MEMS microphone and method of manufacturing the same

A MEMS microphone includes a substrate having a cavity, a back plate disposed over the substrate and having a plurality of acoustic holes, a diaphragm disposed over the substrate to cover the cavity, the diaphragm being disposed under the back plate to be spaced apart from the back plate, including venting holes communicating with the cavity, and sensing an acoustic pressure to create a displacement, a first insulation layer interposed between the substrate and the diaphragm to support the diaphragm, and the first insulation layer including an opening formed at a position corresponding to the cavity to expose the diaphragm, a second insulating layer formed over the substrate to cover an upper face of the back plate and an insulating interlayer formed between the first insulation layer and the second insulation layer, and the insulation interlayer being located outside the diaphragm and supporting the second insulation layer to make the back plate be spaced from the diaphragm. Thus, a process of manufacturing the MEMS microphone may be simplified.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No. 10-2016-0050886, filed on Apr. 26, 2016 and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which are incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to MEMS microphones capable of converting a sound wave into an electrical signal, and a method of manufacturing such a MEMS microphone. More particularly, embodiments described herein relate to capacitive MEMS microphones capable of detecting an acoustic pressure to create a displacement and output an acoustic signal.

BACKGROUND

Generally, a capacitive microphone utilizes a capacitance between a pair of electrodes facing each other to transmit an acoustic signal. The capacitive microphone can be manufactured by a semiconductor MEMS process to have an ultra-small size.

A MEMS microphone includes a bendable diaphragm and a back plate facing the diaphragm. The diaphragm is disposed apart from a substrate and the back plate to freely bend upward or downward in response to sound waves incident upon the diaphragm. The diaphragm can be a membrane structure to sense an acoustic pressure to create a displacement. In other words, when the acoustic pressure arrives at the diaphragm, the diaphragm may be bent toward the back plate due to the acoustic pressure. The displacement of the diaphragm can be sensed through a change of capacitance formed between the diaphragm and the back plate. As a result, sound can be converted into an electrical signal for output.

Since such a MEMS microphone is manufactured through a plurality of etching processes for patterning each of a series of layers using a corresponding mask, a manufacturing process for manufacturing the MEMS microphone is complex, requiring many masks for the manufacturing process. The MEMS microphone conventionally has an anchor for supporting the diaphragm apart from the substrate, and a chamber for forming a spacing area between the diaphragm and the back plate. The anchor and the chamber are formed through separate masks and etching processes. This increases the number of masks required for the manufacturing process of the MEMS microphone, which may cause a production cost and a processing time increase.

SUMMARY

The example embodiments of the present invention provide a MEMS microphone to achieve a simplification of a process by decreasing a number of masks required to produce a MEMS microphone.

The example embodiments of the present invention illustrate a method of manufacturing a MEMS microphone in which a decreased number of masks are required to produce a MEMS microphone.

According to an example embodiment of the present invention, a MEMS microphone includes a substrate having a cavity, a back plate disposed over the substrate and having a plurality of acoustic holes, a diaphragm disposed over the substrate to cover the cavity, the diaphragm being disposed under the back plate to be spaced apart from the back plate, including venting holes communicating with the cavity, and sensing an acoustic pressure to create a displacement. The MEMS microphone further includes a first insulation layer interposed between the substrate and the diaphragm to support the diaphragm, the first insulation layer including an opening formed at a position corresponding to the cavity to expose the diaphragm. The MEMS microphone further includes a second insulating layer formed over the substrate to cover an upper face of the back plate and an insulating interlayer formed between the first insulation layer and the second insulation layer, the insulating interlayer being located outside the vibration area and supporting the second insulation layer to space the back plate apart from the diaphragm.

In an example embodiment, the vent holes may communicate with the cavity, and the opening has an area large than that of the cavity.

In an example embodiment, the insulating interlayer may surround the diaphragm.

In an example embodiment, the back plate may include a plurality of dimple holes in a position corresponding to the cavity, and the second insulation layer includes a plurality of dimples protruding from a lower face of the back plate through the dimple holes.

In an example embodiment, the acoustic holes may penetrate through the second insulation layer and the back plate.

In an example embodiment, the MEMS microphone may further include a diaphragm pad formed on an upper surface of the first insulation layer to be electrically connected to the diaphragm, a back plate pad formed on an upper face of the insulating interlayer to be electrically connected to the back plate, a first pad electrode formed on the second insulation layer and on an upper face of the diaphragm pad to be electrically connected to the diaphragm pad and a second pad electrode formed on the second insulating layer and on an upper face of the back plate pad to be electrically connected to the back plate pad.

