Semiconductor device and manufacturing method thereof

Abstract

The embodiment of the invention discloses a semiconductor device and a manufacturing method thereof. The semiconductor device includes: a substrate; the first insulating layer is positioned on one side of the substrate; the vibrating diaphragm is positioned on one side, far away from the substrate, of the first insulating layer; a plurality of micropores, a corrugated structure and a counter electrode are arranged on the vibrating diaphragm; the substrate, the first insulating layer and the vibrating diaphragm form a first cavity; the second insulating layer is positioned on one side, far away from the first insulating layer, of the diaphragm; the first backboard is located on the side, away from the vibrating diaphragm, of the second insulating layer; the vibrating diaphragm, the second insulating layer and the first back plate form a second cavity; the backboard electrode is located on the side, away from the second insulating layer, of the first backboard; the second back plate is positioned on one side, far away from the first back plate, of the back plate electrode; and the contact electrode is located in the second cavity and comprises a first sub-contact electrode and a second sub-contact electrode which are oppositely arranged. According to the technical scheme, the driving voltage of the semiconductor device can be reduced, the working stability of the semiconductor device is improved, and the reliability of the semiconductor device is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a semiconductor device and its manufacturing method. Background Technology

[0002] Micro-Electro-Mechanical Systems (MEMS) refer to systems designed and manufactured at the micrometer scale that integrate multiple components and are suitable for low-cost mass production. MEMS technology can integrate large-size devices that cannot be integrated by traditional integrated circuit processes into micro systems, enabling the development of devices with better performance and smaller size, as well as micro systems that integrate microsensors, microprocessors, and microactuators.

[0003] Radio frequency MEMS switching devices are one of the important applications of MEMS technology. Figure 1 This is a schematic diagram of the structure of a radio frequency microelectromechanical system (MEMS) switching device in related technologies. For example... Figure 1 As shown, the existing radio frequency MEMS switching device consists of a substrate 10, an insulating layer 20, a diaphragm 30 (including electrodes), a counter electrode 40, and contact electrodes 50. The contact electrodes 50 are located above the counter electrode 40 and below the diaphragm 30, respectively. When a certain driving voltage is applied between the diaphragm 30 and the counter electrode 40, the diaphragm 30 is displaced to the side of the counter electrode 40 due to electrostatic attraction, and the two contact electrodes 50 are connected together and conduction occurs. When the driving voltage is removed, the diaphragm 30 returns to its original position due to the elastic force, and the two contact electrodes 50 are disconnected, thereby realizing the switching function.

[0004] However, existing RF MEMS switching devices generally suffer from high drive voltage, poor stability at high speeds, and low reliability. Summary of the Invention

[0005] This invention provides a semiconductor device and a method for manufacturing the same, which reduces the driving voltage of the semiconductor device, improves the operating stability of the semiconductor device, and enhances the reliability of the semiconductor device.

[0006] According to one aspect of the present invention, a semiconductor device is provided, the semiconductor device comprising:

[0007] Substrate;

[0008] The first insulating layer is located on one side of the substrate;

[0009] A diaphragm is located on the side of the first insulating layer away from the substrate; the diaphragm has multiple micropores and a corrugated structure; the substrate, the first insulating layer, and the diaphragm constitute a first cavity; a counter electrode is also provided on the diaphragm.

[0010] The second insulating layer is located on the side of the diaphragm away from the first insulating layer;

[0011] The first back plate is located on the side of the second insulating layer away from the diaphragm; the diaphragm, the second insulating layer, and the first back plate constitute the second cavity;

[0012] The backplate electrode is located on the side of the first backplate away from the second insulating layer; the backplate electrode and the counter electrode jointly drive the diaphragm.

[0013] The second backplate is located on the side of the backplate electrode that is away from the first backplate;

[0014] The contact electrode is located in the second cavity; the contact electrode includes a first sub-contact electrode and a second sub-contact electrode disposed opposite to each other; the first sub-contact electrode is located at the center of the diaphragm and on the side of the diaphragm away from the substrate; the second sub-contact electrode is located on the side of the first backplate close to the substrate.

