CN208190922U - MEMS device - Google Patents
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- CN208190922U CN208190922U CN201820576800.1U CN201820576800U CN208190922U CN 208190922 U CN208190922 U CN 208190922U CN 201820576800 U CN201820576800 U CN 201820576800U CN 208190922 U CN208190922 U CN 208190922U
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Abstract
Disclose a kind of MEMS device, wherein including the substrate with the first cavity；First sacrificial layer is located on substrate；First back pole plate layer is located on the first sacrificial layer, and at least part of the first back pole plate layer is supported by the first sacrificial layer；Second sacrificial layer is located on the first back pole plate layer；Vibrating diaphragm layer is located on the second sacrificial layer, and at least part of vibrating diaphragm layer is supported by the second sacrificial layer, so that vibrating diaphragm layer and the first back pole plate layer form first capacitor device；3rd sacrifice layer is located in vibrating diaphragm layer；Second back pole plate layer is located in 3rd sacrifice layer, and at least part of the second back pole plate layer is supported by 3rd sacrifice layer, so that the second back pole plate layer and vibrating diaphragm layer form the second capacitor.By the way that vibrating diaphragm layer is placed between the first back pole plate layer and the second back pole plate layer, be formed by two variable condensers and then forms differential type capacitance structure, meets the needs of market highly sensitive to silicon microphone, low noise, to improve the performance of MEMS device.
Description
Technical field
The utility model relates to MEMS device technical fields, more particularly, to a kind of micro- silicon microphone of capacitive MEMS
Structure.
Background technique
The micro- silicon microphone of MEMS is rapidly developed in recent years, and smart phone, laptop, bluetooth headset,
It is used widely in the consumption electronic products such as intelligent sound box.The micro- silicon microphone of MEMS mainly contains a MEMS chip and IC
Voice signal is converted into electric signal by MEMS chip by chip.Capacitance-type micro silicon microphone is by rigid perforated back pole plate and bullet
Property vibrating diaphragm constitute variable capacitance, when external sound pressure acts on vibrating diaphragm the vibration of membrane that causes to shake, so that its capacitor be made to change,
And then change the potential between vibrating diaphragm and backboard, realize the conversion of sound pressure signal and electric signal.
Currently, capacitive-type silicon microphone mostly uses greatly a vibrating diaphragm and a back board structure to constitute a variable capacitance,
Its sensitivity and signal-to-noise ratio are limited.With the fast development of the consumer products such as high-end handsets and intelligent sound box, market there is an urgent need to
Highly sensitive, low noise silicon microphone.
In the preparation process of silicon microphone, mostly carried out as sacrificial layer by HF acid or BOE solution using oxide layer
Wet etching or gas phase HF stifling method removes sacrificial oxide layer, completes the release of structure.It is a kind of existing as shown in figure 1
At least part of capacitive-type silicon microphone, back pole plate layer 501 is supported by the second sacrificial layer 401, so that vibrating diaphragm layer 301 and backplane
Plate layer 501 forms capacitor.The thickness and vibrating diaphragm layer 301 and back of the first sacrificial layer 201 between vibrating diaphragm layer 301 and substrate 100
The thickness of the second sacrificial layer 401 between pole plate layer 501 is different, however during discharging oxide layer, need excessive cross
The release that structure is completed to corrosion easily causes vibrating diaphragm layer 301 to contact with substrate 100, is unfavorable for the reliability of microphone；If
Excessive 501 region of vibrating diaphragm layer 301 and back pole plate layer is reserved on the outside of cavity, there will be biggish parasitic capacitances, and then reduce
The sensitivity of microphone.
Utility model content
Problem to be solved in the utility model is to provide a kind of MEMS device, wherein by the way that vibrating diaphragm layer to be placed on
Between first back pole plate layer and the second back pole plate layer, two variable condensers are formed by, meet market to silicon microphone height
Sensitivity, low noise demand, to improve the performance of MEMS device.
