CN202150936U - MEMS sensor - Google Patents
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- CN202150936U CN202150936U CN201120160329U CN201120160329U CN202150936U CN 202150936 U CN202150936 U CN 202150936U CN 201120160329 U CN201120160329 U CN 201120160329U CN 201120160329 U CN201120160329 U CN 201120160329U CN 202150936 U CN202150936 U CN 202150936U
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Abstract
An MEMS (Micro-electromechanical Systems) sensor comprises: a first plate electrode and a diaphragm, wherein first plate electrode and the diaphragm are arranged oppositely, a cavity is provided therebetween, and one side of the diaphragm is exposed in the extraneous air; and a second plate electrode arranged between the first plate electrode and the diaphragm, wherein the diaphragm and the second plate electrode are fixedly and electrically connected. The distance between the first plate electrode and the second plate electrode is relatively close, so that the plate electrodes are relatively sensitive to changes of capacitance, thus the SNR (Signal to Noise Ratio) can be raised, that is to say, the SNR of a voice signal can be raised for an MEMS microphone, and the SNR of a pressure signal can be raised for an MEMS pressure sensor.
Description
Technical field
The utility model relates to micro electronmechanical field, relates in particular to micro-electro-mechanical sensors.
Background technology
MEMS (Microelectro Mechanical Systems, be called for short MEMS) is the forward position research field of the multidisciplinary intersection that on the microelectric technique basis, grows up, is a kind of technology that adopts semiconductor technology to make micro-electro-mechanical device.Compare with traditional electromechanical device, the MEMS device has obvious advantages aspect high temperature resistant, small size, the low-power consumption.Development through decades has become one of great sciemtifec and technical sphere of attracting attention in the world, and it relates to multiple subjects such as electronics, machinery, material, physics, chemistry, biology, medical science and technology, has broad application prospects.
One of them important application of MEMS technology is the MEMS transducer, and the MEMS transducer comprises MEMS microphone, MEMS pressure sensor etc.Microphone is a kind of transducer that voice signal is converted into the signal of telecommunication.Be divided into three types of piezoelectric type, pressure resistance type and condenser types according to the difference of operation principle.Wherein the capacitance type minitype microphone is because of having higher sensitivity, lower advantages such as noise, distortion and power consumption, and becomes the main flow of micro-electro-mechanical microphone development.Pressure sensor is a kind of transducer that pressure signal is converted into the signal of telecommunication.Difference according to operation principle is divided into piezoresistive transducer and capacitance type sensor.
Fig. 1 is the schematic perspective view of existing a kind of micro-electro-mechanical microphone; Fig. 2 is the cross-sectional view of a kind of micro-electro-mechanical microphone of prior art shown in Figure 1 along the a-a direction; In conjunction with reference to figure 1 and Fig. 2; Existing a kind of micro-electro-mechanical microphone comprises: have the battery lead plate 11 of gas port, be positioned on semiconductor substrate 10 surfaces; Vibrating diaphragm 12 is oppositely arranged with battery lead plate 11, is cavity 13 between said vibrating diaphragm 12 and the battery lead plate 11; Also have back of the body chamber 14, back of the body chamber 14 lays respectively at the both sides of vibrating diaphragm 12 with cavity 13, and all is communicated with outside air, makes the air pressure of vibrating diaphragm 12 both sides identical.
Existing micro-electro-mechanical microphone operation principle is: the back of the body chamber 14 and the cavity 13 of vibrating diaphragm 12 both sides all are communicated with outside air; Therefore the pressure of vibrating diaphragm 12 both sides equates, when the gas port of sound process battery lead plate 11 reached vibrating diaphragm 12, sound wave can make vibrating diaphragm 12 vibrations; Vibration along with vibrating diaphragm 12; Electric capacity between vibrating diaphragm 12 and the battery lead plate 11 can change thereupon, and the capacitance variations between vibrating diaphragm 12 and the battery lead plate 11 is changed into the signal of telecommunication and output, promptly accomplishes the process that voice signal is converted into the signal of telecommunication.
There is following problem in existing micro-electro-mechanical microphone: at first, the distance between vibrating diaphragm 12 and the battery lead plate 11 is bigger, be not very responsive to changes in capacitance, so signal to noise ratio is bigger.Secondly; Need carry out etching to the back side of semiconductor substrate 10 owing to form back of the body chamber 14; That is to say when forming micro-electro-mechanical microphone and need all carry out etching at the front and back of substrate; Reserve certain thickness promptly need for the formation in back of the body chamber 14, can cause the thickness of semiconductor substrate 10 to increase like this; Moreover because the thickness limits of semiconductor substrate 10, the opening size in back of the body chamber 14 is difficult to dwindle, so device micro (device scaling-down) difficulty in proportion, and then causes micro-electro-mechanical microphone to be difficult to be integrated in the semiconductor chip.
The utility model content
The problem that the utility model solves is the micro-electro-mechanical sensors (comprising micro-electro-mechanical microphone and micro-electromechanical pressure transducer) of prior art, and big, the semiconductor-based plate thickness of signal to noise ratio opening size big and back of the body chamber is difficult to dwindle can't be integrated with semiconductor chip.
For addressing the above problem, the utility model provides a kind of micro-electro-mechanical sensors, comprising:
First battery lead plate, vibrating diaphragm, said first battery lead plate and said vibrating diaphragm are oppositely arranged, and are cavity between the two, and a side of said vibrating diaphragm is exposed to outside air; It is characterized in that, also comprise:
Second battery lead plate is arranged between said first battery lead plate and the said vibrating diaphragm, and said vibrating diaphragm fixedly is electrically connected with said second battery lead plate.
