KR101201262B1 - Vibratile Membrane and Backchamber of A Capacitive Type MEMS Microphone and Method for Manufacturing the Same - Google Patents

Abstract

PURPOSE: A vibrating membrane and a back plate of a capacitance type microphone based on a MEMS(Micro Electro Mechanical System) and a method for manufacturing the same are provided to prevent oxidation due to external humidity by forming an insulating layer on the vibrating membrane and the back plate. CONSTITUTION: A first insulation layer is formed on the upper part of a substrate(101). A vibrating membrane(102) forms a second insulation layer on the top of a first metal layer. A sacrificial layer for an air gap is formed on the upper part of the vibrating membrane. An external surface of the sacrificial layer is patterned by a photolithography process. A third insulation layer is formed on the upper part of the patterned sacrificial layer. A second metal layer is formed on the upper part of the third insulation layer. An upper conductive line is formed on the patterned second metal layer. A fourth insulating layer is formed on the upper part of a second metal layer. A back plate is obtained by the photolithography process. A sound inlet hole and a vibration hole are formed.

Description

Vibration Membrane and Backchamber of A Capacitive Type MEMS Microphone and Method for Manufacturing the Same

The present invention relates to a capacitive microphone and a method of manufacturing the same, and more particularly, MEMS (Micro Electro) capable of preventing the adhesion of the vibrating membrane and the back plate during vibration of the vibrating membrane due to the inflow of sound waves, and controlling the stress of the vibrating membrane. Mechanical Systems) based on the vibration membrane and the back plate of the capacitive microphone and a method of manufacturing the same.

MEMS (Micro Electro Mechanical Systems) -based capacitive microphones have the principle of converting the capacitance change between the vibrating membrane and the backplate due to sound pressure into an electrical signal. As illustrated in FIG. 1, the vibration membrane and the back plate are made of a single material of a conductive electrode for converting an electrical signal and applying a bias.

1 is a cross-sectional view of a capacitive microphone based on MEMS (Micro Electro Mechanical Systems) according to the prior art. As shown, a typical Micro Electro Mechanical Systems (MEMS) based capacitive microphone includes a silicon substrate 101, a single vibrating membrane 102, and a conventional back plate 103.

The single vibrating membrane 102 is made of Siemens, FBR (Fluidized Bed Reactor), MG-SoG (Solar Grade Metallurgical Silicon), VLD (Vapor-to-Liquid Deposition) polysilicon ) Made of material. In addition, it is made of a metal film.

The single vibrating membrane 102 is manufactured by CVD (Chemical Vapor Deposition) method, and the doping of the conductive material by the ion implant (Ion implant) method to convert the change of capacitance due to the negative pressure into an electrical signal. The conventional back plate 103 is also made of a polysilicon material doped with a conductive material. In addition, the conventional back plate 103 can be applied to the bias using a metal thick film formed by the electroplating (Electro Plating) method.

Capacitive microphone based on MEMS (Micro Electro Mechanical Systems) consisting of a single vibrating membrane 102 and a conventional back plate 103 manufactured in this manner causes collapse of the vibrating membrane when excessive sound pressure is introduced from the outside. In addition, the vibration membrane and the back plate may be bonded due to the influence of electrostatic force that may occur in a device using a microphone such as a mobile phone. This reduces the sensitivity of the microphone and causes internal damage.

The present invention is to solve the above-described problems, to prevent the adhesion of the vibration membrane and the back plate generated when the vibration membrane is made of a single material, and to prevent oxidation of the vibration membrane and the back plate due to external temperature or humidity An object of the present invention is to provide a vibrating membrane and a back plate of a MEMS-based capacitive microphone.

Furthermore, the present invention provides a vibrating membrane and a back plate of a MEMS-based capacitive microphone that prevent breakage and collapse of a vibrating membrane caused by excessive sound pressure, static electricity or physical shock caused by external sound waves. The purpose.

