A MEMS magnetoelectric antenna based on on-chip bias magnetic field, its preparation method and application

Abstract

The present invention discloses a MEMS magnetoelectric antenna based on an on-chip bias magnetic field, its preparation method and application, belonging to the technical field of magnetoelectric antennas. Aiming at the problems in the prior art that the MEMS magnetoelectric antenna cannot provide a bias magnetic field inside the chip to achieve miniaturization and the bonding temperature required for preparation is high, the MEMS magnetoelectric antenna in the present invention sequentially includes a bottom substrate, an antenna substrate, an antenna end cap and a top cover from bottom to top; a MEMS bias coil cavity is provided between the bottom substrate, the antenna substrate, the antenna end cap and the top cover; an antenna sensitive structure is provided between the antenna substrate and the antenna end cap. The present invention integrates a micron-level MEMS solenoid coil in the MEMS magnetoelectric antenna chip to provide a bias magnetic field for the antenna, so that it has the best performance and a tiny volume; in addition, the MEMS magnetoelectric antenna is vacuum-packaged at a low temperature below the Curie temperature of the magnetoelectric composite material, which will not affect the performance of the magnetoelectric composite material and significantly reduces the air damping.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetoelectric antennas, and particularly to a MEMS magnetoelectric antenna based on an on-chip bias magnetic field, a preparation method thereof, and an application thereof. Background Art

[0002] Magnetoelectric antennas achieve the mutual conversion between magnetic fields and electric fields through the magnetoelectric coupling effect, can break through the constraints of antenna size and electromagnetic wavelength, and have become a current research hotspot due to their unique working principle and excellent performance. Especially in the field of low-frequency communication, compared with traditional antennas, the size of magnetoelectric antennas can be reduced by 2 to 3 orders of magnitude.

[0003] The sensitive structure of a MEMS magnetoelectric antenna is composed of a piezoelectric thin film and a magnetostrictive thin film. When it senses an external alternating magnetic field, an induced voltage is output due to the magnetoelectric coupling effect. However, there is a non-linear relationship between the output strain, output displacement of the magnetostrictive thin film and the externally applied DC magnetic field. Only by providing an appropriate bias magnetic field for the prepared magnetoelectric coupling thin film can the antenna achieve the best working performance, which undoubtedly increases the complexity and cost of the system. Therefore, it is necessary to develop a simple and feasible bias magnetic field device that can be integrated into the MEMS chip to make full use of the miniaturization advantage of MEMS technology and improve the performance of MEMS magnetoelectric antennas. This technology is particularly suitable for the biomedical field and provides an ideal solution for the interconnection and communication between implantable devices and the outside world.

[0004] The bias magnetic field of a MEMS magnetoelectric antenna can be provided by a permanent magnet or a micro-nano coil. However, the magnetic field generated by the permanent magnet material is difficult to accurately control, and it cannot ensure that the antenna is always in the best bias state. By using the method of integrating a MEMS micro-nano coil on-chip, the internal magnetic field strength can be flexibly adjusted by precisely controlling the current. This method can meet the working requirements of MEMS magnetoelectric antennas under different optimal bias magnetic fields without changing the structure or the preparation process flow of the MEMS micro-nano coil.

[0005] In a MEMS magnetoelectric antenna, the magnetostrictive material adopts a polarization mode in the length direction (L direction) to improve the output response of the sensitive structure. Therefore, the required bias magnetic field must be parallel to the substrate plane. There are two types of MEMS micro-nano coils: planar coils and solenoid coils. The on-chip planar coil not only occupies a large area and has a low inductance density, but also can only provide a bias magnetic field in the thickness direction (T direction) for the magnetostrictive thin film, and cannot meet the working requirements of the MEMS magnetoelectric antenna. By using a MEMS solenoid coil whose axis is consistent with the L polarization direction of the magnetostrictive material of the magnetoelectric antenna, the required bias magnetic field can be provided for the MEMS magnetoelectric antenna.

