CN1352515A - Monolithic integrated capacitor type silicon base micro microphone and its producing process - Google Patents
Monolithic integrated capacitor type silicon base micro microphone and its producing process Download PDFInfo
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- CN1352515A CN1352515A CN 01140441 CN01140441A CN1352515A CN 1352515 A CN1352515 A CN 1352515A CN 01140441 CN01140441 CN 01140441 CN 01140441 A CN01140441 A CN 01140441A CN 1352515 A CN1352515 A CN 1352515A
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Abstract
The invention relates to a cappacitance type tiny microphone made of intergral single chip of silicon substrate. Its characteristics are as follows. There is groove around the acoustic hole on vibrating diaphragm of upper electrode so as to reduce the stress of diaphragm greatly, moreover complex diaphragm structure is adopted, making tensile stress and compressive stress borne by the diaphragm carcel out each other. The lower electrode is made of substrate of single crystal silicon. There is an insulating layer between upper and lower electrode with air gap in middle. The structure of polysilicon/silicon nitride is used in the complex diaphragm. There is 6 structure of groove and there is a series of small concave structure support. One layer of silicon nitride protecting coats on back of electrode plate. A preposed CMOS amplifying circuit is integrated on upper end surface of substrate of single crystal silicon. The invented tiny microphone can be produced by corrosive technique of isotropy and anisotropy. It possesses merits of good sensitivity, wider frequency bandwidth, good rigidity, anti interference etc.
Description
Technical field
A kind of monolithic integrated capacitor type silicon base micro microphone and manufacture craft thereof belong to especially silicon-based micro-microphone technical field of micro-microphone.
Background technology
Micro-microphone can be realized huge microphone array easily, in hearing aid, eavesdropping, high-acruracy survey unique advantage is arranged.Silicon-based micro-microphone uses photoetching technique can accurately control figure and size, and very big repeatability is arranged on the technology, be easy to produce in batches, again can with the integrated formation micro-system of IC, will promote microphone and develop to miniaturization, low cost and high-performance direction.Traditional condenser type micro-microphone structure as shown in Figure 1.The 1st, the vibrating diaphragm of using as top electrode, the 2nd, have the back pole plate of using as bottom electrode of a lot of acoustic holes 3.Vibrating diaphragm 1 is made on the silicon substrate 4, and an insulating barrier 5 and air gap are arranged between silicon substrate 4 and the back pole plate 2.Microsensor shown in Figure 1 exists following shortcoming: 1, the sensitivity of microphone is limited by the mechanical sensitivity of vibrating diaphragm.Use the film of micro-machining preparation that very important residual stress is arranged, when thickness is reduced to a certain degree as during less than 1 μ m, can produces stress and just change (Stress Stiffening) effect, it has very big influence to the mechanical sensitivity of film.For general flat film, residual stress is big more, and mechanical sensitivity is low more, and it and technological parameter, ambient temperature, device package are all closely related, are difficult to accurate control.2, " soft back pole plate " problem.Along with dwindling of microphone size, the upper cut-off frequency that the air-flow in the air gap between back pole plate 2 and the vibrating diaphragm 1 will directly influence micro-microphone promptly influences frequency bandwidth.In order to reduce gas-flow resistance, must on back pole plate 2, open a large amount of acoustic holes, it has increased the frequency band of microphone at certain condition, but has also reduced the electric capacity of microphone simultaneously, has reduced its sensitivity; More important is the rigidity that it can reduce back pole plate 2, forms so-called " soft back pole plate ", has a strong impact on high frequency performance.Therefore, thicker rigid back pole plate 2 is the prerequisites that guarantee the system high-frequency response.Back pole plate 2 generally with the depositing technics preparation, is subjected to its thickness of internal stress influence and rigidity to be difficult to meet the demands, and process conditions are difficult to control; If the monocrystalline silicon that uses attenuate then can be done greater than 10 times of thickness as back pole plate and substrate bonding, rigidity, but apparatus expensive, heat treatment temperature is higher, and is incompatible with standard CMOS process; 3, in order to solve micro-microphone in the input capacitance of the parasitic capacitance of making and producing during encapsulation and subordinate's amplifier adverse effect to sensitivity and output waveform, also in order to solve the bigger interchange output resistance of microphone is easy to introduce noise when signal transmits problem, generally micro-microphone and amplifying circuit chip hybrid-package are reduced stray capacitance at present, the shielding outside noise, but cost of manufacture is risen.If can fine addressing this problem preamplifier and little transaudient just be integrated in the same chip, but owing to use the method for micromachined to make film on technology, to be difficult to and traditional IC process compatible; 4, the interpolar electrical breakdown of micro-microphone and the adhesion problems under mechanical force.