One side according to the present utility model provides a kind of MEMS device, comprising: substrate, the substrate have the first sky
Chamber；First sacrificial layer is located on the substrate, has the second cavity in first sacrificial layer；First back pole plate layer is located at institute
It states on the first sacrificial layer, at least part of the first back pole plate layer is supported by first sacrificial layer；Second sacrificial layer, position
In on the first back pole plate layer, there is third cavity in second sacrificial layer；Vibrating diaphragm layer is located at second sacrificial layer
On, at least part of the vibrating diaphragm layer is supported by second sacrificial layer, so that the vibrating diaphragm layer and first back pole plate
Layer forms first capacitor device；3rd sacrifice layer is located in the vibrating diaphragm layer, has the 4th cavity in the 3rd sacrifice layer；The
Two back pole plate layers are located in the 3rd sacrifice layer, and at least part of the second back pole plate layer is by the 3rd sacrifice layer
Support, so that the second back pole plate layer and the vibrating diaphragm layer form the second capacitor, wherein the MEMS device further includes using
In the multiple stop-layers for the lateral dimension for limiting at least one described second to the 4th cavity.
Preferably, the first back pole plate layer includes the first opening, so that second cavity and the third cavity connect
It is logical.
Preferably, the second back pole plate layer includes the second opening, so that the 4th cavity is connected to external environment.
Preferably, the multiple stop-layer includes: the first stop-layer, is located at second cavity inner wall, with described first
Stop-layer is hard mask, forms second cavity；Second stop-layer is located at the third cavity inner wall, stops with described second
Only layer is hard mask, forms the third cavity；Third stop-layer is stopped positioned at the inner wall of the 4th cavity with the third
Only layer is hard mask, forms the 4th cavity.
Preferably, first stop-layer and the first back pole plate layer surround second cavity, and described second stops
It is empty around the described 4th that layer and the vibrating diaphragm layer surround the third cavity, the third stop-layer and the second back pole plate layer
Chamber.
Preferably, first stop-layer, second stop-layer and the third stop-layer are along perpendicular to principal plane
Direction it is aligned with each other.
Preferably, further includes: passivation layer, at least cover the 3rd sacrifice layer surface and the second back pole plate layer
A part of surface of the neighbouring 3rd sacrifice layer.
Preferably, further includes: anti adhering layer, the anti adhering layer are located at first cavity, second cavity, described
The inner wall of at least one third cavity and the 4th cavity.
Preferably, further includes: the first conductive channel passes through the passivation layer, 3rd sacrifice layer, described from top to bottom
Second sacrificial layer reaches the first back pole plate layer；Second conductive channel passes through the passivation layer and the third from top to bottom
Sacrificial layer reaches the vibrating diaphragm layer；And third conductive channel, the passivation layer is passed through from top to bottom, reaches second back
Pole plate layer.
A kind of manufacturing method of MEMS device, comprising: sequentially form on substrate the first sacrificial layer, the first back pole plate layer,
Second sacrificial layer, vibrating diaphragm layer, 3rd sacrifice layer and the second back pole plate layer；The first cavity is formed in the substrate；Via institute
The first cavity to be stated, forms the second cavity in first sacrificial layer, first cavity and second cavity communicate with each other,
At least part of the first back pole plate layer is supported by first sacrificial layer；It is empty that third is formed in second sacrificial layer
At least part of chamber, the vibrating diaphragm layer is supported by second sacrificial layer, so that the vibrating diaphragm layer and first back pole plate
Layer forms first capacitor device；And the 4th cavity is formed in the 3rd sacrifice layer, at least the one of the second back pole plate layer
Part is supported by the 3rd sacrifice layer, so that the vibrating diaphragm layer and the second back pole plate layer form the second capacitor, it is described
Manufacturing method further includes forming multiple stop-layers for limiting the lateral dimension of at least one the described second to the 4th cavity.
Preferably, further includes: the first opening is formed in the first back pole plate layer, in the step for forming the third cavity
In rapid, etchant is from second cavity via the second sacrificial layer described in first opening etching.
Preferably, further includes: the second opening is formed in the second back pole plate layer, in the step for forming the 4th cavity
In rapid, etchant is via 3rd sacrifice layer described in second opening etching.
Preferably, the step of forming multiple stop-layers includes: to form first sacrificial layer and first back pole plate
Between the step of layer, first stop-layer is formed in first sacrificial layer；Forming second sacrificial layer and described
Between the step of vibrating diaphragm layer, second stop-layer is formed in second sacrificial layer；And forming the third sacrifice
Between the step of layer and the second back pole plate layer, the third stop-layer is formed in the 3rd sacrifice layer.
Preferably, first stop-layer and the first back pole plate layer surround second cavity, and described second stops
It is empty around the described 4th that layer and the vibrating diaphragm layer surround the third cavity, the third stop-layer and the second back pole plate layer
Chamber.
