 161 of the interconnection member 160 may further be provided with a groove or a protrusion, the first pad 111 is provided on the groove or the protrusion, and the heights of the first pad 111 and the second pad 112 are adjusted by the groove and the protrusion.
Further, the contact position of the second portion 162 of the interconnection member 160 with the diaphragm layer 130 is set according to the diaphragm constraint point, thereby achieving mechanical connection according to the vibration characteristics of the diaphragm layer 130. For example, if the desired limiting point is near the middle of the diaphragm layer, it may not be practical to provide additional constraining beams in the diaphragm layer, based on the results of the acoustic property simulation of the diaphragm 130. In contrast, with the interconnection member 160 formed on the support layer, the position where the second portion of the interconnection member 160 contacts the diaphragm layer can be precisely defined, so that a constraining point can be set at a desired diaphragm position using the mechanical connection position of the interconnection member 160.
The structure utilizes the interconnection component 160 to realize the electrical connection between the first bonding pad 111 and the diaphragm layer 130, and utilizes the mechanical connection position between the interconnection component 160 and the diaphragm layer 130 to optimize the vibration mode of the diaphragm layer, thereby improving the acoustic characteristics of the MEMS microphone. Since a separate constraint beam is not required, the size of the MEMS microphone can be reduced. The assistance of this approach is especially evident when the thickness and stress of the backplate 150 and the required range difference between the diaphragm limiting point and the diaphragm layer can be large. In addition, since the second portion 162 of the interconnection member 160 is connected to the diaphragm layer in a surface contact manner, the connection manner can increase the contact area of the interconnection member with the diaphragm layer 130, and ensure the reliability of mechanical connection and electrical connection.
In the above-described embodiment, the support layer 140 includes an outer portion for supporting the interconnection member 160, and an inner portion for supporting the back plate 150. Since the diaphragm layer 130 and the backplate 140 are circular, the outer and inner portions of the support layer 140 are concentric two rings. The first and second portions 161 and 162 of the interconnecting member 160 are each shaped like a disk, and the third portion 163 connecting the first and second portions 161 and 162 is shaped like a cylinder, and one end of the cylindrical third portion 163 is connected to the inner circumferential surface of the first portion 161 and the other end is connected to the inner circumferential surface of the second portion 162. In an alternative embodiment, if the first portion 161 of the interconnection member 160 is bar-shaped, the outer portion of the support layer 140 may be bar-shaped accordingly.
Further, in the above-described embodiment, the sound signal reaches the surface of the diaphragm layer 130 from the acoustic cavity. In an alternative embodiment, the backplate 150 is provided with a plurality of holes from which the acoustic signal reaches the surface of the diaphragm layer 130.
Fig. 3a and 3b show a top view and a cross-sectional view, respectively, of a MEMS structure according to a second embodiment of the invention, wherein line AA in fig. 3a shows the position of the cross-sectional view taken. The MEMS structure is, for example, a silicon condenser microphone, and includes a substrate 110, a diaphragm layer 130 located above the substrate 110, a support layer 140 located on a peripheral region of the diaphragm layer 131, and a back plate 150 located on the support layer 140.
Differences of the second embodiment from the first embodiment will be described below, and the same points will not be described in detail.
The MEMS structure according to the second embodiment of the present invention further includes an interconnection member 160, and the interconnection member 160 includes a first portion 161 laterally extending on the surface of the support layer 140, a second portion 162 connected with the diaphragm layer 130 in a surface contact manner, and a third portion 163 connecting the first portion 161 and the second portion 162.
The first pad 111 and the second pad 112 are disposed on the interconnection member 160 and the back plate 150, respectively. The first pads 111 are electrically connected to the diaphragm layer 131 via the interconnection member 160, and the second pads 112 contact the back plate 150, thereby achieving electrical connection, respectively. Since the interconnection member 160 includes the first portion 161 disposed on the surface of the support layer 140, the first pad 111 and the second pad 112 are both located at a level above the support layer 140, and the difference in height between the first pad 111 and the second pad 112 is guaranteed to be less than 10 μm, thereby obtaining a planar pad structure.
