Semiconductor device

Abstract

The invention provides a semiconductor device which comprises a substrate layer, an insulating layer and a functional layer which are sequentially stacked in the first direction, a cavity is formed in the insulating layer, the functional layer comprises an elastic layer and a piezoelectric assembly, the elastic layer is made of a silicon material, and the piezoelectric assembly is made of a silicon material. 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 invention is used for at least solving the technical problem that the resonator cannot modulate frequency.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a semiconductor device. Background Art

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

[0003] At present, in the structure of some resonators, cantilever beam resonators are used, which show significant advantages in the frequency reference source of the KHz frequency band. However, in actual operation, there is a problem of inability to adjust the frequency, which hinders the development of communication technology.

[0004] Therefore, how to solve the defect that the resonator cannot adjust the frequency is a technical problem that needs to be solved urgently in the industry. Summary of the invention

[0005] The present invention provides a semiconductor device, which is used to at least solve the technical problem that the resonator cannot be frequency modulated.

[0006] In order to achieve the above object, the present invention provides a semiconductor device, comprising: a substrate layer, an insulating layer and a functional layer stacked in sequence along a first direction, wherein the insulating layer has a cavity inside, the functional layer comprises an elastic layer and a piezoelectric component, the elastic layer is a silicon material, and the piezoelectric component comprises a bottom electrode, a piezoelectric layer and a top electrode stacked in sequence along the first direction;

[0007] The functional layer forms a beam structure, the beam structure 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 bus section and at least two branch sections connected to the bus section. The bus section and the branch sections are both arranged in the suspended portion, and the branch sections are arranged at intervals from each other. 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 a semiconductor device provided by the present invention, the elastic layer is made of silicon material. The characteristics of the silicon material itself determine that the natural frequency loss of the vibration of the elastic layer is low. Therefore, the present application has the effect of reducing energy loss, and the resonator is more resistant to mechanical force. Even in the case of impact and vibration, it can maintain performance, thereby reducing frequency jumps and greatly 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, and the bus section and the branch section are both arranged in the suspended portion, the facing area of ​​the bottom electrode and the top electrode is increased, and the amount of stored charge becomes larger. By reasonably designing the parameters of the comb-shaped structure and the circuit connection method, it is possible to achieve precise adjustment of the system resonant frequency and frequency response characteristics.

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

[0011] In a 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 position of the confluence segment; and / or, the branch segments are respectively connected to different positions of the confluence segment.

[0013] In a possible implementation, the elastic layer further includes a supporting portion located on the main body, one end of the suspended portion is connected to the supporting portion, and the other end of the suspended portion extends to the free end.

[0014] In a 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 matching structure;

[0015] The matching structure includes a first top electrode, which includes an extension section and a first top pad, wherein 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 a possible implementation, the piezoelectric layer includes a first part and a second part that are connected to each other, the first part is located in the beam structure, and the second part is located in the main body.

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

[0018] The top electrode further includes a third top electrode disposed on the second portion, and the third top electrode is located close to the free end so that the third top electrode is electrically coupled to the extension segment by induction.

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

[0020] The material of the base layer includes polysilicon material; and / or,

[0021] The material of the insulating layer includes silicon oxide material; and / or,

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

[0023] The material of the bottom electrode includes 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 a possible implementation, the insulating layer is separated between the base layer and the functional layer, and the cavity is formed by etching a surface of the insulating layer that is opposite to the base layer.

[0026] In a 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] The present invention utilizes the inverse piezoelectric effect of the piezoelectric layer. In actual application, it is necessary to apply electric signals to the bottom electrode and the top electrode to generate an AC electric field between the bottom electrode and the top electrode. Under the action of the AC electric field, charges are excited inside the piezoelectric layer, the piezoelectric layer is deformed, and resonates with the elastic layer to form mechanical vibrations.

[0032] The invention provides a semiconductor device which uses a MEMS process to reduce the volume of a traditional resonant device and improve the stability of the semiconductor device.

