WO2018110878A1 - Microphone having horizontal tensile structure and method for manufacturing microphone - Google Patents

Abstract

The present invention relates to a microphone having a horizontal tensile structure and a method for manufacturing the microphone, comprises a membrane comprising a driving electrode and a back plate comprising a fixed electrode, and the two electrodes are mechanically connected to a substrate. The method for manufacturing a microphone having a horizontal tensile structure according to the present invention improves a structure supporting the back plate and a structure supporting the membrane, and thus there are the effects of improving the quality of the processes of manufacturing the microphone and improving the performance of the microphone.

Description

Microphones having a horizontal tensile structure and methods for manufacturing the microphones

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microphone having a horizontal tensile structure and a method of manufacturing the microphone, and more particularly, to form a negative electrode on a membrane and a back plate arranged in parallel to face each other, and to generate negative pressure through capacitances charged in the electrodes. It relates to a microphone to be measured and a method of manufacturing the microphone.

A microphone is a type of sensor that converts sound into electrical signals. Microphones are developed and produced in a variety of structures and shapes depending on the application.

Since a microphone used in a mobile device needs to be made small, it is generally produced by a micro electro mechanical system (MEMS) process. In addition, in the case of the microphone for a mobile device, a structure mainly of the capacitive type is widely used.

Capacitive microphones largely include a membrane and a backplate. Electrodes are formed on the membrane and the backplate, respectively, and the membrane is formed in a structure capable of vibrating according to a change in negative pressure. The backplate is formed into a flat plate structure that faces parallel to the membrane.

In the case of microphones manufactured by the MEMS process, the membrane and the backplate having a very thin thickness are formed on the substrate, so the design of the structure supporting the membrane and the backplate to the substrate has a great influence on the production yield and the quality. In particular, as a result of the MEMS process such as deposition and etching, the back plate generates internal stresses that cause the back plate to bend. Such backplate internal stress causes stress to act on the support for supporting the backplate to the substrate. If the backplate support does not sufficiently overcome the internal stress of the backplate, the backplate will bend and affect the quality of the microphone. In addition, there is a problem that the microphone does not operate normally as the back plate support is broken due to internal stress of the back plate in the process of producing the microphone or the process of using the microphone.

The present invention has been made to solve the problems described above, it is possible to sufficiently overcome the internal stress that may occur in the back plate of the microphone manufactured by the MEMS process and to stably support the back plate so that the back plate is not bent It is an object of the present invention to provide a method capable of producing a microphone having a horizontally tensionable structure, and a microphone manufactured by the method.

In order to solve the problems described above, the present invention, the air gap is disposed between the membrane and the back plate, the sound is detected by using the change in capacitance between the first electrode formed on the membrane and the second electrode formed on the back plate A method of manufacturing a microphone, comprising: (a) forming a first sacrificial layer on an upper surface of a substrate; (b) etching the first sacrificial layer to surround the outer circumference of the region where the membrane is to be formed to form a membrane outer circumference that exposes the surface of the substrate; (c) forming a first silicon layer by laminating undoped polysilicon on an upper surface of the substrate exposed through the membrane outer peripheral portion and an upper surface of the first sacrificial layer, and forming a membrane by the undoped polysilicon on the outer peripheral portion of the membrane. Forming a first support; (d) doping a region of the first electrode to be conductive to form the first electrode in the first silicon layer; (e) etching the first silicon layer leaving a residual area comprising a region where the membrane is to be formed, a region corresponding to the membrane first support portion, and a membrane second support portion extending outside the membrane first support portion; (f) depositing a second sacrificial layer on the first silicon layer after performing step (e); (g) depositing undoped-polysilicon on the second sacrificial layer to form a second silicon layer; (h) doping the second silicon layer to form a conductive second electrode in the second silicon layer; (i) etching the second silicon layer doped in step (h) to form the second electrode; (j) forming a back plate outer periphery for exposing the membrane second support by etching the second sacrificial layer to surround the outer periphery of the region where the back plate is to be formed to form a back plate support for supporting the back plate; step; (k) forming a back plate layer by depositing nitride on the second sacrificial layer, the back plate outer periphery, and the second electrode, and forming the back plate support part on the membrane second support part by the back plate outer periphery filled with the nitride; Doing; (l) etching the backplate layer and the second electrode of the plurality of sound hole regions to form a plurality of sound holes in an area surrounded by the back plate support; (m) removing a portion of the substrate in the area surrounded by the membrane first support at the bottom of the membrane to form a cavity; And (n) removing the first sacrificial layer exposed through the cavity and removing the second sacrificial layer exposed through the sound hole.

