KR20240027404A - Mems microphone and method of manufacturing the same - Google Patents

Abstract

A MEMS microphone and its manufacturing method are disclosed. The MEMS microphone includes a diaphragm disposed on an upper portion of a substrate, a first anchor disposed on the substrate for fixing the diaphragm to the substrate, and a back plate disposed on an upper portion of the diaphragm. 1 The anchor has a plurality of vents connected to the air gap between the diaphragm and the back plate.

Description

MEMS microphone and method of manufacturing the same {MEMS MICROPHONE AND METHOD OF MANUFACTURING THE SAME}

Embodiments of the present invention relate to a Micro Electro Mechanical Systems (MEMS) microphone and a method of manufacturing the same. More specifically, it relates to a MEMS microphone including a diaphragm and a back plate formed using semiconductor processing technology and a method of manufacturing the same.

In general, MEMS microphones can be manufactured using semiconductor processing technology, and can output capacitance changes caused by changes in the gap between the diaphragm and the back plate as an electrical signal.

For example, the MEMS microphone may include a substrate having a cavity, a diaphragm disposed on an upper portion of the cavity, and a back plate disposed on an upper portion of the diaphragm. In this case, the diaphragm may include a first electrode layer, and the back plate may include a second electrode layer corresponding to the first electrode layer. Accordingly, the first electrode layer and the second electrode layer may be separated by vibration of the diaphragm. The capacitance between can change.

Additionally, the MEMS microphone may include a plurality of vents penetrating the diaphragm and a plurality of air holes penetrating the back plate. Accordingly, a flow of air may be generated through the vents of the diaphragm and the air holes of the back plate. However, the diaphragm may be contaminated by the air flow, which may cause a problem in which the sensitivity of the MEMS microphone is reduced.

The purpose of embodiments of the present invention is to provide a MEMS microphone that can prevent contamination of the diaphragm and a method of manufacturing the same.

A MEMS microphone according to an aspect of the present invention for achieving the above object includes a diaphragm disposed on an upper portion of a substrate, a first anchor disposed on the substrate and for fixing the diaphragm to the substrate, and the diaphragm of the diaphragm. It may include a back plate disposed on the top, and in particular, the first anchor may have a plurality of ventilation holes connected to the air gap between the diaphragm and the back plate.

According to some embodiments of the present invention, the first anchor may include a plurality of support patterns connected to edge portions of the diaphragm, and the plurality of vents may be defined by the plurality of support patterns. there is.

According to some embodiments of the present invention, the first anchor may further include a ring-shaped bottom portion disposed on the substrate to surround the plurality of support patterns.

According to some embodiments of the present invention, the substrate may have a cavity penetrating the substrate to correspond to the diaphragm, and the first anchor may have a ring shape surrounding the diaphragm and the cavity.

According to some embodiments of the present invention, the first anchor includes an inner wall portion configured to surround the diaphragm and the cavity, an outer wall portion configured to surround the inner wall portion, and a space between the inner wall portion and the outer wall portion. may include a bottom portion disposed on the substrate. In this case, the diaphragm may be connected to the upper part of the inner wall, and the plurality of vents may be formed penetrating the inner wall.

According to some embodiments of the present invention, the back plate may include a second electrode layer disposed to correspond to the diaphragm, and a support layer disposed on the second electrode layer and supporting the second electrode layer, The second electrode layer may be attached to the lower surface of the support layer.

According to some embodiments of the present invention, the diaphragm includes a first electrode layer corresponding to the second electrode layer, and the second electrode layer and the first electrode layer may have the same size.

According to some embodiments of the present invention, the MEMS microphone is disposed on the substrate and may further include a second anchor for fixing the support layer to the substrate. In this case, the first anchor may have a ring shape surrounding the diaphragm, and the second anchor may have a ring shape surrounding the first anchor.

According to some embodiments of the present invention, the MEMS microphone includes a first insulating layer disposed on the substrate to surround the second anchor, and a first insulating layer disposed on the first insulating layer to surround the second anchor. A second insulating layer, a first electrode pad disposed on the first insulating layer and electrically connected to the first electrode layer, and a second electrode pad disposed on the second insulating layer and electrically connected to the second electrode layer. It may further include, and an edge portion of the support layer may be disposed on the second insulating layer.

