KR101112120B1 - Micro-Electro Mechanical System microphone and Manufacturing Method thereof - Google Patents

Abstract

The present invention is easy to manufacture even using the bulk micromachining (bulk micromachining) technology, it is possible to shorten the manufacturing time, to ensure a high yield, surface mount technology (SMT) process can be applied, by the ultra-thin configuration It relates to a MEMS microphone capable of producing a large amount and a method of manufacturing the same. To this end, the MEMS microphone according to the present invention comprises a substrate; An acoustic chamber formed on top of the substrate; A plurality of support zones formed inside the acoustic chamber; An electrode plate formed on the bottom surface of the acoustic chamber; And a diaphragm supported by the plurality of supporting zones and formed above the electrode plate.

Integrated diaphragm, integrated electrode plate, MEMS microphone

Description

MEMS microphone and its manufacturing method {Micro-Electro Mechanical System microphone and Manufacturing Method

The present invention relates to a MEMS (Micro-Electro Mechanical System, MEMS) microphone, and more particularly, ultra-thin and highly sensitive surface mount technology (SMT) applicable silicon microphone manufactured by the surface micromachining method (surface micromachining) and It is about the manufacturing method.

Until now, researches related to MEMS (Micro-Electro Mechanical System) microphones have been mainly divided into resistance type, piezo type, and condenser type.

Since the resistance type MEMS microphone uses the principle that the resistance value is changed by vibration, the resistance value is changed according to the change of the surrounding environment (temperature, humidity, dust, etc.), and thus there is a disadvantage in that it cannot maintain a constant frequency range.

Piezoelectric MEMS microphones use the piezo effect, which produces a potential difference across the diaphragm, so that the electrical signal changes depending on the pressure of the voice signal, but the low band and voice band frequency characteristics are uneven. This is extremely limited.

Condenser type MEMS microphones have air gaps between several micrometers and several tens of micrometers between two electrodes so that one metal plate of two metal plates can be used as a back plate and the other diaphragm can vibrate in response to an acoustic signal. Since the diaphragm vibrates according to the sound source, the capacitance changes between the fixed electrodes, the accumulated charge changes, and thus the current flows according to the stability and frequency characteristics of the converted sound range.

In addition, the material of the diaphragm is a polymer-based film, so it is impossible to apply the surface mount technology (SMT) at high temperature for mass production by reducing manufacturing cost and precision of the parts, and bulk type bulk processing -type micromachining) has the disadvantages of long process time and yield reduction, but MEMS microphone has been developed and produced mainly as a condenser type because of its excellent frequency response in voice band.

However, there is an urgent need for the production of MEMS microphones that can be surface-mounted as demand for miniaturization and automation of microphones and increased manufacturing costs is increased.

Figure 1 shows the structure of a conventional MEMS microphone.

Referring to FIG. 1, a sacrificial layer 50 for forming a gap 40 between a fixed electrode 20 and a lower electrode 30 formed on an arbitrary substrate 10 is formed to have a predetermined thickness, and a sacrificial layer 50 is formed. ) Once all removal processes are completed, the voids 40 are completed.

Here, an insulating film is used between the fixed electrode 20 and the lower electrode 30 to prevent disconnection between the electrodes, and electrode pads used as the electrodes are formed on the substrate 10 at regular intervals.

In general, a condenser type MEMS microphone fabricates a fixed electrode 20 and a lower electrode 30 fixed to an upper portion of a substrate, and protects an upper portion with an insulator to form a rear acoustic chamber 60 under the substrate and then lowers the substrate. More than a few hundred μm is processed, and after the copper process goes through the process of removing the upper sacrificial layer. After the rear acoustic chamber 60 is processed, the fabrication process is completed by removing the sacrificial layer 50 between the lower electrodes 30 through the holes of the fixed electrode 20.

As described above, the conventional condenser-type microphones require a semiconductor process on both the upper and lower portions of the substrate in order to form a rear acoustic chamber. Therefore, the manufacturing process is large, complicated, and the processing time is long. There is a vulnerability that is low.

In addition, the selection of process materials by the same process is limited, so there is a limit in producing products suitable for the SMT process, which cannot meet the SMD component demand of the market.

