Semiconductor device

Abstract

The utility model provides a semiconductor device, which comprises a substrate layer, an insulating layer and a functional layer which are sequentially stacked along a first direction layer, a cavity is arranged in the insulating layer, the functional layer comprises an elastic layer and a piezoelectric assembly, the elastic layer is made of silicon materials, and the piezoelectric assembly is made of silicon materials. The piezoelectric assembly comprises a bottom electrode, a piezoelectric layer and a top electrode which are sequentially stacked in the first direction; the functional layer forms a beam structure, the beam structure extends to the position above the cavity, the elastic layer comprises a suspension part located on the beam structure, and at least one of the bottom electrode and the top electrode comprises an auxiliary structure located on the beam structure; the auxiliary structure comprises a confluence section and at least two branch sections connected to the confluence section, the confluence section and the branch sections are arranged on the suspension part, and the branch sections are arranged at intervals. The utility model is used for at least solving the technical problem that the resonator cannot modulate frequency.

Description

Technical Field

[0001] This utility model relates to the field of semiconductors, and more particularly to a semiconductor device. Background Technology

[0002] Micro-Electro-Mechanical Systems (MEMS) are developed based on semiconductor manufacturing technology. The development of MEMS has promoted the development of wireless communication technology and sensor technology. Today, MEMS resonators are gradually replacing traditional quartz crystal oscillators and becoming the core device of the new generation of frequency references.

[0003] Currently, cantilever beam resonators are used in some resonator structures, which have shown significant advantages in frequency reference sources in the kHz band. However, in actual operation, they cannot be frequency tuned, which hinders the development of communication technology.

[0004] Therefore, how to solve the defect that resonators cannot be frequency tuned is a technical problem that urgently needs to be solved in the industry. Utility Model Content

[0005] This invention provides a semiconductor device to at least solve the technical problem that resonators cannot be frequency tuned.

[0006] To achieve the above objectives, this utility model provides a semiconductor device, comprising: a base layer, an insulating layer, and a functional layer sequentially stacked along a first direction, wherein the insulating layer has a cavity inside, the functional layer includes an elastic layer and a piezoelectric component, the elastic layer is made of silicon material, and the piezoelectric component includes a bottom electrode, a piezoelectric layer, and a top electrode sequentially stacked along the first direction.

[0007] The functional layer forms a beam structure that extends above the cavity, the elastic layer includes a suspended portion located in the beam structure, and at least one of the bottom electrode and the top electrode includes an auxiliary structure located in the beam structure;

[0008] The auxiliary structure includes a merging section and at least two branch sections connected to the merging section. Both the merging section and the branch sections are disposed in the suspended portion, and the branch sections are arranged at intervals. The auxiliary structure is configured to increase the electrostatic force of the piezoelectric component under the action of an electrical signal, so that the piezoelectric component drives the beam structure to vibrate.

[0009] In the semiconductor device provided by this utility model, the elastic layer is made of silicon. The inherent characteristics of silicon determine that the elastic layer has low inherent frequency loss during vibration. Therefore, this application has the effect of reducing energy loss, making the resonator more resistant to mechanical forces, and maintaining performance even under impact and vibration, thereby reducing frequency jumps and significantly improving overall reliability. In addition, since at least one of the bottom electrode and the top electrode includes an auxiliary structure located in the beam structure, the auxiliary structure includes a bus section and at least two branch sections connected to the bus section. Both the bus section and the branch sections are located in the suspended part, which increases the facing area of ​​the bottom electrode and the top electrode and increases the amount of charge stored. By reasonably designing the parameters of the comb-shaped structure and the circuit connection method, precise adjustment of the system's resonant frequency and frequency response characteristics can be achieved.

[0010] In one possible implementation, the functional layer forms a main body that coincides with the projection of the insulating layer along the first direction, the beam structure is a cantilever beam connected to the main body, and the cantilever beam has at least one free end away from the main body.

[0011] In one possible implementation, the auxiliary structure further includes a bottom pad located on the main body, one end of the bus section is connected to the bottom pad, and the other end of the bus section extends to the free end;

[0012] At least two of the branch segments are connected to the same location of the merge segment; and / or each of the branch segments is connected to a different location of the merge segment.

[0013] In one possible implementation, the elastic layer further includes a support portion located in the main body, one end of the suspended portion being connected to the support portion, and the other end of the suspended portion extending to the free end.

[0014] In one possible implementation, one of the bottom electrode and the top electrode includes an auxiliary structure located in the beam structure, and the other of the bottom electrode and the top electrode includes a mating structure;

[0015] The mating structure includes a first top electrode, which includes an extension section and a first top pad. The first top pad is located in the main body, the extension section is located in the beam structure, one end of the extension section is connected to the first top pad, and the other end of the first top electrode extends to the free end.