According to some embodiments of the present invention, the MEMS microphone includes a first bonding pad connected to the first electrode pad through an edge of the support layer and the second insulating layer, and a first bonding pad connected to the first electrode pad through an edge of the support layer. It may further include a second bonding pad connected to the second electrode pad.

According to some embodiments of the present invention, the back plate includes a plurality of protrusions that penetrate the second electrode layer and protrude from the support layer toward the diaphragm to prevent the second electrode layer and the first electrode layer from contacting each other. It may further include protrusions.

According to some embodiments of the present invention, the back plate may have a plurality of air holes connected to the air gap.

A MEMS microphone according to another aspect of the present invention for achieving the above object includes a substrate having a cavity, a diaphragm disposed on top of the substrate to correspond to the cavity and including a first electrode layer, and the cavity and the diaphragm. a back plate that has a surrounding ring shape and is disposed on the substrate and includes a first anchor for fixing the diaphragm to the substrate; a back plate disposed on an upper portion of the diaphragm and including a second electrode layer corresponding to the first electrode layer; It may have a ring shape surrounding the first anchor, be disposed on the substrate, and include a second anchor for fixing the back plate to the substrate. In particular, the back plate may have a plurality of air holes connected to the air gap between the diaphragm and the back plate, and the first anchor may have a plurality of vents for connecting the cavity and the air gap. there is.

According to some embodiments of the present invention, the first anchor has an inner wall portion including a plurality of support patterns connected to edge portions of the diaphragm, and a ring shape disposed on the substrate to surround the inner wall portion. It may include a bottom portion and a ring-shaped outer wall portion disposed on the substrate to surround the bottom portion. In this case, the plurality of vents may be defined by the plurality of support patterns.

A MEMS microphone manufacturing method according to another aspect of the present invention for achieving the above object includes forming a first insulating layer on a substrate, and patterning the first insulating layer to form a ring shape to partially expose the substrate. forming a first anchor channel, forming a diaphragm on the first insulating layer and a first anchor in the first anchor channel for fixing the diaphragm to the substrate, and forming the first anchor forming a plurality of vents by partially removing the vents, forming a second insulating layer on the first insulating layer, the diaphragm, and the first anchor, and forming a back plate on the second insulating layer. forming a cavity penetrating the substrate to correspond to the diaphragm, a portion of the first insulating layer formed within the first anchor, and a portion of the second insulating layer formed between the diaphragm and the back plate. It may include a step of removing . In particular, the cavity may be connected to an air gap between the diaphragm and the back plate through the plurality of vents.

According to some embodiments of the present invention, the first anchor includes an inner wall portion formed on a first inner surface of the first anchor channel adjacent to the diaphragm, and the first anchor facing the first inner surface. an outer wall formed on a second inner surface of the anchor channel, and a bottom formed on the substrate between the inner wall and the outer wall, wherein the plurality of vents are formed by partially removing the inner wall. You can.

According to some embodiments of the invention, forming the diaphragm and the first anchor includes forming a first silicon layer on inner surfaces of the first insulating layer and the first anchor channel; It may include performing an ion implantation process to form a portion of the first silicon layer as a first electrode layer, and patterning the first silicon layer to obtain the diaphragm and the first anchor. In this case, the diaphragm includes the first electrode layer, and a portion of the first silicon layer formed in the first anchor channel may be used as the first anchor.

According to some embodiments of the present invention, forming the back plate includes forming a second electrode layer corresponding to the first electrode layer on the second insulating layer, the second insulating layer and the first electrode layer. It may include forming a support layer on the two electrode layers to support the second electrode layer.

According to some embodiments of the present invention, the method of manufacturing the MEMS microphone includes patterning the second insulating layer and the first insulating layer to partially expose the substrate and forming a second anchor in the form of a ring surrounding the first anchor. The step of forming a channel may be further included. In this case, a portion of the support layer formed on the inner surfaces of the second anchor channel may be used as a second anchor for fixing the back plate on the substrate.