In addition, the microphone of the present invention, the substrate; A membrane disposed on the substrate; A membrane first support portion supporting an outer circumference of the membrane with respect to the substrate; A membrane second support portion formed to extend with respect to the membrane outwardly of the membrane first support portion; A back plate disposed above the membrane; A back plate support portion formed on the membrane second support portion to support an outer circumference of the back plate with respect to the membrane second support portion; A second electrode formed on the back plate; And a first electrode formed on the membrane.

The horizontally tensioned microphone of the present invention and the method for manufacturing the microphone thereof provide a method for producing a microphone with a horizontally tensioned structure having an improved backplate support structure and a microphone thereby, thereby improving the process yield of the microphone and improving the quality of the microphone. Has the effect of improving.

1 to 15 are cross-sectional views illustrating a method of manufacturing a microphone having a horizontal tensile structure according to an embodiment of the present invention.

FIG. 16 is a cutaway perspective view of a microphone manufactured by the method for manufacturing a microphone having a horizontal tensile structure shown in FIGS. 1 to 15.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of a microphone manufacturing method of a horizontal tensile structure according to the present invention will be described in detail.

1 to 15 are cross-sectional views illustrating a method of manufacturing a microphone having a horizontal tensile structure according to an embodiment of the present invention.

The method for manufacturing a microphone having a horizontal tensile structure according to the present invention is for producing a microphone having a structure as shown in FIG. 15. The membrane first support part 220 and the membrane second support part 230 are formed on the substrate 100 to support the membrane 200. The membrane first support 220 is firmly fixed to the substrate by the membrane support fixture 503. The membrane 200 is formed with a membrane second support 230 which is formed to extend with respect to the membrane 200 to the outside of the membrane first support 220. The membrane second support part 230 is fixed to the substrate 100 by the structures of the first sacrificial layer 510 and the second sacrificial layer 520, and in such a state, the membrane second support part 230 is formed of a membrane. Support 200. The first electrode 201 is formed on the membrane 200. The membrane 200 is vibrated by the sound pressure transmitted from the outside. The back plate 300 is disposed above the membrane 200. The backplate 300 is supported relative to the membrane second support 230 by the backplate support 310. A plurality of sound holes 320 are formed in the back plate 300. External sound pressure is transmitted to the membrane 200 through the sound hole 320 of the back plate 300. The second electrode 301 is formed on the back plate 300. When the membrane 200 vibrates, the distance between the first electrode 201 and the second electrode 301 is changed, and as a result, the capacitance between the first electrode 201 and the second electrode 301 is changed. By using such a change in capacitance, a change in sound pressure may be converted into an electrical signal. Meanwhile, a portion of the substrate 100 is removed below the membrane 200 to form a cavity 101.

Hereinafter, a method of manufacturing a microphone having the structure as described above will be described.

First, as shown in FIG. 1, a first sacrificial layer is formed on the upper surface of the substrate (step (a)). The first sacrificial layer 510 is prepared by depositing an insulating layer oxide film on the silicon wafer substrate 100.

Next, as shown in FIG. 2, a portion of the first sacrificial layer 510 is etched to surround the outer circumference of the region where the membrane 200 is to be formed to form a membrane outer circumference 501 exposing the surface of the substrate (( b) step). The membrane outer peripheral part 501 is formed by removing the first sacrificial layer 510 at the position where the membrane first support part 220 supporting the membrane 200 is to be formed to expose the substrate 100. The membrane first support 220 is formed on the substrate 100 to form the membrane outer circumference 501 in order to support the membrane 200. In order to form the membrane first support portion 220 for supporting the membrane 200 to effectively vibrate, the membrane outer periphery 501 is formed in a circular or near circular shape along the circumferential direction.

When the membrane outer peripheral portion 501 is formed as described above, the membrane support groove 502 is also formed. The membrane support groove 502 is formed by etching the first sacrificial layer 510 so that the surface of the substrate is exposed along the inner diameter of the membrane outer circumference 501 to be disposed at a position spaced inwardly with respect to the membrane outer circumference 501. That is, the membrane support groove 502 is formed parallel to the membrane outer peripheral portion 501 along the inner circumference of the membrane outer peripheral portion 501.