SUMMARY OF THE INVENTION An object of the present invention is to provide a MEMS microphone capable of shortening the manufacturing process and manufacturing time by overcoming and improving the complicated processability of the conventional condenser microphone and integrating the acoustic chamber, which is usually located behind the lower electrode, on the upper substrate. And to provide a method for producing the same.

Another object of the present invention is to form a hemispherical step using a thermal oxide film on the bottom surface of the acoustic chamber, and to form a lower electrode plate on the upper side to smoothly discharge the air flow to the vibration of the diaphragm generated by external sound. To minimize the distance between the upper diaphragm and the lower electrode plate by the step to provide an ultra-thin MEMS microphone for SMT having excellent frequency response characteristics and a method of manufacturing the same.

MEMS microphone according to embodiments of the present invention for achieving the above object is a substrate; An acoustic chamber formed on top of the substrate; A plurality of support zones formed inside the acoustic chamber; An electrode plate formed on the bottom surface of the acoustic chamber; And a diaphragm supported by the plurality of supporting zones and formed above the electrode plate.

The diaphragm may include a plurality of through holes.

The microphone further comprises a plurality of auxiliary supports formed between the plurality of support zones to support the diaphragm.

The acoustic chamber, the plurality of supports and the plurality of auxiliary supports are formed integrally with the substrate by etching the substrate.

The substrate is characterized in that made of a silicon material.

The acoustic chamber, the plurality of supports and the plurality of auxiliary supports may include a nitride film formed on a surface thereof.

The plurality of supports and the plurality of auxiliary supports may include an oxide film formed below the nitride film from above.

The acoustic chamber may further include a protrusion formed between the electrode plate and the bottom surface.

The protrusion is an oxide film formed to protrude in a hemispherical shape from the center of the bottom surface of the acoustic chamber.

The diaphragm has a plurality of first contact terminals protruding from the edge and formed integrally.

The electrode plate is characterized in that it has an integral second contact terminal extending from the edge.

The plurality of supporting zones are formed to be adjacent to the electrode plate on the lower side.

One of the plurality of through holes is formed at the center of the diaphragm, and the other is formed at the edge of the diaphragm.

The diaphragm and the electrode plate may be a metal film formed of any one material of Ti, Au, Cu, Al, Pt, and TiN.

MEMS microphone manufacturing method according to embodiments of the present invention for achieving the above object comprises the steps of: a) forming an acoustic chamber and a plurality of support zones on the upper surface of the substrate; b) forming an electrode plate in the center of the bottom surface of the acoustic chamber; c) forming a sacrificial layer on an upper surface of the substrate and on the acoustic chamber; d) forming a diaphragm supported by the support zone above the electrode plate after removing the upper portion of the sacrificial layer; And e) removing the sacrificial layer.

In the step d), a plurality of through holes are formed in the diaphragm.

In step d), one of the plurality of through holes is formed in the central portion, the remaining through holes are characterized in that formed in the edge.

In the step a), a plurality of auxiliary supports are formed between the plurality of support zones.

The step a) may include forming an oxide film on the surface of the substrate; Forming the acoustic chamber, the plurality of support zones, and the plurality of auxiliary supports by etching after patterning the oxide film; And forming a nitride film on surfaces of the acoustic chamber, the plurality of support zones, and the plurality of auxiliary supports.

In the step a), the plurality of support zones and the plurality of auxiliary supporters are formed inside the acoustic chamber, and are characterized in that the heights of both the supporters are the same.

The step b) may include forming a hemispherical oxide film after removing the nitride film in the center of the acoustic chamber; And forming the electrode plate, which is a metal film, on the hemispherical oxide film.

The diaphragm and the electrode plate are metal films formed by a metal sputtering technique, and are made of any one material of Ti, Au, Cu, Al, Pt, and TiN.

The diaphragm and the electrode plate are formed at an edge to form an integrated contact terminal for power supply.

In the step a), the plurality of support zones are formed to be adjacent to the electrode plate on the lower side.

In the step c), the sacrificial layer is formed to cover the plurality of the support, the plurality of auxiliary support and the acoustic chamber to a thickness of more than 1 times to 1.5 times the depth of the acoustic chamber.

In the step d), the upper portion of the sacrificial layer is removed so that the nitride film on the upper surface of the plurality of support and the plurality of auxiliary support is exposed.

The sacrificial layer may be a material that is easily etched by an isotropic etching gas including at least poly-silicon-based plasma.