According to some embodiments of the present invention, the method of manufacturing the MEMS microphone may further include forming a plurality of air holes penetrating the back plate. In this case, a portion of the second insulating layer may be removed by an etchant supplied through the plurality of ventilation holes and the plurality of air holes.

According to the embodiments of the present invention as described above, the flow of air passing through the MEMS microphone may be achieved through the plurality of vents and the air holes. In particular, the air flow can pass through the plurality of vents formed through the first anchor, and thus contamination of the diaphragm by the air flow can be greatly reduced compared to the prior art. As a result, the sensitivity of the MEMS microphone can be greatly improved compared to the prior art.

Figure 1 is a schematic plan view for explaining a MEMS microphone according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view illustrating the MEMS microphone shown in FIG. 1.
Figure 3 is a schematic enlarged perspective view for explaining the ventilation hole shown in Figure 2.
FIG. 4 is a schematic enlarged cross-sectional view illustrating the flow of air through the vent shown in FIG. 2.
Figures 5 to 17 are schematic cross-sectional views for explaining the manufacturing method of the MEMS microphone shown in Figures 1 and 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention does not have to be configured as limited to the embodiments described below and may be embodied in various other forms. The following examples are not provided to fully complete the present invention, but rather are provided to fully convey the scope of the present invention to those skilled in the art.

In embodiments of the present invention, when one element is described as being disposed or connected to another element, the element may be directly disposed or connected to the other element, and other elements may be interposed between them. It could be. Alternatively, if one element is described as being placed directly on or connected to another element, there cannot be another element between them. The terms first, second, third, etc. may be used to describe various items such as various elements, compositions, regions, layers and/or parts, but the items are not limited by these terms. won't

Technical terms used in the embodiments of the present invention are merely used for the purpose of describing specific embodiments and are not intended to limit the present invention. Additionally, unless otherwise limited, all terms, including technical and scientific terms, have the same meaning that can be understood by a person skilled in the art. The above terms, as defined in common dictionaries, will be construed to have meanings consistent with their meanings in the context of the relevant art and description of the invention, and unless explicitly defined, ideally or excessively by superficial intuition. It will not be interpreted.

Embodiments of the invention are described with reference to schematic illustrations of ideal embodiments of the invention. Accordingly, changes from the shapes of the illustrations, for example changes in manufacturing methods and/or tolerances, are fully to be expected. Accordingly, the embodiments of the present invention are not intended to be described as limited to the specific shapes of the regions illustrated but are intended to include deviations in the shapes, and the elements depicted in the drawings are entirely schematic and represent their shapes. is not intended to describe the exact shape of the elements nor is it intended to limit the scope of the present invention.

Figure 1 is a schematic plan view for explaining a MEMS microphone according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view for explaining the MEMS microphone shown in FIG. 1, and FIG. 3 is a schematic enlarged perspective view for explaining the vent shown in FIG. 2. FIG. 4 is a schematic enlarged cross-sectional view illustrating the flow of air through the vent shown in FIG. 2.

1 to 4, the MEMS microphone 100 according to an embodiment of the present invention includes a substrate 102, a diaphragm 130 disposed on an upper part of the substrate 102, and the substrate 102. ) and may include a first anchor 140 for fixing the diaphragm 130 to the substrate 102 and a back plate 170 disposed on the diaphragm 130. In particular, the first anchor 140 may be provided with a plurality of vents 143 connected to the air gap AG between the diaphragm 130 and the back plate 170. Specifically, as shown in FIG. 3, the first anchor 140 may include a plurality of support patterns 144 connected to edge portions of the diaphragm 130, and in this case, the plurality of support patterns 144 Ventilation holes 143 may be defined by the plurality of support patterns 144 .

A silicon wafer may be used as the substrate 102, and the MEMS microphone 100 may be provided with a cavity 104 penetrating the substrate 102. In this case, the first anchor 140 may have a ring shape surrounding the cavity 104 and the diaphragm 130. Specifically, the support patterns 144 may be disposed on the substrate 102 to surround the cavity 104, and the vibration plate 130 may be connected to the upper part of the support patterns 144. You can. That is, the diaphragm 130 may be disposed on an upper portion of the cavity 104 to correspond to the cavity 104 . In this case, the support patterns 144 may function as elastic members that elastically support the diaphragm 130, and thus the structural stability of the diaphragm 130 will be greatly improved compared to the prior art. You can.