Compared with prior art, the utlity model has following advantage:
The micro-electro-mechanical sensors of present technique scheme; Between the vibrating diaphragm and first battery lead plate, increased by second battery lead plate, the vibrating diaphragm and second battery lead plate are fixing to be electrically connected, and the capacitance variations between the vibrating diaphragm and first battery lead plate is converted into the capacitance variations between second battery lead plate and first electrode; Because the distance between first battery lead plate and second battery lead plate is nearer relatively; Also just responsive relatively to changes in capacitance, therefore can improve signal to noise ratio, that is to say; Can improve the signal to noise ratio of voice signal for micro-electro-mechanical microphone, corresponding micro-electromechanical pressure transducer can improve the signal to noise ratio of pressure signal.
Description of drawings
Fig. 1 is the schematic perspective view of existing a kind of micro-electro-mechanical microphone;
Fig. 2 is the cross-sectional view of a kind of micro-electro-mechanical microphone of prior art shown in Figure 1 along the a-a direction;
Fig. 3 is the planar structure sketch map of the micro-electro-mechanical microphone of the utility model first specific embodiment;
Fig. 4 is a micro-electro-mechanical microphone shown in Figure 3 cross-sectional view along the b-b direction;
Fig. 5 is the flow chart of formation method of the micro-electro-mechanical microphone of the utility model first specific embodiment;
Fig. 6 a, 6b～Figure 19 a, 19b are the structural representation of formation method of the micro-electro-mechanical microphone of first specific embodiment;
Figure 20 is the planar structure sketch map of the micro-electro-mechanical microphone of the utility model second specific embodiment;
Figure 21 is a micro-electro-mechanical microphone shown in Figure 20 cross-sectional view along the c-c direction;
Figure 22 is the flow chart of formation method of the micro-electro-mechanical microphone of the utility model second specific embodiment;
Figure 23 a, Figure 23 b～Figure 33 a, Figure 33 b are the cross-sectional view of formation method of the micro-electro-mechanical microphone of second specific embodiment;
Figure 34 is the cross-sectional view of the micro-electromechanical pressure transducer of the utility model specific embodiment.
Embodiment
In order to make those skilled in the art can better understand the utility model, specify the micro-electro-mechanical microphone and the micro-electromechanical pressure transducer of the specific embodiment of the utility model below in conjunction with accompanying drawing.
In conjunction with reference to figure 3 and Fig. 4, the micro-electro-mechanical microphone of first specific embodiment comprises: first battery lead plate 41, and vibrating diaphragm 44, said first battery lead plate 41 is oppositely arranged with said vibrating diaphragm 44, is cavity 461 between the two; Also comprise: second battery lead plate 42, be arranged between said first battery lead plate 41 and the said vibrating diaphragm 44, said vibrating diaphragm 44 fixedly is electrically connected with said second battery lead plate 42.In this specific embodiment, vibrating diaphragm 44 fixedly is electrically connected with second battery lead plate 42 through plug 43.When vibrating diaphragm 44 vibrations; Can shift give second battery lead plate 42 with its vibration, so the capacitance variations between vibrating diaphragm 44 and first battery lead plate 41 is converted into the capacitance variations between second battery lead plate 42 and first battery lead plate 41, owing to the distance between first battery lead plate 41 and second battery lead plate 42 is nearer relatively; Also just responsive relatively to changes in capacitance; Therefore can improve signal to noise ratio, that is to say, can improve the signal to noise ratio of voice signal for micro-electro-mechanical microphone.
In the utility model first specific embodiment, the fixing electrical connection of the vibrating diaphragm 44 and second battery lead plate 42 in the center of vibrating diaphragm.Because it is for whole vibrating diaphragm 44, the vibration in vibrating diaphragm 44 centre positions is the most violent, just the most responsive to voice signal.With vibrating diaphragm 44 and the fixing electrical connection of second battery lead plate 42 in the centre position of vibrating diaphragm, can vibrating diaphragm 44 the strongest vibration signals be shifted to second battery lead plate 42, so just can better improve the signal to noise ratio of voice signal.
In this first specific embodiment, said first battery lead plate 41 is positioned on the substrate 30, and said vibrating diaphragm 44 is located at the side of first battery lead plate 41 away from said substrate 30 relatively.That is to say that from substrate 30 beginnings, first battery lead plate 41 is positioned on the substrate 30, second battery lead plate 42 is positioned at first battery lead plate, 41 tops, separates through cavity 461 between the two, and vibrating diaphragm 44 is above second battery lead plate 42, and both are electrically connected through plug 43.In this specific embodiment; The material of substrate 30 can be silicon substrate or silicon-on-insulator; Can be formed with metal interconnected in it or other semiconductor device (not shown)s, so that the micro-electro-mechanical microphone of the utility model can be integrated with the semiconductor chip of processing that adopts CMOS technology.
The micro-electro-mechanical microphone of this first specific embodiment also comprises: isolation structure 48, be positioned on the said substrate 30, and surround said first battery lead plate 41, second battery lead plate 42 and said vibrating diaphragm 44, be fixedly connected the said vibrating diaphragm 44 of support fixation with said vibrating diaphragm 44; Said isolation structure 48, substrate 30, first battery lead plate 41 and vibrating diaphragm 44 have surrounded cavity 461 and venting channels 462; Isolation structure 48 exceeds said vibrating diaphragm 44, has groove 45 at said isolation structure 48 away from a side of substrate 30, and said groove 45 exposes said vibrating diaphragm 44, and said vibrating diaphragm 44 is exposed in the outside air; Said isolation structure 48 has air vent hole 47, and said air vent hole 47 is communicated with said cavity 461, and said cavity 461 is communicated with said outside air.That is to say that an end of air vent hole 47 is communicated with outside air, the other end is communicated with cavity 461.In this specific embodiment; Owing to have venting channels 462 between isolation structure 48 and the said substrate 30; Said air vent hole 47, said venting channels 462, said cavity 461 threes are communicated with, and promptly cavity 461 is communicated with air vent hole 47 through venting channels 462, thereby is communicated with outside air.