[0006] A low-field nuclear magnetic resonance probe based on a printed circuit board solenoid coil is proposed in the invention patent with the publication number of CN103674997B. Using a PCB substrate as the base plate, a first pad, a second pad, a group of first leads arranged side by side, and a group of second leads arranged side by side are provided on the upper surface of the PCB substrate. A group of third leads arranged side by side, a fourth lead, and a fifth lead are provided on the lower surface of the PCB substrate. It has the advantages of simple production, low cost, short cycle, and batchability. However, the line width of this printed circuit board is restricted by the process, and compared with the sensitive structure size of the MEMS magnetoelectric antenna in the micron order, it is larger and cannot meet the requirements of antenna miniaturization. In the invention patent application document with the publication number of CN104076057A, a probe based on the integration of a gallium solenoid microcoil and a glass microfluidic channel and its preparation method are proposed. The temperature parameter of the bonding process in this preparation method is 500 - 600 degrees Celsius, which exceeds the Curie temperature of the magnetoelectric composite material and will cause material modification. And the metal winding is cast with gallium, and the melting point of gallium is too low, which will limit the reliability and application scenarios of the MEMS magnetoelectric antenna. Summary of the Invention

[0007] Aiming at the above existing problems, the present invention aims to provide a MEMS magnetoelectric antenna based on an on-chip bias magnetic field, its preparation method and application. By integrating a micron-level MEMS solenoid coil in the MEMS magnetoelectric antenna chip to provide a bias magnetic field for the antenna, it has the best performance and a small volume. In addition, the MEMS magnetoelectric antenna is vacuum-packaged at a low temperature below the Curie temperature of the magnetoelectric composite material, which will not affect the performance of the magnetoelectric composite material, and significantly reduces the air damping and improves the quality factor of the sensitive structure.

[0008] In order to achieve the above object, the technical solutions adopted by the present invention are as follows:

[0009] On the one hand, the present invention provides a MEMS magnetoelectric antenna based on an on-chip bias magnetic field. The MEMS magnetoelectric antenna sequentially includes a bottom substrate, an antenna base, an antenna end cap, and a top cover from bottom to top;

[0010] There is a MEMS bias coil cavity between the bottom substrate, the antenna base, the antenna end cap, and the top cover;

[0011] There is an antenna sensitive structure between the antenna base and the antenna end cap.

[0012] Further, the top surface of the bottom substrate is provided with a plurality of long-strip bottom electrode cavities, and MEMS bias coil pads are vertically extended at the mutually separated ends of the two outermost bottom electrode cavities;

[0013] Two rows of first through-hole cavity arrays corresponding to the ends of the bottom electrode cavities are provided on the antenna base;

[0014] Two rows of second through-hole cavity arrays corresponding to the first through-hole cavity array are provided on the antenna end cap;

[0015] A plurality of top electrode cavities are provided on the top cover, and each top electrode cavity is correspondingly connected to two second through-hole cavity arrays sorted in the same order in the front-back direction;

[0016] The bottom electrode cavity, the first through-hole cavity array, the second through-hole cavity array and the top electrode cavity together form a MEMS bias coil cavity.

[0017] Furthermore, an antenna lower cavity is provided at the top center of the antenna substrate, and the antenna sensitive structure is located at the top of the antenna lower cavity;

[0018] An antenna upper cavity for accommodating the antenna sensitive structure is provided at the bottom center of the antenna end cap.

[0019] Furthermore, the antenna sensitive structure successively includes a first electrode, a piezoelectric layer, a second electrode and a magnetostrictive layer from bottom to top, and one side of the second electrode is inclined downward and then connected to the first electrode.

[0020] Furthermore, the first electrode extends to both sides and is led out to both sides of the upper surface of the antenna substrate, and antenna sensitive structure electrode pads are provided at both ends.

[0021] Furthermore, the filling material of the MEMS bias coil cavity includes any one of gold, copper, silver or nickel.