According to an example embodiment of the present invention, a MEMS microphone includes a substrate having a cavity, the substrate being divided into a vibration area and a peripheral area surrounding the vibration area, and a back plate disposed over the substrate and in the vibration area. The back plate has a plurality of acoustic holes and a diaphragm interposed between the substrate and the back plate to cover the cavity, the diaphragm being spaced apart from the back plate, including venting holes communicating with the cavity, and sensing an acoustic pressure to create a displacement. A first insulation layer is disposed over the substrate and under the diaphragm to support the diaphragm and to space the diaphragm apart from the substrate. The first insulation layer includes an opening in the vibration area to communicate with the cavity and to expose the diaphragm. A second insulating layer is formed over the substrate to cover an upper face of the back plate, and an insulating interlayer is interposed between the first insulation layer and the second insulation layer, and the insulating interlayer being located outside the diaphragm and supporting the second insulation layer to space the back plate from the diaphragm.

In an example embodiment, the vent holes may be formed in the vibration area and the opening may have an area larger than that of the cavity.

In an example embodiment, the insulating interlayer may surround the diaphragm.

In an example embodiment, the MEMS microphone may further include a diaphragm pad formed on an upper surface of the first insulation layer to be electrically connected to the diaphragm, a back plate pad formed on an upper face of the insulating interlayer to be electrically connected to the back plate, a first pad electrode formed on the second insulation layer and on an upper face of the diaphragm pad to be electrically connected to the diaphragm pad, and a second pad electrode formed on the second insulating layer and on an upper face of the back plate pad to be electrically connected to the back plate pad.

According to an example embodiment of the present invention of a method of manufacturing a MEMS microphone, a first silicon layer is formed on a first insulation layer formed on an upper surface of a substrate. The first silicon layer is patterned to form a diaphragm having a vent hole. Then, a sacrificial layer and a second silicon layer are sequentially formed on the first insulation layer to cover the diaphragm. After the second silicon layer is patterned to form a back plate facing the diaphragm, a second insulation layer is formed on the sacrificial layer to cover the back plate. The substrate is patterned to form a cavity to partially expose a portion of the first insulation layer positioned below the diaphragm. An exposed portion of the first insulation layer is removed through an etching process using the cavity to form an opening to expose the diaphragm. Then, a portion of the sacrificial layer located between the diaphragm and the back plate is removed through an etching process using the cavity to transform a portion of the sacrificial layer remaining outside the diaphragm into an insulating interlayer.

In an example embodiment of the present invention of a method of manufacturing a MEMS microphone, the second insulating layer and the back plate may be patterned to form a plurality of acoustic holes penetrating through the second insulating layer and the back plate, after forming the second insulation layer, wherein forming the insulating interlayer includes utilizing the cavity, the opening, the vent holes and the acoustic holes as flow paths of etchant for removing the sacrificial layer.

In an example embodiment, forming the diaphragm may include patterning the first silicon layer to form a diaphragm pad to be electrically connected to the diaphragm, and forming the back plate may include patterning the second silicon layer to form a back plate pad to be electrically connected to the back plate.

In an example embodiment of the present invention of a method of manufacturing a MEMS microphone, the second insulating layer and the sacrificial layer may be patterned to form a first pad contact hole of exposing the diaphragm pad and a second pad contact hole of exposing the back plate pad. After an electrode layer on the second insulation layer is formed to cover the first and second pad contact holes, the electrode layer may be patterned to form a first pad electrode to be electrically connected to the diaphragm pad exposed by the first contact hole, and a second pad electrode to be electrically connected to the back plate pad exposed by the second contact hole

In an example embodiment forming the back plate may include patterning the second silicon layer to form a plurality of dimple holes in the back plate and partially removing a portion of the sacrificial layer exposed through the dimple holes, and forming the second insulation layer may include filling up the dimple holes to form a plurality of dimples.

In an example embodiment, the insulating interlayer may be formed to surround the diaphragm, and the dimple holes may be formed in an area corresponding to the cavity.