The operation principle of the micro-electro-mechanical microphone of this first specific embodiment is: because vibrating diaphragm 44 is exposed in the outside air through groove 45, also is communicated with outside air at the cavity 461 of its opposite face, so the air pressure of vibrating diaphragm 44 both sides is equal.Reach 44 last times of vibrating diaphragm as sound; Vibrating diaphragm 44 vibrations also should be vibrated to shift and give second battery lead plate 42; Electric capacity between second battery lead plate 42 and first battery lead plate 41 changes along with the vibration of second battery lead plate 42; With this capacitance variations other circuit structures (this is those skilled in the art's a known technology, only quotes at this), convert capacitance variations into signal of telecommunication output through periphery.
In this first specific embodiment; Because groove 45 and cavity 461 all are formed on the same side of substrate 30; Therefore can reduce the thickness of substrate; And, the problem that the opening size in back of the body chamber can't be scaled can not appear in the prior art, also just can micro-electro-mechanical microphone be integrated in the semiconductor chip.
Need to prove that in this first specific embodiment, air vent hole 47 only is located at cavity 461 1 sides, in other embodiments, air vent hole also can be located at many sides of cavity 461 according to actual needs or be located at around it.
In this first specific embodiment, the thickness range of vibrating diaphragm 44 is 0.05 μ m～41 μ m.The material of vibrating diaphragm 44 is: the combination in any that is selected from aluminium, titanium, zinc, silver, gold, copper, tungsten, cobalt, nickel, tantalum, these metals of platinum one of them or they; Perhaps, be selected from polysilicon, amorphous silicon, poly-SiGe, these conductive non-metals of amorphous germanium silicon or their combination in any; Perhaps, be selected from said metal, conductive non-metals one of them and their combination in any and the combination of insulating barrier; Said insulating barrier is selected from silica, silicon oxynitride, silicon nitride, carbon-silicon compound and aluminium oxide one of them or theys' combination in any.
In this first specific embodiment, the thickness range of first battery lead plate 41 and second battery lead plate 42 is 0.1 μ m～4 μ m.The material of first battery lead plate 41 and second battery lead plate 42 is selected from aluminium, titanium, zinc, silver, gold, copper, tungsten, cobalt, nickel, tantalum, platinum one of them or theys' combination in any.
Each width of cloth a figure is the cross-sectional view of b figure along the b-b direction among Fig. 6 a, 6b～Figure 19 a, the 19b, in conjunction with the micro-electro-mechanical microphone formation method that specifies first specific embodiment with reference to figure 5 and Fig. 6 a, 6b～Figure 19 a, 19b.
In conjunction with reference to figure 5 and Fig. 9 a, Fig. 9 b; Execution in step S11; Substrate 30 is provided; On said substrate 30, form first battery lead plate 41, first sacrifice layer 31, second battery lead plate 42, second sacrifice layer 33 successively, said first sacrifice layer 31 covers said first battery lead plate 41 and the said substrates 30 in cover part, and said second sacrifice layer 33 covers said second battery lead plate 42, said first sacrifice layer 31 in cover part fully.Following with reference to figure 6a, Fig. 6 b～Fig. 9 a, Fig. 9 b detailed description step S11.
With reference to figure 6a and Fig. 6 b, substrate 30 is provided, on said substrate 30, form first battery lead plate 41.
With reference to figure 7a and Fig. 7 b, form first sacrifice layer 31, this first sacrifice layer 31 covers first battery lead plate 41 and cover part substrate 30 fully.With reference to figure 7b, first sacrifice layer 31 comprises two parts, is respectively sacrifice layer 311 and sacrifice layer 312.Wherein sacrifice layer 311 for after technology in form the cavity between first battery lead plate 41 and the vibrating diaphragm 44, sacrifice layer 312 for after technology in form venting channels.In this specific embodiment, the material of first sacrifice layer 31 is an amorphous carbon, and its formation method is the common chemical vapor deposition method in the CMOS technology.After forming one deck sacrifice layer on the surface of substrate 30 and first battery lead plate, 41 compositions, utilize photoetching, the graphical sacrifice layer of etching technics to form first sacrifice layer 31.Need to prove that the material of first sacrifice layer 31 is not limited to amorphous carbon, also can be for well known to a person skilled in the art other materials, but it need satisfy in the process of removing first sacrifice layer not perilesional other structures.
With reference to figure 8a and Fig. 8 b, on first sacrifice layer 41, form second battery lead plate 42.The method that forms second battery lead plate 42 is: utilize vapour deposition process on the surface that substrate 30, first sacrifice layer 41 and dielectric layer 32 are formed, to form conductive layer; Then, conductive layer is carried out flatening process; Then, utilize photoetching, etching technics patterned conductive layer to form second battery lead plate 42; Photoresist is removed in last ashing.
With reference to figure 9a and Fig. 9 b; Form second sacrifice layer 33; Cover second battery lead plate 42 fully, and cover part first sacrifice layer 31, can cover the sacrifice layer 311 of first sacrifice layer 31 fully; Also can partly cover the sacrifice layer 311 of first sacrifice layer 31, not cover the sacrifice layer 312 of first sacrifice layer 31.In diagram, the display part covers the sacrifice layer 311 of first sacrifice layer 31.In this specific embodiment, the material of second sacrifice layer 33 is an amorphous carbon, and its formation method is the common chemical vapor deposition method in the CMOS technology.After forming one deck sacrifice layer on the surface that dielectric layer 32, first sacrifice layer 31 and second battery lead plate 42 are formed, utilize photoetching, the graphical sacrifice layer of etching technics to form second sacrifice layer 33.Need to prove that the material of second sacrifice layer 33 is not limited to amorphous carbon, also can be for well known to a person skilled in the art other materials, but it need satisfy in the process of removing second sacrifice layer not perilesional other structures.