[0022] On the other hand, the present invention also provides a preparation method of a MEMS magnetoelectric antenna based on an on-chip bias magnetic field as described above, including the following steps,

[0023] Step 1: Perform dry etching treatment on the bottom substrate, antenna substrate, antenna end cap and top cover to prepare a MEMS bias coil cavity;

[0024] Step 2: Fill the electrodes of the MEMS bias coil cavity by metal electroplating process and perform polishing treatment;

[0025] Step 3: Perform silicon-silicon bonding on the bottom substrate and the antenna substrate, and the antenna end cap and the top cover respectively;

[0026] Step 4: Prepare an antenna upper cavity on the lower surface of the antenna end cap by dry etching;

[0027] Step 5: Prepare an antenna sensitive structure on the upper surface of the bonded antenna substrate;

[0028] Step 6: Align and bond the antenna substrate with the antenna sensitive structure prepared thereon and the antenna end cap.

[0029] Further, the specific operations in step 6 include the following steps:

[0030] Step 601: Electroplate a gold layer on the lower surface of the antenna end cap to prepare an intermediate layer electrode that coincides with the vertical direction projection of the second through-hole cavity array;

[0031] Step S602: Spin-coat BCB glue on the lower surface of the antenna end cap to remove the residual BCB glue on the intermediate layer electrode;

[0032] Step S603: Pre-bake the lower surface of the antenna end cap at 105 °C to remove solvents and volatile substances and partially cure the BCB glue;

[0033] Step S604: In a vacuum bonding instrument, align the upper surface of the antenna substrate with the lower surface of the antenna end cap and apply a pressure of 1 MPa to make the bonding interface in close contact;

[0034] Step S605: Heat the bonding interface to 250 °C and keep it warm for 1 hour, and then slowly cool it down to room temperature.

[0035] On the other hand, the present invention also provides an application of the MEMS magnetoelectric antenna based on the on-chip bias magnetic field as described above in a medical implantable device.

[0036] The beneficial effects of the present invention are as follows: Compared with the prior art, the improvements of the present invention are as follows:

[0037] 1. The present invention proposes a MEMS magnetoelectric antenna based on an on-chip bias magnetic field. By integrating a micron-level MEMS solenoid coil in the MEMS magnetoelectric antenna chip, a bias magnetic field is provided for the antenna, making it have optimal performance and a small volume. This technology is particularly suitable for the biomedical field and provides an ideal solution for the interconnection and communication between implantable devices and the outside world.

[0038] 2. The present invention proposes a preparation method for a MEMS magnetoelectric antenna based on an on-chip bias magnetic field. A solenoid coil that provides a bias magnetic field is manufactured through MEMS technology, and the antenna is vacuum-packaged in a low-temperature environment below the Curie temperature of the magnetoelectric composite material, which will not affect the performance of the magnetoelectric composite material and significantly reduces air damping, improving the quality factor of the sensitive structure. The entire process design is reasonable and has good repeatability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural exploded view of the MEMS magnetoelectric antenna based on the on-chip bias magnetic field in the present invention.

[0040] Figure 2 It is a structural sectional view of the antenna substrate and the antenna sensitive structure in the present invention.

[0041] Figure 3 This is a schematic diagram of the overall structure of the MEMS bias coil and antenna sensitive structure in the present invention.

[0042] Figure 4 This is a schematic diagram of the operation of preparing the first electrode on the upper surface of the antenna substrate in the present invention.

[0043] Figure 5 This is a schematic diagram of the operation of preparing the piezoelectric layer on the upper surface of the antenna substrate in the present invention.

[0044] Figure 6 This is a schematic diagram of the operation of preparing the second electrode on the upper surface of the antenna substrate in the present invention.

[0045] Figure 7 This is a schematic diagram of the operation of preparing the magnetostrictive layer on the upper surface of the antenna substrate in the present invention.