Summary of the invention
The objective of the invention is to propose a kind of highly sensitive, bandwidth, anti-interference strong, good output waveform again can anti-electrical breakdown and the monolithic integrated capacitor type silicon base micro microphone and the manufacture craft thereof of adhesion.
The invention is characterized in: the top electrode vibrating diaphragm has the combined type line of smooth beam bridge film for there is groove to cut apart at groove at the acoustic holes place on the film at place, the bottom electrode back pole plate has insulating barrier for what make with monocrystalline substrate between upper and lower electrode, and there is air gap the centre.Described line film is the composite membrane of polysilicon/silicon nitride structure.Described line film is uniform box structure, spider shape square structure, eight bridge circular configurations, eight bridge square structures, any structure in four bridge square structures and the four bridge circular configurations.Described line film is provided with a series of little support concave structures between its groove.Described as the monocrystalline substrate of back pole plate on deposit the silicon nitride layer of one deck protection usefulness.Integrated preposition cmos amplifier in the monocrystalline substrate upper surface that forms back pole plate.Described micro-microphone forms with isotropic etch technology when front lighting rag groove figure.Described micro-microphone forms with the anisotropy rot etching technique when front lighting rag groove figure.
Use proof: it can accomplish the end in view.
Description of drawings:
Fig. 1, the typical capacitance microphone construction schematic diagram that declines.
Fig. 2, the micro-microphone structural representation that the anisotropy rot etching technique is made with line membrane structure.
Fig. 3, the micro-microphone structural representation that isotropic etch technology is made with line membrane structure.
Fig. 4, uniform box structure formula groove distribution schematic diagram.
Fig. 5, spider shape square structure formula groove distribution schematic diagram.
Fig. 6, eight bridge circular configuration formula groove distribution schematic diagrams.
Fig. 7, eight bridge square structure formula groove distribution schematic diagrams.
Fig. 8, four bridge square structure formula groove distribution schematic diagrams.
Fig. 9, four bridge circular configuration formula groove distribution schematic diagrams.
Figure 10, monolithic integrated capacitor type micro-microphone sectional view.
Figure 11, monolithic integrated capacitor type micro-microphone manufacture craft flow chart.
Embodiment
Ask for an interview Fig. 2～Figure 10.In order to improve the mechanical sensitivity of line membrane structure, acoustic holes 3 places on back pole plate 2, line film 1 has the groove 6 of a depression, what separate groove 6 is smooth beam bridge 7, the distribution form of groove 6 and beam bridge 7 has Fig. 4～Fig. 9 totally six kinds of versions, with guarantee line film 1 and on have the back pole plate 2 of insulating barrier 5 can form upper and lower the two poles of the earth of little electric capacity of plate condenser respectively.According to finite element analysis, it is compared with the flat film with identical residual stress, and the mechanical sensitivity of line membrane structure can improve an order of magnitude.In addition, it also is diaphragm structure that this line membrane type polysilicon/silicon nitride composite membrane is called for short line film 1, the tensile stress of silicon nitride is compensated by the compression of polysilicon, and the more common silicon nitride film of its internal stress can reduce an order of magnitude, has further improved the mechanical sensitivity of film again.In order to solve " soft back pole plate " problem, with the corresponding back pole plate 2 in the bottom of line film 1 on have the air-damped while of acoustic holes 3 when reducing microphone work, use the back pole plate 2 of monocrystalline substrate as micro-microphone.Compare with the micro-microphone back pole plate 2 that forms with the thin film deposition method, this back pole plate 2 its mechanical properties of making of monocrystalline substrate are uniform and stable, thickness is not limited by stress, can accomplish thickness 10 times, have good rigidity, can avoid " soft back pole plate " harmful effect the microphone high frequency characteristics.Give the sensitivity of micro-microphone and the harmful effect that output waveform is brought for fear of distributed capacitance, also in order to reduce the interchange output resistance of micro-microphone, to reduce the noise in the signals transmission, it is integrated that preposition CMOS amplifying circuit 8 has been made monolithic simultaneously.Designed a series of little concave support structures 9 for fear of electrical breakdown between each groove 6 on the film, can be reduced in the contact area that strong sound wave is made time spent line film 1 and back pole plate 2 so greatly, it also has good effect to freely discharging of sacrifice layer simultaneously.