[0016] In one possible implementation, the piezoelectric layer includes a first portion and a second portion that are interconnected, the first portion being located in the beam structure and the second portion being located in the main body.

[0017] In one possible implementation, the top electrode further includes a second top electrode disposed in the second portion, the second top electrode including a heating section and second top pads connected to both ends of the heating section; at least a portion of the heating section is arranged in a wavy line shape; and / or,

[0018] The top electrode also includes a third top electrode disposed in the second part, the third top electrode being located near the free end, so that the third top electrode is electrically coupled to the extension segment.

[0019] In one possible implementation, the piezoelectric layer is made of a piezoelectric material, which includes aluminum nitride, lithium niobate, zinc oxide; and / or,

[0020] The substrate layer is made of polycrystalline silicon; and / or,

[0021] The insulating layer is made of silicon oxide; and / or,

[0022] The material of the elastic layer includes monocrystalline silicon; and / or,

[0023] The bottom electrode is made of at least one of aluminum, gold, silver, molybdenum, copper, iron, and tungsten; and / or,

[0024] The material of the top electrode includes at least one of aluminum, gold, silver, molybdenum, copper, iron, and tungsten.

[0025] In one possible implementation, the insulating layer is positioned between the base layer and the functional layer, and the cavity is formed by etching on the side of the insulating layer facing away from the base layer.

[0026] In one possible implementation, the cantilever beam is rectangular, and the length L of the cantilever beam and the width H of the cantilever beam satisfy L / H > 10; and / or,

[0027] The width H of the cantilever beam is greater than 20 μm; and / or,

[0028] The thickness T1 of the piezoelectric layer satisfies 500nm ≤ T1 ≤ 2μm; and / or,

[0029] The thickness T2 of the bottom electrode satisfies 100nm ≤ T2 ≤ 500nm; and / or,

[0030] The thickness T3 of the top electrode satisfies 100nm≤T3≤500nm.

[0031] This application utilizes the inverse piezoelectric effect of the piezoelectric layer. In practical applications, an electrical signal needs to be applied to the bottom electrode and the top electrode to generate an alternating electric field between the bottom electrode and the top electrode. Under the action of this alternating electric field, charges are excited inside the piezoelectric layer, causing the piezoelectric layer to deform and resonate with the elastic layer, thus forming mechanical vibration.

[0032] This invention provides a semiconductor device that uses MEMS processing technology to reduce the size of traditional resonant devices and improve the stability of semiconductor devices.

[0033] The present invention provides a semiconductor device in which the top electrode includes a second top electrode and a third top electrode. The second top electrode serves as a heating electrode and the third top electrode serves as a temperature readout electrode, thereby enabling control of the resonator temperature and preventing changes in the resonator frequency due to temperature.

[0034] In addition to the technical problems solved by the embodiments of the present invention, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions as described above, other technical problems that can be solved by a semiconductor device provided by the embodiments of the present invention, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific embodiments. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A three-dimensional structural schematic diagram of a semiconductor device provided in an embodiment of this utility model;

[0037] Figure 2 An exploded view of a semiconductor device provided in an embodiment of this utility model;

[0038] Figure 3 An exploded view of a partial structure of a semiconductor device provided in an embodiment of this utility model;

[0039] Figure 4 A top view of a semiconductor device provided in an embodiment of this utility model;

[0040] Figure 5 for Figure 4 A three-dimensional structural schematic diagram of the cross-sectional view of section AA;

[0041] Figure 6 for Figure 4 A three-dimensional structural schematic diagram of the BB section cross-section;

[0042] Figure 7 for Figure 4 Another three-dimensional structural schematic diagram of the BB section cross-section.

[0043] Explanation of reference numerals in the attached figures:

[0044] 10-Basal layer;

[0045] 20 - Insulation layer;

[0046] 21-Cavity;

[0047] 30 - Elastic layer;

[0048] 31-Suspended part;

[0049] 32-Support section;

[0050] 40 - Bottom electrode;

[0051] 41-Channel segment;

[0052] 42-Branch segment;

[0053] 43 - Bottom pad;

[0054] 50-Piezoelectric layer;

[0055] 51 - Part One;

[0056] 52 - Part Two;

[0057] 60-Top electrode;

[0058] 61 - First top electrode;

[0059] 611-Extension;

[0060] 612 - First top pad;

[0061] 62 - Second top electrode;

[0062] 621 - Heating section;

[0063] 6211 - Broken line segment;

[0064] 6212 - Introduction Section;

[0065] 622 - Second top pad;

[0066] 63 - Third top electrode;

[0067] 631 - Third top pad;

[0068] 70-Beam structure;

[0069] 71-Free end. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0071] Piezoelectric materials can generate an electric field due to mechanical deformation, and can also generate mechanical deformation due to the action of an electric field. A silicon resonator is a device that uses silicon as the resonant body and utilizes the piezoelectric effect of a piezoelectric thin film to generate mechanical vibration when an electric field is applied, thereby generating a resonant frequency.

