TWI469912B - Structure of mems electroacoustic transducer and fabricating method thereof - Google Patents

Description

Microelectromechanical electroacoustic transducer structure and manufacturing method thereof

The present invention relates to a microelectromechanical structure and a method of fabricating the same, and more particularly to a microelectromechanical electroacoustic transducer structure and a method of fabricating the same.

An electroacoustic transducer can convert sound waves into electrical signals by means of a diaphragm or convert electrical signals into sound waves, which can be used as a microphone or a speaker. Electroacoustic transducers can be used in a wide range of applications, such as mobile phones, digital cameras, hands-free handsets and notebook computers in the computer communication industry, and can be applied to hearing aids and electronic ear products in biomedical devices.

With the rapid development of the electronics industry and the advancement of semiconductor process and packaging technology, the design of electroacoustic transducer products is moving towards the demand for multi-functionality. In order to achieve short, small, light, thin, power-saving and cheap, the development of small electro-acoustic transducers that can be integrated with wafers made by semiconductor processes is a major trend in the development of electro-acoustic transducers.

Micro-electro-mechanical systems (MEMS) electroacoustic transducers use mechanical integrated circuits to design mechanical and electronic components on twins. Taking microelectromechanical microphones as an example, in terms of their current development status, they are all designed using capacitive principles. The basic structure of the condenser microphone is mainly to fix the electrodes on the soft diaphragm and the rigid back plate, and there is a backside cavity between the diaphragm and the back plate. So that it can completely freely vibrate with the sound (freely Vibration). The electric field change formed between the vibrating diaphragm and the backing plate generates an electrical signal on the circuit.

In general, after forming the backside cavity, a polymeric layer is formed to enclose the diaphragm to create an air-tight environment. However, due to the fact that the material of the polymer layer is too soft, the sensitivity of the electroacoustic transducer is poor. In addition, in practice, the method of sealing the vibrating membrane with a polymer material has problems such as an excessively complicated process and difficulty in controlling the quality of the polymer layer.

In view of this, the object of the present invention is to provide a microelectromechanical electroacoustic transducer structure that can effectively enhance the sensitivity of a microelectromechanical electroacoustic transducer.

Another object of the present invention is to provide a method of fabricating a microelectromechanical electroacoustic transducer structure capable of producing a sealing layer of good quality.

It is still another object of the present invention to provide a method of fabricating a microelectromechanical electroacoustic transducer structure that can be easily combined with current processes and simplifies the process.

The invention provides a microelectromechanical electroacoustic transducer structure comprising a substrate, a vibrating membrane, a tantalum material layer and a conductive pattern. The substrate includes a region of microelectromechanical elements. The diaphragm has a plurality of openings and is disposed in the microelectromechanical element region. There is a first cavity between the diaphragm and the substrate. The enamel material layer is disposed on the vibrating membrane and encloses the vibrating membrane. The conductive pattern is disposed under the diaphragm in the MEMS region.

According to an embodiment of the present invention, in the microelectromechanical electroacoustic transducer structure described above, the material of the diaphragm is, for example, a metal material.

According to an embodiment of the present invention, in the microelectromechanical electroacoustic transducer structure described above, the shape of the diaphragm is, for example, a mesh.

According to an embodiment of the present invention, in the microelectromechanical electroacoustic transducer structure described above, the material of the germanium material layer is, for example, amorphous germanium or polycrystalline germanium.

According to an embodiment of the present invention, in the microelectromechanical electroacoustic transducer structure, the vent hole is further disposed in the substrate in the MEMS region.

According to an embodiment of the present invention, in the microelectromechanical electroacoustic transducer structure, the vent hole region is further included to communicate with the MEMS element region.

According to an embodiment of the present invention, in the microelectromechanical electroacoustic transducer structure, the vent layer further includes a vent hole and is disposed in the vent area. Wherein, there is a second cavity between the vent layer and the substrate, and the second cavity communicates with the first cavity.

According to an embodiment of the present invention, in the microelectromechanical electroacoustic transducer structure described above, the material of the vent layer is, for example, a metal material.

According to an embodiment of the present invention, in the microelectromechanical electroacoustic transducer structure, the protection ring structure is further disposed on at least one side of the microelectromechanical element region.