Goodbye Figure 11.Its corresponding technological process is as follows:
1, two-sided oxidation, heat growth SiO
2, two-sided then low-pressure chemical vapor phase deposition (LPCVD) Si
3N
4As anti-KOH corrosion layer.The Si on back of the body window surface is removed at back of the body window 10 places photoetching back side figure in the back side with reactive ion etching (RIE) method
3N
4Use buffered hydrofluoric acid solution (BHF) corrosion back of the body window region S iO again
2, this moment, silicon chip front and other parts of the back side were still by Si
3N
4Protection.With potassium hydroxide KOH corrosion back of the body forms silicon, keep about 20 μ m.Remove the Si of surface with SPA
3N
4, still keep SiO
2
2, the figure of front lighting rag groove 6 corrodes SiO with BHF
2
Can adopt KOH, anisotropic etch (2-a) and two kinds of methods not of deep reaction ion etching (DRIE) erode to projected depth, and their subsequent process steps is all identical.
Photoetching N
-Well area injects the As ion, and heat treatment under the high temperature is arrived the design well depth with the As ion propulsion that the surface is injected.
BHF removes remained on surface SiO
2, oxidation again, heat growth 1 μ mSiO
2Make insulating barrier.
3, photoetching microphone membrane district, BHF removes film district SiO
2
LPCVD deposit one deck Si
3N
4Make protective layer.
4, LPCVD deposit phosphorosilicate glass (PSG), about 2～3 μ m are made sacrifice layer and are used.
Photoetching sacrifice layer figure, BHF removes PSG.
Photoetching transistor electrodes and P+ contact hole, RIE etching Si
3N
4, BHF removes the SiO under the silicon nitride
2
The photoetching supporting construction, about 1～1.5 μ m of BHF corrosion PSG.
5, thermal oxidation 60nm is as MOS transistor grid region insulating barrier.
LPCVDO.6 μ mPolySi (polysilicon) expands phosphorus and annealing, again LPCVD one deck silicon nitride of μ m O.1.
Photoetching Poly/Si
3N
4Composite membrane, RIE etching composite membrane.Form line film 1, MOS transistor and passive resistance.
BHF removes the SiO that covers on the transistor electrodes
2, carrying out As (N type) respectively, B (P type) ion injects.
6, deposit cryogenic oxidation silicon (LTO) 0.5 μ m is as transistor cloth line insulating layer.The photoetching transistor area is with BHF etching cloth line insulating layer.
Lithography contact hole, RIE etching Si
3N
4, BHF removes LTO, forms contact hole.
Splash-proofing sputtering metal aluminium, lithography contact hole, phosphoric acid etching aluminium carries out alloy under hydrogen and nitrogen.
7, back side RIE (SF6/O2) etching single crystal silicon is to exposing the groove bottom.
The front resist coating, PSG is sacrificed in the BHF corrosion, removes photoresist.
Use unimolecule self assembly (SAM) technology at the micro-structure surface hydrophobic layer of growing.
Deionized water (DI) cleans, and is air-dry, finishes sacrifice layer and discharges.
This shows that it has the mechanical sensitivity height, good rigidly, advantages such as good, the anti-electrical breakdown of anti-interference, anti-stick company.
Claims (8)
1, a kind of monolithic integrated capacitor type silicon base micro microphone, have the back pole plate and the vibrating diaphragm and the insulating barrier that are made on the substrate of a large amount of acoustic holes above containing, it is characterized in that: the top electrode vibrating diaphragm has the combined type line of smooth beam bridge film for there is groove to cut apart at groove at the acoustic holes place on the film at place, the bottom electrode back pole plate is what make with monocrystalline substrate, between upper and lower electrode insulating barrier is arranged, there is air gap the centre.
2, according to the monolithic integrated capacitor type silicon base micro microphone of claim 1, it is characterized in that: described line film is the composite membrane of polysilicon/silicon nitride structure.
3, according to the monolithic integrated capacitor type silicon base micro microphone of claim 1, it is characterized in that: described line film is uniform box structure, spider shape square structure, eight bridge circular configurations, eight bridge square structures, any structure in four bridge square structures and the four bridge circular configurations.
4, according to the monolithic integrated capacitor type silicon base micro microphone of claim 1, it is characterized in that: described line film is provided with a series of little support concave structures between its groove.