[0072] The frequency characteristics of silicon resonators are affected by their design structure, material properties, and manufacturing process, resulting in the inability to tune them.

[0073] refer to Figure 1 and Figure 2 As shown, the present invention provides a semiconductor device comprising: a base layer 10, an insulating layer 20 and a functional layer stacked sequentially along a first direction; the insulating layer 20 has a cavity 21 inside; the functional layer includes an elastic layer 30 and a piezoelectric component; the elastic layer 30 is made of silicon material; and the piezoelectric component includes a bottom electrode 40, a piezoelectric layer 50 and a top electrode 60 stacked sequentially along the first direction.

[0074] The functional layer forms a beam structure 70, which extends above the cavity 21. The elastic layer 30 includes a suspended portion 31 located in the beam structure 70. At least one of the bottom electrode 40 and the top electrode 60 includes an auxiliary structure located in the beam structure 70.

[0075] refer to Figure 3 and Figure 4 As shown, the auxiliary structure includes a busbar 41 and at least two branch sections 42 connected to the busbar 41. Both the busbar 41 and the branch sections 42 are disposed in the suspended portion 31, and the branch sections 42 are arranged at intervals. The auxiliary structure is configured to increase the electrostatic force of the piezoelectric component under the action of an electrical signal, so that the piezoelectric component drives the beam structure 70 to vibrate.

[0076] In the semiconductor device provided by this utility model, the elastic layer 30 is made of silicon. The inherent characteristics of silicon determine that the elastic layer has a low inherent frequency loss during vibration. Therefore, this application has the effect of reducing energy loss, making the resonator more resistant to mechanical forces, and maintaining performance even under impact and vibration, thereby reducing frequency jumps and significantly improving overall reliability. In addition, since at least one of the bottom electrode 40 and the top electrode 60 includes an auxiliary structure located in the beam structure 70, the auxiliary structure includes a busbar 41 and at least two branch sections 42 connected to the busbar 41. Both the busbar 41 and the branch sections 42 are disposed in the suspended portion 31, which increases the facing area of ​​the bottom electrode 40 and the top electrode 60, and increases the amount of charge stored. By reasonably designing the parameters of the auxiliary structure and the circuit connection method, precise adjustment of the system's resonant frequency and frequency response characteristics can be achieved.

[0077] In this example, the auxiliary structure has a comb-like shape. The parameters of the auxiliary structure include the number of branch segments 42, the spacing between adjacent branch segments 42, and the arrangement of the branch segments 42. The auxiliary structure effectively increases the sensing area between the bottom electrode 40 and the top electrode 60. This design allows for the generation of a larger electrostatic force when the same voltage is applied, thereby driving the resonator more effectively.

[0078] In one possible implementation, the functional layer forms the main body, which coincides with the projection of the insulating layer 20 along a first direction, and the beam structure 70 is a cantilever beam connected to the main body, the cantilever beam having at least one free end 71 away from the main body.

[0079] In one possible implementation, one of the bottom electrode 40 and the top electrode 60 includes an auxiliary structure located on the beam structure 70, and the other of the bottom electrode 40 and the top electrode 60 includes a mating structure.

[0080] The mating structure includes a first top electrode 61, which includes an extension 611 and a first top pad 612. The first top pad 612 is located in the main body, and the extension 611 is located in the beam structure 70. One end of the extension 611 is connected to the first top pad 612, and the other end of the first top electrode 61 extends to the free end 71.

[0081] Example 1

[0082] In this first embodiment, the bottom electrode 40 includes an auxiliary structure located on the beam structure 70, and the top electrode 60 includes a mating structure.

[0083] Since the bottom electrode 40 includes an auxiliary structure, which includes a bus section 41 and at least two branch sections 42 connected to the bus section 41, and both the bus section 41 and the branch sections 42 are located in the suspended part 31, when the beam structure 70 is in the resonant mode, it helps to increase the charge of the bottom electrode 40, thereby increasing the current output and improving the performance of the resonator.