MEMS microphones and a method of manufacturing the same according to embodiments of the present invention improve the production yield by forming a single-sided microphone that simplifies the structure of the MEMS microphone and the complicated semiconductor process applied to the upper and lower substrates. It has the effect of studying the stability.

In addition, the MEMS microphone according to the embodiments of the present invention and a method of manufacturing the same can be arranged in the same substrate through the ease of the process, it is possible to place thousands of chips in the silicon substrate (chip) There is an effect that can dramatically reduce the production cost of the applied parts through production.

In addition, the MEMS microphone and its manufacturing method according to the embodiments of the present invention can replace the electret material with silicon rather than polymer, compared to the conventional products, it is possible to enhance the durability and SMD components having excellent sensitivity characteristics It can be effective.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related well-known configuration or function may obscure the gist of the present invention, the detailed description will be omitted, and the singular terminology may include a plurality of concepts. have. In addition, the following will describe a preferred embodiment of the present invention, but the technical idea of the present invention is not limited thereto and may be variously modified and modified by those skilled in the art.

Figure 2 (a) is a front view of the MEMS microphone projecting the structure of the upper diaphragm and the lower portion according to an embodiment of the present invention, each of Figures 2 (b) and (c) is a cutting line A1-A1 A cross-sectional view taken along 'and B1-B1' is shown.

Referring to Figures 2 (a) to (c), according to an embodiment of the present invention, the MEMS microphone 200 includes a substrate 210; An acoustic chamber 220 formed on the top of the substrate; A plurality of support zones 230 formed in the acoustic chamber; An electrode plate 260 formed on the bottom surface of the acoustic chamber; And a diaphragm 270 supported by the plurality of supporting zones and formed above the electrode plate.

The microphone 200 may further include a plurality of auxiliary supports 240 formed between the plurality of support zones to support the diaphragm. The diaphragm 270 and the electrode plate 260 are metal films formed of any one of Ti, Au, Cu, Al, Pt, and TiN. The plurality of auxiliary supports 240 function to prevent the diaphragm from sagging or sticking down by vertical movement.

The acoustic chamber 220, the plurality of support supports 230, and the plurality of auxiliary supports 240 are integrally formed with the substrate by etching the substrate made of silicon material, and the plurality of supports and the plurality of auxiliary supports are formed. The support is formed to have the same height in the acoustic chamber 220. The etching is performed by silicon wet etching using TMAH or KOH or a silicon (Si) etching solution corresponding thereto, and is performed by a surface micromachining technique having a fine step of 0.5 μm to several μm.

A nitride film 221 is formed on a surface of the acoustic chamber, the plurality of supports, and the plurality of auxiliary supports, and the plurality of supports and the plurality of auxiliary supports are formed of the nitride film of a portion supporting the upper diaphragm 270. An oxide film 211 is further provided below 221. That is, the plurality of supports and the plurality of auxiliary supports have a double insulating film formed of Si02 and Si3N4 on the upper and outer peripheral surfaces.

The plurality of support zones are designed and arranged so that the air flow generated as the diaphragm 270 is driven by the sound source can be smoothly discharged and dispersed, and the upper portion of the substrate 210 is wet etched to allow the inside of the substrate to be wet-etched. An acoustic chamber 220 is formed in the electrode plate, and the electrode plate 260 is formed on an inner bottom surface of the acoustic chamber. In this case, the electrode plate 260 has a hemispherical shape with an optional thickness on the center bottom surface of the acoustic chamber, which is the lower part of the electrode plate, in adjusting the distance from the diaphragm 270 to secure excellent frequency response characteristics. The oxide film 250 is grown.

Also, referring to FIGS. 5D and 5E, after forming the silicon sacrificial layers 410 and 420 that are higher than the heights of the plurality of supports for forming the diaphragm 270, the upper portions of the plurality of support zones are formed. The sacrificial layer 420 is removed through a surface processing technique to the same surface 411 as the nitride film layer formed on the surface. Here, the two sacrificial layers 410 and 420 separated by the solid lines in FIG. 5 (d) are formed by one process and are not physically divided. The solid line in FIG. 5 (d) is an imaginary line to help understand where the sacrificial layer should be removed to form the diaphragm.