In this state, as shown in FIG. 3, the undoped polysilicon is laminated on the upper surface of the substrate 100 and the upper surface of the first sacrificial layer 510 exposed through the membrane outer periphery 501 to form the first silicon layer ( 610 is formed and a membrane first support portion 220 is formed on the membrane outer peripheral portion 501 (step (c)). At this time, the undoped polysilicon is also laminated to the membrane support groove 502. As such, the undoped polysilicon is laminated to form a membrane support fixing part 503 made of the first sacrificial layer 510 between the membrane outer peripheral part 501 and the membrane support groove 502. The first silicon layer 610 constitutes the membrane 200, the membrane first support part 220, and the membrane support fixing part 503.

Next, as shown in FIG. 4, the region of the first electrode 201 is doped to form the first electrode 201 on the first silicon layer 610 (step (d)). In the present embodiment, the first silicon layer 610 is doped by ion implantation. As a result of the doping, the first silicon layer 610 at the position where the first electrode 201 is to be formed becomes conductive. As described above, when the region of the first electrode 201 is doped, the region of the electrode pad is also doped. The electrode pad is formed to be able to be connected to an external circuit by wire bonding in the future.

Next, as shown in FIG. 5, the remaining first silicon layer 610 is etched while leaving the remaining region of the first silicon layer 610, and thus, the membrane 200, the membrane first support part 220, and the membrane second support part ( 230 (step (e)). That is, the remaining regions of the first silicon layer 610 except for the regions (remaining regions) to be the membrane 200, the membrane first supporting portion 220, the membrane second supporting portion 230, and the electrode pad 401 are etched. To be removed. By this process, the structure constituting the membrane 200 is completed. The membrane 200 is disposed at a height apart from the substrate and the membrane first support 220 is connected along an edge thereof to support the membrane 200 with respect to the substrate 100. The membrane first support 220 supports the membrane 200 relative to the substrate 100 at the position of the membrane outer circumference 501. In addition, the membrane second support part 230, which is a structure extending in the horizontal direction from the membrane 200, is formed outside the membrane first support part 220. The membrane second support 230 supports the membrane 200 with respect to the substrate 100 in a state where the membrane second support 230 is fixed to the substrate 100 by the first sacrificial layer 510.

Accordingly, the membrane 200 and the membrane second support 230 are horizontally disposed on the same plane, and the membrane first support 220 and the membrane second support 230 move the membrane 200 to the substrate 100. Will be supported.

Next, as illustrated in FIG. 6, the second sacrificial layer 520 is stacked on the first silicon layer 610 (step (f)). The second sacrificial layer 520 constitutes an air gap 420 between the membrane 200 and the back plate 300. The second sacrificial layer 520 is formed by stacking oxide films.

Next, as shown in FIG. 7, the undoped polysilicon is laminated on the second sacrificial layer 520 to form the second silicon layer 620 (step (g)).

The second silicon layer 620 formed in step (g) is doped to have conductivity, thereby preparing to form the second electrode 301 (step (h)). Like the first silicon layer 610 described above, the second silicon layer 620 is formed by stacking undoped polysilicon to form the second electrode 301 and doped by ion implantation to make it conductive. .

In this state, as shown in FIG. 8, the second silicon at the position 331 at which the dimple 330 is to be formed to form the dimple 330 to prevent adhesion between the back plate 300 and the membrane 200. A portion of the layer 620 and the second sacrificial layer 520 are etched (step (o)). The dimple 330 is an insulating structure formed on the back plate 300 to protrude toward the first electrode 201. The membrane 200 vibrates greatly during the use of the microphone, thereby preventing the first electrode 201 from sticking to the second electrode 301.

Next, as shown in FIG. 9, the second silicon layer 620 doped in step (g) is etched to form a second electrode 301 (step (i)).

As described above, when the structure of the second electrode 301 is completed, the structure for supporting the second electrode 301 is provided to complete the back plate 300.

First, as shown in FIG. 10, to form a back plate support 310 that supports the back plate 300 with respect to the membrane second support 230, to surround the outer circumference of the region where the back plate 300 is to be formed. The second sacrificial layer 520 is etched to form two rows of back plate outer peripheral portions 311 exposing the surface of the membrane second support portion 230 (step (j)). Membrane second support 230 is etched and positioned below the second sacrificial layer 520 to surround the membrane 200 and backplate 300 at a position relatively outward than the membrane first support 220. To be exposed. As such, the back plate support part 310 capable of supporting the back plate 300 with respect to the membrane second support part 230 is etched by etching the second sacrificial layer 520 to the depth at which the membrane second support part 230 is exposed. The foundation will be formed.