The invention provides a method for manufacturing a microelectromechanical electroacoustic transducer structure, comprising the following steps. First, a substrate is provided, the substrate including a circuit region and a microelectromechanical device region. Then, a first metal interconnect structure is formed on the front surface of the substrate in the circuit region, and a first dielectric layer structure on the front surface of the substrate is formed in the microelectromechanical device region, and is located in the first dielectric layer structure. a conductive pattern and a vibration having a plurality of openings on the first dielectric layer structure membrane. Then, a sealing layer is formed on the diaphragm, and the sealing layer seals the diaphragm. Next, a second metal interconnect structure is formed on the first metal interconnect structure, and a second dielectric layer structure is formed on the sealing layer in the microelectromechanical device region. Thereafter, a first hard mask layer is formed on the second metal interconnect structure. Furthermore, a second hard mask layer is formed on the back side of the substrate in the circuit region. A vent is formed in the substrate in the MEMS region. Subsequently, the first hard mask layer and the second hard mask layer are used as masks to remove the first dielectric layer structure and the second dielectric layer structure.

According to an embodiment of the present invention, in the manufacturing method of the microelectromechanical electroacoustic transducer structure, the material of the sealing layer is, for example, amorphous germanium or polycrystalline germanium.

According to an embodiment of the present invention, in the manufacturing method of the microelectromechanical electroacoustic transducer structure, the material of the first hard mask layer is, for example, a tantalum material or a metal material.

According to an embodiment of the present invention, in the manufacturing method of the microelectromechanical electroacoustic transducer structure, the material of the second hard mask layer is, for example, a metal material.

According to an embodiment of the present invention, in the method of fabricating the microelectromechanical electroacoustic transducer structure, the method of forming the vent holes is, for example, removing a portion of the substrate from the back side of the substrate.

According to an embodiment of the present invention, in the manufacturing method of the microelectromechanical electroacoustic transducer structure, the first metal interconnect structure and the second metal interconnect structure are formed at the same time. A guard ring structure is formed between the circuit region and the MEMS element region.

The present invention provides another method of fabricating a microelectromechanical electroacoustic transducer structure, including the following steps. First, a substrate is provided, including a circuit region, a microelectromechanical device region, and a vent region. Then, a first metal interconnect structure is formed on the substrate in the circuit region, and a first dielectric layer structure on the substrate, a conductive pattern in the first dielectric layer structure, and the like are formed in the microelectromechanical device region. a first dielectric layer having a plurality of open diaphragms, and forming a first dielectric layer structure on the substrate and a vent layer on the first dielectric layer structure and having a vent hole in the vent region . Then, a sealing layer is formed on the diaphragm, and the sealing layer seals the diaphragm. Next, a second metal interconnect structure is formed on the first metal interconnect structure, and a second dielectric layer structure is formed on the sealing layer in the MEMS region and the vent layer in the vent region. Thereafter, a hard mask layer is formed on the second metal interconnect structure. Furthermore, the first dielectric layer structure and the second dielectric layer structure are removed by using a hard mask layer as a mask.

According to another embodiment of the present invention, in the manufacturing method of the microelectromechanical electroacoustic transducer structure described above, the material of the sealing layer is, for example, amorphous germanium or polycrystalline germanium.

According to another embodiment of the present invention, in the manufacturing method of the microelectromechanical electroacoustic transducer structure described above, the material of the hard mask layer is, for example, a tantalum material or a metal material.

According to another embodiment of the present invention, in the manufacturing method of the microelectromechanical electroacoustic transducer structure, the first metal interconnect structure and the second metal interconnect structure are formed, and the method further includes Forming a guard ring between the circuit region and the MEMS element region and between the MEMS element region and the vent region structure.

Based on the above, since the microelectromechanical electroacoustic transducer structure proposed by the present invention is used as a sealing layer of a tantalum material layer, the sensitivity of the microelectromechanical electroacoustic transducer can be effectively improved.

In addition, the manufacturing method of the microelectromechanical electroacoustic transducer structure proposed by the present invention can effectively control the film forming quality of the sealing layer, thereby producing a sealing layer of good quality.

On the other hand, in the manufacturing method of the microelectromechanical electroacoustic transducer structure proposed by the present invention, the step of forming the sealing layer is the step of removing the structure using the first dielectric layer and the second dielectric layer. Previously, it is easy to integrate with current semiconductor processes and to simplify process efficiency.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

1A to 1D are cross-sectional views showing a manufacturing process of a microelectromechanical electroacoustic transducer structure according to a first embodiment of the present invention.