[0084] In this example, the auxiliary structure is comb-shaped, which enables a uniform distribution of the electric field. In planar electrodes, the electric field may be concentrated or unevenly distributed, resulting in excessively high charge density in some areas and relatively low charge density in others. The comb-shaped geometry of the auxiliary structure guides the electric field to be distributed more evenly on the electrode surface formed by the auxiliary structure, thereby improving charge storage efficiency and stability.

[0085] In this example, the first direction is the thickness direction of the semiconductor device, as referenced. Figure 1 The arrow Z in the diagram indicates the direction.

[0086] In one possible implementation method, refer to Figure 4 As shown, the number of branch segments 42 can be 3, 4 or more, and each branch segment 42 is arranged parallel to each other. The angle between the branch segment 42 and the busbar 41 can be 90°, so that the bottom electrode 40 is comb-shaped. Of course, the angle between the branch segment 42 and the busbar 41 can also be other angles, such as 60°, 45°, etc.

[0087] In one possible implementation, the branch segments 42 are arranged on the same side of the merging segment 41. Alternatively, the branch segments 42 can be arranged on opposite sides of the merging segment 41.

[0088] During production, the spacing and arrangement of the branch segments 42 can be adjusted according to usage requirements.

[0089] When resonance occurs, the piezoelectric component acts as an electromechanical energy transducer, and the suspended portion 31 of the elastic layer 30 becomes the main body of the resonance. Since the elastic layer 30 includes silicon material, the loss of the inherent resonance is reduced, making it easier to obtain a high quality factor.

[0090] In one possible implementation method, refer to Figure 1 and Figure 2 As shown, cavity 21 is connected to the external environment. The cross-sectional shape of cavity 21 includes, but is not limited to, rectangular, circular, elliptical, and rhomboid shapes. The depth of cavity 21 is greater than half the amplitude of beam structure 70 to prevent the bottom of cavity 21 from interfering with the vibration of beam structure 70 and to ensure the effectiveness of use.

[0091] In one possible implementation, the insulating layer 20 may be grown on the surface of the substrate layer 10, for example by a chemical vapor deposition growth method.

[0092] In one possible implementation, the side of the insulating layer 20 facing away from the base layer 10 is the top surface, and the cavity 21 can extend from the top surface of the insulating layer 20 through the bottom surface of the insulating layer 20, i.e., the cavity 21 is a through hole. Of course, the bottom of the cavity 21 can also be located between the top and bottom surfaces of the insulating layer 20, i.e., the depth of the cavity 21 is less than the thickness of the insulating layer 20, and the cavity 21 is a blind hole.

[0093] In one possible implementation, the piezoelectric component further includes a piezoelectric layer 50 and a top electrode 60, with the bottom electrode 40, piezoelectric layer 50 and top electrode 60 stacked sequentially, and the bottom electrode 40 disposed on the side of the elastic layer 30 facing away from the insulating layer 20.

[0094] When piezoelectric materials are subjected to external vibration, they deform, causing changes in internal stress and resulting in polarization. Opposite charges appear on the two opposing surfaces of the piezoelectric material, generating an electric field. This polarization caused by deformation is called the direct piezoelectric effect, which is essentially the conversion of mechanical energy into electrical energy. When a piezoelectric material is subjected to an electric field, it produces strain in a certain direction, and the electric field strength has a linear relationship with the strain; this is called the inverse piezoelectric effect. In the piezoelectric effect, mechanical energy and electrical energy can be interconverted.

[0095] This application utilizes the inverse piezoelectric effect of the piezoelectric layer 50. In practical applications, an electrical signal needs to be applied to the bottom electrode 40 and the top electrode 60 to generate an alternating electric field between the bottom electrode 40 and the top electrode 60. Under the action of this alternating electric field, charges are excited inside the piezoelectric layer 50, causing the piezoelectric layer 50 to deform and resonate with the elastic layer 30, thus forming mechanical vibration.

[0096] The present invention provides a semiconductor device in which the bottom electrode 40 is patterned and designed as a comb-like structure, and the top electrode 60 is coupled to the bottom electrode 40. The frequency can be adjusted and controlled by changing the voltage applied between the top electrode 60 and the bottom electrode 40.

[0097] The reason why the bottom electrode 40 is designed with a comb-like structure to achieve frequency adjustment is mainly because the increased area of ​​the positive and negative electrodes allows for a larger amount of stored charge. By rationally designing the parameters and circuit connections of the comb-like structure, precise adjustment of the system's resonant frequency and frequency response characteristics can be achieved. The comb-like structure of the bottom electrode 40, with its comb-shaped electrode arrangement, helps optimize the electric field distribution, making the electric field force between the top electrode 60 and the bottom electrode 40 act more uniformly and concentratedly on the elastic layer 30. This uniform electric field distribution helps reduce energy loss and improve driving efficiency.