5, according to the monolithic integrated capacitor type silicon base micro microphone of claim 1, it is characterized in that: described as the monocrystalline substrate of back pole plate on deposit the silicon nitride layer of one deck protection usefulness.
6, according to the monolithic integrated capacitor type silicon base micro microphone of claim 1, it is characterized in that: integrated preposition cmos amplifier in the monocrystalline substrate upper surface that forms back pole plate.
7, according to the monolithic integrated capacitor type silicon base micro microphone of claim 1, it is characterized in that: described micro-microphone forms with isotropic etch technology when front lighting rag groove figure.
8, according to the monolithic integrated capacitor type silicon base micro microphone of claim 1, it is characterized in that: described micro-microphone forms with the anisotropy rot etching technique when front lighting rag groove figure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011404418A CN1159950C (en) | 2001-12-07 | 2001-12-07 | Monolithic integrated capacitor type silicon base micro microphone and its producing process |
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|---|---|---|---|
| CNB011404418A CN1159950C (en) | 2001-12-07 | 2001-12-07 | Monolithic integrated capacitor type silicon base micro microphone and its producing process |
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|---|---|
| CN1352515A true CN1352515A (en) | 2002-06-05 |
| CN1159950C CN1159950C (en) | 2004-07-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB011404418A Expired - Fee Related CN1159950C (en) | 2001-12-07 | 2001-12-07 | Monolithic integrated capacitor type silicon base micro microphone and its producing process |
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Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100536608C (en) * | 2004-04-14 | 2009-09-02 | 北京大学 | Microsilicon microphone and its preparing method |
| CN101534466A (en) * | 2009-04-15 | 2009-09-16 | 无锡市纳微电子有限公司 | Silicon microphone chip and manufacture method thereof |
| CN101141832B (en) * | 2006-09-06 | 2011-04-20 | 歌尔声学股份有限公司 | Single membrane capacitance type microphone chip |
| CN1960581B (en) * | 2005-11-03 | 2011-07-13 | 歌尔声学股份有限公司 | Capacitance type silicon microphone |
| CN101355827B (en) * | 2007-07-27 | 2012-01-04 | 苏州敏芯微电子技术有限公司 | Integrated preparation method for integrated circuit and capacitance type micro-silicon microphone single slice as well as chip |
| CN102333254A (en) * | 2011-09-13 | 2012-01-25 | 华景传感科技（无锡）有限公司 | MEMS silicon microphone longitudinally integrated with CMOS circuit, and manufacturing method for the same |
| CN101107879B (en) * | 2004-10-29 | 2012-01-25 | 山东共达电声股份有限公司 | A backplateless silicon microphone |
| CN1838837B (en) * | 2006-04-11 | 2012-04-11 | 东南大学 | Minitype microphone with solid capacitance type structure |
| CN101355828B (en) * | 2007-07-27 | 2012-05-02 | 苏州敏芯微电子技术有限公司 | Monolithic integration method for integrated circuit based on SOI silicon chip and capacitance type micro-silicon microphone, and chip |
| CN101346014B (en) * | 2007-07-13 | 2012-06-20 | 清华大学 | Micro electro-mechanical system microphone and preparation method thereof |
| CN101272636B (en) * | 2007-03-21 | 2012-07-18 | 歌尔声学股份有限公司 | Capacitor type microphone chip |
| CN102079503B (en) * | 2009-11-26 | 2012-08-29 | 中芯国际集成电路制造(上海)有限公司 | Etching method of silicon substrate forming MEMS (Micro Electro Mechanical System) device |
| CN1933680B (en) * | 2005-09-14 | 2012-10-24 | 宝星电子株式会社 | Condenser microphone and packaging method for the same |
| CN101321408B (en) * | 2007-06-06 | 2012-12-12 | 歌尔声学股份有限公司 | Internal rotation beam diaphragm and microphone chip composed by the same |
| CN101321407B (en) * | 2007-06-06 | 2012-12-26 | 歌尔声学股份有限公司 | Girder-type diaphragm and microphone chip composed by the same |