First, referring to FIG. 1A, a substrate 100 is provided. The substrate 100 includes a circuit region 102 and a microelectromechanical device region 104. The substrate 100 has a front side 106 and a back side 108. The substrate 100 is, for example, a crucible substrate. The configuration relationship between the circuit area 102 and the MEMS element area 104 can be adjusted according to the needs of those skilled in the art. For example, in the first embodiment, the microelectromechanical element region 104 is disposed on the right side of the circuit region 102. In other embodiments, the microelectromechanical element region 104 can be disposed on the left side of the circuit region 102.

Next, a metal interconnect structure 110 is formed on the front side 106 of the substrate 100 within the circuit region 102. The method of fabricating the metal interconnect structure 110 is well known to those skilled in the art and will not be described again.

The dielectric layer structure 112, the conductive pattern 114, and the vibrating film 116 are formed in the microelectromechanical device region 104 while forming the metal interconnect structure 110. The conductive pattern 114 and the diaphragm 116 can be used as the lower electrode and the upper electrode of the capacitive electroacoustic transducer, respectively.

The dielectric layer structure 112 is located on the front side 106 of the substrate 100. In the present embodiment, the dielectric layer structure 112 is composed of, for example, three dielectric layers 112a, 112b, and 112c, but is not intended to limit the present invention. The material of the dielectric layer structure 112 is, for example, ruthenium oxide. The method of forming the dielectric layer structure 112 is, for example, formed together with a dielectric layer in the metal interconnect structure 110.

The conductive pattern 114 is located in the dielectric layer structure 112. The material of the conductive pattern 114 is, for example, a metal material such as copper or a doped polysilicon. The method of forming the conductive pattern 114 is formed, for example, with a gate of a transistor or a metal interconnect layer in the metal interconnect structure 110.

The diaphragm 116 is located on the dielectric layer structure 112 and has an opening 118. The shape of the diaphragm 116 is, for example, a mesh shape. The material of the diaphragm 116 is, for example, a metal material such as copper. The method of forming the diaphragm 116 is formed, for example, together with a metal interconnect layer in the metal interconnect structure 110.

In addition, while forming the metal interconnect structure 110, a guard ring structure 120 is more selectively formed between the circuit region 102 and the microelectromechanical device region 104, and can be used to protect the device during the subsequent process of removing the dielectric material. A dielectric layer in circuit region 102. The method of forming the guard ring structure 120 is, for example, Formed with the metal interconnect structure 110.

Then, referring to FIG. 1B, a sealing layer 122 is formed on the diaphragm 116, and the sealing layer 122 seals the diaphragm 116. The material of the sealing layer 122 is, for example, a germanium material such as amorphous germanium or polycrystalline germanium. When the material of the sealing layer 122 is a germanium material, the sensitivity of the microelectromechanical electroacoustic transducer can be improved. The sealing layer 122 is formed by, for example, forming a sealing material layer covering the vibrating film 116 by chemical vapor deposition, and then performing a patterning process on the sealing material layer to remove the sealing material layer other than the microelectromechanical element region 104. And formed. In addition, a sealing layer 122 can be selectively formed on the guard ring structure 120 in accordance with component design requirements.

Next, a metal interconnect structure 124 is formed on the metal interconnect structure 110. The metal interconnect structure 110 and the metal interconnect structure 124 form a metal interconnect structure 144. The method of fabricating the metal interconnect structure 124 is well known to those of ordinary skill in the art and will not be described herein.

A dielectric layer structure 126 is formed over the encapsulation layer 122 within the microelectromechanical device region 104 while forming the metal interconnect structure 124. In the present embodiment, the dielectric layer structure 126 is composed of, for example, three dielectric layers 126a, 126b, and 126c, but is not intended to limit the present invention. The material of the dielectric layer structure 126 is, for example, ruthenium oxide. The method of forming the dielectric layer structure 126 is formed, for example, with a dielectric layer in the metal interconnect structure 124.

In addition, while forming the metal interconnect structure 124, a guard ring structure 128 is more selectively formed between the circuit region 102 and the microelectromechanical device region 104, which can be used to protect the device during the subsequent process of removing the dielectric material. A dielectric layer in circuit region 102. Protection ring structure 128 and guard ring structure 120 A guard ring structure 130 is formed. The method of forming the guard ring structure 128 is formed, for example, with the metal interconnect structure 124.