In order to achieve the above object, a method of manufacturing a vibrating membrane and a back plate of a MEMS-based capacitive microphone according to an embodiment of the present invention includes preparing a substrate, forming a first insulating layer on the substrate, and Forming a first metal layer on the insulating layer, patterning and etching an outer surface of the first metal layer by a photolithography process, forming a lower conductive line on the patterned first metal layer, and Acquiring a vibrating membrane by forming a second insulating layer on the first metal layer, forming a sacrificial layer for an air gap on the vibrating membrane, and patterning the outer surface of the sacrificial layer by a photolithography process. Etching, forming a third insulating layer on top of the patterned sacrificial layer, patterning the photolithography process to form a plurality of sound wave inlet holes, Etching is a step, forming a second metal layer on top of the third insulating layer, patterning the upper part by a photolithography process to form the outer surface of the second metal layer and the plurality of sound wave inlet holes, and etching Etching, forming an upper conductive line on the patterned second metal layer, forming a fourth insulating layer on the second metal layer, and patterning the upper part by a photolithography process to form a plurality of sound wave inlet holes. And etching to obtain the back plate, removing the sacrificial layer to form an air gap and a plurality of sound wave inlet holes, and forming vibration holes in the substrate.

Furthermore, the vibrating membrane and the back plate of the MEMS-based capacitive microphone according to an embodiment of the present invention are formed on the substrate on which the vibration holes are formed and on the substrate, and a lower electrode between the first insulating layer and the second insulating layer. The first metal layer is formed on the vibration membrane vibrating according to the sound pressure of the external sound wave (Sound Wave), is formed on the upper part of the vibration membrane, has a height in the vertical direction for the release (Release) of the vibration membrane and the external sound wave (Sound Wave on the top) The second metal layer, which is an upper electrode, is formed between the air gap having a plurality of openings for inflow of the air gap and the third insulating layer and the fourth insulating layer formed on the air gap. It includes a back plate having a plurality of sound wave inlet holes formed by extending the opening of the gap (Air Gap).

As described above, the present invention forms the first and second insulating layers on the surface of the first metal layer of the vibration membrane corresponding to the lower electrode, and the third and fourth on the surface of the second metal layer of the back plate corresponding to the upper electrode. By forming the insulating layer, it is possible to prevent the adhesion between the vibrating membrane and the back plate in the air gap during the vibration of the vibrating membrane due to negative pressure.

Furthermore, by forming an insulating layer on the vibrating membrane and the back plate, it is possible to prevent oxidation caused by external humidity, and to form the insulating material and thickness forming the insulating layer differently according to circumstances. The sensitivity and reliability of the microphone can be improved.

1 is a cross-sectional view of a capacitive microphone based on MEMS (Micro Electro Mechanical Systems) according to the prior art.
2A to 2J illustrate a method of manufacturing a vibrating membrane and a back plate of a MEMS-based capacitive microphone according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

2A to 2J illustrate a method of manufacturing a vibrating membrane and a back plate of a MEMS-based capacitive microphone according to an exemplary embodiment of the present invention. As shown, the method of manufacturing a vibrating membrane and a back plate of a MEMS-based capacitive microphone according to the present invention includes preparing a substrate (s101), forming a first insulating layer on the substrate (s102), Forming a first metal layer on the first insulating layer, patterning and etching an outer surface of the first metal layer by a photolithography process (s103), and forming a lower conductive line on the patterned first metal layer. Forming a second insulating layer on the first metal layer to obtain a vibrating membrane (s104), forming a sacrificial layer for an air gap on the vibrating membrane, and photolithography the outer surface of the sacrificial layer. Patterning and etching by a photolithography process (s105), forming a third insulating layer on the patterned sacrificial layer, patterning the photolithography process to form a plurality of sound wave inlet holes,Etching (S106), forming a second metal layer on the third insulating layer, patterning the upper part by a photolithography process to form an outer surface of the second metal layer and a plurality of sound wave inlet holes, In etching (S107), an upper conductive line is formed on the patterned second metal layer, a fourth insulating layer is formed on the second metal layer, and the upper part is formed by photolithography to form a plurality of sound wave inlet holes. patterning and etching the photolithography process to obtain a back plate (s108), removing the sacrificial layer to form an air gap and a plurality of sound wave inlet holes (s109), and vibrating the substrate. Forming a hole (s110).