The diaphragm 270 is driven by a sound source, and is formed of a metal material having a thickness of 1000 μm to several μm, and may be made of Ti, Au, Cu, Al, Pt, TiN, and a corresponding metal material, and an exposed sound source. Depending on the nature of the size may be designed in units of μm.

The acoustic chamber 220 is formed by wet etching of several micrometers to several tens of micrometers based on the silicon substrate 210, and in the etching, a solvent mixed etching solution is used to improve an etching rate and an etching surface state. And an insulating film of Si02 or Si3N4 for insulation between the silicon substrates, formation of the electrode plate, and blocking leakage current.

The acoustic chamber 220 has a protrusion 250 of an oxide film protruding in a hemispherical shape from the center of the bottom surface, the metal electrode plate 260 is formed on the upper side of the protrusion.

That is, the protrusion 250 is a thermal oxide film grown to 1 μm to 3 μm or more in the center of the acoustic chamber in order to adjust the gap between the diaphragm and the electrode plate. The protrusion 250 is manufactured in a hemispherical structure so that the acoustic chamber 220 can smoothly discharge the air flow due to the sound pressure generated by the vertical movement of the upper diaphragm 270. In addition, the lower electrode plate 260 is also a metal film having a thickness of several thousand to several μm, and may be formed of Ti, Au, Cu, Al, Pt, TiN, and other metal materials corresponding thereto.

The diaphragm 270 has a plurality of first contact terminals 271 protruding from the edge and formed integrally, and the electrode plate 260 has an integral second contact terminal 261 extending from the edge for power connection. It detects (drives) an external sound source (sound pressure).

The plurality of support zones 230 may be formed to be adjacent to the electrode plate at a lower side thereof.

Figure 3 (a) is a front view of the MEMS microphone projecting the upper vibration plate and the structure of the lower according to another embodiment of the present invention, each of Figures 3 (b) and (c) is a cut line A2-A2 A cross-sectional view taken along 'and B2-B2' is shown.

Referring to Figure 3 (a) to (c), the MEMS microphone 300 according to another embodiment of the present invention is a diaphragm 270 of the upper portion of the MEMS microphone 200 according to the embodiment ) Is configured by replacing the diaphragm 310 having a plurality of through holes 320.

Except for the diaphragm 310 having the plurality of through holes 320 is the same as the configuration of the MEMS microphone 200 according to an embodiment of the present invention, the overlapping portion is omitted below, Only the differences are explained.

The MEMS microphone 300 includes the diaphragm 310 having the through-hole 320 formed therein, so that the sacrificial layer 410 can be more smoothly removed from the integrated acoustic chamber 220.

The MEMS microphone 300 may have one of the plurality of through holes 320 formed at the center of the diaphragm and the other formed at the edge of the diaphragm. In this case, the plurality of support zones 230 may be formed to be adjacent to the electrode plate 260 at a lower side thereof. The position of the through-hole is only one embodiment, the position of the through-hole 320 formed in the diaphragm 270 is not limited to the embodiment, any one or a plurality of the diaphragm depending on the required or required performance It can be formed at the position of.

4 is a flowchart illustrating a method of manufacturing a MEMS microphone according to an embodiment of the present invention, and FIG. 5 is a process chart of forming a MEMS microphone according to the process of the manufacturing method of FIG. 4. FIG. 5 (a) illustrates a process of removing a nitride film at a position where a lower electrode plate is to be formed, and FIG. 5 (b) opens an ellipsoidal stepped structure at a position where the nitride film is removed in FIG. 5 (a). FIG. 5C illustrates a process of forming an oxide film, and FIG. 5C illustrates a process of forming a lower electrode plate and an integrated electrode contact part on the thermal oxide film of FIG. 5B. FIG. 5 (d) illustrates a process of forming a sacrificial layer to cover the interior of the acoustic chamber and a plurality of supports to form an upper diaphragm, and FIG. 5 (e) illustrates a sacrificial layer to form an upper diaphragm. This shows a process of removing the upper portion of the sacrificial layer such that the upper diaphragm and the plurality of supports are equally stepped by using a surface processing technique.

4 to 5, the MEMS microphone manufacturing method according to an embodiment of the present invention includes a) forming an acoustic chamber and a plurality of support zones on an upper surface of a substrate (S10); b) forming an electrode plate in the center of the bottom surface of the acoustic chamber (S30); c) forming a sacrificial layer on the upper surface of the substrate and the acoustic chamber (S40); d) forming a diaphragm supported by the support zone above the electrode plate after removing a portion of the upper side of the sacrificial layer (S50); And e) removing the sacrificial layer (S60).