[0046] Wherein: 1. Bottom substrate; 11. Bottom electrode cavity; 111. MEMS bias coil pad; 2. Antenna substrate; 21. First through-hole cavity array; 22. Lower cavity of the antenna; 3. Antenna end cap; 31. Second through-hole cavity array; 32. Upper cavity of the antenna; 4. Top cover; 41. Top electrode cavity; 5. Antenna sensitive structure; 51. First electrode; 511. Antenna sensitive structure electrode pad; 52. Piezoelectric layer; 53. Second electrode; 54. Magnetostrictive layer. Detailed implementation manners

[0047] In order to enable those of ordinary skill in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments. Embodiment 1

[0048] Embodiment 1 provides a MEMS magnetoelectric antenna based on an on-chip bias magnetic field, as shown in the attached Figure 1-3 figure. The MEMS magnetoelectric antenna based on an on-chip bias magnetic field sequentially includes a bottom substrate 1, an antenna substrate 2, an antenna end cap 3, and a top cover 4 from bottom to top.

[0049] The top surface of the bottom substrate 1 is provided with a plurality of bottom electrode cavities 11, and the plurality of bottom electrode cavities 11 are equally spaced; the bottom electrode cavities 11 are in a strip-shaped structure, and MEMS bias coil pads 111 are vertically extended at the mutually remote ends of the outermost two bottom electrode cavities 11.

[0050] Two rows of first through-hole cavity arrays 21 are formed on the antenna substrate 2. The number of each row of the first through-hole cavity arrays 21 is one less than that of the bottom electrode cavities 11. And the two rows of the first through-hole cavity arrays 21 correspond to the ends of the bottom electrode cavities 11 (except for the extended ends of the two outermost bottom electrode cavities 11), that is, the front and rear rows of the first through-hole cavity arrays 21 are staggered in the front and rear directions. An antenna lower cavity 22 is formed at the center of the top of the antenna substrate 2, and an antenna sensitive structure 5 is provided on the top of the antenna lower cavity 22.

[0051] Two rows of second through-hole cavity arrays 31 are formed on the antenna end cap 3. The second through-hole cavity arrays 31 correspond to the first through-hole cavity arrays 21 one by one, and their projections in the vertical direction completely overlap; a central cavity 32 is formed at the bottom center of the antenna end cap 3, and the antenna upper cavity 32 corresponds to the antenna lower cavity 22.

[0052] Multiple top electrode cavities 41 are formed at the bottom of the top cover 4. The top electrode cavities 41 are inclined. Each top electrode cavity 41 correspondingly connects two second through-hole cavity arrays 31 sorted in the same order in the front and rear directions, that is, the leftmost top electrode cavity 41 connects the leftmost second through-hole cavity array 31 in the rear row and the leftmost second through-hole cavity array 31 in the front row, and so on.

[0053] In the present invention, the bottom electrode cavities 11, the first through-hole cavity arrays 21, the second through-hole cavity arrays 31 and the top electrode cavities 41 together form a MEMS bias coil cavity.

[0054] Preferably, the MEMS bias coil cavity can use gold, copper, silver or nickel as the filling material. In this embodiment, gold is selected as the filling material.

[0055] Furthermore, the antenna sensitive structure 5 is located on the top of the antenna substrate 2, and the antenna sensitive structure 5 sequentially includes a first electrode 51, a piezoelectric layer 52, a second electrode 53 and a magnetostrictive layer 54 from bottom to top. One side of the second electrode 53 is inclined downward and then connected to the first electrode 51; the first electrode 51 extends to both sides and is led out to both sides of the upper surface of the antenna substrate 2, and antenna sensitive structure electrode pads 511 are provided at both ends. The piezoelectric layer 52, the second electrode 53 and the magnetostrictive layer 54 are suspended in the antenna lower cavity 22 and the antenna upper cavity 32, and the first electrode 51 and the piezoelectric layer 52 are used as the support structure.