Preferably, first stop-layer, second stop-layer and the third stop-layer are along perpendicular to principal plane
Direction it is aligned with each other.
Preferably, after forming the second back pole plate layer, further includes: form passivation layer, at least cover the third
The surface of sacrificial layer and the second back pole plate layer are adjacent to a part of surface of the 3rd sacrifice layer.
Preferably, after the step of forming four cavity, further includes: form anti adhering layer, the anti adhering layer
Positioned at the inner wall of at least one first cavity, second cavity, the third cavity and the 4th cavity.
Preferably, after the step of forming the second back pole plate layer, further includes: the first conductive channel is formed, from upper
The passivation layer, the 3rd sacrifice layer, second sacrificial layer are passed through to lower, reaches the first back pole plate layer；Form the
Two conductive channels sequentially pass through the passivation layer and the 3rd sacrifice layer from top to bottom, reach the vibrating diaphragm layer；And it is formed
Third conductive channel passes through the passivation layer from top to bottom, reaches the second back pole plate layer.
According to the MEMS device of the utility model embodiment, by the way that vibrating diaphragm layer is placed on the first back pole plate layer and second
Between back pole plate layer, two capacitors are formed by, differential type capacitance structure is formed, the sensitive of MEMS device not only can be improved
Degree, and the signal-to-noise ratio of MEMS device can be improved, to improve the performance of MEMS device.
By the way that the first stop-layer in the first sacrificial layer, the second sacrificial layer and 3rd sacrifice layer, second will be located at respectively
Stop-layer and third stop-layer form the second cavity, third cavity and the 4th cavity, are effectively controlled as hard mask
Lateral encroaching depth, it is possible to reduce the parasitic capacitance of capacitive-type silicon microphone two sides, be conducive to improve microphone sensitivity and
Reliability.
By between substrate and the first back pole plate layer, between the first back pole plate layer and vibrating diaphragm layer, vibrating diaphragm layer with second back
Pole plate layer, the first stop-layer, the second stop-layer, third stop-layer and passivation layer all exposed surfaces on form anti-adherency
Layer, anti adhering layer is the material with hydrophobicity and low surface adhesion, can be under the premise of not influencing MEMS device performance
Reinforce the protection to MEMS device.
Detailed description of the invention
By referring to the drawings to the description of the utility model embodiment, above-mentioned and other mesh of the utility model
, feature and advantage will be apparent from, in the accompanying drawings:
Fig. 1 shows capacitive-type silicon microphone sectional view according to prior art；
Fig. 2 shows the MEMS device sectional views according to the utility model embodiment；
It is corresponding that Fig. 3 a to Fig. 3 m shows each step in the manufacturing method according to the MEMS device of the utility model embodiment
Sectional view.
Specific embodiment
Hereinafter reference will be made to the drawings is more fully described the utility model.In various figures, identical element is using similar
Appended drawing reference indicate.For the sake of clarity, the various pieces in attached drawing are not necessarily to scale.Furthermore, it is possible to be not shown
Certain well known parts.For brevity, the semiconductor structure obtained after several steps can be described in a width figure.
It should be appreciated that being known as being located at another floor, another area when by a floor, a region in the structure of outlines device
When domain " above " or " top ", can refer to above another layer, another region, or its with another layer, it is another
Also comprising other layers or region between a region.Also, if device overturn, this layer, a region will be located at it is another
Layer, another region " following " or " lower section ".
If, herein will be using " A is directly on B in order to describe located immediately at another layer, another region above scenario
The form of presentation of face " or " A on B and therewith abut ".In this application, " A is in B " indicates that A is located in B, and
And A and B is abutted directly against, rather than A is located in the doped region formed in B.
Many specific details of the utility model, such as the structure of device, material, size, place are described hereinafter
Science and engineering skill and technology, to be more clearly understood that the utility model.But just as the skilled person will understand,
The utility model can not be realized according to these specific details.
The MEMS device of the utility model embodiment is mainly used for microphone.
Fig. 2 shows the MEMS device sectional views according to the utility model embodiment.