[0033] A semiconductor device provided by the present invention has a top electrode including a second top electrode and a third top electrode, wherein the second top electrode is used as a heating electrode and the third top electrode is used as a temperature reading electrode, thereby realizing control of the temperature of the resonator and preventing the resonator frequency from changing due to the influence of temperature.

[0034] In addition to the technical problems solved by the embodiments of the present invention described above, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of the technical solutions, other technical problems that can be solved by a semiconductor device provided by an embodiment 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 implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic diagram of the three-dimensional structure of a semiconductor device provided by an embodiment of the present invention;

[0037] Figure 2 An exploded diagram of a semiconductor device provided by an embodiment of the present invention;

[0038] Figure 3 An exploded view of a local structure of a semiconductor device provided by an embodiment of the present invention;

[0039] Figure 4 A top view of a semiconductor device provided by an embodiment of the present invention;

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

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

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

[0043] Description of reference numerals:

[0044] 10 - basal layer;

[0045] 20-insulating layer;

[0046] 21 - cavity;

[0047] 30- elastic layer;

[0048] 31- suspended part;

[0049] 32-supporting part;

[0050] 40- bottom electrode;

[0051] 41-Confluence section;

[0052] 42-branch segment;

[0053] 43- bottom pad;

[0054] 50- piezoelectric layer;

[0055] 51-Part I;

[0056] 52-Part II;

[0057] 60-top electrode;

[0058] 61- first top electrode;

[0059] 611-Extension;

[0060] 612-first top pad;

[0061] 62- a second top electrode;

[0062] 621-heating section;

[0063] 6211-broken line segment;

[0064] 6212-lead-out 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 DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] Piezoelectric materials can generate electric fields due to mechanical deformation, and can also generate mechanical deformation due to electric fields. Silicon resonator is a kind of resonant body with silicon as the resonant body. It uses the piezoelectric effect of piezoelectric 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, and there is a problem that they cannot be frequency-modulated.

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

[0074] The functional layer forms a beam structure 70, the beam structure 70 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;

[0075] refer to Figure 3 and Figure 4 As shown, the auxiliary structure includes a bus section 41 and at least two branch sections 42 connected to the bus section 41. The bus section 41 and the branch sections 42 are both arranged on the suspended portion 31, and the branch sections 42 are arranged at intervals from each other. The auxiliary structure is configured to enhance 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 a semiconductor device provided by the present invention, the elastic layer 30 is made of silicon material. The characteristics of the silicon material itself determine that the natural frequency loss of the elastic layer vibration is low. Therefore, the present application has the effect of reducing energy loss, and the resonator is more resistant to mechanical force. Even in the case of impact and vibration, it can maintain performance, thereby reducing frequency jumps and greatly 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 bus section 41 and at least two branch sections 42 connected to the bus section 41, and the bus section 41 and the branch section 42 are both arranged in the suspended portion 31, the facing area of ​​the bottom electrode 40 and the top electrode 60 is increased, and the amount of stored charge becomes larger. By reasonably designing the parameters of the auxiliary structure and the circuit connection method, the system resonant frequency and frequency response characteristics can be accurately adjusted.

[0077] In this example, the auxiliary structure is a comb-tooth structure, and the parameters of the auxiliary structure include the number of branch segments 42, the spacing between two adjacent branch segments 42, the arrangement position of the branch segments 42, etc. The auxiliary structure effectively increases the sensing area between the bottom electrode 40 and the top electrode 60. This design enables a greater electrostatic force to be generated when the same voltage is applied, thereby driving the resonator more effectively.

[0078] In one possible implementation, the functional layer forms a 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.

[0079] In one possible implementation, 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 matching structure;

[0080] The matching structure includes a first top electrode 61, which includes an extension section 611 and a first top pad 612. The first top pad 612 is located in the main body, the extension section 611 is located in the beam structure 70, one end of the extension section 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] Embodiment 1

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

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

[0084] In this example, the auxiliary structure is in the shape of comb teeth, which can achieve uniform distribution of the electric field. In a planar electrode, the electric field may be more concentrated or unevenly distributed, resulting in excessively high charge density in some areas and relatively low charge density in other areas. The auxiliary structure can guide the electric field to be more evenly distributed on the electrode surface formed by the auxiliary structure through its comb-tooth geometry, thereby improving the storage efficiency and stability of the charge.