In this state, as shown in FIG. 11, nitride is deposited to form a back plate layer 701 forming the back plate support 310 and the back plate 300 (step (k)). In this case, the dimple 330 is formed by depositing nitride in the region etched in step (o). In this way, the back plate 300 and the back plate support part 310 are formed of the back plate layer 701 by the nitride structure to insulate the second electrode 301 from the substrate 100 and the membrane 200. While having an advantage that can be effectively fixed and supported. In particular, the back plate 300 may be stably supported by the back plate support part 310 having a structure in which a second sacrificial layer (back plate support fixing part) is filled between the back plate outer peripheral parts 311 filled with nitride. There is an advantage. In addition, due to the structure of the back plate outer periphery 311 and the second sacrificial layer 520 disposed therebetween, which has an insulating property and excellent selectivity with respect to the sacrificial layer, the space between the back plate 300 and the membrane 200 is later formed. When performing the process of forming the air gap 420 by removing the second sacrificial layer 520 of the, the configuration outside the back plate support 310 has an advantage that can be stably preserved without being affected. That is, due to the structure of the back plate support 310 as described above, the reproducibility of the process of etching the second sacrificial layer 520 is improved and the overall quality of the microphone manufacturing process is improved.

In addition, in the above-described step (e), the membrane 200 and the membrane second support part 230 are configured to horizontally extend on the same plane, and the membrane first support part 220 and the membrane second support part 230 are formed in the membrane ( 200, the lower portion of the back plate support 310 formed above the membrane second support 230 in steps (g) and (h) is flat without a step. It is formed in the form. As such, the step is not formed in the back plate support part 310 formed on the membrane second support part 230, so that the back plate layer 701 is generated by the moment that may occur at the edge portion of the back plate layer 701. Can reduce sagging.

Next, a process of forming electrode pads 401 and 402 for connecting the first electrode 201 and the second electrode 301 with an external circuit will be described.

First, as shown in FIG. 12, a portion of the back plate layer 701 or the back plate layer 701 and the second sacrificial layer 520 is etched to form the first silicon in the region where the electrode pads 401 and 402 are to be formed, respectively. Exposing the layer 610 and the second silicon layer 620 is performed (step (p)). A portion of the back plate layer 701 and the second sacrificial layer 520 is etched to expose a portion of the first silicon layer 610 so as to form an electrode pad 401 connected to the first electrode 201. To prepare. In the case of the electrode pad 402 connected to the second electrode 301, only a portion of the back plate layer 701 is etched.

Next, as illustrated in FIG. 12, the metal layers for forming the electrode pads 401 and 402 are stacked and then etched to be electrically connected to the first electrode 201 and the second electrode 301. 402 is formed respectively (step (q)).

Next, a process of forming the sound hole 320 will be described with reference to FIG. 13. As illustrated in FIG. 13, the back plate layer 701 and the second electrode 301 are etched at a plurality of points within the region surrounded by the back plate support 310 to form the sound hole 320 ( (l) step). As described above, the external sound pressure is transmitted to the membrane 200 inside the back plate 300 through the sound hole 320.

After the acoustic hole 320 is formed in this manner, as shown in FIG. 14, a portion of the substrate 100 in a region surrounded by the membrane first support portions 220 below the membrane 200 is removed. 101) (step (m)). The cavity 101 formed by etching the rear surface of the substrate 100 serves as a back chamber of the microphone.

Next, as shown in FIG. 15, the first sacrificial layer 510 and the second sacrificial layer 520 are removed through an etching process to make the membrane 200 vibrate ((n) step. ). As the second sacrificial layer 520 is removed, an air gap 420 is formed between the first electrode 201 and the second electrode 301, and the dimple 330 penetrating the second electrode 301 is the first electrode. Exposed to protrude toward 201. Meanwhile, as described above, the back plate support 310 is formed by using nitride having a high selectivity with respect to the sacrificial layer to form a chamber surrounded by the back plate support 310, and the membrane 200 is disposed therein. It becomes the structure that becomes. Since the inner space of the chamber is surrounded by the back plate support part 310, an advantage of preventing other components from being etched in the process of removing the first sacrificial layer 510 and the second sacrificial layer 520 is prevented. have. Due to the configuration of the nitride backplate support 310, there is an advantage that can improve the process yield. In addition, due to the configuration of the back plate support part 310 formed on the membrane second support part 230, there is an advantage that the back plate 300 can be firmly supported without sagging. In particular, since the back plate support part 310 has a structure in which a second sacrificial layer is filled between the outer periphery of the back plate 311 formed in two rows, only the second sacrificial layer 520 of the air gap 420 is removed and the back The second sacrificial layer 520 outside the plate support 310 remains without being removed to serve to fix and support the back plate support 310 from the outside. Due to the configuration of the present embodiment as described above, the back plate 300 is prevented from being deformed or drooped and the durability is improved. In addition, in the present embodiment, there is no concern that impurities of the second electrode 301 may diffuse into the back plate layer 701 during the heat treatment process. For this reason, the method of manufacturing a microphone having a horizontal tensile structure according to the present invention has an advantage of improving yield and improving product quality.