Referring to figure 2., there is the first cavity 101 in substrate 100.First sacrificial layer 201 is located on substrate 100, and first is sacrificial
There is the second cavity 204 in domestic animal layer 201, the second cavity 204 can be corresponding with the first cavity 101, and the first cavity 101 and second is empty
Chamber 204 communicates with each other.First back pole plate layer 301 is located on the first sacrificial layer 201, at least part of the first back pole plate layer 301
It is supported by the first sacrificial layer 201, the first back pole plate layer 301 includes the first opening 302, and the first opening 302 can be used as acoustic aperture.The
Two sacrificial layers 401 are located on the first back pole plate layer 301, in the second sacrificial layer 401 have third cavity 404, third cavity 404 with
First cavity 101, the second cavity 204 are corresponding, and are connected the second cavity 204 and third cavity 404 by the first opening 302
It is logical.Vibrating diaphragm layer 501 is located on the second sacrificial layer 401, and at least part of vibrating diaphragm layer 501 is supported by the second sacrificial layer 401, so that
Vibrating diaphragm layer 501 and the first back pole plate layer 301 form first capacitor device, and vibrating diaphragm layer 501 passes through the first opening 302 and the first back pole plate
Layer 301 is connected to.3rd sacrifice layer 601 is located in vibrating diaphragm layer 501, has the 4th cavity 604 in 3rd sacrifice layer 601, and the 4th is empty
Chamber 604 is corresponding with the first cavity 101, the second cavity 204, third cavity 404.Second back pole plate layer 701 is located at 3rd sacrifice layer
On 601, at least part of the second back pole plate layer 701 is supported by 3rd sacrifice layer 601, so that vibrating diaphragm layer 501 and the second backplane
Plate layer 701 forms the second capacitor, and the second back pole plate layer 701 includes the second opening 702, and the second opening 702 can be used as acoustic aperture,
Second back pole plate layer 701 is connected to by the second opening 702 with vibrating diaphragm layer 501.
Passivation layer 801 at least cover 3rd sacrifice layer 601 surface and the second back pole plate layer 701 it is sacrificial adjacent to the third
A part of surface of domestic animal layer 601；Specifically, passivation layer 801 is located at 601 upper surface of 3rd sacrifice layer, 701 side of the second back pole plate layer
Face and at least partly upper surface of the second back pole plate layer 701.
Anti adhering layer 802 be located at the first cavity 101, the second cavity 204, third cavity 404 and the 4th cavity 604 at least it
One inner wall；Specifically, anti adhering layer 802 be located between substrate 100 and the first back pole plate layer 301, the first back pole plate layer 301 with
Between vibrating diaphragm layer 501, vibrating diaphragm layer 501 and the second back pole plate layer 701, the first stop-layer 203, the second stop-layer 403, third stop
On layer 603 and all exposed surfaces of passivation layer 801.
The first stop-layer 203 is arranged in second cavity, 204 inner wall, and the first stop-layer 203 is located at substrate 100 and the first back pole plate
Between layer 301, the second cavity 204 and the first stop-layer 203 are spaced, are hard mask with the first stop-layer 203, it is empty to form second
Chamber 204.The second stop-layer 403 is arranged in 404 inner wall of third cavity, and the second stop-layer 403 is located at the first back pole plate layer 301 and vibrating diaphragm
Between layer 501, third cavity 404 and the second stop-layer 403 are spaced, are hard mask with the second stop-layer 403, it is empty to form third
Chamber 404.Third stop-layer 603 is arranged in 4th cavity, 604 inner wall, and third stop-layer 603 is located at vibrating diaphragm layer 501 and the second back pole plate
Between layer 701, the 4th cavity 604 is spaced with third stop-layer 603, is hard mask with third stop-layer 603, it is empty to form the 4th
Chamber 604.First stop-layer 203 and the first back pole plate layer 301 limit the second cavity 204, the second stop-layer 403 and vibrating diaphragm layer 501
Third cavity 404 is limited, third stop-layer 603 and the second back pole plate layer 701 limit the 4th cavity 604.Preferably, first stops
603 layers of the 203, second stop-layer 403 of layer and third stopping are aligned with each other along the direction perpendicular to principal plane.