Thereafter, a hard mask layer 132 is formed over the metal interconnect structure 124, and the hard mask layer 132 exposes the dielectric layer structure 126 within the microelectromechanical device region 104 for use in the subsequent removal of the dielectric material. The dielectric layer located in circuit region 102 is protected. The material of the hard mask layer 132 is, for example, a tantalum material such as amorphous germanium or polycrystalline germanium or a metal material such as aluminum. The hard mask layer 132 is formed by, for example, forming a hard mask material layer covering the metal interconnect structure 124 by a deposition method, and then performing a patterning process on the hard mask material layer to expose the microelectromechanical device region. The dielectric layer structure 126 within 104 is formed. In addition, a hard mask layer 132 can be selectively formed on the guard ring structure 128 in accordance with component design requirements.

Additionally, a dielectric layer 134 may be selectively formed over the metal interconnect structure 124 and the guard ring structure 128 prior to forming the hard mask layer 132, and the dielectric layer 134 is, for example, formed with a contact opening 136. The dielectric layer 134 may be a one-layer or multi-layer structure, and the material thereof is, for example, hafnium oxide or tantalum nitride.

Furthermore, referring to FIG. 1C, a hard mask layer 138 is formed on the back surface 108 of the substrate 100 in the circuit region 102, and the hard mask layer 138 exposes the back surface 108 of the substrate 100 in the microelectromechanical device region 104, which can be used. The substrate 100 located in the circuit region 102 is protected in a subsequent process of removing the dielectric material.

The material of the hard mask layer 138 is, for example, a metal material such as aluminum. The hard mask layer 138 is formed by, for example, forming a hard mask material layer covering the entire substrate 100 by a deposition method, and then performing a patterning process on the hard mask material layer to expose the microelectromechanical device region 104. Back side of substrate 100 Formed by 108. In addition, a hard mask layer 138 can be selectively formed on the back side 108 of the substrate 100 below the guard ring structure 128, in accordance with component design requirements.

Next, vent holes 140 are formed in the substrate 100 in the microelectromechanical element region 104. The vent hole 140 is formed by, for example, performing a patterning process on the substrate 100 in the MEMS element region 104 from the back surface 108 of the substrate 100 to remove a portion of the substrate 100.

Subsequently, referring to FIG. 1D, the dielectric layer structure 112 and the dielectric layer structure 126 are removed by using the hard mask layer 132 and the hard mask layer 138 as a mask, and a cavity is formed between the diaphragm 116 and the substrate 100. 142. The method of removing the dielectric layer structure 112 and the dielectric layer structure 126 is, for example, a wet etching method, and the etching liquid used is, for example, vapor hydrofluoric acid (VHF).

As is apparent from the first embodiment, the film forming quality of the sealing layer 122 can be effectively controlled by the manufacturing method of the above-described microelectromechanical electroacoustic transducer structure, so that the sealing layer 122 of good quality can be produced.

In addition, in the manufacturing method of the microelectromechanical electroacoustic transducer structure described above, the step of forming the sealing layer 122 is performed before the dielectric layer structure 112 and the dielectric layer structure 126 are removed, so that the current semiconductor process can be easily performed. Integrate and have the effect of streamlining the process.

2A to 2C are cross-sectional views showing a manufacturing process of a microelectromechanical electroacoustic transducer structure according to a second embodiment of the present invention.

First, referring to FIG. 2A, a substrate 200 is provided. The substrate 200 includes a circuit region 202, a microelectromechanical device region 204, and a vent region 206. The substrate 200 is, for example, a crucible substrate. Wherein, the circuit area 202, the microelectromechanical component area 204 and The configuration of the vent area 206 can be adjusted by one of ordinary skill in the art as needed. For example, in the second embodiment, circuit region 202 is disposed on one side of microelectromechanical device region 204 and vent region 206 is disposed on the other side of microelectromechanical device region 204. In other embodiments, circuit region 202 can be disposed on one side of vent region 206 and microelectromechanical device region 204 can be disposed on the other side of vent region 206.

Next, a metal interconnect structure 208 is formed over the substrate 200 within the circuit region 202. The method of fabricating the metal interconnect structure 208 is well known to those of ordinary skill in the art and will not be described herein.