Further, the contact position of the second portion 162 of the interconnection member 160 with the diaphragm layer 131 is set according to the diaphragm constraint point, thereby achieving mechanical connection according to the vibration characteristics of the diaphragm layer 131. With the interconnection member 160 formed on the support layer, the position where the second portion 162 of the interconnection member 160 contacts the diaphragm layer 130 can be precisely defined, so that a constraining point can be set at a desired diaphragm position using the mechanical connection position of the interconnection member 160.
The support layer 140 includes an outer portion for supporting the interconnection member 160 and the back plate 150. Since the diaphragm layer 131 and the backplate 140 are both circular, the outer portion of the support layer 140 has a single ring shape. The first portion 161 of the interconnection member 160 has a bar shape, and the periphery of the back plate 150 has an opening 151 corresponding to the interconnection member 160. Thus, at different positions of the annular periphery, the interconnection member 160 and the backplate 150 respectively contact the support layer 140, wherein the interconnection member 160 is located in the opening 151 of the backplate 150.
Further, as shown in fig. 3b, a partial or complete mechanical break is formed between the diaphragm layer 131 and the peripheral region 132. That is, the diaphragm layer 131 may be only partially fixed or not fixed on the substrate 110, so that the interconnection member 160 at least partially suspends the diaphragm layer 131.
The structure utilizes the interconnection component 160 to realize the electrical connection between the first bonding pad 111 and the diaphragm layer 131, and utilizes the mechanical connection position between the interconnection component 160 and the diaphragm layer 131 to optimize the vibration mode of the diaphragm layer, thereby improving the acoustic characteristics of the MEMS microphone. Since a separate constraint beam is not required, the size of the MEMS microphone can be reduced. The assistance of this approach is especially evident when the thickness and stress of the backplate 150 and the required range difference between the diaphragm limiting point and the diaphragm layer can be large.
Further, this structure may be advantageous to increase an effective facing area between the plates of the capacitor by simultaneously supporting the diaphragm layer 131 and the back plate 150 outside the support layer 140. Since the diaphragm layer 131 is suspended by the interconnection member 160, a larger amplitude can be obtained under the action of the same intensity of the sound signal, thereby improving the sensitivity of the MEMS microphone.
Fig. 4a and 4b show a top view and a cross-sectional view, respectively, of a MEMS structure according to a fourth embodiment of the invention, wherein line AA in fig. 4a shows the position of the cross-sectional view taken. The MEMS structure is, for example, a silicon condenser microphone, and includes a substrate 110, a diaphragm layer 130 located above the substrate 110, a support layer 140 located on a peripheral region of the diaphragm layer 131, and a back plate 150 located on the support layer 140.
Differences of the fourth embodiment from the first embodiment will be described below, and the same points will not be described in detail.
The MEMS structure according to the fourth embodiment of the present invention further includes an interconnection member 160, and the interconnection member 160 includes a first portion 161 laterally extending on the surface of the support layer 140, a second portion 162 connected with the diaphragm layer 130 in a surface contact manner, and a third portion 163 connecting the first portion 161 and the second portion 162.
The first pad 111 and the second pad 112 are disposed on the interconnection member 160 and the back plate 150, respectively. The first pads 111 are electrically connected to the diaphragm layer 131 via the interconnection member 160, and the second pads 112 contact the back plate 150, thereby achieving electrical connection, respectively. Since the interconnection member 160 includes the first portion disposed on the surface of the support layer 140, the first pad 111 and the second pad 112 are both located at a level above the support layer 140, and the difference in height between the first pad 111 and the second pad 112 is guaranteed to be less than 10 micrometers, thereby obtaining a planar pad structure.