For example, the diaphragm 130 may have a disk shape, and the first anchor 140 may have a circular ring shape surrounding the cavity 104 and the diaphragm 130. The first anchor 140 has an inner wall portion 142 disposed on the substrate 102 to surround the cavity 104 and the diaphragm 130, and the substrate (142) to surround the inner wall portion 142. It may include a bottom portion 148 disposed on 102) and an outer wall portion 146 disposed on the substrate 102 to surround the bottom portion 148. Specifically, the inner wall 142 may include the support patterns 144, and the outer wall 146 may have a circular ring shape surrounding the inner wall 142. In addition, the bottom portion 148 may be disposed on the substrate 102 between the inner wall portion 142 and the outer wall portion 146 and may have a circular ring shape. In this case, the plurality of vents 143 may be formed penetrating the inner wall 142 and may be defined by the support patterns 144 .

The diaphragm 130 may include a disk-shaped first electrode layer 132 and an edge portion 134 surrounding the first electrode layer 132, and the first anchor 140 is of the diaphragm 130. It may be connected to the edge portion 134. For example, the first electrode layer 132 may be made of polysilicon doped with impurities, and the edge portion 134 of the diaphragm 130 may be made of undoped polysilicon. In this case, the first anchor 140 may be made of the same material as the edge portion 134 of the diaphragm 130. As another example, the diaphragm 130 may include a disk-shaped first electrode layer 132, and the first anchor 140 may be connected to an edge of the first electrode layer 132. In this case, the first electrode layer 132 may be made of polysilicon doped with impurities, and the first anchor 140 may be made of undoped polysilicon.

The back plate 170 includes a second electrode layer 172 disposed on the top of the diaphragm 130 to correspond to the diaphragm 130, and a second electrode layer 172 disposed on the second electrode layer 172. ) may include a support layer 182 to support the. For example, the second electrode layer 172 may have a disk shape and may be arranged to face the first electrode layer 132. In particular, the second electrode layer 172 may have the same size as the first electrode layer 132 and may be attached to the lower surface of the support layer 182. Additionally, for example, the second electrode layer 172 may be made of polysilicon doped with impurities, and the support layer 182 may be made of silicon nitride.

The MEMS microphone 100 may include a second anchor 188 for fixing the back plate 170 on the substrate 102. The second anchor 188 may be disposed on the substrate 102 and may fix the support layer 182 on the substrate 102. For example, the second anchor 188 may have a ring shape surrounding the first anchor 140. Specifically, the second anchor 188 may have a circular ring shape surrounding the first anchor 140 and a channel-shaped cross section. Also, for example, the second anchor 188 may be made of the same material as the support layer 182.

In addition, the MEMS microphone 100 includes a first insulating layer 110 formed on the substrate to surround the second anchor 188, and a first insulating layer (110) formed on the substrate to surround the second anchor 188. It may include a second insulating layer 150 formed on 110). A first electrode pad 136 connected to the first electrode layer 132 may be formed on the first insulating layer 110, and connected to the second electrode layer 172 on the second insulating layer 150. A second electrode pad 174 may be formed. In this case, the edge portion of the support layer 182 may be formed on the second insulating layer 150.

For example, the first electrode pad 136 may be connected to the first electrode layer 132 through a first connection pattern 138 (see FIG. 1), and the second electrode pad 174 may be connected to the second connection pattern 138. It may be connected to the second electrode layer 172 through a pattern 176 (see FIG. 1). Additionally, the first electrode pad 136 and the first connection pattern 138 may be made of the same material as the first electrode layer 132, and the second electrode pad 174 and the second connection pattern ( 176) may be made of the same material as the second electrode layer 172. For example, the first electrode pad 136 and the first connection pattern 138 and the second electrode pad 174 and the second connection pattern 176 may be made of polysilicon doped with impurities.

The MEMS microphone 100 includes a first bonding pad 194 electrically connected to the first electrode pad 136, and a second bonding pad 196 electrically connected to the second electrode pad 174. may include. For example, the first bonding pad 194 may be formed on the edge of the support layer 182 and penetrate through the edge of the support layer 182 and the second insulating layer 150 to form the first bonding pad 194. It may be connected to the electrode pad 136. The second bonding pad 196 may be formed on an edge of the support layer 182 and may be connected to the second electrode pad 174 through the edge of the support layer 182.