A dielectric layer structure 210, a conductive pattern 212, and a diaphragm 214 are formed in the MEMS element region 204 while forming the metal interconnect structure 208. The conductive pattern 212 and the diaphragm 214 can be used as the lower electrode and the upper electrode of the capacitive electroacoustic transducer, respectively.

Dielectric layer structure 210 is located on substrate 200 within microelectromechanical device region 204. In the present embodiment, the dielectric layer structure 210 is composed of, for example, three dielectric layers 210a, 210b, and 210c, but is not intended to limit the present invention. The material of the dielectric layer structure 210 is, for example, ruthenium oxide. The method of forming the dielectric layer structure 210 is formed, for example, with a dielectric layer in the metal interconnect structure 208.

The conductive pattern 212 is located in the dielectric layer structure 210. The material of the conductive pattern 212 is, for example, a metal material such as copper or a doped polysilicon. The method of forming the conductive pattern 212 is, for example, formed together with a gate of a transistor or a metal interconnect layer in the metal interconnect structure 208.

The diaphragm 214 is located on the dielectric layer structure 210 and has an opening 216. The shape of the diaphragm 214 is, for example, a mesh shape. The material of the diaphragm 214 is, for example, Metal materials such as copper. The method of forming the diaphragm 214 is formed, for example, together with a metal interconnect layer in the metal interconnect structure 208.

In addition, a dielectric layer structure 210 and a vent layer 218 are formed in the vent region 206 while forming the metal interconnect structure 208. Forming the formed dielectric layer structure 210 within the MEMS element region 204 is simultaneously formed on the substrate 200 within the vent region 206.

The vent layer 218 is located on the dielectric layer structure 210 and has a vent 220. The material of the vent layer 218 is, for example, a metal material such as copper. The method of forming the vent layer 218 is formed, for example, with a metal interconnect layer in the metal interconnect structure 208.

On the other hand, while forming the metal interconnect structure 208, a guard ring structure 222 is more selectively formed between the circuit region 202 and the microelectromechanical device region 204 and between the microelectromechanical device region 204 and the vent region 206. The dielectric layer located in the circuit region 202 can be protected in a subsequent process of removing the dielectric material. The method of forming the guard ring structure 222 is formed, for example, with the metal interconnect structure 208.

Then, referring to FIG. 2B, a sealing layer 224 is formed on the diaphragm 214, and the sealing layer 224 seals the diaphragm 214. The material of the sealing layer 224 is, for example, a germanium material such as amorphous germanium or polycrystalline germanium. When the material of the sealing layer 224 is a germanium material, the sensitivity of the microelectromechanical electroacoustic transducer can be improved. The sealing layer 224 is formed by, for example, forming a sealing material layer covering the vibrating film 214 by chemical vapor deposition, and then performing a patterning process on the sealing material layer to remove the sealing material layer other than the microelectromechanical element region 204. And formed. In addition, the sealing layer 224 can be selectively topographically adapted to the component design requirements. Formed on the guard ring structure 222.

Next, a metal interconnect structure 226 is formed over the metal interconnect structure 208. The metal interconnect structure 208 and the metal interconnect structure 226 form a metal interconnect structure 244. The method of fabricating the metal interconnect structure 226 is well known to those of ordinary skill in the art and will not be described herein.

While forming the metal interconnect structure 226, a dielectric layer structure 228 is formed over the seal layer 224 in the MEMS region 204 and the vent layer 218 in the vent region 206. In the present embodiment, the dielectric layer structure 228 is composed of, for example, three dielectric layers 228a, 228b, and 228c, but is not intended to limit the present invention. The material of the dielectric layer structure 228 is, for example, ruthenium oxide. The method of forming the dielectric layer structure 228 is formed, for example, with a dielectric layer in the metal interconnect structure 226.

In addition, while forming the metal interconnect structure 226, a guard ring structure 230 is more selectively formed between the circuit region 202 and the microelectromechanical device region 204 and between the microelectromechanical device region 204 and the vent region 206. The dielectric layer located in circuit region 202 is protected in a subsequent process of removing the dielectric material. The guard ring structure 230 and the guard ring structure 222 form a guard ring structure 232. The method of forming the guard ring structure 230 is formed, for example, with the metal interconnect structure 226.