[0056] Preferably, in the present invention, the bottom substrate 1, the antenna substrate 2, the antenna end cap 3, and the top cover 4 are all made of double-sided polished high-resistivity silicon (resistivity > 10,000 Ω / cm), and the bottom substrate 1, the antenna substrate 2, the antenna end cap 3, and the top cover 4 have the same width dimension. The length dimension is such that the bottom substrate 1 is the longest, the antenna substrate 2 is the second longest, and the antenna end cap 3 and the top cover 4 are of equal length and the shortest. The bottom substrate 1, the antenna substrate 2, the antenna end cap 3, and the top cover 4 are bonded to form an integral structure.

[0057] The working principle of the MEMS magnetoelectric antenna based on the in-chip bias magnetic field in the present invention during actual use is as follows:

[0058] (a) The resonant frequency of the antenna sensitive structure 5 is tested through the electrode pads 511 of the antenna sensitive structure.

[0059] (b) A constant signal with the same resonant frequency as the antenna sensitive structure 5 is externally applied, and a uniform and varying DC magnetic field along the length (L) direction of the antenna sensitive structure 5 is applied through an external coil. The output signal of the antenna sensitive structure 5 is detected through the electrode pads 511 of the antenna sensitive structure. When the output signal is the strongest, the intensity of the DC magnetic field applied at this time is the corresponding optimal bias magnetic field. B ;

[0060] (c) Calculate the input current required for the MEMS bias coil (the MEMS bias coil cavity is filled with metal gold to form the MEMS bias coil) to provide the optimal bias magnetic field according to the following formula: B The input current required :

[0061] In the formula, is the vacuum permeability, n is the turn density of the coil;

[0062] (d) By applying the corresponding input current I to the MEMS bias coil pads 111, a uniform and optimal DC bias magnetic field along the length direction of the antenna sensitive structure 5 is generated inside the MEMS bias coil B , so that the antenna sensitive structure 5 is in the optimal working state. Embodiment 2

[0063] Embodiment 2 provides a preparation method for the MEMS magnetoelectric antenna based on the in-chip bias magnetic field as described in Embodiment 1, specifically including the following steps:

[0064] Step 1: Preparation of the MEMS bias coil cavity;

[0065] Specifically, the upper surface of the bottom substrate 1 is subjected to dry etching to fabricate the bottom electrode cavity 11 including the MEMS bias coil pad 111; the antenna substrate 2 is subjected to dry etching to fabricate the first via cavity array 21; the antenna end cap 3 is subjected to dry etching to fabricate the second via cavity array 31; the lower surface of the top cap 4 is subjected to dry etching to fabricate the top electrode cavity 41; the bottom electrode cavity 11, the first via cavity array 21, the second via cavity array 31, and the top electrode cavity 41 together form the MEMS bias coil cavity.

[0066] Step 2: The MEMS bias coil cavity is filled with electrodes by a metal electroplating process and polished.

[0067] Specifically, in the present invention, gold is used as the electrode material. The bottom electrode cavity 11 is electroplated with metal to form the bottom electrode, and the upper surface of the bottom substrate 1 is polished; the first via cavity array 21 is electroplated with metal to form the first via electrode array, and the upper and lower surfaces of the antenna substrate 2 are polished; the second via cavity array 31 is electroplated with metal to form the second via electrode array, and the upper and lower surfaces of the antenna end cap 3 are polished; the top electrode cavity 41 is electroplated with metal to form the top electrode, and the lower surface of the top cap 4 is polished.

[0068] Step 3: The upper surface of the bottom substrate 1 is silicon-silicon bonded to the lower surface of the antenna substrate 2, and the upper surface of the antenna end cap 3 is silicon-silicon bonded to the lower surface of the top cap 4. After bonding, the bottom electrode and the first via electrode array achieve ohmic contact connection, and the second via electrode array after bonding and the top electrode achieve ohmic contact connection.