The back plate 170 penetrates the second electrode layer 172 to prevent the second electrode layer 172 and the first electrode layer 132 from contacting each other, and separates the support layer 182 from the diaphragm ( It may include a plurality of protrusions 186 protruding toward 130. Additionally, the back plate 170 may have a plurality of air holes 198 connected to the air gap AG.

According to one embodiment of the present invention, the flow of air passing through the MEMS microphone 100 may be achieved through the plurality of vents 143 and the air holes 198. In particular, as shown in FIG. 4, the air flow can pass through the plurality of vents 143 formed through the first anchor 140, and accordingly, compared to the prior art, the air flow can pass through. Contamination of the diaphragm 130 can be greatly reduced. Additionally, the elastic modulus of the diaphragm 130 can be adjusted by adjusting the size and number of the vents 143. As a result, the sensitivity of the MEMS microphone 100 can be greatly improved compared to the prior art.

Figures 5 to 17 are schematic cross-sectional views for explaining the manufacturing method of the MEMS microphone shown in Figures 1 and 2.

Referring to FIG. 5 , the first insulating layer 110 may be formed on the substrate 102. For example, a silicon wafer may be used as the substrate 102. The first insulating layer 110 may include silicon oxide and may be formed conformally, that is, to have a substantially uniform thickness, through a chemical vapor deposition process. Next, the first insulating layer 110 may be patterned to form a first anchor channel 112 in the shape of a circular ring. For example, after forming a photoresist pattern exposing the area where the first anchor channel 112 will be formed on the first insulating layer 110, an etching process is performed using the photoresist pattern as an etch mask. By doing so, the first anchor channel 112 exposing a portion of the upper surface of the substrate 102 can be formed.

Referring to FIG. 6, the first silicon layer 120 may be formed conformally on the first insulating layer 110 to have a substantially uniform thickness. For example, the first silicon layer 120 may be a polysilicon layer formed through a chemical vapor deposition process. In particular, a portion of the first silicon layer 120 formed in the first anchor channel 112 serves as a first anchor ( 140; see FIG. 8).

Referring to FIG. 7 , a portion of the first silicon layer 120 may be formed into a conductive first electrode layer 132 by performing an ion implantation process. In addition, the first electrode pad 136 and the first connection pattern 138 (see FIG. 1) for connecting the first electrode layer 132 and the first electrode pad 136 are formed by the ion implantation process. 1 may be formed in the silicon layer 120. For example, the first electrode layer 132 may be formed to have a disk shape, and the first electrode pad 136 may be formed to be spaced apart from the first electrode layer 132.

Referring to FIG. 8, by patterning the first silicon layer 120, the diaphragm 130 including the first electrode layer 132, the first electrode pad 136, and the first connection pattern 138 are formed. can be obtained. Additionally, a first anchor 140 for fixing the diaphragm 130 on the substrate 102 may be formed on a portion of the substrate 102 exposed by the first anchor channel 112. . For example, the diaphragm 130 may include the first electrode layer 132 and an edge portion 134 surrounding the first electrode layer 132, as shown in FIG. 3 . The first anchor 140 includes an inner wall portion 142 formed on a first inner surface of the first anchor channel 112 adjacent to the diaphragm 130, and an inner wall portion 142 facing the first inner surface. an outer wall portion 146 formed on the second inner surface of the first anchor channel 112, and a bottom portion formed on the substrate 102 between the inner wall portion 142 and the outer wall portion 146 ( 148) may be included.

In particular, by patterning the first silicon layer 120, a plurality of ventilation holes 143 penetrating the inner wall 142 may be formed, and a plurality of support patterns for supporting the diaphragm 130 may be formed. (144) can be formed. For example, on the first silicon layer 120, the diaphragm 130, the support patterns 144 of the first anchor 140, the outer wall 146 and the bottom 148, and the first anchor 140 are formed on the first silicon layer 120. After forming a photoresist pattern (not shown) covering the areas where the electrode pad 136 and the first connection pattern 148 will be formed, an etching process using the photoresist pattern as an etch mask is performed on the first insulating material. This may be performed until layer 110 is exposed.