Thereafter, a hard mask layer 234 is formed over the metal interconnect structure 226, and the hard mask layer 234 exposes the dielectric layer structure 228 within the MEMS region 204 and the vent region 206 for subsequent movement The dielectric layer located in circuit region 202 is protected in a process other than dielectric material.

The material of the hard mask layer 234 is, for example, an amorphous material such as amorphous or polycrystalline silicon. Or metal materials such as aluminum. The hard mask layer 234 is formed by, for example, forming a hard mask material layer covering the metal interconnect structure 234 by a deposition method, and then performing a patterning process on the hard mask material layer to expose the microelectromechanical device region. The dielectric layer structure 228 within 204 is formed. In addition, a hard mask layer 234 can be selectively formed on the guard ring structure 230 in accordance with component design requirements.

Additionally, a dielectric layer 236 can be selectively formed over the metal interconnect structure 226 and the guard ring structure 230 prior to forming the hard mask layer 234, and the dielectric layer 236 is, for example, formed with a contact opening 238. The dielectric layer 238 may be one or more layers of a material such as hafnium oxide or tantalum nitride.

Moreover, referring to FIG. 2C, the dielectric layer structure 210 and the dielectric layer structure 228 are removed by using the hard mask layer 234 as a mask, and a cavity 240 is formed between the vibration film 214 and the substrate 200. A cavity 242 is formed between the pore layer 218 and the substrate 200. Wherein, the cavity 240 and the cavity 242 communicate with each other. The method of removing the dielectric layer structure 210 and the dielectric layer structure 228 is, for example, a wet etching method, and the etching liquid used is, for example, vapor hydrofluoric acid (VHF).

Based on the above, the manufacturing method of the microelectromechanical electroacoustic transducer structure disclosed in the second embodiment can produce the sealing layer 224 of good quality, and can be integrated with the current semiconductor process to achieve the effect of simplifying the process.

Hereinafter, the microelectromechanical electroacoustic transducer structures of the third embodiment and the fourth embodiment of the present invention will be described with reference to FIGS. 1D and 2C. It should be noted that in the microelectromechanical electroacoustic transducer structures of the third embodiment and the fourth embodiment, the material of the sealing layer is a bismuth material, that is, the sealing layer is a bismuth material layer.

Referring to FIG. 1D, the microelectromechanical electroacoustic transducer structure of the third embodiment includes a substrate 100, a conductive pattern 114, a diaphragm 116, and a sealing layer 122. Substrate 100 includes a microelectromechanical element region 104. The diaphragm 116 has an opening 118 and is disposed within the microelectromechanical element region 104. There is a cavity 142 between the diaphragm 116 and the substrate 100. The sealing layer 122 is disposed on the vibrating membrane 116 and encloses the vibrating membrane 116. The sealing layer 122 is a layer of germanium material, and the material of the layer of germanium material is, for example, amorphous germanium or polycrystalline germanium. The conductive pattern 114 is disposed under the diaphragm 116 in the microelectromechanical element region 104.

In addition, the microelectromechanical electroacoustic transducer structure may further include a vent 140 disposed in the substrate 100 within the MEMS element region 104. Additionally, the microelectromechanical electroacoustic transducer structure can optionally include a guard ring structure 130 disposed on at least one side of the microelectromechanical element region 104. In this embodiment, the guard ring structure 130 is disposed, for example, between the circuit region 102 and the microelectromechanical device region 104.

However, since the materials, functions, and formation methods of the components of the microelectromechanical electroacoustic transducer structure in FIG. 1D have been described in detail in the first embodiment, they will not be described again.

It can be seen from the third embodiment that since the sealing layer 122 in the structure of the microelectromechanical electroacoustic transducer is a layer of germanium material, the reaction speed of the sealing layer 122 is fast, and the sensitivity of the microelectromechanical electroacoustic transducer can be effectively improved. degree.

Referring to FIG. 2C, the microelectromechanical electroacoustic transducer structure of the fourth embodiment includes a substrate 200, a conductive pattern 212, a diaphragm 214, and a sealing layer 224. Substrate 200 includes a microelectromechanical element region 204. The diaphragm 214 has an opening 216 and is disposed within the microelectromechanical element region 204. Wherein, in the diaphragm 214 There is a cavity 240 between the substrate 200 and the substrate 200. The sealing layer 224 is disposed on the vibrating membrane 214 and encloses the vibrating membrane 214. The sealing layer 224 is a layer of germanium material, and the material of the layer of germanium material is, for example, amorphous germanium or polycrystalline germanium. The conductive pattern 212 is disposed under the diaphragm 214 in the microelectromechanical element region 204.