According to an example embodiment of the present invention of a method of manufacturing a MEMS microphone, a first silicon layer is formed on a first insulation layer formed on an upper surface of a substrate. The first silicon layer is patterned through an etching process using a diaphragm pattern mask to form a diaphragm having a vent hole in a vibration area of the substrate. A sacrificial layer and a second silicon layer are sequentially formed on the first insulation layer to cover the diaphragm. The second silicon layer is patterned through an etching process using a back plate pattern mask to form a back plate in the vibration area. A second insulating layer is formed on the sacrificial layer to cover the back plate. The substrate is patterned through an etching process using a cavity pattern mask to form a cavity for partially exposing the first insulating layer in the vibration area. an etching process is performed using the cavity an etch mask to remove a portion of the first insulation layer exposed by the cavity such that an opening is formed in the first insulation layer to expose the diaphragm, and to remove a portion of the sacrificial layer in the vibration area to transform a remaining portion of the sacrificial layer into an insulating interlayer in a peripheral area.

In an example embodiment of the present invention of a method of manufacturing a MEMS microphone, the second insulating layer and the back plate may be patterned through an etching process using an acoustic hole pattern mask to form a plurality of acoustic holes passing through the second insulating layer and the back plate in the vibration area, wherein the cavities, the openings, the vent holes, and the acoustic holes serve as flow paths of the etchant for removing the sacrificial layer.

In an example embodiment, forming the back plate may include patterning the second silicon layer to form a plurality of dimple holes in the back plate and partially removing a portion of the sacrificial layer exposed through the dimple holes, and forming the second insulation layer may include filling up the dimple holes to form a plurality of dimples.

In an example embodiment, forming the diaphragm may include patterning the first silicon layer to form a diaphragm pad to be electrically connected to the diaphragm, and forming the back plate may include includes patterning the second silicon layer to form a back plate pad to be electrically connected to the back plate, the second insulating layer and the sacrificial layer may be patterned through an etching process using a contact hole mask to form a first pad contact hole of exposing the diaphragm pad and a second pad contact hole of exposing the back plate pad. An electrode layer may be further formed on the second insulation layer to cover the first and second pad contact holes, and the electrode layer may patterned to form a first pad electrode to be electrically connected to the diaphragm pad exposed by the first contact hole, and a second pad electrode to be electrically connected to the back plate pad exposed by the second contact hole.

According to example embodiments of the present invention as described above, the first insulation layer can support the diaphragm, and the insulating interlayer can support the second insulation layer with making the back plate from to be spaced from the diaphragm such that the MEMS microphone does not need to have a chamber portion for separating an anchor and the back plate from the diaphragm. Accordingly, masks and steps for forming the anchor and the chamber in the process for manufacturing the MEMS microphone can be omitted, so that the process can be simplified, the manufacturing cost can be reduced, and the process time can be shortened.

In addition, since the dimple holes are also formed in the process of forming the back plate, an additional process and a mask for forming the dimple holes are not required. As a result, the process time can be further shortened and the manufacturing cost can be reduced.

DETAILED DESCRIPTION OF THE DRAWINGS

Hereinafter, specific embodiments will be described in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein.

As an explicit definition used in this application, when a layer, a film, a region, or a plate is referred to as being ‘on’ another one, it can be directly on the other one, or one or more intervening layers, regions, or plates may also be present. By contrast, it will also be understood that when a layer, a region, or a plate is referred to as being ‘directly on’ another one, it is directly on the other one, and one or more intervening layers, regions, or plates do not exist. Also, although terms such as a first, a second, and a third are used to describe various components, compositions, regions, and layers in various embodiments of the present invention, the regions and the layers are not limited to these terms.

Furthermore, and solely for convenience of description, elements may be referred to as “above” or “below” one another. It will be understood that such description refers to the orientation shown in the Figure being described, and that in various uses and alternative embodiments these elements could be rotated or transposed in alternative arrangements and configurations.

In the following description, the technical terms are used only for explaining specific embodiments while not limiting the scope of the present invention. Unless otherwise defined herein, all the terms used herein, which include technical or scientific terms, may have the same meaning that is generally understood by those skilled in the art.

The depicted embodiments are described with reference to schematic diagrams of some embodiments of the present invention. Accordingly, changes in the shapes of the diagrams, for example, changes in manufacturing techniques and/or allowable errors, are sufficiently expected. The Figures are not necessarily drawn to scale. Accordingly, embodiments of the present invention are not described as being limited to specific shapes of areas described with diagrams and include deviations in the shapes and also the areas described with drawings are entirely schematic and their shapes do not represent accurate shapes and also do not limit the scope of the present invention.

FIG. 1is a plan view illustrating a MEMS microphone in accordance with an example embodiment of the present invention.FIG. 2is a cross sectional view taken along a line I-I′ inFIG. 1.