Meanwhile, as described above, in step (b), the membrane support groove 502 is formed, and in step (c), the undoped-polysilicon is also laminated to the membrane support groove 502 so that the membrane outer peripheral portion 501 and the membrane support groove are formed. By constructing the membrane first support portion 220 in which the membrane support fixing portion 503 is formed between the 502, there is an advantage that the membrane 200 can be more stably supported with respect to the substrate 100. By constructing the membrane first support portion 220 in such a structure, there is an advantage in that the reproducibility of the process of removing the first sacrificial layer 510 is improved and the quality of the overall microphone manufacturing process can be improved.

As mentioned above, although the preferable example was demonstrated about the microphone manufacturing method of the horizontal tension structure which concerns on this invention, the scope of the present invention is not limited to the case demonstrated above.

For example, the case in which the dimple 330 is formed to prevent adhesion between the first electrode 201 and the second electrode 301 has been described as an example. However, in some cases, the dimple may not be configured. It is possible.

In addition, the structure of the membrane 200 and the back plate 300 may be variously modified.

In addition, although the back plate layer 701 is formed by depositing nitride, it is also possible to configure the back plate layer using another insulating material.

On the other hand, the microphone of the present invention has the same structure as the microphone manufactured by the microphone manufacturing method of the horizontally tensioned structure described above.

As described above, the back plate support part 310 having a two-row structure has a structure in which an insulating layer oxide film is disposed between nitride films. That is, the back plate support part 310 surrounds the outer circumference of the back plate 300 while the back plate support part 310 covers the insulating layer oxide film deposited on the membrane second support part 230 in a state in which two rows of nitride films are covered. It is formed to. Even if the second sacrificial layer 520 is removed and the air gap 420 is formed by the structure, the back plate 300 may be effectively prevented from being etched or damaged in other components around the back plate support 310. ) Can secure a structure that can support () stably.

In addition, as described above, the membrane support fixing part 503 formed of an oxide film is formed on the outer side of the membrane supporting groove 502 and the outer periphery of the membrane 200 is covered with the nitride support covering the membrane supporting fixing part 503. By constituting the membrane first support portion 220 in a supporting structure, the membrane first support portion 220 may have a structure capable of stably supporting the membrane 200. In particular, the structure of the membrane first support portion 220 may improve the durability of the microphone by dispersing or offsetting internal stresses that may be generated by the membrane 200 or the peripheral structure of the membrane first support portion 220. There is an advantage.

Claims (9)

1. An air gap is disposed between a membrane and a back plate, and a method of manufacturing a microphone for detecting sound by using a change in capacitance between a first electrode formed on the membrane and a second electrode formed on the back plate,

   (a) forming a first sacrificial layer on an upper surface of the substrate;

   (b) etching the first sacrificial layer to surround the outer circumference of the region where the membrane is to be formed to form a membrane outer circumference that exposes the surface of the substrate;

   (c) forming a first silicon layer by laminating undoped polysilicon on an upper surface of the substrate exposed through the membrane outer peripheral portion and an upper surface of the first sacrificial layer, and forming a membrane by the undoped polysilicon on the outer peripheral portion of the membrane. Forming a first support;

   (d) doping a region of the first electrode to be conductive to form the first electrode in the first silicon layer;

   (e) etching the first silicon layer leaving a residual area comprising a region where the membrane is to be formed, a region corresponding to the membrane first support portion, and a membrane second support portion extending outside the membrane first support portion;

   (f) depositing a second sacrificial layer on the first silicon layer after performing step (e);

   (g) depositing undoped-polysilicon on the second sacrificial layer to form a second silicon layer;