In addition, the microelectromechanical electroacoustic transducer structure may further include a vent area 206 and a vent layer 218. The vent area 206 communicates with the MEMS element region 204, and the vent layer 218 has a vent 220 and is disposed within the vent area 206. There is a cavity 242 between the vent layer 218 and the substrate 200, and the cavity 242 communicates with the cavity 240. Additionally, the microelectromechanical electroacoustic transducer structure can optionally include a guard ring structure 232 disposed on at least one side of the microelectromechanical element region 204. In this embodiment, the guard ring structure 232 is disposed, for example, between the circuit region 202 and the MEMS element region 204 and between the MEMS element region 204 and the vent region 206.

However, since the materials, functions, and formation methods of the components of the microelectromechanical electroacoustic transducer structure in FIG. 2C have been described in detail in the first embodiment, they will not be described again.

It can be seen from the fourth embodiment that since the layer of germanium material is used as the sealing layer 224 in the structure of the microelectromechanical electroacoustic transducer, the sealing layer 224 can have a faster reaction speed, and can effectively improve the microelectromechanical power. The sensitivity of the acoustic transducer.

In summary, the above embodiment has at least the following advantages: 1. The microelectromechanical electroacoustic transducer structure of the above embodiment can effectively enhance the sensitivity of the microelectromechanical electroacoustic transducer.

2. The sealing layer of good quality can be produced by the manufacturing method of the microelectromechanical electroacoustic transducer structure of the above embodiment.

3. Since the manufacturing method of the microelectromechanical electroacoustic transducer structure of the above embodiment can be easily integrated with the current semiconductor process, the efficiency of the process can be simplified.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope is subject to the definition of the scope of the patent application attached.

100, 200‧‧‧ base

102, 202‧‧‧ circuit area

104, 204‧‧‧Microelectromechanical component area

106‧‧‧ positive

108‧‧‧Back

110, 124, 144, 208, 226, 244‧‧‧Metal interconnection structure

112, 126, 210, 228‧‧ dielectric layer structure

112a, 112b, 112c, 126a, 126b, 126c, 134, 210a, 210b, 210c, 228a, 228b, 228c, 236‧‧ dielectric layer

114, 212‧‧‧ conductive patterns

116, 214‧‧‧ vibrating membrane

118, 216‧‧‧ openings

120, 128, 130, 222, 230, 232‧‧‧ protection ring structure

122, 224‧‧‧ sealing layer

132, 138, 234‧‧‧ hard mask layer

136, 238‧‧ ‧ contact window opening

140, 220‧‧‧ vents

142, 240, 242‧‧‧ cavity

206‧‧‧vent area

218‧‧‧ vent layer

1A to 1D are cross-sectional views showing a manufacturing process of a microelectromechanical electroacoustic transducer structure according to a first embodiment of the present invention.

2A to 2C are cross-sectional views showing a manufacturing process of a microelectromechanical electroacoustic transducer structure according to a second embodiment of the present invention.

100‧‧‧Base

102‧‧‧Circuit area

104‧‧‧Microelectromechanical component area

106‧‧‧ positive

108‧‧‧Back

110, 124‧‧‧Metal interconnection structure

134‧‧‧ dielectric layer

114‧‧‧ conductive pattern

116‧‧‧Vibration membrane

118‧‧‧ openings

120, 128, 130‧‧‧ protection ring structure

122‧‧‧ Sealing layer

132, 138‧‧‧ hard mask layer

136‧‧‧Contact window opening

140‧‧‧vents

142‧‧‧ cavity

144‧‧‧Metal interconnect structure

Claims (20)