Referring to FIG. 9, a second layer is formed on the first insulating layer 110, the diaphragm 130, the first electrode pad 136, the first connection pattern 138, and the first anchor 140. An insulating layer 150 may be formed. For example, the second insulating layer 150 may include silicon oxide and may be formed conformally, that is, to have a substantially uniform thickness, through a chemical vapor deposition process. Subsequently, the second silicon layer 160 may be conformally formed on the second insulating layer 150 to have a substantially uniform thickness. For example, the second silicon layer 160 may be a polysilicon layer formed through a chemical vapor deposition process.

Referring to FIG. 10, an ion implantation process may be performed to form the second silicon layer 160 as a conductive layer (not shown), that is, an impurity-doped polysilicon layer. Subsequently, the conductive layer is patterned to form a second electrode layer 172 and a second electrode pad 174 corresponding to the first electrode layer 132, and the second electrode layer 172 and the second electrode pad 174. A second connection pattern 176 (see FIG. 1) can be formed to connect. That is, as shown, the remaining portions of the conductive layer except for the second electrode layer 172, the second electrode pad 174, and the second connection pattern 176 can be removed. For example, a photoresist pattern exposing the remaining portions of the conductive layer except for the portion where the second electrode layer 172, the second electrode pad 174, and the second connection pattern 176 are to be formed on the conductive layer. After formation, an etching process using the photoresist pattern as an etch mask may be performed until the second insulating layer 150 is exposed.

Referring to FIG. 11, the second electrode layer 172 and a portion of the second insulating layer 150 are removed to form protrusions 186 (see FIG. 12) extending toward the first electrode layer 132. A plurality of holes 178 may be formed for The holes 178 may have a predetermined depth penetrating the second electrode layer 172 and extending to a portion of the second insulating layer 150 . For example, after forming a photoresist pattern (not shown) on the second electrode layer 172 to expose portions of the second electrode layer 172 where the holes 178 will be formed, the photoresist pattern is applied as an etch mask. An anisotropic etching process using may be performed for a preset time.

In addition, the second insulating layer 150 and the first insulating layer 110 may be patterned to form a second anchor channel 180 in the shape of a circular ring surrounding the first anchor 140. For example, after forming a photoresist pattern (not shown) on the second insulating layer 150 to expose portions of the second insulating layer 150 where the second anchor channel 180 will be formed, the photoresist pattern (not shown) is formed on the second insulating layer 150. An anisotropic etching process using a resist pattern as an etch mask may be performed until the upper surface of the substrate 102 is exposed.

Referring to FIG. 12, after forming the holes 178 and the second anchor channel 180, the support layer 182 is formed on the second electrode layer 172 and the second insulating layer 150 to be substantially uniform. It can be formed conformally in thickness. As a result, the back plate 170 including the second electrode layer 172 and the support layer 182 may be formed on the substrate 102. For example, the support layer 182 may be a silicon nitride layer formed through a chemical vapor deposition process. In particular, the support layer 182 may be formed to fill the holes 178, thereby forming protrusions 186 extending downward from the support layer 182 through the second electrode layer 172. It can be. Additionally, a portion of the support layer 182 formed in the second anchor channel 180 may be used as a second anchor 188 for fixing the support layer 182 on the substrate 102.

Referring to FIG. 13, a first opening 190 is formed by patterning the support layer 182 and the second insulating layer 150 to expose the first electrode pad 136 and the second electrode pad 174, respectively. and a second opening 192 may be formed. For example, a photoresist pattern (not shown) is formed on the support layer 182 to expose portions of the support layer 182 corresponding to the first electrode pad 136 and the second electrode pad 174. Afterwards, the first opening 190 and the second opening 192 can be formed through an anisotropic etching process using the photoresist pattern as an etch mask.

Referring to FIG. 14, a first bonding pad 194 and a second bonding pad 196 may be formed on the first electrode pad 136 and the second electrode pad 174, respectively. For example, the first bonding pad 194 and the second bonding pad 196 may be made of a metal such as aluminum, by forming an aluminum layer on the support layer 182 and then patterning the aluminum layer. can be formed.