The MEMS device of the utility model embodiment further includes the first conductive channel 304, the second conductive channel 504 and
Three conductive channels 704.First conductive channel 304 passes through passivation layer 801,3rd sacrifice layer 601, the second sacrificial layer from top to bottom
401, reach the first back pole plate layer 301；Specifically, 304 one end of the first conductive channel reaches 301 upper surface of the first back pole plate layer,
Across the second sacrificial layer 401,3rd sacrifice layer 601, passivation layer 801 and anti adhering layer 802, so that the first conductive channel 304
The other end exposure.Second conductive channel 504 sequentially passes through passivation layer 801 and 3rd sacrifice layer 601 from top to bottom, reaches vibrating diaphragm
Layer 501；Specifically, 504 one end of the second conductive channel reaches 501 upper surface of vibrating diaphragm layer, passes through 3rd sacrifice layer 601, passivation layer
801 and anti adhering layer 802, so that the other end exposure of the second conductive channel 504.Third conductive channel 704 is worn from top to bottom
Transpassivation layer 801 reaches the second back pole plate layer 701；Specifically, 704 one end of third conductive channel reaches the second back pole plate layer 701
Upper surface passes through passivation layer 801 and anti adhering layer 802, so that the other end exposure of third conductive channel 704.
According to the MEMS device of the utility model embodiment, by by vibrating diaphragm layer 501 be placed in the first back pole plate layer 301 with
And second between back pole plate layer 701, is formed by two variable condensers, forms differential type capacitance structure, not only can be improved
The sensitivity of MEMS device, and the signal-to-noise ratio of MEMS device can be improved, to improve MEMS device performance.
By the way that be located in the first sacrificial layer 201, the second sacrificial layer 401 and 3rd sacrifice layer 601 first is stopped respectively
Only layer 203, the second stop-layer 403 and third stop-layer 603 are used as hard mask, form the second cavity 204, third cavity 404
And the 4th cavity 604, it is effectively controlled lateral encroaching depth, it is possible to reduce the parasitism electricity of capacitive-type silicon microphone two sides
Hold, is conducive to the sensitivity and reliability that improve microphone.
By between substrate 100 and the first back pole plate layer 301, between the first back pole plate layer 301 and vibrating diaphragm layer 501, vibration
Film layer 501 and the second back pole plate layer 701, the first stop-layer 203, the second stop-layer 403, third stop-layer 603 and passivation layer
Anti adhering layer 802 is formed on 801 all exposed surfaces, anti adhering layer 802 is with hydrophobicity and low surface adhesion
Material can reinforce the protection to MEMS device under the premise of not influencing MEMS device performance.
It is corresponding that Fig. 3 a to Fig. 3 m shows each step in the manufacturing method according to the MEMS device of the utility model embodiment
Sectional view.
As shown in Figure 3a, pass through thermal oxide, low-pressure chemical vapor phase deposition or plasma enhanced chemical vapor deposition
Method forms the first sacrificial layer 201 on substrate 100.First sacrificial layer 201 can be silicon dioxide layer, and thickness can be 0.5
~2 μm.Photoetching, etching are carried out to the first sacrificial layer 201, form first through hole 202, first through hole in the first sacrificial layer 201
202 can be located remotely from the position at 201 center of the first sacrificial layer.
Then, as in shown in Fig. 3 b, first through hole 202 is deposited, the first stop-layer 203 is formed.The deposition side
Method can be the method for low-pressure chemical vapor phase deposition, plasma enhanced chemical vapor deposition etc..Depositing the material formed can be with
It is silicon nitride or other suitable resistant materials.Then by the way of photoetching or etching, by the first stop-layer 203
Upper surface it is parallel with the upper surface of the first sacrificial layer 201.
Then, as in shown in Fig. 3 c, by the way of low-pressure chemical vapor phase deposition, in the first stop-layer 203 and extremely
The first back pole plate layer 301 is formed on the first sacrificial layer of small part 201.The side edge of first back pole plate layer 301 can not reach
The side edge of one sacrificial layer 201, so that the first sacrificial layer 201 is at least partly exposed by the upper surface of proximal.First backplane
Plate layer 301 can be formed by DOPOS doped polycrystalline silicon.By lithography and etching technique, the is graphically formed to the first back pole plate layer 301
One opening 302, the first opening 302 positioned at 301 layers of the first back pole plate can be used as acoustic aperture.First back pole plate layer 301 can be
Polysilicon layer, thickness can be 1.0~3.0um.
Then, as in shown in Fig. 3 d, using low-pressure chemical vapor phase deposition (LPCVD) or plasma enhanced chemical gas
The method for mutually depositing (PECVD), it is sacrificial in the upper surface of the first back pole plate layer 301, the side of the first back pole plate layer 301 and first
The upper surface of 201 exposure of domestic animal layer forms the second sacrificial layer 401.Photoetching or etching are carried out to the second sacrificial layer 401 again, second
The second through-hole 402 is formed in sacrificial layer 401, which can be located at the first opening 302 of the first back pole plate layer 301
Except and the first back pole plate layer 301 on, it is preferable that the first through hole 202 of the second through-hole 402 and the first sacrificial layer 201 is right
It answers.Second sacrificial layer 401 can be silicon dioxide layer, and thickness can be 1.0~4.0 μm.