Referring toFIGS. 1 and 2, a MEMS microphone in accordance with an example embodiment of the present invention is capable of creating a displacement according to an acoustic pressure to convert sound wave into an electrical signal and output the electrical signal. The MEMS microphone includes a substrate110, a diaphragm120, a first insulation layer130, a back plate140, a second insulation layer150and an insulating interlayer160.

In particular, the substrate110is defined to be divided into a vibration area VA in which a membrane can vibrate in response to sound wave, and a peripheral area SA surrounding the vibration area VA. In the vibration area VA, a cavity112is formed.

The diaphragm120may be formed over the substrate110to cover the cavity112and to be exposed through the cavity112. The diaphragm120may be formed to have a membrane structure. An end portion of the diaphragm120may be positioned in the peripheral area SA. The diaphragm120may sense an acoustic pressure to create a displacement, and is apart from the substrate in order to be bendable upwardly or downwardly in response to the acoustic pressure. The diaphragm120may have an ion implantation region into which impurities are doped.

In an example embodiment, the diaphragm may have a shape of a disc plate, and the cavity may have a cylindrical shape, a shown inFIG. 1.

The first insulation layer130is disposed over the substrate110and under the diaphragm120. The first insulation layer130may support the diaphragm120while separating the diaphragm120from the substrate110. That is, the first insulation layer130may support an end portion of the diaphragm120to make the diaphragm120to be spaced apart from the substrate110such that the diaphragm120is separated both electrically and mechanically from the substrate110and the diaphragm120covers the cavity112.

Particularly, the first insulation layer130has an opening132by removing a portion of the first insulation layer, corresponding to the cavity to partially expose the diaphragm120through the cavity112. The diaphragm120is exposed through the opening132and the cavity112, and thus can be bent downward by the acoustic pressure which is applied to the diaphragm120.

In an embodiment of the present invention, the opening132may an area larger than that of the cavity112and identical to the vibration area VA. The first insulation layer130may support the end portion of the diaphragm120in the peripheral area SA.

As described above, the MEMS microphone100according to embodiments of the present invention is configured such that the first insulation layer130supports the diaphragm120to separate the diaphragm120from the substrate110without forming a separate anchor. Accordingly, the structure and manufacturing process of the MEMS microphone100can be simplified, and process times and manufacturing costs of the MEMS microphone100can be reduced.

Meanwhile, the back plate140may be disposed over the diaphragm120. The back plate140may be disposed in the vibration area VA and may be disposed to face the diaphragm120. As shown inFIG. 1, the back plate140may be formed in a circular shape. Further, the back plate140may be spaced apart from the diaphragm120to form an air gap AG between the back plate140and the diaphragm120. Like the diaphragm120, impurity doping process may be performed through an ion implantation process to form the back plate140.

As shown inFIG. 2, the back plate140is spaced apart from the diaphragm120such that the diaphragm120can be bent upward by the acoustic pressure. The air gap AG may be formed by removing a sacrificial layer positioned between the diaphragm120and the back plate140such that the diaphragm120is spaced apart from the back plate140.

In an example embodiment, the diaphragm120may have a plurality of vent holes122through which the air gap AG is communicated with the opening portion132of the first insulation layer130. The vent holes122penetrate through the diaphragm120to serve as a path of sound wave and a flow path through which an etchant flows for removing a sacrificial layer between the diaphragm120and the back plate140using the etchant. Further, the vent holes122may be formed in a region corresponding to the cavity112to communicate with the cavity112.

The second insulation layer150may be disposed over the substrate110over which the back plate140is formed. The second insulation layer140may cover an upper face of the back plate140.

The back plate140and the second insulation layer150may include a plurality of acoustic holes142through which sound waves pass. The acoustic holes142are formed through the back plate140and the second insulation layer150. Thus, the acoustic holes may communicate with the air gap AG.

The back plate140may have a plurality of dimple holes144and the second insulation layer150may have a plurality of dimples152corresponding to the dimple holes144. The dimple holes144are formed through the back plate140, and the dimples152are provided at a position where the dimple holes144are formed.

The dimples152may prevent the diaphragm120from adhering to the bottom surface of the back plate140. That is, when sound reaches to the diaphragm120, the diaphragm120may be bent in a semicircular shape toward the back plate140, and then return to its initial position. The degree of bending of the diaphragm120may vary depending on the strength of the sound. The upper face of the diaphragm120may be bent to contact the lower surface of the back plate140. When the diaphragm120is bent so much as to make contact with the back plate140, the diaphragm120may not return from the back plate140to the initial position. However, in case that the dimples152protrude from the lower face of the back plate140toward the diaphragm120, the dimples152may make the diaphragm120to be spaced apart from and the back plate140such that the diaphragm120can return to the initial position, even though the diaphragm120is so much bent as to make the diaphragm120to contact the back plate140.