Referring to FIG. 15, the support layer 182 and the second electrode layer 172 may be patterned to form a plurality of air holes 198. For example, a photoresist pattern (not shown) is formed on the support layer 182 to expose areas where the air holes 198 will be formed, and then an anisotropic etching process is performed using the photoresist pattern as an etch mask. Air holes 198 may be formed.

Referring to FIG. 16, a back grinding process may be performed to reduce the thickness of the substrate 102, and a cavity 104 penetrating the substrate 102 may be formed. The cavity 104 may be formed to correspond to the diaphragm 130 through an anisotropic etching process.

Referring to FIG. 17, after forming the cavity 104, a portion of the first insulating layer 110 formed inside the second anchor 188 is formed between the diaphragm 130 and the back plate 170. A portion of the second insulating layer 150 formed may be removed through a wet etching process. At this time, the etchant may be supplied between the diaphragm 130 and the back plate 170 through the air holes 198 and the vents 143. As a result, the air holes 198 may be connected to the air gap AG, and the cavity 104 may be connected to the air gap AG through the vents 143.

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will be able to understand that it exists.

100: MEMS microphone 102: substrate
104: cavity 110: first insulating layer
112: first anchor channel 120: first silicon layer
130: Vibration plate 132: First electrode layer
136: first electrode pad 138: first connection pattern
140: first anchor 142: inner wall
143: vent 144: support pattern
146: outer wall 148: bottom
150: second insulating layer 160: second silicon layer
170: back plate 172: second electrode layer
174: second electrode pad 176: second connection pattern
180: second anchor channel 182: support layer
186: Protrusion 188: Second anchor channel
194: first bonding pad 196: second bonding pad
198: air hole

Claims (20)