As illustrated in FIG. 2A, the preparing of the substrate (s101) is a substrate 301 which is basically usable for fabricating a semiconductor device or an integrated circuit (IC), and is mainly formed of Si. In addition, any one of a sapphire substrate, a SiC substrate, a GaN substrate, or a GaAs substrate may be used as the substrate. In addition, the substrate 301 has a high degree of flatness through the slide cutting of the single crystal silicon and uniform surface treatment. In general, the thickness is made of a disk shape of a few millimeters, a diameter of several centimeters, and used as a separate substrate by cutting after the inspection process.

As illustrated in FIG. 2B, in the forming of the first insulating layer on the substrate (S102), the chemical vapor deposition deposit (CVD) method may be performed on the substrate 301 prepared in step S101. The insulating layer 302a is formed. The thickness of the first insulating layer 302a may be formed to a thickness of several μm, and in the present invention, the thickness of the first insulating layer 302a is preferably less than 1 μm. The first insulating layer 302a may be made of various insulating materials. In addition to the CVD method, a spin coating method or a slit using an insulating material of a liquid type, such as polyimide, teflon, and the like, may be used. It can be implemented by coating (Slit Coating) method. The present invention is not limited thereto, and the first insulating layer formation 302a may be formed to a thickness of several μm.

As shown in FIG. 2C, forming a first metal layer on top of the first insulating layer, patterning and etching an outer surface of the first metal layer by a photolithography process ( S103 forms a first metal layer 302b for bias application on the upper surface of the first insulating layer 302a formed in step S102. The first metal layer 302b is formed on the entire surface of the first insulating layer 302a, and a portion of the outer surface is patterned by a photolithography process.

The patterned first metal layer 302b is etched by dry etching using a gas or wet etching using a metal etchant. The etched first metal layer 302b is formed in an inner region of the upper surface of the first insulating layer 302a and may include conductive lines in some regions. The present invention is not limited thereto, and the first metal layer 302b may be formed on the entire upper surface of the first insulating layer 302a. The first metal layer may be formed to a thickness of several μm, and in the present invention, it is preferable to form a thickness of less than 0.1 μm.

The first metal layer 302b is an electrode for bias application and is made of any one or more materials of conductive materials such as Ti, Cr, Al, Mo, Co, Ni, Ag, Pt, Au, La, In, or Se. . Indium tin oxide (ITO), tin antimony oxide (TAO), indium zinc oxide (IZO), zinc oxide (ZnO), cadmium tin oxide (CTO), carbon nanotubes (CNT) or nanometals (NM) It may include one or more.

The first metal layer 302b made of a conductive material is formed by any one of a thermal evaporator, an E-beam evaporator, or a sputter (RF or DC sputter). In addition, a mask may be used when forming the first metal layer for patterning.

As illustrated in FIG. 2D, in operation S103, a lower conductive line is formed on the patterned first metal layer, and a second insulating layer is formed on the first metal layer to acquire a vibrating membrane. A second insulating layer 302c is formed on the upper surface of the first metal layer 302b, which is a lower electrode formed at. In addition, a portion of the second insulating layer 302c is patterned by a photolithography process and etched by any one of dry etching or wet etching. By patterning and etching the second insulating layer 302c, a portion of the first metal layer 302b is exposed, and a conductive line is formed in the exposed region. The thickness of the second insulating layer 302c may be formed to a thickness of several μm, and in the present invention, the thickness of the second insulating layer 302c is preferably less than 1 μm.

The second insulating layer 302c may be made of various insulating materials, and may be implemented by spin coating or slit coating. The present invention is not limited thereto, and the second insulating layer may be formed to a thickness of several μm.

By performing steps s101 to s104, the vibration membrane 302 of the MEMS-based capacitive microphone can be obtained. Since the vibrating membrane 302c is formed between the first insulating layer 302a and the second insulating layer 302c, the first metal layer 302b for bias application is formed on the upper electrode when vibrating the vibrating membrane 302 due to negative pressure. It is not bonded with the back plate 304 including. Furthermore, since the first insulating layer 302a, the first metal layer 302b, and the second insulating layer 302c can be formed of various insulating materials and conductive materials, the sensitivity, tone, and electrical characteristics of the MEMS-based capacitive microphone Can be changed. In addition, it is possible to prevent internal oxidation due to moisture introduced from the outside can extend the life of the microphone.