Then, as in shown in Fig. 3 e, the second through-hole 402 is deposited, the second stop-layer 403 is formed, it is preferable that the
Two stop-layers 403 are corresponding with the first stop-layer 203.The deposition method can be the method for low-pressure chemical vapor phase deposition, plasma
Enhanced chemical vapor deposition etc..The material that deposition is formed can be silicon nitride or other suitable resistant materials.Then
It is by the way of photoetching or etching, the upper surface of the second stop-layer 403 is parallel with the upper surface of the second sacrificial layer 401.
Then, as in shown in Fig. 3 f, by the way of low-pressure chemical vapor phase deposition, in the second stop-layer 403 and extremely
Vibrating diaphragm layer 501 is formed on the second sacrificial layer of small part 401.Then it is patterned by lithography and etching technique.Vibrating diaphragm layer 501
Side edge can not reach the side edge of the second sacrificial layer 401 so that the second sacrificial layer 401 by the upper surface of proximal at least
Part exposure a, it is preferable that side edge of vibrating diaphragm layer 501 is corresponding with 301 1 side edge of the first back pole plate layer, vibrating diaphragm layer
501 another side edge does not reach another side edge of the first back pole plate layer 301.Vibrating diaphragm layer 501 can be the more of doping
Crystal silicon layer, thickness can be 0.3~1.0um.
Then, as in shown in Fig. 3 g, using low-pressure chemical vapor phase deposition (LPCVD) or plasma enhanced chemical gas
The method for mutually depositing (PECVD), in the exposure of the upper surface of vibrating diaphragm layer 501, the side of vibrating diaphragm layer 501 and the second sacrificial layer 401
Upper surface formed 3rd sacrifice layer 601.Photoetching or etching are carried out to 3rd sacrifice layer 601 again, in 3rd sacrifice layer 601
Third through-hole 602 is formed, which can be located at except the first opening 302 of the first back pole plate layer 301, Yi Jizhen
On film layer 501, it is preferable that the of the second through-hole 402 of third through-hole 602 and the second sacrificial layer 401, the first sacrificial layer 201
One through-hole 202 is corresponding.Second sacrificial layer 401 can be silicon dioxide layer, and thickness can be 1.0~4.0 μm.
Then, as in shown in Fig. 3 h, third through-hole 602 is deposited, third stop-layer 603 is formed, it is preferable that the
Three stop-layers 603 are corresponding with the first stop-layer 203, the second stop-layer 403.The deposition method can be low-pressure chemical vapor phase deposition
Method, plasma enhanced chemical vapor deposition etc..The material that deposition is formed can be silicon nitride or other are suitable resistance to
Corrosion material.Then by the way of photoetching or etching, by the upper surface of third stop-layer 603 and 3rd sacrifice layer 601
Upper surface is parallel.
Then, as in shown in Fig. 3 i, by the way of low-pressure chemical vapor phase deposition, in third stop-layer 603 and extremely
The second back pole plate layer 701 is formed in small part 3rd sacrifice layer 601.The side edge of second back pole plate layer 701 can not reach
The side edge of three sacrificial layers 601, so that 3rd sacrifice layer 601 is at least partly exposed by the upper surface of proximal, specifically, the
Two 701 1, back pole plate layer side edges do not reach the side edge of 3rd sacrifice layer 601, another side of the second back pole plate layer 701
Edge does not reach another side edge of vibrating diaphragm layer 501.Second back pole plate layer 701 can be formed by DOPOS doped polycrystalline silicon.Pass through light
Carve and etching technics, graphically form the second opening 702 to the second back pole plate layer 701, positioned at 701 layers of the second back pole plate second
Opening 702 can be used as acoustic aperture.Between third through-hole 602, i.e., the second opening 702 is located at third and stops second opening 702
Between layer 603.Preferably, the second opening 702 is corresponding with the first opening 302.First back pole plate layer 301 can be polysilicon layer,
Its thickness can be 1.0~3.0um.