The back plate140may be spaced apart from the diaphragm120. The insulation interlayer160may be interposed between the back plate140and the diaphragm120and may be positioned in the peripheral area SA. The insulating interlayer160may support the second insulation layer150to make the back plate140which is connected to a lower face to the second insulation layer150to be spaced apart from the diaphragm120. Since the insulating interlayer160instead of a chamber supports the second insulation150, it may be unnecessary to form the chamber for making the back plate140to be apart from the diaphragm120. Thus, the structure and manufacturing process of the MEMS microphone100can be simplified, and process times and manufacturing costs of the MEMS microphone100can be reduced.

Even though shown in detail in figures, a side portion of the air gap AG may be defined by the insulating interlayer160. Thus, the air gap AG may be formed in a region surrounded by the insulating interlayer160.

The diaphragm120may be connected to the diaphragm pad172, and the back plate140may be connected to the back plate pad174. The diaphragm pad172and the back plate pad174may be located in the peripheral area SA. The diaphragm pad172is provided on the upper surface of the second insulation layer150and is exposed through a first contact hole CH1formed by partially removing both the second insulating layer150and insulating interlayer160. The back plate pad174may be formed on the upper surface of the insulating interlayer160and may be exposed through a second contact hole CH2formed by partially removing the second insulation layer150.

The first and second pad electrodes182and184may be formed on the second insulation layer150. The first pad electrode182is located on the upper side of the diaphragm pad172and makes contact with the diaphragm pad172through the first contact hole CH1. Thus, the first pad electrode182is electrically connected to the diaphragm pad172. On the other hands, the second pad electrode184is positioned on the back plate pad174and makes contact with the back plate pad174through the second contact hole CH2. Thus, the second pad electrode184is electrically connected to the back plate pad174. Here, the first and second pad electrodes182and184may be transparent electrodes.

Hereinafter, the method of manufacturing the MEMS microphone will be described in detail with reference to the drawings.

FIG. 3is a flow chart illustrating a method of manufacturing a MEMS microphone in accordance with an example embodiment of the present invention.FIGS. 4 to 12are cross sectional views illustrating a method of manufacturing a MEMS microphone in accordance with an example embodiment of the present invention.

Referring toFIGS. 3 to 5, according to a method for manufacturing the MEMS microphone101in accordance with an example embodiment, a first silicon layer12is deposited on an upper face of a first insulation layer130formed on a substrate110, as shown inFIG. 4(step S105). Here, the first silicon layer12may be made of polysilicon.

Next, the first silicon layer12is patterned through an etching process using a diaphragm pattern mask to form a diaphragm120as shown inFIG. 5(step S110). A plurality of vent holes122may be formed in the diaphragm120through the etching process using the diaphragm pattern mask. A diaphragm pad172electrically connected to the diaphragm120may be formed on the substrate110in a peripheral area SA of the substrate110.

In an embodiment of the present invention, the method of manufacturing a MEMS microphone may further include a step of performing an ion implantation process against the first silicon layer12, prior to performing the etching process using the diaphragm pattern mask. Particularly, since the MEMS microphone100does not have a separate anchor being connected with an end portion of the diaphragm120, for supporting the diaphragm120which is to be spaced apart from the substrate110, a separate mask for performing the ion implantation process may not be required. The ion implantation of the diaphragm120is possible without using it. Accordingly, the method of manufacturing a MEMS microphone according to an embodiment of the present invention can reduce the number of masks, thereby reducing manufacturing costs.

FIGS. 3, 6 and 7, a sacrificial layer20and a second silicon layer14are formed in order on the first insulation layer130to cover the diaphragm120and the diaphragm pad172(Step S115). Here, the second silicon layer14may be made of polysilicon, and the sacrificial layer20may be made of silicon oxide, although in alternative embodiments other materials could be used that are differentially etchable with respect to one another.

Next, the second silicon layer14is patterned through an etching process using a back plate pattern mask to form the back plate140, as shown inFIG. 7(step S120). Dimple holes144may be also formed through the back plate140by performing the etching process using the back plate pattern mask, and the back plate pad174to be electrically connected to the back plate140may be formed on the sacrificial layer20in the peripheral region SA. At this time, portions of the sacrificial layer20, corresponding to the dimple holes144may be partially etched so that the dimples154(seeFIG. 2) protrude from a lower face of the back plate140.