In conjunction with reference to figure 5 and Figure 13 a and Figure 13 b; Execution in step S12; In said second sacrifice layer 33, form plug 43, on said second sacrifice layer 33, form vibrating diaphragm 44, the two ends of said plug 44 are electrically connected with said second battery lead plate 42, vibrating diaphragm 44 respectively; The surface that forms first dielectric layer, 35, the first dielectric layers 35 in the outside of said second sacrifice layer 33 is surperficial equal with second sacrifice layer 33.
Below in conjunction with the step S12 in one specific embodiment being elaborated with reference to figure 10a, Figure 10 b～Figure 13 a, Figure 13 b.
With reference to figure 10a and Figure 10 b, Figure 11 a and Figure 11 b and Figure 12 a and Figure 12 b, in said second sacrifice layer 33, form plug and comprise:, in said second sacrifice layer 33, form through hole 34 with reference to figure 10a and Figure 10 b; With reference to figure 12a and Figure 12 b, form dielectric layer (among the figure not label), diffusion impervious layer (among the figure not label) successively at the sidewall of said through hole; The filled conductive material covers said diffusion impervious layer in said through hole, form plug 43.Be specially:, utilize photoetching, etching technics in second sacrifice layer 33, to form through hole 34 with reference to figure 10a and Figure 10 b.Then,, form first dielectric layer 35 with reference to figure 11a and Figure 11 b, filling vias, and other structures that form on the covered substrate 30, the surface of first dielectric layer 35 is surperficial equal with second sacrifice layer 33; The material of first dielectric layer 35 can well known to a person skilled in the art the dielectric layer material for silica, silicon oxynitride, silicon oxide carbide etc.; Utilize the chemical gaseous phase depositing process deposition to form first dielectric layer 35; Utilize flatening process planarization first dielectric layer 35 then, make surface and second sacrifice layer 33 surperficial equal of first dielectric layer 35.Afterwards; With reference to figure 12a and Figure 12 b; Utilize photoetching, etching technics to remove part first dielectric layer 35 in the through hole, reserve certain thickness first dielectric layer at the sidewall of through hole, first dielectric layer in first through hole of this reservation is the dielectric layer of through-hole side wall; Utilize the side wall deposition diffusion impervious layer of chemical vapour deposition (CVD) at through hole then, the material of diffusion impervious layer is that silicon nitride etc. well known to a person skilled in the art the material that can play the diffusion barrier effect; Fill up through hole with electric conducting material at last, form plug 43, dielectric layer, diffusion impervious layer and electric conducting material in the through hole have been formed plug 43 jointly, and electric conducting material is copper or tungsten, and its fill method is a physical vapour deposition (PVD).
With reference to figure 13a and Figure 13 b, on said second sacrifice layer 33, form vibrating diaphragm 44, the periphery of vibrating diaphragm 44 also covers on first dielectric layer 35, and this first dielectric layer 35 plays the effect of supporting vibrating diaphragm 44.The method that forms vibrating diaphragm 44 is vapour deposition, on the surface of second sacrifice layer 33 and first dielectric layer, 35 compositions, forms the vibrating diaphragm layer, and this diaphragm materials is carried out flatening process, utilizes photoetching, the graphical vibrating diaphragm layer of etching technics then, forms vibrating diaphragm 44.
In conjunction with reference to figure 5 and Figure 14, Figure 15; Execution in step S13; Form second dielectric layer 36; Cover said vibrating diaphragm 44 and said first dielectric layer 35 (with reference to Figure 14), and in said first dielectric layer 35 and second dielectric layer 36, form opening, said opening 37 exposes said first sacrifice layer 31 (with reference to Figure 15).At first, with reference to Figure 14, form second dielectric layer 36, the material that covers said vibrating diaphragm 44 and said first dielectric layer, 35, the second dielectric layers 36 is that silica, silicon oxynitride, silicon oxide carbide etc. well known to a person skilled in the art material.Its formation method does, utilizes chemical vapour deposition (CVD) to form second dielectric layer 36, then second dielectric layer 36 carried out flatening process.Then, with reference to Figure 15, in said first dielectric layer 35 and second dielectric layer 36, form opening 37, said opening 37 exposes said first sacrifice layer 31: the method that forms opening 37 is photoetching, etching technics, and behind the formation opening 37, photoresist is removed in ashing.
In conjunction with reference to figure 5 and Figure 16, execution in step S14 removes said first sacrifice layer and second sacrifice layers through said opening 37, between the vibrating diaphragm 44 and first battery lead plate 41, forms cavity 461, between said first dielectric layer 35 and substrate, forms venting channels 462.The material of first sacrifice layer and second sacrifice layer is an amorphous carbon.Comprise through said opening 37 removal first sacrifice layers and second sacrifice layer: wait ionization oxygen to form oxygen plasma; Said oxygen plasma is fed said opening, is the said amorphous carbon of ashing under 150 ℃～450 ℃ the condition in temperature range.
In conjunction with reference to figure 5 and Figure 17, execution in step S15 forms the 3rd dielectric layer 38, fills said opening 37 and covers said second dielectric layer 36.Filling opening plays the effect of sealing.The material of the 3rd dielectric layer 38 is that silica, silicon oxynitride, silicon oxide carbide etc. well known to a person skilled in the art material.Its formation method does, utilizes chemical vapour deposition (CVD) to form the 3rd dielectric layer 38, then the 3rd dielectric layer 38 carried out flatening process.