[0015] Optionally, the first cavity and the second cavity are in a vacuum environment or an inert gas atmosphere, and are connected by multiple micropores on the diaphragm.

[0016] Optionally, the semiconductor device may further include: a limiting structure;

[0017] The limiting structure is located on the side of the first backplate closest to the substrate.

[0018] Optionally, the limiting structure includes bumps and a second sub-contact electrode, wherein the surface of the second sub-contact electrode near the substrate is bumped.

[0019] Optionally, along the first direction, the thickness of the diaphragm is greater than or equal to 0.2 micrometers and less than or equal to 2 micrometers; the first direction is the direction from the substrate to the first insulating layer.

[0020] Optionally, along the first direction, the thickness of the first insulating layer is less than the thickness of the second insulating layer; or, the thickness of the first insulating layer is greater than the thickness of the second insulating layer.

[0021] Optionally, the thickness of the first insulating layer is greater than or equal to 0.5 micrometers and less than or equal to 3 micrometers.

[0022] Optionally, the thickness of the second insulating layer is greater than or equal to 1 micrometer and less than or equal to 5 micrometers.

[0023] Optionally, along the first direction, the thickness of the first backplate, the backplate electrode, and the second backplate is greater than or equal to 0.5 micrometers and less than or equal to 5 micrometers.

[0024] According to another aspect of the present invention, a method for manufacturing a semiconductor device is provided, the method comprising:

[0025] Provide substrate;

[0026] A first insulating layer is formed on one side of the substrate; the side of the first insulating layer away from the substrate has grooves arranged at intervals.

[0027] A diaphragm is formed on the side of the first insulating layer away from the substrate; the diaphragm has multiple micropores, a corrugated structure, and a counter electrode.

[0028] A first sub-contact electrode is formed on the side of the diaphragm away from the substrate; the first sub-contact electrode is located at the center of the diaphragm and is isolated from the counter electrode;

[0029] A second insulating layer is formed on the side of the diaphragm away from the first insulating layer;

[0030] A second sub-contact electrode and a first back plate are formed on the side of the second insulating layer away from the diaphragm; the second sub-contact electrode is disposed opposite to the first sub-contact electrode, and the second sub-contact electrode is located on the side of the first back plate closer to the substrate;

[0031] A backplate electrode is formed on the side of the first backplate away from the second insulating layer;

[0032] A second backplate is formed on the side of the backplate electrode away from the first backplate; the first backplate, the backplate electrode and the second backplate constitute a stacked backplate structure.

[0033] A through-hole is formed on the substrate or backplane structure, and part of the first insulating layer and part of the second insulating layer are removed through the through-hole to form a cavity;

[0034] The through hole is sealed; the substrate, the first insulating layer and the diaphragm form the first cavity; the diaphragm, the second insulating layer and the first back plate form the second cavity.

[0035] The technical solution of this invention provides a semiconductor device, which can be a contact-type radio frequency MEMS switch. A substrate, a first insulating layer, and a diaphragm together form a first cavity, while the diaphragm, a second insulating layer, and a first backplate form a second cavity. The first and second cavities are connected through micropores on the diaphragm, reducing the damping effect of the diaphragm on the gas, increasing the resonant frequency, and improving the high-speed operating stability of the semiconductor device. The corrugated structure on the diaphragm can reduce stress concentration, lower the driving voltage, ensure the stability of the diaphragm under repeated operation, and improve the reliability of the semiconductor device.