A microelectromechanical electroacoustic transducer structure comprising: a substrate comprising a microelectromechanical component region; a vibrating membrane having a plurality of openings disposed in the microelectromechanical component region, wherein the vibrating membrane and the substrate There is a first cavity; a layer of material disposed on the diaphragm and enclosing the diaphragm; and a conductive pattern disposed under the diaphragm in the MEMS region. The microelectromechanical electroacoustic transducer structure of claim 1, wherein the material of the diaphragm comprises a metal material. The microelectromechanical electroacoustic transducer structure according to claim 1, wherein the shape of the diaphragm comprises a mesh shape. The microelectromechanical electroacoustic transducer structure according to claim 1, wherein the material of the germanium material layer is amorphous germanium or polycrystalline germanium. The microelectromechanical electroacoustic transducer structure of claim 1, further comprising a first venting hole disposed in the substrate in the MEMS region. The microelectromechanical electroacoustic transducer structure of claim 1, further comprising a venting region communicating with the MEMS element region. The microelectromechanical electroacoustic transducer structure of claim 6, further comprising a vent layer having a second venting hole disposed in the venting region, wherein the venting layer and the venting layer There is a second cavity between the bases, and the second cavity communicates with the first cavity. The microelectromechanical electroacoustic transducer structure of claim 7, wherein the material of the vent layer comprises a metal material. The microelectromechanical electroacoustic transducer structure of claim 6, further comprising a guard ring structure disposed on at least one side of the microelectromechanical element region. The microelectromechanical electroacoustic transducer structure of claim 1, further comprising a guard ring structure disposed on at least one side of the microelectromechanical element region. A method of fabricating a microelectromechanical electroacoustic transducer structure includes: providing a substrate including a circuit region and a microelectromechanical device region; forming a first metal interconnect on a front surface of the substrate in the circuit region a first dielectric layer structure on the front surface of the substrate, a conductive pattern in the first dielectric layer structure, and a first dielectric layer structure in the MEMS region a vibrating membrane having a plurality of openings; forming a sealing layer on the vibrating membrane, the sealing layer enclosing the vibrating membrane; forming a second metal interconnecting structure on the first metal interconnecting structure, Simultaneously forming a second dielectric layer structure on the sealing layer in the MEMS region; forming a first hard mask layer on the second metal interconnect structure; and the substrate in the circuit region Forming a second hard mask layer on a back surface; forming a vent hole in the substrate in the MEMS region; The first dielectric layer and the second hard mask layer are used as a mask to remove the first dielectric layer structure and the second dielectric layer structure. The method of fabricating a microelectromechanical electroacoustic transducer structure according to claim 11, wherein the material of the sealing layer is amorphous germanium or polycrystalline germanium. The manufacturing method of the microelectromechanical electroacoustic transducer structure according to claim 11, wherein the material of the first hard mask layer is a tantalum material or a metal material. The method of fabricating a microelectromechanical electroacoustic transducer structure according to claim 11, wherein the material of the second hard mask layer comprises a metal material. The method of fabricating a microelectromechanical electroacoustic transducer structure according to claim 11, wherein the method of forming the vent includes removing a portion of the substrate from the back side of the substrate. The manufacturing method of the microelectromechanical electroacoustic transducer structure according to claim 11, wherein the first metal interconnect structure and the second metal interconnect structure are formed, and the circuit is further included in the circuit. A guard ring structure is formed between the region and the MEMS element region. A method for fabricating a microelectromechanical electroacoustic transducer structure includes: providing a substrate, including a circuit region, a microelectromechanical device region, and a vent region; forming a first metal on the substrate in the circuit region a wiring structure, simultaneously forming a first dielectric layer structure on the substrate, a conductive pattern and a bit in the first dielectric layer structure in the MEMS region a vibrating film having a plurality of openings on the first dielectric layer structure, and forming the first dielectric layer structure on the substrate and the first dielectric layer structure in the vent region and a venting layer having a venting hole; forming a sealing layer on the vibrating membrane, the sealing layer enclosing the vibrating membrane; forming a second metal interconnecting structure on the first metal interconnecting structure, and simultaneously Forming a second dielectric layer structure on the sealing layer in the MEMS region and the vent layer in the vent region; forming a hard mask layer on the second metal interconnect structure; The first dielectric layer structure and the second dielectric layer structure are removed by using the hard mask layer as a mask. The method of fabricating a microelectromechanical electroacoustic transducer structure according to claim 17, wherein the material of the sealing layer is amorphous germanium or polycrystalline germanium. The method for manufacturing a microelectromechanical electroacoustic transducer structure according to claim 17, wherein the material of the hard mask layer is a tantalum material or a metal material. The manufacturing method of the microelectromechanical electroacoustic transducer structure according to claim 17, wherein the first metal interconnect structure and the second metal interconnect structure are formed, and the circuit is further included in the circuit. A guard ring structure is formed between the region and the MEMS element region and between the MEMS element region and the vent region.