[0069] Step 4: An upper cavity 32 of the antenna is prepared on the lower surface of the antenna end cap 3 by dry etching.

[0070] Step 5: An antenna sensitive structure 5 is prepared on the upper surface of the bonded antenna substrate 2, as shown in the attached Figure 4-7 figure, and specifically includes the following steps.

[0071] Step 501: Lithography is performed on the upper surface of the antenna substrate 2. After sputtering 100 nm of gold and stripping, a first electrode 51 including the antenna sensitive structure electrode pad 511 is fabricated on the upper surface of the antenna substrate 2, as shown in the attached Figure 4 figure.

[0072] Step 502: A 2-μm-thick ZnO piezoelectric thin film is sputtered on the upper surface of the antenna substrate 2, and after lithography and wet etching with dilute hydrochloric acid (HCl), a piezoelectric layer 52 is obtained, as shown in the attached Figure 5 figure.

[0073] Step 503: After lithography on the upper surface of the piezoelectric layer 52, a 100-nm gold layer is evaporated, and the second electrode 53 is obtained through lift-off, as shown in the appendix Figure 6 shown;

[0074] Step 504: After continuing lithography on the upper surface of the second electrode 53, a 2-μm-thick FeGaB magnetostrictive thin film is sputtered, and the magnetostrictive layer 54 is obtained through lift-off, as shown in the appendix Figure 7 shown;

[0075] Step 505: A patterned photoresist is prepared as a protective layer on the upper surface of the antenna substrate 2. The antenna substrate 2 under the antenna sensitive structure 5 is etched using XeF2 to obtain the cavity 22 on the lower side of the antenna, and finally the complete antenna substrate 2 and the antenna sensitive structure 5 as shown in the appendix are formed. Figure 2 shown.

[0076] Step 6: Align and bond the upper surface of the antenna substrate 2 with the antenna sensitive structure 5 to the lower surface of the antenna end cap 3; specifically, it includes the following steps

[0077] Step 601: On the lower surface of the antenna end cap 3, 6-μm-thick gold is electroplated, and a middle layer electrode that coincides with the vertical projection of the second via cavity array 31 is obtained using a patterning process.

[0078] Step 602: Spin-coat 5-μm-thick BCB glue on the lower surface of the antenna end cap 3, and use a patterning process and a plasma etching process to remove the residual BCB glue on the middle layer electrode.

[0079] Step 603: Pre-bake the lower surface of the antenna end cap 3 at 105 °C for 5 min to remove the solvent and volatile substances therein and partially cure the BCB glue.

[0080] Step 604: In a vacuum bonding instrument, align the upper surface of the antenna substrate 2 with the lower surface of the antenna end cap 3 so that the upper surface of the first via electrode array is aligned with the middle layer electrode, and apply a pressure of 1 MPa to make the bonding interface in close contact.

[0081] Step 605: Heat the bonding interface to 250 °C and keep it warm for 1 hour, and then slowly cool it down to room temperature.

[0082] It should be noted here that in Step 505, the reaction between XeF2 and the silicon substrate during the etching process is represented by the following formula:

[0083] The gas generated after the reaction is discharged through the vacuum system in Step 604.

[0084] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A MEMS magnetoelectric antenna based on an on-chip bias magnetic field, characterized in that: The MEMS magnetoelectric antenna sequentially includes a bottom substrate (1), an antenna substrate (2), an antenna end cap (3), and a top cover (4) from bottom to top; A MEMS bias coil cavity is provided between the bottom substrate (1), the antenna substrate (2), the antenna end cap (3), and the top cover (4); An antenna sensitive structure (5) is provided between the antenna substrate (2) and the antenna end cap (3); Among them, a plurality of strip-shaped bottom electrode cavities (11) are provided on the top surface of the bottom substrate (1), and MEMS bias coil pads (111) are vertically extended at the mutually remote ends of the two outermost bottom electrode cavities (11); Two rows of first through-hole cavity arrays (21) corresponding to the ends of the bottom electrode cavities (11) are provided on the antenna substrate (2); Two rows of second through-hole cavity arrays (31) corresponding to the first through-hole cavity arrays (21) are provided on the antenna end cap (3); A plurality of top electrode cavities (41) are provided on the top cover (4), and each top electrode cavity (41) is correspondingly connected to two second through-hole cavity arrays (31) sorted in the same order in the front-rear direction; The bottom electrode cavities (11), the first through-hole cavity arrays (21), the second through-hole cavity arrays (31), and the top electrode cavities (41) together form a MEMS bias coil cavity.