[0036] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a radio frequency microelectromechanical system (MEMS) switching device in related technologies;

[0039] Figure 2 This is a schematic diagram of the structure of a semiconductor device according to an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the structure of another semiconductor device provided according to an embodiment of the present invention;

[0041] Figure 4 This is a top view of the diaphragm structure provided according to an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the working process of a semiconductor device according to an embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of the structure of another semiconductor device provided according to an embodiment of the present invention;

[0044] Figure 7 This is a flowchart of a method for manufacturing a semiconductor device according to an embodiment of the present invention. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0047] Figure 2 This is a schematic diagram of the structure of a semiconductor device according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of another semiconductor device provided according to an embodiment of the present invention. Figure 2 and Figure 3 As shown, the semiconductor device includes: a substrate 10; a first insulating layer 201 located on one side of the substrate 10; a diaphragm 30 located on the side of the first insulating layer 201 away from the substrate 10; the diaphragm 30 having a plurality of micropores 301 and a corrugated structure 302; the substrate 10, the first insulating layer 201, and the diaphragm 30 forming a first cavity 101; a counter electrode also being disposed on the diaphragm 30; a second insulating layer 202 located on the side of the diaphragm 30 away from the first insulating layer 201; and a first backplate 60 located on the side of the second insulating layer 202 away from the diaphragm 30; the diaphragm 30, the second insulating layer 202, and the first backplate 60 forming a... A second cavity 102 is formed; a back plate electrode 70 is located on the side of the first back plate 60 away from the second insulating layer 202; the back plate electrode 70 and the counter electrode jointly drive the diaphragm 30; a second back plate 80 is located on the side of the back plate electrode 70 away from the first back plate 60; a contact electrode 50 is located in the second cavity 102; the contact electrode 50 includes a first sub-contact electrode 501 and a second sub-contact electrode 502 disposed opposite to each other; the first sub-contact electrode 501 is located at the center of the diaphragm 30 and on the side of the diaphragm 30 away from the substrate 10; the second sub-contact electrode 502 is located on the side of the first back plate 60 close to the substrate 10.

[0048] In embodiments of the present invention, such as Figure 2 As shown, the semiconductor device also includes a bonding substrate 100. The bonding substrate 100 and the substrate 10 provide a supporting foundation for the semiconductor device. The bonding substrate 100 can be a carrier such as glass or single-crystal silicon. The substrate 10 can be a semiconductor material such as single-crystal silicon, possessing good mechanical stability and insulation properties. The semiconductor device formed in this embodiment of the invention can be a contact-type radio frequency MEMS switch device. Figure 2In the structure shown, the bonding substrate 100, the substrate 10, the first insulating layer 201 and the diaphragm 30 together constitute the first cavity 101. Figure 3 In the structure shown, the first cavity 101 is composed of a substrate 10, a first insulating layer 201 and a diaphragm 30.

[0049] Figure 4 This is a top view schematic diagram of the diaphragm structure provided according to an embodiment of the present invention. Figures 2-4 As shown, the diaphragm 30 is the core moving component of the contact-type RF MEMS switching device, located above the first insulating layer 201. The diaphragm 30 or its conductive layer can serve as the counter electrode. Multiple micro-holes 301 on the diaphragm 30 are used to balance the air pressure inside and outside the first cavity 101 and the second cavity 102, preventing deformation of the diaphragm 30 due to pressure differences during semiconductor device processing or operation. The corrugated structure 302 enhances the elastic deformation capability of the diaphragm 30, ensuring that the diaphragm 30 can quickly and stably displace under the action of an electric field, and is less prone to plastic fatigue. The first insulating layer 201 and the second insulating layer 202 are insulating isolation components, located on opposite sides of the diaphragm 30. The first insulating layer 201 isolates the substrate 10 from the diaphragm 30, preventing electrical signal crosstalk. The second insulating layer 202 isolates the diaphragm 30 from the first backplate 60, preventing electrode short circuits in non-operating states, and providing a stable spatial boundary for the displacement of the diaphragm 30. The first backplate 60 serves as the opposing support structure for the diaphragm 30, and together with the diaphragm 30 and the second insulating layer 202, it forms the second cavity 102. The second backplate 80 is located above the backplate electrode 70 and is mainly used to protect the backplate electrode 70 from wear or corrosion by the external environment. At the same time, it can help optimize the RF performance of the contact-type RF MEMS switching device.