In the a) step S10, a plurality of auxiliary supports are further formed between the plurality of supporting zones, an oxide film is formed on a surface of the substrate, and the patterned oxide film is etched to form the acoustic chamber and the plurality of substrates. A support zone and the plurality of auxiliary supports are formed, and a nitride film is formed on surfaces of the acoustic chamber, the plurality of support zones, and the plurality of auxiliary supports (S20).

In the step a) (S10), the plurality of support zones and the plurality of auxiliary supports are formed inside the acoustic chamber, and the heights of both supports are the same.

In step b), after removing the nitride film in the center of the acoustic chamber, a hemispherical oxide film 250 is formed, and then the electrode plate 260 is formed as a metal film on the hemispherical oxide film.

In the step S40, the sacrificial layers 410 and 420 may be formed to have the thickness of the plurality of support zones, the plurality of auxiliary supports, and the acoustic chambers having a thickness greater than 1 to 1.5 times the depth of the acoustic chamber 220. It is formed to cover.

In step d), the upper portion of the sacrificial layer is removed to expose the nitride films on the upper surfaces of the plurality of support zones and the plurality of auxiliary supports, and the sacrificial layer is at least poly-silicon-based. The isotropic etching gas containing the plasma is formed of a material which is easily etched.

In the step S10, the oxide film 211 in the range of several thousand micrometers to several micrometers is formed on the upper surface of the silicon substrate 210, and then the photoresist is spaced at regular intervals to form the acoustic chamber 220. After patterning and etching the oxide film 211, the silicon substrate 210 is wet etched to form an acoustic chamber 220, a plurality of support zones 230, and a plurality of auxiliary supports 203 having a depth of several μm. Here, the plurality of auxiliary supports 20 are formed to prevent sagging and sticking due to stress that may occur during driving of the diaphragms 270 and 310.

At this time, the surface of the acoustic chamber 220 is a solvent (wt% solvent) to maintain the roughness of the etched surface in the same state as the roughness of the existing substrate for the smooth flow of sound pressure generated by the vibration of the diaphragm (270,310) It is preferable to etch by the etching solution which mixed).

Thereafter, a nitride layer 221 is further formed to further protect the etched silicon surface, and the nitride layer is finally used as an etch stop layer when the sacrificial layer 210 is removed to secure an air gap of the acoustic chamber 220. It is also utilized, and also blocks the leakage current between the diaphragm and the electrode plate.

The nitride film 221 is removed after the photoresist patterning to form the hemispherical projecting oxide step 250 in the center of the etched acoustic chamber 220 in order to form the circular electrode plate 260 having a diameter of several μm.

When forming the oxide film step 250, the depth of the acoustic chamber 220 may be primarily set to form the closest gap between the upper metal diaphragms 270 and 310 and the lower metal electrode plate 260 to improve acoustic sensitivity. It requires a proper depth of the acoustic chamber 220 in the μm range, and can adjust the oxide film step 250 formed at the lower side of the lower electrode plate 260 to the second to form the closest air gap, thereby improving the excellent acoustical feeling.

The half-array oxide step 250 is formed of an oxide film, and in order to accurately secure the step difference of the lower electrode plate 260, the oxide step 250 is considered in consideration of a loss amount (about 45%) of the silicon substrate 210. It is preferable to set the growth thickness of the s). The thickness of the oxide step is also an important parameter for smoothly discharging the sound pressure due to the vibration of the diaphragm 270 and 310.

The electrode plate 260 is formed of a metal film after the formation of the oxide film step 250. The electrode plate 260 is formed through a photoresist process after sputtering a metal film having a thickness of several thousand micrometers to several micrometers formed of an insulating film. do. The electrode contact portion 261 for applying current in this process is integrated, and as a material thereof, Ti, Au, Cu, Al, Pt, TiN, and other equivalent materials can be applied. Electrode contacts can be further formed.

The oxide film step 250 can be seen that the sound pressure due to the vibration of the diaphragm (270,310) has a linear structure, by which the sound pressure vibrating by the sound can be smoothly discharged along the linear structure.