As illustrated in FIG. 2E, a sacrificial layer for forming an air gap is formed on an upper portion of the vibrating membrane, and the outer surface of the sacrificial layer is patterned and etched by a photolithography process. Step s105 is performed from step s101 to step s104 to form a sacrificial layer 303a made of a metallic material on top of the obtained vibration membrane 302. In addition, the sacrificial layer 303a may be formed of an insulating material different from the insulating material forming the first insulating layer 302a and the second insulating layer 302c in addition to the metallic material. The sacrificial layer 303a may have a thickness of several μm, and in the present invention, the thickness of the sacrificial layer 303a may be in the range of 1 μm to 5 μm.

The sacrificial layer 303a has a height so as to form an air gap 303 for the release of the vibration membrane 302, and the outer surface of the sacrificial layer 303a is patterned by a photolithography process. It is etched by dry etching used or wet etching using organic, acid or alkali chemicals. The material used as the sacrificial layer used in the present invention is a metal, and besides the metal, polymer series such as PR, polyimide, Teflon, silicon nitride film formed by CVD, silicon oxide film and the like can be used. However, the material used as the 1/2/3 / 4th insulating layer and the 1 / 2th metal layer and materials that do not affect each other in the process are limited. The region of the etched sacrificial layer 303a is a region perpendicular to the region of the first metal layer 302b formed in step s103.

Patterning of the sacrificial layer 303a may use a mask, and may be formed by any one of thermal evaporator, E-beam evaporator, and sputter (RF or DC sputter) deposition. In addition, since the sacrificial layer 303a is removed after the back plate 304 is formed, an air gap 303 for releasing the vibrating membrane 302 is formed.

As shown in FIG. 2F, a third insulating layer is formed on the patterned sacrificial layer, and is patterned by a photolithography process to form a plurality of sound wave inlet holes, and etching. In operation s106, a third insulating layer 304a is formed on the upper surface of the sacrificial layer 303a formed in the operation s105. The upper portion of the third insulating layer 304a patterns a plurality of sound wave inflow holes 305 for inflow of sound wave or sound pressure by a photolithography process. After patterning, etching is performed by either wet etching or dry etching.

The third insulating layer 304a may have a thickness of several μm, and in the present invention, the thickness of the third insulating layer 304a may be less than 1 μm. In addition, an area of the plurality of sound wave inflow holes 305 patterned on the sacrificial layer 303a is formed to be several μm. The intervals of the patterned sound wave inlet holes 305 are variably determined, and the variable intervals are determined from the gaps of the plurality of sound wave inlet holes 305 patterned in the second metal layer 304b and the fourth insulating layer 304c. same.

In addition, the third insulating layer 304a is formed on the upper side of the second insulator 302c of the vibration membrane, which is a region other than the top of the sacrificial layer 303a. Therefore, the same area as the second insulator 302c is patterned and etched to form the conductive line formed in the vibrating film 302. The present invention is not limited thereto, and the third insulating layer 304a may be formed on the sacrificial layer 303a and the second insulating layer 302c without etching. The material forming the third insulating layer 304a and the forming method are the same as the material and forming method of the first insulating layer 302a and the second insulating layer 302c of the vibration membrane 302.

As shown in FIG. 2G, the second metal layer is formed on the third insulating layer, and the upper part is formed by a photolithography process to form an outer surface of the second metal layer and a plurality of sound wave inlet holes. Patterning and etching (s107) form a second metal layer 304b on the top of the third insulating layer 304a by the method of forming the second metal layer 304b performed in step s103. In addition, the second metal layer 304b is made of a conductive material forming the first metal layer 302b.

The second metal layer 304b is patterned to form a sound wave inlet hole 305 having a cross-sectional area and a height of several to several tens of micrometers thereon, and is etched by a wet etching method or a dry etching method. In addition, the thickness of the second metal layer 304b may be made of several μm, and the present invention is preferably made of less than 0.1 μm. In addition, the second metal layer 304b may be a photolithography process in which a region corresponding to the region where the third insulating layer 304a and the second insulating layer 302c are etched to form a conductive line of the vibrator 302. Pattern and etch. The present invention is not limited thereto, and the second metal layer 304b may be formed on the entire upper surface of the third insulating layer 304a and sealed between the third insulating layer 304a and the fourth insulating layer 304c. It is possible to form.