[0050] The contact electrode 50 is the core signal control electrode, consisting of a first sub-contact electrode 501 and a second sub-contact electrode 502 arranged opposite to each other. The first sub-contact electrode 501 is located at the center of the diaphragm 30, isolated from the counter electrode, and is a movable contact. The second sub-contact electrode 502 is located on the side of the first backplate 60 near the substrate 10 and is a fixed contact. The contact and separation of the first sub-contact electrode 501 and the second sub-contact electrode 502 determine the on / off state of the radio frequency signal. The backplate electrode 70, as the driving electrode, is located between the first backplate 60 and the second backplate 80. It generates an electric field with the diaphragm 30 (or the counter electrode disposed on its surface), generating electrostatic force to drive the diaphragm 30 to move and achieve the switching action. The first cavity 101 and the second cavity 102 provide effective space to ensure the effective operation of the diaphragm 30. The first cavity 101 and the second cavity 102 are connected through micropores 301 on the diaphragm 30, reducing the damping effect of the diaphragm 30 on the gas, increasing the resonant frequency, and improving the high-speed operating stability of the semiconductor device. The corrugated structure 302 on the diaphragm 30 can reduce stress concentration on the diaphragm 30, lower the driving voltage, ensure the stability of the diaphragm 30 under repeated operation, and improve the reliability of semiconductor devices.

[0051] Figure 5 This is a schematic diagram illustrating the working process of a semiconductor device according to an embodiment of the present invention. Figure 5 As shown, the working principle of this contact-type RF MEMS switch is to drive the diaphragm 30 to move by electrostatic force, thereby realizing the switching on and off of the contact electrode 50. The specific working process is as follows:

[0052] When no driving voltage is applied to the backplate electrode 70, the diaphragm 30 maintains a natural equilibrium state under the action of its own elastic force. At this time, the first sub-contact electrode 501 and the second sub-contact electrode 502 are in a separated state, and the radio frequency signal cannot form a path through the contact electrode 50, so the switch is in an "open" state. During this process, the first cavity 101 and the second cavity 102 maintain air pressure balance through the micropore 301 to ensure that the diaphragm 30 will not undergo unexpected displacement due to air pressure changes.

[0053] When a preset driving voltage is applied to the backplate electrode 70, an electrostatic field is formed between the backplate electrode 70 and the diaphragm 30 (or the counter electrode disposed on its surface). The electrostatic force generated by the electrostatic field overcomes the elastic force of the diaphragm 30, driving the diaphragm 30 to undergo elastic deformation in the direction of the first backplate 60. When the displacement of the diaphragm 30 reaches a preset value, the first sub-contact electrode 501 and the second sub-contact electrode 502 make close contact, forming a conduction path for the radio frequency signal, and the switch is in a "closed" state.

[0054] When the driving voltage of the back plate electrode 70 is removed, the electrostatic field disappears, and the diaphragm 30 returns to its initial equilibrium position under the elastic restoring force of its own corrugated structure 302. The first sub-contact electrode 501 separates from the second sub-contact electrode 502, and the switch returns to the open state.

[0055] The technical solution of this invention provides a semiconductor device, which can be a contact-type radio frequency MEMS switch. A substrate, a first insulating layer, and a diaphragm together form a first cavity, while the diaphragm, a second insulating layer, and a first backplate form a second cavity. The first and second cavities are connected through micropores on the diaphragm, reducing the damping effect of the diaphragm on the gas, increasing the resonant frequency, and improving the high-speed operating stability of the semiconductor device. The corrugated structure on the diaphragm can reduce stress concentration, lower the driving voltage, ensure the stability of the diaphragm under repeated operation, and improve the reliability of the semiconductor device.

[0056] In an optional embodiment of the present invention, reference is made to... Figure 2 and Figure 3 The first cavity 101 and the second cavity 102 are in a vacuum environment or an inert gas atmosphere, and are connected by a plurality of micropores 301 provided on the diaphragm 30.