In order to form the diaphragm, sacrificial layers 410 and 420 are formed in the acoustic chamber 220, the support zone 230, and the auxiliary support 240. At this time, the material of the sacrificial layer is a polymer-based and oxide-based material is used to facilitate the subsequent removal process.

In addition, the surface processing technology (polishing, CMP) is applied in order to ensure that the steps of the plurality of support zones and the plurality of auxiliary supports are positioned at the same height, and at this time, the acoustic chamber 220 to ensure smooth processability of the same process. It is desirable to apply an additional sacrificial layer 702 in the range of about 1 to 1.5 times the step of

Roughness of the surface 411 of the sacrificial layer should be the same level as the existing surface of the substrate 210, because the bottom surface of the diaphragm (270, 310) is integrated with the sacrificial layer by the final result as the roughness is intact When maintained, the vibration type of the diaphragm may change, which may affect the securing of excellent acoustic sensitivity by changing the vibration variation.

Subsequently, the diaphragm is formed by photoresist patterning after forming a metal film by a metal sputtering technique, and the sacrificial layer exposed to the outside of the diaphragm is removed through isotropic etching. In this case, the diaphragm 310 may include a through hole 320 in the diaphragm to increase the etching rate, thereby inducing faster etching.

6 (a) and 6 (b) are microscopic front photographs of the MEMS microphone of FIG. 2 and microscopic front photographs with the upper diaphragm removed, respectively. A microscope front view photograph of a MEMS microphone of 3 and a microscope front view photograph of a state where an upper vibrating plate is removed, and FIG. 8 is a microscope of a vertical cross section in which a MEMS microphone of FIGS. 1 and 2 forms a sacrificial layer. It is a photograph.

As shown in FIGS. 6 (b) and 7 (b), it can be seen that double insulating films (SiO 2 oxide film and Si 3 N 4 nitride film) are formed on the plurality of support zones and the plurality of auxiliary supports. In addition, it can be seen that the silicon surface is formed by acoustic etching of several um by wet etching, and the plurality of supporting zones and the plurality of auxiliary supporting supports are formed in the form of pillars. In addition, the electrode plate has an integral electrode contact portion formed of a metal on a hemispherical SiO 2 oxide film having a thickness of several um at a lower step.

In the double insulating film (SiO 2 oxide film + Si 3 N 4 nitride film) shown in FIG. 8, it is seen that no gap is generated in the Si 3 N 4 nitride film because it is grown to a very thin thickness. The acoustic chamber includes a sacrificial layer, and when the sacrificial layer is removed after the upper diaphragm is formed based on the photograph, an acoustic chamber is formed based on the solid line of the photograph.

As described above, the MEMS microphones 200 and 300 according to the embodiments of the present invention merely play a functional role of the acoustic chamber 220 according to the structure and shape of the support for supporting the upper metal diaphragm 270 and 310. There is an excellent advantage in that the MEMS microphone can be manufactured by performing a semiconductor process only on the upper portion of the substrate.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. It will be possible. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 illustrates a cross-sectional view of a MEMS microphone according to the prior art.

2 is a front view and a cross-sectional view of a MEMS microphone according to an embodiment of the present invention.

3 is a front view and a cross-sectional view of a MEMS microphone according to another embodiment of the present invention.

4 is a flowchart illustrating a method of manufacturing a MEMS microphone according to an embodiment of the present invention.

FIG. 5 is a view illustrating a MEMS microphone according to the process of the manufacturing method of FIG. 4.

6 (a) and 6 (b) are microscopic front photographs of the MEMS microphone of FIG. 2 and a front micrograph of the upper diaphragm.

7 (a) and 7 (b) are microscopic front photographs of the MEMS microphone of FIG. 3 and the front diaphragm of the upper diaphragm.

FIG. 8 is a micrograph of a vertical cross section of a MEMS microphone of FIGS. 1 and 2 in which a sacrificial layer is formed.