As shown in FIG. 2H, an upper conductive line is formed on the patterned second metal layer, a fourth insulating layer is formed on the second metal layer, and an upper portion is formed to form a plurality of sound wave inlet holes. The step S108 of patterning and etching the photolithography process to obtain the back plate is performed on the second metal layer 302c formed in step S107 of the third insulating layer 304a formed in step S106. The fourth insulating layer 304c is formed of the same or different insulating material as that of the insulating material. The fourth insulating layer 304c can be formed by the method of forming the third insulating layer 304a.

By patterning and etching some surfaces of the fourth insulating layer 304c, it is possible to form conductive lines of the first metal layer 302b corresponding to the lower electrode and to form conductive lines of the second metal layer 302b corresponding to the upper electrode. . In addition, patterning and etching are performed by a photolithography process to form the plurality of sound wave inflow holes 305. Accordingly, a plurality of sound wave inflow holes 305 penetrating through the third insulating layer 304a, the second metal layer 304b, and the fourth insulating layer 304c are formed in the etched back plate 304. A fourth insulating layer 304c is formed inside the sound wave inlet hole 305 formed in the back plate 304, and the fourth insulating layer 304c includes the third insulating layer 304a and the second metal layer 304b. It is formed on the surface of the sound wave inlet hole 305 formed in.

In addition, by etching the etched regions of the second insulating layer 302c and the third insulating layer 304a, the conductive line forming region of the first metal layer 302b serving as the lower electrode is exposed. The present invention is not limited to this, and the fourth insulating layer 304c can be formed on the surface of the second metal layer 304b and on some surfaces of the third insulating layer 304a. The fourth insulating layer 304c may have a thickness of several μm, and preferably, the fourth insulating layer 304c is less than 1 μm.

By performing steps S105 to S108, the back plate 304 of the MEMS-based capacitive microphone can be obtained. The conductive lines formed on the vibrating membrane 302 and the back plate 304 are for electrical signal conversion and bias application of external sound waves. In the present invention, thermal evaporator and electron beam evaporator are used. Or sputter (RF or DC sputter) can be formed by any one, and is made of various conductive materials. In addition, patterning and etching performed in the process of forming the vibrating membrane 302 and the back plate 304 may be performed by various patterning methods and various etching methods.

Furthermore, as described above, the first insulating layer 302a, the second insulating layer 302c, the third insulating layer 304a, and the fourth insulating layer 304c are formed on the surfaces of the vibrating membrane 302 and the back plate 304. ) To prevent adhesion between the back plate 304 and the oxidation of the vibrating membrane 302 and the back plate 304 due to external temperature or humidity. Can be. In addition, the vibration membrane 302 is formed of a metal layer and an insulating layer instead of a single material, thereby preventing breakage and collapse of the vibration membrane 302 caused by excessive sound pressure, static electricity or physical shock caused by external sound waves. can do.

As illustrated in FIG. 2I, in operation S109, the sacrificial layer is removed to form an air gap and a plurality of sound wave inlet holes. The etching of the sacrificial layer 303a formed in step S105 is performed by dry etching. Or etching by wet etching. Thus, an air gap 303 for releasing the vibrating membrane 302 and a plurality of sound wave inflow holes 305 through which sound pressure is introduced are formed. The fourth insulating layer 304c is formed up to the inside of the sound wave inlet hole 305 to prevent oxidation and breakage of the upper electrode of the back plate 304 from external temperature and humidity.

The air gap 303 is formed in a region corresponding to the first metal layer 302b, which is the lower electrode of the vibrating membrane 302, to prevent the vibrating membrane 302 and the back plate 304 from coalescing.

As illustrated in FIG. 2J, in the forming of the vibration hole in the substrate (S110), a region corresponding to the region of the first metal layer 302b of the vibration membrane 302 may be formed by a photolithography process. Patterned and etched by dry etching or wet etching. Thus, a vibration hole 306 for free vibration of the vibration membrane 302 is provided.