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

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

[0087] In a possible implementation, each branch segment 42 is arranged on the same side of the converging segment 41 . Alternatively, each branch segment 42 is arranged on two opposite sides of the converging 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 plays the role of electromechanical 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, so it is easier to obtain a high quality factor.

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

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

[0092] In a possible implementation, the side of the insulating layer 20 facing away from the base layer 10 is the top surface, and the cavity 21 may be a through hole extending from the top surface of the insulating layer 20 to the bottom surface of the insulating layer 20. Of course, the bottom of the cavity 21 may also be located between the top surface and the bottom surface of the insulating layer 20, that is, 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 a possible implementation, the piezoelectric component further includes a piezoelectric layer 50 and a top electrode 60 . The bottom electrode 40 , the piezoelectric layer 50 and the top electrode 60 are stacked in sequence, and the bottom electrode 40 is disposed on a side of the elastic layer 30 that is opposite to the insulating layer 20 .

[0094] When a piezoelectric material is deformed under the influence of external vibration, the stress inside the piezoelectric material changes, polarization occurs inside the piezoelectric material, and opposite positive and negative charges appear on the two opposite surfaces of the piezoelectric material, thus generating an electric field. This phenomenon of polarization due to deformation is called the positive piezoelectric effect, which is essentially the process of converting mechanical energy into electrical energy. When a piezoelectric material is subjected to an electric field, strain is generated in a certain direction, and there is a linear relationship between the electric field strength and the strain, which is called the inverse piezoelectric effect. In the piezoelectric effect, mechanical energy and electrical energy can be converted into each other.

[0095] The present application utilizes the inverse piezoelectric effect of the piezoelectric layer 50. In actual application, it is necessary to apply an electric signal to the bottom electrode 40 and the top electrode 60, so as to generate an AC electric field between the bottom electrode 40 and the top electrode 60. Under the action of the AC electric field, electric charges are excited inside the piezoelectric layer 50, the piezoelectric layer 50 is deformed, and resonates with the elastic layer 30 to form mechanical vibrations.

[0096] The present invention provides a semiconductor device, which patterns the bottom electrode 40 and designs the bottom electrode 40 into a comb-tooth structure, and couples the top electrode 60 with 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 as a comb-tooth structure can achieve frequency adjustment is mainly because the area of ​​the positive and negative electrodes facing each other increases, and the amount of stored charge increases. By reasonably designing the parameters of the comb-tooth structure and the circuit connection method, the system resonant frequency and frequency response characteristics can be accurately adjusted. The bottom electrode 40 is designed as a comb-tooth structure. The arrangement of the comb-tooth-shaped electrodes helps to optimize the electric field distribution, so that the electric field force between the top electrode 60 and the bottom electrode 40 acts more evenly and concentratedly on the elastic layer 30. This uniform electric field distribution helps to reduce energy loss and improve driving efficiency.

[0098] In one possible implementation, reference Figure 1 and Figure 6 As shown, the beam structure 70 is a cantilever beam, which is connected to the main body and has at least one free end 71 away from the main body. The free end 71 is not connected to the main body, and the vibration amplitude at the position of the free end 71 in the beam structure 70 is large, which is conducive to the vibration of the beam structure 70 and improves the sensitivity of the vibration.

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

[0100] In another possible implementation, the cantilever beam may also be in a cross shape, 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, reference 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, so that the beam structure 70 can vibrate freely.

[0102] In one possible implementation, reference Figure 1 and Figure 4 As shown, the auxiliary structure further 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 position of the bus segment 41 , so that at least part of the bottom electrode 40 is in a forked finger shape, and there is an angle between the branch segments 42 connected to the same position of the bus segment 41 .