Referring toFIGS. 3, 8 and 9, a second insulation layer150is formed on the sacrificial layer20to cover the back plate140(step S125). At this time, the dimples152may be formed through the dimple holes144.

Then, the second insulating layer150and the sacrificial layer20are patterned through an etching process using a contact hole pattern mask to form a first contact hole CH1to expose the diaphragm pad172, and a second contact hole CH2to expose the back plate pad174(step S130).

Next, an electrode layer (not shown) is formed on the second insulation layer150to partially fill up the first and second contact holes CH1and CH2(step S135).

Referring toFIGS. 3 and 10, the electrode layer is patterned through an etching process using an electrode pattern mask to form first and second pad electrodes182and184(step S140).

Referring toFIGS. 3 and 11, the second insulating layer150and the back plate140are patterned through an etching process using an acoustic hole pattern mask to form acoustic holes142(step S145).

Next, referring toFIGS. 3 and 12, the substrate110is patterned through an etching process using a cavity pattern mask to form a cavity112in a vibration area VA (step S150).

Referring toFIGS. 2, 3, and 12, a portion of the first insulation layer130exposed through the cavity112is removed through an etching process using the cavity112to form an opening portion132to expose the diaphragm120(step S155). At this time, the substrate110may be used as an etching mask for patterning the first insulating layer130, and the opening132may be formed to be larger than the cavity112. Here, HF vapor may be used as an etchant for forming the opening132.

Since the end portion of the diaphragm120is supported by the first insulation layer130, the MEMS microphone100need not have a separate anchor for supporting the diaphragm120from the substrate110. Accordingly, since the masks for patterning the first insulation layer130and for forming the anchor may not be required, manufacturing costs can be reduced and process times can be shortened compared to conventional MEMS microphones.

Subsequently, the etchant is supplied through the cavity112of the substrate110and the vent holes122to remove a portion of the sacrificial layer20located on the upper surface of the diaphragm120, thereby forming the air gap AG (step160). Thus, the MEMS microphone100is completed. At this time, the etchant may be also supplied to the sacrificial layer through the acoustic holes142which may serve as a flow path of the etching fluid.

The sacrificial layer20remains in the peripheral region SA to form an insulating interlayer160. The insulating interlayer160supports the second insulating layer150, and defines an air gap AG together with the lower face of the back plate140and the upper face of the diaphragm120. At this time, an etching area of the sacrificial layer20removed by the etchant can be controlled by the process time, that is, the etching process against the sacrificial layer20may be controlled depending on a predetermined size of the air gap AG.

In an embodiment of the present invention, steps S155and S160may be simultaneously performed, where the etchant is provided toward the substrate110downwardly and upwardly.

As described above, according to example embodiment of a MEMS microphone manufacturing method, the etching area of the sacrificial layer removed by the etchant can be controlled by the process time. Thus, the insulating interlayer160may make the back plate140to be spaced apart from the diaphragm120without forming a chamber portion. Accordingly, masks for patterning the sacrificial layer20and the first insulating layer120in order to form the chamber portion, and step for forming the chamber portion are not required. As a result, manufacturing costs and times of manufacturing the MEMS microphone can be reduced.

The first insulation layer130may support the end portion of the diaphragm120which is different from the prior art a separate additional member for supporting the diaphragm120such as an anchor such that a process of forming the anchor for supporting the diaphragm120can be omitted. Thus, the process can be simplified and the process time can be shortened. In addition, since the mask for forming the anchor and the mask for performing an ion implantation process against the diaphragm120may not be required. Thus, the manufacturing costs and times of manufacturing the MEMS microphone can be reduced.

Further, since the dimple holes144are also formed in the process of forming the back plate140using the back plate pattern mask, a separate additional process for forming the dimple holes144can be omitted.

Furthermore, while the step S125of forming the contact hole162before the step S135of forming the first and second contact holes CH1and CH2, the first contact hole CH1is formed The first and second contact holes CH1and CH2can be formed together by removing the sacrificial layer to be formed.

Thus, according to example embodiments of an method of the present invention totally six masks can be utilized to manufacture the MEMS microphone100to reduce the number of mask required, compared to the prior art, thereby simplifying the process, shortening the process times and saving the manufacturing costs.

Although the semiconductor gas sensors have been described with reference to the specific embodiments, they are not limited thereto. Therefore, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the appended claims.