A vibration plate disposed on top of the substrate;
a first anchor disposed on the substrate and configured to secure the diaphragm to the substrate; and
Including a back plate disposed on an upper portion of the diaphragm,
The first anchor is a MEMS microphone characterized in that it has a plurality of ventilation holes connected to the air gap between the diaphragm and the back plate. The method of claim 1, wherein the first anchor includes a plurality of support patterns connected to edge portions of the diaphragm,
A MEMS microphone, wherein the plurality of vents are defined by the plurality of support patterns. The MEMS microphone of claim 2, wherein the first anchor further includes a ring-shaped bottom portion disposed on the substrate to surround the plurality of support patterns. The method of claim 1, wherein the substrate has a cavity penetrating the substrate to correspond to the diaphragm,
The first anchor is a MEMS microphone characterized in that it has a ring shape surrounding the diaphragm and the cavity. The method of claim 4, wherein the first anchor is:
an inner wall configured to surround the diaphragm and the cavity;
an outer wall portion configured to surround the inner wall portion,
A bottom portion disposed on the substrate between the inner wall portion and the outer wall portion,
The diaphragm is connected to the upper part of the inner wall,
A MEMS microphone, wherein the plurality of vents are formed through the inner wall. The method of claim 1, wherein the back plate is:
a second electrode layer disposed to correspond to the diaphragm,
It is disposed on the second electrode layer and includes a support layer for supporting the second electrode layer,
The MEMS microphone is characterized in that the second electrode layer is attached to the lower surface of the support layer. The method of claim 6, wherein the diaphragm includes a first electrode layer corresponding to the second electrode layer,
A MEMS microphone, wherein the second electrode layer and the first electrode layer have the same size. The method of claim 7, further comprising a second anchor disposed on the substrate and configured to secure the support layer to the substrate,
The first anchor has a ring shape surrounding the vibration plate,
The MEMS microphone is characterized in that the second anchor has a ring shape surrounding the first anchor. 9. The method of claim 8, comprising: a first insulating layer disposed on the substrate to surround the second anchor;
a second insulating layer disposed on the first insulating layer to surround the second anchor;
a first electrode pad disposed on the first insulating layer and electrically connected to the first electrode layer;
Further comprising a second electrode pad disposed on the second insulating layer and electrically connected to the second electrode layer,
A MEMS microphone, characterized in that an edge portion of the support layer is disposed on the second insulating layer. 10. The method of claim 9, comprising: a first bonding pad connected to the first electrode pad through an edge of the support layer and the second insulating layer;
The MEMS microphone further includes a second bonding pad connected to the second electrode pad through an edge portion of the support layer. The method of claim 7, wherein the back plate is:
The MEMS microphone further includes a plurality of protrusions that penetrate the second electrode layer and protrude from the support layer toward the diaphragm to prevent the second electrode layer and the first electrode layer from contacting each other. The MEMS microphone according to claim 1, wherein the back plate has a plurality of air holes connected to the air gap. A substrate having a cavity;
a diaphragm disposed on an upper portion of the substrate to correspond to the cavity and including a first electrode layer;
a first anchor that has a ring shape surrounding the cavity and the diaphragm and is disposed on the substrate to secure the diaphragm to the substrate;
a back plate disposed on an upper portion of the diaphragm and including a second electrode layer corresponding to the first electrode layer; and
A second anchor has a ring shape surrounding the first anchor, is disposed on the substrate, and includes a second anchor for fixing the back plate to the substrate,
The back plate has a plurality of air holes connected to an air gap between the diaphragm and the back plate,
The first anchor is a MEMS microphone characterized in that it has a plurality of vents for connecting between the cavity and the air gap. The method of claim 13, wherein the first anchor is:
an inner wall portion including a plurality of support patterns connected to edge portions of the diaphragm;
a ring-shaped bottom portion disposed on the substrate to surround the inner wall portion;
It includes a ring-shaped outer wall portion disposed on the substrate to surround the bottom portion,
A MEMS microphone, wherein the plurality of vents are defined by the support patterns. forming a first insulating layer on a substrate;
patterning the first insulating layer to form a ring-shaped first anchor channel that partially exposes the substrate;
forming a diaphragm on the first insulating layer and a first anchor in the first anchor channel for fixing the diaphragm to the substrate;
forming a plurality of vents by partially removing the first anchor;
forming a second insulating layer on the first insulating layer, the diaphragm, and the first anchor;
forming a back plate on the second insulating layer;
forming a cavity penetrating the substrate to correspond to the diaphragm; and
Removing a portion of the first insulating layer formed within the first anchor and a portion of the second insulating layer formed between the diaphragm and the back plate,
The method of manufacturing a MEMS microphone, characterized in that the cavity is connected to an air gap between the diaphragm and the back plate by the plurality of vents. The method of claim 15, wherein the first anchor is:
an inner wall formed on a first inner surface of the first anchor channel adjacent to the diaphragm;
an outer wall formed on a second inner surface of the first anchor channel facing the first inner surface;
It includes a bottom formed on the substrate between the inner wall and the outer wall,
A MEMS microphone manufacturing method, wherein the plurality of vents are formed by partially removing the inner wall portion. The method of claim 15, wherein forming the diaphragm and the first anchor comprises:
forming a first silicon layer on inner surfaces of the first insulating layer and the first anchor channel;
Forming a portion of the first silicon layer into a first electrode layer by performing an ion implantation process;
Comprising the step of patterning the first silicon layer to obtain the diaphragm and the first anchor,
The diaphragm includes the first electrode layer,
A MEMS microphone manufacturing method, characterized in that a portion of the first silicon layer formed in the first anchor channel is used as the first anchor. The method of claim 17, wherein forming the back plate comprises:
forming a second electrode layer corresponding to the first electrode layer on the second insulating layer;
A MEMS microphone manufacturing method comprising forming a support layer for supporting the second electrode layer on the second insulating layer and the second electrode layer. 19. The method of claim 18, further comprising patterning the second insulating layer and the first insulating layer to form a second anchor channel in a ring shape surrounding the first anchor and partially exposing the substrate,
A MEMS microphone manufacturing method, wherein a portion of the support layer formed on inner surfaces of the second anchor channel is used as a second anchor for fixing the back plate on the substrate. 16. The method of claim 15, further comprising forming a plurality of air holes penetrating the back plate,
A MEMS microphone manufacturing method, wherein a portion of the second insulating layer is removed by an etchant supplied through the plurality of vents and the plurality of air holes.

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