Further, the contact position of the third portion of the interconnection member 160 with the diaphragm layer 131 is set according to the diaphragm constraint point, thereby achieving mechanical connection according to the vibration characteristics of the diaphragm layer 131. With the interconnecting member 160 formed on the support layer, the position where the second portion 162 of the interconnecting member 160 contacts the diaphragm layer can be precisely defined, so that a constraining point can be set at a desired diaphragm position using the mechanical connection position of the interconnecting member 160.
The support layer 140 includes an outer portion for supporting the interconnection member 160 and the back plate 150. Since the diaphragm layer 131 and the backplate 140 are both circular, the outer portion of the support layer 140 has a single ring shape. The first portion of the interconnection member 160 has a bar shape, and the periphery of the back plate 150 has an opening 151 corresponding to the interconnection member 160. Thus, at different positions of the annular periphery, the interconnection member 160 and the backplate 150 respectively contact the support layer 140, wherein the interconnection member 160 is located in the opening 151 of the backplate 150.
Further, as shown in fig. 4b, a part or all of the vibrating membrane layer 131 and the peripheral region 132 are mechanically disconnected. That is, the diaphragm layer 131 may be only partially fixed or not fixed on the substrate 110, so that the interconnection member 160 at least partially suspends the diaphragm layer 131.
The structure utilizes the interconnection component 160 to realize the electrical connection between the first bonding pad 111 and the diaphragm layer 131, and utilizes the mechanical connection position between the interconnection component 160 and the diaphragm layer 131 to optimize the vibration mode of the diaphragm layer, thereby improving the acoustic characteristics of the MEMS microphone. Since a separate constraint beam is not required, the size of the MEMS microphone can be reduced. The assistance of this approach is especially evident when the thickness and stress of the backplate 150 and the required range difference between the diaphragm limiting point and the diaphragm layer can be large.
Further, this structure may be advantageous to increase an effective facing area between the plates of the capacitor by simultaneously supporting the diaphragm layer 131 and the back plate 150 outside the support layer 140. Since the diaphragm layer 131 is suspended by the interconnection member 160, a larger amplitude can be obtained under the action of the same intensity of the sound signal, thereby improving the sensitivity of the MEMS microphone.
Further, the first portion 161 of the interconnection member 160 not only extends above the support layer 140, but further includes a suspended portion, and then, the suspended portion extends to the third portion 163. The overhanging portion is provided with a resilient structure 1611, such as a groove or a bent structure, so as to adjust the elasticity of the interconnection component 160 and the vibration characteristics of the entire diaphragm layer 131 by using the resilient structure 1611, without considering that the mechanical characteristics change caused by the influence of the profile shape of the upper back plate 140 due to the concave-convex structure provided on the lower diaphragm layer. Therefore, decoupling is obtained between the structural parameters, and the structural scheme can be optimized by obtaining greater convenience when the structure is arranged.
Fig. 5a to 5i show cross-sectional views of stages of a method of manufacturing a MEMS structure according to a fifth embodiment of the invention, respectively, for manufacturing a MEMS structure according to a second embodiment of the invention. The position of these cross-sectional views is shown in figure 3a at line AA.
As shown in fig. 5a, a conductor layer 130 is deposited on the substrate 110. The substrate 110 is, for example, a monocrystalline silicon substrate, and the conductor layer 130 is, for example, composed of doped polycrystalline silicon. The deposition process is, for example, one selected from electron beam Evaporation (EBM), Chemical Vapor Deposition (CVD), Atomic Layer Deposition (ALD), sputtering.
Next, the conductive layer 130 is patterned to obtain the vibration film layer 131 and the peripheral region 132, as shown in fig. 5 b. In this embodiment, the diaphragm layer 131 and the peripheral region 132 are separated by an annular opening.
The patterning includes, for example, the steps of forming a photoresist mask and etching through openings in the mask. In patterning the conductor layer 130, an exposed portion of the conductor layer 130 is selectively removed with respect to the substrate 110 using an etchant, and etching is stopped on the surface of the substrate 110.