[0098] In one possible implementation method, refer to Figure 1 and Figure 6 As shown, beam structure 70 is a cantilever beam connected to the main body. The cantilever beam has at least one free end 71 located away from the main body. The free end 71 is not connected to the main body. The vibration amplitude at the free end 71 in beam structure 70 is relatively large, which is beneficial for the beam structure 70 to vibrate and improves its vibration sensitivity.

[0099] In one possible implementation, the cantilever beam is rectangular, with one end connected to the main body and the other end being a free end 71 away from the main body.

[0100] In another possible implementation, the cantilever beam can also be cross-shaped, with both ends of the cantilever beam connected to the main body and the other two ends of the cantilever beam forming free ends 71.

[0101] In one possible implementation method, refer to Figure 1 , Figure 4 and Figure 7 As shown, the elastic layer 30 includes a suspended portion 31 located in the beam structure 70 and a supporting portion 32 located in the main body. One end of the suspended portion 31 is connected to the supporting portion 32, and the other end of the suspended portion 31 extends to the free end 71. The supporting portion 32 is stably supported by the insulating layer 20, and there is a gap between the suspended portion 31 and the inner bottom wall of the cavity 21, so that the suspended portion 31 is suspended in the cavity 21, thereby allowing the beam structure 70 to vibrate freely.

[0102] In one possible implementation method, refer to Figure 1 and Figure 4 As shown, the auxiliary structure also includes a bottom pad 43 located in the main body, one end of the bus section 41 is connected to the bottom pad 43, and the other end of the bus section 41 extends to the free end 71.

[0103] In one possible implementation, at least two branch segments 42 are connected to the same location of the busbar 41, such that at least a portion of the bottom electrode 40 is interdigitated, and the branch segments 42 connected to the same location of the busbar 41 have an included angle.

[0104] In one possible implementation, each branch segment 42 is connected to a different location on the confluence segment 41.

[0105] In one possible implementation, some branch segments 42 are connected to the same location on the merging segment 41, while the remaining branch segments 42 are connected to different locations on the merging segment 41. In this example, the number of branch segments 42 is not specifically limited here. There may be at least one group of branch segments 42, and each group may contain one, two, three, or more branch segments 42. The branch segments 42 in each group are arranged at intervals on one or both sides of the merging segment 41.

[0106] In one possible implementation, the merging segment 41 can be strip-shaped, and the branch segments 42 can be strip-shaped. The lengths of the branch segments 42 can be the same or different. The branch segments 42 can be arranged parallel to each other with consistent spacing.

[0107] In one possible implementation method, refer to Figure 1 and Figure 5 As shown, the top electrode 60 includes a mating structure, which includes a first top electrode 61. The first top electrode 61 includes an extension 611 and a first top pad 612. The first top pad 612 is located in the main body, and the extension 611 is located in the beam structure 70. One end of the extension 611 is connected to the first top pad 612, and the other end of the first top electrode 61 extends to the free end 71.

[0108] The bottom pad 43 and the first top pad 612 serve as input or output ports for external electrical signals. Under the action of external voltage excitation, the functional layer generates a stable frequency signal.

[0109] In one possible implementation, the extension 611 at least partially overlaps with the projection of the busbar 41 along the first direction, which helps to improve the coupling between the bottom electrode 40 and the top electrode 60.

[0110] In one possible implementation, the extension 611 is strip-shaped and integrally connected to the first top pad 612.

[0111] In one possible implementation, the piezoelectric layer 50 includes a first portion 51 and a second portion 52 that are interconnected. The first portion 51 is located in the beam structure 70, and the second portion 52 is located in the main body. Along a first direction, the projection of the second portion 52 coincides with that of the support portion 32.

[0112] In one possible implementation, the top electrode 60 further includes a second top electrode 62 disposed in the second portion 52, the second top electrode 62 including a heating section 621 and a second top pad 622 connected to both ends of the heating section 621; at least a portion of the heating section 621 is arranged in a wavy line shape.

[0113] Because the second top electrode 62 has its own impedance, it becomes a heating electrode. At least a portion of the heating section 621 is arranged in a wavy pattern, which increases the area of ​​the heating section 621 and improves its heating effect after the second top electrode 62 is energized. The two second top pads 622 at both ends of the heating section 621 also serve as input or output ports for external electrical signals.