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

[0105] In a possible implementation, some of the branch segments 42 are connected to the same position of the confluence segment 41, and the remaining branch segments 42 are respectively connected to different positions of the confluence segment 41. In this example, the number of the branch segments 42 is not specifically limited here, and the branch segments 42 may be at least one group, and in each group, the number of the branch segments 42 may be 1, 2, 3 or more, and each group of branch segments 42 is arranged at intervals on one side or both sides of the confluence segment 41.

[0106] In a possible implementation, the confluence section 41 may be in a strip shape, the branch sections 42 may be in a strip shape, the lengths of the branch sections 42 may be the same or different, and the branch sections 42 may be arranged parallel to each other with the same spacing therebetween.

[0107] In one possible implementation, reference Figure 1 and Figure 5 As shown, the top electrode 60 includes a matching structure, which includes a first top electrode 61. The first top electrode 61 includes an extension section 611 and a first top pad 612. The first top pad 612 is located in the main body, and the extension section 611 is located in the beam structure 70. One end of the extension section 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 access ports or output ports for external electrical signals. Under the action of external voltage excitation, the functional layer generates a stable frequency signal.

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

[0110] In a possible implementation, the extension section 611 is in a strip shape, and the extension section 611 is integrally connected to the first top pad 612 .

[0111] In one possible implementation, the piezoelectric layer 50 includes a first part 51 and a second part 52 connected to each other, the first part 51 is located in the beam structure 70, the second part 52 is located in the main body, and along the first direction, the second part 52 coincides with the projection of the support part 32.

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

[0113] Since the second top electrode 62 itself has impedance, the second top electrode 62 becomes a heating electrode. At least part of the heating segment 621 is arranged in a wavy line shape, which can increase the arrangement area of ​​the heating segment 621. After the second top electrode 62 is energized, the heating effect of the second top electrode 62 can be improved. The two second top pads 622 at both ends of the heating segment 621 also serve as access ports or output ports for external electrical signals.

[0114] In a possible implementation, the heating segment 621 is a metal wire, and the heating segment 621 includes a folded line segment 6211 and a lead-out segment 6212 connected to each other, one end of the folded line segment 6211 is connected to a second top pad 622, the other end of the folded line segment 6211 is connected to the lead-out segment 6212, and the end of the lead-out segment 6212 opposite to the folded line segment 6211 is connected to another second top pad 622, wherein the folded line segment 6211 may be serpentine or wavy, which increases the arrangement area of ​​the second top electrode 62 and improves the heating effect of the second top electrode 62. The lead-out segment 6212 may be straight.

[0115] In a possible implementation, the top electrode 60 further includes a third top electrode 63 disposed on the second portion 52, and the third top electrode 63 is located near the free end 71, so that the third top electrode 63 and the extension section 611 are electrically coupled and induced. The third top electrode 63 becomes a temperature readout electrode, which facilitates the control of the resonator temperature and prevents the resonator frequency from changing due to the influence of temperature. The third top electrode 63 has third top pads 631 at both ends, and the two third top pads 631 serve as access ports or output ports for electrical signals.

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

[0117] When a piezoelectric material is deformed under the influence of external vibration, the stress inside the piezoelectric material changes, polarization occurs inside the piezoelectric material, and opposite positive and negative charges appear on the two opposite surfaces of the piezoelectric material, thus generating an electric field. This phenomenon of polarization due to deformation is called the positive piezoelectric effect, which is essentially the process of converting mechanical energy into electrical energy. When a piezoelectric material is subjected to an electric field, strain is generated in a certain direction, and there is a linear relationship between the electric field strength and the strain, which is called the inverse piezoelectric effect. In the piezoelectric effect, mechanical energy and electrical energy can be converted into each other.

[0118] The present application utilizes the inverse piezoelectric effect. By applying voltage to the piezoelectric material, stress is generated in the piezoelectric layer 50. The piezoelectric layer 50 generates strain in a certain direction, and the first part 51 of the piezoelectric layer 50 drives the suspended part 31 to vibrate. When the excitation frequency of the first part 51 of the piezoelectric layer 50 to generate vibration is close to the resonant frequency, resonance will occur. The regular deformation in this state is called a resonant mode. At the same time, the first part 51 of the piezoelectric layer 50 will also be deformed 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 plays a role in detecting temperature and preventing the resonator frequency from changing due to the influence of temperature.