Next, an insulating layer is deposited on the surface of the MEMS structure, thereby forming a support layer 140, as shown in fig. 5 c. The material of the support layer 140 is, for example, silicon oxide.
Due to the pattern of the diaphragm layer 131 that has been formed, the support layer 140 not only lies in a portion above the diaphragm layer 131 and the peripheral region 132, but also fills the opening between the diaphragm layer 131 and the peripheral region 132.
Next, the supporting layer 140 is patterned to form an opening reaching the surface of the diaphragm layer 131, as shown in fig. 5 d. This opening will be used in a subsequent step to form the second and third portions 162, 163 of the interconnect.
In patterning the support layer 140, an exposed portion of the support layer 140 is selectively removed with respect to the diaphragm layer 131 using an etchant, and etching is stopped on the surface of the support layer 140.
Next, a conductor layer 152 is deposited on the surface of the MEMS structure, as shown in FIG. 5 e. The conductive layer 152 covers not only the surface of the support layer 140 but also the sidewalls and the bottom wall of the opening in the support layer 140.
The conductor layer 152 and the diaphragm layer 131 may be the same material. For example, comprised of doped polysilicon. The deposition process is, for example, one selected from electron beam Evaporation (EBM), Chemical Vapor Deposition (CVD), Atomic Layer Deposition (ALD), sputtering.
Next, the conductor layer 152 is patterned to obtain the back plate 150 and the interconnection member 160, as shown in fig. 5 f. In this embodiment, the first portion 161 of the interconnection member 160 has a bar shape, and the third portion 163 extends downward to be connected to the second portion 162.
The periphery of the back plate 150 has an opening corresponding to the interconnection member 160. Thus, at different positions of the annular periphery, the interconnection member 160 and the back plate 150 respectively contact the support layer 140, wherein the interconnection member 160 is located in the opening of the back plate 150.
The patterning includes, for example, the steps of forming a photoresist mask and etching through openings in the mask. In patterning the conductor layer 152, an exposed portion of the conductor layer 152 is selectively removed with respect to the support layer 140 using an etchant, and etching is stopped on the surface of the support layer 140.
Next, the material of the support layer 140 between the backplate 150 and the diaphragm layer 131 is removed by selective etching through the opening between the backplate 150 and the interconnection member 160, as shown in fig. 5 g. The second surface of the back plate 150 and the first surface of the diaphragm layer 131 are opposite to each other, and a space therebetween is used for accommodating a sound-transmitting medium such as air.
The etching process employs a selective etchant to remove not only the exposed portion of the support layer 140 selectively with respect to the backplate 150 and the diaphragm layer 131, but also laterally etch, removing the portion of the support layer located below the backplate 150.
Next, on the back surface of the substrate 110, an acoustic cavity is formed using etching, as shown in fig. 5 h. The acoustic cavity extends upwardly from the back surface of the substrate 110 forming a channel through the substrate 110 to the second surface of the diaphragm layer 131.
As shown in fig. 5h, the etching further etches a portion of the support layer 140 via the annular opening between the diaphragm layer 131 and the peripheral region 132, such that the first portion 161 of the interconnection member 160 further includes a dangling portion, and then extends from the dangling portion down to the diaphragm layer 131. That is, the etching simultaneously releases the diaphragm layer 131 and a portion of the interconnection member 160.
Next, the first pads 111 are formed on the surface of the interconnection member 160, and the second pads 112 are formed on the surface of the back plate 150 for external electrical connection, as shown in fig. 5 i.
In the above-described embodiments, the manufacturing method of the silicon condenser microphone is described. However, as described above, the method can be widely applied to MEMS sensors and actuators similar to the silicon condenser microphone structure.
Furthermore, in the above-described embodiments, it is described that the first portion of the interconnection member extends laterally at least partially on the support layer such that the diaphragm layer is suspended below the second portion of the interconnection member. For example, a peripheral portion of the movable member is sandwiched between the substrate and the support layer. In an alternative embodiment, the first portion of the interconnect is suspended and the second portion of the interconnect is directly connected to the movable member, so that the substrate may be omitted from the MEMS structure.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
While embodiments in accordance with the invention have been described above, these embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and their full scope and equivalents.