Then, as in shown in Fig. 3 j, pass through the second sacrificial layer of lithography and etching 401 and 3rd sacrifice layer 601, respectively shape
At the first passage of the second back pole plate layer 701 and the second channel of vibrating diaphragm layer 501.First passage one end reaches the first back pole plate layer
301 upper surfaces pass through the second sacrificial layer 401,3rd sacrifice layer 601, so that at least partly upper surface of the first back pole plate layer 301
Exposure.Second channel one end reaches 501 upper surface of vibrating diaphragm layer, 3rd sacrifice layer 601 is passed through, so that at least portion of vibrating diaphragm layer 501
Divide upper surface exposure.
Then by techniques such as lithography and etchings, the first conductive channel 304 is formed in first passage respectively, is led to second
The second conductive channel 504 is formed in road, forms third conductive channel 704 in 701 upper surface of the second back pole plate layer.First is conductive logical
304 one end of road reaches 301 upper surface of the first back pole plate layer, the second sacrificial layer 401,3rd sacrifice layer 601 is passed through, so that first leads
The other end exposure of electric channel 304.Second conductive channel, 504 one end reaches 501 upper surface of vibrating diaphragm layer, passes through 3rd sacrifice layer
601, so that the other end exposure of the second conductive channel 504.704 one end of third conductive channel reaches positioned at the second back pole plate layer
701 upper surfaces, other end exposure.Form the first conductive channel 304, the second conductive channel 504 and third conductive channel 704
Material can be Au, and perhaps the metals such as Al are also possible to the alloys such as Cr-Au Ti-Pt-Au, are also possible to fine aluminium Al, aluminium silicon
Or Ti-TiN-Al-Si mixture etc., height can be 0.5~2um.
Then, as in shown in Fig. 3 k, using the method for plasma enhanced chemical vapor deposition (PECVD), in third
At least partly upper surface of sacrificial layer 601, the side of the second back pole plate layer 701 and the second back pole plate layer 701 forms passivation layer
801, specifically, passivation layer 801 is located at except the second opening 702 of the second back pole plate layer 701.The upper surface of passivation layer 801
Height is lower than the first conductive channel 304, the second conductive channel 504 and third conductive channel 704.Passivation layer 801 can be resistance to
Corrosion material, such as silicon nitride.
Then, as in shown in Fig. 3 l, chemically mechanical polishing CMP or reduction process are carried out to 100 lower surface of substrate, so that
The thickness of substrate 100 is suitable.Then pass through the method for dual surface lithography and etching, 100 lower surface of etched substrate, until the first sacrifice
At layer 201, the first cavity 101 is formed.First cavity 101 is located within the first stop-layer 203.
Then, as in shown in Fig. 3 m, by hydrofluoric acid or buffered oxide etch liquid (Buffered Oxide Etch,
BOE) the mode of selective wet etching is hard mask with the first stop-layer 203, and it is sacrificial first to corrode first by the first cavity 101
Domestic animal layer 201, forms the second cavity 204；It is hard mask with the second stop-layer 403, passes through the first opening of the first back pole plate layer 301
302 corrode the second sacrificial layer 401, form third cavity 404；It is hard mask with third stop-layer 603, passes through the second back pole plate
Second opening 702 of layer 701 corrodes 3rd sacrifice layer 601, the 4th cavity 604 is formed, to complete the release of structure.
Then, such as shown in Figure 2, in the first cavity 101, the second cavity 204, third cavity 404 and the 4th cavity 604
At least one inner wall formed anti adhering layer 802；Specifically, between substrate 100 and the first back pole plate layer 301, the first backplane
Between plate layer 301 and vibrating diaphragm layer 501, vibrating diaphragm layer 501 and the second back pole plate layer 701, the first stop-layer 203, the second stop-layer
403, anti adhering layer 802 is formed on third stop-layer 603 and all exposed surfaces of passivation layer 801.Anti adhering layer 802 is preferred
For one layer thin of SAM organic film or the aluminum oxide of atomic layer deposition, with a thickness of 1~10nm, which is had no effect on
The routing etc. of subsequent product is formd practical due to the hydrophobicity and low surface adhesion of SAM organic film or aluminum oxide
The anti adhering layer 802 of new embodiment MEMS device.
It should be noted that herein, relational terms such as first and second and the like are used merely to a reality
Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation
In any actual relationship or order or sequence.Moreover, the terms "include", "comprise" or its any other variant are intended to
Non-exclusive inclusion, so that the process, method, article or equipment including a series of elements is not only wanted including those
Element, but also including other elements that are not explicitly listed, or further include for this process, method, article or equipment
Intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that
There is also other identical elements in process, method, article or equipment including the element.