Claims (26)

Board; An acoustic chamber formed on top of the substrate; A plurality of support zones formed inside the acoustic chamber; An electrode plate formed on the bottom surface of the acoustic chamber; A diaphragm supported by the plurality of supporting zones and formed above the electrode plate; And MEMS microphones, which are formed between the plurality of support zones and include a plurality of auxiliary supports that support the diaphragm. The method of claim 1, MEMS microphone, characterized in that the diaphragm is provided with a plurality of through holes. delete The method of claim 1, And the acoustic chamber, the plurality of supports and the plurality of auxiliary supports are integrally formed with the substrate by etching the substrate. 5. The method of claim 4, The MEMS microphone, characterized in that the substrate is made of a silicon material. 5. The method of claim 4, MEMS microphone, characterized in that the acoustic chamber, the plurality of support and the plurality of auxiliary support comprises a nitride film formed on the surface. The method of claim 6, MEMS microphone, characterized in that the plurality of support and the plurality of auxiliary support comprises an oxide film formed on the lower portion of the nitride film from the upper side. The method according to claim 1 or 2, The acoustic chamber further comprises a protrusion formed between the electrode plate and the bottom surface (MEMS) microphone. The method of claim 8, The protrusion is a MEMS microphone, characterized in that the oxide film formed to protrude in a hemispherical shape in the center of the bottom surface of the acoustic chamber. The method according to claim 1 or 2, The MEMS microphone includes a plurality of first contact terminals protruding from the edge and formed integrally with each other. The method according to claim 1 or 2, And said electrode plate has an integral second contact terminal extending from an edge thereof. 3. The method of claim 2, MEMS microphones, characterized in that the plurality of supporting zones are formed adjacent to the electrode plate on the lower side. 3. The method of claim 2, One of the plurality of through holes is formed in the center of the diaphragm, the other is a MEMS microphone, characterized in that formed on the edge of the diaphragm. The method according to claim 1 or 2, MEMS microphone, characterized in that the diaphragm and the electrode plate is a metal film formed of any one material of Ti, Au, Cu, Al, Pt and TiN. a) forming an acoustic chamber and a plurality of support zones on the substrate; b) forming an electrode plate in the center of the bottom surface of the acoustic chamber; c) forming a sacrificial layer on an upper surface of the substrate and on the acoustic chamber; d) forming a diaphragm supported by the support zone above the electrode plate after removing the upper portion of the sacrificial layer; And e) removing the sacrificial layer MEMS (MEMS) microphone manufacturing method comprising a. The method of claim 15, In step d), MEMS microphone manufacturing method characterized in that a plurality of through-holes are formed on the diaphragm. The method according to claim 15 or 16, Step a) is MEMS microphone manufacturing method, characterized in that further forming a plurality of auxiliary support between the plurality of support. The method of claim 17, Step a) is Forming an oxide film on the surface of the substrate; Forming the acoustic chamber, the plurality of support zones, and the plurality of auxiliary supports by etching after patterning the oxide film; And Forming a nitride film on surfaces of the acoustic chamber, the plurality of support zones, and the plurality of auxiliary supports; MEMS microphone manufacturing method comprising a. The method of claim 18, Step a) is The plurality of support and the plurality of auxiliary support is formed in the interior of the acoustic chamber, characterized in that the height of both supports are formed (MEMS) microphone, characterized in that. The method of claim 18, b) step, Removing the nitride film in the center of the acoustic chamber and forming a hemispherical oxide film; And Forming the electrode plate, which is a metal film, on the hemispherical oxide film MEMS (MEMS) microphone manufacturing method comprising a. The method of claim 15, The diaphragm and the electrode plate is a metal film formed by a metal sputtering technique, MEMS microphone manufacturing method characterized in that the material of any one of Ti, Au, Cu, Al, Pt and TiN. The method of claim 15, The diaphragm and the electrode plate is a MEMS microphone manufacturing method characterized in that to form an integral contact terminal for power supply at the edge. The method of claim 16, In step a), MEMS microphone manufacturing method, characterized in that the plurality of supporting zones are formed adjacent to the electrode plate on the lower side. The method of claim 18, In step c), And the sacrificial layer is formed to cover the plurality of support zones, the plurality of auxiliary supports, and the acoustic chamber with a thickness greater than 1 times and 1.5 times the depth of the acoustic chamber. . 24. The method of claim 23, In step d), And a portion of an upper side of the sacrificial layer is removed so that the nitride films on the upper surfaces of the plurality of support zones and the plurality of auxiliary support blocks are exposed. The method of claim 15, The sacrificial layer is a MEMS microphone manufacturing method, characterized in that the material is easily etched by an isotropic etching gas containing a poly-silicon-based plasma.

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