[0119] In a possible implementation, the material of the base layer 10 includes polycrystalline silicon material, and the base layer 10 is a support layer of the resonator. The material of the base layer 10 may also include one or more of single crystal silicon, sapphire or silicon carbide.

[0120] In one possible implementation, the material of the insulating layer 20 includes a silicon oxide material, such as silicon dioxide, and the selective corrosion of the silicon oxide material by corrosive liquid or gas can be utilized to facilitate the removal of a portion of the insulating layer 20, thereby forming a cavity 21 inside the insulating layer 20 with an opening facing away from the base layer 10, so that the bottom of the beam structure 70 is not supported, thereby achieving vibration of the beam structure 70.

[0121] In a possible implementation, the material of the elastic layer 30 includes single crystal silicon material.

[0122] In this example, since the material of the base layer 10 includes polysilicon material and the material of the elastic layer 30 includes single crystal silicon material, the size of the resonator can be greatly reduced compared to a resonator using a quartz crystal resonator as a sensitive element, which is conducive to the development of integration.

[0123] The present invention provides a semiconductor device, in which the application of silicon material enables the resonator to have the advantages of stable frequency, 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 a possible implementation, the insulating layer 20 is separated between the base layer 10 and the functional layer, and a cavity 21 is formed by etching a surface of the insulating layer 20 that is opposite to the base layer 10 .

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

[0128] In a possible implementation, the length and width of the bottom pad 43 are both 100 um, the length and width of the first top pad 612 are both 100 um, and the length and width of the second top pad 622 are both 100 um.

[0129] In one possible implementation, reference Figure 5 As shown, 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, so that the cantilever beam has a sufficient length to ensure the vibration effect of the cantilever beam.

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

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

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

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

[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 a possible implementation, the thickness of the base layer 10 is 700um or 2um, the thickness of the insulating layer 20 is 2um, the width of the bus section 41 is between 10um and 20um, and the width of the extension section 611 is between 10um and 20um.

[0136] A semiconductor device provided by the present invention provides a driving voltage to the piezoelectric layer 50 through a circuit module and obtains the resonant frequency. The device is electrically connected to the circuit module through a display module. The display module 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] The invention provides a semiconductor device which uses a MEMS process to reduce the volume of a traditional resonant device and improve the stability of the semiconductor device.

[0138] A semiconductor device provided by the present invention has a top electrode 60 including a second top electrode 62 and a third top electrode 63, wherein the second top electrode 62 serves as a heating electrode and the third top electrode 63 serves as a temperature readout electrode, thereby controlling the temperature of the resonator and preventing the resonator frequency from changing due to the influence of temperature.

[0139] A semiconductor device provided by the present invention 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 together with other silicon chips to reduce the difficulty of integration and effectively reduce 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 and provide a reliable clock reference for external circuits, thereby reducing the dependence of semiconductor devices on external systems and promoting the communication industry to develop towards higher integration and higher efficiency.

[0140] Embodiment 2

[0141] The difference between the second embodiment and the first embodiment is that in the second embodiment, the bottom electrode 40 includes a matching 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-tooth structure. The reason why the frequency can be adjusted is mainly because the positive and negative electrodes have a larger area facing each other, and the amount of stored charge increases. By reasonably designing the parameters of the comb-tooth structure and the circuit connection method, the system resonant frequency and frequency response characteristics can be accurately adjusted.

[0143] Embodiment 3

[0144] The difference between the third embodiment and the first embodiment is that in the third embodiment, the bottom electrode 40 includes an auxiliary structure located in the beam structure 70, and the top electrode 60 also includes an auxiliary structure located in the beam structure 70, and neither the bottom electrode 40 nor the top electrode 60 includes the above-mentioned matching 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-tooth structure. The reason why the frequency can be adjusted is mainly because the positive and negative electrodes have a larger area facing each other, and the amount of stored charge increases. By reasonably designing the parameters of the comb-tooth structure and the circuit connection method, the system resonant frequency and frequency response characteristics can be accurately adjusted.