As described above with reference to FIGS. 2A through 2J, the vibrating membrane and the back plate of the MEMS-based capacitive microphone according to the exemplary embodiment of the present disclosure may be described with reference to FIG. 2J. As shown, the vibration membrane and the back plate of the MEMS-based capacitive microphone 300 according to the present invention are formed on the substrate 301 and the substrate 301 on which the vibration holes are formed, and the first insulating layer 302a. The first metal layer 302b, which is a lower electrode, is formed between the second insulating layer 302c and the upper surface of the vibrating membrane 302 and the vibrating membrane 302 which vibrate according to the sound pressure of the external sound wave. And an air gap 303 and an air gap having a plurality of openings for inflow of external sound waves thereon and having a space for a release of the vibration membrane 302. A second metal layer 304b, which is an upper electrode, is formed between the third insulating layer 304a and the fourth insulating layer 304c formed on the top of the 303, and the opening of the air gap 303 is formed. It includes a back plate 304 having a plurality of sound wave inlet hole 305 is formed extending.

In one embodiment, the vibrating membrane 302 is formed on an upper portion of the substrate 301 on which the vibration hole 306 is formed and on a lower portion of the back plate 304 on which the air gap 303 is formed. In the vibrating membrane 302, a first metal layer 302b, which is a lower electrode, is formed between the first insulating layer 302a and the second insulating layer 302c to apply electrical conversion and bias when the vibrating membrane 302 vibrates. . To this end, the vibrating membrane 302 may include a conductive line (not shown). The first metal layer 302b of the vibrating membrane 302 is formed in an area above the first insulating layer 302a so as to vertically correspond to an area of the vibrating hole 306 formed in the substrate 301, and a partial region of the vibrating membrane 302 is formed. It may be formed on the front of the).

In addition, the second insulating layer 302c of the vibrating membrane 302 may have a first metal layer 302b formed thereon to seal the first metal layer 302b, and in some regions, the first metal layer 302b may be exposed. It may be formed to.

In an embodiment, the air gap 303 is formed in a region vertically corresponding to the region of the vibration hole 306 of the substrate 301, and the region of the first metal layer 302b of the vibration membrane 302. It is formed in the area corresponding to the vertical. In addition, the air gap 303 includes a plurality of sound wave inlet holes 305 and a plurality of openings extending thereon. Since the upper opening of the air gap 303 is integrally connected with the sound wave inlet hole 305, it may be determined to have the same meaning as the sound wave only hole 305.

An air gap 303 is formed between the vibrating membrane 302 and the back plate 304, thereby preventing coalescence with the back plate 304 when the vibrating membrane 302 vibrates due to negative pressure, and thus vibrating membrane. The 302 is formed of a first insulating layer 302a, a first metal layer 302b, and a second insulating layer 302c instead of a single material to prevent the vibration membrane 302 from collapsing and oxidizing due to excessive negative pressure.

In one embodiment, the back plate 304 is formed on the air gap 303, and the second metal layer 304b, which is the upper electrode, is different from the third insulating layer 304a and the fourth insulating layer 304c. Is formed. In addition, a plurality of sound wave inlet holes 305 are formed in the upper portion of the back plate 304 to allow sound pressure due to external sound waves to flow into the vibrating membrane 302. The plurality of sound wave inflow holes 305 formed in the back plate 304 pass through the third insulating layer 304a, the second metal layer 304b, and the fourth insulating layer 304c, and the lower air gap 303 Suffer

Some surfaces of the back plate 304 are formed to expose the second metal layer 304b as the upper electrode, and some surfaces of the back plate 304 are exposed to the first metal layer 302b as the lower electrode. In addition, an electrical conversion and a bias are applied to a part of the back plate 304 when the vibration membrane 302 vibrates. To this end, the back plate 304 may include a conductive line (not shown).