[0057] In this embodiment of the invention, setting the first cavity 101 and the second cavity 102 to a vacuum environment or an inert gas atmosphere can optimize the vibration characteristics of the diaphragm 30 and improve sensing accuracy. Furthermore, a vacuum environment can isolate corrosive media such as water vapor or oxygen, protecting the diaphragm 30 or contact electrodes 50, etc.; the inert gas has stable chemical properties and does not react with the structures in the semiconductor device, protecting the semiconductor device structure and extending its service life. The first cavity 101 and the second cavity 102 are connected by multiple micropores 301 provided on the diaphragm 30, preventing abnormal pressure within the first cavity 101 or the second cavity 102 from damaging the chamber structure, thereby improving the stability and reliability of the semiconductor device.

[0058] In an optional embodiment of the present invention, reference is made to... Figure 2 and Figure 3 The semiconductor device also includes a limiting structure 90; the limiting structure 90 is located on the side of the first backplate 60 near the substrate 10.

[0059] In an optional embodiment of the present invention, reference is made to... Figure 2 and Figure 3 The limiting structure 90 includes bumps and a second sub-contact electrode 502. The surface of the second sub-contact electrode 502 near the substrate 10 is bumped.

[0060] In this embodiment of the invention, a limiting structure 90 is provided on the side of the first backplate 60 near the substrate 10. This limiting structure 90 is composed of uniformly distributed bumps on the side of the first backplate 60 near the substrate 10. A portion of this limiting structure 90 is formed by a second sub-contact electrode 502, which has good conductivity. When a driving voltage is applied to the semiconductor device, the diaphragm 30 shifts towards the first backplate 60, and the bumps connect with the first sub-contact electrode 501 on the diaphragm 30, thus enabling the device to conduct. Simultaneously, the bumps can restrict the displacement of the diaphragm 30 during device operation, reducing the contact area between the diaphragm 30 and the first backplate 60, decreasing the adhesion force after the diaphragm 30 contacts the first backplate 60, and preventing the diaphragm 30 from remaining stuck to the first backplate 60 after the driving voltage is removed, thus improving the reliability of the semiconductor device.

[0061] In an optional embodiment of the present invention, reference is made to... Figure 2 and Figure 3 Along the first direction X, the thickness of the diaphragm 30 is greater than or equal to 0.2 micrometers and less than or equal to 2 micrometers; the first direction X is the direction from the substrate 10 to the first insulating layer 201.

[0062] In this embodiment of the invention, the thickness of the diaphragm 30 is set to be greater than or equal to 0.2 micrometers to avoid insufficient rigidity of the diaphragm 30 due to excessive thinness. Setting the thickness of the diaphragm 30 to be less than or equal to 2 micrometers can reduce the driving voltage and power consumption of the semiconductor device. Setting the thickness range of the diaphragm 30 can ensure mechanical reliability, extend the service life of the semiconductor device, optimize radio frequency performance, and reduce losses.

[0063] Figure 6 This is a schematic diagram of the structure of another semiconductor device provided according to an embodiment of the present invention. In an optional embodiment of the present invention, refer to... Figure 2 and Figure 3 Along the first direction X, the thickness of the first insulating layer 201 is less than the thickness of the second insulating layer 202. Alternatively, refer to... Figure 6 The thickness of the first insulating layer 201 is greater than the thickness of the second insulating layer 202.

[0064] In this embodiment of the invention, the thickness of the first insulating layer 201 can be less than or greater than the thickness of the second insulating layer 202. When the thickness of the first insulating layer 201 is greater than the thickness of the second insulating layer 202, such as... Figure 6 As shown, the first cavity 101 can be directly formed by the substrate 10, the first insulating layer 201 and the diaphragm 30, without the need to trench the substrate 10 or add a bonding substrate.