2. The MEMS magnetoelectric antenna based on an on-chip bias magnetic field according to claim 1, wherein: An antenna lower cavity (22) is provided at the top center of the antenna substrate (2), and the antenna sensitive structure (5) is located at the top of the antenna lower cavity (22); An antenna upper cavity (32) for accommodating the antenna sensitive structure (5) is provided at the bottom center of the antenna end cap (3).

3. The MEMS magnetoelectric antenna based on an on-chip bias magnetic field according to claim 2, wherein: The antenna sensitive structure (5) sequentially includes a first electrode (51), a piezoelectric layer (52), a second electrode (53), and a magnetostrictive layer (54) from bottom to top, and one side of the second electrode (53) is inclined downward and connected to the first electrode (51).

4. The MEMS magnetoelectric antenna based on an on-chip bias magnetic field according to claim 3, characterized in that: The first electrode (51) extends to both sides and is led out to both sides of the upper surface of the antenna substrate (2), and antenna sensitive structure electrode pads (511) are provided at both ends.

5. The MEMS magnetoelectric antenna based on an on-chip bias magnetic field according to claim 2, wherein: The filling material of the MEMS bias coil cavity includes any one of gold, copper, silver, or nickel.

6. The manufacturing method of a MEMS magnetoelectric antenna based on an on-chip bias magnetic field according to any one of claims 2-5, characterized in that, It includes the following steps Step 1: Perform dry etching treatment on the bottom substrate (1), the antenna substrate (2), the antenna end cap (3), and the top cover (4) to prepare a MEMS bias coil cavity; Step 2: Fill the electrodes of the MEMS bias coil cavity by metal electroplating process and perform polishing treatment; Step 3: Perform silicon-silicon bonding on the bottom substrate (1) and the antenna substrate (2), and the antenna end cap (3) and the top cover (4) respectively; Step 4: Prepare the antenna upper cavity (32) on the lower surface of the antenna end cap (3) by dry etching; Step 5: Prepare the antenna sensitive structure (5) on the upper surface of the bonded antenna substrate (2); Step 6: Align and bond the antenna substrate (2) with the antenna sensitive structure (5) prepared thereon and the antenna end cap (3).

7. The preparation method of a MEMS magnetoelectric antenna based on an on-chip bias magnetic field according to claim 6, wherein, The specific operation of Step 6 includes the following steps Step 601: Electroplate a gold layer on the lower surface of the antenna end cap (3) to prepare an intermediate layer electrode whose vertical direction projection coincides with the second through-hole cavity array (31); Step S602: Spin-coat BCB glue on the lower surface of the antenna end cap (3) to remove the residual BCB glue on the intermediate layer electrode; Step S603: Pre-bake the lower surface of the antenna end cap (3) at 105 °C to remove solvents and volatile substances and partially cure the BCB glue; Step S604: In a vacuum bonding instrument, align the upper surface of the antenna substrate (2) with the lower surface of the antenna end cap (3), and apply a pressure of 1 MPa to make the bonding interface in close contact; Step S605: Heat the bonding interface to 250 °C and keep it warm for 1 hour, and then slowly cool it down to room temperature.

8. Application of a MEMS magnetoelectric antenna based on an in-chip bias magnetic field according to any one of claims 1-5 in a medical implantable device.

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