Claims (9)
1. A MEMS structure, comprising:
a substrate;
a diaphragm layer located above the substrate, communicating with the outside to receive an acoustic signal;
a back plate on the diaphragm layer and opposite to the diaphragm layer to form a capacitor plate;
the second bonding pad is positioned on the back polar plate;
an interconnection member connecting the diaphragm layers; and
a first pad on the interconnect feature, the interconnect feature having a height difference between the first pad and the second pad of less than 10 microns,
wherein the interconnection member and the back plate are patterned by a first conductor layer and spaced apart from each other, the interconnection member suspends the diaphragm layer and includes an elastic structure, and a connection position of the interconnection member and the diaphragm layer is set according to a constraint point of the diaphragm layer.
2. The MEMS structure of claim 1, wherein at least a portion of the structure of the interconnecting member is connected in surface contact with the diaphragm layer.
3. The MEMS structure of claim 2, wherein the interconnect member comprises:
a first portion on which the first pad is located;
a second portion connected in surface contact with the diaphragm layer;
a third portion connecting the first portion and the second portion.
4. The MEMS structure of claim 3, wherein the first portion is disposed at an angle to the third portion;
the second portion is disposed at an angle to the third portion.
5. The MEMS structure of claim 3 or 4, further comprising:
a support layer between the diaphragm layer and the back plate,
wherein a first portion of the interconnection component extends laterally at least partially over the support layer such that the diaphragm layer is suspended beneath a second portion of the interconnection component.
6. The MEMS structure of claim 5, wherein a peripheral portion of the diaphragm layer is sandwiched between the substrate and the support layer.
7. The MEMS structure of claim 5, wherein the perimeter of the back plate has an opening corresponding to the interconnect component, the interconnect component contacting the support layer within the opening.
8. The MEMS structure of claim 3, wherein at least a portion of the first portion of the interconnecting member comprises the resilient structure.
9. A method of fabricating a MEMS structure, comprising:
forming a vibration film layer on a substrate;
forming a supporting layer on the vibration film layer;
forming a first opening in the support layer;
forming a first conductor layer on the support layer, wherein the first conductor layer fills the first opening;
patterning the first conductor layer to form an interconnection member and a back plate; and
forming a first pad and a second pad on the interconnection member and the back plate, respectively,
wherein the interconnection member and the backplate are spaced apart from each other, the interconnection member suspends the diaphragm layer, and the interconnection member includes a first portion extending laterally on the support layer, a second portion connected in surface contact with the diaphragm layer, and a third portion connecting the first portion and the second portion, at least a part of the first portion of the interconnection member including a resilient structure.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101195471A (en) * | 2006-12-05 | 2008-06-11 | 中芯国际集成电路制造(上海)有限公司 | MEMS device and manufacturing method thereof |
| US7825509B1 (en) * | 2009-06-13 | 2010-11-02 | Mwm Acoustics, Llc | Transducer package with transducer die unsupported by a substrate |
| CN205051874U (en) * | 2015-11-03 | 2016-02-24 | 北京卓锐微技术有限公司 | MEMS (Micro -electromechanical system) microphone |
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| WO2015196468A1 (en) * | 2014-06-27 | 2015-12-30 | Goertek Inc. | Silicon microphone with suspended diaphragm and system with the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101195471A (en) * | 2006-12-05 | 2008-06-11 | 中芯国际集成电路制造(上海)有限公司 | MEMS device and manufacturing method thereof |
| US7825509B1 (en) * | 2009-06-13 | 2010-11-02 | Mwm Acoustics, Llc | Transducer package with transducer die unsupported by a substrate |
| CN205051874U (en) * | 2015-11-03 | 2016-02-24 | 北京卓锐微技术有限公司 | MEMS (Micro -electromechanical system) microphone |
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