It is as described above according to the utility model embodiment, these embodiments details all there is no detailed descriptionthe,
Not limiting the utility model is only the specific embodiment.Obviously, as described above, can make many modifications and variations.
These embodiments are chosen and specifically described to this specification, be in order to preferably explain the principles of the present invention and practical application,
To enable skilled artisan to utilize the utility model and modification on the basis of the utility model well
It uses.The utility model is limited only by the claims and their full scope and equivalents.
Claims (9)
1. a kind of MEMS device characterized by comprising
Substrate, the substrate have the first cavity；
First sacrificial layer is located on the substrate, has the second cavity in first sacrificial layer；
First back pole plate layer is located on first sacrificial layer, and at least part of the first back pole plate layer is by described first
Sacrificial layer support；
Second sacrificial layer is located on the first back pole plate layer, has third cavity in second sacrificial layer；
Vibrating diaphragm layer is located on second sacrificial layer, and at least part of the vibrating diaphragm layer is supported by second sacrificial layer, is made
It obtains the vibrating diaphragm layer and the first back pole plate layer forms first capacitor device；
3rd sacrifice layer is located in the vibrating diaphragm layer, has the 4th cavity in the 3rd sacrifice layer；
Second back pole plate layer is located in the 3rd sacrifice layer, and at least part of the second back pole plate layer is by the third
Sacrificial layer support, so that the second back pole plate layer and the vibrating diaphragm layer form the second capacitor,
Wherein, the MEMS device further includes for limiting the multiple of the lateral dimension of at least one the described second to the 4th cavity
Stop-layer.
2. MEMS device according to claim 1, which is characterized in that the first back pole plate layer includes the first opening, is made
Second cavity is obtained to be connected to the third cavity.
3. MEMS device according to claim 1, which is characterized in that the second back pole plate layer includes the second opening, is made
The 4th cavity is obtained to be connected to external environment.
4. MEMS device according to claim 1, which is characterized in that the multiple stop-layer includes:
First stop-layer is located at second cavity inner wall, and using first stop-layer as hard mask, it is empty to form described second
Chamber；
Second stop-layer is located at the third cavity inner wall, and using second stop-layer as hard mask, it is empty to form the third
Chamber；
Third stop-layer, using the third stop-layer as hard mask, it is empty to form the described 4th positioned at the inner wall of the 4th cavity
Chamber.
5. MEMS device according to claim 4, which is characterized in that first stop-layer and the first back pole plate layer
Around second cavity, second stop-layer and the vibrating diaphragm layer surround the third cavity, the third stop-layer and
The second back pole plate layer surrounds the 4th cavity.
6. MEMS device according to claim 4, which is characterized in that first stop-layer, second stop-layer and
The third stop-layer is aligned with each other along the direction perpendicular to principal plane.
7. MEMS device according to claim 1, which is characterized in that further include: it is sacrificial at least to cover the third for passivation layer
The surface of domestic animal layer and the second back pole plate layer are adjacent to a part of surface of the 3rd sacrifice layer.
8. MEMS device according to claim 1, which is characterized in that further include:
Anti adhering layer, the anti adhering layer are located at first cavity, second cavity, the third cavity and the described 4th
The inner wall of at least one cavity.
9. MEMS device according to claim 7, which is characterized in that further include:
First conductive channel passes through the passivation layer, the 3rd sacrifice layer, second sacrificial layer from top to bottom, reaches institute
State the first back pole plate layer；
Second conductive channel passes through the passivation layer and the 3rd sacrifice layer from top to bottom, reaches the vibrating diaphragm layer；And
Third conductive channel passes through the passivation layer from top to bottom, reaches the second back pole plate layer.
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| CN201820576800.1U CN208190922U (en) | 2018-04-20 | 2018-04-20 | MEMS device |
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| CN201820576800.1U CN208190922U (en) | 2018-04-20 | 2018-04-20 | MEMS device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108600928A (en) * | 2018-04-20 | 2018-09-28 | 杭州士兰集成电路有限公司 | MEMS device and its manufacturing method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108600928A (en) * | 2018-04-20 | 2018-09-28 | 杭州士兰集成电路有限公司 | MEMS device and its manufacturing method |
| CN108600928B (en) * | 2018-04-20 | 2024-05-31 | 杭州士兰集成电路有限公司 | MEMS device and method of manufacturing the same |
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