[0065] In an optional embodiment of the present invention, reference is made to... Figure 2 , Figure 3 or Figure 6The thickness of the first insulating layer 201 is greater than or equal to 0.5 micrometers and less than or equal to 3 micrometers.

[0066] In this embodiment of the invention, the thickness of the first insulating layer 201 is set to be greater than or equal to 0.5 micrometers and less than or equal to 3 micrometers, which can ensure insulation performance, avoid electrical crosstalk and breakdown, and balance the space of mechanical support and cavity.

[0067] In an optional embodiment of the present invention, reference is made to... Figure 2 , Figure 3 or Figure 6 The thickness of the second insulating layer 202 is greater than or equal to 1 micrometer and less than or equal to 5 micrometers.

[0068] In this embodiment of the invention, the thickness of the second insulating layer 202 is set to be greater than or equal to 1 micrometer and less than or equal to 5 micrometers, which can isolate the diaphragm 30 from the back plate electrode 70 and suppress interference of the drive signal. At the same time, the height of the second cavity 102 can be defined to ensure the accuracy of the switching action.

[0069] In an optional embodiment of the present invention, reference is made to... Figure 2 , Figure 3 or Figure 6 Along the first direction X, the thickness of the first backplate 60, the backplate electrode 70, and the second backplate 80 is greater than or equal to 0.5 micrometers and less than or equal to 5 micrometers.

[0070] In this embodiment of the invention, the thickness of the first backplate 60, the backplate electrode 70 and the second backplate 80 is set to be greater than or equal to 0.5 micrometers and less than or equal to 5 micrometers. This ensures that the stacked structure formed by the first backplate 60, the backplate electrode 70 and the second backplate 80 has sufficient mechanical rigidity and avoids excessive thickness from affecting the driving efficiency of the diaphragm 30, thereby improving radio frequency performance and reducing signal loss and interference.

[0071] Figure 7 This is a flowchart illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention. This embodiment is applicable to the manufacture of semiconductor devices, and the method for manufacturing the semiconductor device can be executed by a semiconductor device manufacturing apparatus. Figure 7 As shown, the method for manufacturing this semiconductor device includes:

[0072] S110 provides a substrate.

[0073] Specifically, we can provide single-crystal silicon substrates.

[0074] S120, A first insulating layer is formed on one side of the substrate; the side of the first insulating layer away from the substrate has grooves arranged at intervals.

[0075] Specifically, silicon oxide or similar materials can be deposited on one side of the substrate using a chemical vapor deposition process to form a first insulating layer. Multiple spaced trenches are then etched on the side of the first insulating layer away from the substrate to facilitate the formation of the diaphragm's corrugated structure in subsequent processes.

[0076] S130, a diaphragm is formed on the side of the first insulating layer away from the substrate; the diaphragm is provided with multiple micropores, a corrugated structure and a counter electrode.

[0077] Specifically, polysilicon, metal thin films, or composite conductive thin films are deposited on the side of the first insulating layer away from the substrate. Micropore patterns are formed using photolithography, followed by dry etching to form the diaphragm. The diaphragm itself or a portion of its pattern constitutes the counter electrode. The micropores reduce the damping effect of the diaphragm on the gas, increasing the resonant frequency and improving the high-speed operating stability of the formed semiconductor device. The corrugated structure on the diaphragm reduces stress concentration, lowers the driving voltage, ensures the stability of the diaphragm under repeated operation, and improves the reliability of the formed semiconductor device.

[0078] S140, A first sub-contact electrode is formed on the side of the diaphragm away from the substrate; the first sub-contact electrode is located at the center of the diaphragm and is isolated from the counter electrode.

[0079] Specifically, an insulating layer, such as silicon oxide or silicon nitride, is first deposited on the side of the diaphragm away from the substrate, followed by the deposition of multiple metal thin films, and the first sub-contact electrode is formed by photolithography and etching.

[0080] S150, A second insulating layer is formed on the side of the diaphragm away from the first insulating layer.