[0114] In one possible implementation, the heating section 621 is a metal wire, comprising an interconnected zigzag section 6211 and a lead-out section 6212. One end of the zigzag section 6211 is connected to a second top pad 622, and the other end of the zigzag section 6211 is connected to the lead-out section 6212. The end of the lead-out section 6212 opposite to the zigzag section 6211 is also connected to a second top pad 622. The zigzag section 6211 can be serpentine or wavy, increasing the arrangement area of ​​the second top electrode 62 and improving its heating effect. The lead-out section 6212 can be straight.

[0115] In one possible implementation, the top electrode 60 further includes a third top electrode 63 disposed on the second portion 52, located near the free end 71, so that the third top electrode 63 is electrically coupled to the extension 611. The third top electrode 63 serves as a temperature readout electrode, facilitating control of the resonator temperature and preventing changes in the resonator frequency due to temperature influences. The third top electrode 63 has third top pads 631 at both ends, which serve as input or output ports for electrical signals.

[0116] In one possible implementation, the piezoelectric layer 50 is made of a piezoelectric material, including aluminum nitride (AlN), lithium niobate (LiNbO3), and zinc oxide (ZnO). The piezoelectric layer 50 can be deposited on the bottom electrode 40 using processes such as single-crystal slicing, metal-organic chemical vapor deposition (MOCVD), and physical vapor deposition (PVD).

[0117] When piezoelectric materials are subjected to external vibration, they deform, causing changes in internal stress and resulting in polarization. Opposite charges appear on the two opposing surfaces of the piezoelectric material, generating an electric field. This polarization caused by deformation is called the direct piezoelectric effect, which is essentially the conversion of mechanical energy into electrical energy. When a piezoelectric material is subjected to an electric field, it produces strain in a certain direction, and the electric field strength has a linear relationship with the strain; this is called the inverse piezoelectric effect. In the piezoelectric effect, mechanical energy and electrical energy can be interconverted.

[0118] This application utilizes the inverse piezoelectric effect. By applying a voltage to the piezoelectric material, stress is generated in the piezoelectric layer 50, causing strain in a certain direction. The first part 51 of the piezoelectric layer 50 also causes the suspended part 31 to vibrate. When the excitation frequency that causes the first part 51 of the piezoelectric layer 50 to vibrate is close to the resonant frequency, resonance will occur. The regular deformation in this state is called the resonant mode. At the same time, the first part 51 of the piezoelectric layer 50 will also deform due to the vibration of the suspended part 31. Therefore, the first part 51 of the piezoelectric layer 50 generates moving charges. The charges can be collected on the top electrode 60 to form a current output, which serves to detect the temperature and prevent the resonator frequency from changing due to temperature.

[0119] In one possible implementation, the substrate 10 is made of polycrystalline silicon and serves as a support layer for the resonator. The substrate 10 may also be made of one or more materials such as monocrystalline silicon, sapphire, or silicon carbide.

[0120] In one possible implementation, the insulating layer 20 is made of a silicon oxide material, such as silicon dioxide. The selective corrosion of the silicon oxide material by a corrosive liquid or gas can be used to remove part of the insulating layer 20, forming an opening 21 inside the insulating layer 20 facing away from the base layer 10. This allows the lower part of the beam structure 70 to vibrate.

[0121] In one possible implementation, the material of the elastic layer 30 includes monocrystalline silicon.

[0122] In this example, since the material of the substrate 10 includes polycrystalline silicon and the material of the elastic layer 30 includes monocrystalline silicon, the size of the resonator can be significantly reduced compared to a resonator that uses a quartz crystal resonator as the sensitive element, which is beneficial for integrated development.

[0123] The present invention provides a semiconductor device in which the application of silicon material enables the resonator to have advantages such as frequency stability, low insertion loss, high quality factor, and strong anti-interference ability.

[0124] In one possible implementation, the material of the bottom electrode 40 includes at least one of aluminum, gold, silver, molybdenum, copper, iron, and tungsten;

[0125] In one possible implementation, the material of the top electrode 60 includes at least one of aluminum, gold, silver, molybdenum, copper, iron, and tungsten.

[0126] In one possible implementation, the insulating layer 20 is positioned between the substrate layer 10 and the functional layer, and the side of the insulating layer 20 facing away from the substrate layer 10 is etched to form a cavity 21.

[0127] In one possible implementation, a portion of the material at the center of the side of the insulating layer 20 facing away from the substrate 10 is removed by a hydrofluoric acid etching process, forming a recessed cavity 21 at the center of the insulating layer 20.