In conjunction with reference to figure 5 and Figure 18 a, Figure 18 b, Figure 19 a, Figure 19 b; Execution in step S16; In said second dielectric layer 36, the 3rd dielectric layer 38, form groove 45; Said groove 45 exposes said vibrating diaphragm 44, in institute's first dielectric layer 35, second dielectric layer 36 and said the 3rd dielectric layer 38, forms air vent hole 47, and said air vent hole 47 is communicated with said venting channels 462.Utilize photoetching, etching technics in institute's first dielectric layer 35 and said second dielectric layer 36, to form groove 45, utilize photoetching, etching technics in institute's first dielectric layer 35, said second dielectric layer 36 and the 3rd dielectric layer 38, to form air vent hole 47.
In conjunction with reference to figure 4 and Figure 19 a, and the method that forms micro-electro-mechanical microphone, can learn that isolation structure 48 is made up of dielectric layer 32, first dielectric layer 35, second dielectric layer 36 and the 3rd dielectric layer 38.
The above is the micro-electro-mechanical microphone of the utility model first specific embodiment.The micro-electro-mechanical microphone of the utility model second specific embodiment is described below.
In conjunction with reference to Figure 20 and Figure 21, the micro-electro-mechanical microphone of second specific embodiment comprises: first battery lead plate 61, and vibrating diaphragm 64, said first battery lead plate 61 is oppositely arranged with said vibrating diaphragm 64, is cavity 651 between the two; Also comprise: second battery lead plate 62, be arranged between said first battery lead plate 61 and the said vibrating diaphragm 64, said vibrating diaphragm 64 fixedly is electrically connected with said second battery lead plate 62.In this specific embodiment, vibrating diaphragm 64 fixedly is electrically connected with second battery lead plate 62 through plug 63.In the utility model second specific embodiment, the fixing electrical connection of the vibrating diaphragm 64 and second battery lead plate 62 in the center of vibrating diaphragm.
In this second specific embodiment, also comprise isolation structure 69, be positioned on the substrate 50, be fixedly connected the said vibrating diaphragm 64 of support fixation and first battery lead plate 61 respectively with first battery lead plate 61 with said vibrating diaphragm 64; Said first battery lead plate 61 is between said vibrating diaphragm 64 and said substrate 50; Between said first battery lead plate 61 and the said substrate 50 for being communicated with cavity 652; Said first battery lead plate 61 has opening (among the figure not label), and said cavity 651 is communicated with between the cavity 652 through said open communication with said; Said isolation structure 69 exceeds said vibrating diaphragm 64, has groove 67 at said isolation structure 69 away from a side of substrate 50, and said groove 67 exposes said vibrating diaphragm 64, and said vibrating diaphragm 64 is exposed in the outside air; Said isolation structure 69 has air vent hole 68, and an end of air vent hole 68 is communicated with outside air, and the other end is communicated with venting channels 66, and said air vent hole 68 is communicated with said venting channels 66, makes said cavity 651, is communicated with cavity 652 and is communicated with said outside air.In this specific embodiment; Owing to have venting channels 66 between isolation structure 69 and the said substrate 50; Said air vent hole 68, venting channels 66, said cavity 651 and be communicated with cavity 652 and be interconnected; Be that cavity 651 is communicated with air vent hole 68, thereby is communicated with outside air through connection cavity 652, venting channels 66.
The material and the thickness of first battery lead plate 61, second battery lead plate 62, vibrating diaphragm 64 are all identical with first specific embodiment, do not do at this and give unnecessary details.
In conjunction with the formation method that specifies the micro-electro-mechanical microphone of second specific embodiment with reference to Figure 22 and Figure 23 a, Figure 23 b～Figure 33 a, Figure 33 b.
In conjunction with reference to Figure 22 and Figure 23 a, Figure 23 b, execution in step S21 provides substrate 50, on said substrate 50, forms first groove 51, is communicated with 51 second groove 52 with first groove.The method of second groove 52 that on said substrate 50, form first groove 51, is communicated with first groove 51 is photoetching, etching technics.Wherein, first groove 51 after technology in, corresponding formation is communicated with cavity, second groove 52 after technology in corresponding formation venting channels.
In conjunction with reference to Figure 22 and Figure 24 a, Figure 24 b, execution in step S22 forms first sacrifice layer 53 in said first groove 51, second groove 52.
In conjunction with reference to Figure 22 and Figure 28 a, Figure 28 b; Execution in step S23; On said first sacrifice layer 53, form first battery lead plate 61 with opening, second sacrifice layer 54, second battery lead plate 62, the 3rd sacrifice layer 56 successively; Said first sacrifice layer 53 in said second sacrifice layer 54 cover parts; Before forming second battery lead plate 62, form first dielectric layer 55 in the outside of second sacrifice layer 54, the surface of said first dielectric layer 55 is surperficial equal with second sacrifice layer 54, and said the 3rd sacrifice layer 56 covers second battery lead plate 62 fully.Following with reference to figure 25a, Figure 25 b～Figure 28 a, Figure 28 b detailed description step S23.
With reference to figure 25a, Figure 25 b, on said first sacrifice layer 53, form and have opening first battery lead plate 61 of (among the figure not label).The method that forms first battery lead plate 61 is: utilize vapour deposition process on the surface that substrate 50, first sacrifice layer 53 are formed, to form conductive layer; Then, conductive layer is carried out flatening process; Then, utilize photoetching, etching technics patterned conductive layer to form first battery lead plate 61; Photoresist is removed in last ashing.Wherein, the periphery of first battery lead plate 61 can be positioned on the substrate 50, also can have only two relative edges to be positioned on the substrate 50, as long as play the effect that substrate 50 can support first battery lead plate 61.In this specific embodiment, two relative edges that first battery lead plate 61 is vertical with the c-c tangent line are positioned on the substrate 50.