[0081] Specifically, on the side of the diaphragm away from the first insulating layer, silicon oxide and other materials are deposited using a chemical vapor deposition process to form a second insulating layer.

[0082] S160, a second sub-contact electrode and a first back plate are formed on the side of the second insulating layer away from the diaphragm; the second sub-contact electrode is disposed opposite to the first sub-contact electrode, and the second sub-contact electrode is located on the side of the first back plate closer to the substrate.

[0083] Specifically, a multilayer metal thin film is deposited on the side of the second insulating layer away from the diaphragm, and a second sub-contact electrode is formed by photolithography and etching. Then, silicon nitride or the like is deposited on the side of the second insulating layer away from the diaphragm by chemical vapor deposition to form the first backplate.

[0084] S170, a backplate electrode is formed on the side of the first backplate away from the second insulating layer.

[0085] Specifically, doped polysilicon or metal is deposited on the side of the first backplate away from the second insulating layer to form a backplate electrode. The backplate electrode generates an electric field with the counter electrode on the diaphragm, which in turn generates an electrostatic force to drive the diaphragm to move, thereby achieving the switching action.

[0086] S180, A second backplate is formed on the side of the backplate electrode away from the first backplate; the first backplate, the backplate electrode and the second backplate constitute a stacked backplate structure.

[0087] Specifically, silicon nitride or similar materials are deposited on the side of the backplate electrode away from the first backplate by chemical vapor deposition to form a second backplate.

[0088] S190. A through-hole is formed on the substrate or backplane structure, and a portion of the first insulating layer and a portion of the second insulating layer are removed through the through-hole to form a cavity.

[0089] Specifically, vias are formed on the substrate or backplane structure using photolithography and etching processes. Wet or dry etching processes are then used to remove portions of the first and second insulating layers through these vias, creating cavities. Wet processes include, but are not limited to, the use of buffered oxide etchant (BOE) or hydrofluoric acid (HF). Dry etching processes include, but are not limited to, the use of vapor hydrofluoric acid (VHF).

[0090] S200, the through hole is sealed; the substrate, the first insulating layer and the diaphragm form the first cavity; the diaphragm, the second insulating layer and the first back plate form the second cavity.

[0091] Specifically, in a vacuum environment or inert gas atmosphere, the vias are sealed by substrate bonding or thin film deposition to form a first and second sealed cavity. The interiors of the first and second cavities are connected by micropores.

[0092] The technical solution of this invention provides a method for manufacturing a semiconductor device, which can be a contact-type radio frequency MEMS switch device. The substrate, a first insulating layer, and a diaphragm together constitute a first cavity, while the diaphragm, a second insulating layer, and a first backplate constitute a second cavity. The first and second cavities are connected through micropores on the diaphragm, reducing the damping effect of the diaphragm on the gas, increasing the resonant frequency, and improving the high-speed operating stability of the semiconductor device. The corrugated structure on the diaphragm can reduce stress concentration, lower the driving voltage, ensure the stability of the diaphragm under repeated operation, and improve the reliability of the semiconductor device.

[0093] In an optional embodiment of the present invention, after forming the second sub-contact electrode and the first back plate on the side of the second insulating layer away from the diaphragm, the invention further includes forming a limiting structure on the side of the first back plate near the substrate.

[0094] Specifically, the limiting structure includes bumps and a second sub-contact electrode. The material of the bumps can be the same as that of the first backplate, which simplifies the manufacturing process. The formed limiting structure can restrict the displacement of the diaphragm during device operation, reduce the contact area between the diaphragm and the first backplate, reduce the adhesion force after the diaphragm contacts the first backplate, prevent the diaphragm from remaining stuck to the first backplate after the driving voltage is removed, and prevent it from returning to its original position, thereby improving the reliability of the formed semiconductor device.

[0095] It should be noted that the semiconductor device manufacturing method of the present invention can manufacture semiconductor devices that form any embodiment of the present invention.