The back plate 304 is composed of a third insulating layer 304a, a second metal layer 304b, and a fourth insulating layer 304c instead of a single material, and release of the vibrating membrane 302 between the vibrating membranes 302. By forming the air gap 303 for (Release), it is possible to prevent the coalescence with the vibration membrane 302 and internal damage. In addition, according to circumstances, the thickness of the vibrating membrane 302 and the thickness and height of the back plate 304 may be formed differently, thereby improving sensitivity and reliability of the MEMS-based capacitive microphone.

The terms used throughout the present specification are terms defined in consideration of functions in the embodiments of the present invention, and may be sufficiently modified according to the intention, custom, etc. of the user or the operator, and thus, the definitions of the terms are used throughout the present specification. It should be made based on the contents.

While the invention has been described with reference to the preferred embodiments, which are referred to by the accompanying drawings, it will be apparent that various modifications are possible without departing from the scope of the invention within the scope covered by the claims set forth below from this description. .

101: silicon substrate
102: single vibration membrane
103: conventional backplate
300: MEMS-based capacitive microphone
301: substrate
302a: first insulating layer
302b: first metal layer
302c: second insulating layer
302: vibrating membrane
303a: sacrificial layer
303: Air Gap
304a: third insulating layer
304b: second metal layer
304c: fourth insulating layer
304: backplate
305: sound wave inflow hole
306: vibration hole

Claims (18)