With reference to figure 26a, Figure 26 b, form second sacrifice layer 54, cover said first battery lead plate 61, and cover part first sacrifice layer 53.Wherein, second sacrifice layer 54 covers first battery lead plate 61 fully, can avoid like this after technology in, when on second sacrifice layer 54, forming second battery lead plate, second battery lead plate is electrically connected with first battery lead plate 61, causes short circuit phenomenon.Second sacrifice layer 54 covers the partial sacrifice layer in first groove 51, also can cover the whole sacrifice layers in first groove 51.The material of second sacrifice layer 54 is an amorphous carbon, and its formation method is the general chemistry vapour deposition in the CMOS technology.The material of second sacrifice layer 54 also can be for well known to a person skilled in the art other materials, as long as satisfy when removing second sacrifice layer 54, other structures around not damaging get final product.
After forming second sacrifice layer 54, form first dielectric layer 55 in the outside of second sacrifice layer 54, the surface of this first dielectric layer 55 is surperficial equal with second sacrifice layer 54, and other structures on the covered substrate 50.
With reference to figure 27a, Figure 27 b; On second sacrifice layer 54, form second battery lead plate, 62, the second battery lead plates 62 and do not cover second sacrifice layer 54 fully, expose second sacrifice layer 54 at the periphery of second battery lead plate 62; After removing second sacrifice layer 54 after guaranteeing, second battery lead plate 62 can be unsettled.The method that forms second battery lead plate 62 is: utilize vapour deposition process on the surface that first dielectric layer 55, second sacrifice layer 54 are formed, to form conductive layer; Then, conductive layer is carried out flatening process; Then, utilize photoetching, etching technics patterned conductive layer to form second battery lead plate 62; Photoresist is removed in last ashing.
With reference to figure 28a, Figure 28 b, form the 3rd sacrifice layer 56, the three sacrifice layers 56 and will cover second battery lead plate 62 fully, promptly not only to cover the upper surface of second battery lead plate 62, and will cover the side of second electrode 62.The material of the 3rd sacrifice layer 56 is an amorphous carbon, and its formation method is the general chemistry vapour deposition in the CMOS technology.The material of the 3rd sacrifice layer 56 also can be for well known to a person skilled in the art other materials, as long as satisfy when removing the 3rd sacrifice layer 56, other structures around not damaging get final product.
In conjunction with reference to Figure 22 and Figure 30 a, Figure 30 b; Execution in step S24; In said the 3rd sacrifice layer 56, form plug 63, form second dielectric layer 57 in the outside of said the 3rd sacrifice layer 56, on the surface that said the 3rd sacrifice layer 56, second dielectric layer 57 and plug 63 form, form vibrating diaphragm 64; The two ends of said plug 63 are electrically connected with said second battery lead plate 62, vibrating diaphragm 64 respectively, and the periphery of said vibrating diaphragm 64 covers on said second dielectric layer 57.
With reference to figure 29a and Figure 29 b, in said the 3rd sacrifice layer 56, form plug 63, form second dielectric layer 57 in the outside of said the 3rd sacrifice layer 56.Detailed description about this step can form step plug and that outside second sacrifice layer, form dielectric layer referring among first embodiment in second sacrifice layer, this does not do detailed description, and its formation method is identical.
With reference to figure 30a and Figure 30 b, on the surface that said the 3rd sacrifice layer 56, second dielectric layer 57 and plug 63 form, form vibrating diaphragm 64, the periphery of said vibrating diaphragm 64 covers on said second dielectric layer 57.Wherein the periphery of vibrating diaphragm 64 can all cover on second dielectric layer 57, also can have only relative periphery to cover on second dielectric layer 57, as long as guarantee that second dielectric layer 57 can support vibrating diaphragm 64.In the specific embodiment of the utility model, the periphery of vibrating diaphragm 64 all covers on second dielectric layer 57.In the utility model specific embodiment, the thickness range of vibrating diaphragm 64 is 0.05 μ m～4 μ m.The method that forms vibrating diaphragm 64 is vapour deposition, on the surface that the 3rd sacrifice layer 56, second dielectric layer 57 and plug 63 are formed, forms the vibrating diaphragm layer, and this vibrating diaphragm layer is carried out flatening process, utilizes photoetching, the graphical vibrating diaphragm layer of etching technics then, forms vibrating diaphragm 64.
In conjunction with reference to Figure 22 and Figure 31; Execution in step S25; Form the 3rd dielectric layer 58; Cover said vibrating diaphragm 64, the 3rd sacrifice layer 56, second battery lead plate 62, and in said first dielectric layer 55, second dielectric layer 57 and the 3rd dielectric layer 58, form opening 581, said opening 581 exposes said first sacrifice layer 53 or second sacrifice layer 54.In this specific embodiment, for exposing first sacrifice layer 53.Certainly, in other embodiments, can also can expose second sacrifice layer 54 according to the structure of reality formation.The material of the 3rd dielectric layer 58 is that silica, silicon oxynitride, silicon oxide carbide etc. well known to a person skilled in the art material.Its formation method is: utilize chemical vapour deposition (CVD) to form the 3rd dielectric layer 58, then the 3rd dielectric layer 58 is carried out flatening process.Then, utilize photoetching, etching technics in said first dielectric layer 55, second dielectric layer 57 and the 3rd dielectric layer 58, to form opening 581, said opening 581 exposes said first sacrifice layer 53.
In conjunction with reference to Figure 22 and Figure 32; Execution in step S26 removes said first sacrifice layer, second sacrifice layer and the 3rd sacrifice layer through said opening 581, between the vibrating diaphragm 64 and first battery lead plate 61, forms cavity 651; Between first battery lead plate 61 and substrate 50, form and be communicated with cavity 652; Between said first dielectric layer 55 and substrate 50, form venting channels 66, the corresponding cavity 652 that is communicated with of said first groove, the corresponding venting channels 66 of said second groove.