| WO2013097135A1 (en) * | 2011-12-29 | 2013-07-04 | Goertek Inc. | A silicon based mems microphone, a system and a package with the same |
| CN104796831A (en) * | 2014-01-22 | 2015-07-22 | 无锡华润上华半导体有限公司 | Condenser microphone and manufacturing method thereof |
| CN114513730A (en) * | 2022-04-20 | 2022-05-17 | 苏州敏芯微电子技术股份有限公司 | Microphone assembly and electronic equipment |
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| WO2023283966A1 (en) | 2021-07-16 | 2023-01-19 | 深圳市韶音科技有限公司 | Sensing apparatus |
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- 2001-12-07 CN CNB011404418A patent/CN1159950C/en not_active Expired - Fee Related
Cited By (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100536608C (en) * | 2004-04-14 | 2009-09-02 | 北京大学 | Microsilicon microphone and its preparing method |
| CN101107879B (en) * | 2004-10-29 | 2012-01-25 | 山东共达电声股份有限公司 | A backplateless silicon microphone |
| CN101453682B (en) * | 2004-10-29 | 2013-09-11 | 山东共达电声股份有限公司 | A backplateless silicon microphone |
| CN1933680B (en) * | 2005-09-14 | 2012-10-24 | 宝星电子株式会社 | Condenser microphone and packaging method for the same |
| CN1960581B (en) * | 2005-11-03 | 2011-07-13 | 歌尔声学股份有限公司 | Capacitance type silicon microphone |
| CN1838837B (en) * | 2006-04-11 | 2012-04-11 | 东南大学 | Minitype microphone with solid capacitance type structure |
| CN101141832B (en) * | 2006-09-06 | 2011-04-20 | 歌尔声学股份有限公司 | Single membrane capacitance type microphone chip |
| CN101272636B (en) * | 2007-03-21 | 2012-07-18 | 歌尔声学股份有限公司 | Capacitor type microphone chip |
| CN101321407B (en) * | 2007-06-06 | 2012-12-26 | 歌尔声学股份有限公司 | Girder-type diaphragm and microphone chip composed by the same |
| CN101321408B (en) * | 2007-06-06 | 2012-12-12 | 歌尔声学股份有限公司 | Internal rotation beam diaphragm and microphone chip composed by the same |
| CN101346014B (en) * | 2007-07-13 | 2012-06-20 | 清华大学 | Micro electro-mechanical system microphone and preparation method thereof |
| CN101355827B (en) * | 2007-07-27 | 2012-01-04 | 苏州敏芯微电子技术有限公司 | Integrated preparation method for integrated circuit and capacitance type micro-silicon microphone single slice as well as chip |
| CN101355828B (en) * | 2007-07-27 | 2012-05-02 | 苏州敏芯微电子技术有限公司 | Monolithic integration method for integrated circuit based on SOI silicon chip and capacitance type micro-silicon microphone, and chip |
| CN101534466A (en) * | 2009-04-15 | 2009-09-16 | 无锡市纳微电子有限公司 | Silicon microphone chip and manufacture method thereof |
| CN102079503B (en) * | 2009-11-26 | 2012-08-29 | 中芯国际集成电路制造(上海)有限公司 | Etching method of silicon substrate forming MEMS (Micro Electro Mechanical System) device |
| CN102333254A (en) * | 2011-09-13 | 2012-01-25 | 华景传感科技（无锡）有限公司 | MEMS silicon microphone longitudinally integrated with CMOS circuit, and manufacturing method for the same |
| CN102333254B (en) * | 2011-09-13 | 2013-11-06 | 华景传感科技（无锡）有限公司 | MEMS silicon microphone longitudinally integrated with CMOS circuit, and manufacturing method for the same |
| CN103347808A (en) * | 2011-12-29 | 2013-10-09 | 歌尔声学股份有限公司 | A silicon based mems microphone, a system and a package with the same |
| WO2013097135A1 (en) * | 2011-12-29 | 2013-07-04 | Goertek Inc. | A silicon based mems microphone, a system and a package with the same |
| CN103347808B (en) * | 2011-12-29 | 2016-02-10 | 歌尔声学股份有限公司 | Silica-based MEMS microphone, the system comprising this microphone and encapsulation |
| US9438972B2 (en) | 2011-12-29 | 2016-09-06 | Goertek Inc. | Silicon based MEMS microphone, a system and a package with the same |
| CN104796831A (en) * | 2014-01-22 | 2015-07-22 | 无锡华润上华半导体有限公司 | Condenser microphone and manufacturing method thereof |
| CN104796831B (en) * | 2014-01-22 | 2018-10-09 | 无锡华润上华科技有限公司 | A kind of Electret Condencer Microphone and its manufacturing method |
| CN114513730A (en) * | 2022-04-20 | 2022-05-17 | 苏州敏芯微电子技术股份有限公司 | Microphone assembly and electronic equipment |
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