[0128] In one possible implementation, the bottom pad 43 has a length and width of 100 μm, the first top pad 612 has a length and width of 100 μm, and the second top pad 622 has a length and width of 100 μm.

[0129] In one possible implementation method, refer to Figure 5 As shown, the cantilever beam is rectangular, and the length L and width H of the cantilever beam satisfy L / H>10, so that the cantilever beam has sufficient length to ensure the vibration effect of the cantilever beam.

[0130] In one possible implementation, the width H of the cantilever beam is greater than 20 μm. For example, the width H of the cantilever beam can be 20 μm, 30 μm, 40 μm, or 50 μm, etc.

[0131] In one possible implementation, the thickness T1 of the piezoelectric layer 50 satisfies 500nm ≤ T1 ≤ 2μm. For example, the thickness T1 of the piezoelectric layer 50 can be 100nm, 200nm, 300nm, 400nm, or 500nm, etc.

[0132] In one possible implementation, the thickness T2 of the bottom electrode 40 satisfies 100nm ≤ T2 ≤ 500nm. For example, the thickness T2 of the bottom electrode 40 can be 100nm, 200nm, 300nm, 400nm, or 500nm, etc.

[0133] In one possible implementation, the thickness T3 of the top electrode 60 satisfies 100nm ≤ T3 ≤ 500nm. For example, the thickness T3 of the top electrode 60 can be 100nm, 200nm, 300nm, 400nm, or 500nm, etc.

[0134] The resonant frequency of the resonator can be adjusted by adjusting the thickness T1 of the piezoelectric layer 50, the thickness T2 of the bottom electrode 40, and the thickness T3 of the top electrode 60.

[0135] In one possible implementation, the thickness of the substrate 10 is 700 μm or 2 μm, the thickness of the insulating layer 20 is 2 μm, the width of the bus section 41 is between 10 μm and 20 μm, and the width of the extension section 611 is between 10 μm and 20 μm.

[0136] The present invention provides a semiconductor device that provides a driving voltage to a piezoelectric layer 50 through a circuit module and obtains a resonant frequency. The circuit module is electrically connected to the display module, which is used to display temperature information, that is, to display the temperature corresponding to the vibration frequency. The display module can be, for example, a display screen.

[0137] This invention provides a semiconductor device that uses MEMS processing technology to reduce the size of traditional resonant devices and improve the stability of semiconductor devices.

[0138] The present invention provides a semiconductor device in which the top electrode 60 includes a second top electrode 62 and a third top electrode 63. The second top electrode 62 serves as a heating electrode and the third top electrode 63 serves as a temperature readout electrode, thereby enabling control of the resonator temperature and preventing changes in the resonator frequency due to temperature.

[0139] The semiconductor device provided by this utility model is a silicon MEMS resonator, which has a high degree of integration and can be integrated into a multi-chip module. The silicon MEMS resonator can be packaged with other silicon chips, reducing integration difficulty and effectively reducing costs. For example, it can be embedded in a modem in a transceiver or used as a real-time clock in a microcontroller. It can stably generate high-precision signal waveforms, provide a reliable clock reference for external circuits, reduce the dependence of semiconductor devices on external systems, and promote the development of the communications industry towards higher integration and higher efficiency.

[0140] Example 2

[0141] The difference between this second embodiment and the first embodiment is that, in this second embodiment, the bottom electrode 40 includes a mating structure, and the top electrode 60 includes an auxiliary structure located on the beam structure 70. One of the bottom electrode 40 and the top electrode 60 is a positive electrode, and the other is a negative electrode.

[0142] In this example, the auxiliary structure is designed as a comb-like structure. The reason why frequency adjustment can be achieved is mainly because the increased area of ​​the positive and negative electrodes allows for a larger amount of stored charge. By properly designing the parameters of the comb-like structure and the circuit connection method, precise adjustment of the system's resonant frequency and frequency response characteristics can be achieved.

[0143] Example 3

[0144] The difference between this embodiment and embodiment one is that in this embodiment, the bottom electrode 40 includes an auxiliary structure located on the beam structure 70, and the top electrode 60 also includes an auxiliary structure located on the beam structure 70. Neither the bottom electrode 40 nor the top electrode 60 includes the aforementioned mating structure. One of the bottom electrode 40 and the top electrode 60 is a positive electrode, and the other is a negative electrode.

[0145] In this example, the auxiliary structure is designed as a comb-like structure. The reason why frequency adjustment can be achieved is mainly because the increased area of ​​the positive and negative electrodes allows for a larger amount of stored charge. By properly designing the parameters of the comb-like structure and the circuit connection method, precise adjustment of the system's resonant frequency and frequency response characteristics can be achieved.