[0096] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0097] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A semiconductor device, characterized by, The application relates to a diaphragm for a loudspeaker, which comprises: a substrate; a first insulating layer on one side of the substrate; a diaphragm on the side of the first insulating layer away from the substrate, the diaphragm being provided with a plurality of micro-holes and corrugations, the substrate, the first insulating layer and the diaphragm forming a first cavity, and the diaphragm being further provided with a counter electrode; a second insulating layer on the side of the diaphragm away from the first insulating layer; a first back plate on the side of the second insulating layer away from the diaphragm, the diaphragm, the second insulating layer and the first back plate forming a second cavity; a back plate electrode on the side of the first back plate away from the second insulating layer; the back plate electrode and the counter electrode jointly driving the diaphragm; a second back plate on the side of the back plate electrode away from the first back plate; a contact electrode in the second cavity, the contact electrode comprising a first sub-contact electrode and a second sub-contact electrode arranged oppositely, the first sub-contact electrode being located at the center of the diaphragm and on the side of the diaphragm away from the substrate, and the second sub-contact electrode being located on the side of the first back plate close to the substrate.

2. The semiconductor device according to claim 1, wherein The first cavity and the second cavity are in a vacuum environment or an inert gas atmosphere and are connected through the plurality of micro-holes provided on the diaphragm.

3. The semiconductor device of claim 1, wherein The application further comprises: a limiting structure; the limiting structure being located on the side of the first back plate close to the substrate.

4. The semiconductor device according to claim 3, wherein The limiting structure comprises a convex point and the second sub-contact electrode, the surface of the second sub-contact electrode on the side close to the substrate being convex.

5. The semiconductor device of claim 1, wherein In a first direction, the thickness of the diaphragm is greater than or equal to 0.2 microns and less than or equal to 2 microns, the first direction being the direction of the substrate pointing to the first insulating layer.

6. The semiconductor device of claim 1, wherein In the first direction, the thickness of the first insulating layer is less than the thickness of the second insulating layer, or the thickness of the first insulating layer is greater than the thickness of the second insulating layer.

7. The semiconductor device of claim 6, wherein, The thickness of the first insulating layer is greater than or equal to 0.5 microns and less than or equal to 3 microns.

8. The semiconductor device of claim 6, wherein, The thickness of the second insulating layer is greater than or equal to 1 micron and less than or equal to 5 microns.

9. The semiconductor device of claim 1, wherein, In the first direction, the thickness of the first back plate, the back plate electrode and the second back plate is greater than or equal to 0.5 microns and less than or equal to 5 microns.

10. A method of manufacturing a semiconductor device, characterized by The application relates to a diaphragm for a loudspeaker, which comprises: providing a substrate; forming a first insulating layer on one side of the substrate, the first insulating layer being provided with a plurality of grooves arranged at intervals on the side of the first insulating layer away from the substrate; forming a diaphragm on the side of the first insulating layer away from the substrate, the diaphragm being provided with a plurality of micro-holes, corrugations and a counter electrode; forming a first sub-contact electrode on the side of the diaphragm away from the substrate, the first sub-contact electrode being located at the center of the diaphragm and being arranged separately from the counter electrode; forming a second insulating layer on the side of the diaphragm away from the first insulating layer; forming a second sub-contact electrode and a first back plate on the side of the second insulating layer away from the diaphragm, the second sub-contact electrode being arranged oppositely to the first sub-contact electrode, and the second sub-contact electrode being located on the side of the first back plate close to the substrate; forming a back plate electrode on the side of the first back plate away from the second insulating layer; A second back plate is formed on a side of the back plate electrode away from the first back plate; the first back plate, the back plate electrode and the second back plate constitute a back plate structure arranged in layers; A through hole is formed on the substrate or the back plate structure, and part of the first insulating layer and part of the second insulating layer are removed through the through hole to form a cavity; The through hole is sealed; the substrate, the first insulating layer and the diaphragm constitute a first cavity; and the diaphragm, the second insulating layer and the first back plate constitute a second cavity.

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