In conjunction with reference to Figure 22 and Figure 33 a, Figure 33 b, execution in step S27 forms the 4th dielectric layer 59, fills said opening and covers said the 3rd dielectric layer 58; In institute's the 3rd dielectric layer 58 and said the 4th dielectric layer 59, form the 3rd groove 67 and air vent hole 68, said the 3rd groove 67 exposes said vibrating diaphragm 64, and said air vent hole 67 is communicated with said venting channels 66.
After forming the 4th dielectric layer 59; In said the 3rd dielectric layer 58, the 4th dielectric layer 59, form the 3rd groove 67; Said the 3rd groove 67 exposes said vibrating diaphragm 64; In said first dielectric layer 55, second dielectric layer 57, said the 3rd dielectric layer 58 and the 4th dielectric layer 59, form air vent hole 68, said air vent hole 68 is communicated with said venting channels 66.Utilize photoetching, etching technics in said the 3rd dielectric layer 58, the 4th dielectric layer 59, to form the 3rd groove 67, utilize photoetching, etching technics in said first dielectric layer 55, second dielectric layer 57, said the 3rd dielectric layer 58 and the 4th dielectric layer 59, to form air vent hole 68.
Need to prove, in this second specific embodiment, form the 3rd groove 67 earlier, form air vent hole 68 then.In other embodiments, also can form air vent hole 68 earlier, form the 3rd groove 67 again.And in this specific embodiment, air vent hole 68 only is positioned at a side of cavity 651, and in other embodiments, air vent hole 68 also can be formed on many sides of cavity 651.
In conjunction with reference to figure 8 and Figure 33 a, and the method that forms micro-electro-mechanical microphone, can learn that isolation structure 69 is made up of first dielectric layer 55, second dielectric layer 57, the 3rd dielectric layer 58 and the 4th dielectric layer 59.
The above just lists the specific embodiment of having lifted two limited micro-electro-mechanical microphones, and those skilled in the art can propose the embodiment of several distortion according to the enlightenment of the utility model according to its general knowledge, but does not all break away from the protection range of the utility model.
The above is the detailed description to micro-electro-mechanical microphone in the micro-electro-mechanical sensors, below the micro-electromechanical pressure transducer in the micro-electro-mechanical sensors of explanation the utility model.
Figure 34 is the cross-sectional view of the micro-electromechanical pressure transducer of the utility model specific embodiment; The structure of the micro-electro-mechanical microphone of the micro-electromechanical pressure transducer of the utility model specific embodiment and first specific embodiment is basic identical; Just lacked air vent hole and venting channels, that is to say that cavity 86 need not be communicated with outside air.With reference to Figure 34, the micro-electromechanical pressure transducer of the utility model specific embodiment comprises: first battery lead plate 81, and vibrating diaphragm 84, said first battery lead plate 81 is oppositely arranged with said vibrating diaphragm 84, is cavity 86 between the two; Also comprise: second battery lead plate 82, be arranged between said first battery lead plate 81 and the said vibrating diaphragm 84, said vibrating diaphragm 84 fixedly is electrically connected with said second battery lead plate 82.In this specific embodiment, vibrating diaphragm 84 fixedly is electrically connected with second battery lead plate 82 through plug 83.Because the distance between first battery lead plate 81 and second battery lead plate 82 is nearer relatively, also just responsive relatively to changes in capacitance, therefore can improve signal to noise ratio, that is to say, can improve the signal to noise ratio of pressure signal for micro-electromechanical pressure transducer.
In the utility model first specific embodiment, the vibrating diaphragm 84 and second battery lead plate 82 are fixed in the center of vibrating diaphragm and are electrically connected, and can better improve the signal to noise ratio of pressure signal.
In this first specific embodiment, said first battery lead plate 81 is positioned on the substrate 70, and said vibrating diaphragm 84 is located at the side of first battery lead plate 81 away from said substrate 70 relatively.
The micro-electromechanical pressure transducer of this specific embodiment also comprises: isolation structure 87, be positioned on the said substrate 70, and surround said first battery lead plate 81, second battery lead plate 82 and said vibrating diaphragm 83, be connected the said vibrating diaphragm 84 of support fixation with said vibrating diaphragm fixing 84; Said isolation structure 48, substrate 30, first battery lead plate 81 and vibrating diaphragm 84 have surrounded cavity 86; Isolation structure 87 exceeds said vibrating diaphragm 84, has groove 85 at said isolation structure 87 away from a side of substrate 70, and said groove 85 exposes said vibrating diaphragm 84, and said vibrating diaphragm 84 is exposed in the outside air.
The operation principle of the micro-electromechanical pressure transducer of this specific embodiment is: because vibrating diaphragm 84 is exposed in the outside air through groove 85; Reach 84 last times of vibrating diaphragm as pressure; Vibrating diaphragm 84 vibrations also should be vibrated to shift and give second battery lead plate 82; Electric capacity between second battery lead plate 82 and first battery lead plate 81 changes along with the vibration of second battery lead plate 82; With this capacitance variations other circuit structures (this is those skilled in the art's a known technology, only quotes at this), convert capacitance variations into signal of telecommunication output through periphery.
Those skilled in the art are according to the method for the formation micro-electro-mechanical microphone of first specific embodiment; And the similarities and differences of the structure of the micro-electro-mechanical microphone of the structure of micro-electromechanical pressure transducer and first specific embodiment; Can unquestionablely know the detailed method that forms micro-electromechanical pressure transducer by inference; Therefore, do not do detailed description at this.