[0146] It should be noted that the numerical values ​​and ranges involved in this application are approximate values. Due to the influence of the manufacturing process, there may be a certain range of errors, which can be considered negligible by those skilled in the art.

[0147] In the description of this utility model, it should be understood that the terms "center", "length", "width", "thickness", "top", "bottom", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", "axial", "circumferential", etc., used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the indicated position or component must have a specific orientation, or a specific structure and operation, and therefore should not be construed as a limitation of this utility model.

[0148] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0149] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0150] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A semiconductor device, characterized in that, include: A base layer (10), an insulating layer (20), and a functional layer are stacked sequentially along a first direction. The insulating layer (20) has a cavity (21) inside. The functional layer includes an elastic layer (30) and a piezoelectric component. The elastic layer (30) is made of silicon material. The piezoelectric component includes a bottom electrode (40), a piezoelectric layer (50), and a top electrode (60) stacked sequentially along the first direction. The functional layer forms a beam structure (70) that extends above the cavity (21), the elastic layer (30) includes a suspended portion (31) located in the beam structure (70), and at least one of the bottom electrode (40) and the top electrode (60) includes an auxiliary structure located in the beam structure (70). The auxiliary structure includes a busbar (41) and at least two branch sections (42) connected to the busbar (41). The busbar (41) and the branch sections (42) are both located in the suspended portion (31), and the branch sections (42) are arranged at intervals. The auxiliary structure is configured to increase the electrostatic force of the piezoelectric component under the action of an electrical signal, so that the piezoelectric component drives the beam structure (70) to vibrate.

2. The semiconductor device according to claim 1, characterized in that, The functional layer forms the main body, the main body coincides with the projection of the insulating layer (20) along the first direction, the beam structure (70) is a cantilever beam, the cantilever beam is connected to the main body, and the cantilever beam has at least one free end (71) away from the main body.

3. The semiconductor device according to claim 2, characterized in that, The auxiliary structure also includes a bottom pad (43) located in the main body, one end of the bus section (41) is connected to the bottom pad (43), and the other end of the bus section (41) extends to the free end (71). At least two of the branch segments (42) are connected to the same location of the confluence segment (41); and / or each of the branch segments (42) is connected to a different location of the confluence segment (41).

4. The semiconductor device according to claim 2, characterized in that, The elastic layer (30) also includes a support portion (32) located in the main body, one end of the suspended portion (31) is connected to the support portion (32), and the other end of the suspended portion (31) extends to the free end (71).

5. The semiconductor device according to any one of claims 2-4, characterized in that, One of the bottom electrode (40) and the top electrode (60) includes an auxiliary structure located in the beam structure (70), and the other of the bottom electrode (40) and the top electrode (60) includes a mating structure; The mating structure includes a first top electrode (61), the first top electrode (61) includes an extension (611) and a first top pad (612), the first top pad (612) is located in the main body, the extension (611) is located in the beam structure (70), one end of the extension (611) is connected to the first top pad (612), and the other end of the first top electrode (61) extends to the free end (71).

6. The semiconductor device according to claim 5, characterized in that, The piezoelectric layer (50) includes a first part (51) and a second part (52) that are connected to each other. The first part (51) is located in the beam structure (70), and the second part (52) is located in the main body.

7. The semiconductor device according to claim 6, characterized in that, The top electrode (60) further includes a second top electrode (62) disposed in the second portion (52), the second top electrode (62) including a heating section (621) and second top pads (622) connected to both ends of the heating section (621); at least a portion of the heating section (621) is arranged in a wavy line shape; and / or, The top electrode (60) further includes a third top electrode (63) disposed in the second part (52), the third top electrode (63) being located near the free end (71) so that the third top electrode (63) is electrically coupled to the extension (611).

8. The semiconductor device according to any one of claims 1-3, characterized in that, The insulating layer (20) is separated between the base layer (10) and the functional layer, and the cavity (21) is formed by etching on the side of the insulating layer (20) facing away from the base layer (10).

9. The semiconductor device according to claim 2, characterized in that, The cantilever beam is rectangular, and the length L and width H of the cantilever beam satisfy L / H > 10; and / or, The width H of the cantilever beam is greater than 20 μm; and / or, The thickness T1 of the piezoelectric layer (50) satisfies 500nm ≤ T1 ≤ 2μm; and / or, The thickness T2 of the bottom electrode (40) satisfies 100nm ≤ T2 ≤ 500nm; and / or, The thickness T3 of the top electrode (60) satisfies 100nm≤T3≤500nm.

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