[0146] It should be noted here that the numerical values ​​and numerical 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 the present invention, it is necessary to understand that the terms used such as “center”, “length”, “width”, “thickness”, “top”, “bottom”, “up”, “down”, “left”, “right”, “front”, “back”, “vertical”, “horizontal”, “inside”, “outside”, “axial”, “circumferential”, etc. to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred position or component must have a specific direction, a specific structure and operation, and therefore cannot be understood as limiting the present invention.

[0148] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0149] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, they can be fixedly connected, detachably connected, or integrated; they can be mechanically connected, electrically connected, or can communicate with each other; they can be directly connected, or indirectly connected through an intermediate medium, so that the internal communication of two elements or the interaction relationship between two elements can be achieved. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0150] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A semiconductor device, characterized in that: include: A base layer (10), an insulating layer (20), and a functional layer are sequentially stacked along a first direction, the insulating layer (20) has a cavity (21) inside, the functional layer comprises an elastic layer (30) and a piezoelectric component, the elastic layer (30) is made of silicon material, and the piezoelectric component comprises a bottom electrode (40), a piezoelectric layer (50), and a top electrode (60) sequentially stacked along the first direction; The functional layer forms a beam structure (70), the beam structure (70) extends above the cavity (21), the elastic layer (30) includes a suspended portion (31) located on the beam structure (70), and at least one of the bottom electrode (40) and the top electrode (60) includes an auxiliary structure located on the beam structure (70); The auxiliary structure comprises a bus section (41) and at least two branch sections (42) connected to the bus section (41); the bus section (41) and the branch sections (42) are both arranged on the suspended portion (31), and the branch sections (42) are arranged at intervals from each other; 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, wherein: The functional layer forms a 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 further comprises a bottom pad (43) located on 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 position of the confluence segment (41); and / or, each of the branch segments (42) is connected to a different position of the confluence segment (41).

4. The semiconductor device according to claim 2, characterized in that The elastic layer (30) further comprises a supporting portion (32) located on 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).

5. The semiconductor device according to any one of claims 2 to 4, characterized in that: 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 matching structure; The matching structure comprises a first top electrode (61), the first top electrode (61) comprises an extension section (611) and a first top pad (612), the first top pad (612) is located in the main body, the extension section (611) is located in the beam structure (70), one end of the extension section (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) comprises a first part (51) and a second part (52) which are connected to each other, wherein 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 comprises a second top electrode (62) arranged on the second portion (52), the second top electrode (62) comprising a heating section (621) and a second top pad (622) connected to both ends of the heating section (621); at least part of the heating section (621) is arranged in a wavy line shape; and / or, The top electrode (60) further comprises a third top electrode (63) arranged on the second portion (52), wherein the third top electrode (63) is located close to the free end (71) so as to enable the third top electrode (63) to be electrically coupled inductively with the extension section (611).

8. The semiconductor device according to claim 5, characterized in that The material of the piezoelectric layer (50) includes a piezoelectric material, and the piezoelectric material includes aluminum nitride, lithium niobate, and zinc oxide; and / or, The material of the base layer (10) includes polysilicon material; and / or, The material of the insulating layer (20) includes silicon oxide material; and / or, The material of the elastic layer (30) includes single crystal silicon material; and / or, The material of the bottom electrode (40) includes at least one of aluminum, gold, silver, molybdenum, copper, iron, and tungsten; and / or, The material of the top electrode (60) includes at least one of aluminum, gold, silver, molybdenum, copper, iron, and tungsten.

9. The semiconductor device according to any one of claims 1 to 3, characterized in that: The insulating layer (20) is blocked between the base layer (10) and the functional layer, and the cavity (21) is formed by etching a surface of the insulating layer (20) that is opposite to the base layer (10).

10. The semiconductor device according to claim 2, wherein: 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, 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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