Claims (9)
1. micro-electro-mechanical sensors comprises:
First battery lead plate, vibrating diaphragm, said first battery lead plate and said vibrating diaphragm are oppositely arranged, and are cavity between the two, and a side of said vibrating diaphragm is exposed to outside air; It is characterized in that, also comprise:
Second battery lead plate is arranged between said first battery lead plate and the said vibrating diaphragm, and said vibrating diaphragm fixedly is electrically connected with said second battery lead plate.
2. micro-electro-mechanical sensors as claimed in claim 1 is characterized in that, the center of said vibrating diaphragm and said second battery lead plate are electrically connected.
3. micro-electro-mechanical sensors as claimed in claim 2 is characterized in that, said micro-electro-mechanical sensors is a micro-electro-mechanical microphone; Said first battery lead plate is positioned on the substrate, and said vibrating diaphragm is located at the side of said first battery lead plate away from said substrate;
Comprise that also isolation structure is positioned on the said substrate, surround said second battery lead plate and said vibrating diaphragm, be fixedly connected, the said vibrating diaphragm of support fixation with said vibrating diaphragm; Said isolation structure, substrate, first battery lead plate and vibrating diaphragm have surrounded said cavity;
Said isolation structure exceeds said vibrating diaphragm, has groove at said isolation structure away from a side of substrate, and said groove exposes said vibrating diaphragm, and said vibrating diaphragm is exposed in the outside air;
Said isolation structure has air vent hole, and said air vent hole is communicated with said cavity, and said cavity is communicated with said outside air.
4. micro-electro-mechanical sensors as claimed in claim 2 is characterized in that, said micro-electro-mechanical sensors is a micro-electro-mechanical microphone; Also comprise isolation structure, be positioned on the substrate, be fixedly connected the said vibrating diaphragm of support fixation and first battery lead plate respectively with said vibrating diaphragm, first battery lead plate;
Said first battery lead plate is between said vibrating diaphragm and said substrate, and for being communicated with cavity, said first battery lead plate has opening between said first battery lead plate and the said substrate, and said cavity is communicated with between the cavity through said open communication with said;
Said isolation structure exceeds said vibrating diaphragm, has groove at said isolation structure away from a side of substrate, and said groove exposes said vibrating diaphragm, and said vibrating diaphragm is exposed in the outside air;
Said isolation structure has air vent hole, and said air vent hole is communicated with the said cavity that is communicated with, and said cavity, connection cavity are communicated with said outside air.
5. like claim 3 or 4 described micro-electro-mechanical sensors, it is characterized in that having venting channels between said isolation structure and the said substrate, said air vent hole, venting channels, said cavity, connection cavity are communicated with.
6. micro-electro-mechanical sensors as claimed in claim 2 is characterized in that, said micro-electro-mechanical sensors is a micro-electromechanical pressure transducer; Said first battery lead plate is positioned on the substrate, and said vibrating diaphragm is located at the side of said first battery lead plate away from said substrate;
Comprise that also isolation structure is positioned on the said substrate, surround said second battery lead plate and said vibrating diaphragm, be fixedly connected, the said vibrating diaphragm of support fixation with said vibrating diaphragm; Said isolation structure, substrate, first battery lead plate and vibrating diaphragm have surrounded said cavity;
Said isolation structure exceeds said vibrating diaphragm, has groove at said isolation structure away from a side of substrate, and said groove exposes said vibrating diaphragm, and said vibrating diaphragm is exposed in the outside air.
7. micro-electro-mechanical sensors as claimed in claim 1 is characterized in that, said vibrating diaphragm fixedly is electrically connected with said second battery lead plate through plug.
8. micro-electro-mechanical sensors as claimed in claim 1 is characterized in that,
The thickness range of said vibrating diaphragm is 0.05 μ m～4 μ m.
9. micro-electro-mechanical sensors as claimed in claim 1 is characterized in that,
The thickness range of said first battery lead plate and second battery lead plate is 0.1 μ m～4 μ m.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201120160329U CN202150936U (en) | 2011-05-18 | 2011-05-18 | MEMS sensor |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201120160329U CN202150936U (en) | 2011-05-18 | 2011-05-18 | MEMS sensor |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102249177A (en) * | 2011-05-18 | 2011-11-23 | 上海丽恒光微电子科技有限公司 | Micro-electromechanical sensor and forming method thereof |
| WO2015051729A1 (en) * | 2013-10-08 | 2015-04-16 | 无锡华润上华半导体有限公司 | Capacitive type mems pressure sensor |
| CN110749698A (en) * | 2019-09-25 | 2020-02-04 | 维沃移动通信有限公司 | Air detection device, air detection method and electronic equipment |
| CN110996786A (en) * | 2017-06-05 | 2020-04-10 | 鲍威尔曼斯菲尔德有限公司 | Transmembrane sensor for assessing neuromuscular function |
| US10623867B2 (en) | 2017-05-01 | 2020-04-14 | Apple Inc. | Combined ambient pressure and acoustic MEMS sensor |
-
2011
- 2011-05-18 CN CN201120160329U patent/CN202150936U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102249177A (en) * | 2011-05-18 | 2011-11-23 | 上海丽恒光微电子科技有限公司 | Micro-electromechanical sensor and forming method thereof |
| WO2015051729A1 (en) * | 2013-10-08 | 2015-04-16 | 无锡华润上华半导体有限公司 | Capacitive type mems pressure sensor |
| US10623867B2 (en) | 2017-05-01 | 2020-04-14 | Apple Inc. | Combined ambient pressure and acoustic MEMS sensor |
| CN110996786A (en) * | 2017-06-05 | 2020-04-10 | 鲍威尔曼斯菲尔德有限公司 | Transmembrane sensor for assessing neuromuscular function |
| CN110749698A (en) * | 2019-09-25 | 2020-02-04 | 维沃移动通信有限公司 | Air detection device, air detection method and electronic equipment |
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