Preparing a substrate;
Forming a first insulating layer on the substrate;
Forming a first metal layer on the first insulating layer, patterning and etching an outer surface of the first metal layer by a photolithography process;
Forming a lower conductive line on the patterned first metal layer, and forming a second insulating layer on the first metal layer to obtain a vibration membrane;
Forming a sacrificial layer for an air gap on the vibrating membrane, and patterning and etching an outer surface of the sacrificial layer by a photolithography process;
Forming a third insulating layer on the patterned sacrificial layer, patterning by photolithography to form a plurality of sound wave inlet holes, and etching the etching layer;
Forming a second metal layer on the third insulating layer, patterning and etching an upper portion of the second metal layer by a photolithography process to form an outer surface of the second metal layer and a plurality of sound wave inlet holes;
An upper conductive line is formed on the patterned second metal layer, a fourth insulating layer is formed on the second metal layer, and the upper part is patterned by a photolithography process to form a plurality of sound wave inlet holes, Etching to obtain a backplate;
Removing the sacrificial layer to form an air gap and a plurality of sound wave inlet holes; and
Forming a vibration hole in the substrate
MEMS-based capacitive microphone vibrating membrane and back plate manufacturing method comprising a. The method of claim 1, wherein the forming of the first metal layer on the first insulating layer, patterning the outer surface of the first metal layer by a photolithography process, and etching the same include:
MEMS formed in any one of the entire upper region or the partial region of the first insulating layer, characterized in that the etching by any one of dry etching (Wet Etching) or wet etching (Wet Etching) method Method for manufacturing vibration membrane and back plate of capacitive microphone based. The method of claim 1, wherein forming a lower conductive line on the patterned first metal layer and forming a second insulating layer on the first metal layer to obtain a vibrating membrane include:
A portion of the second insulating layer is patterned by a photolithography process, and the bottom conductive line is formed by etching by dry etching or wet etching. Method for manufacturing a vibrating membrane and a back plate of a MEMS-based capacitive microphone, characterized in that. The method of claim 1, wherein forming a sacrificial layer for an air gap on the vibrating membrane, and patterning and etching the outer surface of the sacrificial layer by a photolithography process,
The method of claim 1, wherein the sacrificial layer is formed of an insulating material or a metallic material different from the material forming the first insulating layer and the second insulating layer. The method of claim 1, wherein the sacrificial layer,
Method for manufacturing a vibrating membrane and back plate of the MEMS-based capacitive microphone, characterized in that formed to a thickness of 1㎛ ~ 5㎛ to enable the formation of the air gap (Air gap) for the release of the vibration membrane (Release). The method of claim 1, wherein an upper conductive line is formed on the patterned second metal layer, a fourth insulating layer is formed on the second metal layer, and an upper portion of the patterned second metal layer is formed by photolithography. Patterning and etching to obtain a back plate by a photolithography process,
Patterning a portion of the fourth insulating layer by a photolithography process and etching the dry conductive layer by wet etching or wet etching to form the upper conductive line. Method for manufacturing a vibrating membrane and a back plate of a MEMS-based capacitive microphone, characterized in that. The method of claim 1, wherein removing the sacrificial layer to form an air gap and a plurality of sound wave inflow holes,
Vibrating membrane and backplate of a MEMS based capacitive microphone, characterized in that the sacrificial layer is etched by at least one of wet etching, dry etching or ashing. Manufacturing method. The method of claim 7, wherein the air gap (Air Gap),
Method for manufacturing a vibrating membrane and back plate of the MEMS-based capacitive microphone, characterized in that formed in a region perpendicular to the region of the first metal layer. The method of claim 1, wherein the forming of the vibration hole in the substrate,
Patterning is performed in a photolithography process in a region vertically corresponding to the region of the first metal layer, and etching is performed by at least one of wet etching, dry etching, and ashing. Method of manufacturing a vibrating membrane and back plate of a MEMS-based capacitive microphone, characterized in that. The method of claim 1, wherein the vibrating membrane and the backplate manufacturing method of the MEMS-based capacitive microphone are
The upper conductive line and the lower conductive line may be thermally evaporated, an E-beam evaporator, or a sputter (RF or DC sputter) for electrical signal conversion and bias application of external sound waves. Method for manufacturing a vibrating membrane and back plate of the MEMS-based capacitive microphone, characterized in that formed by the method of. A substrate on which vibration holes are formed;
A vibrating membrane formed on the substrate and having a first metal layer, which is a lower electrode, formed between the first insulating layer and the second insulating layer to vibrate according to the sound pressure of an external sound wave;
An air gap formed on an upper portion of the vibrating membrane and having a space in a vertical direction for releasing the vibrating membrane, and having a plurality of openings therein for inflow of the external sound wave;
A second metal layer, which is an upper electrode, is formed between the third insulating layer and the fourth insulating layer formed on the air gap, and the plurality of sound wave inflows are formed by extending the opening of the air gap. Back Plate with Holes
Vibration membrane and back plate of the MEMS-based capacitive microphone comprising a. A substrate on which vibration holes are formed;
A vibrating film formed on the substrate and having a first metal layer formed as a lower electrode having an upper portion of an outer surface exposed between the first insulating layer and the second insulating layer to vibrate according to a sound pressure of an external sound wave;
An air gap formed on an upper portion of the vibrating membrane and having a space in a vertical direction for releasing the vibrating membrane, and having a plurality of openings therein for inflow of the external sound wave;
A second metal layer is formed between the third insulating layer and the fourth insulating layer formed on the air gap, the second electrode being an upper part of which the upper surface is exposed, and the opening of the air gap is extended. Back plate having a plurality of sound wave inlet holes formed
Vibration membrane and back plate of the MEMS-based capacitive microphone comprising a. The method according to any one of claims 11 to 12, wherein the first metal layer,
The vibrating membrane and the back plate of the MEMS-based capacitive microphone, characterized in that formed in a region perpendicular to the vibration hole region of the substrate. The air gap according to any one of claims 11 to 12,
The vibrating membrane and the back plate of the MEMS-based capacitive microphone, characterized in that formed in a region perpendicular to the vibration hole region of the substrate. The sound wave inlet hole according to any one of claims 11 to 12,
A vibrating membrane and a back of the MEMS-based capacitive microphone, which pass through the third insulating layer, the second metal layer, and the fourth insulating layer of the back plate, and communicate with the lower air gap. plate. The vibration membrane according to any one of claims 11 to 12,
Vibration membrane and back plate of the MEMS-based capacitive microphone further comprises a conductive wire for applying a bias to the vibration membrane and the back plate. The method according to any one of claims 11 to 12, wherein the back plate,
Vibration membrane and back plate of the MEMS-based capacitive microphone further comprises a conductive wire for applying a bias to the vibration membrane and the back plate. The method of claim 12, wherein the vibration membrane and the back plate of the MEMS-based capacitive microphone,
An outer surface of the second insulation layer, an outer surface of the third insulation layer, and an outer surface of the fourth insulation layer are formed to expose the top surface of the first metal layer. plate.

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