   (h) doping the second silicon layer to form a conductive second electrode in the second silicon layer;

   (i) etching the second silicon layer doped in step (h) to form the second electrode;

   (j) forming a back plate outer periphery for exposing the membrane second support by etching the second sacrificial layer to surround the outer periphery of the region where the back plate is to be formed to form a back plate support for supporting the back plate; step;

   (k) depositing nitride on the second sacrificial layer, the back plate outer periphery, and the second electrode to form a back plate layer, and the back plate support part by the nitride filled back plate outer periphery; Forming on the second support;

   (l) etching the backplate layer and the second electrode of the plurality of sound hole regions to form a plurality of sound holes in an area surrounded by the back plate support;

   (m) removing a portion of the substrate in the area surrounded by the membrane first support at the bottom of the membrane to form a cavity; And

   (n) removing the first sacrificial layer exposed through the cavity and removing the second sacrificial layer exposed through the acoustic hole; and a method of manufacturing a microphone having a horizontal tension structure.
2. The method of claim 1,

   In the step (j), at least two rows of the outer circumference of the back plate are formed,

   In the step (k), the back plate support part having a structure in which the second sacrificial layer is disposed is formed between the nitride-filled back plate outer periphery, wherein the microphone has a horizontal tensile structure.
3. The method of claim 1,

   When the step (b) is performed, the first sacrificial layer is etched so that the surface of the substrate is exposed along the inner diameter of the membrane outer circumference to be disposed at a position spaced inwardly with respect to the membrane outer circumference to form a membrane support groove together. and,

   When the step (c) is performed, the undoped polysilicon is also laminated to the membrane support groove so that a membrane support fixing part formed of the first sacrificial layer is formed between the outer periphery of the membrane and the membrane support groove.

   When the first silicon layer is etched in the step (e), the membrane support fixing part remains inside the membrane first support part and is formed to fix the membrane first support part to the substrate. Microphone manufacturing method.
4. The method of claim 2,

   When the step (b) is performed, the first sacrificial layer is etched so that the surface of the substrate is exposed along the inner diameter of the membrane outer circumference to be disposed at a position spaced inwardly with respect to the membrane outer circumference to form a membrane support groove together. and,

   When the step (c) is performed, the undoped polysilicon is also laminated to the membrane support groove so that a membrane support fixing part formed of the first sacrificial layer is formed between the outer periphery of the membrane and the membrane support groove.

   When the first silicon layer is etched in the step (e), the membrane support fixing part remains inside the membrane first support part and is formed to fix the membrane first support part to the substrate. Microphone manufacturing method.
5. The method of claim 1,

   (p) a region in which electrode pads are to be formed by etching the backplate layer or the backplate layer and the second sacrificial layer by etching the nitride in the step (k) to form a backplate layer. Exposing the first silicon layer and the second silicon layer of; And

   (q) stacking a metal layer for forming the electrode pad to form an electrode pad electrically connected to the first electrode and the second electrode; and a method of manufacturing a microphone having a horizontal tensile structure.
6. The method of claim 2,

   (p) a region in which electrode pads are to be formed by etching the backplate layer or the backplate layer and the second sacrificial layer by etching the nitride in the step (k) to form a backplate layer. Exposing the first silicon layer and the second silicon layer of; And

   (q) stacking a metal layer for forming the electrode pad to form an electrode pad electrically connected to the first electrode and the second electrode; and a method of manufacturing a microphone having a horizontal tensile structure.
7. Board;

   A membrane disposed on the substrate;

   A membrane first support portion supporting an outer circumference of the membrane with respect to the substrate;

   A membrane second support portion formed to extend with respect to the membrane outwardly of the membrane first support portion;

   A back plate disposed above the membrane;

   A back plate support portion formed on the membrane second support portion to support an outer circumference of the back plate with respect to the membrane second support portion;

   A second electrode formed on the back plate; And

   And a first electrode formed on the membrane.
8. The method of claim 7, wherein

   And the back plate support part is formed of a structure in which an oxide film is disposed between at least two rows of the nitride film surrounding the outer circumference of the back plate and the nitride film.
9. The method of claim 7, wherein

   The membrane first support portion, nitride supporting the membrane support fixing portion of the oxide film material deposited on the upper surface of the substrate along the outer periphery of the membrane and the membrane support fixing portion to the substrate in a state covering the substrate Microphone, characterized in that consisting of a membrane.

Images